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Pylaiella littoralis is a brown alga with a cosmopolitan distribution. A free-living form of the alga fouls the beaches of Nahant, Massachusetts (USA). The amphipod Gammarus tigrinus is found within the floating drifts of algae. Gut contents confirmed that G. tigrinus consumed P. littoralis. Significantly, culture studies revealed that ingested P. littoralis survives and grows from fecal pellets produced by G. tigrinus. Also, inefficient grazing produced vegetative fragments that grew and survived. δ13C values for the amphipods and P. littoralis averaged −17.4 ‰ and −17.7 ‰, respectively, suggesting that G. tigrinus acquires most of its carbon from P. littoralis. [ABSTRACT FROM AUTHOR]

Premise: Mycoheterotrophic plants rely on fungi to obtain their carbon requirements. Recent experiments demonstrated the presence of endophytic bacteria associated with mycoheterotrophs. Although mycoheterotrophs show high specificity for their fungal partners, it is not known whether they also show high specificity for associated bacteria or whether the bacteria have a definite function in the symbiosis. Methods: Two 16S rRNA sequencing experiments were designed to explore endophytic microbial community composition and function in root ball fractions of the mycoheterotroph Pterospora andromedea (Ericaceae), and rhizosphere soil and control soil 5 m away from each plant. One experiment compared microbial assemblages in fractions of six plants to those in rhizosphere and control soil samples. Another experiment documented bacterial endophyte diversity in root balls of 97 plants from across North America. Results: Soil samples were similar in bacterial community structure but were significantly more diverse and less consistently structured than were bacterial communities within root balls. The proportion of endophytic bacterial species varied slightly but not their community composition despite differences in P. andromedea lineage, geography, conifer species, and fungi. Predictive metagenomic profiling of the endophytes in P. andromedea‐only root ball fractions showed many of the bacterial endophytes likely function in N‐metabolism and N‐fixation. Conclusions: Our results document a consistent and largely invariant community of endophytic bacteria in P. andromedea across biotic and abiotic environmental conditions at a continental scale. It is unknown what role these bacteria may play in the quad‐partite symbiotic network centered on P. andromedea; however, the predictive metagenomic profiling suggests a possible function in N‐metabolism or N‐fixation. Discovery of a ubiquitous community of endophytic bacteria with a putative function centered on N‐metabolism or N‐fixation could have a previously unrecognized impact on understanding of mycoheterotroph ecophysiology. [ABSTRACT FROM AUTHOR]

Significant population declines in Acropora cervicornis and A. palmata began in the 1970s and now exceed over 90%. The losses were caused by a combination of coral disease and bleaching, with possible contributions from other stressors, including pollution and predation. Reproduction in the wild by fragment regeneration and sexual recruitment is inadequate to offset population declines. Starting in 2007, the Coral Restoration Foundation™ evaluated the feasibility of outplanting A. cervicornis colonies to reefs in the Florida Keys to restore populations at sites where the species was previously abundant. Reported here are the results of 20 coral outplanting projects with each project defined as a cohort of colonies outplanted at the same time and location. Photogrammetric analysis and in situ monitoring (2007 to 2015) measured survivorship, growth, and condition of 2419 colonies. Survivorship was initially high but generally decreased after two years. Survivorship among projects based on colony counts ranged from 4% to 89% for seven cohorts monitored at least five years. Weibull survival models were used to estimate survivorship beyond the duration of the projects and ranged from approximately 0% to over 35% after five years and 0% to 10% after seven years. Growth rate averaged 10 cm/year during the first two years then plateaued in subsequent years. After four years, approximately one-third of surviving colonies were ≥ 50 cm in maximum diameter. Projects used three to sixteen different genotypes and significant differences did not occur in survivorship, condition, or growth. Restoration times for three reefs were calculated based on NOAA Recovery Plan (NRP) metrics (colony abundance and size) and the findings from projects reported here. Results support NRP conclusions that reducing stressors is required before significant population growth and recovery will occur. Until then, outplanting protects against local extinction and helps to maintain genetic diversity in the wild. [ABSTRACT FROM AUTHOR]

Recent declines in coral populations along the Florida reef tract have prompted the establishment of coral restoration programs which raise coral species, such as the threatened Acropora cervicornis, in nurseries ready for outplanting. Large numbers of nursery-reared coral colonies have been outplanted along the Florida reef tract in recent years, yet few studies have characterized benthic habitats that are considered optimal for colony survival. In 2016, we surveyed 23 A. cervicornis restoration sites, located at six different reefs in the upper Florida Keys. We examined the condition of the outplanted corals and quantified the benthic assemblages adjacent to the outplanted coral colonies. We found that where A. cervicornis survived for more than 1 year, the substrate significantly supported less brown macroalgae of the genus Dictyota than at sites where A. cervicornis had died. Coral survival was highest at sites with less than 15% Dictyota cover. These results suggest that the habitat conditions that supported Dictyota spp. were not conducive to A. cervicornis growth and survival. Restoration practitioners should avoid attaching nursery-raised corals to substrate with Dictyota spp. cover greater than 15%. [ABSTRACT FROM AUTHOR]

Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal “death caps” and “destroying angels”. Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii. [ABSTRACT FROM AUTHOR]

Rhizopogonspecies are ecologically significant ectomycorrhizal fungi in conifer ecosystems. The importance of this system merits the development and utilization of a more robust set of molecular markers specifically designed to evaluate their evolutionary ecology. Anonymous nuclear loci (ANL) were developed forR. subgenusAmylopogon. Members of this subgenus occur throughout the United States and are exclusive fungal symbionts associated withPterospora andromedea, a threatened mycoheterotrophic plant endemic to disjunct eastern and western regions of North America. Candidate ANL were developed from 454 shotgun pyrosequencing and assessed for positive amplification across targeted species, sequencing success, and recovery of phylogenetically informative sites. Ten ANL were successfully developed and were subsequently used to sequence representative taxa, herbaria holotype and paratype specimens inR. subgenusAmylopogon. Phylogenetic reconstructions were performed on individual and concatenated data sets by Bayesian inference and maximum likelihood methods. Phylogenetic analyses of these 10 ANL were compared with a phylogeny traditionally constructed using the universal fungal barcode nuc rDNA ITS1-5.8S-ITS2 region (ITS). The resulting ANL phylogeny was consistent with most of the species designations delineated by ITS. However, the ANL phylogeny provided much greater phylogenetic resolution, yielding new evidence for cryptic species within previously defined species ofR. subgenusAmylopogon. Additionally, the rooted ANL phylogeny provided an alternate topology to the ITS phylogeny, which inferred a novel set of evolutionary relationships not identified in prior phylogenetic studies. [ABSTRACT FROM PUBLISHER]

One of the deleterious effects of acute nerve agent exposure is the induction of status epilepticus (SE). If SE is not controlled effectively, it causes extensive brain damage. Here, we review the neuropathology observed after nerve agent-induced SE, as well as the ensuing pathophysiological, neurological, and behavioral alterations, with an emphasis on their time course and longevity. Limbic structures are particularly vulnerable to damage by nerve agent exposure. The basolateral amygdala (BLA), which appears to be a key site for seizure initiation upon exposure, suffers severe neuronal loss; however, GABAergic BLA interneurons display a delayed death, perhaps providing a window of opportunity for rescuing intervention. The end result is a long-term reduction of GABAergic activity in the BLA, with a concomitant increase in spontaneous excitatory activity; such pathophysiological alterations are not observed in the CA1 hippocampal area, despite the extensive neuronal loss. Hyperexcitability in the BLA may be at least in part responsible for the development of recurrent seizures and increased anxiety, while hippocampal damage may underlie the long-term memory impairments. Effective control of SE after nerve agent exposure, such that brain damage is also minimized, is paramount for preventing lasting neurological and behavioral deficits. [ABSTRACT FROM AUTHOR]

Amorphous Boron Nitride (a-BN) is an important starting material for the synthesis of cubic BN (c-BN). However, information on the synthesis methods and the characteristics of a-BN are not sufficiently discussed in the literature. The purpose of this study is to understand the conversion of precursor chemicals to a-BN and to illustrate the effects of starting material and heat treatment conditions on the formation and characteristics of a-BN. Boric acid (H3BO3) and melamine (C3H6N6) were used as starting materials and the starting composition range was selected to be between 1:1 and 6:1 molar ratios (H3BO3:C3H6N6). Two-step solid state reaction method was applied for the synthesis of a-BN: First heat-treatment at 200°C for 2 hours in air and the second heat treatment at selected temperatures for 3 hours in N2 gas atmosphere. To determine the condition region for the synthesis of a-BN, synthesized powders were characterized using Xray diffraction, Raman and FTIR spectroscopies which showed different sensitivity for detecting crystalline phase in the powders. The condition regions for the synthesis of a-BN were determined to be between 400°C and 600°C for the composition range of 1:1 and 1.5:1. Crystallization was observed at lower temperatures for the samples with higher H3BO3 content in the H3BO3-C3H6N6 system. [ABSTRACT FROM AUTHOR]

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The 1983-1984 Caribbean-wide mass mortality of the once ubiquitous long-spined sea urchin Diadema antillarum Philippi, 1845, is one of several factors considered responsible for coral reef change throughout the region. Unfortunately, there is a paucity of pre-mortality event density data for D. antillarum in the Florida Keys, making it difficult to determine pre-1983 population density levels. Results from surveys conducted during 1970-1973 in the lower Florida Keys, in shallow (<12 m) fore reef habitats, yielded relatively abundant and widespread D. antillarum densities in qualitative transects at five reefs prior to the 1983-1984 die-off. In quantitative surveys at one reef, Middle Sambo Reef in 1972, up to 7.9 individuals m-2 were recorded using quadrats in high-relief spur and groove habitat. A second mortality event in the Florida Keys, beginning in April 1991, again depressed urchin densities that had begun to recover from the 1983-1984 mass mortality. By 1992, D. antillarum densities (<0.01 nr2) were two orders of magnitude lower than pre-die-off estimates (range of 0.07-0.57 m-2 from several spur and groove reefs in the lower Florida Keys) and remained so through 2009. The pre-mortality echinoid density estimates detailed in the Florida Keys provide a baseline to compare with their current population status and should help inform managers about realistic recovery or restoration targets for D. antillarum. [ABSTRACT FROM AUTHOR]

The discovery that even small changes in extracellular acidity can alter the excitability of neuronal networks via activation of acid-sensing ion channels (ASICs) could have therapeutic application in a host of neurological and psychiatric illnesses. Recent evidence suggests that activation of ASIC1a, a subtype of ASICs that is widely distributed in the brain, is necessary for the expression of fear and anxiety. Antagonists of ASIC1a, therefore, have been proposed as a potential treatment for anxiety. The basolateral amygdala (BLA) is central to fear generation, and anxiety disorders are characterized by BLA hyperexcitability. To better understand the role of ASIC1a in anxiety, we attempted to provide a direct assessment of whether ASIC1a activation increases BLA excitability. In rat BLA slices, activation of ASIC1a by low pH or ammonium elicited inward currents in both interneurons and principal neurons, and increased spontaneous IPSCs recorded from principal cells significantly more than spontaneous EPSCs. Epileptiform activity induced by high potassium and low magnesium was suppressed by ammonium. Antagonism of ASIC1a decreased spontaneous IPSCs more than EPSCs, and increased the excitability of the BLA network, as reflected by the pronounced increase of evoked field potentials, suggesting that ASIC1a channels are active in the basal state. In vivo activation or blockade of ASIC1a in the BLA suppressed or increased, respectively, anxiety-like behavior. Thus, in the rat BLA, ASIC1a has an inhibitory and anxiolytic function. The discovery of positive ASIC1a modulators may hold promise for the treatment of anxiety disorders. [ABSTRACT FROM AUTHOR]

This study was a preliminary analysis of the genetic structure of the ectomycorrhizal species Russula discopus, tL pseudocarmecina and R. ochraceorivulosa with disjunct distributions in continental Africa and Madagascar. Phylogenetic analyses of the nuclear ITS1/5.8S/ITS2 region and the mitochondrial atp6 gene were performed with specimens from both locations for each species along with a suitable outgroup for each of the three taxa. Additional analyses of the ITS1/5.8S/ITS2 region using the African and Malagasy specimens and additional taxa in the genus Russula also were performed. R. pseudocarmecina and R. discopus both exhibited genetic structure as shown by a relatively high percentage difference in ITS and atp6 sequences, high bootstrap support for African or Malagasy groups and the presence of indels in the ITS sequence that are unique to either Africa or Madagascar. African and Malagasy groups of each species were more closely related to each other than to other taxa in Russula. Genetic structure also existed in populations of R. ochraceorivulosa, but bootstrap support was weaker than in the other two species. In addition, there was less sequence divergence in R. ochraceorivulosa and this species was the only one for which the same atp6 haplotype was found in both Africa and Madagascar. Reciprocal monophyly for all three species was consistent with the hypothesis that the same vicariance event may be responsible for the genetic structure observed here, although shorter branch lengths, lower bootstrap support and the presence of the same atp6 haplotype in Africa and Madagascar for R. ochraceorivulosa suggested slower evolutionary rates or geographical isolation after the other two taxa. In addition to the geological events that separated Africa and Madagascar, environmental changes during the Miocene or later might have had an effect on the distribution of these species. [ABSTRACT FROM AUTHOR]

Elaphomyces compleximurus sp. nov. and E. digitatus sp. nov. are described from the Pakaraima Mountains of Guyana. Macromorphological, micromorphological, habitat and DNA sequence data are provided for each new species. This is the first report of Elaphomyces ascomata associated with ectomycorrhizal members of the Fabaceae and also for the genus from the lowland South American tropics. [ABSTRACT FROM AUTHOR]

Copyright of International Online Journal of Educational Sciences is the property of International Online Journal of Educational Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more “traditional” stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation. [ABSTRACT FROM AUTHOR]

A phylogenetic analysis of Lactarius sect. Deliciosi was performed based on collections of all known species. Several samples of each species were included, originating from a wide geographic range. The two DNA regions we used (ITS and a part of the gene encoding glyceraldehyde-3-phosphate dehydrogenase) showed an incongruent phylogenetic signal. Much attention was paid to carefully observed macro-and micromorphological characters to draw taxonomic conclusions. We currently accept 38 taxa (31 species and seven varieties) in Lactarius sect. Deliciosi worldwide; four species are new to science. More sampling is needed to resolve the status of the North American varieties. Our knowledge of the Asian species in this section remains fragmentary. The monophyly of the section and its position within Lactarius subgenus Piperites, as proposed in recent morphology-based classification schemes, is confirmed. The intrasectional relationships however do not coincide with the color of the latex (as previously supposed). Intercontinental conspecificity is low in general. The name L. deliciosus is wrongfully applied in North and Central America and only two species seem to occur in both Asia and Europe. [ABSTRACT FROM AUTHOR]

The Russulales is one of 12 major lineages recently elucidated by molecular sequence data in the homobasidiomycetes. The order is morphologically most diverse, containing a remarkable variety of sporophore forms including resupinate, discoid, effused-reflexed, clavarioid, pileate, or gasteroid and hymenophore configurations from smooth, poroid, hydnoid, lamellate, to labyrinthoid. Functionally these fungi are primarily saprotrophs but others are ectomycorrhizal, root parasites and insect symbionts. A phylogenetic analysis of the nuclear 5.8S, ITS2 and large-subunit rDNA genes comprises the best information to date on relationships of taxa within the Russulales. Two large sister groups encompassing 11-13 major clades have been recovered within the Russulales. Based on molecular and morphological data 12 families and approximately 80 genera have been identified, although placement of many taxa has not yet been determined. The two clades containing ectomycorrhizal taxa, corresponding to the Russulaceae and the Albatrellaceae, represent the greatest diversity of sporophore morphologies. The primarily pileate lamellate family Russulaceae is nested with resupinate species and also contains pileate sequestrate, gasteroid annulate and pleurotoid forms. Albatrellaceae similarly contains resupinate poroid, pileate poroid and pileate labyrinthoid sporophores. Presence of gloeoplerous hyphae containing fluid that typically stains black in sulfoaldehyde compounds is a synapomorphy for the Russulales. Amyloid reactions in spore or hyphal walls that occur frequently throughout the Russulales often are perceived as an obvious synapomorphy but are inconsistent. Approaches including sequencing functional genes, analysis of gene expression and biochemical analysis across the entire order are needed. [ABSTRACT FROM AUTHOR]

• Russula brevipes is common ectomycorrhizal (EM) fungus that is associated with several hosts across temperate forest ecosystems. A previous study has demonstrated that substructuring across large geographic distances (1500 km) occurs in the western USA. • To examine genetic structure over a more localized scale, basidiocarps of Russula brevipes from three subpopulations, separated by distances of 230–1090 m, were collected over two consecutive years in an oak/pine woodland. Microsatellite loci were used to test for population differentiation both among subpopulations and by year. • No significant population differentiation was detected between subpopulations (θST = 0.01) or between years (θST = 0.01). Most loci were consistent with a Hardy–Weinburg equilibrium and 82% of the genets between seasons from similar sampling localities constituted new genotypes. • These results indicate that R. brevipes constitutes a randomly mating population with no genetic differentiation between locations or across successive fruiting seasons. [ABSTRACT FROM AUTHOR]

This article discusses various issues related to the folly of Coral Restoration Programs following natural disturbances in the Florida Keys National Marine Sanctuary (FKNMS). Coral reefs around the world have changed dramatically over the past few decades. At the present rate of destruction, reef ecosystems will likely suffer continued significant degradation, possibly to the point of irreversible decline. In FKNMS, one possible course of action is to attempt to restore all damaged and disturbed reefs to fully functional ecosystems at a rate resulting in no net loss of ecosystem value. To date, most coral reef restoration programs within the FKNMS have focused on the physical damage caused by humans, although there has also been a call for intervening and restoring reefs affected by natural disturbances.

Presents a study which documented the changes in nutrient fluxes associated with internal tidal bores arriving on Florida Keys coral reefs. Background of studies on the anthropogenic factors associated with reductions in herbivore populations and the input of dissolved nutrients to reef environments; Methods used; Characteristics of temperature variability across reef sites; Analysis of hydrography and nutrients; Estimates of nitrogen and phosphorus input.

Developmental dyslexia, characterized by unexplainecl difficulty in reading, is associated with behavioral deficits in phonological processing. Functional neuroimaging studies have shown a deficit in the neural mechanisms underlying phonological processing in children and adults with dyslexia. The present study examined whether behavioral remediation ameliorates these dysfunctional neural mechanisms in children with dyslexia. Functional MRI was performed on 20 children with dyslexia (8-12 years old) during phonological processing before and after a remediation program focused on auditory processing and oral language training. Behaviorally, training improved oral language and reading performance. Physiologically, children with dyslexia showed increased activity in multiple brain areas. Increases occurred in left temporo-parietal cortex and left inferior frontal gyrus, bringing brain activation in these regions closer to that seen in normal-reading children. Increased activity was observed also in right-hemisphere frontal and temporal regions and in the anterior cingulate gyrus. Children with dyslexia showed a correlation between the magnitude of increased activation in left temporo-parietal cortex and improvement in oral language ability. These results suggest that a partial remediation of language-processing deficits, resulting in improved reading, ameliorates disrupted function in brain regions associated with phonological processing and produces additional compensatory activation in other brain regions. [ABSTRACT FROM AUTHOR]

Concern about declining trends in coral reef habitats and reef fish stocks in the Florida Keys contributed to the implementation of a network of no-take marine protected areas in 1997. In support of the efforts of the Dry Tortugas National Park and Florida Keys National Marine Sanctuary to implement additional no-take areas in the Tortugas region in 2001, we expanded the scale of our fisheries independent monitoring program for coral reef fishes in the region. To provide a foundation for the habitat-based, stratified random sampling design of the program, we created a digital benthic habitat map of coral reef and hard-bottom habitats in a geographic information system by synthesizing data from bathymetric surveys, side-scan sonar imagery, aerial photogrammetry, existing habitat maps, and in situ visual surveys. Existing habitat maps prior to 1999 were limited to shallow-water (< 20 m depth) soft-sediment, coral reef, and hard-bottom habitats within Dry Tortugas National Park and did not include deeper areas such as the Tortugas Bank, now partially contained within no-take marine protected area boundaries. From diver observations made during the 1999 survey, we developed a classification scheme based on habitat relief and patchiness to describe nine hard-bottom and coral reef habitats encountered from 1-33 m depth. We provide estimates of area by habitat type for no-take marine protected areas in the Tortugas region. Updated information on the spatial distribution and characteristics of benthic habitats will be used to guide future monitoring, assessment, and management activities in the region. Significant data gaps still exist for the western area of the Florida Keys National Marine Sanctuary and are a priority for future research. [ABSTRACT FROM AUTHOR]

Summary • The spatial mapping of genets from sporocarps allows determination of the primary modes of reproduction of ectomycorrhizal fungi. The goals of this research were to determine the relative size, density, and persistence of genets of Russula brevipes , a late successional basidiomycete, in mature stands of lodgepole pine ( Pinus contorta ) and Sitka spruce ( Picea sitchensis ). • Sporocarps were mapped and genets were identified using species-specific hypervariable microsatellite markers. • Most of the sporocarps sampled in clumped aggregations were the same genet and occupied areas less than 3 m. The largest distance measured between two sporocarps of the same genet was 18 m. In local populations of R. brevipes associated with Sitka spruce, genets were comprised of largely related individuals, whereas in lodgepole pine, most genets appeared unrelated. • High genotypic diversity in Sitka spruce stands suggests frequent mating and recombination between local inhabitants from primary establishment of basidiospores. In lodgepole pine, fewer, unrelated genotypes of R. brevipes indicates that multiple sources of colonization arose from infrequent, long distance spore dispersal events. [ABSTRACT FROM AUTHOR]

In this preliminary study, the authors examine the research literature and schematic models associated with the so-called expert-novice paradigm in cognitive psychology. Using this broad base, they develop a model for rendering expertise in problem solving within the domain of economics. Three principles-based economic problems were posed to three academic economists and two novices in the domain. Responses were given verbally; they were recorded, then transcribed, and used by the authors to develop the model. The initial findings and results of this preliminary study indicate that this model effectively rendered both expert and novice problem solving in economics. [ABSTRACT FROM AUTHOR]

The article critiques the texts in high school U.S. history textbooks based on a review of the treatment of the Great Depression in sixteen recent texts. The reviewed texts failed to incorporate research of economists on the causes of the Great Depression and presented information to students, which has rejected by the economics profession. Moreover, the article suggests several strategies that social studies educators might adopt to improve the quality of economic analysis in textbook, in light the issues surrounding the quality of social studies textbook and the importance of textbooks as the primary teaching tools.

Examines the timing of recruitment and species composition in coral reef fishes. Two types of priority effects among coral reef fish assemblages; Construction of underwater reef habitat called Hydrolab; Importance of timing the recruitment of planktonic larvae; Effect of a residence on recruitment.

Ectomycorrhiza formation, survivability, and physiognomic characteristics were assessed for conifer seedlings encountered 1 and 2 years postfire in the Huck burn site near Grand Teton National Park. Pinus contorta Dougl. ex Loud. germinated and was abundant throughout the first growing season. Abies lasiocarpa (Hook.) Nutt. germinated during May and June but was rarely encountered by September. First-year survivorship of P. contorta seedlings was about 50% for east-facing burn and edge and west-facing burn treatments. Mortality was higher in thewest-facing edge treatment at about 64%. Pinus contorta seedlings collected in July and August had allocated approximately 75% more biomass to epicotyl production than to hypocotyl production, whereas by September seedlings had allocated 30--50% of their biomass to hypocotyls, regardless of site or treatment. Few or no ectomycorrhizae were formed until September. By September 100% of surviving seedlings were ectomycorrhizal. The number of ectomycorrhizae was positively correlated with the number of primary needles and the root/shoot ratio. Theseresults highlight the importance of mycorrhizae to conifer seedling survival during the initial growing season and point to alteration ofcarbon allocation as a primary mechanism affecting seedling survival. [ABSTRACT FROM AUTHOR]