Disembodied Existence and Personal Identity

Honors (Bachelor's)PhilosophyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/107790/1/markabus.pd

The Late Quaternary palaeoecological history of the Great Wold Valley

The paucity of polliniferous deposits on the British chalklands has left something of a vacuum in the known vegetational history of the British Isles. Conflicting ideas of the past landscape of the chalklands have been  presented by archaeologists (e.g. Clark, 1936) and botanists (e.g. Tansley, 1939; Pigott and Walters, 1954). The Tansleyan view, i.e. that the chalklands were forested until the Bronze Age, has held sway. Tansley suggested  that the dominant species were Quercus and Fraxinus. This was challenged by the view that Tilia may have been a dominant on basic soils (Merton, 1970). Such palaeoecological evidence as exists would suggest that  woodlands covered the southern chalklands prior to Bronze Age disturbance, thus vindicating the Tansleyan  school.In this thesis data from a site lying on the Yorkshire Wolds are presented. For the first time a broad spectrum of palaeoecological information is presented from a British Flandrian chalkland deposit. Pollen, bryophytes, plant  propagules and macrofossil remains, mollusc and insect data form the basis for an environmental  reconstruction of the major water catchment area of the Yorkshire Wolds.This is complemented by a study of modern analogue sites where a vegetation survey had been undertaken.  Plant propagules, molluscs and bryophytes from the surface soil and modern pollen rain (trapped over a one  year period) were collected from each site. These data were incorporated into statistical analyses to compare  the changes in the fossil data with the range of known analogue habitats (after Lamb, 1984).Willow Garth, an ancient carr woodland in the Great Wold Valley, yielded fossil-rich deposits from the late-glacial  and Flandrian periods. Although the sedimentary history of this site would appear to be incomplete,  an exceptionally detailed image of the palaeoecological history of this valley emerges. The transition from the  late-glacial fen and tundra to the Pre-Boreal forest occurred at c. 9200 B.P.. However, the progression towards the mixed woodland of the Boreal forests appears to have been interrupted by the activities of Mesolithic man. It  is suggested that Mesolithic hunter-gatherers were 'managing' the woodlands to maximise the carrying capacity  of their game. One consequence of this activity was to prevent the forest canopy from closing over the  chalk grassland. Calcicolous grassland species were present throughout this period suggesting that the local  chalk grassland may never have been totally shaded out. If this was the case the chalk grasslands around the  Great Wold Valley would be of considerably greater antiquity than is generally supposed.During the late-Neolithic and the Bronze Age there is abundant evidence of anthropogenic disturbance with the  presence of agricultural weed taxa and pollen of Cerealia. Chalk grassland species are also represented in  both the faunal and floral records from this period. Cattle probably grazed the fen and the local wetland flora  reached a peak of diversity. In early Saxon times the fen started to dry out and it is suggested that its land use  may have changed from a grazed fen to an osier bed at c. 1200 B.P

Interaction of the Streptomyces Wbl protein WhiD with the principal sigma factor σHrdB depends on the WhiD [4Fe-4S] cluster

The bacterial protein WhiD belongs to the Wbl family of iron–sulfur [Fe-S] proteins present only in the actinomycetes. In Streptomyces coelicolor, it is required for the late stages of sporulation, but precisely how it functions is unknown. Here, we report results from in vitro and in vivo experiments with WhiD from Streptomyces venezuelae (SvWhiD), which differs from S. coelicolor WhiD (ScWhiD) only at the C terminus. We observed that, like ScWhiD and other Wbl proteins, SvWhiD binds a [4Fe-4S] cluster that is moderately sensitive to O2 and highly sensitive to nitric oxide (NO). However, although all previous studies have reported that Wbl proteins are monomers, we found that SvWhiD exists in a monomer–dimer equilibrium associated with its unusual C-terminal extension. Several Wbl proteins of Mycobacterium tuberculosis are known to interact with its principal sigma factor SigA. Using bacterial two-hybrid, gel filtration, and MS analyses, we demonstrate that SvWhiD interacts with domain 4 of the principal sigma factor of Streptomyces, σHrdB (σHrdB4). Using MS, we determined the dissociation constant (Kd) for the SvWhiD–σHrdB4 complex as ~0.7 μM, consistent with a relatively tight binding interaction. We found that complex formation was cluster dependent and that a reaction with NO, which was complete at 8–10 NO molecules per cluster, resulted in dissociation into the separate proteins. The SvWhiD [4Fe-4S] cluster was significantly less sensitive to reaction with O2 and NO when SvWhiD was bound to σHrdB4, consistent with protection of the cluster in the complex

The versatility of a truss mounted mobile transporter for in-space construction

The Mobile Transporter (MT) evolution from early erectable structures assembly activities is detailed. The MT operational features which are required to support astronauts performing on-orbit structure construction or spacecraft assembly functions are presented and discussed. Use of the MT to perform a variety of assembly functions is presented. Estimated EVA assembly times for a precision segmented reflector approximately 20 m in diameter are presented. The EVA/MT technique under study for construction of the reflector (and the entire spacecraft) is illustrated. Finally, the current status of development activities and test results involving the MT and Space Station structural assembly are presented

Why Economists Should Support Populist Antitrust Goals

Antitrust policy can be a powerful tool to tackle important social and economic problems. For decades antitrust enforcement has been shackled by the so-called Consumer Welfare Standard (“CWS”) that has limited the goals considered to be “legitimate.” The CWS limits antitrust goals to those that impact demand in markets, and primarily in output markets. Recently, new voices have come forward to suggest that antitrust policy should address several other important social objectives. Such goals include the traditional antitrust goals that motivated passage of the antitrust statutes, and which were discussed in Pre-Rehnquist Court opinions, including dispersion of economic and political power, and protection of small business. Additionally, it has been suggested that antitrust law should contribute to alleviating inequality, protecting labor when mergers occur or in the presence of monopsony, protect macroeconomic growth and stability when financial entities merge, and possibly contribute to efforts to advance sustainability. While some argue that the CWS is flexible enough to support some or all of these objectives, we disagree. There are at least five reasons why the CWS is severely limited or defective, preventing it from being an appropriate standard for modern antitrust. First (Section III below), it is a “material welfare” approach derived from Alfred Marshall, meaning an approach that cannot incorporate important issues that affect welfare such as political democracy and sustainability. This is made clear in the writings of Marshall and Pigou, the originators of the theory imported into antitrust by Judge Bork. Second (Section IV), the CWS assumes that the marginal utility of money (or the marginal social welfare with respect to a change in anyone’s surplus) is constant and equal among individuals impacted by anticompetitive practices. As a consequence, the CWS treats as inconsequential transfers of income between groups resulting from alleged restraints or mergers. Third (Section V), CWS is biased in favor of the wealthy, despite Section IV’s findings that CWS is neutral with respect to marginal transfers. Fourth (Section VI), CWS uses an indefensible measure of efficiency. Fifth (Section VII), CWS ignores the input market when analyzing restraints in the output market.We suggest that there are three questions that must be addressed when considering an antitrust criterion. First: is there credible social science research showing that the policy goals embodied in the criterion result in material increases in human well-being (the basis of economic welfare)? Second: can competition policy substantially advance the criterion? Finally, does the criterion provide a method for dealing with tradeoffs between the goals it embodies, if such tradeoffs are present? The CWS is so seriously limited that it does not even allow consideration of the first requirement. A more general welfare approach certainly can address the first two questions and may hold promise for satisfying the third

A Multi-perspective Analysis of Carrier-Grade NAT Deployment

As ISPs face IPv4 address scarcity they increasingly turn to network address translation (NAT) to accommodate the address needs of their customers. Recently, ISPs have moved beyond employing NATs only directly at individual customers and instead begun deploying Carrier-Grade NATs (CGNs) to apply address translation to many independent and disparate endpoints spanning physical locations, a phenomenon that so far has received little in the way of empirical assessment. In this work we present a broad and systematic study of the deployment and behavior of these middleboxes. We develop a methodology to detect the existence of hosts behind CGNs by extracting non-routable IP addresses from peer lists we obtain by crawling the BitTorrent DHT. We complement this approach with improvements to our Netalyzr troubleshooting service, enabling us to determine a range of indicators of CGN presence as well as detailed insights into key properties of CGNs. Combining the two data sources we illustrate the scope of CGN deployment on today's Internet, and report on characteristics of commonly deployed CGNs and their effect on end users

Computing the entropy of user navigation in the web

Navigation through the web, colloquially known as "surfing", is one of the main activities of users during web interaction. When users follow a navigation trail they often tend to get disoriented in terms of the goals of their original query and thus the discovery of typical user trails could be useful in providing navigation assistance. Herein, we give a theoretical underpinning of user navigation in terms of the entropy of an underlying Markov chain modelling the web topology. We present a novel method for online incremental computation of the entropy and a large deviation result regarding the length of a trail to realize the said entropy. We provide an error analysis for our estimation of the entropy in terms of the divergence between the empirical and actual probabilities. We then indicate applications of our algorithm in the area of web data mining. Finally, we present an extension of our technique to higher-order Markov chains by a suitable reduction of a higher-order Markov chain model to a first-order one

Plato on Well-Being

Plato's dialogues use several terms for the concept of well-being, which concept plays a central ethical role as the ultimate goal for action and a central political role as the proper aim for states. But the dialogues also reveal sharp debate about what human well-being is. I argue that they endorse a Socratic conception of well-being as virtuous activity, by considering and rejecting several alternatives, including an ordinary conception that lists a variety of goods, a Protagorean conception that identifies one's well-being with what appears one to be one's well-being, and hedonistic conceptions