The Impacts of Shoreline Development on Shallow-Water Benthic Communities in the Patuxent River, MD

Natural coastal habitats throughout Chesapeake Bay are increasingly threatened with shoreline modification due to population growth and rising rates of development. The replacement of these natural coastlines with hardened structures such as seawalls (bulkheads) and stone revetments (riprap) not only compromises vegetation at the land-water interface, but also can influence several elements of local aquatic food webs. Effects of these alterations have been well-studied with respect to fish assemblages and intertidal communities, particularly in conjunction with larger-scale watershed development, and recently, interest has shifted toward investigation of the effects of shoreline development on subtidal benthic infaunal communities.This study evaluated the direct, local impacts of bulkhead and riprap compared to natural marsh shorelines, as well as the effects of sediment characteristics, predator abundance, and system-specific physical features on benthic infauna in the Patuxent River, Chesapeake Bay. Forty-five sites were divided among three shoreline types and distributed across three main river zones. At each site, a benthic infaunal suction sample (3-mm mesh), push-core sample (500-μm mesh), sediment samples, water-quality measurements, and trawls for predators were taken. Samples were sorted to determine density, diversity, and biomass of infaunal organisms. Data were assessed using an Information-Theoretic approach (AIC analysis) to determine the most influential variables, of those measured, on the infaunal community for two benthic data sets: 3-mm-suctions and 500-μm-cores. Results from these analyses on 3-mm samples suggested that shoreline type was the best predictor of diversity, while wave energy, sediment chlorophyll concentration, sediment type, and predator abundance best predicted density and biomass. Benthic responses within the 500-μm dataset were not strongly affected by shoreline type. Rather, responses were best predicted by sediment chlorophyll, wave energy, sediment type, predator abundance, and sediment organic carbon (TOC) content.Results indicate that, compared to other Bay tributaries, the Patuxent River is a relatively degraded system. The small range in long-term responses of Patuxent infauna from previous work provides a possible explanation as to why I was unable to see significant differences in infaunal response among shoreline types in the current study (i.e., there was little scope for change by shoreline in the system as a whole). However, I suggest that natural marsh habitats are healthier subsystems of the Patuxent River, due to the greater variety of infaunal feeding guilds and higher infaunal biomass observed at these compared to hardened sites. Higher predator abundance was associated with higher infaunal biomass at natural marsh sites in both size fractions, suggesting the bottom-up control of higher-trophic-level species in this system, as predators seek out suitable prey items. Given these observations, and the fact that influential variables such as wave energy, sediment nutrient and chlorophyll content, predator abundance, and sediment type may vary according to shoreline type, the replacement of natural shoreline with hardened structures will lead to complex changes in subtidal benthic communities in Chesapeake Bay tributaries and should be minimized to maintain qualities of the natural system

The Gap-Filling Role of Private Environmental Governance: A Case Study of Semiconductor Supply Chain Contracting

Three of the principal international agreements that govern various aspects of hazardous substances or wastes are not legally binding on American companies because the US Congress has not passed the requisite implementing legislation. The failure of American companies to meet or exceed the standards set forth in these agreements, although not legally mandated, could be detrimental to American businesses operating on the global stage. The American semiconductor industry responded to this potential disconnect by developing internal firm-specific standards that bind suppliers through supply chain agreements. This Note explores the phenomenon of private standard setting in the semiconductor industry, a prime example of private environmental governance. It seeks to explain how, if at all, private standard setting in the semiconductor industry reflects, undercuts, or fills gaps inherent in the law governing this area in the United States. After looking closely at these standards, this Note recommends two general approaches that will improve upon the current firm-specific toxics standards

Infra-red absorption spectra and molecular structure of triatomic molecules

This report is written as a résumé of investigations of infra -red absorption spectra of triatomic molecules carried out during tenure of a Senior Research Award. It might have been written in thesis form giving details of experimental and other work, but much of this has already been published, and copies of the papers have been sent the Department; these papers run into some hundred pages of print, and a thesis would merely form unnecessary repetition occupying almostdouble thib number of typewritten pages. A resume which brings together the results, and gives the now well established methods of interpreting infra -red absorption spectra of triatomic molecules, seems therefore the more satisfactory form for the report.Published work will be referred to as follows: 'Investigations in the Infra -Red Region of the Spectrum' (1). Part I (Froc. Roy. Soc., 1930, A, 130, 133). || (2). Part II. (ibis, 1930, A, 130, 142). || (3). Part III. (ibid, 1931, A, 132, 236). || (4). Part IV. (ibid, 1931, A, 132, 252). || (5). Part V. (ibid, 1932, A, 135, 375). || (6). Part VI. (ibid, 1932, A, 137, 622).- || (7). Fart VII. (ibid, 1932, A, 138, 531). || (8). Part VIII. (ibid, 1933, A, 140, 193). || (a). Part IX. (ibid, 1933, A, 142, 129). || (b). Part X (ibid, 1934, A, 145, 338). || (9). 'Infra -Red and Raman Bands of Carbon Dioxide, Carbonyl Sulphide, and Carbon Disulphide'. (Z. Physik, 1932, 79, 35). || (10). 'Molecular Configuration of N20.' (Phys. Rev., 1932, 39, 534). || (11). 'Infra -Red Absorption Spectrum of Nitrogen Dioxide'. || (Nature, 1933, 131, 239). (12). 'The Asymmetrical Rotator and its Infra -Red Spectrum'. (Trans. Faraday Soc., 1930, XXVI, 197). || (13). 'A Method of Eliminating Magnetic Disturbance of High Sensitivity Galvanometers'. (J. Sci. Inst., 1930, VII). || (14). 'Structure of Triatomic I.Iolecules'. A. B. D. Cassie (Nature, 1933, 131, 438). || (15). 'Investigations of the Infra -Red Absorption Spectra of Sulphur Dioxide, Carbon Disulphide, and Carbonyl Sulphide'. A thesis for the Ph.D. degree at London University, by A. B. D. Cassie, June 1931. || (16). 'Investigations in the Infra -Red Region of the Spectrum Part XI - The Absorption Spectrum and Molecular Configuration of Boron Trichioride, and the Effect of Strain on Plane Groups of the Type XYs. (Proc. Roy. Soc., 1935, A, 148, 87).This work has been published in collaboration with Mr. C. R. Bailey, Lecturer at University College, London, apart from references (13), (14), (15), and (16)

Unleashing Gen Y: Marketing Mars to Millennials

Space advocates need to engage Generation Y (born 1977-1999).This outreach is necessary to recruit the next generation of scientists and engineers to explore Mars. Space advocates in the non-profit, private, and government sectors need to use a combination of technical communication, marketing, and politics, to develop messages that resonate with Gen Y. Until now, space messages have been generated by and for college-educated white males; Gen Y is much more diverse, including as much as one third minorities. Young women, too, need to be reached. My research has shown that messages emphasizing technology, fun, humor, and opportunity are the best means of reaching the Gen Y audience of 60 million (US population is 300 million). The important things space advocates must avoid are talking down to this generation, making false promises, or expecting them to "wait their turn" before they can participate. This is the MTV generation! We need to find ways of engaging Gen Y now to build a future where human beings can live and work on the planet Mars. In addition to the messages themselves, advocates need to keep up with Gen Y' s social networking and use of iPods, cell phones, and the Internet. NASA and space advocacy groups can use these tools for "viral marketing," where young people share targeted space-related information via cell phones or the Internet because they like it. Overall, Gen Y is a socially dynamic and media-savvy group; advocates' space messages need to be sincere, creative, and placed in locations where Gen Y lives. Mars messages must be memorable

Direct and indirect impacts of shoreline development on shallow-water benthic communities in a depauperate estuarine system

Modification of natural coastlines is prevalent as human coastal populations swell and effects of global climate change become clearer. We investigated effects of shoreline hardening and environmental factors on benthic infauna and trophic structure in the Patuxent River, Maryland, a stressed mesohaline Chesapeake Bay tributary. We characterized differences in density, diversity, biomass, and trophic structure for large (\u3e3 mm) and small (\u3e500 μm) infauna adjacent to natural marsh, riprap, and bulkhead (i.e., seawall) shores throughout the river. Akaike information criterion model comparisons were used to assess the evidence for differences in benthic infaunal structure using primary (shoreline type) and secondary (e.g., sediment grain size, predator abundance) variables. There was strong evidence for secondary factors to explain reduced biomass of infauna adjacent to developed shorelines. For large infauna, evidence suggested that shorelines with riprap had reduced diversity, and with bulkhead had increased diversity. Increased wave energy and chlorophyll-a were associated with high densities for both size fractions riprap shorelines. Trends suggested high biomass and more carnivores, omnivores, and deposit feeders adjacent to natural marshes, compared to low biomass and more filter feeders at developed shorelines. While similar studies in lower Chesapeake Bay systems have shown clear effects of shoreline type on benthic communities, the extensive development in the Patuxent River may contribute to larger-scale stress, yet some shoreline-specific effects were detected. Non-parametric tests revealed differences in infaunal communities by shoreline type and river zone. Thus, the benthic community in this estuary is driven by local shoreline effects, as well as large-scale physical and biotic factors

‘No One Should Destroy the Forest\u27: Using photo-based vignette interviews to understand Kenyan teachers\u27 views of the environment

In the midst of the current environmental crisis, scientists, academics, authors, and politicians worldwide are urging citizens to create sustainable communities. However, there is little capability to build a sustainable society without an informed, active, and engaged populous. This requires more than just environmentally knowledgeable citizens. It requires a society that understands the principles of the environment and can also exemplify them in daily life. In order to create a more environmentally literate world, there has been a push for environmental education integrated into schools. This qualitative study sought to examine Kenyan teachers’ perspectives on the human–nature interaction by conducting vignette focus-group interviews. It is a subject not widely explored but vital for conservation not only in this area, but also other areas that seek to have an ecological informed populous. The vignettes were created using photographs and explanations of the photographs that the participants collected and emailed to the authors. For the focus-group vignette interviews, there were a total of 55 participants (30 females and 25 males). After InVivo analysis, we had 6 codes (resentment, pride, perils, blame, pragmatism, and self-interested) within 3 major themes. This study has implications for informing science education to combat these traditions of subjecting students to a science curriculum that demotes Kenyan cultural heritage and lifestyle. By incorporating local knowledge such as the ideas discussed in this paper into Kenyan science education, Kenyans can reach one of most challenging objectives of education, which is to produce children who are fundamentally aware of their environment

The initiator methionine tRNA drives cell migration and invasion leading to increased metastatic potential in melanoma

The cell's repertoire of transfer RNAs (tRNAs) has been linked to cancer. Recently, levels of the initiator methionine tRNA (tRNAiMet) in stromal fibroblasts have been shown to influence extracellular matrix (ECM) secretion to drive tumour growth and angiogenesis. Here we show that increased tRNAiMet within cancer cells does not influence tumour growth, but drives cell migration and invasion via a mechanism that is independent from ECM synthesis and dependent on α5β1 integrin and levels of the translation initiation ternary complex. In vivo and ex vivo migration (but not proliferation) of melanoblasts is significantly enhanced in transgenic mice which express additional copies of the tRNAiMet gene. We show that increased tRNAiMet in melanoma drives migratory, invasive behaviour and metastatic potential without affecting cell proliferation and primary tumour growth, and that expression of RNA polymerase III-associated genes (which drive tRNA expression) are elevated in metastases by comparison with primary tumours. Thus specific alterations to the cancer cell tRNA repertoire drive a migration/invasion programme that may lead to metastasis

Spontaneous Breakdown of Superhydrophobicity

In some cases water droplets can completely wet micro-structured superhydrophobic surfaces. The {\it dynamics} of this rapid process is analyzed by ultra-high-speed imaging. Depending on the scales of the micro-structure, the wetting fronts propagate smoothly and circularly or -- more interestingly -- in a {\it stepwise} manner, leading to a growing {\it square-shaped} wetted area: entering a new row perpendicular to the direction of front propagation takes milliseconds, whereas once this has happened, the row itself fills in microseconds ({\it ``zipping''})Comment: Accepted for publication in Physical Review Letter