Showing papers by "Carleton University published in 2002"

Direct evidence for neutrino flavor transformation from neutral current interactions in the Sudbury Neutrino Observatory

Abstract: Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.

Frequency domain equalization for single-carrier broadband wireless systems

Abstract: Broadband wireless access systems deployed in residential and business environments are likely to face hostile radio propagation environments, with multipath delay spread extending over tens or hundreds of bit intervals. Orthogonal frequency-division multiplex (OFDM) is a recognized multicarrier solution to combat the effects of such multipath conditions. This article surveys frequency domain equalization (FDE) applied to single-carrier (SC) modulation solutions. SC radio modems with frequency domain equalization have similar performance, efficiency, and low signal processing complexity advantages as OFDM, and in addition are less sensitive than OFDM to RF impairments such as power amplifier nonlinearities. We discuss similarities and differences of SC and OFDM systems and coexistence possibilities, and present examples of SC-FDE performance capabilities.

Parental Involvement in the Development of Children’s Reading Skill: A Five-Year Longitudinal Study

Abstract: This article presents the findings of the final phase of a 5-year longitudinal study with 168 middle- and upper middle-class children in which the complex relations among early home literacy experiences, subsequent receptive language and emergent literacy skills, and reading achievement were examined. Results showed that children's exposure to books was related to the development of vocabulary and listening comprehension skills, and that these language skills were directly related to children's reading in grade 3. In contrast, parent involvement in teaching children about reading and writing words was related to the development of early literacy skills. Early literacy skills directly predicted word reading at the end of grade 1 and indirectly predicted reading in grade 3. Word reading at the end of grade 1 predicted reading comprehension in grade 3. Thus, the various pathways that lead to fluent reading have their roots in different aspects of children's early experiences.

Measurement of Day and Night Neutrino Energy Spectra at SNO and Constraints on Neutrino Mixing Parameters

Abstract: The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

IARC Monographs on the evaluation of carcinogenic risks to humans: Some traditional herbal medicines, some mycotoxins, naphthalene and styrene

Abstract: Members Ahti Anttila, Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Liisankatu 21 B, 00170 Helsinki, Finland Ramesh V. Bhat, National Institute of Nutrition, Indian Council of Medical Research, Jamai-Osmania PO, Hyderabad-500 007 AP, India James A. Bond, Chemico-Biological Interactions, Toxcon, 5505 Frenchmans Creek, Durham, NC 27713, USA Susan J. Borghoff, CIIT Centers for Health Research, 6 Davis Drive, Box 12137, Research Triangle Park, NC 27709-2127, USA F. Xavier Bosch, Epidemiology Unit and Cancer Registry, Catalan Institute of Oncology, Av. Gran via s/n, Km. 2.7, 08907 L’Hospitalet del Llobregat, Spain Gary P. Carlson, School of Health Sciences, 1338 Civil Engineering Building, Purdue University, West Lafayette, IN 47907-1338, USA Marcel Castegnaro, Les Collanges, 07240 Saint-Jean-Chambre, France George Cruzan, ToxWorks, 1153 Roadstown Road, Bridgeton, NJ 08302-6640, USA Wentzel C.A. Gelderblom, Programme on Mycotoxins and Experimental Carcinogenesis, Medical Research Council (MRC), PO Box 19070, Tygerberg, South Africa 7505 Ulla Hass, Institute of Food Safety and Toxicology, Morkhoj Bygade 19, 2860 Soborg, Denmark Sara H. Henry, 5100 Paint Branch Parkway, College Park, MD 20740-3835, USA Ronald A. Herbert, Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, PO Box 12233, Mail Drop B3-08, Research Triangle Park, NC 27709-2233, USA Marc Jackson, Integrated Laboratory Systems, Inc., PO Box 13501, Research Triangle Park, NC 27709, USA IARC WORKING GROUP ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS: SOME TRADITIONAL HERBAL MEDICINES, SOME MYCOTOXINS, NAPHTHALENE AND STYRENE

Effect of habitat fragmentation on the extinction threshold: a synthesis*

Abstract: I reviewed and reconciled predictions of four models on the effect of habitat fragmentation on the population extinction threshold, and I compared these predictions to results from empirical studies. All four models predict that habitat fragmentation can, under some conditions, increase the extinction threshold such that, in more fragmented landscapes, more habitat is required for population persistence. However, empirical studies have shown both positive and negative effects of habitat fragmentation on population abundance and distribution with about equal frequency, suggesting that the models lack some important process(es). The two colonization–extinction (CE) models predict that fragmentation can increase the extinction threshold by up to 60–80%; i.e., the amount of habitat required for persistence can shift from 80% of the landscape, with a shift from completely clumped to completely fragmented habitat. The other two models (birth–immigration–death–emigration, or BIDE models)...

Country equity and country branding: Problems and prospects

Abstract: This paper surveys and reviews the voluminous research on product-country images and their effects, with the objectives of discussing the multi-faceted nature of country equity and its importance, and identifying knowledge gaps and misconceptions that often impede the development of successful business or national strategies based on effective country branding. The paper concludes that country-based marketing is often underused or misdirected due to inadequate understanding of the meaning of 'country branding', and suggests approaches for strategy development as well as pointing to knowledge gaps that call for additional research.

The Quasicontinuum Method: Overview, applications and current directions

Abstract: The Quasicontinuum (QC) Method, originally conceived and developed by Tadmor, Ortiz and Phillips [1] in 1996, has since seen a great deal of development and application by a number of researchers The idea of the method is a relatively simple one With the goal of modeling an atomistic system without explicitly treating every atom in the problem, the QC provides a framework whereby degrees of freedom are judiciously eliminated and force/energy calculations are expedited This is combined with adaptive model refinement to ensure that full atomistic detail is retained in regions of the problem where it is required while continuum assumptions reduce the computational demand elsewhere This article provides a review of the method, from its original motivations and formulation to recent improvements and developments A summary of the important mechanics of materials results that have been obtained using the QC approach is presented Finally, several related modeling techniques from the literature are briefly discussed As an accompaniment to this paper, a website designed to serve as a clearinghouse for information on the QC method has been established at wwwqcmethodcom The site includes information on QC research, links to researchers, downloadable QC code and documentation

A stable isotope (δ13C, δ15N) model for the North Water food web: implications for evaluating trophodynamics and the flow of energy and contaminants

Abstract: The North Water Polynya is an area of high biological activity that supports large numbers of higher trophic-level organisms such as seabirds and marine mammals. An overall objective of the Upper Trophic-Level Group of the International North Water Polynya Study (NOW) was to evaluate carbon and contaminant flux through these high trophic-level (TL) consumers. Crucial to an evaluation of the role of such consumers, however, was the establishment of primary trophic linkages within the North Water food web. We used δ15N values of food web components from particulate organic matter (POM) through polar bears (Ursus maritimus) to create a trophic-level model based on the assumptions that Calanus hyperboreus occupies TL 2.0 and there is a 2.4‰ trophic enrichment in 15N between birds and their diets, and a 3.8‰ trophic enrichment for all other components. This model placed the planktivorous dovekie (Alle alle) at TL 3.3, ringed seal (Phoca hispida) at TL 4.5, and polar bear at TL 5.5. The copepods C. hyperboreus, Chiridius glacialis and Euchaeta glacialis formed a trophic continuum (TL 2.0–3.0) from primary herbivore through omnivore to primary carnivore. Invertebrates were generally sorted according to planktonic, benthic and epibenthic feeding groups. Seabirds formed three trophic groups, with dovekie occupying the lowest, black-legged kittiwake (Rissa tridactyla), northern fulmar (Fulmarus glacialis), thick-billed murre (Uria aalge), and ivory gull (Pagophilia eburnea) intermediate (TL 3.9–4.0), and glaucous gull (Larus hyperboreus) the highest (TL 4.6) trophic positions. Among marine mammals, walrus (Odobenus rosmarus) occupied the lowest (TL 3.2) and bearded seal (Erignathus barbatus), ringed seal, beluga whale (Delphinapterus leucas), and narwhal (Monodon monoceros) intermediate positions (TL 4.1–4.6). In addition to arctic cod (Boreogadus saida), we suggest that lower trophic-level prey, in particular the amphipod Themisto libellula, contribute fundamentally in transferring energy and carbon flux to higher trophic-level seabirds and marine mammals. We measured PCB 153 among selected organisms to investigate the behavior of bioaccumulating contaminants within the food web. Our isotopic model confirmed the trophic magnification of PCB 153 in this high-Arctic food web due to a strong correlation between contaminant concentration and organism δ15N values, demonstrating the utility of combining isotopic and contaminant approaches to food-web studies. Stable-carbon isotope analysis confirmed an enrichment in 13C between POM and ice algae (–22.3 vs. –17.7‰). Benthic organisms were generally enriched in 13C compared to pelagic species. We discuss individual species isotopic data and the general utility of our stable isotope model for defining carbon flux and contaminant flow through the North Water food web.

A UML-Based Approach to System Testing

Abstract: System testing is concerned with testing an entire system based on its specifications. In the context of object-oriented, UML development, this means that system test requirements are derived from UML analysis artifacts such as use cases, their corresponding sequence and collaboration diagrams, class diagrams, and possibly Object Constraint Language (OCL) expressions across all these artifacts. Our goal here is to support the derivation of functional system test requirements, which will be transformed into test cases, test oracles, and test drivers once we have detailed design information. In this paper, we describe a methodology in a practical way and illustrate it with an example. In this context, we address testability and automation issues, as the ultimate goal is to fully support system testing activities with high-capability tools.

An Evaluation of Research on Integrated Product Development

Abstract: Integrated Product Development (IPD) creates overlap and interaction between activities in the new product development process and, because this increases the need to coordinate, compensates through other aspects of the new product development process (e.g., integrated tools), product definitions (e.g., incremental development), organizational context (e.g., reduced task specialization), and teaming (e.g., cross-functional teams). Since IPD has become an important new standard for managing new product development, this paper's general aim is to evaluate the research that has been conducted on it. Our three specific objectives include first critiquing the IPD literature by identifying problems with empirical research and recommending solutions. There are concerns about the overall approach, conceptualizing and operationalizing IPD characteristics, and selecting performance objectives. Second, we conduct a meta-analysis to evaluate relationships between specific IPD characteristics and project performance. We indicate where relationships do or do not exist and identify variables that may moderate these relationships. Third, we offer suggestions for extending IPD research into studies of (a) the hierarchy of teams working on a project, (b) one company managing a portfolio of projects over time, and (c) two or more firms collaborating in a strategic alliance.

Measurement of the rate of ν e +d→p+p+e - interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory

Abstract: Solar neutrinos from the decay of 8B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to ν e, while the ES reaction also has a small sensitivity to ν μ and ν τ. The flux of ν e from 8B decay measured by the CC reaction rate is φ CC(ν e )=[1.75±0.07(stat.) −0.11 +0.12 (syst.)×0.05(theor.)]×106cm−2s−1. Assuming no flavor transformation, the flux inferred from the ES reaction rate is φ ES(ν x )=[2.39±0.34(stat.) −0.14 +0.16 (syst.)]×106cm−2s−1. Comparison of φ CC(ν e) to the Super-Kamiokande collaboration’s precision value of φ ES(ν x) yields a 3.3σ difference, assuming the systematic uncertainties are normally distributed, providing evidence that there is a nonelectron flavor active neutrino component in the solar flux. The total flux of active 8B neutrinos is thus determined to be (5.44±0.99)×106 cm−2 s−1, in close agreement with the predictions of solar models.

Improved models for the generation of multiple uncorrelated Rayleigh fading waveforms

Abstract: An improved sum-of-sinusoids simulation model is proposed for Rayleigh fading channels. The new model employs random initial phase, and conditional random Doppler frequency for all individual sinusoids. The second-order statistics of the new simulator match the desired ones exactly even if the number of sinusoids is a single-digit integer. Other key statistics of the new simulator approach the desired ones of Clarke's (1968) reference model as the number of sinusoids approaches infinity, while good convergence is achieved when the number of sinusoids is small. Moreover, the new simulator can be directly used to generate multiple uncorrelated fading waveforms; it is also pointed out that a class of 16 different simulators, which have identical statistical properties, can be developed for Rayleigh fading channels.

Dispersal distance of mammals is proportional to home range size

Abstract: We tested the prediction that home range area and dispersal distance in mammals are related when considered independently of body size. Regression of log- transformed data demonstrated that more variance in maximum dispersal distance could be explained by home range area (74%) than could be explained by body size (50%). The relationship between maximum dispersal distance and home range size was isometric (slope 5 1) when the square root of home range area (i.e., linear dimension of home range) was used. Thus, maximum dispersal distance was related to home range size by a single constant of 40. A linear relationship remained between these two variables after the effects of body size were removed (F 5 31.6, df 5 1, 32, P 5 3.2 3 10 26 , R 2 5 0.50). A similar isometric relationship with home range size was found for median dispersal distance (related by a multiple of 7). This isometric relationship between dispersal distance and home range size was tested using a second data source: maximum movements made by mammals after translocation, which also was linearly related to home range area (F 5 94.5, df 5 1, 23, P 5 1.3 3 10 29 , R 2 5 0.81). The slope and intercept of this relationship were not different from those of the relationship between maximum dispersal distance and home range area. We suggest that the vagility of mammals affected both home range size and dispersal distance (or movement after translocation) independently of body size, such that these movements could be predicted by home range area better than by body size alone. The resulting isometric relationship between dispersal distance and home range size has potential as a useful scaling rule for ecological practitioners.

Assessing the applicability of fault-proneness models across object-oriented software projects

Abstract: A number of papers have investigated the relationships between design metrics and the detection of faults in object-oriented software. Several of these studies have shown that such models can be accurate in predicting faulty classes within one particular software product. In practice, however, prediction models are built on certain products to be used on subsequent software development projects. How accurate can these models be, considering the inevitable differences that may exist across projects and systems? Organizations typically learn and change. From a more general standpoint, can we obtain any evidence that such models are economically viable tools to focus validation and verification effort? This paper attempts to answer these questions by devising a general but tailorable cost-benefit model and by using fault and design data collected on two mid-size Java systems developed in the same environment. Another contribution of the paper is the use of a novel exploratory analysis technique - MARS (multivariate adaptive regression splines) to build such fault-proneness models, whose functional form is a-priori unknown. The results indicate that a model built on one system can be accurately used to rank classes within another system according to their fault proneness. The downside, however, is that, because of system differences, the predicted fault probabilities are not representative of the system predicted. However, our cost-benefit model demonstrates that the MARS fault-proneness model is potentially viable, from an economical standpoint. The linear model is not nearly as good, thus suggesting a more complex model is required.

Climate and the limits of permafrost: a zonal analysis

Abstract: This paper defines the climatic and environmental conditions that determine the limits and continuity of permafrost occurrence, in the Canadian context. The analysis utilizes a functional model that links air, surface and permafrost temperature through seasonal surface transfer functions and subsurface thermal properties. The temperature of permafrost (TTOP) results from the interplay between the air temperature, the nival (snow) offset and the thermal offset. These offset values vary systematically and geographically with freezing and thawing indices, snow cover conditions and ground thermal properties. These effects are analysed by calculating offset and TTOP values using Canadian climate station data for air temperature and snowfall. Whilst permafrost is ultimately a climatic phenomenon, the ground thermal conductivity ratio, via the thermal offset, is shown to be the critical factor in determining the southernmost extent of (discontinuous) permafrost. In contrast, snow cover, via the nival offset, is the critical factor in determining the northern limit of discontinuous permafrost (i.e. southern limit of continuous permafrost). Calculated TTOP values increase gradually southwards towards the limit of permafrost occurrence, as the effect of a rising mean annual air temperature (MAAT) is counteracted by an increasing thermal offset. This results in a diffuse geographical transition in the disappearance of permafrost. In contrast, there is a more abrupt transition to continuous permafrost at the northern limit of the discontinuous zone, associated with geographical changes in snow cover and the associated nival offset. The transition from discontinuous to continuous permafrost occurs between a MAAT of −6° to −8°C. This may explain the air temperature limit for continuous permafrost cited by previous authors. Copyright © 2002 John Wiley & Sons, Ltd.

Mapping Schengenland: Denaturalizing the Border

Abstract: In this paper I examine the reorganization of border controls associated with the Schengen process in the European Union and some of its close neighbours. Rather than asking the political science question of why states are committed to Schengen (or not, in the case of the United Kingdom and Ireland), I interpret Schengen as a political moment for genealogical reflection and analysis. The purpose is to contribute to a more historicized understanding of borders. Schengen is analyzed in terms of three trajectories, each of which allows us to denaturalize certain key aspects of the border, such as its identity, function, rationality, and contingency. Schengen is theorized in relation to the geopolitical border, the national border, and the biopolitical border. Other possibilities for genealogies of the border are also canvassed.

Vapor pressures, aqueous solubilities, and Henry's law constants of some brominated flame retardants.

Abstract: The subcooled liquid vapor pressures (P0(L),25S) and aqueous solubilities (Sw,25s) were determined and Henry's law constants (H25s) were estimated for a number of brominated flame retardants (BFRs) at 25 degrees C. The established methods of the gas chromatography-retention time and generator column techniques were used to experimentally determine P0(L),25 and Sw,25 for hexabromobenzene and a series of brominated diphenyl ether (BDE) congeners. The H25 was estimated as the ratio of P0(L)25 to the subcooled liquid aqueous solubility. Values of PL0(L),25 obtained ranged from 0.000000282 Pa (BDE-190) to 0.259 Pa (BDE-3); Sw,25 ranged from 0.00000087 g/L (BDE-153 and BDE-154) to 0.00013 g/L (BDE-15); and H25 ranged from 0.0074 Pa m3/mol (BDE-183) to 21 Pa m3/mol (BDE-15). An increase in the bromine content of polybrominated diphenyl ether congeners resulted in significant decreases Of P0(L),25, Sw25, and H25. A simple four-compartment equilibrium distribution model suggested that the majority of BFRs being released into the environment would reside in soil and sediment and have localized distributions. The model also suggested that lower brominated congeners tend to be somewhat more mobile. Degradative debromination reactions that yield these congeners would mobilize them environmentally, and ultimately affect the fate and distribution of BFRs.

Using anthropogenic contaminants and stable isotopes to assess the feeding ecology of greenland sharks

Abstract: Organochlorine contaminants (OCs) are a large group of ubiquitous pollutants that have potential as tracers of ecological processes. To examine this utility, we measured OCs, stable isotopes of nitrogen (δ15N) and carbon (δ15C), and stomach contents in a large Arctic marine fish, the Greenland shark (Somniosus microcephalus), collected in the Davis Strait region to examine the feeding ecology of this little studied elasmobranch. Stable isotopes and OCs were also measured in the turbot (Reinhardtius hippoglossoides) and stable isotopes in the ringed seal (Phoca hispida) and harp seal (Pagophilus groenlandicus) to put the shark results in context. Values of δ15N suggest that the Greenland shark feeds at a similar trophic level as the turbot and ringed seal (about the fourth trophic level) and at a higher trophic level than harp seals, despite the presence of many turbot and a single ringed seal in the stomach contents of 14 sharks. Values of δ13C indicate that source of carbon in turbot and Greenland shark ...

A White-Box DES Implementation for DRM Applications

Abstract: For digital rights management (drm) software implementations incorporating cryptography, white-box cryptography (cryptographic implementation designed to withstand the white-box attack context) is more appropriate than traditional black-box cryptography. In the white-box context, the attacker has total visibility into software implementation and execution. Our objective is to prevent extraction of secret keys from the program. We present methods to make such key extraction difficult, with focus on symmetric block ciphers implemented by substitution boxes and linear transformations. A des implementation (useful also for triple-des) is presented as a concrete example.

CD++: a toolkit to develop DEVS models

Abstract: The features of a toolkit for modeling and simulation based on the DEVS formalism are presented. The tool is built as a set of independent software pieces running on different platforms. Not only are the main characteristics of the environment presented, a focus on its use is also considered by inclusion of application examples for a variety of problems. Many models can be defined in an automated fashion, simplifying the construction of new models and easing their verification. The use of this formal approach has allowed the development of safe and cost-effective simulations, significantly reducing development time.

Cytokines, stress, and depressive illness.

Abstract: It has been suggested that immune activation, and particularly increased activity of several cytokines, notably interleukin-1, interleukin-2, interleukin-6, tumor necrosis factor-alpha as well as their soluble receptors is characteristic of depression. Normalization of cytokine activity does not necessarily occur following successful antidepressant, suggesting that cytokines may be trait markers of depression, or simply represent bystander effects of the illness. The relationship between cytokines and depression is complicated as a variety factors could directly or indirectly influence cytokine activity. While cytokine elevations are most pronounced in severe (melancholic) depression, their activity may also be related to chronicity of illness, neurovegetative features of depression (altered sleep patterns, food intake, weight changes, fatigue or general activity), or the high stress perception characteristic of depression. Although, studies assessing cytokines in depressive populations are basically correlational in nature, patients receiving cytokine immunotherapy frequently show depressive symptoms, which may be attenuated by antidepressant medication, supporting a causal role for cytokines in depressive disorders. The processes underlying such outcomes remain to be established, but the affective changes may stem from the neuroendocrine and central neurochemical changes elicited by cytokines, as these are reminiscent of those associated thought to subserve depression.

Authoritative and Authoritarian Mothers' Parenting Goals, Attributions, and Emotions Across Different Childrearing Contexts

Abstract: Objective. The central goal of this study was to explore how childrearing contexts might moderate relations between parenting styles and mothers' parental beliefs and emotional responses. Design. Participants were 76 mothers of children (41 boys, 35 girls) ranging in age from 30 to 70 months. Mothers completed a global measure of parenting styles (authoritarian, authoritative). Self-reports of parental beliefs (parental goals, attributions) and emotional responses (angry, embarrassed, happy) were assessed in response to hypothetical vignettes depicting a variety of children's behaviors (aggression, misbehavior, shyness, prosocial behavior). Results. In situations depicting children's negative behaviors, authoritarian mothers were less focused on empathic goals and attributed child aggression and misbehaviors to less external sources than their more authoritative counterparts. Authoritarian mothers were also more likely to respond with greater anger and embarrassment across all childrearing scenarios. Conc...

Life in the slow lane: molecular mechanisms of estivation.

Abstract: Estivation is a state of aerobic hypometabolism used by organisms to endure seasonally arid conditions, often in desert environments. Estivating species are often active for only a few weeks each year to feed and breed and then retreat to estivate in sheltered sites, often underground. In general, estivation includes a strong reduction in metabolic rate, a primary reliance on lipid oxidation to fuel metabolism, and methods of water retention, both physical (e.g. cocoons) and metabolic (e.g. urea accumulation). The present review focuses on several aspects of metabolic adaptation during estivation including changes in the activities of enzymes of intermediary metabolism and antioxidant defenses, the effects of urea on estivator enzymes, enzyme regulation by reversible protein phosphorylation, protein kinases and phosphatases involved in signal transduction mechanisms, and the role of gene expression in estivation. The focus is on two species: the spadefoot toad, Scaphiopus couchii, from the Arizona desert; and the land snail, Otala lactea, a native of the Mediterranean region. The mechanisms of metabolic depression in estivators are similar to those seen in hibernation and anaerobiosis, and contribute to the development of a unified set of biochemical principles for the control of metabolic arrest in nature.

Search for Charmless [Formula presented] Decays

Abstract: We have studied two-body charmless decays of the $B$ meson into the final states $\rho^0 \rho^0$, $K^{*0} \rho^0$, $K^{*0} K^{*0}$, $K^{*0} \bar{K^{*0}}$, $K^{*+} \rho^0$, $K^{*+} \bar{K^{*0}}$, and $K^{*+} K^{*-}$ using only decay modes with charged daughter particles. Using 9.7 million $B \bar{B}$ pairs collected with the CLEO detector, we place 90% confidence level upper limits on the branching fractions, $(0.46-7.0)\times 10^{-5}$, depending on final state and polarization.