Changes in Behavior, Movement, and Home Ranges of Largemouth Bass Following Large-scale Hydrilla Removal in Lake Seminole, Georgia

About 1,200 ha of hydrilla ( Hydrilla verticillata L.f. Royle) was eliminated in the Spring Creek embayment of Lake Seminole, Georgia, using a drip-delivery application of fluridone (1- methyl-3-phenyl-5-[3-(trifluoromethl) phenyl]-4(1H)-pyridinone) in 2000 and 2001. Two groups of 15 and 20 largemouth bass (Micropterus salmoides Lacepede) were implanted with 400-day radio tags in February 2000 and 2001 to determine changes in movement and behavior before and after hydrilla reduction.(PDF contains 8 pages.

Resistance to DDT of a Freshwater Alga

Author Institution: Department of Biology, Oberlin College, Oberlin, Ohio 44074The amount of chlorophyll, the oxygen evolution in the light, and the oxygen uptake in the dark by Chlamydomonas reinhardtii Dangeard are unaffected by exposure to 100-1,000 ppb DDT for 16-96 hours at 18°-22°C in inorganic basal medium with and without acetate in the medium. The growth rate and final cell density of Chlamydomonas reinhardtii Dangeard were identical in control and experimental cultures exposed to 1000 ppb DDT in the growth medium for nine days at 22°C

Sense-Making of Empirical Knowledge Management through Frames of Reference

This research aims to make sense of empirical perceptions of multidimensional complex KM (knowledge management) issues, through the construction of social cognitive structures such as frames of references. The objective of this study is to derive a set of empirically induced KM frames which may serve three purposes: to establish a set of frameworks for future research in perception congruency or misalignment of KM-related issues; to offer empirical insights to existing KM-related theoretical research models; and to bridge research gaps and inter-link cross-functional, cross-disciplinary perspectives. Our research fits broadly into four phases, with current progression halfway through the second phase. Focus group research, in the context of grounded theory approach, will be used as the main research strategy to induce and refine KM frames

Novel Rbfox2 isoforms associated with alternative exon usage in rat cortex and suprachiasmatic nucleus

Abstract Transcriptome diversity in adult neurons is partly mediated by RNA binding proteins (RBPs), including the RBFOX factors. RBFOX3/NeuN, a neuronal maturity marker, is strangely depleted in suprachiasmatic nucleus (SCN) neurons, and may be compensated by a change in Rbfox2 expression. In this study, we found no superficial changes in Rbfox2 expression in the SCN, but mRNA population analysis revealed a distinct SCN transcript profile that includes multiple novel Rbfox2 isoforms. Of eleven isoforms in SCN and cerebral cortex that exhibit exon variation across two protein domains, we found a 3-fold higher abundance of a novel (‘−12–40’) C-terminal domain (CTD)-variant in the SCN. This isoform embraces an alternative reading frame that imparts a 50% change in CTD protein sequence, and functional impairment of exon 7 exclusion activity in a RBFOX2-target, the L-type calcium channel gene, Cacna1c. We have also demonstrated functional correlates in SCN gene transcripts; inclusion of Cacna1c exon 7, and also exclusion of both NMDA receptor gene Grin1 exon 4, and Enah exon 12, all consistent with a change in SCN RBFOX activity. The demonstrated regional diversity of Rbfox2 in adult brain highlights the functional adaptability of this RBP, enabling neuronal specialization, and potentially responding to disease-related neuronal dysfunction

Root Diseases and Blister Rust Associated with Bark Beetles (Coleoptera: Scolytidae) in Western White Pine in Idaho

Root systems of western white pine, Pinus montieola Douglas, were excavated with explosives and examined for pathogens. Data were also recorded on portions of the crown killed by blister rust caused by Cronartium ribieola Fisch. Statistical tests revealed a significant association between the bark beetles Dendroetonus ponderosae Hopkins and Pityogenes fossifrons (LeConte), and the root pathogen Armillariella mellea. (Vah!. ex Fr.) Karst and between beetles and all root diseases. Ninety-two percent of the trees attacked by bark beetles had root diseases, and 97% had either root diseases or blister rust. A discriminant analysis correctly classified 88% of the sample trees into two categories, trees infested with D. ponderosae or trees not infested with D. ponderosae, using the variables age (stump), diameter at 1.3 m in height, and percentage of the primary roots infected with pathogens. Major pathogenic organisms isolated from the roots included A. mellea, Phaeolus sehweinitzii (Fr.) Pat., Resinicium bieolor (Fr.) Parm., Vertieicladiella spp., and a Europhium strain. A hypothetical sequence of host tree invasion by blister rust, followed by infection by root diseases, and finally attacks by bark beetles, is postulated

Are Worker\u27s Wages Driven by National or Local Factors?

Previous studies of the linkage of national and regional labor markets have focused on aggregate employment growth and migration. By focusing on the separate effects of national and regional labor market economic conditions on wages, this study differs from much of the previous literature. In particular, this paper will extend the previous literature in two key directions. First, it will explore whether local economic activity and location-specific amenities have different effects on metropolitan and nonmetropolitan area wages. Second, it will determine whether these effects on workers varied by education level between metro and nonmetro workers. These issues will be explored using 1988-1993 National Longitudinal Survey of Youth data merged with local labor market measures of amenities and economic conditions. In this preliminary draft, we explore the differential impact of amenities and local economic conditions on wages for metropolitan versus nonmetropolitan workers. Our findings suggest that there are differences in returns to human capital when comparing metro and nonmetro workers. Moreover, compensating differentials for location-specific amenities, and local labor market conditions also appear to depend on metropolitan versus nonmetropolitan residence. Future research will extend the model to consider addition variations for skilled and unskilled workers

Individual Characteristics, Spatial Labor Market Differences, and Amenity Influences on Nonmetro/Metro Migration Patterns

Previous studies of the linkage of national and regional labor markets have focused on aggregate employment growth and migration. By focusing on the separate effects of national and regional labor market economic conditions on wages, this study differs from much of the previous literature. In particular, this paper will extend the previous literature in two key directions. First, it will explore whether local economic activity and location-specific amenities have different effects on metropolitan and nonmetropolitan area wages. Second, it will determine how regional labor markets and locality amenities affect metro and non-metro migration of workers. These issues will be explored using 1979-1996 National Longitudinal Survey of Youth data merged with local labor market measures of amenities and economic conditions. In this preliminary draft, we explore the differential impact of amenities and local economic conditions on wages for metro versus non-metro workers in the 1988-1993 NLSY sample. Our findings suggest that there are differences in returns to human capital when comparing urban and rural workers. Moreover, compensating differentials for location-specific amenities and local labor market conditions also appear to depend on metro versus non-metro residence. Similarly, locality amenities and labor market conditions primarily influence both metro and non-metro migration decisions

RRS Discovery Cruise 243, 11th October to 22nd November 1999. Sensory Biology in the Deep-Sea: Anatomy, Physiology, and Molecular Biology

RRS Discovery cruise 243 had two principal objectives: to collect deep-sea animals for a variety of biological studies ranging from physiology to molecular biology, and to deploy benthic landers. The landers are described in Section 9.1, and the midwater and benthic trawling in Section 9.2. A complete list of the stations worked, with times, latitudes and longitudes, is given in Section 10, and a track chart for the whole cruise is shown in Section 11. Trawling was conducted first and foremost in order to provide specimens required for work associated with NERC grant GR3/B1212 “Analysis of light-induced interactions in the deep-sea: bioluminescence and its relation to vision, reflectance and fluorescence” to Professor Peter Herring, Dr Julian Partridge, and Dr Peter Shelton. Of equal importance to the success of the cruise, however, was the provision of biological samples for a range of inter-related studies. Descriptions of these studies are given in Section 9.3. Throughout the cruise a narrative (Section 6) was compiled to document, in diary format, the main scientific activities on board ship. It also records information about factors which affected work, such as the weather, and problems with equipment. The narrative is more or less a list of notes rather than proper prose, and was written during the cruise, documenting events as they were planned, as they unfolded, or after they had happened. In consequence, the tenses of verbs tend to vary in a haphazard way, for which I apologise. During the cruise, the Discovery “Rough Log” of biological specimens was maintained by Professor Peter Herring. A précis of some of the information from the Rough Log is incorporated into the narrative as a record of some of the most common, and some of the most unusual, animals that were collected. This is necessarily a biased record. Nevertheless, it may be useful to others planning or conducting similar cruises to the areas worked during D243, particularly those targeting the pelagic macrofauna. As the narrative shows, D243 was plagued by problems with the main winch. At one stage, early in the cruise, the severity of these problems made it likely that the cruise would have to be terminated prematurely, without any trawling having been undertaken. That this situation was reversed is due to the determination and hard work of the RVS technicians who were on board the ship. To them, Phil Taylor (RVS Technical Liaison Officer/TLO), Kevin Smith (RVS Mobilisation Officer/MO), Paul Duncan, and Rhys Roberts, we are much indebted: without their labours the cruise would not have succeeded in the way it ultimately did. Inevitably, the “science time” of the cruise was affected by the winch problems (see Section 8) and was contributory to a decision not to work the slope of the African continent, which had been part of the original cruise directive. This was, however, to some extent compensated by the generally stable weather conditions in the work area. Although we encountered conditions more extreme than are indicated in the ‘Africa Pilot’ for the region during October/November (anticipated average wind force 3), at no time was work stopped by poor weather. This in itself partly justifies the relatively long passage time to the work area. The main reason for working in the region, however, was the high diversity and abundance of midwater and benthic macrofauna in this region of upwelling and high surface water productivity. This, in combination with the trawling methods used, which included the use of the relatively large RMT25 net and a closing cod end on the RMT8 net, ensured that the requirements of the scientific personnel for specimens were well met. The scientific complement of the cruise consisted of 23 people, ranging from graduate students to professors, from five countries and eleven institutions. In addition, the cruise also hosted a team from the BBC Natural History Unit, who were on board to film for the “The Blue Planet”, a television series about the seas which is due for release in 2001. That this diverse group (who are listed, with their contact details, in Section 2) worked so well together, and were steadfastly cheerful firstly in the face of the winch problems, and later in the face of the relentlessness of trawling and catch processing, is very much to their credit. As Principal Scientist on D243 I am extremely grateful for their hard work and support in the run-up to the cruise, during the time at sea, and in its aftermath. In particular I would like to single out for thanks Ben Boorman and Nigel Merrett who, as scientific day and night watch leaders, ensured that the fishing and the supply of specimens continued without a break. D243 was also notable for one other event: it was Peter Herring’ last cruise before his retirement from the Southampton Oceanography Centre. Without a doubt, none of the participants on D243 would have been there but for Peter, such has been his impact on ocean going biology. Indeed, the format of D243 very much follows the successful formula developed by him on numerous previous cruises, including some to the Cape Verde region of the West African upwelling. If a cruise report can be dedicated, this is dedicated to him