Descriptiones specierum Expeditionis. A. Apertura Tentralis infra caput v. cerTicem sita. Ocelli nuUi. a. Fissurae laterales in capitis marginibus. 1. Corpus normale. Genus LINEUS, Sowerbj. antrorsum rotandatum. Apertura ventralis parva, mulio post ceiT-iceai sit& Long. bipedalis ; lat. 0-32 poU. Eab. in sinu insulae "Ousima ;" littorale sub lapidibus. 2. Apertura proboscidis infra caput. VALENCmiA, Quatref. 18. Valbncinia elegans. V. annulata, St. (non Quatref.) L c. vii. 380. Gracilis, fere linearis, supra convexa. Caput breve, paullo latius quam corpus, late truncato, fronte in medio sinuata, lateribus rotundatis. Corpus supra purpureo-fuscum, trilineatum ; lineis albis, mediana antice in fronte, lateralibus post cervicem incipientibus ; et fasciis transversis albis ad 16 annulatum. Caput fascia postfrontali pallide fusca. Long. 3 ; corporis lat. 0-08 poU. Hab. Prope Promontorium Bonse Spei ; inter algas in fundo arenoso profunditatis 12 org. Tubulum membranaceum format. B. Apertura ventralis nulla. Ocelli duo vel plurimi. a. Fissurse v. fovese in capitis marginibus. DICHILUS, nov. gen. Corpus lineare depressum, longitudine mediocre. Caput corpori continuum subquadratum, plica transversa terminali bilabiatum ; labio inferiore emarginato. Ocelli duo subterminales. Cervix supra rimis obsoletis (pseudorimis) impressa. Maricolae. 20. DicHiLUS OBSCUKUS. Corpus supra pallide rubro-fulvum, maculis duabus oblongisin capite. Ocellifusci, sat magni, subdistantes, inmaculissiti. Pseudorimae cervicales tres ; una mediana longitudinalis, ez cujus medid aliae versug marginem utrinque oblique extendunt. Long. 3 ; lat. 0-08 poU. Hab. In portu insulae " Ousima ;" littoralis inter lapillos.

Redistribution of soil, nutrients, and contaminants is often driven by wind erosion in semiarid shrublands. Wind erosion depends on wind velocity (particularly during episodic, high-velocity winds) and on vegetation, which is generally sparse and spatially heterogeneous in semiarid ecosystems. Further, the vegetation cover can be rapidly and greatly altered due to disturbances, particularly fire. Few studies, however, have evaluated key temporal and spatial components of wind erosion with respect to (i) erosion rates on the scale of weeks as a function of episodic high-velocity winds, (ii) rates at unburned and burned sites, and (iii) within-site spatial heterogeneity in erosion. Measuring wind erosion in unburned and recently burned Chihuahuan desert shrubland, we found (i) weekly wind erosion was related more to daily peak wind velocities than to daily average velocities as consistent with our findings of a threshold wind velocity at approximately 7 m s(-1); (ii) greater erodibility in burned vs. unburned shrubland as indicated by erosion thresholds, aerodynamic roughness, and nearground soil movement; and (iii) burned shrubland lost soil from intercanopy and especially canopy patches in contrast to unburned shrubland, where soil accumulated in canopy patches. Our results are among the first to quantify post-fire wind erosion and highlight the importance of accounting for finer temporal and spatial variation in shrubland wind erosion. This finer-scale variation relates to semiarid land degradation, and is particularly relevant for predictions of contaminant resuspension and redistribution, both of which historically ignore finer-scale temporal and spatial variation in wind erosion.

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Normalized Difference Vegetation Index (NDVI) data were used to investigate vegetation changes after Hurricane Katrina (2005) for the Weeks Bay Reserve and surrounding area of coastal AL. Landsat 5 satellite images were acquired before landfall (March 24, 2005), after landfall (September 16, 2005), and 8 months after landfall (April 28, 2006). The March 2005 to September 2005 image comparison showed that average NDVI values decreased by 49% after landfall. Continuing into the next year, average NDVI values were −44% lower in April 2006 than they were in March 2005. Among habitat types, the estuarine emergent wetland experienced the largest average NDVI value decrease (−64%). The estuarine emergent wetland NDVI values continued to decrease by −27% from September 2005 to April 2006, whereas other habitats increased in NDVI.This continued suppression of NDVI values was attributed to increased salinity from the storm surge and to regional drought conditions that occurred after landfall. These results provide insight into the sensitivity of coastal vegetation from the interactions of both tropical cyclones and long-term environmental conditions.

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Temperature gradients that develop in ceramic materials during microwave heating are known to be strongly dependent on the applied microwave frequency. To gain a better understanding of this dependence, identical samples of ZnO powder compacts were microwave heated at three distinct widely separated frequencies of 2.45, 30, and 83 GHz and the core and surface temperatures were simultaneously monitored. At 2.45 GHz, the approximately uniform “volumetric” heating tends to raise the temperature of the sample as a whole, but the interior becomes hotter than the exterior because of heat loss from the surface. At 30 and 83 GHz, this interior to exterior temperature difference was found to be reversed, especially for high heating rates. This reversal resulted from increased energy deposition close to the sample's surface associated with reduced skin depth. A model for solving Maxwell's equations was incorporated into a newly developed two‐dimensional (2‐D) heat transport simulation code. The numerical simulations are in agreement with the experimental results. Simultaneous application of two or more widely separated frequencies is expected to allow electronic tailoring of the temperature profile during sintering.

Abstract. This study investigates the effects of human disturbance and environmental factors on the distribution of alien plant species on the Georgia Sea Islands (GSI), USA. We sampled the absolute cover of native and alien plant species on two tourist islands (St. Simons Island and Jekyll Island) and on two protected National Wildlife Refuge Islands (Blackbeard Island and Wassaw Island). On each island, vegetation composition and environmental variables (soil properties and salt spray) were measured in two habitats that differed substantially in their degree of environmental stress, the more exposed primary dune and the more sheltered and inland maritime forest. Sites were further stratified within each habitat into areas that had different levels of human disturbance. Many alien species were present on all islands and the absolute cover of alien species was not significantly different among islands even though they varied substantially in their degree of accessibility and overall land use. Alien plant cover was appreciably greater in severely disturbed sites than in less disturbed sites on all islands and within both habitats. However, the difference between disturbance categories was much less pronounced in the primary dunes where human disturbance agents do not mitigate the harsh environmental conditions of this habitat (salt spray and saline soils). Alien plant abundance on the GSI is evidently more dependent upon the availability of disturbed ground than the degree of accessibility or overall island development. It appears that human disturbance increases alien cover in general, but in environments where the stress levels are not mitigated, human disturbance does little to foster alien invasions.

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