bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear Stability Analysis and Validation of a Unified Solution Method for Fluid-Structure-Interaction on Structural Dynamic Problems
Authors: Giannopapa C. G. , Papadakis G.
Published: August 2008

In the conventional approach for fluid-structure interaction problems, the fluid and solid components are treated separately and information is exchanged across their interface. According to the conventional terminology, the current numerical methods can be grouped in two major categories: Partitioned methods and monolithic methods. Both methods use two separate sets of equations for fluid and solid. A unified solution method has been presented [1], which is different from these methods. The new method treats both fluid and solid as a single continuum, thus the whole computational domain is treated as one entity discretised on a single grid. Its behavior is described by a single set of equations, which are solved fully implicitly. In this paper, 2 time marching and one spatial discretisation scheme, widely used for fluids’ equations, are applied for the solution of the equations for solids. Using linear stability analysis, the accuracy and dissipation characteristics of the resulting difference equations are examined. The aforementioned schemes are applied to a transient structural problem (beam bending) and the results compare favorably with available analytic solutions and are consistent with the conclusions of the stability analysis. A parametric investigation using different meshes, time steps and beam sizes is also presented. For all cases examined the numerical solution was stable and robust and proved to be suitable for the next stage of application to full fluid-structure interaction problems.
BEM Modeling of Non Linear Systems Noise
Authors: Alia Ahlem , Souli Mhamed
Published: August 2008

A noticeable part of acoustic environment is made of sounds radiated by vibrating structures. Most of these sounds are considered as undesirable noise. Especially, those radiated from complex processes involving several non linear effects. In the present work, the transient response of mechanical system is computed first by using LSDYNA, an explicit finite element code for general fluid, structure and fluid-structure interaction problems. By applying the FFT, it’s transformed into frequency response which allows to use BEM for computing the noise radiated at any point into space. Results are checked for simple acoustic and classical vibroacoustic problems before applying it for a non linear case. The numerical examples show the efficiency of the present method.
Waterjet Cutting: State of the Art and Future Trends
Authors: Trieb Franz H.
Published: August 2008

Waterjet cutting is used in various fields and applications. Materials difficult to machine, small series production and complex geometry is easy to handle with this cutting process. Frozen food, leather and plastic as well as stone, glass and steel are materials which can be cut by waterjet or abrasive waterjet. The efficiency of the cutting technology is depending mainly on the pump system and the installed high pressure cutting equipment. Maximum working pressure, flow rate of water and the reliability of the high pressure pump influences flexibility, velocity and finally the costs of each cut. This paper presents the actual technical state of the art for waterjet cutting and gives an overview on cutting tests with ultra high pressure up to 800 MPa.
Numerical Study of Liquid Dynamics in Partially Filled Circular Tanks
Authors: Xu Liang , Dai Liming
Published: August 2008

The liquid dynamics in partially filled circular tanks has been studied by numerically solving the natural frequencies and transient liquid motion. The governing equations for liquid in tanks are based on the potential flow theory. Instead of direct discretization in the 2D circular area, the governing equations are rearranged in such a way that the discretization is performed in a fixed square area by continuous coordinate mappings to overcome the difficulties in dealing with the boundary conditions on the circular edge and the free surface. The natural frequencies of liquid sloshing in partially filled circular tanks are determined by solving generalized eigenvalue problem of liquid under different fill levels. Transient liquid motion is simulated when the tank is subjected to motion in the lateral direction, which is represented by different prescribed lateral accelerations. The forces caused by the change of liquid pressure on the tank walls are calculated.
Development of U.S. Regulations for the Transportation of Radioactive Materials: A Look Back Over the Past 40 Years
Authors: Hafner Ronald S.
Published: August 2008

This paper describes an overview of the development of U.S. regulations for the transportation of radioactive materials over the past 40 years. In general, the primary focal points are multifaceted. In particular, however, this rather complex approach has been reduced to two major topical areas: 1) The detailed interactions that have long been in place between the U.S. Regulatory agencies involved, i.e., the older U.S. Interstate Commerce Commission and its more modern counterpart, the U.S. Department of Transportation, and the older U.S. Atomic Energy Agency and its more modern counterpart, the U.S. Nuclear Regulatory Commission; and 2) the detailed interactions that have long been in place between the U.S. Regulatory agencies and those of the International Atomic Energy Agency. Although the primary time period covered in this work will be between 1965 and 2004, some of the discussion, by necessity, dates back to 1958.
Computational Solutions of Unsteady Confined Viscous Flows With Variable Inflow Velocities for Unsteady Fluid-Structure Interaction Problems
Authors: Mateescu Dan , Mei Chuan Bin , Zuppel Eddy
Published: August 2008

This paper presents computational solutions of the unsteady viscous flows generated by the variation in time of the inflow velocities. These solutions are obtained using a specially developed time-accurate numerical method for the solution of the time-dependent Navier-Sokes equations. This method is applied to obtain solutions for the unsteady viscous flows past downstream-facing steps which are generated by harmonic variations in time of the inflow velocities. Complex flow separation patterns were found for these unsteady flows.
Consonant confusions in white noise
Authors: Phatak Sandeep A. , Lovitt Andrew , Allen Jont B.
Published: August 2008

The classic [MN55] confusion matrix experiment (16 consonants, white noise masker) was repeated by using computerized procedures, similar to those of Phatak and Allen (2007). [“Consonant and vowel confusions in speech-weighted noise,” J. Acoust. Soc. Am. 121, 2312–2316]. The consonant scores in white noise can be categorized in three sets: low-error set {/m/, /n/}, average-error set {/p/, /t/, /k/, /s/, /ʃ/, /d/, /g/, /z/, /ʒ/}, and high-error set {/f/,/θ/,/b/, /v/, /ð/}. The consonant confusions match those from MN55, except for the highly asymmetric voicing confusions of fricatives, biased in favor of voiced consonants. Masking noise cannot only reduce the recognition of a consonant, but also perceptually morph it into another consonant. There is a significant and systematic variability in the scores and confusion patterns of different utterances of the same consonant, which can be characterized as (a) confusion heterogeneity, where the competitors in the confusion groups of a consonant vary, and (b) threshold variability, where confusion threshold [i.e., signal-to-noise ratio (SNR) and score at which the confusion group is formed] varies. The average consonant error and errors for most of the individual consonants and consonant sets can be approximated as exponential functions of the articulation index (AI). An AI that is based on the peak-to-rms ratios of speech can explain the SNR differences across experiments.
Verifying the attenuation of earplugs in situ: Method validation using artificial head and numerical simulations
Authors: Bockstael Annelies , de Greve Bram , Van Renterghem Timothy , Botteldooren Dick , D’Haenens Wendy , Keppler Hannah , Maes Leen , Philips Birgit , Swinnen Freya , Vinck Bart
Published: August 2008

The use of in situ measurements of hearing protectors’ (HPD’s) attenuation following the microphone in real ear (MIRE) protocol is increasing. The attenuation is hereby calculated from the difference in sound levels outside the ear and inside the ear canal behind the HPD. Custom-made earplugs have been designed with an inner bore that allows inserting a miniature microphone. A thorough understanding of the difference, henceforth called transfer function, between the sound pressure of interest at the eardrum and the one measured at the inner bore of the HPD is indispensable for optimizing the MIRE technique and extending its field of application. This issue was addressed by measurements on a head-and-torso-simulator and finite difference time domain numerical simulations of the outer ear canal occluded by an earplug. Both approaches are in good agreement and reveal a clear distinction between the sound pressure at the MIRE microphone and at eardrum, but the measured transfer functions appear to be stable and reproducible. Moreover, the most striking features of the transfer functions can be traced down to the geometrical and morphological characteristics of the earplug and ear canal.
The Anthrax Vaccine Adsorbed Vaccine Generates Protective Antigen (PA)-Specific CD4
+
T Cells with a Phenotype Distinct from That of Naïve PA T Cells
Authors: Kwok William W. , Yang Junbao , James Eddie , Bui John , Huston Laurie , Wiesen Andrew R. , Roti Michelle
Published: August 2008

Cellular immune responses against protective antigen (PA) of
Bacillus anthracis
in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4
+
T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4
+
T cells with a CD45RA
−
phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4
+
T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA
+
and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4
+
T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4
+
T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4
+
cell responses and lineage development after vaccination.
Characterization of Chromosomal Regions Conserved in
Yersinia pseudotuberculosis
and Lost by
Yersinia pestis
Authors: Pouillot Flavie , Fayolle Corinne , Carniel Elisabeth
Published: August 2008

The transformation of the enteropathogenic bacterium
Yersinia pseudotuberculosis
into the plague bacillus,
Yersinia pestis
, has been accompanied by extensive genetic loss. This study focused on chromosomal regions conserved in
Y. pseudotuberculosis
and lost during its transformation into
Y. pestis
. An extensive PCR screening of 78 strains of the two species identified five regions (R1 to R5) and four open reading frames (ORFs;
orf1
to
orf4
) that were conserved in
Y. pseudotuberculosis
and absent from
Y. pestis
. Their conservation in
Y. pseudotuberculosis
suggests a positive selective pressure and a role during the life cycle of this species. Attempts to delete two ORFs (
orf3
and
orf4
) from the chromosome of strain IP32953 were unsuccessful, indicating that they are essential for its viability. The seven remaining loci were individually deleted from the IP32953 chromosome, and the ability of each mutant to grow in vitro and to kill mice upon intragastric infection was evaluated. Four loci (
orf1
, R2, R4, and R5) were not required for optimal growth or virulence of
Y. pseudotuberculosis
. In contrast,
orf2
, encoding a putative pseudouridylate synthase involved in RNA stability, was necessary for the optimal growth of IP32953 at 37°C in a chemically defined medium (M63S). Deletion of R1, a region predicted to encode the methionine salvage pathway, altered the mutant pathogenicity, suggesting that the availability of free methionine is severely restricted in vivo. R3, a region composed mostly of genes of unknown functions, was necessary for both optimal growth of
Y. pseudotuberculosis
at 37°C in M63S and for virulence. Therefore, despite their loss in
Y. pestis
, five of the nine
Y. pseudotuberculosis
-specific chromosomal loci studied play a role in the survival, growth, or virulence of this species.
Toxoplasma gondiiRhoptry Discharge Correlates with Activation of the Early Growth Response 2 Host Cell Transcription Factor
Authors: Phelps Eric D. , Sweeney Kristin R. , Blader Ira J.
Published: August 2008

Toxoplasma gondiiis a ubiquitous apicomplexan parasite that can cause severe disease in fetuses and immune-compromised patients. Rhoptries, micronemes, and dense granules, which are secretory organelles unique toToxoplasmaand other apicomplexan parasites, play critical roles in parasite growth and virulence. To understand how these organelles modulate infected host cells, we sought to identify host cell transcription factors triggered by their release. Early growth response 2 (EGR2) is a host cell transcription factor that is rapidly upregulated and activated inToxoplasma-infected cells but not in cells infected with the closely related apicomplexan parasiteNeospora caninum. EGR2 upregulation occurred only when live parasites were in direct contact with the host cell and not from exposure to cell extracts that contain dense granule or micronemal proteins. When microneme-mediated attachment was blocked by pretreating parasites with a calcium chelator, EGR2 expression was significantly reduced. In contrast, when host cells were infected with parasites in the presence of cytochalasin D, which allows rhoptry secretion but prevents parasite invasion, EGR2 was activated. Finally, we demonstrate thatToxoplasmaactivation of host p38 mitogen-activated protein kinase is necessary but not sufficient for EGR2 activation. Collectively, these data indicate that EGR2 is specifically upregulated by a parasite-derived secreted factor that is most likely a resident rhoptry protein.
Priority dilemmas in dialysis: the impact of old age
Authors: Halvorsen K , Slettebø Å , Nortvedt P , Pedersen R , Kirkevold M , Nordhaug M , Brinchmann B S
Published: July 2008

Aim:

This study explores priority dilemmas in dialysis treatment and care offered elderly patients within the Norwegian public healthcare system.

Background:

Inadequate healthcare due to advanced age is frequently reported in Norway. The Norwegian guidelines for healthcare priorities state that age alone is not a relevant criterion. However, chronological age, if it affects the risk or effect of medical treatment, can be a legitimate criterion.

Method:

A qualitative approach is used. Data were collected through semistructured interviews and analysed through hermeneutical content analysis. The informants were five physicians and four nurses from dialysis wards.

Findings:

Pressing priority dilemmas centre around decision-making concerning withholding and withdrawal of dialysis treatment. Advanced age is rarely an absolute or sole priority criterion. It seems, however, that advanced age appears to be a more subtle criterion in relation with, for example, comorbidity, functional status and cognitive impairment. Nurses primarily prioritise specialised dialysis care and not comprehensive nursing care. The complex needs of elderly patients are therefore often not always met.

Conclusions:

Clinical priorities should be made more transparent in order to secure legitimate and fair resource allocation in dialysis treatment and care. Difficult decisions concerning withholding or withdrawal of dialysis ought to be openly discussed within the healthcare team as well as with patients and significant others. The biomedical focus and limitations on comprehensive care during dialysis should be debated.
When the boss turns pusher: a proposal for employee protections in the age of cosmetic neurology
Authors: Appel J M
Published: July 2008

Neurocognitive enhancement, or cosmetic neurology, offers the prospect of improving the learning, memory and attention skills of healthy individuals well beyond the normal human range. Much has been written about the ethics of such enhancement, but policy-makers in the USA, the UK and Europe have been reluctant to legislate in this rapidly developing field. However, the possibility of discrimination by employers and insurers against individuals who choose not to engage in such enhancement is a serious threat worthy of legislative intervention. While lawmakers should not prevent individuals from freely pursuing neurocognitive enhancement, they should act to ensure that such enhancement is not coerced. This paper offers one model for such legislation, based upon a proposed US law, the Genetic Information Nondiscrimination Act of 2008, to address precisely this particular pitfall of the impending neuroscience revolution.
Patients’ attitudes towards “do not attempt resuscitation” status
Authors: Gorton A J , Jayanthi N V G , Lepping P , Scriven M W
Published: July 2008

Introduction:

The decision of “do not attempt resuscitation” (DNAR) in the event of cardiopulmonary arrest is usually made when the patients are critically ill and cannot make an informed choice. Although, various professional bodies have published guidelines, little is know about the patients’ own views regarding DNAR discussion.

Aim:

The aim of this study was to determine patients’ attitudes regarding discussing DNAR before they are critically ill.

Methods:

A prospective study was performed in a general out patients department. A questionnaire was distributed to consecutive outpatients along with an explanatory leaflet in the adult outpatient clinic.

Results:

364 patients completed the questionnaire (response rate 77%). 90% of respondents wanted all patients to be asked regarding DNAR decision at some point during a hospital admission. The majority would not find a DNAR discussion distressing. Only 10% would find it upsetting, however, 48% of these still wanted a discussion. 37% of respondents wanted to discuss DNAR decisions on admission; 32% in outpatients; 17% at consent for surgery, 14% when they are critically ill. 87% of respondents would not object to their relatives being involved in making decisions about their resuscitation status. However, only 12% of the subjects in the study had been involved in discussing the resuscitation status of a relative and 21% would not be comfortable to discuss a relative’s resuscitation status. Although 33% of patients preferred their resuscitation status to simply be documented within their clinical notes, 77% wanted it to be more easily accessible.

Conclusions:

This study suggests that contrary to current practice most patients want to discuss their DNAR status prior to becoming critically ill. This includes half of the small number that find it distressing to discuss. Although most patients are comfortable with relatives being involved in discussing DNAR, a significant proportion do not want their relatives to be asked. Furthermore, once a decision has been made, the majority of patients want it to be more accessible than current practice allows.
Not a NICE fallacy: a reply to Dr Quigley
Authors: Claxton K , Culyer A J
Published: July 2008

A repudiation of Muireann Quigley’s argument that the National Institute for Health and Clinical Excellence (NICE) values and assesses the worth of people’s lives; together with an alternative account of what it appears that NICE actually does, why these procedures are not unreasonable and some of the unresolved problems, especially when making interpersonal comparisons of health, which remain for NICE or, indeed, anyone seeking to determine the contents of the benefits bundles of a public health insurance programme such as the NHS. Some other ethically dubious propositions by Dr Quigley are also rejected.
Winter energy requirements of blue grouse
Authors: Pekins Peter J. , Gessaman James A. , Lindzey Frederick G.
Published: July 2008

We measured the effects of temperature (Ta) on the metabolic rate of 6 blue grouse (Dendragapus obscurus) during winter with indirect respiration calorimetry. The standard metabolic rate was 0.812 L O2∙(kg0.734)−1∙h−1 and was 24% higher than that predicted allometrically. The lower critical temperature (Tlc) of fasted grouse was −5 °C; metabolism increased linearly below −5 °C. The heat increment associated with a Douglas-fir (Pseudotsuga menziesii) diet lowered the Tlc by 5 °C From −5 to −20 °C, the metabolism of fasted and fed grouse increased by 30 and 12%, respectively. A positive winter energy balance was predicted for blue grouse from estimates of the field metabolic rate and the consumption and assimilation rates of a Douglas-fir diet.
Uptake and metabolism of histamine by the rat tapeworm Hymenolepis diminuta: an in vitro study
Authors: Yonge Katharine A. , Webb Rodney A.
Published: July 2008

The uptake of histamine by the rat tapeworm Hymenolepis diminuta was examined in intact worms and in worms denuded of tegument. Uptake was by a sodium-independent mechanism and was not inhibited by compounds that inhibit active transport of amines. The uptake of histamine was linear over all concentrations examined, including concentrations to which the worms are exposed in vivo. Q10 was consistent with uptake by simple diffusion. Histamine uptake was inhibited at pH 5.9 but not at higher pH values. The only metabolite of histamine found was imidazole acetic acid. Production of this metabolite was inhibited by heat treatment of the worms and by the presence of known diamine oxidase inhibitors, suggesting the occurrence of diamine oxidase. This enzymatic activity was found in the tissues of the worm. In contrast, H. diminuta did not synthesize histamine from histidine. Collectively the data suggest that histamine in the tissues of H. diminuta is of exogenous origin, entering the tissues by diffusion, where it is metabolized by an endogenous diamine-like oxidase to imidazole acetic acid.
Breeding biology of an insular population of the masked shrew (Sorex cinereus Kerr) in Nova Scotia
Authors: Teferi Taye , Herman T. B. , Stewart D. T.
Published: July 2008

The breeding biology of a high-density population of the masked shrew, Sorex cinereus Kerr, from Bon Portage Island, Nova Scotia, was examined over 2 years. Data were collected on reproductive condition, litter size, age structure, and sex ratio from shrews pitfall-trapped during June–November 1986 and May–November 1987. Breeding activity among overwintered adults declined from spring to fall. Most, but not all, overwintered adults bred. A small proportion of young of the year bred in their year of birth. Among overwintered adults, reproductively active shrews were significantly longer and heavier than nonbreeders. Among young of the year, reproductively active individuals were significantly heavier but not longer than nonbreeders in their age-class. In both years some individuals were still reproductively active in November. The age distribution of the population suggested that recruitment extended beyond the spring and summer pulses typical of shrew populations at this latitude. Based on their age distribution and the presence of late breeders in both years, it is likely that limited reproduction occurs throughout the year in this population. In contrast to some island populations of rodents, there was no indication of reduced reproductive activity in this insular population of insectivores.
Structural organization and histochemistry of the epithelia of the lips and associated structures of a common Indian carp, Cirrhina mrigala
Authors: Agrawal Nalini , Mittal Ajay Kumar
Published: July 2008

In the carp Cirrhina mrigala, the epithelia of the lips and associated structures show significant modifications in relation to the feeding behaviour of the fish and the nature of food that it consumes. The superficial layer of epithelial cells, modified to form characteristic unculi on the ventral side of the upper lip and a conspicuous epithelial cone on the apical side of the horny lower jaw sheath, is keratinized. These specialized structures help the fish to scrape the substrate, serve as a cutting edge, and assist the fish to grasp the food. The epithelia on the dorsal side of the upper lip, the rostral cap, the lower lip, and the folds of skin between the upper lip and the rostral cap and between the lower lip and skin on the ventral side of the head are unkeratinized. The mucous secretions on the surface in these regions serve primarily to protect in various ways. In addition, lubrication provided by mucous secretions in the folds of skin reduces friction during protrusion of the jaws, enabling the fish to manipulate its food swiftly and efficiently. The presence of taste buds in the epithelia in the apical regions of the lips and on the rostral cap is considered an adaptation to assist the fish in searching for suitable food.
The effect of food level on growth rate and frequency of metamorphosis and paedomorphosis in Ambystoma gracile
Authors: Licht Lawrence E.
Published: July 2008

The effect of food level on larval growth response and frequency of metamorphosis and paedomorphosis was examined in Ambystoma gracile from high- and low-elevation populations in British Columbia. Larvae that eventually metamorphosed and those that became paedomorphic did not differ in growth rates when fed equal quantities of food. Body size at metamorphosis did not differ between fast- and slow-growing larvae, but larvae fed high levels of food metamorphosed sooner than those fed less. Food level had no effect on the frequency of metamorphosis and paedomorphosis. Larvae of different sexes did not differ in growth rate or frequency of metamorphosis and paedomorphosis, nor did larvae originating from populations from high and low elevations. Variation in the metamorphic response occurred within and between larvae from separate egg clutches. The findings are discussed in light of current hypotheses on factors influencing alternative life-history patterns in facultatively paedomorphic salamanders.
Genetic differentiation and biogeography of the masked shrew in Atlantic Canada
Authors: Stewart Donald T. , Baker Allan J.
Published: July 2008

The masked shrew (Sorex cinereus) occurs naturally on a number of small to large islands in Atlantic Canada, and 22 individuals were introduced into Newfoundland from New Brunswick in 1958. Genetic variation detected by protein electrophoresis of 34 presumptive gene loci was assayed in five island and three mainland populations from this region to compare rates of differentiation among the populations and to investigate genetic relationships among populations in the context of historical biogeographic events constructed from the geological literature. We found considerable differentiation among populations which can be attributed to different origins for the populations in the post-Wisconsin glacial phase, and to apparently rapid evolution in small isolated populations, especially for the small island of Bon Portage, Nova Scotia. Allele frequencies are more heterogeneous among the island populations and exhibit classic neutral behaviour in that rare allelles are absent and shifts in allele frequency occur to either side of mainland means. There is no correlation of allele frequencies with geographic proximity of populations as might be expected under selectively based clines, or, alternatively, under isolation by distance expected with a diffusive wave of colonization in the region. Instead, the genetic data are compatible with random drift of neutral alleles in populations of various efffective sizes isolated from each other by rising sea levels in the last 20 000 – 5000 years. The considerable divergence that has occurred among the island populations (FST = 0.238) may be indicative of incipient speciation or subspeciation. This subdivision does not appear to be founder-induced but is more likely the product of gradual drift in and interruption of homogenizing gene flow among relict populations that existed during the Pleistocene.
Ultrastructure of the organ of Bellonci in the hypogean isopod Stenasellus virei boui Magniez (Crustacea, Asellota)
Authors: Pitzalis Adriana , Juberthie Christian
Published: July 2008

The ultrastructure of the organ of Bellonci in the hypogean isopod Stenasellus virei boui was investigated. There are two organs located anterodorsally, one on each side of the cephalon. Each organ consists of a wall surrounding a cavity with a central core irregular in shape. The bordering wall contains some glial cells and the inner dendritic segments of 25–28 sensory cells, each one bearing two cilia. Each cilium has a typical 9 + 0 axoneme, a basal body, and a long straight ciliary root that is at a right angle to the basal body; the cilium branches out into tubules that usually contain 1 microtubule, occasionally 2 or more. The ciliary tubules are gathered in three or four long bundles and are not linked to the core. The ciliary connections appear to be both conical and cylindrical. The ultrastructural morphology (polarization of the cilia, spatial arrangement of the bundles and central core) suggests that this organ can record directional stimuli.
Characteristics of northern flying squirrel populations in young second- and old-growth forests in western Oregon
Authors: Rosenberg Daniel K. , Anthony Robert G.
Published: July 2008

We compared density, sex ratio, body mass, and annual recapture rate of northern flying squirrel (Glaucomys sabrinus) populations in second-growth and old-growth Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Cascade Range. Densities averaged 2.0 and 2.3 squirrels/ha in second- and old-growth stands, respectively. Although densities varied between years within stands, average densities were similar between years. Body mass and annual recapture rate were similar between stand–age classes, although a higher proportion of females was recaptured in subsequent years in second-growth than in old-growth stands. Similarly, there was a higher proportion of females than males in second-growth but not in old-growth stands. Squirrel densities were not correlated with habitat characteristics; we concluded that flying squirrels may be habitat generalists, and not a species associated with old-growth stands, as was previously hypothesized. We suggest that studies be carried out with radiotelemetry to more accurately assess the habitat associations of this species.
Evolution of brown fat: its absence in marsupials and monotremes
Authors: Hayward John S. , Lisson Paul A.
Published: July 2008

Species from all extant families of marsupials and monotremes were examined to clarify whether these mammalian subclasses possess brown adipose tissue. To optimize the chance of finding this tissue, special emphasis was given to sampling species adapted to colder regions, species with small adult body size, and individuals at a stage of development equivalent to the newborn stage of placentals (late pouch life in the case of marsupials). Evidence based on gross morphology and light, electron, and fluorescence microscopy failed to show the presence of brown adipose tissue in any marsupial or monotreme. All adipose tissue was typical white fat, including special instances where multilocularity of lipid droplets occurred in association with white adipocyte development or with fat mobilization resulting from nutritional or cold stress. These results, combined with lack of positive identification of brown adipose tissue in birds or other vertebrates, indicate that brown adipose tissue is unique to eutherian (placental) mammals and probably evolved early in the radiation of this subclass. This uniqueness presents the opportunity to suggest a more satisfactory name for the subclass: Thermolipia (from the Greek for "warm fat") or, commonly, thermolipials.
Impact of an experimental wolf reduction on beaver in Papineau-Labelle Reserve, Quebec
Authors: Potvin François , Breton Laurier , Pilon Christian , Macquart Marc
Published: July 2008

From 1983 to 1988 the densities of beaver colonies in traplines from within two blocks were compared. The first block (RB, 275 km2) was included in a larger area where wolves were reduced almost 60% over three winters. The second block (UB, 265 km2) received no wolf-control treatment. Beaver trapping, formerly prohibited, was allowed in 1984 in 5 of 11 trapline units of RB and 5 of 9 units of UB after the first wolf reduction. The density of colonies (0.8/km2) remained stable in UB, even where beaver trapping was allowed. In RB a 20% increase in colonies occurred after 3 years in units not opened to beaver trapping, but the numbers decreased to their former level 2 years after wolf control was terminated. Where wolf reduction and trapping occurred synchronously, colony numbers remained unchanged, but they decreased by 30% following suspension of wolf control. We do not recommend wolf reduction as a management tool when beaver density is high.
In vitro culture and multiplication of Cryptobia catostomi and experimental infection of white sucker (Catostomus commersoni)
Authors: Thomas Philip T. , Woo Patrick T. K.
Published: July 2008

Cryptobia catostomi, a parasitic haemoflagellate of the white sucker (Catostomus commersoni), was cultured in minimum essential medium (MEM) supplemented with Hanks' salts, L-glutamine, and 25% foetal bovine serum (MEM-plus). Parasite numbers were significantly higher in MEM-plus cultures supplemented with white sucker plasma than in unsupplemented cultures. This procedure is useful when large numbers of the parasite are required, e.g., for studies on their nutritional requirements, metabolism, or antigenic nature. Cultures could not be maintained at 10 °C beyond the fourth subculture; this was about 11 months after the primary culture was started. The division process in culture was similar to that reported in fish. The culture forms were infective to white suckers. Parasitaemias in white suckers infected with blood forms increased from 2 to 5 weeks postinfection and stayed relatively constant thereafter. Neither anorexia nor anaemia was evident in infected fish, confirming the nonpathogenicity of C. catostomi to white suckers.
The wing venation and systematics of Lower Permian Diaphanopterodea from the Ural Mountains, Russia (Insecta: Paleoptera)
Authors: Kukalová-Peck Jarmila , Sinichenkova Nina D.
Published: July 2008

Extinct Diaphanopterodea are described from the Lower Permian of Tshekarda, Urals, Russia: Parelmoidae: Uralia n.gen. (Uralia maculata n.sp. and Uralia sharovi n.sp.); Paruraliidae n.fam.: Paruralia n.gen. (Paruralia rohdendorfi n.sp. and Paruralia carpenteri n.sp.). Of all Paleozoic insects, the exceedingly well-preserved specimens of U. maculata have contributed the most important clues to the pterygote ground plans of the head, mouthparts, leg segmentation, thoracic and abdominal pleura, and genitalia.
The "Uniramia" do not exist: the ground plan of the Pterygota as revealed by Permian Diaphanopterodea from Russia (Insecta: Paleodictyopteroidea)
Authors: Kukalová-Peck Jarmila
Published: July 2008

The paleomorphology of extinct Paleozoic Diaphanopterodea (Paleodictyopteroidea: Paleoptera) in exceptionally well-preserved Lower Permian Uralia (Parelmoidea) and Paruralia (Paruraliidae) from Tshekarda in the Ural Mountains, Russia, was used to identify the basic morphological components of the pterygote head, body, and genitalia, as follows: a 6-segmented head with sutures between the somites and between the cephalic terga and epicoxae; antennae 2 with four enlarged basal elements and a flagellum; mandibles (shown as fully homologous to the gnathobase of other arthropods) with a sliding anterior articulation; leglike maxillary palps, labial palps, abdominal leglets, and gonostyli, all starting with prefemur, bearing a fully articulated patella (as in spiders) and ending in double claws; polyramous thoracic legs (i.e., with several outer rami or exites) and a prefemur not associated, as it usually is, with the trochanter; a thoracic pleuron (wall support) formed from a flattened subcoxa; an abdominal pleuron clearly composed of three flattened leg segments: the subcoxa, coxa, and trochanter; and genitalia revealing their derivation from legs bearing coxal and trochanteral endites. It is suggested that the homoeotic mutant ophthalmoptera is a morphologically acceptable indication that the cephalic epicoxa surrounds the eye. The presence of several rami (exites) on the legs of primitive Paleozoic and modern Crustacea, Chelicerata, and Insecta shows that they share a polyramous arthropod leg; "biramy," as well as "uniramy," is always secondary and does not define higher arthropod taxa. The Atelocerata Heymons, 1901 (= Myriapoda + Hexapoda) is a natural taxon. "Uniramia" was a taxon based mainly on an erroneous "ground plan" of the arthropod leg and mandible, and should be completely dropped from use. In marine arthropods, one of the upper exites often convergently develops into a long swimming oar ramus, and the legs become functionally "biramous." A complex aquatic epicoxal oar ramus of the ancestral Atelocerata may be the only appendage suitably preadapted to become a protowing, modifiable by selection for flapping flight. Paleodictyopteroids with sucking rostra (about 50% of Paleozoic entomofauna) are probably the most important selective agent that initiated the change from the Paleozoic plant community into the present plant community.
Late-winter activity patterns of moose (Alces alces gigas) in western Alaska
Authors: Gillingham Michael P. , Klein David R.
Published: July 2008

Activity patterns of free-ranging moose (Alces alces gigas) on the central Seward Peninsula were polyphasic but not highly synchronized among individuals from March through May 1987. Female–calf pairs, however, showed nearly identical activity patterns (92.6% of 2353 five-minute scans). Based on data collected between 06:00 and 24:00, we estimate that moose exhibit ~5 or 6 active bouts per 24-h period. Our direct observations of moose (980 moose-h) showed that moose were active 57.2% of the time from 06:00 to 24:00. Inactive bouts lasted ~2.5 times longer than active bouts. Calves tended to lie for longer [Formula: see text] than adult females (143.1 ± 15.5 min) or males (109.0 ± 17.9 min). Time budgets for moose in late winter were intermediate between values reported in previous studies for moose in midwinter and late spring. Our data showed that moose spend much more time walking (8%) than previously reported. We think this reflects their use of the snow-packed river and gravel bars as movement and feeding corridors. Direct observations of moose showed that many active and inactive bouts were less than 10 min in duration; these bouts are not detected by most telemetric systems. We also present evidence that without predation in winter, ambient conditions (e.g., operative temperature) may cause synchrony in the activity patterns of individual moose in northwestern Alaska.
An audio index for male spruce grouse
Authors: Keppie Daniel M.
Published: July 2008

An audio index was developed for estimating the density of male spruce grouse (Dendragapus canadensis). The index is based on counts of fluttering males heard during hikes at dawn, and is derived from work carried out in New Brunswick and Ontario over a period of 7 years. Densities of males were determined over 6 years; the number of males heard fluttering per hour of hike correlated well with male density (r = 0.91).
Oxygen stores and aerobic metabolism in the leatherback sea turtle
Authors: Lutcavage Molly E. , Bushnell Peter G. , Jones David R.
Published: July 2008

The leatherback sea turtle, Dermochelys coriacea, is a large, deep-diving species that has a blood oxygen carrying capacity twice that of smaller, shallow-diving sea turtles. In this study we measured lung volume (by argon dilution) and blood volume (by dilution of Evans' blue dye) in leatherbacks to estimate partitioning of oxygen stores and their potential contribution to aerobic metabolism during diving. Blood volume (77 mL∙kg−1) was slightly higher, yet lung volume was considerably smaller (64 mL∙kg−1), than in other sea turtles, so that potential oxygen stores were almost equally divided between the lung (12 mL∙kg−1) and the blood and tissues (15 mL∙kg−1). At a body temperature of 32–34 °C and high heart rates (43–48/min), oxygen consumption of beached and netted leatherbacks was 1.1 mL∙min−1∙kg−1. The respiratory quotient exceeded unity, suggesting that the turtles were repaying an oxygen debt incurred in the netting procedure. Estimates of the probable utilization of oxygen stores and possible maximum and minimum oxygen uptakes were used to obtain a range of dive times (5–70 min) that can be supported aerobically.
Ecology and evolution of sympatric sticklebacks (Gasterosteus): evidence for a species-pair in Paxton Lake, Texada Island, British Columbia
Authors: McPhail J. D.
Published: July 2008

Two forms of Gasterosteus coexist in Paxton Lake on Texada Island, British Columbia. One form (benthic) is predominantly a littoral, benthic forager, whereas the other form (limnetic) is an open-water plankton feeder. The benthic form is large (up to 90 mm in standard length), with a stout body, a wide mouth, relatively few short gill rakers, and a greatly reduced number of lateral plates and dorsal spines. The entire pelvic girdle is absent in about 80% of adults. In contrast, the limnetic form is slim bodied, with a narrow mouth, numerous long gill rakers, and normal lateral plates, dorsal spines, and pelvic girdle. In laboratory crosses, Paxton Lake benthic and limnetic sticklebacks breed true and this suggests that they represent separate gene pools rather than a foraging polymorphism. The differences in morphology and allele frequencies between the two forms have remained stable for over two decades (about 20 generations), yet discriminant function analysis indicates that about 1% of the adult sticklebacks in Paxton Lake are hybrids. This estimated level of hybridization has remained constant since 1968. The stable differences in allele frequencies and morphology suggest that there is no gene flow between the two forms. There is, however, some evidence for gene flow in the past, and although the two forms now behave as biological species, they probably retain the capacity to exchange genes. Both the genetic distance between the two forms, estimated from 25 presumptive loci, and the postglacial history of the area suggest that the divergence is recent.
Physiological implications of continuous, prolonged, and deep dives of the southern elephant seal (Mirounga leonina)
Authors: Hindell Mark A. , Slip David J. , Burton Harry R. , Bryden Michael M.
Published: July 2008

The diving behaviour of 14 adult southern elephant seals was investigated using time depth recorders. Each of the seals performed some dives that were longer than its theoretical aerobic dive limit. Forty-four percent of all dives made by post-moult females exceeded the calculated limit compared with 7% of those made by postbreeding females and less than 1% of those made by adult males. The extended dives displayed characteristics that suggested that they were predominantly foraging dives, although some were apparently rest dives. Dives longer than the calculated aerobic limits often occurred in bouts; the longest consisted of 63 consecutive dives and lasted 2 days. Postmoult females performed longer bouts of extended dives than postbreeding females. Extended surface periods (longer than 30 min) were not related to the occurrence of extended dives or bouts of extended dives. The possible physiological mechanisms that permit such prolonged continuous dives are discussed. Southern elephant seals may increase the aerobic capacity of dives by lowering their metabolism to approximately 40% of the resting metabolic rate on long dives. There is substantial interseal variability in the methods used to cope with long dives. Some animals appear to use physiological strategies that allow them to prolong the time available to them at the bottom of a dive, while others use alternative strategies that may limit the time available at the bottom of their dives.
Antennal and palpal sensilla of Forcipomyia (Lasiohelea Kieffer) fairfaxensis Wirth, 1951 (Diptera: Ceratopogonidae) from Algonquin Park, Ontario
Authors: Desser Sherwin S. , Hong Henry
Published: July 2008

The antennal and palpal sensilla of Forcipomyia (Lasiohelea) fairfaxensis, a biting midge that bloodfeeds on frogs in Algonquin Park, Ontario, were examined by light and electron microscopy and compared with those of Culicoides species. A cluster of ~26 bulbous sensilla occurred in a pit on the third palpal segment (an intermediate number of sensilla compared with the mammalophilic and ornithophilic species). Four types of sensilla (chaetica, trichodea, basiconica, and coeloconica) found on the antennae differed in their distribution from, and were significantly higher in number than on either mammalophilic or ornithophilic ceratopogonids.
Do low incubation temperatures yield females in painted turtles?
Authors: Etchberger Cory R. , Ewert Michael A. , Raper Beth A. , Nelson Craig E.
Published: July 2008

The sex of painted turtles (Chrysemys picta) is determined by the incubation temperature of the egg. At high temperatures (> 30 °C), all females are produced, with a transition to all males at most lower temperatures (24–27 °C). However, two of three previous studies have reported that some females also result when incubation temperatures are low (20–22 °C). In this study C. picta eggs were incubated at low temperatures (21.5 and 22.5 °C); however, macroscopic and histological examination of both embryos and hatchlings did not confirm these reports. Thus, C. picta has, at least typically, the pattern of sex determination that is most common among the genera to which it is most closely allied.
Comparative feeding ecology and reproductive performance of ospreys in different habitats of southeastern British Columbia
Authors: Steeger Christoph , Esselink Hans , Ydenberg Ronald C.
Published: July 2008

We compared the general breeding and feeding ecology of ospreys (Pandion haliaetus) in the Creston and Nelson areas of southeastern British Columbia. In the Creston Valley, ospreys nested atop tall trees surrounding a shallow and productive warm-water marsh. Prey species taken by male ospreys included black bullhead (Ictalurus melas), pumpkinseed (Lepomis gibbosus), and yellow perch (Perca flavescens). In contrast, near Nelson, ospreys nested on man-made structures along the narrow West Arm of Kootenay Lake. Osprey prey species in the Nelson area included longnose sucker (Catostomus catostomus), largescale sucker (Catostomus macrocheilus), and mountain whitefish (Prosopium williamsoni). Prey captured at Nelson were larger and contained significantly more energy than at Creston Valley, and hunting from a perch was used for 26% of all captures. All Creston Valley prey were caught by flight hunting. The strike success of foraging ospreys at Nelson was significantly higher than at Creston, and the net yield of flight hunting was 3 times higher. In spite of these differences, the breeding performance of ospreys in the two areas was very similar. Average clutch size was 2.8, brood size at hatching was 2.0, and the average pair fledged 1.4 young. The nest failure rate did not differ between the two areas. Most clutches were initiated in early May, with Nelson-area ospreys laying, on average, 4–7 days later. Egg volumes were smaller at Nelson (66.6 vs. 69.1 cm3). However, the rate at which nestlings gained mass was significantly greater at Nelson. We discuss reasons why the breeding performance varies so little in spite of the great differences in feeding regime.