bluuebunny/crossref_metadata_2025 huggingface dataset:
Douglas-fir and white fir advance regeneration for renewal of mixed-conifer forests
Authors: Tesch Steven D. , Korpela Ed J.
Published: July 2007

Stem analysis of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and white fir (Abiesconcolor (Gord. & Glend.) Lindl.) advance regeneration 20 years after overstory removal showed that both species can respond in height growth to become dominant components of future stands on medium- to low-quality sites with a Mediterranean climate. Average annual height growth of both species nearly doubled on site classes III and IV during the first 5 years after release and continued to increase over the 20-year period of observation. Trees on the poorer site class V responded more slowly, but achieved similar 5-year periodic annual height growth after 20 years. Regression analyses indicated that prerelease height growth and site class were generally the most important variables in describing height growth after overstory removal, but regression equations left much variability in growth unexplained. Discriminant analysis was used to develop functions that identified trees meeting or exceeding specified levels of average annual height growth 5, 10, or 20 years after release; the classifications were generally successful at least 70% of the time.
Quantity, chemistry, and wettability of epicuticular waxes on needles of red spruce along a fog-acidity gradient
Authors: Percy K.E. , Jagels R. , Marden S. , McLaughlin C.K. , Carlisle J.
Published: July 2007

Needle wettability and epicuticular wax physicochemical characteristics were examined for red spruce (Picearubens Sarg.) trees growing along a gradient of fog quantity and acidity. Trees at four coastal and one inland site were sampled in November 1988 for three needle age-classes. Needle wettability was assessed by measuring needle–water droplet contact angles. Mean angles per site and age-class ranged from 73 to 42° and decreased significantly with increasing needle age. Needle contact angles were highly correlated with fog acidity (R = 0.99), decreasing with increasing acidity. Angles were lower on needles from declining trees than on needles from visually healthy trees. Epicuticular wax amount was highly correlated with quantity of fog collected at the sites (R = 0.99). Needles from trees at the inland site located outside the coastal fog zone had the smallest wax deposits, while needles from trees exposed to the greatest amount of fog had the largest wax deposits. Epicuticular wax was comprised of secondary alcohols (42%), diols (19%), alkyl esters (16%), primary alcohols (6%), hydroxy fatty acids (2%), and fatty acids (1%). Estolides (14%) in the wax were tentatively identified but not confirmed by mass spectrometry. Needles from trees exposed to the most fog had the greatest amounts of secondary alcohols and alkyl esters. Needles from trees not exposed to fog had greater amounts of diols. There was no obvious relationship between fog acidity and wax chemical composition.
Relationships among seed weight components, seedling growth traits, and predicted field breeding values in slash pine
Authors: Surles Scott E. , White Timothy L. , Hodge Gary R. , Duryea Mary L.
Published: July 2007

Dry weights of seed components (seed coat, gametophyte, and embryo), germination vigor (peak value and days to 50% germination), and three seedling growth traits (total height, stem dry weight, and shoot dry weight) under regimes of low (5 ppm) and high (50 ppm) nitrogen were measured for 64 open-pollinated families of slash pine (Pinuselliottii Engelm.) that have been field tested for 5- and 15-year volume growth. There were moderate to strong relationships among the seed components using the 64 family means (r = 0.80 between gametophyte weight and embryo weight; r = 0.68 between seed-coat weight and embryo weight; r = 0.50 between seed-coat weight and gametophyte weight). Seed-coat, gametophyte, and embryo weight, expressed as a percentage of total seed weight, were approximately 44, 50, and 6%, respectively, and those percentages were similar for small, medium, and large seed size classes. Family mean correlations between seed weight components and seedling growth traits were generally high at 12 weeks and decreased at 24 and 40 weeks, depending on the trait; however, most correlations remained statistically significant throughout the 80-week measurement. Correlations between seed components and seedling traits were generally higher in the high-N regime at 12 weeks, but by the 40- or 80-week measurements, correlations were generally higher in the low-N regime. Among the seed weight components, embryo weight consistently had the strongest relationship with seedling growth traits. Family mean correlations between germination vigor indices and seedling growth traits were high at 12 weeks, but declined significantly thereafter. Correlations between seed weight components and predicted field breeding values for 5- and 15-year volume growth were significantly greater than zero, and indicated that embryo weight in particular may be useful in genetic selection for volume growth. Owing to the strong relationship between seed weight components and shoot growth throughout the second growing season and beyond, statistical adjustments for seed weight effects in slash pine might remove useful genetic variation.
Effects of thinning and nitrogen fertilization on growth of Scots pine trees: total annual biomass increment, needle efficiency, and aboveground allocation of biomass increment
Authors: Valinger Erik
Published: July 2007

The effects of thinning and nitrogen fertilization, singly and in combination, on growth of 45-year-old Scots pine (Pinussylvestris L.) trees in northern Sweden were examined for 5 years after treatment. Annual examination of trees determined height growth, diameter growth, crown development, annual biomass increment, aboveground biomass allocation, and needle efficiency in relation to treatments. Nitrogen fertilization increased total dry matter production. The combination of thinning and nitrogen fertilization increased total dry matter production per tree more than the additive effects of thinning and nitrogen fertilization singly. Dry matter production per hectare was increased by nitrogen fertilization. Needle efficiency, i.e., total annual aboveground biomass production per unit of needle mass, was also increased by nitrogen fertilization. The increased aboveground production after nitrogen fertilization resulted from both an increase in biomass of needles and from the increased needle efficiency. The allocation pattern indicated that an increased production of stemwood was a result of a larger biomass of needles. An increase in cone production of the control trees was associated with a decrease in needle efficiency.
Relationship of the ratio of chlorophyll a to chlorophyll b and Douglas-fir seedling nutrient status
Authors: Bracher Grant A. , Murtha Peter A.
Published: July 2007

One–year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were treated with 24 nutrient solutions containing nitrogen, phosphorus, and sulphur levels ranging from 1 to 400 mg/L. After one growing season, newly matured needles were harvested, and foliar samples analyzed for nutrient and chlorophyll concentrations. Several nutrient deficiencies were diagnosed. A consistent and statistically significant relationship between the ratio of chlorophyll a to b and the severity of nutrient deficiency was not found; consequently, it appears ineffectual as an index of nutrient stress.
Preconditioning effects of nitrogen relative addition rate and drought stress on container-grown lodgepole pine seedlings
Authors: Stewart James D. , Lieffers Victor J.
Published: July 2007

Five-week-old Pinuscontorta var. latifolia Engelm. seedlings were subjected to 6 weeks of preconditioning with four combinations of watering and nitrogen fertilization, followed by a second 6-week period to evaluate the continuing effects of the preconditioning treatments. In both phases, the seedlings were fertilized with nitrogen at either 3 or 6%•d−1 relative addition rate and were either subjected to drought or well watered. Preconditioning treatments were crossed with second-phase treatments to give a 24 factorial design. Nitrogen and watering preconditioning effects on biomass, water relations, nutrients, and metabolic constituents persisted at least 6 weeks regardless of the second-phase treatments. Interaction between nitrogen and watering treatments applied simultaneously was found only in relative growth rate and foliar potassium concentration. Interactions between preconditioning and second-phase treatments were found in foliar nitrogen, potassium, and α-amino nitrogen concentrations, root water content, and xylem pressure potential. Foliar starch concentration increased when either nitrogen or water were limiting, but showed no evidence of interaction or preconditioning effect. Preconditioning at the lower nitrogen rate resulted in elevated reducing sugar concentration in the leaves, which persisted during the second-phase period. We did not detect an effect of increased reducing sugars on osmotic potential. Preconditioning at the lower nitrogen rate increased subsequent root weight ratio and reducing sugars concentration, which could contribute to drought resistance. Turgor regulation occurred via changes in cell wall elasticity rather than osmotic adjustment.
Estimating weights when fitting linear regression models for tree volume
Authors: Williams Michael S. , Gregoire Timothy G.
Published: July 2007

The method of weighted least squares can be used to achieve homogeneity of variance with linear regression that has a heterogeneous error structure. A weight function commonly used when constructing regression equations to predict tree volume is [Formula: see text], where k1 ≈ 1.0–2.1. This paper examines the weight function [Formula: see text] for modelling the error structure in two loblolly pine (Pinustaeda L.) data sets and one white oak (Quercusalba L.) data set. The weight function [Formula: see text] is recommended for all three data sets, for which the k1 values ranged from 1.80 to 2.07.
Effects of ozone and climate on ponderosa pine (Pinusponderosa) growth in the Colorado Rocky Mountains
Authors: Peterson David L. , Arbaugh Michael J. , Robinson Lindsay J.
Published: July 2007

Long-term radial growth trends of ponderosa pine (Pinusponderosa var. scopulorum) were studied in second-growth stands in the Front Range of the Colorado Rocky Mountains to determine if there has been any impact from oxidant air pollution. Although ozone concentrations are relatively high at some locations, visible pollutant injury was not found in any trees. Time series of basal area increments are generally homogeneous within stands. Concurrent periods of increasing and decreasing growth can be found in stands throughout the Front Range, which indicates that there are temporal growth trends at the regional level. Most of these trends appear to be related to the effects of stand dynamics and climate. Correlation analysis with climatic variables indicates that soil moisture supply is the dominant factor controlling interannual variation of basal area growth. Palmer hydrological drought index is highly correlated (positively) with growth during the summer months; total precipitation in spring is positively correlated with growth, and mean temperature in spring is negatively correlated with growth. There are no recent changes in growth trends that might be associated with elevated levels of ambient ozone in the Front Range.
Curly needle syndrome of loblolly pine seedlings
Authors: Stone Douglas M.
Published: July 2007

Curly shaped needles developed on loblolly pine (Pinustaeda L.) seedlings grown in lysimeters in two greenhouse studies. Nearly 80% of the seedlings from five half-sib families developed curly needles when watered weekly with one of four acid rain solutions. No abnormal needles developed on seedlings from the same seed lots growing on an adjacent bench and watered daily. In a second study, curly needles developed within 2 weeks after seedlings were transplanted into the lysimeters. Weekly misting of the foliage significantly reduced the proportion of fascicles with curly needles. Results indicate that curly needle syndrome is induced by water stress during needle elongation and suggest that wetting the foliage decreases the strength of the fascicle sheaths.
Influence of Quaternary history on the population genetic structure of Douglas-fir (Pseudotsugamenziesii) in the Great Basin
Authors: Schnabel Andrew , Hamrick J.L. , Wells P.V.
Published: July 2007

We used data from 20 enzyme loci to test hypotheses concerning the population genetic structure of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in the Great Basin relative to the southern Rocky Mountains of Utah. Detailed macrofossil data from wood rat (Neotoma) middens indicate that P. menziesii was absent from the central and northern Great Basin during the last glacial (20 000–12 000 years before present), but has recolonized several of the "island" mountain ranges of that region during the past 10 000 years by long-distance dispersal from populations on the southern Rocky Mountain "mainland". The genetic consequences of rare, chance dispersal events should be a reduction in levels of genetic diversity on Great Basin montane islands and more diversity among island populations relative to the Rocky Mountain mainland. We found moderate overall reductions in the level of polymorphism (65 vs. 85%), numbers of alleles per polymorphic locus (2.69 vs. 2.82), and gene diversity (0.113 vs. 0.141) in Great Basin P. menziesii relative to P. menziesii from the Rocky Mountain mainland. Within-population estimates of allozyme diversity, as well as relative partitioning of that diversity among populations of each region, differed to a lesser extent between island and mainland regions. Founder effects and genetic drift thus appear to have had a minor role in shaping the present-day genetic structure of Great Basin P. menziesii populations.
Limits to selection for disease resistance from natural tree populations
Authors: Kamp B.J. Van Der
Published: July 2007

It is demonstrated that for diseases characterized by a small number of discrete infections per tree, random placement of spores on trees results in substantial variation in the number of infections per tree. The consequences of this phenomenon for selection of resistant individuals and for natural selection are examined, using a previously reported distribution of susceptibility model for the western gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka)–lodgepole pine (Pinusconforta Dougl.) pathosystem as an example.
Selecting a sampling method to aid in vegetation management decisions in loblolly pine plantations
Authors: Weise David R. , Glover Glenn R.
Published: July 2007

Objective methods to evaluate hardwood competition in young loblolly pine (Pinustaeda L.) plantations are not widely used in the southeastern United States. Ability of common sampling rules to accurately estimate hardwood rootstock attributes at low sampling intensities and across varying rootstock spatial distributions is unknown. Fixed area plot, polyareal plot, and Batcheler's triple-point distance sampling estimators of hardwood rootstock density, total height, and crown area were evaluated using computer simulation. Rootstock age, density, and spatial pattern combinations defined 24 artificial populations representative of hardwood rootstocks found in young loblolly pine plantations. Relative bias, relative precision, and within-and between-sample variance of the estimators were used as evaluation criteria. Eighteen sampling estimators with sampling intensities of approximately 1% were evaluated. Mean relative bias ranged from 1.2 to 7.0%, −1.5 to 1.0%, and −3.8 to 3.4% for fixed area, polyareal, and distance estimators, respectively. Spatial pattern affected evaluation criteria. Relative precision was highest in uniform populations and lowest in clumped populations. Variance was lowest in uniform populations and highest in clumped populations. Batcheler's distance estimator performed poorly. The 0.01-acre (1 acre = 0.405 ha) circular plot, vertical line, and horizontal point estimators were deemed "best" for density, total height, and crown area estimation, respectively. Vertical line sampling estimated all three attributes well and is recommended for field testing in young conifer plantations.
Response of wildlife to forest herbicide applications in northern coniferous ecosystems
Authors: Lautenschlager R.A.
Published: July 2007

Reviewed studies of the effects of forest herbicide applications on wildlife often lacked replication, pretreatment information, and (or) were conducted for only one or two growing seasons after treatment. Because of these problems, as well as the use of dissimilar sampling techniques, study conclusions have sometimes been contradictory. A review of eight studies of the effects of herbicide treatments on northern songbird populations in regenerating clearcuts indicates that total songbird populations are seldom reduced during the growing season after treatment. Densities of species that use early successional brushy, deciduous cover are sometimes reduced, while densities of species which commonly use more open areas, sometimes increase. A review of 14 studies of the effects of herbicide treatments on small mammals indicates that like songbirds, small mammal responses are species specific. Some species are unaffected, while some select and others avoid herbicide-treated areas. Only studies that use kill or removal trapping to study small mammal responses show density reductions associated with herbicide treatment. It seems that some small mammal species may be reluctant to venture into disturbed areas, although residents in those areas are apparently not affected by the disturbance. Fourteen relevant studies examined the effects of conifer release treatments on moose and deer foods and habitat use. Conifer release treatments reduce the availability of moose browse for as long as four growing seasons after treatment. The degree of reduction during the growing season after treatment varies with the herbicide and rate used. Deer use of treated areas remains unchanged or increases during the first growing season after treatment. Eight years after treating a naturally regenerated spruce–fir stand browse was three to seven times more abundant on treated than on control plots (depending on the chemical and rate used). Forage quality (nitrogen, ash, and moisture) of crop trees increased one growing season after the soil-active herbicide simazine was applied to control competition around outplanted 3-year-old balsam fir seedlings.
Effects of a native forest pathogen, Phellinusweirii, on Douglas-fir forest composition in western Oregon
Authors: Holah Jenny C. , Wilson Mark V. , Hansen Everett M.
Published: July 2007

The fungal pathogen Phellinusweirii (Murrill) Gilbertson (Family: Hymenochaetaceae) causes extensive rot in the roots and bole of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and true firs, eventually leading to tree mortality. The native pathogen spreads slowly via root grafts and root contacts between conifers, leaving behind areas of tree mortality commonly called infection centers. This study determines (i) whether the slow, systematic removal of the Douglas-fir overstory by P. weirii changes the community composition of old-growth and mature forests, (ii) if composition is significantly affected, to what degree P. weirii influences the composition, (iii) what effects the disease has on individual populations, and (iv) whether vascular plant diversity is affected by disease presence. The herb, shrub, and tree strata were randomly sampled within and adjacent to six P. weirii infection centers located in the low-elevation Cascade and Coast ranges of western Oregon. Statistically significant (P ≤ 0.05) differences in species composition between infected and adjacent noninfected forest were found across all sites. Ordination techniques showed that the distance of vegetation to the infection center edge was a major factor underlying the forest community's structure. The average cover of all herbaceous species was higher inside infection centers as compared with outside, for all locations, though statistically significant at only two sites. In general, species differed in their responses to disease presence. Changes in diversity due to the presence of the root rot were statistically significant in three of the six cases (P ≤ 0.05) but the patterns of change differed from site to site. The removal of Douglas-fir overstory has strong effects on the plant community, but the specific patterns depend on the species and site involved.
Increased drought resistance of black locust seedlings via pretreatment of seeds with paclobutrazol
Authors: Hui-Juan Shen , Bin Zeng
Published: July 2007

The drought resistance of black locust (Robiniapseudoacacia L.) seedlings was increased by pretreatment of seeds with 250 ppm paclobutrazol. Treated seeds produced seedlings with thick roots and higher root/shoot ratios. During osmotic stress, treated plants displayed greater relative water content, lower electrolyte leakage, and fewer symptoms of wilt when compared with untreated black locust seedlings. Paclobutrazol-treated seedlings accumulated more proline than untreated seedlings in response to drought. However, osmotically induced accumulation of putrescine, a possible marker of cellular stress, was reduced in the treated plants.
A TWO-FLUID BGK LATTICE BOLTZMANN MODEL FOR IDEAL MIXTURES
Authors: PICO CARLOS ENRIQUE , DOS SANTOS LUÍS ORLANDO EMERICH , PHILIPPI PAULO CESAR
Published: July 2007

In the present work, a lattice Boltzmann model for binary mixtures is formally derived from a two-fluid kinetic model of Maxwell molecules by discretizing the Boltzmann equation. In this model, collisions among the same and different species are treated separately, as non-linear BGK terms, enabling the independent management of the fluid viscosities and the binary diffusion coefficient. The velocity space is discretized, in accordance with a quadrature method based on prescribed abscissas. A Chapman-Enskog analysis is performed for deriving the macroscopic mass and momentum transport equations. The model is verified against theoretical solutions for the concentration and velocity step problems.
IMMERSED BOUNDARY METHOD BASED LATTICE BOLTZMANN METHOD TO SIMULATE 2D AND 3D COMPLEX GEOMETRY FLOWS
Authors: CHEN DI-JIA , LIN KUN-HAO , LIN CHAO-AN
Published: July 2007

In this paper, the lattice Boltzmann method is combined with the immersed boundary technique to simulate complex geometry flows. The complex geometry is represented by Lagrangian markers and forces are exerted at the Lagrangian markers in order to satisfy the prescribed velocity of the boundary. This force at the Lagrangian markers is then distributed to the Eulerian grid by a well-chosen discretized delta function. With the known force field in the Eulerian grid to mimic the boundary, the lattice Boltzmann method is used to compute the flow field where the complex geometry is immersed inside the Cartesian computational domain. Numerical experiments show that the second-order accuracy of the adopted numerical scheme is degraded to 1.8 order. The proposed method is examined by computing decaying vortex, lid driven cavity flow and 2D and 3D flows over asymmetrically placed cylinder. All the numerical results are compatible with the benchmark solutions.
LATTICE BOLTZMANN METHOD FOR SIMULATION OF WEAKLY COMPRESSIBLE FLOWS AT ARBITRARY PRANDTL NUMBER
Authors: PRASIANAKIS N. I. , BOULOUCHOS K. B.
Published: July 2007

The entropic lattice Boltzmann (LB) method has recently been extended to include energy conservation in order to simulate weakly compressible flows. One of the limitations of this method when using the BGK collision model is the fixed Prandtl number. In this paper a new simple method is proposed and validated in order to simulate fluids of arbitrary Prandtl number.
THE OPENLB PROJECT: AN OPEN SOURCE AND OBJECT ORIENTED IMPLEMENTATION OF LATTICE BOLTZMANN METHODS
Authors: HEUVELINE VINCENT , LATT JONAS
Published: July 2007

The OpenLB project aims at setting up an open source implementation of lattice Boltzmann methods in an object oriented framework. The code, which is written in C ++, is intended to be used both by application programmers and by developers who may add their own particular dynamics. It supports advanced data structures that take into account complex geometries and parallel program executions. The programming concepts rely strongly on dynamic genericity through the use of object oriented interfaces as well as static genericity by means of templates. This design allows a straightforward and intuitive implementation of lattice Boltzmann models with almost no loss of efficiency. The aim of this paper is to introduce the OpenLB project and to depict the underlying structure leading to a powerful development tool for lattice Boltzmann methods.
GRAVITATIONAL PERFECT FLUID COLLAPSE WITH COSMOLOGICAL CONSTANT
Authors: SHARIF M. , AHMAD ZAHID
Published: July 2007

In this paper, the effect of a positive cosmological constant on spherically symmetric collapse with perfect fluid has been investigated. The matching conditions between static exterior and non-static interior spacetimes are given in the presence of a cosmological constant. We also study the apparent horizons and their physical significance. It is concluded that the cosmological constant slows down the collapse of matter and hence limit the size of the black hole. This analysis gives the generalization of the dust case to the perfect fluid. We recover the results of the dust case for p = 0.
THE BOUNDARY CONDITION MODEL APPROACH TO BORROMEAN NUCLEI
Authors: HATEGAN CORNEL , IONESCU REMUS AMILCAR , WOLTER HERMANN H.
Published: July 2007

Three-body systems are studied in the framework of the Boundary Condition Model, in which the relevant interactions are expressed in terms of the scattering lengths of the two-body subsystems. We demonstrate explicitly the role of resonant states in the two-body subsystems and of multiple scattering between the constituents in producing a weakly bound three-body system, i.e. a Borromean nucleus. We obtain qualitative relations between the spatial extension of the three-body bound state, its energy, and the scattering lengths in the subsystems. The results are compared with experimental data for the Borromean nucleus11Li and14Be .
Classical eyeblink conditioning during acute hypobaric hypoxia is improved in acclimatized mice and involves Fos expression in selected brain areas
Authors: López-Ramos J. C. , Yi P. J. , Eleore L. , Madroñal N. , Rueda A. , Delgado-García J. M.
Published: July 2007

This work attempts to evaluate the cognitive aspects of the acclimatization ability of mice submitted to simulated altitude. Critical altitudes were detected by evaluating open field activity, combined or not with object recognition tasks, at different acute simulated altitudes. Results showed impaired cognitive abilities at ≈3,733 m and above. To evaluate acclimatization capabilities, mice submitted to hypobaric hypoxia at ≈5,000 m for 1 wk were tested for learning and memory performances with classical eyeblink conditioning at the same altitude or at land altitude. Results showed total acclimatization in mice conditioned at ≈5,000 m but no improved performance in those conditioned at land altitudes compared with controls. Selected brain sites of conditioned animals were analyzed by immunohistochemistry to detect expression of the protein product of the protooncogene c-fos (Fos) in relation to both motor learning processes and hypobaric conditions. In the nucleus of the solitary tract, a higher expression of Fos was found in the acute hypobaric conditioned animals than in control conditioned and nonconditioned animals. Similar patterns between groups were found in the other brain areas, mainly in the piriform cortex and area 1 of the cingulate cortex and in the hippocampus. Differences between hemispheres were detected only in acute hypobaric animals. The present results show that acclimatization to high altitude prevents the impairment of classical eyeblink conditioning evoked by hypobaric hypoxic conditions but does not improve this task when acquired under land conditions, although it could diminish the activation requirements for its performance.
Mechanisms of Integrin–Vascular Endothelial Growth Factor Receptor Cross-Activation in Angiogenesis
Authors: Mahabeleshwar Ganapati H. , Feng Weiyi , Reddy Kumar , Plow Edward F. , Byzova Tatiana V.
Published: July 2007

The functional responses of endothelial cells are dependent on signaling from peptide growth factors and the cellular adhesion receptors, integrins. These include cell adhesion, migration, and proliferation, which, in turn, are essential for more complex processes such as formation of the endothelial tube network during angiogenesis. This study identifies the molecular requirements for the cross-activation between β
3
integrin and tyrosine kinase receptor 2 for vascular endothelial growth factor (VEGF) receptor (VEGFR-2) on endothelium. The relationship between VEGFR-2 and β
3
integrin appears to be synergistic, because VEGFR-2 activation induces β
3
integrin tyrosine phosphorylation, which, in turn, is crucial for VEGF-induced tyrosine phosphorylation of VEGFR-2. We demonstrate here that adhesion- and growth factor–induced β
3
integrin tyrosine phosphorylation are directly mediated by c-Src. VEGF-stimulated recruitment and activation of c-Src and subsequent β
3
integrin tyrosine phosphorylation are critical for interaction between VEGFR-2 and β
3
integrin. Moreover, c-Src mediates growth factor–induced β
3
integrin activation, ligand binding, β
3
integrin-dependent cell adhesion, directional migration of endothelial cells, and initiation of angiogenic programming in endothelial cells. Thus, the present study determines the molecular mechanisms and consequences of the synergism between 2 cell surface receptor systems, growth factor receptor and integrins, and opens new avenues for the development of pro- and antiangiogenic strategies.
Loss of Elastic Fiber Integrity and Reduction of Vascular Smooth Muscle Contraction Resulting From the Upregulated Activities of Matrix Metalloproteinase-2 and -9 in the Thoracic Aortic Aneurysm in Marfan Syndrome
Authors: Chung Ada W.Y. , Au Yeung Karen , Sandor George G.S. , Judge Daniel P. , Dietz Harry C. , van Breemen Cornelis
Published: July 2007

Thoracic aortic aneurysm (TAA) is the life-threatening complication of Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 gene. TAA is characterized by degradation of elastic fiber, suggesting the involvement of matrix metalloproteinase (MMP)-2 and -9, the activation of which is regulated by TIMP (tissue inhibitor of MMP) types 1 and 2. We hypothesized that MMP-2 and -9 were upregulated during TAA formation in Marfan syndrome, causing loss of elastic fibers and structural integrity. We studied mice, from 3 to 12 months, heterozygous for a mutant
Fbn
1 allele encoding a cysteine substitution in fibrillin-1 (
Fbn1
C1039G/+
, designated as “Marfan” mice) (n=120), the most common class of mutation in Marfan syndrome. The littermates,
Fbn1
+/+
served as controls (n=120). In Marfan aneurysmal thoracic aorta, mRNA and protein expression of MMP-2 and -9 were detected at 3 months and peaked at 6 months of age, accompanied by severe elastic fiber fragmentation and degradation. From 3 to 9 months, the MMP-2/TIMP-2 ratio increased by 43% to 63% compared with the controls. Dilated thoracic aorta demonstrated increased elasticity but distention caused a pronounced loss of contraction, suggesting weakening of the aortic wall. Breaking stress of the aneurysmal aorta was 70% of the controls. Contraction in response to depolarization and receptor stimulation decreased in the aneurysmal thoracic aorta by 50% to 80%, but the expression of α-smooth muscle actin between the 2 strains was not significantly different. This report demonstrates the upregulation of MMP-2 and -9 during TAA formation in Marfan syndrome. The resulting elastic fiber degeneration with deterioration of the aortic contraction and mechanical properties may explain the pathogenesis of TAA.
Pediatric Pelvic Osteomyelitis
Authors: Klein Joel D. , Leach Kathleen A.
Published: July 2007

Pelvic osteomyelitis is unusual in children. We retrospectively reviewed charts of patients with this infection seen at our institution. From 1998 to 2005, 31 patients with pelvic osteomyelitis were identified: 19 males and 12 females with an age range of 1.5 months to 17 years 9 months. Duration of illness prior to admission ranged from 1 day to 2.5 months. Chief complaints included nonspecific pain, fever, limp, and decreased weight bearing. Microorganisms isolated included Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella, Enterobacter cloacae, and Kingella kingae. Bones involved were acetabulum/ilium (22 patients), ischium (7 patients), and pubis (4 patients); 2 patients had several bones involved. Imaging studies performed included magnetic resonance imaging (21 patients), computed tomography (14 patients), and nuclear bone scan (25 patients). Our study, the largest contemporary series of pediatric pelvic osteomyelitis from one institution, highlights the consequences of prolonged duration of illness and delayed diagnosis.
Physician and Patient Characteristics Associated With Discussion of Psychosocial Health During Pediatric Primary Care Visits
Authors: Brown Jonathan D. , Wissow Lawrence S. , Riley Anne W.
Published: July 2007

This study examined whether physical pain, mental health symptoms, and provider characteristics were associated with the discussion of children's behavior, mood, getting along with others, school performance, family stress, and parent stress during 800 pediatric primary care visits to 54 providers in 13 clinics. The discussion of psychosocial health was more common when the child demonstrated hyperactivity symptoms, the visit was for a mental health problem, and the provider was a woman or reported greater confidence in mental health treatment skills, but less common when the child demonstrated physical pain. Provider gender, psychosocial orientation, the reason for the visit, and the child's characteristics did not explain the inverse relationship between pain and discussion. This suggests that multilevel factors that describe the child and provider are associated with the discussion of psychosocial health, and that pain interferes with discussion during all types of visits and during visits with children who are impaired by mental health symptoms.
Evaluation and Comparison of a 1-Month Versus a 2-Week Community Pediatrics and Advocacy Rotation for Pediatric Residents
Authors: DeLago Cynthia , Gracely Edward
Published: July 2007

This prospective study was conducted to assess the effects of a 4-week community pediatrics and advocacy rotation with a unique project (Curriculum A), a 2-week community pediatrics rotation with advocacy training and unique project throughout residency (Curriculum B), or no curriculum exposure on residents' attitudes, perceived competence, knowledge, and behaviors. A 27-item questionnaire was used to assess attitudes, competence, and knowledge. Examination of residents' patients' use of Early Intervention services during the 5-year period after curricula introduction assessed behaviors. Seventy percent of questionnaires distributed over several years were completed by 105 of 111 eligible residents. Residents exposed to Curriculum A or B demonstrated improved competence and knowledge but no significant increase in positive attitudes toward community pediatrics and advocacy. Residents' patients' use of Early Intervention services increased 65% during the 5-year period after curriculum introduction. No significant differences in outcome measures were observed between Curriculum A and Curriculum B.
A Call for Statistical Reform in EAQ
Authors: Byrd Jimmy K.
Published: July 2007

Purpose: The purpose of this study was to review research published by Educational Administration Quarterly (EAQ ) during the past 10 years to determine if confidence intervals and effect sizes were being reported as recommended by the American Psychological Association (APA) Publication Manual .

Research Design: The author examined 49 volumes of the journal, which included 245 articles from the most recent 10-year time frame. As the debate on statistical reform is focused on reporting confidence intervals and properly interpreting p values and null hypothesis statistical testing (NHST), the author examined all empirical studies from the 10-year time frame to determine if confidence intervals were included in the results and, if so, interpreted correctly. Because effect size measures are, alongside confidence intervals, at the heart of statistical reform goals in psychology, the author also examined effect-size practices in EAQ. Descriptive statistics (frequencies and percentages) were utilized to report the findings of the analysis.

Findings: The results of the descriptive analysis indicated that effect sizes were being reported in the majority of quantitative studies with limited interpretation. In contrast, no quantitative study examined from the 10-year time frame reported confidence intervals, despite the recommendations of the APA Task Force on Statistical Inference and guidelines outlined in the most recent edition of the APA Publication Manual . Recommendations for statistical reform in reporting quantitative results in EAQ are presented, and future direction is discussed.
Academic Drift, Institutional Production, and Professional Distribution of Graduate Degrees in Educational Leadership
Authors: Baker Bruce D. , Orr Margaret Terry , Young Michelle D.
Published: July 2007

Purpose: This article sheds light on some basic questions about the distribution of educational leadership preparation degree programs among different types of institutions and the distribution of advanced degrees, by type, exploring change over time and the relationship to regional labor market estimates.

Method: We used data from five major national data sets (Institutional Postsecondary Education Data System, Survey of Earned Doctorates, Schools and Staffing Survey, National Center for Education Statistics Common Core of Data, and Census data) to explore the production of graduate degrees in educational leadership by institutions of higher education and the distribution of graduate degrees across building level leaders in K-12 public education systems. We used two institutional classification systems— the Carnegie Classification and the U.S. News & World Report higher education classification—to group postsecondary institutions by resources and rank. The time period for our analysis is 1990 to 2003.

Findings: On the production side, we found that the number of graduate degree programs and degrees granted in educational leadership increased considerably from 1993 to 2003, with master's degree programs increasing by 16% and the number of master's degrees granted increasing by 90%. Degree production shifted by institutional type, with the role of research universities in producing master's, specialist, and doctoral degrees declining dramatically and Comprehensive colleges and universities showing over a four-fold increase in the share. Degree production fluctuates widely among states, unrelated to school population estimates, suggesting areas for further research and policy analysis.
Relationship Between the Density Profile and the Technological Properties of the Particleboard Composite
Authors: Nemli Gokay , Demirel Samet
Published: July 2007

Particleboard is one of the most important wood-based panel products on the market. The objectives of this study are to investigate the relationship between the density profile and some technological properties of particleboard and to determine the influences of press type, cold and hot press pressures, moisture content of the raw materials on the mechanical properties (modulus of rupture, modulus of elasticity and internal bond strength), physical properties (thickness swelling and density profile), and surface property (surface roughness) of three-layered particleboard composite. Based on the findings of this study, it appears that there exists a relationship between the density profile and technological properties of particleboard. The press type, cold and hot press pressures and moisture content of the raw materials are significantly found to be effective on all of the properties of the panels.
Matched or Mismatched Environments? The Relationship of Family and School Differentiation to Adolescents' Psychosocial Adjustment
Authors: Lohman Brenda J. , Kaura Shelby A. , Newman Barbara M.
Published: July 2007

This study applies the family-systems concept of differentiation (the balance of autonomy-granting and connectedness) to another primary system of adolescent development—school. This study assessed the relationships among levels of family and school differentiation to the externalizing and internalizing behaviors, peer group membership, and academic achievement of 693 middle and high school students. High levels of family and school differentiation were correlated with all measures of well-being. Individuals in the low-low matched differentiation group had the lowest academic achievement, whereas individuals in the high-high matched differentiation group had the highest academic achievement. Students in the mismatched group, who had high differentiation with parents, but low differentiation with school, had lower grade point averages, higher school absences, and higher disciplinary actions than those in the mismatched group with high school differentiation and low parent differentiation.
Factors Contributing to Differences in Substance Use Among Black and White Adolescents
Authors: Terling Watt Toni , McCoy Rogers Jesse
Published: July 2007

Research reveals that Black youth are less likely to use alcohol than White youth. It has been argued that Blacks are more likely to abstain because they have less disposable income, are more religious, and have more family support and/or control than White youth. It has also been suggested that not only are these compositional characteristics different and likely to suppress use rates but also that the effects of these factors vary as well. However, there are no comprehensive empirical investigations of these explanations. This study uses the Add Health Survey to examine alcohol and drug use by race and/or ethnicity and to explore how differences in composition and process might produce differences in use. Results suggest that the socioeconomic contexts of Black and White youth differ considerably. However, differences in alcohol use are almost entirely explained by differences in process, in particular, the influence of peers and the family.
Medicaid, Medicare, and the Michigan Tumor Registry: A Linkage Strategy
Authors: Bradley Cathy J. , Given Charles W. , Luo Zhehui , Roberts Caralee , Copeland Glenn , Virnig Beth A.
Published: July 2007

The study of health outcomes and the reduction in health disparities is at the forefront of the nation's health care agenda. A theme in the disparities literature is the call for a data infrastructure that can track progress toward goals aimed at reducing differences in health outcomes. This article describes a strategy for linking Medicaid, Medicare, and Michigan Tumor Registry data for the purposes of studying disparities in cancer diagnosis, quality of care, and survival. The authors review their procedures for ensuring that a correct match between files occurred and offer guidance for merging and assessing the quality of these complex linked data sets. A cohort of 113,604 subjects (90%) from a population of 125,900 subjects was correctly linked from the Michigan Tumor Registry to Medicare and Medicaid files. Using probabilistic and deterministic methods, the prediction rate of the Medicaid match to the Michigan Tumor Registry was 93%. Approximately 13% of the subjects were dually eligible for Medicare and Medicaid. An expansive data set reflecting the Medicare and Medicaid medical service utilization and outcomes for a cohort of individuals age 65 years and older when diagnosed with cancer was created. This data set serves as a cornerstone of a health outcomes data infrastructure. The methodology described may serve as a model for other researchers seeking to create a similar data set in their state.
Creating High-quality Paths for Motion Planning
Authors: Geraerts Roland , Overmars Mark H.
Published: July 2007

Many algorithms have been proposed that create a path for a robot in an environment with obstacles. Most methods are aimed at finding a solution. However, for many applications, the path must be of a good quality as well. That is, a path should be short and should keep some amount of minimum clearance to the obstacles. Traveling along such a path reduces the chances of collisions due to the difficulty of measuring and controlling the precise position of the robot. This paper reports a new technique, called Partial shortcut, which decreases the path length. While current methods have difficulties in removing all redundant motions, the technique efficiently removes these motions by interpolating one degree of freedom at a time. Two algorithms are also studied that increase the clearance along paths. The first one is fast but can only deal with rigid, translating bodies. The second algorithm is slower but can handle a broader range of robots, including three-dimensional free-flying and articulated robots, which may reside in arbitrary high-dimensional configuration spaces. A big advantage of these algorithms is that clearance along paths can now be increased efficiently without using complex data structures and algorithms. Finally, we combine the two criteria and show that high-quality paths can be obtained for a broad range of robots.
Promoting Effective Interviewing of Sexually Abused Children: A Pilot Study
Authors: Cheung Monit
Published: July 2007

Objective: This study is centered on interviewing techniques with alleged child sexual abuse victims who do and do not disclose sexual abuse. Method: Ninety randomly selected videotapes are reviewed, and the interviewing techniques are recorded on a 69-item Child Sexual Abuse Interviewing Skills Instrument. Results: The nondisclosure children are younger and more likely to be males than females. The discriminant analysis of the instrument indicate the use of more “what and how” questions in disclosure cases, whereas more closing questions are used in nondisclosure cases. Conclusions: Interviewers should maintain an attitude that additional information can be obtained from other sources, which will help the interviewer demonstrate patience and understanding, rather than leading the child to disclosure or false allegation.