Perennial ryegrass (Lolium perenne L.) is commonly overseeded into hybrid bermudagrass [Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy] turfs during autumn in the southern United States. Overseeding can provide a green, actively-growing turf throughout the winter dormancy period. Improved persistence of perennial ryegrass cultivars has increased management inputs during the spring transition period. Lower input turf systems that provide acceptable winter overseeding quality are preferred, and research aimed at evaluating alternative overseeding species are warranted. Grooming reel attachments allowing for threedimensional clipping management (3DCM) have become increasingly used by turf managers for reducing grain and thatch, but scientific information on best management practices and canopy effects of 3DCM-grooming are lacking. A field study was conducted at the Texas A&M Turfgrass Field Laboratory in College Station, TX (30.6191 degrees N, 96.3576 degrees W), to investigate the effects of overseeding using annual (Lolium multiflorum Lam.) and perennial ryegrasses on 3DCM-groomed and non-groomed fairway turfs of 'Tifway' hybrid bermudagrass, zoysiagrass [Zoysia matrella (L.) Merr. 'Cavalier'], and seashore paspalum (Paspalum vaginatum Sw. 'Sea Isle 1'). The study was arranged as a randomized complete block split-split-plot with three replications. Species whole main plots were split into three grooming intervals, which were further split into four overseeding treatments. Data were collected assessing visual turf quality, visual turf cover, leaf area index, clipping yield, shoot density, and biomass partitioning. Results indicate annual ryegrass alone and an annual/perennial ryegrass overseeding mix provided acceptable turf quality, but did not improve turf recovery over perennial ryegrass alone in 'Tifway' or 'Sea Isle 1' turfs. In 'Cavalier' turfs, summer quality was affected by overseeding treatment as follows: control > annual > annual/perennial > perennial. The overseeding tolerance of the warm-season turfgrasses was as follows: 'Sea Isle 1' > 'Tifway' > 'Cavalier'. Differences in canopy architecture of warm-season turfgrasses were related to the overseeding tolerance of each species and used to explain plant competition during the spring transition period. Grooming by 3DCM improved late-season turf quality and reduced scalping in 'Tifway'. Overseeding establishment and canopy architecture were not affected by 3DCM.

Application of Certainty*, Manor*, Monument*, Revolver*, TranXit, Kerb*, and flazasulfuron in early June eliminated most ryegrass in one month with the onset of high summer temperatures. Certainty at 0.06 lb a.i./A, Manor at 0.012 lb a.i./A, Monument at 0.0047 lb a.i./A, Revolver at 0.008 lb a.i./A, TranXit at 0.0078 lb a.i./A, and flazasulfuron at 0.0039 lb a.i./A performed equivalent to higher rates to effectively remove ryegrass when applied in June. The herbicides at the lower rate range were not as effective in early May when ryegrass tended to regrow in cooler temperatures. Spring transition was achieved by applying higher rates of TranXit* at 0.031 lb a.i./A and flazasulfuron at 0.0156 lb a.i./A in early May to completely remove perennial ryegrass. Kerb at 1.0 lb a.i./A was effective in removing 80% of the ryegrass with a May application and 90% in June.

Thirteen herbicide treatments were applied on May 8, 2006, on a golf course fairway to assess transition and turf quality effects. Initial injury to perennial ryegrass was most extreme for Tranxit GTA when applied at 1.0 oz/prod/acre and Katana applied at 2.0 oz/prod/acre. Katana resulted in the total elimination of ryegrass and resulted in a fully necrotic canopy (straw cover) within two weeks after application to July 19, 2006 (72 Days after treatment). The development and persistence of necrotic leaf tissue of perennial ryegrass (straw) had the greatest impact on decreasing overall turfgrass quality ratings. No treatment went through the summer without some loss of quality at some point, including the untreated control. Certainty had little or no effect on transition when applied once at the rate of 1.25 oz/prod/acre. Surflan was not effective in ryegrass transition. The tank mix of Transit and nicosulfuron applied at the rate of 0.25 oz/prod./A each, produced an enhanced transition with nominal quality. In similar fashion, Monument applied at 0.35 oz./A produced an enhanced transition with nominal quality. A rates used in this test, other treatments had either too slow of a transition or had poor and extended low quality turf scores from rapid development of dead ryegrass (straw) and subsequent slow bermudagrass re-establishment. The UTC turf maintained a high percentage of living green ryegrass into the summer and 20% live ryegrass on August 8, 2006 which is roughly six weeks before the next overseeding.

La Méditerranée Nord-Occidentale (MNO) est marquée par un processus de formation d’eau profonde en hiver qui induit une forte floraison phytoplanctonique au printemps. L'objectif de cette thèse a été de caractériser la dynamique de la communauté mesozooplanctonique à l'échelle régionale de la MNO, y compris dans la zone de convection profonde (ZCP), en évaluant ses stocks, sa composition taxonomique, sa structure en taille et ses liens trophiques avec le phytoplancton, en relation avec l'environnement hydro-biogéochimique. Trois campagnes océanographiques ont été menées en saisons contrastées: hiver, printemps et été, fournissant un jeu de données unique à cette échelle régionale. Le zooplancton est caractérisé par de faibles abondances et biomasses en hiver, surtout dans la ZCP, puis par une augmentation générale printanière, en abondance et en biomasse. Des différences spatiales s’observent, la ZCP présentant les plus forts changements de biomasse de l’hiver au printemps. Les valeurs d'été sont similaires aux valeurs hivernales et sont assez homogènes dans la zone d'étude. L'impact du broutage estimé n'est pas suffisant pour contrôler globalement la floraison printanière. Cependant, au printemps, toute la MNO, à l'exception de la ZCP, subit un contrôle top-down du zooplancton sur le phytoplancton, tandis que dans la ZCP, les valeurs de chlorophylle-a restent élevées malgré la forte demande en carbone du zooplancton, ce qui indique un contrôle bottom-up. Cette étude montre que la ZCP est probablement une zone d'intense transfert d'énergie vers les niveaux trophiques supérieurs ainsi que d'export de matière organique en MNO. / The North-Western Mediterranean Sea (NWMS) is characterized by a deep water convection process in winter, which induces a large phytoplankton bloom. The main objective of this thesis was to characterize the dynamics of the mesozooplankton community at the regional scale of NWMS including the deep convection zone (DCZ), by assessing its stocks, taxonomy and size structure, and by evaluating its phytoplankton-zooplankton trophic links in connection to the hydrological and biogeochemical environment. Three oceanographic cruises were conducted to map the NWMS in contrasting seasons: winter, spring, and summer. This represents a unique data set of zooplankton at this regional scale. The NWMS was characterized in winter by low zooplankton abundance and biomass. In spring, a general increase was found. Spatially DCZ was characterized by lowest stocks in winter and the highest in spring. In summer, biomass and abundance were similar to winter values and were quite homogenous over the study area. The estimated zooplankton grazing impact was not sufficient to globally control the spring phytoplankton bloom. However, in spring, all areas except the DCZ incurred top-down control by zooplankton on the phytoplankton stock. In the DCZ, the chlorophyll-a values remained high despite the high zooplankton biomass and carbon demand, indicating a sustained bottom-up control. This study indicates that the deep convection zone is likely an area of both enhanced energy transfer to higher trophic levels and organic matter export in NWMS.

Diploma thesis "Prague Spring from the point of view of the transition theory" deals with the time period of "Prague Spring" and briefly also about the following year. The application of the methods of transition tries to show the next development of Czechoslovakia in case if the development hasn't had stopped by the intervention of troops of Warsaw Pact. There is a brief development of transitology there and then; three transition theories from significant authors discussing this topic are mentioned there. Further, the attitudes of reformers to the society in the year 1968 in Czechoslovakia, changes in the society itself and in the Communist Party are investigated there. A very important fact is the international situation and influence of states of the Soviet Block to reviving process and it representatives. The main chapter offers the possible future development of Czechoslovakia after the implementation transition theories. In the last part events from the year 1969 are mentioned. Two public polls bring closer the perception of Prague Spring after 25 and 30 years and its importance for the transition to democracy in 1989.