Pathways leading to apoptosis resistance in a murine B -cell lymphoma cell system

The aberrant activation of signal transduction pathways has long been linked to uncontrolled cell proliferation and the development of cancer. The activity of one such signaling module, the Mitogen-Activated Protein Kinase (MAPK) pathway, has been implicated in several cancer types including pancreatic, breast, colon, and lymphoid malignancies. Interestingly, the activation of MAP-Kinase-Kinase-Kinase proteins often leads to the additional activation of NF-κB, a transcription factor that acts as a cell survival signal through its control of antiapoptotic genes. We have investigated the role of a specific dimer form of the NF-κB transcription factor family, NF-κB1 (p50) homodimers, in its control of the proto-oncogene, Bcl-2, and we have identified the MEK/ERK (MAPK) signaling cascade as a mediator of NF-κB1 activity. ^ Two murine B cell lymphoma cell lines were used for these studies: LY-as, an apoptosis proficient line with low Bcl-2 protein expression and no nuclear NF-κB activity, and LY-ar, a nonapoptotic line with constitutive p50 homodimer activity and 30 times more Bcl-2 protein expression than LY-as. Experiments modulating p50 activity correlated the activation of p50 homodimers with Bcl-2 expression and additional gel shift experiments demonstrated that the Bcl-2 P1 promoter had NF-κB sites with which recombinant p50 was able to interact. In vitro transcription revealed that p50 enhanced the production of transcripts derived from the Bcl-2 P1 promoter. These data strongly suggest that Bcl-2 is a target gene for p50-mediated transcription and suggest that the activation of p50 homodimers contributes to the expression of Bcl-2 observed in LY-ar cells. ^ Studies of upstream MAPK pathways that could influence NF-κB activity demonstrated that LY-ar cells had phosphorylated ERK proteins while LY-as cells did not. Treatment of LY-ar cells with the MEK inhibitors PD 98059, U0126, and PD 184352 led to a loss of phosphorylated ERK, a reversal of nuclear p50 homodimer DNA binding, and a decrease in the amount of Bcl-2 protein expression. Similarly, the activation of the MEK/ERK pathway in LY-as cells by phorbol ester led to Bcl-2 expression that could be blocked by PD 98059. Furthermore, treatment of LY-ar cells with TNFα, an IKK activator, did not change the suppressive effect of PD 98059 on p50 homodimer activity, suggesting an IKK-independent pathway for p50 homodimer activation. Lastly, all three MEK inhibitors sensitized LY-ar cells to radiation-induced apoptosis. ^ These data indicate that the activation of the MEK/ERK MAP-Kinase signaling pathway acts upstream of p50 homodimer activation and Bcl-2 expression in this B cell lymphoma cell system and suggest that the activation of MEK/ERK may be a key step in the progression of lymphoma to advanced-staged disease. Other researchers have used MEK inhibitors to inhibit cell growth and sensitize a number of tumors to chemotherapies. In light of our data, MEK inhibitors may additionally be useful clinically to radiosensitize cancers of lymphoid origin. ^

Aprubt climate change events in the Northeastern Atlantic Ocean

The western Iberian margin has been one of the key locations to study abrupt glacial climate change and associated interhemispheric linkages. The regional variability in the response to those events is being studied by combining a multitude of published and new records. Looking at the trend from Marine Isotope Stage (MIS) 10 to 2, the planktic foraminifer data, conform with the alkenone record of Martrat et al. [2007], shows that abrupt climate change events, especially the Heinrich events, became more frequent and their impacts in general stronger during the last glacial cycle. However, there were two older periods with strong impacts on the Atlantic meridional overturning circulation (AMOC): the Heinrich-type event associated with Termination (T) IV and the one occurring during MIS 8 (269 to 265 ka). During the Heinrich stadials of the last glacial cycle, the polar front reached the northern Iberian margin (ca. 41°N), while the arctic front was located in the vicinity of 39°N. During all the glacial periods studied, there existed a boundary at the latter latitude, either the arctic front during extreme cold events or the subarctic front during less strong coolings or warmer glacials. Along with these fronts sea surface temperatures (SST) increased southward by about 1°C per one degree of latitude leading to steep temperature gradients in the eastern North Atlantic and pointing to a close vicinity between subpolar and subtropical waters. The southern Iberian margin was always bathed by subtropical water masses - surface and/ or subsurface ones -, but there were periods when these waters also penetrated northward to 40.6°N. Glacial hydrographic conditions were similar during MIS 2 and 4, but much different during MIS 6. MIS 6 was a warmer glacial with the polar front being located further to the north allowing the subtropical surface and subsurface waters to reach at minimum as far north as 40.6°N and resulting in relative stable conditions on the southern margin. In the vertical structure, the Greenland-type climate oscillations during the last glacial cycle were recorded down to 2465 m during the Heinrich stadials, i.e. slightly deeper than in the western basin. This deeper boundary is related to the admixing of Mediterranean Outflow Water, which also explains the better ventilation of the intermediate-depth water column on the Iberian margin. This compilation revealed that latitudinal, longitudinal and vertical gradients existed in the waters along the Iberian margin, i.e. in a relative restricted area, but sufficient paleo-data exists now to validate regional climate models for abrupt climate change events in the northeastern North Atlantic Ocean.

Coastal Urban Flood Resislience versus Climate Change

Processes of founding and expanding cities in coastal areas have undergone great changes over time driven by environmental conditions. Coastal settlements looked for places above flood levels and away from swamps and other wetlands whenever possible. As populations grew, cities were extending trying to avoid low and wet lands. No city has been able to limit its growth. The risk of flooding can never be eliminated, but only reduced to the extent possible. Flooding of coastal areas is today dramatically attributed to eustasic sea level rise caused by global climate change. This can be inaccurate. Current climate change is generating an average sea level upward trend, but other regional and local factors result in this trend being accentuated in some places or attenuated, and even reversed, in others. Then, the intensity and frequency of coastal flooding around the planet, although not so much as a unique result of this general eustasic elevation, but rather of the superposition of marine and crustal dynamic elements, the former also climate-related, which give rise to a temporary raising in average sea level in the short term. Since the Little Ice Age the planet has been suffering a global warming change leading to sea level rise. The idea of being too obeying to anthropogenic factors may be attributed to Arrhenius (1896), though it is of much later highlight after the sixties of the last century. Never before, the human factor had been able of such an influence on climate. However, other types of changes in sea levels became apparent, resulting from vertical movements of the crust, modifications of sea basins due to continents fracturing, drifting and coming together, or to different types of climate patterns. Coastal zones are then doubly susceptible to floods. Precipitation immediately triggers pluvial flooding. If it continues upland or when snow and glaciers melt eventually fluvial flooding can occur. The urban development presence represents modifying factors. Additional interference is caused by river and waste water drainage systems. Climate also influences sea levels in coastal areas, where tides as well as the structure and dynamic of the geoid and its crust come into play. From the sea, waters can flood and break or push back berms and other coastline borders. The sea level, controlling the mouth of the main channel of the basin's drainage system, is ultimately what governs flood levels. A temporary rise in sea level acts as a dam at the mouth. Even in absence of that global change, so, floods are likely going to increase in many urban coastal areas. Some kind of innovative methodologies and practices should be needed to get more flood resilience cities

Photodynamic therapy results in induction of WAF1/CIP1/P21 leading to cell cycle arrest and apoptosis

Photodynamic therapy (PDT) is a promising new modality that utilizes a combination of a photosensitizing chemical and visible light for the management of a variety of solid malignancies. The mechanism of PDT-mediated cell killing is not well defined. We investigated the involvement of cell cycle regulatory events during silicon phthalocyanine (Pc4)-PDT-mediated apoptosis in human epidermoid carcinoma cells A431. PDT resulted in apoptosis, inhibition of cell growth, and G0-G1 phase arrest of the cell cycle, in a time-dependent fashion. Western blot analysis revealed that PDT results in an induction of the cyclin kinase inhibitor WAF1/CIP1/p21, and a down-regulation of cyclin D1 and cyclin E, and their catalytic subunits cyclin-dependent kinase (cdk) 2 and cdk6. The treatment also resulted in a decrease in kinase activities associated with all the cdks and cyclins examined. PDT also resulted in (i) an increase in the binding of cyclin D1 and cdk6 toward WAF1/CIP1/p21, and (ii) a decrease in the binding of cyclin D1 toward cdk2 and cdk6. The binding of cyclin E and cdk2 toward WAF1/CIP1/p21, and of cyclin E toward cdk2 did not change by the treatment. These data suggest that PDT-mediated induction of WAF1/CIP1/p21 results in an imposition of artificial checkpoint at G1 → S transition thereby resulting in an arrest of cells in G0-G1 phase of the cell cycle through inhibition in the cdk2, cdk6, cyclin D1, and cyclin E. We suggest that this arrest is an irreversible process and the cells, unable to repair the damages, ultimately undergo apoptosis.

Paleoproterozoic snowball Earth: Extreme climatic and geochemical global change and its biological consequences

Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation (“snowball Earth” conditions) during Precambrian time. This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese. A Paleoproterozoic snowball Earth at 2.4 Giga-annum before present (Ga) immediately precedes the Kalahari Manganese Field in southern Africa, suggesting that this rapid and massive change in global climate was responsible for its deposition. As large quantities of O2 are needed to precipitate this Mn, photosystem II and oxygen radical protection mechanisms must have evolved before 2.4 Ga. This geochemical event may have triggered a compensatory evolutionary branching in the Fe/Mn superoxide dismutase enzyme, providing a Paleoproterozoic calibration point for studies of molecular evolution.

Shifts of Intracellular pH Distribution as a Part of the Signal Mechanism Leading to the Elicitation of Benzophenanthridine Alkaloids1 : Phytoalexin Biosynthesis in Cultured Cells of Eschscholtzia californica

Cultured cells of Eschscholtzia californica (Californian poppy) respond to a yeast elicitor preparation or Penicillium cyclopium spores with the production of benzophenanthridine alkaloids, which are potent phytoalexins. Confocal pH mapping with the probe carboxy-seminaphthorhodafluor-1-acetoxymethylester revealed characteristic shifts of the pH distribution in challenged cells: within a few minutes after elicitor contact a transient acidification of cytoplasmic and nuclear areas occurred in parallel with an increase of the vacuolar pH. The change of proton concentration in the vacuole and in the extravacuolar area showed a nearly constant relation, indicating an efflux of vacuolar protons into the cytosol. A 10-min treatment with 2 mm butyric or pivalic acid caused a transient acidification of the cytoplasm comparable to that observed after elicitor contact and also induced alkaloid biosynthesis. Experimental depletion of the vacuolar proton pool reversibly prevented both the elicitor-triggered pH shifts and the induction of alkaloid biosynthesis. pH shifts and induction of alkaloid biosynthesis showed a similar dependence on the elicitor concentration. Net efflux of K+, alkalinization of the outer medium, and browning of the cells were evoked only at higher elicitor concentrations. We suggest that transient acidification of the cytoplasm via efflux of vacuolar protons is both a necessary and sufficient step in the signal path toward biosynthesis of benzophenanthridine alkaloids in Californian poppy cells.

Societal transformation and climate change adaptation : PAR experiences in Portugal

Tese de doutoramento, Alterações Climáticas e Políticas de Desenvolvimento Sustentável (Sociologia), Universidade de Lisboa, Instituto de Ciências Sociais, 2016

Do the Genetic or Environmental Determinants of Anxiety and Depression Change with Age? A Longitudinal Study of Australian Twins

Because the determinants of anxiety and depression in late adolescence and early adulthood may differ from those in later life, we investigated the temporal stability and magnitude of genetic and environmental correlates of symptoms of anxiety and depression across the life span. Data were collected from a population-based Australian sample of 4364 complete twin pairs and 777 singletons aged 20 to 96 years who were followed-up over three studies between 1980 and 1996. Each study contained the 14-item self-report DSSI/sAD scale which was used to measure recently experienced symptoms of anxiety and depression. Symptom scores were then divided and assigned to age intervals according to each subject's age at time of participation. We fitted genetic simplex models to take into account the longitudinal nature of the data. For male anxiety and depression, the best fitting simplex models comprised a single genetic innovation at age 20 which was transmitted, and explained genetic variation in anxiety and depression at ages 30, 40, 50 and 60. Most of the lifetime genetic variation in female anxiety and depression could also be explained by innovations at age 20 which were transmitted to all other ages; however, there were also smaller age-dependent genetic innovations at 30 for anxiety and at 40 and 70 for depression. Although the genetic determinants of anxiety and depression appear relatively stable across the life-span for males and females, there is some evidence to support additional mid-life and late age gene action in females for depression. The fact that mid-life onset for anxiety occurs one decade before depression is also consistent with a causal relationship (anxiety leading to depression) between these conditions. These findings have significance for large scale depression prevention projects.

SubCM: A tool for improved visibility of software change in an industrial setting

Software Configuration Management is the discipline of managing large collections of software development artefacts from which software products are built. Software configuration management tools typically deal with artefacts at fine levels of granularity - such as individual source code files - and assist with coordination of changes to such artefacts. This paper describes a lightweight tool, designed to be used on top of a traditional file-based configuration management system. The add-on tool support enables users to flexibly define new hierarchical views of product structure, independent of the underlying artefact-repository structure. The tool extracts configuration and change data with respect to the user-defined hierarchy, leading to improved visibility of how individual subsystems have changed. The approach yields a range of new capabilities for build managers, and verification and validation teams. The paper includes a description of our experience using the tool in an organization that builds large embedded software systems.

The evolutionary history of Symbiodinium and scleractinian hosts - Symbiosis, diversity, and the effect of climate change

Marine invertebrates representing at least five phyla are symbiotic with dinoflagellates from the genus Symbiodinium. This group of single-celled protists was once considered to be a single pandemic species, Symbiodinium microadriaticum. Molecular investigations over the past 25 years have revealed, however, that Symbiodinium is a diverse group of organisms with at least eight (A-H) divergent clades that in turn contain multiple molecular subclade types. The diversity within this genus may subsequently determine the response of corals to normal and stressful conditions, leading to the proposal that the symbiosis may impart unusually rapid adaptation to environmental change by the metazoan host. These questions have added importance due to the critical challenges that corals and the reefs they build face as a consequence of current rapid climate change. This review outlines our current understanding of the diverse genus Symbiodinium and explores the ability of this genus and its symbioses to adapt to rapid environmental change. (c) 2006 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved.

Distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect

Conventional detection scheme for self-mixing sensors uses an integrated photodiode within the laser package to monitor the self mixing signal. This arrangement can be simplified by directly obtaining the self-mixing signals across the laser diode itself and omitting the photodiode. This work reports on a Vertical-Cavity Surface-Emitting Laser (VCSEL) based selfmixing sensor using the laser junction voltage to obtain the selfmixing signal. We show that the same information can be obtained with only minor changes to the extraction circuitry leading to potential cost saving with reductions in component costs and complexity and significant increase in bandwidth favoring high speed modulation. Experiments using both photo current and voltage detection were carried out and the results obtained show good agreement with the theory.

Envisioning innovation : the communication of technological change through graphic representation

Graphic depiction is an established method for academics to present concepts about theories of innovation. These expressions have been adopted by policy-makers, the media and businesses. However, there has been little research on the extent of their usage or effectiveness ex-academia. In addition, innovation theorists have ignored this area of study, despite the communication of information about innovation being acknowledged as a major determinant of success for corporate enterprise. The thesis explores some major themes in the theories of innovation and compares how graphics are used to represent them. The thesis examines the contribution of visual sociology and graphic theory to an investigation of a sample of graphics. The methodological focus is a modified content analysis. The following expressions are explored: check lists, matrices, maps and mapping in the management of innovation; models, flow charts, organisational charts and networks in the innovation process; and curves and cycles in the representation of performance and progress. The main conclusion is that academia is leading the way in usage as well as novelty. The graphic message is switching from prescription to description. The computerisation of graphics has created a major role for the information designer. It is recommended that use of the graphic representation of innovation should be increased in all domains, though it is conceded that its content and execution need to improve, too. Education of graphic 'producers', 'intermediaries' and 'consumers' will play a part in this, as will greater exploration of diversity, novelty and convention. Work has begun to tackle this and suggestions for future research are made.

Macro-level change and micro-level effects:a twenty year perspective on changing grocery shopping behaviour in Britain

In this paper we summarise key elements of retail change in Britain over a twenty-year period. The time period is that covered by a funded study into long-term change in grocery shopping habits in Portsmouth, England. The major empirical findings—to which we briefly allude—are reported elsewhere: the present task is to assess the wider context underlying that change. For example, it has frequently been stated that retailing in the UK is not as competitive as in other leading economies. As a result, the issue of consumer choice has become increasingly important politically. Concerns over concentration in the industry, new format development and market definition have been expressed by local planners, competition regulators and consumer groups. Macro level changes over time have also created market inequality in consumer opportunities at a local level—hence our decision to attempt a local-level study. Situational factors affecting consumer experiences over time at the local level involve the changing store choice sets available to particular consumers. Using actual consumer experiences thus becomes a yardstick for assessing the practical effectiveness of policy making. The paper demonstrates that choice at local level is driven by store use and that different levels of provision reflect real choice at the local level. Macro-level policy and ‘one size fits all’ approaches to regulation, it is argued, do not reflect the changing reality of grocery shopping. Accordingly, arguments for a more local and regional approach to regulation are made.

Constructing institutional change: emergence, contestation and convergence of business models in the field of Java application servers

How are innovative new business models established if organizations constantly compare themselves against existing criteria and expectations? The objective is to address this question from the perspective of innovators and their ability to redefine established expectations and evaluation criteria. The research questions ask whether there are discernible patterns of discursive action through which innovators theorize institutional change and what role such theorizations play for mobilizing support and realizing change projects. These questions are investigated through a case study on a critical area of enterprise computing software, Java application servers. In the present case, business practices and models were already well established among incumbents with critical market areas allocated to few dominant firms. Fringe players started experimenting with a new business approach of selling services around freely available opensource application servers. While most new players struggled, one new entrant succeeded in leading incumbents to adopt and compete on the new model. The case demonstrates that innovative and substantially new models and practices are established in organizational fields when innovators are able to refine expectations and evaluation criteria within an organisational field. The study addresses the theoretical paradox of embedded agency. Actors who are embedded in prevailing institutional logics and structures find it hard to perceive potentially disruptive opportunities that fall outside existing ways of doing things. Changing prevailing institutional logics and structures requires strategic and institutional work aimed at overcoming barriers to innovation. The study addresses this problem through the lens of (new) institutional theory. This discourse methodology traces the process through which innovators were able to establish a new social and business model in the field.

Entrepreneurship in transition economies:the role of institutions and generational change

The transition economies have lower rates of entrepreneurship than are observed in most developed and developing market economies. The difference is even more marked in the countries of the former Soviet Union than those of Central and Eastern Europe. We link these differences partly with the legacy of communist planning, which needs to be replaced with formal market-supporting institutions. But many of these developments have now taken place, yet entrepreneurial activity still remains low in many places. To analyse this longer term issue, we highlight the necessarily slow pace of development of new informal institutions and the corresponding social attitudes, notably rebuilding the generalised trust. We argue that changes are even slower in the former Soviet Union than Central and Eastern Europe because communist rule was much longer, leading to a lack of institutional memory. We posit that changes in informal institutions may be therefore delayed until after full generational change.