Lantana: Current Management Status and Future Prospects

Crop Production/Industries,

Stimulating a Great Lakes Coastal Wetland Seed Bank using Portable Cofferdams: Implications for Habitat Rehabilitation

Coastal wetland seed banks exposed by low lake levels or through management actions fuel the reestablishment of emergent plant assemblages (i.e., wetland habitat) critical to Great Lakes aquatic biota. This project explored the effectiveness of using portable, water-filled cofferdams as a management tool to promote the natural growth of emergent vegetation from the seed bank in a Lake Erie coastal wetland. A series of dams stretching approximately 450 m was installed temporarily to isolate hydrologically a 10-ha corner of the Crane Creek wetland complex from Lake Erie. The test area was dewatered in 2004 to mimic a low-water year, and vegetation sampling characterized the wetland seed bank response at low, middle, and high elevations in areas open to and protected from bird and mammal herbivory. The nearly two-month drawdown stimulated a rapid seed-bank-driven response by 45 plant taxa. Herbivory had little effect on plant species richness, regardless of the location along an elevation gradient. Inundation contributed to the replacement of immature emergent plant species with submersed aquatic species after the dams failed and were removed prematurely. This study revealed a number of important issues that must be considered for effective long-term implementation of portable cofferdam technology to stimulate wetland seed banks, including duration of dewatering, product size, source of clean water, replacement of damaged dams, and regular maintenance. This technology is a potentially important tool in the arsenal used by resource managers seeking to rehabilitate the functions and values of Great Lakes coastal wetland habitats

Fish Assemblages, Connectivity, and Habitat Rehabilitation in a Diked Great Lakes Coastal Wetland Complex

Fish and plant assemblages in the highly modified Crane Creek coastal wetland complex of Lake Erie were sampled to characterize their spatial and seasonal patterns and to examine the implications of the hydrologic connection of diked wetland units to Lake Erie. Fyke netting captured 52 species and an abundance of fish in the Lake Erie–connected wetlands, but fewer than half of those species and much lower numbers and total masses of fish were captured in diked wetland units. Although all wetland units were immediately adjacent to Lake Erie, there were also pronounced differences in water quality and wetland vegetation between the hydrologically isolated and lake-connected wetlands. Large seasonal variations in fish assemblage composition and biomass were observed in connected wetland units but not in disconnected units. Reestablishment of hydrologic connectivity in diked wetland units would allow coastal Lake Erie fish to use these vegetated habitats seasonally, although connectivity does appear to pose some risks, such as the expansion of invasive plants and localized reductions in water quality. Periodic isolation and drawdown of the diked units could still be used to mimic intermediate levels of disturbance and manage invasive wetland vegetation

The two stories of the habitus/structure relation and the riddle of reflexivity: A meta‐theoretical reappraisal

This article argues that two key puzzles arising from the theories of Bourdieu are inter-related. One is the question of how Bourdieu analyses the relationship between structure and habitus, and the other is the place of reflexivity in Bourdieu's work. We contend that it is only by carefully analysing Bourdieu's theoretical structure to grasp the relationship between these elements that one can understand whether or not his work offers useful resources for analysing the relation between routine action and self-reflection. This paper argues that there are two narrations of the structure/habitus relation in Bourdieu's work, and that the concept of self-reflective subjectivity is a residual element of the first narration and does not appear in the second. We then contend that this residual and under-developed concept of self-reflective subjectivity should not be confused with Bourdieu's analysis of epistemic reflexivity. These moves allow us to contribute to ongoing debates about the relation between routine action and self-reflection by arguing that the concept of the “reflexive habitus” – which some have argued is characteristic of social agents in high/late modernity – is both conceptually confused and is not a logical extension of Bourdieu's theories. In this way we try to clear the ground for more productive ways of thinking about routine action and self-reflection

Modulation of the equilibrative nucleoside transporter by inhibitors of DNA synthesis.

Expression of the equilibrative, S-(p-nitrobenzyl)-6-thioinosine (NBMPR)-sensitive nucleoside transporter (es), a component of the nucleoside salvage pathway, was measured during unperturbed growth and following exposure to various antimetabolites at growth-inhibitory concentrations. The probe 5-(SAENTA-x8)-fluorescein is a highly modified form of adenosine incorporating a fluorescein molecule. It binds. with high affinity and specificity to the (es) nucleoside transporter at a 1:1 stoichiometry, allowing reliable estimates of es expression by flow cytometry. Using a dual labelling technique which combined the vital DNA dye Hoechst-33342 and 5-(SAENTA-x8)-fluorescein, we found that surface expression of es approximately doubled between G1 and G2 + M phases of the cell cycle. To address the question of whether es expression could be modulated in cells exposed to drugs which inhibit de novo synthesis of nucleotides, cells were exposed to antimetabolite drugs having different modes of action. Hydroxyurea and 5-fluorouracil (5-FU), which inhibit the de novo synthesis of DNA precursors, produced increases in the expression of es. In contrast, cytosine arabinoside (ara-C) and aphidicolin, which directly inhibit DNA synthesis, produced no significant increase in es expression. Thymidine (TdR), which is an allosteric inhibitor of ribonucleotide reductase that depletes dATP, dCTP and dGTP pools while repleting the dTTP pool, had no significant effect on es expression. These data suggest that surface expression of the es nucleoside transporter is regulated by a mechanism which is sensitive to the supply of deoxynucleotides. Because 5-FU (which specifically depletes dTTP pools) causes a large increase in expression whereas TdR (which depletes all precursors except dTTP) does not, this mechanism might be particularly sensitive to dTTP pools

A depolarization and attenuation experiment using the COMSTAR and CTS satellites

Monthly statistical data are presented on ground rainfall rate and attenuation of satellite downlinks at 11.7 GHz, 19.04 GHz, and 28.56 GHz and on cross-polarization isolation at 11.7 GHz. Regression equations for relating isolation to attenuation, attenuation to rain rate, and attenuation at one frequency to attenuation at another frequency are also included. Longer-term statistics are also presented and discussed

Establishment of a Spaceport Network Architecture

Since the beginning of the space age, the main actors in space exploration have been governmental agencies, enabling a privileged access to space, but with very restricted and rare missions. The last decade has seen the rise of space tourism, and the founding of ambitious private space mining companies, showing the beginnings of a new exploration era, that is based on a more generalized and regular access to space and which is not limited to the Earth's vicinity. However, the cost of launching sufficient mass into orbit to sustain these inspiring challenges is prohibitive, and the necessary infrastructures to support these missions is still lacking. To provide easy and affordable access into orbital and deep space destinations, there is the need to create a network of spaceports via specific waypoint locations coupled with the use of natural resources, or In Situ Resource Utilization (ISRU), to provide a more economical solution. As part of the International Space University Space Studies Program 2012, the international and intercultural team of Operations and Service Infrastructure for Space (OASIS) proposes an interdisciplinary answer to the problem of economical space access and transportation. This paper presents a summary of a detailed report [1] of the different phases of a project for developing a network of spaceports throughout the Solar System in a timeframe of 50 years. The requirements, functions, critical technologies and mission architecture of this network of spaceports are outlined in a roadmap of the important steps and phases. The economic and financial aspects are emphasized in order to allow a sustainable development of the network in a public-private partnership via the formation of an International Spaceport Authority (ISPA). The approach includes engineering, scientific, financial, legal, policy, and societal aspects. Team OASIS intends to provide guidelines to make the development of space transportation via a spaceports logistics network feasible, and believes that this pioneering effort will revolutionize space exploration, science and commerce, ultimately contributing to permanently expand humanity into space

Corticosterone mediates stress‐related increased intestinal permeability in a region‐specific manner

Background  Chronic psychological stress (CPS) is associated with increased intestinal epithelial permeability and visceral hyperalgesia. It is unknown whether corticosterone (CORT) plays a role in mediating alterations of epithelial permeability in response to CPS. Methods  Male rats were subjected to 1‐h water avoidance (WA) stress or subcutaneous CORT injection daily for 10 consecutive days in the presence or absence of corticoid receptor antagonist RU‐486. The visceromotor response (VMR) to colorectal distension (CRD) was measured. The in situ single‐pass intestinal perfusion was used to measure intestinal permeability in jejunum and colon simultaneously. Key Results  We observed significant decreases in the levels of glucocorticoid receptor (GR) and tight junction proteins in the colon, but not the jejunum in stressed rats. These changes were largely reproduced by serial CORT injections in control rats and were significantly reversed by RU‐486. Stressed and CORT‐injected rats demonstrated a threefold increase in permeability for PEG‐400 (MW) in colon, but not jejunum and significant increase in VMR to CRD, which was significantly reversed by RU‐486. In addition, no differences in permeability to PEG‐4000 and PEG‐35 000 were detected between control and WA groups. Conclusions & Inferences  Our findings indicate that CPS was associated with region‐specific decrease in epithelial tight junction protein levels in the colon, increased colon epithelial permeability to low molecular weight macromolecules which were largely reproduced by CORT treatment in control rats and prevented by RU‐486. These observations implicate a novel, region‐specific role for CORT as a mediator of CPS‐induced increased permeability to macromolecules across the colon epithelium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96296/1/nmo.12066.pd

The Experience of Mental Health Service Use For African American Mothers and Youth

Little is known about African American families’ experiences with mental health services. A purposive sample of 40 dyads of African American youth (aged 13 to 19) and their mothers participated in a cross-sectional qualitative research design using semi-structured interviews that elicited information about their past experiences and satisfaction with mental health services. Though rarely received, group and family therapy were perceived favorably. However, both mothers and youth reported dissatisfaction centered on medication and lack of professionalism, confidentiality, and concern by providers. The failure of mental health services providers to meet basic standards of quality and professionalism may explain the low rate of service use by African Americans