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Plate tectonics is a fundamental factor in the sustained habitability of Earth, but its time of onset is unknown, with ages ranging from the Hadaean to Proterozoic eons1–3. Plate motion is a key diagnostic to distinguish between plate and stagnant-lid tectonics, but palaeomagnetic tests have been thwarted because the planet’s oldest extant rocks have been metamorphosed and/or deformed4. Herein, we report palaeointensity data from Hadaean-age to Mesoarchaean-age single detrital zircons bearing primary magnetite inclusions from the Barberton Greenstone Belt of South Africa5. These reveal a pattern of palaeointensities from the Eoarchaean (about 3.9 billion years ago (Ga)) to Mesoarchaean (about 3.3 Ga) eras that is nearly identical to that defined by primary magnetizations from the Jack Hills (JH; Western Australia)6,7, further demonstrating the recording fidelity of select detrital zircons. Moreover, palaeofield values are nearly constant between about 3.9 Ga and about 3.4 Ga. This indicates unvarying latitudes, an observation distinct from plate tectonics of the past 600 million years (Myr) but predicted by stagnant-lid convection. If life originated by the Eoarchaean8, and persisted to the occurrence of stromatolites half a billion years later9, it did so when Earth was in a stagnant-lid regime, without plate-tectonics-driven geochemical cycling.

The purpose of this instrumental, multisite case study is to examine fidelity, adaptation, and differentiation challenges found at Wood Badge, a nationwide Boy Scouts of America training for adult volunteer leaders. Our iterative analysis of more than 900 pages of fieldnotes and 400 pages of documents revealed facilitators often explicitly taught syllabus content during the trainings. Observers noted 119 minor differentiations across trainings, notably involving facilitator delivery methods and the duration and scheduling of training segments. Facilitators observed 16 adaptations, which appeared to be based on external conditions at trainings or facilitator preferences, and just three instances of differentiation. Our analysis of the trainings surfaced key fidelity/adaptation issues like overadherence, conflicting notions of deviation, and the impact of preparation on fidelity. In addition, we identified factors influencing facilitators’ use of adaptation and differentiation. Recommendations for large-scale trainings are made based on the study’s findings.

Adequate water pavement surface drainage on highways is crucial in minimizing the potential of hydroplaning. Highway cross slope has a significant effect of draining water laterally from the pavement surface. Currently, field surveying techniques and other manual measurement methods are used to collect cross slope data on a limited basis in most states, despite these methods being labor intensive and exposing personnel to traffic. Furthermore, field surveying techniques cannot provide continuous data and can only be conducted at sample-based locations. This study conducted a technical evaluation of the effectiveness of airborne LiDAR (light detection and ranging) scanning and mobile terrestrial LiDAR scanning systems in measuring pavement cross slopes. Cross slope data were extracted from the LiDAR point cloud at five selected test sections using two different methods: (i) end-to-end method using elevations only from the pavement edge lines to generate the cross slope; and (ii) 0.2 ft interval point extraction along the cross-section and using a fitted linear regression line as the basis for the cross slope. Cross slopes were also measured at test section locations using conventional surveying methods and compared with LiDAR-extracted cross slopes. Results demonstrate that LiDAR methods are reliable for collecting accurate pavement cross slopes and should be considered for the purpose of cross slope verification on a braod scale such as statewide to address cross slope and pavement surface drainage issues proactively.

Periodic measurement and identification of the presence and severity of pavement rutting are crucial for pavement management programs conducted by state transportation agencies. This paper proposes a novel analytical method for identifying pavement rutting locations using data collected by mobile terrestrial LiDAR scanning (MTLS). Four vendor MTLS systems were evaluated based on their ability to accurately reproduce a roadway’s transverse profile. To establish ground-truth measurements, 2 in. interval pavement transverse profiles, which included rutting sections, were collected using traditional surveying techniques. MTLS transverse profiles were evaluated using partial curve mapping, Fréchet distance, area, curve length, and dynamic time warping techniques. Resultant pavement transverse profiles were compared between vendors and a profile created from traditional surveying. Results indicate that calibrated MTLS systems can provide accurate transverse profiles for potential identification of pavement rut areas. Based on this determination, a novel method was developed for use in identifying locations of pavement rutting through analysis of the curvature of MTLS raster surfaces. After evaluating three grid cell sizes for elevation raster surfaces, a raster grid cell size of 1 ft × 1 ft was determined to be most suitable for identifying continuous concave raster cell groups along wheel path trajectories. These cell groupings were found to reliably identify pavement rutting locations. The analytical procedures employed through application of this method consist of an efficient workflow process that is not reliant on a time-consuming continuous comparison with an MTLS-modeled uniform surface.

ABSTRACTPlantago princepsvar. princepsis an endangered native Hawaiian plant, and part of the recovery plan includes repopulation using plants grown in a nursery. However, disease pressure from downy mildew is hindering repopulation efforts. The organism associated with the downy mildew was determined to be a Peronosporaspecies with brown, ellipsoid conidia measuring 21 by 16 µm on average, which was morphologically different from validly described species of Peronosporathat infect Plantagospecies, but it was morphologically similar to the invalidly published species Peronospora lanceolatae(Art. 40.1). Comparison of mitochondrial cytochrome oxidase subunit I (cox1), mitochondrial cytochrome oxidase subunit II (cox2), nuclear internal transcribed spacer (ITS), and nuclear 28S rRNA D1–D2 (28S) loci revealed the unknown Peronosporato be molecularly divergent from Peronospora altaand Peronsopora plantaginis, but very similar to Peronosporafrom Plantago lanceolata, the type host of P. lanceolatae. Phylogenetic trees inferred with maximum likelihood and Bayesian inference from a concatenated alignmaent and individual gene trees confirmed the divergence of the unknown Peronosporafrom P. altaand P. plantaginisand its similarity to P. lanceolatae. However, attempts to inoculate Plantago lanceolatawith the strain from Plantago princepsvar. princepswere unsuccessful, which, in conjunction with divergence in ITS, suggests that the unknown Peronosporais specific to Plantago princepsvar. princeps. Herein, the Peronosporastrain on Plantago princepsvar. princepsis described as the new species Peronospora kuewabased on morphology, molecular phylogenetics, and host specificity. In addition, Peronospora gaponenkoaeis described here to honor Nina Ivanova Gaponenko on the basis of her description of P. lanceolatae.

Over the past several years, traffic fatality rates in South Carolina have been consistently ranked among the highest in the country. Furthermore, South Carolina incurs an annual economic loss of over two billion dollars because of roadway traffic crashes. The South Carolina Department of Transportation, in collaboration with the South Carolina Department of Public Safety, has undertaken a series of initiatives to reduce the number of vehicle crashes, with a particular emphasis on injury and fatal crashes. One of these initiatives is the deployment of a map-based geocoded crash reporting system that has greatly improved the quality of crash location data. This paper provides an assessment of improvements in crash geocoding accuracy in South Carolina and how improved accuracy is beneficial to systematic statewide safety analysis. A case study approach is used to demonstrate practical applications and analysis techniques based on spatially accurate crash data. A survey of U.S. state highway agencies indicates that there are disparate crash reporting systems used across the country with regard to crash geocoding procedures and accuracies. Survey results indicate that not only does geocoded accuracy of crash locations vary by state, but accuracies often vary by jurisdiction within each state. Research results suggest that poorly geocoded crash data can bias certain types of safety analysis procedures and that many state safety initiatives, analysis methods, and outcomes can benefit from improving crash report geocoding procedures and accuracies.

The rise of the sharing economy in recent years led to changes in transportation service delivery, including the introduction of micromobility services. Case studies are needed to better understand determinants of micromobility mode choice and its impacts on transportation operations. This study used data from a micromobility pilot program in Birmingham, Alabama to analyze spatiotemporal demand variations and explore correlations between micromobility ridership and demographic characteristics and land use patterns. Using space-time pattern mining techniques, temporal and spatial variations in micromobility usage were confirmed, with peak usage observed on Fridays, Saturdays and Sundays, during afternoon and evening hours, and during warmer months. Spatial analysis employed Kernel Density techniques and revealed concentrated micromobility trip origins in high-density areas such as Railroad Park, downtown, the University of Alabama at Birmingham (UAB) campus, and the Five Points South neighborhood. Correlations between Birmingham micromobility ridership and demographic characteristics and land use patterns were studied using clustering approaches and a multilevel negative binomial model. The model identified significant positive associations between micromobility ridership and the younger population (18–34 years of age), with a negative association in the 45–54 age group, signaling a decline in usage among older individuals. Regarding land uses, the model results showed significant positive correlations with the presence of park areas and commercial, residential, and industrial land uses, and the university campus. Furthermore, a positive correlation was observed with the National Walkability Index and parking facilities, whereas increased distance from the city center was associated with reduced micromobility ridership. The study offers valuable insights that can assist decision and policymakers in Birmingham as well as other medium-sized cities, in planning, and implementing micromobility programs that serve the local needs.

ABSTRACTPrevious molecular phylogenetic studies have shown that families in Zoopagales are not monophyletic. To test the monophyly of genera and species in the order, we used a single-cell approach to generate nuclear 18S rRNA (18S) sequences for 10 isolates representing nine taxa. We provide the first sequences for the genus Zoopageand additional sequences for taxa in Cocholonema, Acaulopage, and Zoophagus. Our results reveal that Zoophagus, Zoopage, and Acaulopage tetracerosare not monophyletic. We conclude that morphology alone is not sufficient to delineate genera and species in the order and encourage studies that increase genetic sampling of taxa including type species.

Ensuring adequate pavement cross-slope on highways can improve driver safety by reducing the potential for ponding to occur or vehicles to hydroplane. Mobile laser scanning (MLS) systems provide a rapid, continuous, and cost-effective means of collecting accurate 3D coordinate data along a corridor in the form of a point cloud. This study provides an evaluation of MLS systems in terms of the accuracy and precision of collected cross-slope data and documentation of procedures needed to calibrate, collect, and process this data. Mobile light detection and ranging (LiDAR) data were collected by five different vendors on three roadway sections. The results indicate the difference between ground control adjusted and unadjusted LiDAR derived cross-slopes, and field surveying measurements less than 0.19% at a 95% confidence level. The unadjusted LiDAR data incorporated corrections from an integrated inertial measurement unit and high-accuracy real-time kinematic GPS, however it was not post-processed adjusted with ground control points. This level of accuracy meets suggested cross-slope accuracies for mobile measurements (±0.2%) and demonstrates that mobile LiDAR is a reliable method for cross-slope verification. Performing cross-slope verification can ensure existing pavement meets minimum cross-slope requirements, and conversely is useful in identifying roadway sections that do not meet minimum standards, which is more desirable than through crash reconnaissance where hydroplaning was evident. Adoption of MLS would enable the South Carolina Department of Transportation (SCDOT) to address cross-slope issues through efficient and accurate data collection methods.

The overall goal of this research was to identify proven successful safety programs used in other states and assess the potential for safety improvement if similar programs were implemented in South Carolina. The research team not only sought out engineering solutions, but also expanded the search to include programs for enforcement, education, licensing, legal proceedings, and emergency services—therefore incorporating a wide range of stakeholder groups. South Carolina has, for many years, had one of the highest mileage death rates of any state in the nation—far exceeding the national fatality rate. While South Carolina Department of Transportation has a federal requirement to develop and maintain the Strategic Highway Safety Plan, which identifies the state’s key safety needs and guides investment decisions toward strategies and countermeasures with the most potential to save lives and prevent injuries, South Carolina legislation and state policies have effectively blocked many paths to safety improvements. Tree protection ordinances, limited policies for graduated drivers licensing, bans on camera enforcement, and lack of universal helmet laws continue to undermine efforts to improve motor vehicle safety in the state. Using a data-driven approach to safety program selection will yield support for changes in programs, policies, and standards, and have positive impacts on safety, operational, and economic aspects of the South Carolina roadway system. Further, the implementation of a data-driven safety management program will help to assure that the most appropriate strategies are implemented. The successful implementation of this research would likely result in a substantial reduction in loss of life and injuries associated with motor vehicle crashes in the state of South Carolina.

AbstractIn response to a recent article in theKDP Record on recruiting teachers of color, the author explores a recruitment factor that the earlier article does not address: what students of color have already learned about teaching. Suggested changes for teacher education are offered.

ABSTRACTFood webs in temporary forest ponds are driven by decomposition of terrestrial inputs. Chytrid fungi are important components of the fungal community, degrading leaf litter in streams reliant on terrestrial inputs and in lake ecosystems where they may stabilize the food web. However, little is known about chytrid fungi in temporary forest ponds. We inventoried the chytrid diversity present in two temporary forest ponds via light microscopy of baited samples and ion semiconductor (Ion Torrent) sequencing of environmental DNA. We quantified trends of chytrid alpha and beta diversity as a function of spatial and temporal factors. A total of 59 chytrid taxa were detected throughout the study. Beta diversity exhibited variation across the sampled months for both the entire fungal community as well as for chytrids alone. Shifts in community composition were also apparent, although diversity metrics and composition patterns did not meet adjusted Pvalues. The results of this study highlight the diversity of chytrid fungi in temporary forest ponds and the need for further studies on the spatial and temporal dynamics of chytrid species.

The growth of bike share systems has increased opportunities for active transportation and recreation. Using Global positioning system data for all trips in two years for the Charleston, South Carolina bike share system, the objectives of the study were to 1) demonstrate a physical activity estimation process for bike share trips, 2) describe the estimated activity levels for the bike share system, and 3) examine differences in bike share physical activity levels by bike share membership type.

ABSTRACTThe authors explored military officers’ beliefs about stigma-related barriers to seeking mental health treatment. Participants (N= 190) included officers from the 4 major branches of service between the ranks of O-3 and O-6. Paired-sample ttests showed participants’ own beliefs about stigma-related barriers to mental health were more negative than their perceptions of peers’ beliefs. Scaled scores on personal beliefs about stigma-related barriers to seeking treatment were associated with willingness to seek help, while perceptions of peers’ beliefs were not. Implications on help seeking and stigma related to mental health are explored, as well as limitations and steps for future research.

Zoospore ultrastructural characters combined with molecular phylogenetic hypotheses have been used to revise the taxonomy of zoosporic true fungi. An example is the reclassification of Rhizophlyctis rosea-like fungal strains into four new families and three new genera within the order Rhizophlyctidales. One genus was Borealophlyctis, which included a Canadian isolate, DAOMC 229843. A recent survey of chytrid diversity in Alabama (USA) yielded additional strains (WJD 170, WJD 171) in the Borealophlyctislineage. With light and transmission-electron microscopy we examined strains DAOMC 229843, WJD 170 and WJD 171. We also analyzed partial nuc 28S rDNA D1-D3 domains (28S) and nuc rDNA region encompassing the internal transcribed spacers 1 and 2 and 5.8S (ITS) sequences to determine the phylogenetic placement of the strains within Rhizophlyctidales. Based on molecular divergence and morphological differences from the type Borealophlyctis paxensis, we recognize DAOMC 229843, WJD 170 and WJD 171 as representatives of the new species Borealophlyctis nickersoniae.

The article offers information on techniques for fabricating removable complete dentures. Topics include appointment with a dentist to discuss dental problem and establish a good rapport of understanding; objectives that should be fulfilled in several appointments related to fabrication of removable dentures; and integration of finished denture in fifth appointment.

This study evaluated the operational performance of two-way left-turn lanes (TWLTLs) of varying widths in urban and suburban settings, in support of more flexible lane width standards for the South Carolina Highway Design Manual (SCHDM) update. Currently, the SCHDM only allows a TWLTL width of 15 ft to be used in design, and the distribution of TWLTL widths observed in a field study were justly limited; this limitation disallowed a proper evaluation of operational effects of TWLTL width. A fully integrated, high-fidelity driving simulator was used to test the operational effects of a range of TWLTL widths. Sixty participants made a series of left turns from a development driveway into TWLTLs of various widths. The TWLTL simulator scenarios included three-lane and five-lane road cross-section configurations and TWLTL widths of 12, 14, and 16 ft. Analyses were performed to determine the effects of (a) TWLTL width on driver gap acceptance and (b) turning-vehicle encroachments into through lanes. Analysis of variance tests indicated that TWLTL widths of 12, 14, and 16 ft had no effect on gap acceptance for three-lane and five-lane roadway sections. Trajectories were compared for a random sample of participants to evaluate the effect of TWLTL widths on vehicle encroachments into through lanes. On the basis of a subset of 30 participants, only one encroachment was observed for the scenario with a width of 12 ft, and two encroachments for the scenarios with widths of 14 and 16 ft. Greater variation in lane position was observed for wider TWLTLs, as participants took advantage of the larger space for maneuvering.

The article discusses the standards set by schools in California to develop students who are trained and ready for employment. The author details the business and school partnership program, Visalia Partners in Education (VPIE) by the Visalia Unified School District of California, in developing profiles of student graduates for potential employment. Information on the partnerships between education, business and local governments to address skills gap is also mentioned.

Many chytrid phylogenies contain lineages representing a lone taxon or a few organisms. One such lineage in recent molecular phylogenies of Rhizophydiales contained two marine chytrids, Rhizophydium littoreumand Rhizophydium aestuarii. To better understand the relationship between these organisms, we increased sampling such that the R. littoreum/R. aestuariilineage included 10 strains of interest. To place this lineage in Rhizophydiales, we constructed a molecular phylogeny from partial nuc 28S rDNA D1–D3 domains (28S) of these and 80 additional strains in Rhizophydiales and examined thallus morphology and zoospore ultrastructure of our strains of interest. We also analyzed sequences of the nuc rDNA region encompassing the internal transcribed spacers 1 and 2, along with the 5.8S rDNA (ITS) of our 10 strains of interest to assess sequence similarity and phylogenetic placement of strains within the lineage. The 10 strains grouped together in three well supported clades: (i) Rhizophydium littoreum+ Phlyctochytrium mangrovei, (ii) three strains of Rhizophydium aestuariiand (iii) five previously unidentified strains. Light microscopic observations revealed four distinct thallus morphologies, and zoospore ultrastructural analyses revealed four distinct constellations of ultrastructural features. On the bases of morphological, ultrastructural and molecular evidence we place these strains in the new family Halomycetaceae and four new genera (Halomyces, Paludomyces, Ulkenomyces, Paranamyces) in Rhizophydiales.

Chytriomycesis a complex genus in Chytridiales. The morphological concept of the genus expanded as new taxa were added, and studies of zoospore ultrastructure and molecular phylogenies have revealed the genus to be polyphyletic. One problematic taxon is C. spinosusFay, a distinctive species characterized by whorls of spines on the zoosporangium and a large accumulation of vesicle material beneath the operculum. With light-, scanning-electron and transmission-electron microscopy, we examined a culture (WJD186) isolated from a muck sample collected from a temporary forest pond. We also analyzed the D1–D2 variable domains of the nuc 28S rDNA (28S) sequences to confirm the phylogenetic placement of the species relative to the type of Chytriomyces, C. hyalinusKarling. The morphology of culture WJD186 is consistent with features Fay described for C. spinosus, and the zoospore ultrastructure is consistent with the Group I-type zoospore characters of Chytriomycetaceae (Chytridiales). In our molecular phylogeny C. spinosusdoes not group with the type of Chytriomyces. Consequently, we erect a new genus in Chytriomycetaceae and present the new combination Fayochytriomyces spinosus.

Two 65-year-old white men with coronary heart disease, given niacin therapy for dyslipidemia for 5 months, developed intense dental and gingival pain that was associated with increases in dose and [...]

Defining and understanding traffic flow parameters within short-term Interstate work zones are crucial in developing effective policies to manage construction and maintenance work conducted on the nation's heavily traveled freeways. The South Carolina Department of Transportation (DOT) initiated a research study to develop a methodology for use in determining an updated lane closure policy for Interstate highway work zones. Phase 1 of the research was completed in May 2003, and findings identified threshold volumes for two-to-one lane closure work zone configurations. Phase 2 of the research further expanded numerically derived relationships and contained analysis of other short-term lane closure configurations including three-to-two and three-to-one lane closures. Both research phases concentrated on methods to determine the number of vehicles per lane per hour that can pass through short-term Interstate work zone lane closures with minimum or acceptable levels of delay as defined by South Carolina DOT. Phase 2 includes an expanded list of data collection sites with differing work zone characteristics. This paper presents the analysis and results of Phase 2 of the research. Headway analysis revealed that passenger car equivalents (PCEs) differed for various speed ranges and modified PCEs for various speed groups were applied in calculating capacity. A model for calculating work zone capacity that incorporates base capacity, PCEs for various speed groups, adjustment factors related to specific work zone characteristics, and number of lanes open through the work zone, is recommended.

The need to maintain adequate traffic flow through short-term Interstate work zones is paramount on today's heavily traveled freeways. Numerous states have policies related to traffic flow thresholds, vehicle delay, and vehicle queue lengths that provide guidance on conditions when shortterm lane closures can be instituted. Generally, traffic flow threshold limits are a function of traffic-stream characteristics, highway geometry, work zone location, type of construction activities, and work zone configuration. A research study was initiated in South Carolina to examine quantitatively the development and implementation of a methodology for use in determining an updated lane-closure policy based on statespecific parameters. The study focused on determining the number of vehicles per lane per hour that can pass through short-term Interstate work zone lane closures with minimal or acceptable levels of delay. Research tasks included a survey of policies of other states, field-data collection, and methodology development. A methodology was developed with field data collected from 22 work zone sites along South Carolina's Interstate system. Data were obtained during a 12-month period from September 2001 to August 2002. Data collection procedures and data analysis methods employed in model development are summarized. Results of this study may be helpful to state highway agencies interested in developing similar research-based policy guidelines for short-term Interstate lane closures in their jurisdictions.

The technology-driven, rapidly advancing field of spatial data and information science (SDIS) is an integral part of numerous engineering professions. Many college civil engineering programs are struggling to find ways to accommodate this subject in an already crowded undergraduate curriculum. There are several reasons that taking a course in SDIS is desirable for civil engineers entering today’s demanding job market. First, technologies related to surveying, spatial data, and information science are among the fastest developing in the industry, and there is significant demand for skills in the latest technology. Second, spatial data collection and analysis are essential to all civil engineering disciplines; thus, a fundamental understanding of data collection and analysis techniques is desirable. The transportation discipline of civil engineering may face the greatest need for professionals specializing in SDIS. Transportation planning, system design, facilities management, and transportation logistics rely heavily on SDIS technologies, including conventional surveying, geographic information systems, Global Positioning System, remote sensing, and digital terrain modeling. A description is given of a widely transferable and technically up-to-date course in geomatics that expands on traditional surveying by incorporating modern methods of spatial data collection, management, and analysis. Including a course on geomatics early in students’ undergraduate civil engineering curriculum may plant the seed for the development of future SDIS and SDIS for transportation professionals. Lessons learned in developing geomatics courses at Clemson University, Georgia Tech, and The Citadel are presented. Findings and recommendations are summarized with respect to broader application issues affecting the civil engineering curriculum.

1.Egg-laying behavior in the gastropodPleurobranchaea californica is a stereotyped sequence of events lasting several hours and culminating in the extrusion of eggs and their attachment to the substrate (Fig. 1). A hormone that causes egg laying has been localized in the two pedal ganglia by means of bioassay (Table 1). One fourth, but not one eighth, of a single pedal ganglion was capable of causing egg laying (Fig. 3).Pleurobranchaea egg-laying hormone differs from that of the closely related gastropodAplysia, sincePleurobranchaea egg-laying hormone did not cause egg laying inAplysia, nor didAplysia egg-laying hormone cause laying inPleurobranchaea.2.Pleubranchaea egg-laying hormone has a molecular weight of 4000–7000 daltons as determined by fractionation of pedal ganglia on Sephadex G-50 and subsequent bioassay of fractions (Fig. 4). The hormone stained with Coomassie blue when fractionated by SDS-polyacrylamide gel electrophoresis (Fig. 6), incorporated3H and14C labeled leucine when pedal ganglia were labeled in vitro (Figs. 7,8), and was inactivated by trypsin (Table 2). Therefore the hormone is presumably a polypeptide. The hormone was not inactivated by boiling (Table 3).3.Bioassay and gel electrophoresis localized the hormone to the medial lobe of the pedal ganglion (Fig. 6). Histology of the pedal ganglion revealed that the surface of the medial lobe is comprised exclusively of cells 70–90µm in diameter that stained with phloxine (Fig. 9b), a substance known to stain cells containing egg-laying hormone inAplysia (Fig. 9a) and other molluscs. Therefore, the medial lobe cells that stain with phloxine are presumably the site of synthesis and storage of egg-laying hormone.4.Whereas egg-laying hormone sufficient to cause egg laying is usally confined to the pedal ganglia, bioassay revealed hormone also in cerebropleural ganglia removed from animals in the act of laying eggs (Fig. 10). Extracts from cerebropleural ganglia of non-laying animals never caused egg laying (Table 1 and Fig. 10a), although these extracts did occasionally induce some of the components of egg-laying behavior (Fig. 10b). The greater amount of egg-laying hormone in cerebropleural ganglia of laying animals could signify the binding of hormone to target sites in this ganglion.

It is known that many house staff physicians are unable to demonstrate perfect metered dose inhaler (MDI) technique.

The physical ageing of polymethylmethacrylate is investigated using a combination of positron annihilation, dielectric relaxation and dynamic mechanical thermal analysis. Correlations are observed between the three types of observation; however, no simple theory can be seen to fit all of the data. The dielectric data indicates that ‘thermorheologically simplicity’ is probably not a valid assumption for this system. The data also suggest that the free volume distribution probably changes during ageing; however, it was not probably to quantify these changes from the current positron annihilation study. Comparison of the experimental data from these various techniques clearly indicates that processes occurring at a molecular level are complex and not simply the result of one single type of conformational rearrangement and have an apparent activation energy comparable to that of the glass-rubber transition. © 1997 Elsevier Science Ltd.

The effect of administration of terbutaline on the pulmonary and cardiovascular systems was studied in ten children with status asthmaticus. Terbutaline (0.01 to 0.04 mg/kg of body weight) was given subcutaneously in multiple doses. A significant decrease in respiratory rate and in arterial blood pressure, with no significant change in cardiac rate, was seen only after the first dose of terbutaline. There was a decrease in mean arterial carbon dioxide tension and an increase in mean arterial oxygen pressure. There was gross clinical improvement following administration of terbutaline in nine of the ten patients. One patient who failed to respond to administration of terbutaline also failed to respond to intravenously administered isoproterenol. We conclude that terbutaline is effective in the treatment of status asthmaticus, with only modest effects on the cardiovascular system.

1.Lobsters that are tethered in place on a treadmill (Fig. 3) walk against the direction of belt movement (Table 2). Forward and backward locomotion over the full range of step frequencies can be controlled by this method, even in the absence of visual input. The passive traction provided by a moving substrate is therefore an effective stimulus for walking and presumably operates in parallel with previously described optomotor pathways to provide positive feedback reinforcement of locomotory behavior.2.The movements (Figs. 1, 6) and muscular anatomy (Fig. 2) of a lobster walking leg are described. On the basis of simultaneous extracellular recording from several leg muscles (Fig. 5), and motion picture analysis, the overall patterns of joint movement and muscular coordination underlying forward and backward walking are described (Figs. 5, 6, 7).3.Some muscles that are synergic for forward walking are antagonistic for backward walking (Figs. 6, 7). Similarly movements that are synergic for lateral walking on the leading side are antagonistic for lateral walking on the trailing side (Fig. 6).4.Quantitative analysis of leg movements (Fig. 9) and electromyograms (Fig. 10) have shown that the walking muscles can be subdivided into three different functional classes: return stroke muscles, which exhibit bursts of relatively constant duration irrespective of step frequency (Fig. 10A); power stroke muscles in which burst duration varies linearly with step frequency (Fig. 10B); and bifunctional muscles, which exhibit the discharge characteristics of either return or power stroke muscles, depending on the direction of walking (Fig. 10C).5.Several lines of evidence (Table 3, Figs. 6, 7, 9, 10, 12) suggest that the limb elevator motoneurones (or their central antecedents) function as the central pacemaker of the walking system, and that other cyclic leg movements are appended to the basic elevation/depression cycle as appropriate to the direction of walking. Evidence is presented that proprioceptive inputs provided by passive traction are capable of controlling the direction of locomotion (Table 2), and determining the periodicity of stepping (Fig. 4), by altering the duration of powerstroke bursts (Figs. 9, 10, 15).

1.The dynamic properties of lobster walking leg reflexes were determined by quantitative analysis of the spike trains evoked by passive sinusoidal movements of single leg joints over a broad range of movement frequencies.2.The evoked reflexes follow movements as rapid as those which occur during normal locomotion (Figs. 3D, 4D, 5D, 6D, 7D, 8D) and thus exhibit the prerequisite property for modulation of locomotory output on a cycle by cycle basis.3.In most cases, the reflexes evoked by passive joint movement are selectively tuned to the joint movement velocities which characterize normal locomotion as determined by cinematography (Fig. 1, Table 1). Most inappropriate reflexes (i.e., reflexes which have no overt counterpart during locomotion) occur at different joint movement velocities than the normal locomotory movements.4.The coxo-basal depression movement and both thoraco-coxal joint movements evoke reflexes which are appropriate to serve as amplifiers of ongoing power stroke discharge during forward and backward walking (Fig. 9). Similarly, distributed and positive feedback reflexes resulting from the coxo-basal elevation movement are competent to both activate the appropriate coxal bifunctional muscle (Table 1), and augment ongoing return stroke discharge (Fig. 9).5.Most power stroke reflexes in bifunctional muscles are selectively tuned to low movement velocities (Table 1). It is suggested that this property makes them appropriate to function in load compensation.

The results of an interlaboratory comparison are reported for the lead isotope composition and for trace element concentrations in NIST SRM 1400 Bone Ash obtained using quadrupole and magnetic-sector inductively coupled plasma mass spectrometry (ICP-MS) and (for the Pb isotopes only) thermal ionization mass spectrometry (TIMS). Concentrations of 42 analytes, in addition to the 17 listed by NIST, are presented, including the rare earth elements. Twenty-six of these analytes are considered to have been reliably determined based upon the agreement of two or more laboratories, or based upon data from a single laboratory with consideration of the potential interferences. Nickel and cobalt were reliably determined only by medium-resolution magnetic-sector ICP-MS, or by quadrupole ICP-MS following matrix separation with an ion-exchange column. The Pb isotope composition reported here from TIMS agrees within 0.09% relative with previously reported, non-certified values for this standard reference material. The atomic abundances of²⁰⁸Pb, ²⁰⁷Pb and ²⁰⁶Pb determined by ICP-MS are statistically equivalent to the best-estimate TIMS values or differ statistically by 0.17% at most. The information provided in this paper will enhance the utility of this reference material.

The ca. 2.7–2.5 Ga Slave Province is a “granitegreenstone” terrane comprising deformed sedimentary and subordinate volcanic belts extensively intruded by granitoid rocks. The Nd isotopic data are reported for 58 samples of supracrustal and granitoid rocks exposed along a 400 km, east-west, transect at 65°N across the structural grain of the province. Initial ?Nd values reveal distinctly different crustal sources in the eastern compared to the western parts of the province, as expected from tectonic assembly of the province through accretion of juvenile crust to older continental crust. Supracrustal sequences (ca. 2.71–2.65 Ga) from the central and eastern parts of the province have positive ?Nd(1) values (+0.3 to +3.6), consistent with juvenile sources and formation remote from significantly older crust. Syn to late-deformation (ca. 2.63–2.60 Ga), mantle-derived diorites and related tonalites (type I) from the central and eastern parts of the province have similar initial ?Nd values (-0.1 to +2.7). In contrast, samples from the westernmost plutons, which intrude exposed pre-3.1 Ga crust, have much lower ?Nd(1) values (-1.0 to4.6) suggesting contamination of these magmas by older crust. The ?Nd(1) values of post-deformation granites (s.s.) (type II) also vary systematically across the province: values for granites west of longitude 110°30'W range from-0.2 to -5.3; those to the east range from +0.6 to +3.7. These data suggest mixed crustal sources dominated by Mid to Early Archean material (?Nd-2.6 to- 17 at 2.6 Ga) for the western granitoid rocks and juvenile sources for the eastern granites. The Nd isotopic data are consistent with the geology of the province in that exposures of Mid to Early Archean crustal rocks, predating the principal 2.7–2.5 Ga orogenic event are restricted to the western part of the province. The asymmetric pattern defined by the Nd isotopic data indicates the presence of distinct crustal rocks beneath the Slave Province. Similar isotopic variations observed across Phanerozoic collisional orogens have been interpreted to reflect tectonic assembly of crust by accretion of juvenile crustal terranes to an older continental margin. This process may also have been an important mechanism in the cratonization of the Slave Province.

Feeding behavior and the effect of its occurrence on other, unrelated behaviors were studied in the carnivorous marine gastropodPleurobranchaea calif arnica. The threshold of the feeding response is low and stable: it does not change in a circadian fashion (Fig. 1); it does not change during different behavioral states such as mating (Table 4) and quiescence (“sleep” Table 5); the threshold does not change following aversive electric shock to the oral veil (Table 1); and it does not change with repeated application of food stimuli (Fig. 2). In the present paper only two physiological variables were found to elevate the feeding response threshold; excessive mechanical stimulation (Figs. 3, 4) and satiation with food (Fig. 5).

1.Bilaterally paired ventral white cells (VWCs) in the buccal ganglion ofPleurobranchaea are putative command neurons which in part derive their ability to drive the neural network controlling the buccal mass from the progressive broadening of action potentials during repetitive firing (Fig. 1) (Gillette et al. 1978, 1980). We have conducted an investigation of the parameters and mechanisms of spike broadening using conventional intracellular recording methods, ion substitutions, intracellular injections, and pharmacological agents. In the course of these studies we found evidence for a role for [Ca++]i in modulating spike broadening.2.During a current-driven train of broadening spikes, the overshoot amplitudes initially increase progressively and then decline. The rate of broadening is slowest during growth of the overshoot and maximal during overshoot decline (Fig. 2), suggesting that changes in overshoot amplitude contribute to spike broadening. However, a continuous decline in spike undershoot amplitudes throughout the train suggests a relation between the factors underlying progressive spike broadening and progressive decline of undershoot (Fig. 3).3.Progressive spike broadening is dependent on the presence of external Ca++ (Fig. 4), indicating that late Ca++ current supports the prolonged depolarization of the broadened spike. In contrast, the progressive decay of the amplitudes of the K+-dependent undershoots is not dependent on external Ca++ (Fig. 5). Tetraethylammonium ion (TEA) applied extracellularly or injected intracellularly causes extreme spike prolongation (Fig. 6), indicating the presence of the delayed K+ current known to inactivate with depolarization in other molluscan neurons (Aldrich et al. 1979a). Both by analogy with a previous study of spike broadening (Aldrich et al. 1979b) and direct ly, these data suggest that spike broadening during repetitive firing is largely due to a progressive decrease in a delayed K+ current, which thus permits spike prolongation by inward Ca++ current.4.While the major contribution to spike broadening appears to arise from decrement of the TEA-sensitive K+ current, internal Ca++ levels appear to have a significant role in modulating the rate and extent of spike broadening. This role may be effected through a Ca++-activated K+ current (IK,Ca), and possibly by regulation of the Ca++ conductance itself.IK,Ca is demonstrable in the undershoots of single, unbroadened action potentials, whose waveforms and amplitudes are affected by agents and treatments known to suppressIK,Ca (low Ca++, Ba++, Co++, and injections of EGTA) or enhance it (high Ca++, high Ca++-buffer injection) (Figs. 7, 8, 9 and 10).5.Intracellular injection of the Ca++ chelator, EGTA, or replacement of external Ca++ by Ba++ enhances progressive spike broadening (Fig. 11). Conversely, intracellular injection of high Ca++ (EGTA) buffers suppresses broadening (Figs. 12 and 13). These experiments suggest a possible role for intracellular Ca++ regulation in modulating this form of functional neuronal plasticity (Fig. 14).

The metacerebral giant (MCG) neurons of the molluskPleurobranchaea have been analyzed using a wide range of methods (cobalt staining, histochemical, biophysical and electrophysiological) on several types of preparations (isolated nervous systems, semi-intact preparations, and behaving whole-animal preparations). The MCG is serotonergic. The bilaterally-symmetrical neurons have somata in the anterior brain. Each MCG neuron sends an axon out the ipsilateral mouth nerve of the brain and also into the ipsilateral cerebrobuccal connective which descends to the buccal ganglion. The descending axon sends one or more branches out most buccal nerves.

1.Unrelated acts of behavior inPleurobranchaea are organized into a behavioral hierarchy (Fig. 1), in which feeding behavior takes precedence over righting behavior and over withdrawal of the head and oral veil from tactile stimulation. The present paper examines the effect on the behavioral hierarchy of one form of experience that affects feeding motivation, namely, food satiation.2.Feeding specimens to satiation with raw squid increased the threshold of the feeding response measured using dilutions of squid homogenate (Fig. 4). These and the following effects of satiation were determined by comparing experimental (sated) to control (unsated) specimens using a “blind” experimental protocol, and were evident within minutes of satiation (Figs. 15, 16).3.Application of squid homogenate before and at various times after satiation suppressed righting behavior (Figs. 5, 6), whether or not feeding behavior occurred (Fig. 6).4.Strong tactile stimulation of the oral veil with a constant-strength mechanical stimulator (Fig. 2) caused withdrawal of the head and oral veil. This response remained constant over 10 trials repeated every 60 s (Fig. 3). In unsated specimens, the presentation of squid homogenate reduced the withdrawal response to 50–75% of control values (Figs. 7, 9), providing a quantitative demonstration of the dominance of feeding over withdrawal. Application of squid homogenate at various times after satiation did not suppress withdrawal (Figs. 7, 9) unless active feeding behavior occurred (Figs. 8, 10).5.The data show that the usual dominance of feeding behavior over righting behavior is independent of feeding motivation and dependent only on the presence of chemosensory stimuli that cause feeding. In contrast, the usual dominance of feeding behavior over withdrawal is dependent on the execution of feeding behavior.6.These behavioral observations suggest a dual cellular mechanism for the dominant position of feeding in the behavioral hierarchy (Fig. 17): direct inhibition of subordinate behaviors by sensory pathways that cause the dominant behavior (in the case of feeding versus righting); and inhibition of subordinate behaviors by central neurons that control the dominant behavior (in the case of feeding versus withdrawal).

Physical ageing studies are reported on poly(methyl methacrylate) (PMMA) using positron annihilation lifetime spectroscopy (PALS), dielectric relaxation spectroscopy (DRS) and dynamic mechanical thermal analysis (DMTA). A comparison of the results obtained from these different techniques indicates that the assumption of thermorheological simplicity for physical ageing is most probably questionable. Physical ageing appears to be primarily concerned with a loss in the relaxation strength in the region below the glass transition temperature as monitored isothermally using DRS. Analysis of the ‘ageing rates’ obtained from these three very different types of observation indicates the possibility of a common molecular origin to the processes observed. © 1998 Society of Chemical Industry

Structural relaxation processes are reported in polystyrene as a function of ageing time using positron annihilation lifetime and Doppler broadening spectroscopy. Changes in the intensity, lifetimes and line shapes with increasing temperature for ortho positronium annihilation show an internal consistency between the two experiments and may be described in terms of a simple logarithmic decay process. The isochronous and isothermal ageing data show internal consistency and are best described by either a Narayanaswamy distribution or a double exponential fit of the data. The possible effects of charging during the isothermal decay measurements are explored and found to influence the short term decay behaviour. Measurements of the liquid phase are extrapolated to lower temperatures to allow estimation of the equilibrium lifetimes in the glassy phase. Changes in the lifetimes and the long time component of the intensity are interpreted as being indicative of the structural relaxation process; they are not influenced by the effects of charging and exhibit a good correlation with physical ageing behaviour as determined by other techniques. © 1998 SCI.

A norm, $ \vert\vert\;\vert\vert$ is said to be locally uniformly convex if $ \left\Vert {{x_n}} \right\Vert \to \left\Vert x \right\Vert$ $ \left\Vert {{x_n} + x} \right\Vert \to 2\left\Vert x \right\Vert$ in norm. It is shown that a Banach lattice has an (order) equivalent locally uniformly convex norm if and only if the lattice is order continuous. This result is used to reduce convergence theorems for (lattice-valued) positive martingales and submartingales to the scalar case.

Forty-eight children with known asthma (ranging in age from 2 to 16 years) were studied during an acute attack. Each received either terbutaline or epinephrine subcutaneously in a random double-blind fashion. Measurement of heart rate, respiratory rate, and systemic arterial systolic and diastolic blood pressures and careful clinical assessment of obstruction of the airway were made before and at 15, 30, and 60 minutes after the administration of the drugs. Appreciable and significant clinica] improvement was noted in 19 of the 24 patients in both groups and was of comparable magnitude. A small, but significant, increase in heart rate was noted in those patients requiring only one injection of terbutaline, suggesting that the drug's selectivity for the lung is relative, not absolute. The present study demonstrates that terbutaline is an effective bronchodilator drug in acute childhood asthma.

1.Complex behavior in the carnivorous marine gastropod Pleurobranchaea californica is described (Figs. 1–6).2.Situations requiring behavioral choice can be created by simultaneously delivering the stimuli for two different behavior patterns. In such situations feeding is elicited in preference to other behaviors, including sexual activity and righting responses.3.Two behaviors have been examined in detail, the withdrawal response to light and feeding. The withdrawal response habituates; correlated studies on the nervous system showed that the habituation has two causes, adaptation of the visual response (Figs. 8, 9) and habituation of the participating central pathways (Figs. 10–12). The central habituation is specific to pathways involving the visual input. Neuromuscular adaptation is not involved in the behavioral habituation.4.The sequence of muscular activity causing the rhythmic feeding movements was determined by cinematography (Fig. 14) as well as anatomical (Fig. 15) and electromyographic (Figs. 16, 17) methods. Central nerve cells were located which either excite or inhibit efferent outflow to the feeding apparatus (Figs. 21, 22).