bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an Apparatus for the Testing of Hydrocephalic Shunts
Authors: Swim Benjamin M. , Reyer Julie A. , Morris Martin J. , Lin Julian J.
Published: March 2008

This abstract summarizes the development of a new apparatus designed to test hydrocephalic shunts. Hydrocephalus is a medical condition most commonly characterized by above-normal intracranial pressure (ICP) that occurs when a patient’s head cannot properly regulate cerebrospinal fluid (CSF) volume in the head. The condition is generally caused by a blockage to flow of CSF in the normal biological pathways. This can result from a birth defect, trauma, or disease. In a hydrocephalic patient, excess fluid builds up in the ventricles resulting in increased mechanical stress and physical deformation of the brain. Untreated, this condition can be quite severe and can lead to brain damage or death. Standard treatment involves implanting an artificial shunt to drain the ventricle and bypass the blockage. The CSF is normally routed to the abdominal cavity. Reducing fluid volume alleviates high ICP and mechanical stress on the brain. Shunting improves the survival rate from 30 to 60 percent for untreated patients to 65 to 95 percent for patients with shunt systems installed [1].
Redundant Wavelet Transform in Biomedical Image Application
Authors: Cui Suxia , Wang Yonghui , Akujuobi Cajetan M.
Published: March 2008

The change of blood vessel is very important in the biomedical research, because creatures, including human beings tempt to adjust themselves to fit for the new environments. For example, if a tumor was found inside a human body and diagnosed as cancer, to get rid of this tumor is important, but to prevent the tumor to reach out to other organs is more crucial. The goal of starving the tumor can be achieved by preventing new blood vessels to grow into it. Another example is the wound healing which can be enhanced by encouraging blood vessels to reach the damaged parts. Both applications focus on the trace of the growing blood vessels. There are several trials on how to trace blood vessels, we can category them into three main approaches: window-based methods, classifier-based methods and tracking-based methods [1]. In this paper, the authors explore the usage of RDWT in this specific area of biomedical image application. Redundant wavelet transform (RDWT) has the property that all of the RDWT coefficients locate at the same spatial location as in the original spatial image, which makes it preferable for feature extraction and signal analysis [2]. With the already successful applications of RDWT in image processing and video coding [3,4], the authors built a new system to segment blood vessels using RDWT coefficient mask.
Biomechanical Simulations of Bioprosthetic Heart Valve Deformations
Authors: Sun Wei , Cao Hengchu , Davidson Jim , Sacks Michael
Published: March 2008

Previous research has suggested that the structural deterioration in porcine bioprosthetic heart valves (BHV) may be correlated with the regions of high tensile and bending stresses acting on the leaflets during opening and closing[1, 2]. Stress concentrations within the cusp can either directly accelerate tissue structural fatigue damage, or initiate calcification by causing structural disintegration, enabling multiple pathways of calcification that can lead to valve failure[3,4]. In the case of bovine pericardial heart valve prostheses, structural failure of the leaflets is rare but calcification has been observed. Although details of the process are unclear, it is generally assumed that the design of the pericardial valve, which gives a stress-reduced state of the leaflets, is likely to provide improved performance in long-term applications.
Evaluation of planting sites common to a southeast Alaska clear-cut. II. Available inoculum of the ectomycorrhizal fungus Cenococcumgeophilum
Authors: Shaw III Charles G. , Sidle Roy C.
Published: March 2008

Three microsites common to clear-cuts logged by the high-lead method in southeast Alaska were sampled to quantify the occurrence and viability of sclerotia of Cenococcumgeophilum Fr. Undisturbed duff had significantly greater numbers of sclerotia per gram or per cubic centimetre of soil than either exposed mineral soil or rotten wood. There were significantly fewer viable sclerotia per cubic centimetre of rotten wood than in either exposed mineral soil or undisturbed duff. Numbers of viable sclerotia that could contact the root plug of a containerized seedling when it was planted into rotten wood, exposed mineral soil, or undisturbed duff were calculated to be 0.7, 6.1, and 7.2, respectively. Expressing abundance of mycorrhizal propagules by soil volume, rather than weight, is more meaningful when microsites with large differences in soil bulk density are compared.
Estimation of individual tree volumes with age and diameter
Authors: Sadiq Riyaz A. , Smith Victor G.
Published: March 2008

Even though invention of high-precision equipment has reduced measurement errors associated with the estimation of heights of standing trees, height estimation is still an expensive and time-consuming operation. At times it is difficult to determine especially in dense forests or in forests located in hilly terrain. The present study advocates a volume–age–diameter function to estimate volumes of individual trees. The technique presented here circumvents measurement of tree heights through the use of age which, however, restricts the application of the function to plantations or forests whose age is predetermined. Analyses with stem-analysis data from red pine (Pinusresinosa Ait.) plantations of southern Ontario indicate that the function estimates tree volumes more accurately than the standard methods commonly used.
Leader and growth characteristics of eastern white pine associated with white pine weevil attack susceptibility
Authors: Wilkinson Ronald C.
Published: March 2008

Seven morphological and growth characteristics of 208 eastern white pine (Pinusstrobus L.) leaders, measured when the trees were 22 years old, along with heights and diameters were examined in relation to susceptibility to white pine weevil (Pissodesstrobi Peck.) attack. Bark thickness, depth of inside and outside resin ducts, and diameters of 1978 leaders were positively and significantly correlated (1% level of probability) with number of successful weevil attacks over the previous 11-year period. Correlations between number of weevil attacks and leader length, and numbers of inside and outside resin ducts were not significant. Tree diameter (17 and 22 years) and early height growth (10 and 17 years) were more strongly correlated with numbers of past weevil attacks than leader characteristics were. Leader morphology and growth rates of the trees were highly correlated. Only 13.1% of the tree to tree variation in numbers of successful weevil attacks, determined by multiple stepwise regression with all leader characteristics plus cortical monoterpene concentrations as independent variables, could be attributed to variation in the combined characteristics. This percentage is much too low to be of immediate value in distinguishing highly susceptible from more resistant trees.
Weibull diameter distributions for mixed stands of western conifers
Authors: Little Susan N.
Published: March 2008

The three-parameter Weibull function met specified standards for goodness of fit as a model for the diameter distributions of mixed stands of western hemlock and Douglas-fir. Weibull distributions estimated by maximum likelihood (MLE) fit 80 of 83 observed diameter distributions at the α = 0.20 level of significance by the Kolmogorov–Smirnov test. Weibull parameter prediction equations were developed by regressing characteristics of 42 stands against MLE of the parameters. The Weibull diameter distributions predicted from stand age, mean diameter, mean height, and trees per acre (1 a = 100 m2) fit 39 of 41 observed distributions in the test group at the α = 0.20 level of significance. These results compared favorably with those found for various forest types by other authors. These prediction equations will prove useful in stand modeling and in updating forest inventories.
Use of the ectomycorrhizal fungus Laccarialaccata in forestry. II. Effects of fertilizer forms and levels on ectomycorrhizal development and growth of container-grown Douglas-fir and ponderosa pine seedlings
Authors: Molina Randy , Chamard John
Published: March 2008

Container-grown Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and ponderosa pine (Pinusponderosa Dougl. ex Laws.) were inoculated with the ectomycorrhizal fungus Laccarialaccata (Scop, ex Fr.) Berk, and Br. and grown under three levels of soluble fertilizer (low, high, and a combination of low changed to high) and full and half strength of a slow-release fertilizer. Ectomycorrhiza development was excellent for both hosts regardless of fertilizer treatment; percent ectomycorrhizal short roots averaged 93.6 for Douglas-fir and 94.5 for ponderosa pine. Inoculation did not affect the size of Douglas-fir but significantly reduced growth of ponderosa pine under low fertility. L. laccata performed well under high-fertility regimes; production of outplantable nursery stock with well-developed ectomycorrhizae was obtained.
Nitrogen accretion, soil fertility, and Douglas-fir nutrition in association with redstem ceanothus
Authors: Binkley Dan , Husted Lynn
Published: March 2008

Nutrient contents of soil and foliage of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) saplings were determined in areas without redstem ceanothus (Ceanothussanguineus Pursh), at the edges of redstem ceanothus patches, and within patches. Tree growth was not examined. Total soil N (0–15 cm depth) was 50–75% greater at the edge of and within redstem patches than in areas without redstem. Assuming soil N was initially similar at all three positions, N accretion was 24–50 kg•ha−1•year−1 for 10 years. Total N accretion in the ecosystem was probably 45–80 kg•ha−1•year−1. Available N index and extractable Ca and Mg were 2–3 times greater at the edges of and within the redstem patches than outside them. Concentrations of N, Ca, and Mg in the Douglas-fir foliage were lowest outside the patches, intermediate at the edges, and highest within the patches. Because needle weight was lower for saplings within patches than for those at the edges, the latter had the greatest foliar nutrient content. Enhancement of site fertility by redstem ceanothus, as well as its benefits to wildlife and slope stability, make it an attractive candidate for mixed plantations with conifers.
Growth characteristics of lodgepole pine associated with the start of mountain pine beetle outbreaks
Authors: Shrimpton D. M. , Thomson A. J.
Published: March 2008

The dynamics of tree and stand growth were studied in six small but expanding mountain pine beetle outbreaks in British Columbia. Stands had exceeded a previously reported hazard threshold of age 80 years by 26 years, and a second frequently used hazard threshold of 20.5 cm mean dbh was exceeded by 37 years. However, stands had exceeded maturity, as defined by the intersection of current annual increment (CAI) and mean annual increment (MAI), by an average of only 17 years. In all cases, the beginnings of the outbreaks were coincident with a period of reduced tree growth. This reduced tree growth was difficult to detect at breast height, with a consequent failure of the periodic growth ratio to indicate susceptibility. Although the stands were past the point of maturity, the dominant and codominant trees continued to add significant wood volume, which could make surveillance for incipient outbreaks and subsequent control actions cost effective.
Assessing locational advantages of markets in terms of delivered cost of wood
Authors: Rose Dietmar W. , Montzka Thomas B. , Bradley Dennis P. , Hoganson Howard M.
Published: March 2008

Procedures are described which estimate the locational advantages of mill sites in terms of wood procurement costs and the relative competition among mills in a region. At the heart of the process a transportation matrix links individual harvestable timber stands to mill locations in the region. The procedures estimate delivered wood cost curves for individual mills or mill sites, and indices that measure the degree of competition for wood among mills. The procedures arc completely automated. They enable planners to examine the impact of different demand scenarios in terms of relative ability of mills to obtain wood.
Cell-penetrating peptides and proteins: new inhibitors of allergic airways diseaseThis review is an invited paper from 2007 ICRH Leadership in Science: a Forum for Trainees and New Investigators.
Authors: Kinyanjui Margaret W. , Fixman Elizabeth D.
Published: March 2008

Cell-penetrating peptides (CPPs) or protein transduction domains (PTDs) are peptides that have the ability to efficiently traverse cellular membranes, either alone or in association with molecular cargo. Several naturally occurring PTDs, including those from HIV TAT and Drosophila antennapedia, have this unique activity. Synthetic CPPs, such as polyarginine, also have the ability to enter cells and transport a variety of cargo. While the precise mechanism(s) of cellular entry for individual CPPs may vary, it is likely that uptake is mediated, at least in part, through endocytosis. Moreover, biological activity of cell-penetrating peptides and proteins has been clearly demonstrated in a number of in vitro and in vivo studies. Recently, cell-penetrating proteins targeting the Ras GTPase and the phospholipid kinase PI3K (phosphoinositide 3-kinase) have been shown to inhibit eosinophil trafficking and survival in vitro. These proteins, as well as CPPs targeting the STAT-6 transcription factor or the T-cell costimulatory molecule CTLA-4 (cytotoxic T lymphocyte-associated antigen-4), have also been tested in animal models of asthma. Data from several groups, including ours, indicate that these molecules inhibit airway eosinophilic inflammation, airway hyperresponsiveness (AHR), and mucus production in experimental allergic airways disease. Thus, CPPs targeting these and other signaling molecules may also effectively inhibit allergic airways disease in humans.
Oral glucose tolerance test reduces arterial baroreflex sensitivity in older adults
Authors: Madden Kenneth M. , Tedder Gale , Lockhart Chris , Meneilly Graydon S.
Published: March 2008

Although postprandial decreases in blood pressure are a common cause of syncope in the older adult population, the postprandial effects of the oral glucose tolerance test on blood pressure and the arterial baroreflex remain poorly characterized in older adults. Therefore, arterial blood pressure and the arterial baroreflex were studied in 19 healthy older adults (mean age 71.7 ± 1.1 years) who were given a standardized oral glucose load (75 g) or an isovolumetric sham drink during 2 separate sessions. All measures were taken for 120 min after treatment. Baroreflex function was assessed by using the spontaneous baroreflex method (baroreflex sensitivity, BRS). Subjects demonstrated a decrease in BRS after oral glucose that was not seen in the placebo session (two-way analysis of variance, p = 0.04). There was no significant change in systolic, mean, or diastolic blood pressure; together with a drop in BRS, this resulted in a significant tachycardia post glucose (two-way analysis of variance, p < 0.001). We conclude that healthy older adults can successfully maintain blood pressure during an oral glucose tolerance test despite a decrease in arterial BRS. Decreased BRS resulted in a tachycardic response to glucose.
Half-logistic time constant: a more reliable lusitropic index than monoexponential time constant regardless of temperature in canine left ventricle
Authors: Mizuno Ju , Matsubara Hiromi , Mohri Satoshi , Shimizu Juichiro , Suzuki Shunsuke , Mikane Takeshi , Araki Junichi , Hanaoka Kazuo , Akins Robert , Morita Shigeho
Published: March 2008

Temperature changes influence cardiac diastolic function. The monoexponential time constant (tauE), which is a conventional lusitropic index of the rate of left ventricular (LV) pressure fall, increases with cooling and decreases with warming. We have proposed that a half-logistic time constant (tauL) is a better lusitropic index than tauE at normothermia. In the present study, we investigated whether tauL can remain a superior measure as temperature varies. The isovolumic relaxation LV pressure curves from the minimum of the first time derivative of LV pressure (dP/dtmin) to the LV end-diastolic pressure were analyzed at 30, 33, 36, 38, and 40 °C in excised, cross-circulated canine hearts. tauL and tauE were evaluated by curve-fitting using the least squares method and applying the half-logistic equation, P(t) = PA/[1 + exp(t/tauL)] + PB, and the monoexponential equation, P(t) = P0exp(–t/tauE) + P∞. Both tauL and tauE increased significantly with decreasing temperature and decreased with increasing temperature. The half-logistic correlation coefficient (r) values were significantly higher than the monoexponential r values at the 5 above-mentioned temperatures. This implies that the superiority of the goodness of the half-logistic fit is not temperature dependent. The half-logistic model characterizes the amplitude and time course of LV pressure fall more reliably than the monoexponential model. Hence, we concluded that tauL is a more useful lusitropic index regardless of temperature.
Effects of amlodipine, diltiazem, and verapamil on the anticonvulsant action of topiramate against maximal electroshock-induced seizures in micePresented in part at the 11th Congress of the European Federation of Neurological Societies, Brussels, Belgium, 25–28 August 2007.
Authors: Luszczki Jarogniew J. , Trojnar Michal K. , Trojnar Marcin P. , Kimber-Trojnar Zaneta , Szostakiewicz Beata , Zadrozniak Anna , Borowicz Kinga K. , Czuczwar Stanislaw J.
Published: March 2008

To assess the effect of 3 calcium channel antagonists (amlodipine, diltiazem, and verapamil) on the anticonvulsant action of topiramate (a new generation antiepileptic drug) in the mouse maximal electroshock seizure (MES) model. Amlodipine (20 mg/kg) significantly enhanced the anticonvulsant activity of topiramate in the MES test in mice, reducing its ED50 value from 54.83 to 33.10 mg/kg (p < 0.05). Similarly, diltiazem (5 and 10 mg/kg) markedly potentiated the antiseizure action of topiramate against MES, lowering its ED50 value from 54.83 to 32.48 mg/kg (p < 0.05) and 28.68 mg/kg (p < 0.01), respectively. In contrast, lower doses of amlodipine (5 and 10 mg/kg) and diltiazem (2.5 mg/kg) and all doses of verapamil (5, 10, and 20 mg/kg) had no significant impact on the antiseizure action of topiramate. Pharmacokinetic verification of the interaction of topiramate with amlodipine and diltiazem revealed that neither amlodipine nor diltiazem affected total brain topiramate concentration in experimental animals, and thus, the observed interactions were concluded to be pharmacodynamic in nature. The favorable combinations of topiramate with amlodipine or diltiazem deserve more attention from a clinical viewpoint because the enhanced antiseizure action of topiramate was not associated with any pharmacokinetic changes in total brain topiramate concentration.
Density-dependent body condition and recruitment in a tropical ungulate
Authors: Gaidet N. , Gaillard J.-M.
Published: March 2008

In tropical areas, annual rainfall and predation have been reported to drive population dynamics of most species of large herbivores studied so far, with little direct empirical evidence for density-dependent responses of life-history traits. We here investigated in a game ranch in Zimbabwe density-dependent responses of body condition and recruitment in an impala ( Aepyceros melampus (Lichtenstein, 1812)) population that underwent an experimental drastic reduction of density within 2 years under similar rainfall and predation pressure. Body condition of all sex and age classes was lower during the high-density year than during the low-density year, suggesting increased competition for restricted resources at high density. In addition, we observed a significant increase in population recruitment (from 0.47 to 0.80 juveniles/female) as population density declined. Our study provides a rare example of a direct density-dependent response of body condition at the individual level in a tropical ungulate species, and indicates that food resource variation controls population dynamics of impala under constant and moderate predation pressure as is commonly reported in temperate populations of large herbivores.
Comment on the second reply by Higdon to the comment by Romero and Kannada on “Genetic analysis of 16th-century whale bones prompts a revision of the impact of Basque whaling on right and bowhead whales in the western North Atlantic”Appears in Can. J. Zool. 86(1): 76–79.
Authors: Romero Aldemaro , Kannada Shelly
Published: March 2008

The second reply by J.W. Higdon (2008. Can. J. Zool. 86: 76–79) criticizes a previously published comment by us of T. Rastogi et al.’s (2004. Can. J. Zool. 82: 1647–1654) paper saying that we presented factual errors, misused key sources, and made a number of omissions. The main objective of our original comment was to show that there had been many other peoples and nations besides the Basques who were engaged in whaling in the North Atlantic for many centuries and, therefore, the Basques could not have been solely responsible for anthropogenic impacts on the populations of large whales in that part of the world. To that end we only sampled some sources to make our point. In this rebuttal, we show that Higdon mischaracterizes our comment as a historical review and that neither he nor B.A. McLeod et al. (2006. Can. J. Zool. 84: 1066–1069) provide any evidence that challenges our fundamental conclusions.
Milk fatty acid signatures indicate both major and minor shifts in the diet of lactating Antarctic fur seals
Authors: Iverson S. J. , Arnould J. P. Y. , Boyd I. L.
Published: March 2008

Fatty acid signature analysis is based on the principle that unique arrays of fatty acids within groups of organisms can be transferred, largely unaltered, up the marine food chain and thus may be an indicator of diet composition. We applied fatty acid signature analysis to milks collected from Antarctic fur seals (Arctocephalus gazella) at South Georgia in 1990–1991, during the perinatal period (N = 19) and subsequently during early (N = 11), mid (N = 11), and late (N = 8) foraging trips. In lactating otariid females, milk fatty acids secreted during the perinatal fast are derived largely from blubber mobilization and thus are influenced by dietary history prior to parturition. Conversely, milk fatty acids secreted during foraging trips are derived primarily from immediate dietary intake. The fatty acid signature of perinatal milks was significantly different from that of all other milks, suggesting differences in the prepartum diet when females are away from the breeding grounds. At the onset of foraging periods, the fatty acid composition of milks' changed dramatically to reflect a diet composed mainly of krill. However, during late foraging periods, milk fatty acids again changed from those of early and mid foraging, and suggested a predominance of teleost fish in the diet. These findings were consistent with independent assessments of diet by faecal analysis and indicate the potential value of fatty acid signature analysis in studying foraging ecology in free-ranging pinnipeds.
Chromosome studies of three families of pelagic heteropod molluscs (Atlantidae, Carinariidae, and Pterotracheidae) from Hawaiian waters
Authors: Thiriot-Quiévreux Catherine , Seapy Roger R.
Published: March 2008

Chromosome number and morphology were studied in gonadal tissue of 11 species of Atlantidae, 2 species of Carinariidae, and 3 species of Pterotracheidae, using an air-drying technique and Giemsa staining. In the Atlantidae the diploid chromosome number was the same in males and females and there were no heteromorphic chromosomes. The diploid chromosome number in nine species of Atlanta was 30 and the majority of chromosome pairs were metacentric and submetacentric. In Protatlanta souleyeti the diploid number was 28, and included five metacentric, six submetacentric, and three subtelocentric chromosome pairs. Oxygyrus keraudreni had a diploid chromosome number of 32, with 10 metacentric and 6 submetacentric chromosome pairs. A striking difference between the Atlantidae and the Carinariidae and Pterotracheidae was the presence of heteromorphic sex chromosomes in the latter two families. Male Pterosoma planum (2n = 32) had simple XY sex chromosomes, but males of Carinaria japonica (2n = 33), Pterotrachea scutata (2n = 33), Pterotrachea hippocampus (2n = 31), and Firoloida desmaresti (2n = 31) showed three heteromorphic chromosomes, suggesting a multiple sex-determining mechanism, X1X2Y. The locations of the female sex chromosomes in the karyotypes of female Pterotrachea hippocampus (2n = 32) and Firoloida desmaresti (2n = 32) were tentatively proposed. Cytogenetic features observed among the three families are supportive of previous interpretations of evolutionary trends in the Heteropoda based on morphology, i.e., that the Atlantidae are the most primitive family and gave rise to the Carinariidae and Pterotracheidae.
Shorebird–prey interactions in South Carolina coastal soft sediments
Authors: Weber Louise M. , Haig Susan M.
Published: March 2008

We investigated the simultaneous influence of benthic prey (primarily insect larvae, oligochaetes, and polychaetes) on spring-migrating shorebirds (Charadriiformes) and shorebirds on prey in brackish managed wetlands of South Carolina. We proposed that positive correlations between shorebird and prey densities and between prey reduction and shorebird density might result in a negative feedback loop. The loop would be characterized by shorebird redistribution over time and equalization of shorebird and prey densities (and biomass) across the site. In support of the feedback loop (i) there were positive correlations between shorebird and prey densities (and biomass) early in migration; (ii) shorebird predation was responsible for declines of 49% in prey density and 50% in prey biomass in a shorebird exclosure experiment, with shorebird density positively correlated with prey decline in open plots; (iii) there was equalization of prey biomass across the site, and relative prey species abundance appeared to become more equal. Contrary to predictions, shorebirds did not redistribute after prey reduction, and patchiness of shorebird and prey densities persisted across the site. This failure was attributed to high prey density, even at the season's end, and high water depths. There were no confounding indirect trophic-level effects.
Annual variation in growth rate and body condition of adders, Vipera berus: effects of food availability and weather
Authors: Lindell Lars Erik
Published: March 2008

The objective of this study was to see if year-to-year variation in size-specific growth rate and body condition of adders, Vipera berus, was correlated with any of four environmental variables: mean summer temperature, number of sunny days during summer, number of days when the temperature was over 15 °C during summer, and vole density as an index of food abundance. Growth rate and body condition were measured during 5 years in two insular populations of adders (at localities A and I) in central Sweden. At locality A, vole density remained constant among years (range 0.86–3.00/ha), whereas at locality I it changed significantly (0.67–22.67/ha). The two localities were approximately 2 km apart and therefore experienced the same weather conditions. At locality A, growth rates (after sex and snout–vent length were controlled for) remained stable, whereas at locality I they varied significantly among years and showed a significant positive correlation with yearly estimates of vole density. I conclude that the growth rate was affected positively by food abundance, but less so by weather. Body condition of male adders (females were excluded because the sample size was small) varied significantly among years in both populations. At locality A, body condition was positively correlated with number of sunny days, whereas at locality I, where vole density changed over the years, body condition was positively correlated with both vole density and number of sunny days. This suggests that both food abundance and weather may be important in determining body condition.
The effect of water surface tension on feather wettability in aquatic birds
Authors: Stephenson Richard , Andrews Catherine A.
Published: March 2008

Birds are dependent upon an insulating layer of air within the plumage for effective thermoregulation. The feathers of aquatic birds must therefore be highly water repellent to prevent the displacement of the air layer. This study investigated the effects of hydrostatic pressure, which is related to body mass and behaviour, and water surface tension on the wettability of adult contour feathers of lesser scaup, Aythya affinis, canvasbacks, A. valisineria, and Canada geese, Branta canadensis minima. Penetration pressure (Pp) of pure water (surface tension 72 mN∙m−1) was 1690 ± 128, 2199 ± 173, and 2096 ± 115 N∙m−2in lesser scaup, canvasbacks, and Canada geese, respectively. This was approximately three times the pressure actually exerted by the birds floating on water and approximately twice the maximum pressure exerted in partially submerged birds. Ppvaried as a nonlinear function of water surface tension. It is concluded that these species of waterfowl will be instantly wetted if water surface tension is reduced to < 40 mN∙m−1, and will be wetted during normal activities at surface tensions below 50 mN∙m−1.
Predation-mediated bird nest diversity: an experimental test
Authors: Marini Miguel Ângelo
Published: March 2008

Differences in nesting characteristics among species of a bird community may increase the mean reproductive success of all species by decreasing mean predation levels on nests (the predation/diversity hypothesis). I tested this hypothesis by (i) manipulating nest-type richness using natural translocated nests, and (ii) correlating predation levels on artificial nests with understory bird richness. I translocated abandoned natural nests (158 nests in 1992 and 199 nests in 1993) of five species of passerines to four (in 1992) and five (in 1993) 1.5 km long transects (ravines) in two-species or five-species assemblages. Experiments conducted in hardwood forests of southern Illinois, U.S.A., during two breeding seasons (1992 and 1993) showed significantly higher predation levels in low than high nest richness sites in 1992 and 1993, and in overall predation during both years. Predation levels, however, varied considerably within richness treatments. If high site-to-site variability in nest predation is not due to stochastic noise, nesting traits may be selected in opposite directions and strengths in different parts of a species' habitat or range. The nest predation/diversity hypothesis was supported at the landscape level but not at the local (ravine) level, stressing the importance of predation as a process structuring bird communities at a large spatial scale. The consequences of this high variation in nest-predation levels on populations, communities, and ecological processes should be well understood before conclusions are drawn.
HAWKING RADIATION VIA TUNNELING FROM GENERAL STATIC BLACK HOLES
Authors: LIU CHENG-ZHOU , ZHAO ZHENG
Published: March 2008

Hawking radiation viewed as a semiclassical tunneling process of particles from the event horizon of general static black holes is investigated by taking the back-reaction of the emitted particles into account. In a general static spacetime, the emission rates of massless, massive and massive charged particles are computed respectively and the tunneling probabilities are obtained. Our results show that when energy and charge conservation are incorporated into the radiation process, the emission rate of the tunneling particles is related to changes of the Bekenstein-Hawking entropies of the black hole before and after the emission, thus it is consistent with an underlying unitary theory. The present results are obtained in a general way, no matter what the special static metric function is, and hence a generalization for the results found in the literature is given. Some remarks on the tunneling method are presented.
CANONICAL AND LIE-ALGEBRAIC TWIST DEFORMATIONS OF GALILEI ALGEBRA
Authors: DASZKIEWICZ MARCIN
Published: March 2008

We describe various nonrelativistic contractions of two classes of twisted Poincaré algebra: canonical one (θμν-deformation) and the one leading to Lie-algebraic models of noncommutative spacetimes. The cases of contraction-independent and contraction-dependent twist parameters are considered. We obtain five models of noncommutative nonrelativistic spacetimes, in particular, two new Lie-algebraic nonrelativistic deformations of spacetime, respectively, with quantum time/classical space and with quantum space/classical time.
A SURVEY OF DARK MATTER DIRECT DETECTION SEARCHES AND TECHNIQUES AT THE BEGINNING OF THE 21ST CENTURY
Authors: SAAB TAREK
Published: March 2008

It is now well established and accepted that roughly 25% of the total mass-energy density of the Universe is in the form of non-relativistic particles. That these particles, referred to as Dark Matter, have remained a mystery has served as motivation for the design and implementation of increasingly ingenious and far reaching experiments in an attempt to identify and understand them. This paper will review various ongoing Dark Matter searches with focus on the variety of techniques and implementation used to both detect the rare Dark Matter interactions as well as reject the vast number of background events.
ETERNALLY INFLATING COSMOLOGIES FROM INTERSECTING SPACELIKE BRANES
Authors: MOCHIZUKI RIUJI
Published: March 2008

Intersecting spacelike braneworld cosmologies are investigated. The time axis is set on the scale parameter of extra space, which may include more than one timelike metric. We obtain the eternally inflating (i.e. undergoing late-time inflation) Robertson–Walker spacetime and extra space with a constant scale factor. In the case of multibrane solutions, some dimensions are static or shrink. The fact that the largest supersymmetry algebra contains 32 supercharges in four dimensions imposes a restriction on the geometry of extra space.
TWO PHOTON DECAYS OF PION IN BETHE–SALPETER FRAMEWORK WITH GENERALIZED STRUCTURE OF HADRON-QUARK VERTEX
Authors: BHATNAGAR SHASHANK
Published: March 2008

Two photon decays of pion are studied in the framework of the Bethe–Salpeter equation under Covariant Instantaneous Ansatz where the structure of hadron-quark vertex function Γ is generalized to include various Dirac covariants (other than γ5) from their complete set. These covariants are incorporated in accordance with a power counting rule (which was recently employed to calculate leptonic decays constants of pseudoscalar mesons and vector mesons) order by order in powers of the inverse of the meson mass. Pion-photon coupling constant Fπ is calculated with the incorporation of leading order covariants.
DOUBLE BETA DECAY RATES AS TEST OF THE TIME VARIATION OF FUNDAMENTAL CONSTANTS
Authors: CIVITARESE O. , LANDAU S. J. , MOSQUERA M. E.
Published: March 2008

We study the effect of the variation of fundamental constants, extracted from cosmological models, upon double beta decay rates. It is found that, by assuming the variations of the fundamental constants with time, one may obtain corrections to the calculated values of the double beta decay rates, but only at earlier times. This effect is notorious for the case of a power-law time dependence of the fine structure constant α and of the Fermi constant GF. However, since these models do not predict any effect on today's decay rates, it is concluded that no significant new information may be extracted about them from current values of double beta decay observables.
A GENERAL INFORMATION THEORETICAL PROOF FOR THE SECOND LAW OF THERMODYNAMICS
Authors: ZHANG QI-REN
Published: March 2008

We show that the conservation and the non-additivity of information, together with the additivity of entropy makes entropy increase in an isolated system. The collapse of the entangled quantum state offers an example of the information non-additivity. Nevertheless, the later is also true in other fields, in which the interaction information is important. Examples are classical statistical mechanics, social statistics and financial processes. The second law of thermodynamics is thus proven in its most general form. It is exactly true, not only in quantum and classical physics but also in other processes in which the information is conservative and non-additive.
SHAPE PHASE TRANSITIONS AND POSSIBLE E(5) SYMMETRY NUCLEI FOR Ti ISOTOPES
Authors: GUO JIAN YOU , FANG XIANG ZHENG , SHENG ZONG QIANG
Published: March 2008

Relativistic mean field theory is used to produce potential energy surfaces (PESs) for Ti isotopes. The relatively flat PESs suggest that 48, 52, 60 Ti , being on the way from vibrations to γ-unstable behavior, are the possible examples with the transitional dynamical symmetry E(5). Especially for 48 Ti , PES shows that it is a better candidate with E(5) symmetry. These conclusions are supported by the experimental data via the observed ratios of excitation energies.
PRODUCTION OF FISSION-LIKE EVENTS AFTER COMPLETE AND/OR INCOMPLETE FUSION OF16OWITH159TbAND169TmATE/A≈MeV
Authors: SINGH PUSHPENDRA P. , SINGH B. P. , SHARMA BHAVNA , UNNATI  , SHARMA MANOJ K. , PRASAD R. , KUMAR RAKESH , BHARDWAJ H. D.
Published: March 2008

With a view to study heavy-ion induced fission after complete and/or incomplete fusion reactions, experiments have been performed at the Inter-University Accelerator Center (IUAC), New Delhi, India. The production cross-sections for more than 40 fission-like events (25 ≤ Z ≤ 45) produced in16O +159Tb and16O +169Tm systems, respectively, at E/A = 5.6 and 5.9 MeV have been measured using the recoil-catcher technique followed by off-line γ-spectroscopy. The analysis of the data indicates that fission is one of the competing modes of de-excitation of excited composite system formed via complete and/or incomplete fusion processes, where the evaporation of light nuclear particle(s) are more likely to be expected. Attempts have also been made to study isotopic yield distributions of Yttrium (83, 84m, 85, 87mY ) and Strontium (80, 81, 83, 85mSr ) isotopes in16O +159Tb system, and Indium (105, 107, 108, 110In ) and Technetium (99m, 101, 104, 105Tc ) isotopes in16O +169Tm system. The statistical analysis of the isotopic yield distribution has also been carried out to determine the most probable values of mass and charge of fission-like events in two systems.
A MATHEMATICAL MODEL FOR PREDATION ON BATESIAN MIMICS
Authors: TSOULARIS A.
Published: March 2008

In this paper, a mathematical model of random encounters between a predator and two types of prey is presented. One type of prey (model) is noxious to the predator whilst the other is palatable (mimic). The mimics resemble the models in appearance so as to derive some protection from the predator who must avoid the unpalatable models. The populations of both mimics and models are assumed to grow logistically. The effect of learning and population growth on prey attacks is examined via simulations.
DEPENDENCE OF THE INDIVIDUAL GROWTH PROCESS UPON ALLOMETRIC SCALING EXPONENTS AND OTHER PARAMETERS
Authors: BISWAS D. , DAS S. K. , ROY S.
Published: March 2008

In the present study, the individual growth process of an organism has been shown with the help of a mathematical model. The surplus energy production rate, i.e. intake rate minus metabolic cost, plays a crucial role in controlling the growth rate. Considering the existence of an optimum mass, which maximizes the surplus energy, it has been found that the scaling exponent for the metabolic cost has to be greater than the exponent for the intake rate. On the basis of the consideration that the system always generates some surplus energy, a relationship among the empirical constants has been established. The growth is found to continue with an ever decreasing rate. When the system attains its optimum mass, the growth rate is found to be the maximum. The mass variation with time has been graphically shown using the expression obtained by solving a differential equation involving surplus energy. Using figures, the dependence of mass variation upon various scaling parameters, has been thoroughly discussed. As mass increases, the surplus energy production rate per unit mass is found to decrease and this may be the probable reason for the smaller number of organisms with larger mass. As the scaling exponent regarding intake increases, the maximum attainable mass increases along with an increase in the time required for its attainment.
CLONING OF HUMAN INTERLEUKIN-10 GENE AND TRANSGENE EXPRESSION IN RABBIT SYNOVIAL CELLSIN VITRO
Authors: Liu Xiangping , Wang Haibo , Yang Kun , Sui Aihua , Wang Yanming , Yu Guangjie , Lu Zhenhua , Wang Jibo
Published: March 2008

In this work, the full-length open reading frame of the human interleukin-10 (hIL-10) gene was amplified through reverse transcription–polymerase chain reaction (RT-PCR), and then PCR products were inserted into pcDNA4/HisMax to construct an eukaryotic expression vector. After optimization by green fluorescent protein (GFP), recombinant hIL-10 genes were transfected and expressed in rabbit synovial cells compounded with liposome in vitro. In cell culture supernatant, rhIL-10 was detected using enzyme-linked immunosorbent assay (ELISA) at time intervals of 12 hours, 24 hours, 48 hours, 72 hours, 7 days, and 14 days. After 12 hours of transfection, ELISA showed that transgene expression of hIL-10 in rabbit synovial cells was elevated; at 72 hours, hIL-10 expression reached its peak value; and then it declined gradually until 7 days, compared with the control. After 14 days, transgene expression ceased. Gene cloning of hIL-10 and its transgene expression in synovial cells therefore gives a basis for the gene therapy of rheumatoid arthritis.
Ellipsis Sites as Definite Descriptions
Authors: Elbourne Paul
Published: March 2008

This article analyzes three phenomena that are troublesome for some theories of ellipsis: the existence of sloppy readings when the relevant pronouns cannot possibly be bound; cases where the antecedent of ellipsis does itself contain an ellipsis site, but in resolving the larger ellipsis the interpretation understood at the ellipsis site in the antecedent is not used; and cases where an ellipsis site draws upon material from two or more separate antecedents. These cases are accounted for by an analysis of silent VPs and NPs that makes them into higher-order definite descriptions that can be bound into.
On the Mental Representation of Arabic Roots
Authors: Idrissi Ali , Prunet Jean-François , Béland Renée
Published: March 2008

In Prunet, Béland, and Idrissi 2000, we presented evidence from an aphasic subject that argued for the morphemic status of Arabic consonantal roots. We predicted that inaudible glides in weak roots should resurface in metathesis and template selection errors, but at the time the relevant data were unattested. Here, we present such data, obtained from a new series of experiments with the same aphasic subject. Arabic hypocoristic formation offers another case of glide resurfacing. Both sources of data confirm that Arabic consonantal roots are abstract morphemic units rather than surface phonetic units.
Free Relatives in Croatian: An Argument for the Comp Account
Authors: Gračanin-Yuksek Martina
Published: March 2008

The article argues for the Comp account (e.g., Groos and Van Riemsdijk 1981) over the head account (e.g., Bresnan and Grimshaw 1978) of free relatives (FRs), on the basis of several converging arguments from Croatian. Evidence from reconstruction effects shows that the wh-phrase introducing a free relative (WHFR) originates inside the relative clause and wh-moves to its surface position. In addition, arguments from clitic placement show that the derived position of the WHFR is no higher than Spec,CP of the FR.
The Vertical Profile of Liquid and Ice Water Content in Midlatitude Mixed-Phase Altocumulus Clouds
Authors: Carey Lawrence D. , Niu Jianguo , Yang Ping , Kankiewicz J. Adam , Larson Vincent E. , Haar Thomas H. Vonder
Published: March 2008

The microphysical properties of mixed-phase altocumulus clouds are investigated using in situ airborne measurements acquired during the ninth Cloud Layer Experiment (CLEX-9) over a midlatitude location. Approximately ⅔ of the sampled profiles are supercooled liquid–topped altocumulus clouds characterized by mixed-phase conditions. The coexistence of measurable liquid water droplets and ice crystals begins at or within tens of meters of cloud top and extends down to cloud base. Ice virga is found below cloud base. Peak liquid water contents occur at or near cloud top while peak ice water contents occur in the lower half of the cloud or in virga. The estimation of ice water content from particle size data requires that an assumption be made regarding the particle mass–dimensional relation, resulting in potential error on the order of tens of percent. The highest proportion of liquid is typically found in the coldest (top) part of the cloud profile. This feature of the microphysical structure for the midlatitude mixed-phase altocumulus clouds is similar to that reported for mixed-phase clouds over the Arctic region. The results obtained for limited cases of midlatitude mixed-phase clouds observed during CLEX-9 may have an implication for the study of mixed-phase cloud microphysics, satellite remote sensing applications, and the parameterization of mixed-phase cloud radiative properties in climate models.
Estimation of Gravity Wave Momentum Flux and Phase Speeds from Quasi-Lagrangian Stratospheric Balloon Flights. Part II: Results from the Vorcore Campaign in Antarctica
Authors: Hertzog Albert , Boccara Gillian , Vincent Robert A. , Vial François , Cocquerez Philippe
Published: March 2008

The stratospheric gravity wave field in the Southern Hemisphere is investigated by analyzing observations collected by 27 long-duration balloons that flew between September 2005 and February 2006 over Antarctica and the Southern Ocean. The analysis is based on the methods introduced by Boccara et al. in a companion paper. Special attention is given to deriving information useful to gravity wave drag parameterizations employed in atmospheric general circulation models. The balloon dataset is used to map the geographic variability of gravity wave momentum fluxes in the lower stratosphere. This flux distribution is found to be very heterogeneous with the largest time-averaged value (28 mPa) observed above the Antarctic Peninsula. This value exceeds by a factor of ∼10 the overall mean momentum flux measured during the balloon campaign. Zonal momentum fluxes were predominantly westward, whereas meridional momentum fluxes were equally northward and southward. A local enhancement of southward flux is nevertheless observed above Adélie Land and is attributed to waves generated by katabatic winds, for which the signature is otherwise rather small in the balloon observations. When zonal averages are performed, oceanic momentum fluxes are found to be of similar magnitude to continental values (2.5–3 mPa), stressing the importance of nonorographic gravity waves over oceans. Last, gravity wave intermittency is investigated. Mountain waves appear to be significantly more sporadic than waves observed above the ocean.