bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recurrent evolution of life history ecotypes in sockeye salmon: implications for conservation and future evolution
Authors: Wood Chris C. , Bickham John W. , John Nelson R. , Foote Chris J. , Patton John C. 
Published: April 2008

AbstractWe examine the evolutionary history and speculate about the evolutionary future of three basic life history ecotypes that contribute to the biocomplexity of sockeye salmon (Oncorhynchus nerka). The ‘recurrent evolution’ (RE) hypothesis claims that the sea/river ecotype is ancestral, a ‘straying’ form with poorly differentiated (meta)population structure, and that highly structured populations of lake‐type sockeye and kokanee have evolved repeatedly in parallel adaptive radiations between recurrent glaciations of the Pleistocene Epoch. Basic premises of this hypothesis are consistent with new, independent evidence from recent surveys of genetic variation in mitochondrial and microsatellite DNA: (1) sockeye salmon are most closely related to pink (O. gorbuscha) and chum (O. keta) salmon with sea‐type life histories; (2) the sockeye life history ecotypes exist as polyphyletic lineages within large drainages and geographic regions; (3) the sea/river ecotype exhibits less genetic differentiation among populations than the lake or kokanee ecotypes both within and among drainages; and (4) genetic diversity is typically higher in the sea/river ecotype than in the lake and kokanee ecotypes. Anthropogenic modification of estuarine habitat and intensive coastal fisheries have likely reduced and fragmented historic metapopulations of the sea/river ecotype, particularly in southern areas. In contrast, the kokanee ecotype appears to be favoured by marine fisheries and predicted changes in climate.
Changes in selection and evolutionary responses in migratory brown trout following the construction of a fish ladder
Authors: Haugen Thrond Oddvar , Aass Per , Stenseth Nils Christian , Vøllestad Leif Asbjørn 
Published: April 2008

AbstractBrown trout (Salmo trutta) are extensively harvested and its habitat highly influenced by human encroachments. Using a 40‐year time series of mark–recapture data we estimate vital rates for a piscivorous trout population. This population spawns upstream of a waterfall, which historically acted as a migration barrier for smaller trout. In 1966, the waterfall was dammed and a fish ladder constructed. All fish ascending the fish ladder were individually tagged and measured for a variety of traits. The fish ladder overall favoured access to upstream spawning areas for middle‐sized trout, resulting in stabilizing selection acting on size at spawning. Over time, natural and fishing mortality have varied, with fishing mortality generally decreasing and natural mortality increasing. The average and, particularly, variance in size‐at‐first‐spawning, and growth rates during the first years of lake residence have all decreased over the 1966–2003 period. These changes are all consistent with a shift from directional to stabilizing selection on age and size at spawning. Estimated rates of phenotypic change are relatively high, in particular for size at first spawning, adding further support for the growing notion that human interference may lead to rapid life‐history trait evolution.
Microsatellite loci isolated from the tropical tree Hymenaea courbaril L. (Fabaceae)
Authors: BUONAMICI ANNA , CAVERS STEPHEN , VENDRAMIN G. G. 
Published: April 2008

AbstractWe developed 11 microsatellite markers for Hymenaea courbaril for the purpose of studying spatial genetic structure and gene flow. The microsatellite loci were screened in 44 trees from two populations. All loci were polymorphic, exhibiting between two and 16 alleles, and levels of expected heterozygosity from 0.174 to 0.909. Departures from Hardy–Weinberg equilibrium were detected for all loci in one population. The estimated null allele frequency is low or moderate. No locus combinations exhibited linkage disequilibrium.
Isolation and characterization of polymorphic microsatellite markers from Asian malaria mosquito Anopheles sinensis (Diptera: Culicidae)
Authors: MA YAJUN , FAN YONG 
Published: April 2008

AbstractMicrosatellite‐containing region were isolated and characterized in Anopheles sinensis, a primary vector of malaria parasites in Asia. An enrichment protocol yielded 252 microsatellite sequences. We designed primers to amplify 20 unique microsatellites, 14 of which amplify cleanly and were polymorphic. A survey of 24 individuals showed that 12 loci are highly variable with the number of alleles ranging from two to 11, and expected heterozygosity ranging from 0.116 to 0.903. These markers will be useful for population genetic studies and genome mapping in A. sinensis.
Polymorphic tetranucleotide microsatellites for Cope's giant salamander (Dicamptodon copei) and Pacific giant salamander (Dicamptodon tenebrosus)
Authors: STEELE C. A , BAUMSTEIGER J , STORFER A 
Published: April 2008

AbstractWe present primers and amplification conditions for 15 microsatellite loci developed for the Cope's giant salamander (Dicamptodon copei), 14 of which are tetranucleotide repeats. Cross‐species amplification revealed 10 of these loci to also be polymorphic in the Pacific giant salamander (Dicamptodon tenebrosus). Several loci produced nonoverlapping allelic ranges between the two species and may be useful in species identification. These polymorphic microsatellite loci are potentially useful for future studies of population genetics in dicamptodontid salamanders.
Timeline and distribution of melanocyte precursors in the mouse heart
Authors: Brito Flavia Carneiro , Kos Lidia 
Published: April 2008

SummaryApart from the well‐studied melanocytes of the skin, eye and inner ear, another population has recently been described in the heart. In this study, we tracked cardiac melanoblasts using in situ hybridization with a dopachrome tautomerase (Dct) probe and Dct‐LacZ transgenic mice. Large numbers of melanoblasts were found in the atrioventricular (AV) endocardial cushions at embryonic day (E) 14.5 and persisted in the AV valves into adulthood. The earliest time Dct‐LacZ‐positive cells were observed in the AV endocardial cushions was E12.5. Prior to that, between E10.5 and E11.5, small numbers of melanoblasts traveled between the post‐otic area and third somite along the anterior and common cardinal veins and branchial arch arteries with other neural crest cells expressing CRABPI. Cardiac melanocytes were not found in the spotting mutants Ednrbs‐l/s‐l and Kitw‐v/w‐v, while large numbers were observed in transgenic mice that overexpress endothelin 3. These results indicate that cardiac melanocytes depend on the same signaling molecules known to be required for proper skin melanocyte development and may originate from the same precursor population. Cardiac melanocytes were not found in zebrafish or frog but were present in quail suggesting an association between cardiac melanocytes and four‐chambered hearts.
Piezoresistive Stress Sensors for Structural Analysis of Electronic
Packages
Authors: Bittle D. A. , Suhling J. C. , Beaty R. E. , Jaeger R. C. , Johnson R. W. 
Published: April 2008

Abstract
Structural reliability of electronic packages has become an increasing concern for a variety of reasons including the advent of higher integrated circuit densities, power density levels, and operating temperatures. A powerful method for experimental evaluation of die stress distributions is the use of test chips incorporating integral piezoresistive sensors. In this paper, the theory of conduction in piezoresistive materials is reviewed and the basic equations applicable to the design of stress sensors on test chips are presented. General expressions are obtained for the stress-induced resistance changes which occur in arbitrarily oriented one-dimensional filamentary conductors fabricated out of crystals with cubic symmetry and diamond lattice structure. These relations are then applied to obtain basic results for stressed in-plane resistors fabricated into the surface of (100) and (111) oriented silicon wafers. Sensor rosettes developed by previous researchers for each of these wafer orientations are reviewed and more powerful rosettes are presented along with the equations needed for their successful application. In particular, a new sensor rosette fabricated on (111) silicon is presented which can measure the complete three-dimensional stress state at points on the surface of a die
Stress Analysis of the Vertical Interconnect for Three-Dimensional
Packaging
Authors: Zouari K. , Lee Y. C. 
Published: April 2008

Abstract
Three-dimensional (3-D) packaging is critical to developing supercompact electronic systems. Its representative configuration consists of several circuit packs connected by pressure sensitive vertical interconnects. The sensitive characteristics of the interconnects demand a uniform distribution of acceptable pressure levels. Solutions to analyze and generate such a distribution are derived for a multilayer configuration under an isothermal assembly condition. They are proved to be insensitive to the unknown interface conditions, and applied to study 1) a five-layer model representing a surface mount assembly and a basic building block for 3-D packaging and 2) multilayer models representing a complete system. A uniform pressure distribution may result from 1) thick metal loading plates with a high modulus, 2) thick polymer interconnects with a low modulus, 3) short loading distances, and 4) addition of more layers. The last factor informs designers a good surface mount fixture design can be readily applied to 3-D packaged systems.
Experimental Modal Analysis and Dynamic Response Prediction of PC
Boards With Surface Mount Electronic Components
Authors: Wong Tin-Lup , Stevens Karl K. , Wang Gang 
Published: April 2008

Abstract
Use of modal testing and structural dynamic modification techniques for prediction of the modal parameters of a PC board with a surface-mount component is described. Experimentally determined natural frequencies and mode shapes of a PC board with and without an added component are presented. Several simple dynamic models of the component are evaluated. Results obtained indicate that the component can sometimes be modeled as a point mass.
A Probabilistic Approach for Predicting Thermal Fatigue Life of Wire
Bonding in Microelectronics
Authors: Hu Jun Ming , Pecht Michael , Dasgupta Abhijit 
Published: April 2008

Abstract
Wire bond connections are susceptible to fatigue failure as a result of various thermo-mechanical damage mechanisms during the component operation life. Because of uncertainties arising from the random nature of temperature fluctuations, the assembly of wirebonds, and fatigue properties of bonding materials, a probabilistic analysis and reliability estimation are appropriate. This paper presents such an approach for predicting thermal fatigue life and reliability of wire bonds in electronic packages. To determine the behavior of wire bonds under thermal cycles, the stress amplitude due to the temperature fluctuation in each fatigue failure mechanism is derived based on stress analysis models, the uncertainties involved in stress determination and life prediction are analyzed, and a life prediction equation is proposed. Examples illustrating the application of the approach are discussed.
Temperature Mapping of Localized Hot Spots on Microelectronic Chip
Surfaces
Authors: Heng S. , Black W. Z. 
Published: April 2008

Abstract
This paper describes the use of digital image processing in conjunction with an infrared imaging apparatus to locate and quantify “micro” hot spot temperatures on the surface of energized microelectronic chips. Briefly, the temperature mapping/processing procedure creates emissivity maps for the surface of the chip at different isothermal conditions. The emissivity map images are digitized and stored as a 512 × 512 pixel array, of which 400 lines contain IR information. Apparent temperature measurements are then collected with the chip energized in its normal operating environment. These apparent temperature data are digitized and stored as a 512 × 512 integer array using the same format as the digitized emissivity data. Before correcting for emissivity variations, the apparent temperature images are rectified using digital image processing to precisely overlay the spatial coordinates of the emissivity map. Finally, actual temperature maps are obtained by correcting the apparent temperature data for the local emissivity variations and background reflections. The computer driven measurement technique has been applied to the task of measuring localized temperatures on areas as small as 30 μm on the surface of an energized chip to an accuracy of ±1°C once the surface emissivity is accurately known. The infrared equipment, image processing hardware and supporting software are used to measure the temperature distribution on the surface of a 4.7 mm × 4.7 mm energized chip. IR measured temperatures at isolated locations on the chip are compared with results obtained by the resistance-temperature technique. Since the resistance-temperature technique provides an area-averaged temperature for the energized region, the result obtained from the high resolution IR measurements yields higher localized temperatures. Results are presented for peak surface temperatures up to 100°C and maximum heat flux values of 7.9x106 W/m2. A separate set of infrared measurements are used to predict the influence of surface emissivity on the accuracy of the temperature measurements.
Natural Convection Cooling of a Horizontally Oriented Component Board
Mounted in a Low-Aspect-Ratio Enclosure
Authors: Krane R. J. , Phillips T. J. 
Published: April 2008

Abstract
This investigation consisted of an experimental study of the natural convection heat transfer from a square, horizontally oriented electronic component board mounted in a low-aspect-ratio enclosure with a square planform. The component board was simulated by an upward-facing constant heat flux surface. A variety of experiments were performed to determine the effects of systematically varying the enclosure geometry on the maximum surface temperature on the board for two values of the modified Rayleigh number (heater power setting).
Optimal Thermal Design of Forced Convection Heat
Sinks-Analytical
Authors: Knight R. W. , Goodling J. S. , Hall D. J. 
Published: April 2008

Abstract
For fully developed flow in closed finned channels used to augment heat transfer, there exists an optimal geometrical design of the size and number of cooling channels. In this paper, the problem is generalized with a statement of dimensionless thermal resistance in terms of • the number of channels • a fin to channel thickness ratio • the length to width (planar dimensions) ratio of the heat source, and • a specified fin efficiency or fin length • a fluid to fin thermal conductivity ratio • the Prandtl Number of the coolant • a dimensionless pressure term, which incorporates the maximum allowable pressure drop through the cooling channels or alternatively, • a dimensionless work rate term, which incorporates the maximum allowable coolant pumping power required, An optimization scheme is described and used for comparison with two previously published cases wherein both designs were restricted to a fixed fin to channel thickness ratio and laminar flow; one by Goldberg (1984) using air and copper and a second one only by Tuckerman and Pease (1981) for water-cooled Silicon wafers. Results from the present optimization scheme show that upon reexamination of the first study by Goldberg, significant reduction of thermal resistance can be obtained by using fin/channel dimensions other than unity. A similar reduction is found in the second instance (Tuckerman and Pease) with the relaxation of the laminar limitation.
Analysis of Transient State Temperature Distribution in the Thyristor
Packaging
Authors: Skorek A. , Jordan A. J. , Rajagopalan V. 
Published: April 2008

Abstract
Transient state temperature distribution in a power electronics module comprising two thyristors was computed using a finite element method (FEM). An optimal positioning of one of the thyristors with respect to another was obtained based on the minimization of two norms ‖T‖2 and ‖Tt‖∞. The results obtained from the simulation are compared with those measured using thermocouple techniques; the agreement between these results is found to be good.
MORSE POSITION OF KNOTS AND CLOSED INCOMPRESSIBLE SURFACES
Authors: OZAWA MAKOTO 
Published: April 2008

In this paper, we study on knots and closed incompressible surfaces in the 3-sphere via Morse functions. We show that both knots and closed incompressible surfaces can be isotoped into a "related Morse position" simultaneously. As an application, we have the following results. • Smallness of Montesinos tangles with length two and Kinoshita's theta curve. • Classification of closed incompressible and meridionally incompressible surfaces in 2-bridge theta-curve and handcuff graph complements and the complements of links which admit Hopf tangle decompositions.
Preparation of the PVA/TiO2 nanocomposite polymer membranes by a sol-gel process for alkaline DMFC
Authors: Yang Chun-Chen , Lin Che-Tseng 
Published: April 2008

The PVA/TiO2 nanocomposite polymer membrane was prepared by a sol-gel process. Glutaraldehyde (GA) and TiO2 particles were used as a crosslinker and the fillers for the composite polymer	membrane in order to increase their ionic conductivities, thermal and mechanical stability properties and to enhance the dimension stability. The characteristic properties of the	PVA/TiO2 nanocomposite polymer membranes were systematically	studied by X-ray diffraction (XRD), scanning electron	microscopy (SEM), thermal gravimetric analysis (TGA) and AC impedance spectroscopy. Alkaline DMFC, consisting of an air cathode electrode with MnO2/BP2000 (1:1) catalyst ink, an	anode	electrode with 4 mg cm-2 PtRu black coated on Ti-mesh,	respectively, and the PVA/TiO2 nanocomposite polymer membrane	based on titanium isopropylate (TTIP), was assembled and examined. It was revealed that the DMFC utilizing the PVA/TiO2 nanocomposite polymer membrane showed good electroc hemical performance at room temperature and ambient air. The maximum	power density of alkaline DMFC in 4M KOH + 2M CH3OH solution	is 11.47 mW cm-2 at ambient conditions.
Who Counts? On Democracy, Power, and the Incalculable
Authors: Schmidt Dennis 
Published: April 2008

AbstractThe intention of this paper is to discuss the notion and word "democracy" as a Greek legacy and then to pose the question of the specific challenges to that conception of democracy presented by this historical present, which Heidegger characterizes as the Gestell. Questions concerning the sources of power, the relation of power to peoples and individuals, as well as the shift from power to violence are addressed. Plato, Aristotle, Pericles, Lincoln, Derrida, and Heidegger are the key figures in this discussion.
Multimodel Estimation of Snow Microwave Emission during CLPX 2003 Using Operational Parameterization of Microphysical Snow Characteristics
Authors: Wójcik Rafał , Andreadis Konstantinos , Tedesco Marco , Wood Eric , Troy Tara , Lettenmeier Dennis 
Published: April 2008

AbstractExisting forward snow emission models (SEMs) are limited by knowledge of both the temporal and spatial variability of snow microphysical parameters, with grain size being the most difficult to measure or estimate. This is due to the sparseness of in situ data and the lack of simple operational parameterizations for the evolution of snowpack properties. This paper compares snow brightness temperatures predicted by three SEMs using, as inputs, predicted snowpack characteristics from the Variable Infiltration Capacity (VIC) model. The latter is augmented by a new parameterization for the evolution of snow grain morphology and density. The grain size dynamics are described using a crystal growth equation. The three SEMs used in the study are the Land Surface Microwave Emission Model (LSMEM), the Dense Media Radiative Transfer (DMRT) model, and the Microwave Emission Model of Layered Snowpacks (MEMLS). Estimated brightness temperature is validated against the satellite [Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E)] data at two sites from the Cold Land Processes Experiment (CLPX), conducted in Colorado in the winter of 2003. In addition, a merged multimodel estimate, based on Bayesian model averaging, is developed and compared to the measured brightness temperatures. The advantages of the Bayesian approach include the increase in the mean prediction accuracy as well as providing a nonparametric estimate of the error distributions for the brightness temperature estimates.
Vertical Velocity and Vertical Heat Flux Observed within Loop Current Eddies in the Central Gulf of Mexico
Authors: Rivas David , Badan Antoine , Sheinbaum Julio , Ochoa José , Candela Julio 
Published: April 2008

Abstract
Sixteen months of observations from a surface-to-bottom mooring in the central Gulf of Mexico show that acoustic Doppler current profilers (ADCPs) are useful for directly measuring the vertical velocity within mesoscale anticyclonic eddies, such as those shed from the Loop Current; and combining simultaneous temperature measurements, vertical heat flux can also be estimated (as a covariance of both variables). There is evidence of significant and coherent signals of vertical velocity ∼2–3 mm s−1 and vertical heat (temperature) transport ∼10−3 °C m s−1 during the presence of three anticyclones. A simple analysis shows downward flow near the eddies’ centers above 350 m and essentially upward flow in the peripheries, but below 700-m depth the pattern is indeed the opposite; however, further study is necessary to determine the eddies’ interior structures. The observations also suggest the existence of a vertical convergence of heat somewhere around 600-m depth, and estimations of adiabatic heat flux suggest that part of the converged heat, which is not recirculated within the eddy, must escape from the eddy and flow upward along the isopycnals up to the surface layers. This is in good agreement with previous results that have suggested that an excess heat gained by the Gulf in the intermediate levels through exchanges with the Caribbean Sea must be exported to the upper layers by an upward mean heat flux.