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The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) is a nonnative phloem-feeding beetle that was accidentally introduced near Detroit, Michigan, two to three decades ago. North American ash (Fraxinus spp.) exhibit little or no resistance, and as this insect species expands its range, extensive mortality results. Previous studies of the impacts of EAB, typical of most insect and disease impact studies, utilized data acquired from sites with known infestations and cannot be used to make regional estimates of change on forest land. By contrast, this study investigated the regional impacts of EAB on the affected resource using information from a large-scale forest inventory (Forest Inventory and Analysis program of the US Department of Agriculture, Forest Service) previously implemented to estimate regional forest resources. Results indicate that since 1980, ash has been increasing throughout many of the Great Lakes States but EAB is reversing this trend in recently invaded areas. Within 50 km of the epicenter of the EAB invasion, a major decline was observed after 2004. For growing stock (trees at least 12.7 cm diameter at breast height), average ash volume decreased from 12.7 to 3.2 [[m.sup.3]*ha.sup.-1] and mortality increased from 0.1 to 1.4 [[[m.sup.3]*ha.sup.-1]*year.sup.-1] on timberland between the 2004 and 2009 inventories. L'agrile du frene (AF) (Agrilus planipennis Fairmaire) est un insecte exotique qui se nourrit du phloeme et qui a ete introduit accidentellement pres de Detroit, au Michigan, il y a deux ou trois decennies. Les especes nord-americaines de frene (Fraxinus spp.) sont peu ou pas resistantes et, a mesure que cet insecte etend son aire de repartition, il cause beaucoup de mortalite. Les etudes anterieures portant sur l'impact de l'AF, typiques des etudes d'impact d'insectes et de maladies, ont utilisees des donnees provenant d'endroits ou la presence de l'insecte etait connue et ne peuvent etre utilisees pour faire des estimations regionales des changements dans les zones boisees. Nous examinons au contraire les impacts regionaux de l'AF sur les ressources qui sont touchees en utilisant l'information provenant d'un inventaire forestier a grande echelle (le pro-gramme d'analyse et d'inventaire forestier du Service forestier des Etats-Unis) qui a ete implante pour estimer les ressources forestieres regionales. Les resultats indiquent que depuis 1980, la presence du frene a augmente dans plusieurs Etats des Grands Lacs mais que l'AF est en train de renverser cette tendance dans les zones recemment envahies. A l'interieur d'un perimetre de 50 km de l'epicentre de l'infestation de l'AF, un important deperissement a ete observe apres 2004. Pour le materiel sur pied (arbres dont le diametre a hauteur de poitrine est d'au moins 12,7 cm), le volume moyen de frene a dimi-nue de 12,7 a 3,2 [[m.sup.3]*ha.sup.-1] et la mortalite a augmente de 0,1 a 1,4 [[[m.sup.3]*ha.sup.-1]*an.sup.-1] sur les terrains forestiers entre les inventaires de 2004 et 2009. [Traduit par la Redaction], Introduction Over the last 100 years, nonnative forest insects have been establishing in the United States at a rate of approximately 2.5 species per year (Mattson et al. 1994; Aukema [...]

Abstract: Beech bark disease (BBD) is an insect-fungus complex involving the beech scale insect (Cryptococcus fagisuga Lind.) and one of two canker fungi. Beech scale was introduced to Halifax, Nova [...]

Diets deficient in an indispensable amino acid have long been known to suppress food intake in rats. Detection of dietary deficiency takes place in the anterior piriform cortex (APC). Recent studies showed that the response to amino acid deficiency takes as little as 15 min to develop, but few data exist to correlate the concentration of amino acids in the APC with this rapid response. The purpose of this study was to measure the concentration of amino acids in the APC in a behaviorally relevant time frame. Rats were preconditioned by consumption of a basal diet for 7-10 d, and then given a test diet with either a control or deficient amino acid profile. Both the threonine- and leucine-deficient diets reliably depleted threonine and leucine concentration in the APC within 30 min, respectively. The control diets and a diet lacking the dispensable amino acid glycine did not lead to amino acid depletion. In combination with previous studies, the present results show that the decrease in the concentration of indispensable amino acids in the APC may be the initial sensory signal for recognition of dietary amino acid deficiency. KEY WORDS: * amino acid imbalance * anterior piriform cortex * threonine * leucine

Landscape-scale maps of tree species densities are important tools for managing ecosystems threatened by forest pests. Eastern hemlock dominates riparian forests throughout its range. As a conifer in a deciduous landscape, hemlock plays an ecohydrological role, especially when other species are dormant. The nonnative, hemlock woolly adelgid has caused widespread hemlock decline and mortality. We used two existing basal area raster layers first to identify Chesapeake Bay subwatersheds with ≥6 percent hemlock basal area and second to quantify hemlock basal area densities within fixed-width riparian buffers of 50 m, 100 m, 250 m, and 500 m. Hemlock densities were higher in riparian zones compared with entire subwatersheds. In five subwatersheds, 50 m and 100 m zones had higher percentages of pixels with ≥25 percent hemlock basal area. We produced maps identifying hemlock riparian densities in the Pine Creek Watershed, which managers can use to prioritize sites for supplemental conifer planting under anticipated hemlock decline. [ABSTRACT FROM AUTHOR]

Worldwide, forests are increasingly affected by nonnative insects and diseases, some of which cause substantial tree mortality. Forests in the United States have been invaded by a particularly large number (>450) of tree-feeding pest species. While information exists about the ecological impacts of certain pests, regionwide assessments of the composite ecosystem impacts of all species are limited. Here we analyze 92,978 forest plots distributed across the conterminous United States to estimate biomass loss associated with elevated mortality rates caused by the 15 most damaging nonnative forest pests. We find that these species combined caused an additional (i.e., above background levels) tree mortality rate of 5.53 TgC per year. Compensation, in the form of increased growth and recruitment of nonhost species, was not detectable when measured across entire invaded ranges but does occur several decades following pest invasions. In addition, 41.1% of the total live forest biomass in the conterminous United States is at risk of future loss from these 15 pests. These results indicate that forest pest invasions, driven primarily by globalization, represent a huge risk to US forests and have significant impacts on carbon dynamics. [ABSTRACT FROM AUTHOR]

Highlights • Sirococcus tsugae causes a prevalent disease of eastern hemlock in Eastern USA. • In most locations, eastern hemlock regeneration was damaged by more than one agent. • The effect of more than one damaging agent on crown defoliation was additive. • Sirococcus shoot blight is positively correlated with hemlock density. • Sirococcus shoot blight intensified in permanent plots surveyed from 2011 to 2013. Abstract In 2009, Sirococcus tsugae was first reported in Maine on eastern hemlock. Our goal was to quantify the impact of the shoot blight disease caused by this fungal pathogen of unknown origin on eastern hemlock regeneration. From 2013 to 2014, 59 long-term monitoring plots established by the US Forest Service (USFS) Forest Inventory and Analysis (FIA) program in New England and New York were surveyed to determine the impact of S. tsugae. Damage by hemlock woolly adelgid (Adelges tsugae), elongate hemlock scale (Fiorinia externa), white-tailed deer (Odocoileus virginianus), or other causes was also recorded. Disease incidence and severity (percentage of shoots blighted and percentage of crown defoliated) were assessed for 20 seedlings per plot. Sirococcus shoot blight symptoms were present in most plots (90%) and on most seedlings (72%). For the majority of seedlings, blight affected less than 10% of shoots, but the percentage of shoots blighted did range up to 75%. Similarly, needle loss was limited to less than 25% of the crown for most seedlings. Disease severity was positively correlated with overstory hemlock density. Using species-specific polymerase chain reaction (PCR) primers, Sirococcus tsugae was identified from samples collected in the majority of sites (68%) in New England and New York. In permanent plots at the Massabesic Experimental Forest in Maine, disease symptom severity increased from 16% blighted shoots in 2011 to 47% blighted shoots in 2013. Results confirm that Sirococcus shoot blight of eastern hemlock is more widespread in natural forests of northeastern USA than previously known and that symptoms can be severe (>75% blighted shoots) in some locations. [ABSTRACT FROM AUTHOR]

Hickory ( Carya spp.) is an economically and ecologically important genus to the eastern deciduous forest of North America. Yet, much of our knowledge about the genus comes from observational and anecdotal studies that examine the genus as a whole, or from research that examines only one species, in only one part of its range. Here, we use data sets from three different spatial scales to determine the demographics and regeneration patterns of the four most abundant hickory species in the Northeastern United States. These species were the shagbark ( C. ovata ), pignut ( C. glabra ), mockernut ( C. tomentosa ), and bitternut ( C. cordiformis ) hickories. We examine trends in hickory demographics, age class and structure at the regional scale (New England and New York), the landscape scale (a 3000 ha forest in northwestern Connecticut) and at the stand scale (0.25–5 ha). Our analysis at all three scales show that individual hickory species are site specific with clumped distribution patterns associated with climate and geology at regional scales; and with soil moisture and fertility at landscape scales. Although hickory represents a fairly small percent of the total basal area (2.5%) across a forest landscape, upland oak-hickory stands can have a much higher basal area of hickory (49%), especially in the larger height and diameter classes. Additionally, dendrochronological results show that hickory trees in mature, second growth forests originated or were released over a half-century long period of stand development; but patterns in seedling recruitment in the understory is continuous and builds up as advance regeneration over decades, with some surviving in a suppressed state for over forty years. This contrasts with oak where recruitment of regeneration is strongly pulsed in association with mast years. [ABSTRACT FROM AUTHOR]

Evaluating the causes of spatial synchrony in population dynamics in nature is notoriously difficult due to a lack of data and appropriate statistical methods. Here, we use a recently developed method, a multivariate extension of the local indicators of spatial autocorrelation statistic, to map geographic variation in the synchrony of gypsy moth outbreaks. Regression analyses indicated that local synchrony of gypsy moth defoliation increased with the local synchrony of precipitation and the proportion of host tree density composed of oaks, especially those in the Lobatae (red oak) section. This may be the first study that demonstrates a relationship between defoliator population synchrony and host tree composition. More broadly, this study contributes to a small body of recent work that illustrates how mapping hotspots of unusually high or low synchrony facilitates an improved understanding of factors influencing spatially synchronous population dynamics generally, and triggers of pest insect outbreaks, more specifically. [ABSTRACT FROM AUTHOR]

This work investigated the effect of 3 days of 500 mg/day dietary curcumin supplementation on gastrointestinal barrier damage and systems-physiology responses to exertional heat stress in non-heat-acclimated humans. Eight participants ran (65% *O2max) for 60 min in a Darwin chamber (37°C/ 25% relative humidity) two times (Curcumin/Placebo). Intestinal fatty acid-binding protein (I-FABP) and associated proinflammatory [monocyte chemoattractant protein-1, tumor necrosis factor-α (TNF-α), interleukin- 6] and anti-inflammatory [interleukin-1 receptor antagonist (IL- 1RA), interleukin-10 (IL-10)] cytokines were assayed from plasma collected before (Pre), after (Post) and 1 (1-Post) and 4 (4-Post) h after exercise. Core temperature and HR were measured throughout exercise; the physiological strain index (PSI) was calculated from these variables. Condition differences were determined with 2-way (condition x time) repeated-measures ANOVAs. The interaction of condition x time was significant (P < 0.05) for I-FABP and IL-1RA. Post hoc analysis indicated I-FABP increased more from Pre to Post (87%) and 1-Post (33%) in Placebo than in Curcumin (58 and 18%, respectively). IL-1RA increased more from Pre to 1-Post in Placebo (153%) than in Curcumin (77%). TNF-α increased (P < 0.01) from Pre to Post (19%) and 1-Post (24%) in Placebo but not in Curcumin (P > 0.05). IL-10 increased (P < 0.01) from Pre to Post (61%) and 1-Post (42%) in Placebo not in Curcumin (P > 0.05). The PSI, which indicates exertional heatstroke risk, was also lower (P < 0.01) in Curcumin than Placebo from 40 to 60 min of exercise. These data suggest 3 days curcumin supplementation may improve gastrointestinal function, associated cytokines, and systems-level physiology responses during exertional heat stress. This could help reduce exertional heatstroke risk in non-heat-acclimated individuals. [ABSTRACT FROM AUTHOR]

Butternut trees dying from a canker disease were first reported in southwestern Wisconsin in 1967. Since then, the disease has caused extensive mortality of butternut throughout its North American range. The objectives of this study were to quantify changes in butternut populations and density across its range and identify habitat characteristics of sites where butternut is surviving in order to locate regions for potential butternut restoration. The natural range of butternut ( Juglans cinerea L.) extends over a large region of eastern N. America encompassing New Brunswick south to North Carolina, north to Minnesota, and southwest to Missouri. Despite the species' large range, it is typically not a common tree, comprising a relatively minor component of several different forest types. We evaluated change in butternut abundance and volume from current and historic data from 21 states in the eastern United States. We related abundance and volume at two time periods to a suite of ecological and site factors in order to characterize site conditions where butternut survived. We also assessed the current level of butternut mortality across its range. Since the 1980s, the number of butternut trees and butternut volume have decreased by 58% and 44%, respectively, across its US range. Substantial relative decreases in tree numbers and volume occurred in most ecoregion sections. Five environmental variables were found to be significant predictors of butternut presence. The potential impacts of butternut canker are particularly acute as the canker pathogen invasion pushes a rare tree species toward extinction, at least at a local scale. Based on the results presented here, large-diameter maple/beech/birch stands in dry, upland sites in eastern Minnesota, western Wisconsin, and upstate New York appear to offer the most favorable conditions for butternut growth and survival and thus may be the best stands for planting resistant butternut trees. [ABSTRACT FROM AUTHOR]

The first stereocontrolled Cu-catalyzed sequential 1,6/1,4-asymmetric conjugate addition (ACA) of C-metalated hard nucleophiles to cyclic dienones is reported. The use of DiPPAM (diphenylphosphinoazomethinylate) followed by a phosphoramidite as the stereoinducing ligands facilitated both high ee values for the 1,6-ACA and high de values for the 1,4-ACA reaction components, which thus gave enantioenriched 1,3-dialkylated moieties. The absolute configurations were determined by using vibrational circular dichroism (VCD) and optical rotatory dispersion (ORD) spectroscopy, in combination with DFT calculations and X-ray analysis. Interestingly, DFT calculations for the mechanism of enantioselective 1,6-addition by using an unprecedented Cu-Zn bimetallic catalytic system confirmed this attribution. Lastly, exploring intramolecular cyclization avenues for enantioenriched 1,3-dialkylated products provided access to the challenging drimane skeleton. [ABSTRACT FROM AUTHOR]

Disturbanceby non-native insect speciescanbeanimportant ecological driver shaping long-term changes in vegetation and plant species composition. While impacts of gypsy moth (Lymatria dispar L.) outbreaks in North American forests have been extensively studied, the results are quite inconsistent, particularly with respect to the amount of tree mortality associated with defoliation. In this study, we integrate geographical data describing historical gypsy moth defoliation with forest inventory data collected by a national forest inventory programme to quantify regional impacts across several million hectares of forest land in the northeastern US. While observed increases in host tree mortality rates and decreases in growth rates associated with defoliation were expected, the study also indicates that this overstory mortality, coupled with ongoing declines in oak regeneration, will result in a long-term reduction of oak density in defoliated areas. Eventually, these impacts will likely contribute to regional shifts in tree species composition and forest succession pathways. Gypsy moth outbreaks thus appear to exacerbate ongoing declines in young oak age classes in the region. [ABSTRACT FROM AUTHOR]

An efficient copper-catalyzed enantioselective conjugate addition of dimethylzinc to α,β- and α,β,γ,δ-unsaturated 2-acyl-N-methylimidazoles has been achieved using a chiral bidentate hydroxyalkyl-NHC ligand. The reactions proceeded with both excellent regio- and enantioselectivity (14 examples, 87-95 % ee) to afford the desired 1,4-adducts, which were easily transformed to the corresponding aldehydes, esters, and ketones. Subsequently, this powerful methodology was therefore successfully applied in the synthesis of natural products. Furthermore, an iterative process was also disclosed leading to highly desirable 1,3-desoxypropionate skeletons (up to 94 % d.e.). [ABSTRACT FROM AUTHOR]

While invasions of individual non-native phytophagous insect species are known to affect growth and mortality of host trees, little is known about how multiple invasions combine to alter forest dynamics over large regions. In this study we integrate geographical data describing historical invasion spread of the hemlock woolly adelgid, Adelges tsugae , and beech scale, Cryptococcus fagisuga , with regional forest inventory data collected by the US Forest Service’s Forest Inventory and Analysis program to quantify the individual and combined impacts of these pest species. This analysis indicates that regional impacts of these insects on their hosts occur surprisingly slow but act to change regional forest succession pathways. Because beech and hemlock commonly co-occur in eastern North American forests, invasions by the two pest species are altering the current and future composition of large forest regions through their impacts on these two late-successional species. Such results demonstrate how forest insect invasions can profoundly modify forest dynamic processes, resulting in long-term changes in forest ecosystems. [ABSTRACT FROM AUTHOR]

A multicomponent strategy was applied to the synthesis of chiral bidentate unsaturated hydroxyalkyl- and carboxyalkyl- N-heterocyclic carbene (NHC) precursors. The newly developed low-cost chiral ligands derived from amino alcohols and amino acids were evaluated in copper-catalyzed asymmetric conjugated addition and asymmetric allylic alkylation, which afforded the desired tertiary and quaternary carbon stereocenters with excellent regio- and enantioselectivities (up to 99:1 e.r.). [ABSTRACT FROM AUTHOR]

Many classroom climate studies suffer from 2 critical problems: They (a) treat climate as a student-level (L1) variable in single-level analyses instead of a classroom-level (L2) construct in multilevel analyses; and (b) rely on manifest-variable models rather than on latent-variable models that control measurement error at L1 and L2, and sampling error in the aggregation of L1 ratings to form L2 constructs. On the basis of an analysis of 2,541 students in Grades 5 or 6 from 89 classrooms, the authors demonstrate doubly latent multilevel structural equation models that overcome both of these problems. The results show that L2 classroom climate (a higher-order factor representing classroom mastery goal orientation, challenge, and teacher caring) had positive effects on self-efficacy and achievement. The authors conclude with a discussion of related issues (e.g., the meaning of L2 constructs vs. L1 residuals, the dimensionality of climate constructs at L2) and guidelines for future research. [Supplementary materials are available for this article. Go to the publisher's online edition of The Journal of Experimental Education for the following free supplemental resource(s): Appendices and Supplemental Tables.] [ABSTRACT FROM AUTHOR]

The design of a new class of chiral1,3-dipoles for enantioselectivecycloaddition reactions is reported. These phosphorus-based dipolesare easily formed (from imines, acid chlorides, and chiral phosphites),rigidly chiral, and undergo intramolecular alkene cycloaddition withhigh enantioselectivity. Overall, this provides a straightforwardand modular approach to synthesize chiral 2-pyrrolines and pyrrolidinesin up to 99% ee. [ABSTRACT FROM AUTHOR]

Since its introduction, the non-native hemlock woolly adelgid ( Adelges tsugae) has spread to infest hemlock ( Tsuga spp.) in at least 18 states in the eastern USA. Previous studies have documented highly variable rates of hemlock mortality among infested stands making it difficult to estimate regional impacts. Here data from the US Forest Service Forest Inventory and Analysis program collected from 432 eastern U.S. counties reveals several surprising and conflicting regional patterns. First, median live and dead hemlock basal area has generally increased over the last two decades across the eastern U.S. This has generally been the case in both infested and uninfested counties. Second, the median percentage of hemlock which is alive has decreased over the past ~20 years, again in both infested and uninfested counties. Third, the ages of infestations are negatively correlated with the percentage of live hemlock, as might be expected given the known impact adelgids can have on a stand through time; however this relationship depends on the exclusion of uninfested counties, as counties infested >12 years and uninfested counties have similar percentages of live hemlock. Combined, these data suggest increasing tree density associated with the past century of reforestation and succession in the eastern U.S. may currently be overwhelming the negative impacts of the adelgid at the regional scale, however, the long-term stability of this situation is not known, and data from long-infested counties suggest the landscape may be at a “tipping point”. [ABSTRACT FROM AUTHOR]

1,3-Dipolar cycloadditions of mesoionic 1,3-dipoles (Münchnones, imino-Münchnones, and phospha-Münchnones) with alkynes offer versatile, modular synthetic routes to pyrroles. Reactivity and regioselectivity differ markedly for different members of this series, and we report here the first general rationale for differences in reactivity by means of a systematic investigation of 1,3-dipolar cycloadditions involving electron-poor and electron-rich alkynes. Competition kinetic measurements indicate that Münchnones and phospha-Münchnones are nucleophilic 1,3-dipoles that react most rapidly with electron-poor alkynes. However, the regioselectivities of cycloadditions are found to undergo an inversion as a function of alkyne ionization potential. The exact point at which this occurs is different for the two dipoles, allowing rational control of the pyrrole formed. The origins of these reactivities and regioselectivities are examined computationally. Frontier molecular orbital predictions are found not to be accurate for these reactions, but transition state calculations give correct predictions of reactivity and selectivity, the origins of which can be analyzed using the distortion/interaction model of reactivity. Cycloadditions with electron-poor alkynes are shown to favor the regioisomer that has either the most favorable TS interaction energy (Münchnones or imino-Münchnones) or the smallest TS distortion energy (phospha-Münchnones). Cycloadditions with more electron-rich aryl-substituted alkynes, on the other hand, generally favor the regioisomer that has the smaller TS distortion energy. These insights delineate the synthetically important distinctions between Münchnones and phospha-Münchnones: phospha-Münchnones undergo highly regioselective cycloadditions with electron-poor alkynes that do not react selectively with Münchnones, and the reverse is true for cycloadditions of Münchnones with electron-rich alkynes. [ABSTRACT FROM AUTHOR]

CC coupling: DiPPAM 1 and BINAP 2 ligands led to divergent behaviors in the asymmetric conjugate addition (ACA) of dialkylzinc reagents to linear aryldienones, which were applied to the development of a highly selective sequential asymmetric 1,6/1,4‐ACA process (see scheme; Tf = triflate, DBU = 1,8‐diazabicyclo[5.4.0]undec‐7‐ene). [ABSTRACT FROM AUTHOR]

Highlights: [•] Crown width models were applied to trees in large-area forest inventory data. [•] Amount of canopy cover was determined by accounting for crown overlap using GIS. [•] This process links area to individual-tree attributes (e.g., diameter and height). [•] The area: tree link creates a new analytical model for contemporary forest issues. [•] Canopy area may provide new information not contained in usual forest descriptors. [ABSTRACT FROM AUTHOR]

Classroom context and climate are inherently classroom-level (L2) constructs, but applied researchers sometimes—inappropriately—represent them by student-level (L1) responses in single-level models rather than more appropriate multilevel models. Here we focus on important conceptual issues (distinctions between climate and contextual variables; use of classroom L2 rather than student-level L1 measures) and more appropriate multilevel models. To illustrate these issues, we consider the effects of two L2 classroom climate variables and one L2 classroom contextual variable on two L1 student-level outcomes for 2261 students in 128 classes. Through this example, we illustrate how to apply evolving doubly latent multilevel models to (a) evaluate the factor structure of L1 and L2 constructs based on multiple indicators of classroom climate and context measures, (b) control measurement error at L1 and L2, (c) control sampling error in the aggregation of L1 responses to form L2 constructs (the average of student-level responses to form classroom-level constructs), and (d) provide guidelines for appropriate analysis of classroom climate as an L2 construct. [Supplementary materials are available for this article. Go to the publisher's online edition of Educational Psychologist for the following free supplemental resources: Substantive basis of the present investigation and more detailed description of the methodology.] [ABSTRACT FROM PUBLISHER]

The article focuses on the U.S. Supreme Court case Ortiz v. Jordan, in which the Court eliminated the ability for a party to appeal on orders denying summary judgment after a trial. Topics include the prohibition of challenges to pre-trial judgments, appellate review through interlocutory appeal, and the U.S. Federal Rules of Civil Procedure.

The reaction of imines, acid chlorides, PR3, and base generates a new class of 1,3-dipoles: phospha-Münchnones. These 1,3-dipoles can undergo cycloadditions with alkynes followed by loss of phosphine oxides to form pyrroles. Cycloaddition reactivity is dependent upon the PR3 employed, with PhP- (catechyl) (catechyl = o-O2C6H4) providing the most rapid cycloadditions and optimal pyrrole yields. 1H, 13C, and 31P NMR analysis and computations indicate that electron-poor catechyl-substituted phosphonites and phosphites favor a cyclic 1,3-dipolar structure, while more electron-rich phosphines instead favor the valence tautomeric acyclic ylides. X-ray crystallographic studies confirm this. Density functional theory calculations support the wide variety of P-O interactions induced by different PR3 groups and indicate that the most efficient concerted 1 ,3-dipolar cycloadditions are those for dipoles whose ground-state geometry is most like the transition-state geometry. Reactions of these dipoles with monosubstituted alkynes bearing an electron-withdrawing group are calculated to occur by stepwise mechanisms. The presence of the phosphorus unit creates a large electronic bias across the 1,3-dipole, allowing for regioselective cycloadditions with substituted alkynes. [ABSTRACT FROM AUTHOR]

We conducted a series of studies to investigate the psychometric properties of the Social Physique Anxiety Scale (SPAS; Hart, Leary, & Rejeski, 1989) among a total sample of 1,563 nonclinical French adolescents. The, first study provided support for the item content of the preliminary version of the French SPAS for adolescents. Then, the second study supported the convergent validity of the English and French version of the SPAS. Finally, Studies 3 to 6 provided support for the factor validity, measurement invariance (across genders, age groups and samples), latent mean structure invariance (across age category and samples), reliability, convergent validity, and criterion-related validity of a 7-item version of the SPAS. [ABSTRACT FROM AUTHOR]

Abstract: Intensive Forest Inventory and Analysis (FIA) plot data collected in the Allegheny National Forest (ANF), Pennsylvania, between 1999 and 2006 were evaluated for their ability to predict ANF’s vulnerability to invasion by exotic plants. A total of 26 variables classified by biotic, abiotic, or disturbance characteristics were examined. Likelihood of colonization by invasive exotic and non-invasive exotic plants was analyzed using a logistic regression model. Approximately, 11% of the 449 species documented in these plots were exotic, which is higher than has been found in other northeastern forested plots. Only 1% of the ANF flora was invasive exotic plants and these were at low abundance, confirming that most invasions are still at an early stage of establishment. Sites richer in native or non-invasive exotic plants and with more alkaline soils were more likely to be invaded. Younger forests, forests with non-forest patches present, and forests rich in native species were more likely to be colonized by exotic (invasive or non-invasive) plants. Frangula alnus, which is starting to spread locally, differed from the other invasive exotic species in terms of its association with high sapling density to tree density ratios, high soil nitrogen levels, and the presence of fire. Variables representing mortality due to beech bark disease and distance to the nearest exotic planting manifested counterintuitive results. In both cases, the combined occurrence of mortality due to beech bark disease or a close (less than 500m away) known propagule source and the presence of an invasive or non-invasive exotic plant was rare. We encourage increased use of intensive sampling for FIA in the U.S.A. and similar monitoring programs in other countries, but suggest adding a step to the plot selection phase that would allow forest-wide or regional stratified sampling of typically coarse-scale variables, such as historic or predicted defoliation or fire events, and forest or land type. A more accurate picture of the importance of disturbance variables in defining forest vulnerability to plant invasion may be achieved. [Copyright &y& Elsevier]