Life in oceans originated about 3.5 billion years ago where microbes were the only life form for two thirds of the planet’s existence. Apart from being abundant and diverse, marine microbes are involved in nearly all biogeochemical processes and are vital to sustain all life forms. With the overgrowing number of data arising from culture-independent studies, it became necessary to improve culturing techniques in order to obtain pure cultures of the environmentally significant bacteria to back up the findings and test hypotheses. Particularly in the ultra-oligotrophic Red Sea, the ubiquitous SAR11 bacteria has been reported to account for more than half of the surface bacterioplankton community. It is therefore highly likely that SAR11, and other microbial life that exists have developed special adaptations that enabled them to thrive successfully. Advances in conventional culturing have made it possible for abundant, unculturable marine bacteria to be grown in the lab. In this study, we analyzed the effectiveness of the media LNHM and AMS1 in isolating marine bacteria from the Red Sea, particularly members of the SAR11 clade. SAR11 strains obtained from this study AMS1, and belonged to subgroup 1a and phylotype 1a.3. We also obtained other interesting strains which should be followed up with in the future. In the long run, results from this study will enhance our knowledge of the pelagic ecosystem and allow the impacts of rising temperatures on marine life to be understood.

Humans used to be a part of nature, now we have become a force of nature. Our culture is based on infinite growth on a planet with finite resources. Its obvious that we need to change our lifestyle, in a radical way.Its not enough to drive a prius, buying organic food, or as an architect draw buildings with green roofs.We need a radical change of our lifestyle because we are facing radical change of our climate.Our impact is so great, occurs with such a speed and on a global scale that we have set of a mass extinction. My project consists of two parts.1: To apply a system, based on the unique properties of fungi, today.I want a site that is dead and polluted. 2: A site that will work as a testing ground, preparing us for a very harsh future. Alberta, CanadaOil sand mines the size of United Kingdom. Where a brutal mining process leaves a destroyed landscape behind. I see this landscape as a good preview of the future of our planet.I have formed a system that uses this extreme condition as an asset. The system will not only heal the landscape, it will also produce essential products such as food, fuel and material. All from fungi.The system is a network of fungi farms, growing through the land in patterns inspired by how fungi grows. / Människor brukade vara en del av naturen, nu har vi blivit en naturkatastrof. Vår kultur är baserad på evig tillväxt på en planet med begränsade tillgångar. Det är uppenbart att vi behöver ändra vår livsstil på ett radikalt sätt. För vi kommer snart att möta radikala ändringar av vårat klimat.   Svamp är en fascinerande livsform. Den var den första organismen att bosätta sig på jordens landmassor för 1.5 miljarder år sedan. Svamp kan leva utan ljus, kan leva i extremt förorenade miljöer och är en perfekt partner för att möta radikal klimat. Mitt projekt består av två delar. Att applicera ett system på oljesand gruvorna i Alberta, Kanada. Detta för att förbereda oss på en global ekologisk kollaps.

We explore the role of cooperativity and large deviations on a set of fundamental non-equilibrium many-body systems. In the cooperative asymmetric exclusion process, particles hop to the right at a constant rate only when the right neighboring site is vacant and hop at a faster rate when the left neighbor is occupied. In this model, a host of new heterogeneous density profile evolutions arise, including inverted shock waves and continuous compression waves. Cooperativity also drives the growth of complex networks via preferential attachment, where well-connected nodes are more likely to attract future connections. We introduce the mechanism of hindered redirection and show that it leads to network evolution by sublinear preferential attachment. We further show that no local growth rule can recreate superlinear preferential attachment. We also introduce enhanced redirection and show that the rule leads to networks with three unusual properties: (i) many macrohubs -- nodes whose degree is a finite fraction of the number of nodes in the network, (ii) a non-extensive degree distribution, and (iii) large fluctuations between different realizations of the growth process. We next examine large deviations in the diffusive capture model, where N diffusing predators initially all located at L 'chase' a diffusing prey initially at x<L. The prey survives if it reaches a haven at the origin without meeting any predator. We reduce the stochastic movement of the many predators to a deterministic trajectory of a single effective predator. Using optimized Monte Carlo techniques, we simulate up to 10^500 predators to confirm our analytic prediction that the prey survival probability S ~ N^-z^2, where z=x/L. Last, we quantify `survival of the scarcer' in two-species competition. In this model, individuals of two distinct species reproduce and engage in both intra-species and inter-species competition. Here a well-mixed population typically reaches a quasi steady state. We show that in this quasi-steady state the situation may arise where species A is less abundant than B but rare fluctuations make it more likely that species B first becomes extinct.

Few studies in the area of psychodietetics have concentrated upon the relationship between a single dietary nutrient and behavior. However, some vitamins have been shown to be particularly important to central nervous system activity. Among these is Vitamin C (ascorbic acid). Two experiments were done to determine the effects of ascorbic acid deficient diets on a learning task in which guinea pigs were subjects. Learning was defined as acquisition and extinction of shock-escape and shock-avoidance behavior. In Experiment I, twelve adult guinea pigs were fed diets containing two different deficient amounts of ascorbic acid for six weeks. They were then run on shock-escape, shock-avoidance and extinction schedules. No significant differences in behavior among the dietary groups were shown by statistical analysis, either in acquisition or extinction. In Experiment II, three adult guinea pigs were fed the same ascorbic acid-deficient diets as in Experiment I for six weeks after a baseline performance on a shuttlebox shock avoidance schedule was obtained. Performance after dietary treatment among or across subjects was not observably different from the performance prior to treatment. Serum and adrenal protein analysis confirmed that the dietary treatment had lowered the total ascorbic acid content of the serum and adrenals, but behavior did not show a corresponding or consistent change. These results indicate that ascorbic acid deficient diets fed to adult guinea pigs did not result in a change in behavior as observed on shock-escape, shock-avoidance, or extinction schedules.

The prediction of Capaldi's sequential learning theory (i966, 1967, 1970) that resistance to extinction (Rn) increases as a function of the number of successive nonrewarded trials (N-length) conditioned to the instrumental response has recently been supported in a discrete-trials leverpress situation but not in a free-operant leverpress situation (Wolach & Ferraro, 1971). To investigate this discrepancy, 32 male albino rats were trained to leverpress in the presence of a visual sD under one of two N-length conditions (8 or 16) and one of four intertrial interval (ITI) conditions (5, 10, 15, or 30 sec.), the lowest of which corresponded to a freeoperant interresponse time. A subsequent extinction phase revealed that the 16 N-length group displayed greater Rn than the 8 N-length group at each ITI investigated on the dependent measures of extinction speed (p is less than .01) and trials to extinction criterion (p is less than .05). The results were interpreted as supporting the applicability of sequential theory to both discrete-trials and free-operant methodologies.

The end–Triassic mass extinction event (ca. 201 Myr ago) has received particular attention over recent decades since Sepkoski (1981) classified it as one of the ‘‘big five’’ biotic crises in Earth's history. In the geological record of Greenland and Sweden, 80% of the species of terrestrial plants disappeared at this boundary. In the last two centuries, Triassic–Jurassic plant remains from Skåne, southern Sweden, have been collected, curated, and studied. However, the paleoflora from the lowermost part of the Helsingborg Member (Lower Jurassic: Hettangian) is poorly understood. Here, a taxonomic study is presented of two novel plant assemblages collected from the Boserup beds (basal Hettangian) in NorraAlbert Quarry, Skåne. The exposures in Skåne are among the few localities in the world that record the terrestrial ecosystem aftermath of the end–Triassic extinction event. Plant macrofossils were studied using macrophotography and fluorescence microscopy. The flora is composed of sphenophytes(Neocalamites), ferns (Cladophlebis, Eboracia), ginkgophytes (Czekanowskia, Pseudotorellia,Ginkgoites), and conifers (Pityophyllum, Brachyphyllum). These earliest Jurassic assemblages were deposited in floodplain environments and revealed a relatively low diversity of flora in the aftermath of the end-Triassic extinction but a fast recovery later. Additionally, the flora was compared with the relative lowermost Jurassic beds in East Greenland, Poland, and Germany, disclosing that ginkgophytes were widely distributed across the northern region of Pangea.

The peninsula effect is a pattern of diversity wherein species richness decreases along a peninsula from base to tip and is attributed to three mechanisms: historical processes, habitat gradients, and immigration-extinction equilibrium. Numerous studies have reported conflicting results involving the existence, cause, and validity of the peninsula effect in part because they did not account for effects of history or habitat on species richness patterns and because most previous research focused on organisms that actively disperse, which could confound results with behavioral habitat selection. Florida poses an excellent opportunity to study the peninsula effect because of its geological history and its unique ridges have similar histories (e.g. age, elevation, and sediment). Habitat changes down the peninsula, from a warm temperate climate in the north to a subtropical climate in the south. I studied freshwater crustaceans in isolated wetlands because crustaceans are diverse and disperse passively among these discrete habitats. My study design and statistical analyses controlled for two of the three mechanisms (habitat and history) that may generate a peninsula effect to better test for the third hypothesis (immigration-extinction equilibrium) on the Florida peninsula. Thirty-one wetlands were sampled for crustaceans monthly from November 2004 through April 2005, or until a site dried. Human disturbance was minimized by choosing isolated, ephemeral wetlands located within state reserves, parks, and forests located on four major ridges: Trail, Brooksville, Mount Dora and Lake Wales. I measured several environmental variables to assess habitat variation among sites. Limnological parameters included temperature, pH, dissolved oxygen, conductivity, chlorophyll á, pheophytin, total nitrogen, total phosphorus, and total hardness. Other habitat variables included surface area, distance to nearest water body, fish presence or absence, hydroperiod, total transmitted light and canopy openness. Crustacean species were identified to the lowest practical taxonomic level (typically species) and recorded as present or absent. A total of 53 different crustaceans were identified, including 41 cladocerans, 10 copepods, and 2 ostracods. In a multiple regression, environmental variables and sampling effort accounted for 57% of the variation in species richness. Regression of remaining variation (residuals) against latitude, which measures position along the peninsula, was not statistically significant. The same pattern was obtained when the sequence of regressions was reversed. Therefore, the peninsula effect does affect the species richness of freshwater crustaceans inhabiting ephemeral wetlands on Florida's ridges. Instead, variation in species richness was determined mainly by habitat differences, particularly the complex interaction of phosphorus levels, isolation, fish presence or absence, and hydroperiod. This study may serve as a model for more thorough analyses of mechanisms (history, habitat, and immigration-extinction) of a peninsula effect in other taxa.

Propulsion engine combustor design and analysis require experimentally verified data on the chemical kinetics of limiting fuel combustion rates. Among the important data is the combustion extinction limit as measured by the maximum global strain rate on a laminar, counterflow, non-premixed flame. The extinction limit relates to the ability to maintain combustor operation, and the extinction limit data for pure fuel versus air systems provide a relative reactivity scale for use in the design of flame holders. Extinction limit data were obtained for nine fuels by means of a laminar flame experiment using an opposed jet burner (OJB). The OJB consists of two axi-symmetric tubes (for fuel and oxidizer separately), which produce a flat, disk-like, counterflow diffusion flame. This paper presents results of experiments conducted in an OJB that measured extinction limits at one atmosphere for vaporized n-heptane, the Air Force-developed fuels JP-7, and JP-10, as well as methane, ethane, ethylene, propane, butane, and hydrogen. In hypersonic aircraft development it is desirable to design a Scramjet engine that is operated on hydrocarbon fuel, particularly JP-7 due to its distinct properties. This study provides key data for JP-7, for which very limited information previously existed. The interest in n-heptane is twofold. First, it has undergone a significant amount of previous flame structure and extinction limit study. Second, n-heptane (C7H16) is a pure substance, and therefore does not vary in composition, as does JP-7, which is a variable mixture of several different hydrocarbons. These two facts allow a baseline to be established by comparing the new OJB results to those previously taken. Additionally, the existing data for n-heptane, for mixtures up to 26 mole percent in nitrogen, is extended to 100% n-heptane, reaching an asymptotic limit. Extinction limit data for the two fuels are given with a comparison to hydrogen and several other gaseous hydrocarbon fuels. Complete experimental results are included. / Master of Science

<p> About half the Caribbean hermatypic corals died out at the Oligocene-Miocene boundary, about 25 Ma. Roughly two thirds of those corals which died out in the Caribbean are still extant in the Indo-Pacific. The coral and coral associate faunas of three Upper Oligocene and three Middle Miocene fossil reefs in western Puerto Rico were compared. Corals on these sites suffered 59% generic extinction, and 54% species extinction. Nearly all coral genera which are tolerant of turbidity or turbidity and cold water survived. All corals found exclusively or principally on Oligocene shelf-edge reefs became regionally extinct. There are no shelf-edge reefs documented from the Miocene in the Caribbean.</p> <p> Coral associates, the endolithic organisms which live in coral skeletons, were almost completely unaffected by this extinction. Likewise, reef and off-reef gastropods, bivalves, and echinoids suffered only insignificant reductions in diversity. Only corals and large benthic foraminifera were strongly affected by the extinction. It is significant that zooxanthellate organisms were the primary victims of this extinction. There is no evidence to suggest effects at higher trophic levels.</p> <p> Paleontological evidence from corals, coral associates, and gastropods suggests enhanced upwelling in the Caribbean during the Miocene and Early Pliocene. This enhanced upwelling could account for the extinction by cooling Caribbean coastal surface waters and restricting reef development to on-shelf patch reefs, where corals would be subject to more intense sedimentation. Paleoceanographic models indicating West to East deep circulation through the Central American Seaway during the Miocene provide a mechanism for this enhanced upwelling.</p> <p> Life history characteristics may have influenced survivorship among the corals, but apparently had no effect on coral associates. Corals which brood their larvae survived in greater proportions than corals which broadcast. This pattern is opposite that observed in studies on molluscs and other invertebrates.</p> <p> This regional extinction was important in the division of a previously cosmopolitan reef fauna into the modern provincial faunas. Explaining this minor mass extinction may contribute to an understanding of the volatile record of reefs in the larger mass extinctions of the Phanerozoic.</p> / Thesis / Master of Science (MSc)

Indiana University-Purdue University Indianapolis (IUPUI) / The evolution of land plant root systems occurred stepwise throughout the Devonian, with the first evidence of complex root systems appearing in the mid-Givetian. This biological innovation provided an enhanced pathway for the transfer of terrestrial phosphorus (P) to the marine system via weathering and erosion. This enhancement is consistent with paleosol records and has led to hypotheses about the causes of marine eutrophication and mass extinctions during the Devonian. To gain insight into the transport of P between terrestrial and marine domains, presented here are geochemical records from a survey of Middle and Late Devonian lacustrine and near lacustrine sequences that span some of these key marine extinction intervals. Root innovation is hypothesized to have enhanced P delivery and results from multiple Devonian sequences from Euramerica show evidence of a net loss of P from terrestrial sources coincident with the appearance of early progymnosperms. Evidence from multiple Middle to Late Devonian sites (from Greenland and northern Scotland/Orkney), reveal a near-identical net loss of P. Nitrogen and Carbon isotopes from a subset of these lakes confirm elevated input of terrestrial plant material concurrent with P perturbations. Terrestrial P input appears to be episodic in nature, suggesting land plant expansion was driven by an external catalyst in the study region. All sites analyzed are temporally proximal to significant marine extinctions, including precise correlation with the Kačák extinction event and the two pulses associated with the Frasnian-Famennian (F/F) mass extinction. The episodic expansion of terrestrial plants appears to be tied to variations in regional and global climate, and in the case of the F/F extinction, also to atmospheric changes associated with large scale volcanism. Using P data presented here as an input into an Earth system model of the coupled C-N-P-O2-S biogeochemical cycles shows that globally scaled riverine phosphorus export during the Frasnian-Famennian mass extinction generates widespread marine anoxia consistent with the geologic record. While timing precludes land plants as an initiating mechanism in the F/F extinction, these results suggest they are implicated in every marine extinction event in the Mid to Late Devonian.