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Ecosystem Services (ES) are the benefits that people obtain from ecosystems. They result from structures, processes and functions within ecosystems performed by natural features and organisms, and which society makes direct use of, consciously or unconsciously. The ES concept results in a general broadening of perspectives considering environmental effects of human activities, as well as their costs and benefits, in an integrated manner. This paper addresses the use and relevance of the Ecosystems Services concept for the Waterborne Transport Infrastructure (WTI) sector. Considering the potential multi-functionality of WTI, welldesigned projects can create economic, social and environmental benefits well beyond their intended waterborne transport objectives. When planning a project, the consideration of how project engineering aspects interact with biodiversity, fisheries, recreation and other sectors allows planners and other stakeholders to make well informed decisions about trade-offs and opportunities. The ES concept helps to make these trade-offs visible and integrate these considerations into different stages of the project cycle. Building on a range of case studies, we provide practical guidance on how ES concepts can be successfully applied at different stages of a WTI project, signposting further guidance on how the navigation sector can supportively, beneficially, and profitably use ES concepts to enhance and promote WTI projects.

2,4'-Dihydroxyacetophenone dioxygenase (EC 1.13.11.41) was purified to homogeneity from Alcaligenes sp. 4HAP grown on 4-hydroxyacetophenone. Measurements of the M(r) of the native enzyme ranged from 81600 to 87000, whereas values of 21000 and 20379 were given by SDS/PAGE and electrospray MS respectively. The enzyme is a homotetramer and contains one atom of iron per molecule of enzyme. From C- and N-terminal analyses, primers for PCR were designed and the dad gene cloned and sequenced. The predicted amino acid sequence of dad, deduced from the nucleotide sequence, confirms the N-terminal amino acid sequencing data and contains the sequence of an internal tryptic peptide. It gave a calculated M(r) of 20364. The gene was expressed in Escherichia coli and yielded active enzyme. The derived amino acid sequence does not show significant similarity to other dioxygenases or any strong similarity to protein sequences presently available in the databases.

Objective: This study evaluated whether the use of kinesio taping (KT) would enhance the effect of physical therapy in relieving pain, improving muscle endurance, and boosting functional capacity in adolescents with hemophilia who experience low back pain. Methods: Forty-five adolescents with hemophilia (age; 10-13 years) assigned randomly into three treatment arms; KT applied paraspinal alongside a physical exercise program conducted three times/week for three successive months (KT group; n=15), placebo taping plus physical exercise (Placebo group; n=15), or physical exercise only (Control group; n=15). Lower back pain, back muscle endurance, and functional capacity assessed pre- and post-treatment. Results: Lower back pain reduced significantly in the KT group as compared to the control group (P=.001), but not to the placebo group (P=.19). Back muscle endurance increased significantly in the KT group relative to either the placebo (P=.004) or the control group (P=.043). Additionally, functional capacity improved significantly in the KT group as compared to the control (P=.039) group but not to the placebo group (P=.58). Conclusion: KT is an effective adjunctive therapy to reduce lower back pain, improve back muscle endurance, and enhance functional capacity in adolescents with hemophilia., {"references":["Fijnvandraat K, Cnossen MH, Leebeek FW, Peters M. Diagnosis and management of haemophilia. BMJ (Clinical research ed) 2012;344:e2707","Knobe K, Berntorp E. Haemophilia and joint disease: pathophysiology, evaluation, and management. J Comorb 2011;1(1):51-9.","Lissauer T, Carroll W. Illustrated textbook of paediatrics: Elsevier Health Sciences; 2017","Tagariello G, Iorio A, Santagostino E, Morfini M, Bisson R, Innocenti M, et al. Comparison of the rates of joint arthroplasty in patients with severe factor VIII and IX deficiency: an index of different clinical severity of the 2 coagulation disorders. Blood 2009;114(4):779-84","Chen S-L. Economic costs of hemophilia and the impact of prophylactic treatment on patient management. Am J Manag Care 2016;22(5 Suppl):s126-33","Wallny T, Hess L, Seuser A, Zander D, Brackmann H, Kraft C. Pain status of patients with severe haemophilic arthropathy. Haemophilia 2001;7(5):453-8","Gallach J, Querol F, Gonzalez L, Pardo A, Aznar J. Posturographic analysis of balance control in patients with haemophilic arthropathy. Haemophilia 2008; 14(2):329-35.","Kankaanpää M, Taimela S, Laaksonen D, Hänninen O, Airaksinen O. Back and hip extensor fatigability in chronic low back pain patients and controls. Arch Phys Med Rehabil 1998;79(4):412-7","Moffroid MT. Endurance of trunk muscles in persons with chronic low back pain: assessment, performance, training. J Rehabil Res Dev 1997;34:440-7","Candotti CT, Loss JF, Pressi AMS, de Souza Castro FA, La Torre M, de Oliveira Melo M, et al. Electromyography for assessment of pain in low back muscles. Phys ther 2008;88(9):1061-7","Alschuler KN, Neblett R, Wiggert E, Haig AJ, Geisser ME. Flexion-relaxation and clinical features associated with chronic low back pain: a comparison of different methods of quantifying flexion-relaxation. Clin J Pain 2009;25(9):760-6","Srivastava A, Brewer A, Mauser-Bunschoten E, Key NS, Kitchen S, Llinas A, et al. Guidelines for the management of hemophilia. Haemophilia 2013;19(1):1-47","Kaya E, Zinnuroglu M, Tugcu I. Kinesio taping compared to physical therapy modalities for the treatment of shoulder impingement syndrome. Clin Rheumatol 2011; 30(2):201-7","Hopper D. Successful use of Kinesio tape to treat an acute muscle haematoma. J Haem Pract 2015; 2(1):12-5","Williams S, Whatman C, Hume PA, Sheerin K. Kinesio taping in treatment and prevention of sports injuries. Sports Med. 2012;42(2):153-64"]}

Abrasive wear of the orifice cannot be avoided for a hopper which should be operated uninterruptedly for a long time in engineering applications. Consequently, the change of the orifice shape will lead to the variation of flow rate for the hopper. In this paper, the influence of orifice shape on the flow rate in ordinary flat-bottom hoppers is investigated both numerically and experimentally. The flow rate increases when the orifice is from sharp to smooth in both flat-bottom and conical-bottom hoppers. The data can be well fitted with a modified Beverloo's formula. The result is supported by the profile of kinetic pressure near the orifice. Moreover, the fluctuation of the instantaneous flow rate is reduced with smooth orifice. In addition, it is found that the diameter of the hopper D and the thickness of the bottom H do not influence the flow rate. This paper contributes to control the flow rate by optimizing the shape of orifice.

Bacterial quorum-sensing systems coordinate cellular behaviors—such as virulence and biofilm formation—across a population and are based on the release of small molecules that, when present in sufficient abundance, flip gene expression switches. HQNO (2-n-heptyl-4-hydroxyquinoline-N-oxide), which inhibits bacterial respiration by inhibiting the cytochrome bc 1 complex (also called complex III), is a quorum factor secreted by Pseudomonas aeruginosa that inhibits the growth of competing bacteria. Although wild-type planktonic P . aeruginosa undergo spontaneous autolysis when cultured for more than 48 hours, Hazan et al . found that P . aeruginosa mutants that were incapable of synthesizing HQNO and several related compounds did not undergo autolysis. Adding physiologically relevant concentrations of HQNO to the culture medium restored autolysis in a dose-dependent manner. The ability of HQNO to induce autolysis required the quinol-binding site and the electron-acceptor site of the cytochrome bc 1 complex. Inhibition of the cytochrome bc 1 complex induces a burst of reactive oxygen species (ROS). Cultures undergoing autolysis exhibited a ROS burst, and the addition of ROS scavengers to the culture medium inhibited autolysis. In eukaryotes, inhibition of the cytochrome bc 1 complex disrupts the mitochondrial membrane and membrane potential. Experiments with a membrane-impermeable dye and a fluorescent indicator of membrane potential indicated that HQNO treatment increased membrane permeability and reduced membrane potential in P. aeruginosa . Experiments with P. aeruginosa using compounds that target the cytochrome bc 1 complex in mitochondria suggested that membrane permeabilization and depolarization in bacterial autolysis occur through a mechanism similar to that of eukaryotic cells undergoing apoptosis (see Zemke and Bomberger). DNA is a major component of the biofilm matrix, a structure that protects microbes from antibiotics. Exogenously supplied HQNO partially rescued biofilm formation in quorum-sensing mutants and promoted tolerance to the antibiotic meropenem. The addition of DNAse to the culture medium impaired HQNO-enhanced biofilm formation and antibiotic tolerance, suggesting that autolysis was important for releasing DNA that could be used in forming the matrix. These results demonstrate that in addition to releasing spores and eliminating phage-infected cells, bacterial autolysis can benefit the population by promoting the formation of biofilms. R. Hazan, Y. A. Que, D. Maura, B. Strobel, P. A. Majcherczyk, L. R. Hopper, D. J. Wilbur, T. N. Hreha, B. Barquera, L. G. Rahme, Auto poisoning of the respiratory chain by a quorum-sensing-regulated molecule favors biofilm formation and antibiotic tolerance. Curr. Biol . 26 , 195–206 (2016). [PubMed] A. C. Zemke, J. M. Bomberger, Microbiology: Social suicide for a good cause. Curr. Biol . 26 , R80–R82 (2016). [PubMed]

The jamming phenomenon of granular flow of mono-disperse disks in a two-dimensional hopper is studied experimentally. When the opening of the hopper d is small, jamming occurs due to formation of an arch at the hopper opening. The jamming probability as a function of the hopper opening width is measured which show a sharp decrease at some range of d . By observing the disk configurations of the arch in the jamming events, the jamming probability can be explained quantitatively using a restricted random walker model. The average horizontal and vertical spans of the jamming arch are calculated from the restricted random walk model which compares favorably with experiments.

Poster: "ECR 2013 / C-1546 / The development and reliability of a new CT grading system for hip osteoarthritis" by: "T. Turmezei, M. A. Hopper, D. J. Lomas, K. E. S. Poole; Cambridge/UK"

Since the first days of the World Wide Web, artists like myself have been exploring the new possibilities of network interactivity. Some good tools and languages have been developed and made available free for the public to use. This has empowered individuals to participate in the media in ways that are quite remarkable. Nonetheless, the future of independent media is clouded by legal, regulatory, and organisational challenges that need to be addressed. It is not clear to what extent independent content producers will be able to build upon the successes of the 90s – it is yet to be seen whether their efforts will be largely nullified by the anticyclones of a hostile media market. Not so long ago, American news magazines were covering the Browser War. Several real wars later, the terms of surrender are becoming clearer. Now both of the major Internet browsers are owned by huge media corporations, and most of the states (and Reagan-appointed judges) that were demanding the break-up of Microsoft have given up. A curious about-face occurred in U.S. Justice Department policy when John Ashcroft decided to drop the federal case. Maybe Microsoft's value as a partner in covert activity appealed to Ashcroft more than free competition. Regardless, Microsoft is now turning its wrath on new competitors, people who are doing something very, very bad: sharing the products of their own labour. This practice of sharing source code and building free software infrastructure is epitomised by the continuing development of Linux. Everything in the Linux kernel is free, publicly accessible information. As a rule, the people building this "open source" operating system software believe that maintaining transparency is important. But U.S. courts are not doing much to help. In a case brought by the Motion Picture Association of America against Eric Corley, a federal district court blocked the distribution of source code that enables these systems to play DVDs. In addition to censoring Corley's journal, the court ruled that any programmer who writes a program that plays a DVD must comply with a host of license restrictions. In short, an established and popular media format (the DVD) cannot be used under open source operating systems without sacrificing the principle that software source code should remain in the public domain. Should the contents of operating systems be tightly guarded secrets, or subject to public review? If there are capable programmers willing to create good, free operating systems, should the law stand in their way? The question concerning what type of software infrastructure will dominate personal computers in the future is being answered as much by disappointing legal decisions as it is by consumer choice. Rather than ensuring the necessary conditions for innovation and cooperation, the courts permit a monopoly to continue. Rather than endorsing transparency, secrecy prevails. Rather than aiming to preserve a balance between the commercial economy and the gift-economy, sharing is being undermined by the law. Part of the mystery of the Internet for a lot of newcomers must be that it seems to disprove the old adage that you can't get something for nothing. Free games, free music, free pornography, free art. Media corporations are doing their best to change this situation. The FBI and trade groups have blitzed the American news media with alarmist reports about how children don't understand that sharing digital information is a crime. Teacher Gail Chmura, the star of one such media campaign, says of her students, "It's always been interesting that they don't see a connection between the two. They just don't get it" (Hopper). Perhaps the confusion arises because the kids do understand that digital duplication lets two people have the same thing. Theft is at best a metaphor for the copying of data, because the original is not stolen in the same sense as a material object. In the effort to liken all copying to theft, legal provisions for the fair use of intellectual property are neglected. Teachers could just as easily emphasise the importance of sharing and the development of an electronic commons that is free for all to use. The values advanced by the trade groups are not beyond question and are not historical constants. According to Donald Krueckeberg, Rutgers University Professor of Urban Planning, native Americans tied the concept of property not to ownership but to use. "One used it, one moved on, and use was shared with others" (qtd. in Batt). Perhaps it is necessary for individuals to have dominion over some private data. But who owns the land, wind, sun, and sky of the Internet – the infrastructure? Given that publicly-funded research and free software have been as important to the development of the Internet as have business and commercial software, it is not surprising that some ambiguity remains about the property status of the dataverse. For many the Internet is as much a medium for expression and the interplay of languages as it is a framework for monetary transaction. In the case involving DVD software mentioned previously, there emerged a grass-roots campaign in opposition to censorship. Dozens of philosophical programmers and computer scientists asserted the expressive and linguistic bases of software by creating variations on the algorithm needed to play DVDs. The forbidden lines of symbols were printed on T-shirts, translated into different computer languages, translated into legal rhetoric, and even embedded into DNA and pictures of MPAA president Jack Valenti (see e.g. Touretzky). These efforts were inspired by a shared conviction that important liberties were at stake. Supporting the MPAA's position would do more than protect movies from piracy. The use of the algorithm was not clearly linked to an intent to pirate movies. Many felt that outlawing the DVD algorithm, which had been experimentally developed by a Norwegian teenager, represented a suppression of gumption and ingenuity. The court's decision rejected established principles of fair use, denied the established legality of reverse engineering software to achieve compatibility, and asserted that journalists and scientists had no right to publish a bit of code if it might be misused. In a similar case in April 2000, a U.S. court of appeals found that First Amendment protections did apply to software (Junger). Noting that source code has both an expressive feature and a functional feature, this court held that First Amendment protection is not reserved only for purely expressive communication. Yet in the DVD case, the court opposed this view and enforced the inflexible demands of the Digital Millennium Copyright Act. Notwithstanding Ted Nelson's characterisation of computers as literary machines, the decision meant that the linguistic and expressive aspects of software would be subordinated to other concerns. A simple series of symbols were thereby cast under a veil of legal secrecy. Although they were easy to discover, and capable of being committed to memory or translated to other languages, fair use and other intuitive freedoms were deemed expendable. These sorts of legal obstacles are serious challenges to the continued viability of free software like Linux. The central value proposition of Linux-based operating systems – free, open source code – is threatening to commercial competitors. Some corporations are intent on stifling further development of free alternatives. Patents offer another vulnerability. The writing of free software has become a minefield of potential patent lawsuits. Corporations have repeatedly chosen to pursue patent litigation years after the alleged infringements have been incorporated into widely used free software. For example, although it was designed to avoid patent problems by an array of international experts, the image file format known as JPEG (Joint Photographic Experts Group) has recently been dogged by patent infringement charges. Despite good intentions, low-budget initiatives and ad hoc organisations are ill equipped to fight profiteering patent lawsuits. One wonders whether software innovation is directed more by lawyers or computer scientists. The present copyright and patent regimes may serve the needs of the larger corporations, but it is doubtful that they are the best means of fostering software innovation and quality. Orwell wrote in his Homage to Catalonia, There was a new rule that censored portions of the newspaper must not be left blank but filled up with other matter; as a result it was often impossible to tell when something had been cut out. The development of the Internet has a similar character: new diversions spring up to replace what might have been so that the lost potential is hardly felt. The process of retrofitting Internet software to suit ideological and commercial agendas is already well underway. For example, Microsoft has announced recently that it will discontinue support for the Java language in 2004. The problem with Java, from Microsoft's perspective, is that it provides portable programming tools that work under all operating systems, not just Windows. With Java, programmers can develop software for the large number of Windows users, while simultaneously offering software to users of other operating systems. Java is an important piece of the software infrastructure for Internet content developers. Yet, in the interest of coercing people to use only their operating systems, Microsoft is willing to undermine thousands of existing Java-language projects. Their marketing hype calls this progress. The software industry relies on sales to survive, so if it means laying waste to good products and millions of hours of work in order to sell something new, well, that's business. The consequent infrastructure instability keeps software developers, and other creative people, on a treadmill. From Progressive Load by Andy Deck, artcontext.org/progload As an Internet content producer, one does not appeal directly to the hearts and minds of the public; one appeals through the medium of software and hardware. Since most people are understandably reluctant to modify the software running on their computers, the software installed initially is a critical determinant of what is possible. Unconventional, independent, and artistic uses of the Internet are diminished when the media infrastructure is effectively established by decree. Unaccountable corporate control over infrastructure software tilts the playing field against smaller content producers who have neither the advance warning of industrial machinations, nor the employees and resources necessary to keep up with a regime of strategic, cyclical obsolescence. It seems that independent content producers must conform to the distribution technologies and content formats favoured by the entertainment and marketing sectors, or else resign themselves to occupying the margins of media activity. It is no secret that highly diversified media corporations can leverage their assets to favour their own media offerings and confound their competitors. Yet when media giants AOL and Time-Warner announced their plans to merge in 2000, the claim of CEOs Steve Case and Gerald Levin that the merged companies would "operate in the public interest" was hardly challenged by American journalists. Time-Warner has since fought to end all ownership limits in the cable industry; and Case, who formerly championed third-party access to cable broadband markets, changed his tune abruptly after the merger. Now that Case has been ousted, it is unclear whether he still favours oligopoly. According to Levin, global media will be and is fast becoming the predominant business of the 21st century ... more important than government. It's more important than educational institutions and non-profits. We're going to need to have these corporations redefined as instruments of public service, and that may be a more efficient way to deal with society's problems than bureaucratic governments. Corporate dominance is going to be forced anyhow because when you have a system that is instantly available everywhere in the world immediately, then the old-fashioned regulatory system has to give way (Levin). It doesn't require a lot of insight to understand that this "redefinition," this slight of hand, does not protect the public from abuses of power: the dissolution of the "old-fashioned regulatory system" does not serve the public interest. From Lexicon by Andy Deck, artcontext.org/lexicon) As an artist who has adopted telecommunications networks and software as his medium, it disappoints me that a mercenary vision of electronic media's future seems to be the prevailing blueprint. The giantism of media corporations, and the ongoing deregulation of media consolidation (Ahrens), underscore the critical need for independent media sources. If it were just a matter of which cola to drink, it would not be of much concern, but media corporations control content. In this hyper-mediated age, content – whether produced by artists or journalists – crucially affects what people think about and how they understand the world. Content is not impervious to the software, protocols, and chicanery that surround its delivery. It is about time that people interested in independent voices stop believing that laissez faire capitalism is building a better media infrastructure. The German writer Hans Magnus Enzensberger reminds us that the media tyrannies that affect us are social products. The media industry relies on thousands of people to make the compromises necessary to maintain its course. The rapid development of the mind industry, its rise to a key position in modern society, has profoundly changed the role of the intellectual. He finds himself confronted with new threats and new opportunities. Whether he knows it or not, whether he likes it or not, he has become the accomplice of a huge industrial complex which depends for its survival on him, as he depends on it for his own. He must try, at any cost, to use it for his own purposes, which are incompatible with the purposes of the mind machine. What it upholds he must subvert. He may play it crooked or straight, he may win or lose the game; but he would do well to remember that there is more at stake than his own fortune (Enzensberger 18). Some cultural leaders have recognised the important role that free software already plays in the infrastructure of the Internet. Among intellectuals there is undoubtedly a genuine concern about the emerging contours of corporate, global media. But more effective solidarity is needed. Interest in open source has tended to remain superficial, leading to trendy, cosmetic, and symbolic uses of terms like "open source" rather than to a deeper commitment to an open, public information infrastructure. Too much attention is focussed on what's "cool" and not enough on the road ahead. Various media specialists – designers, programmers, artists, and technical directors – make important decisions that affect the continuing development of electronic media. Many developers have failed to recognise (or care) that their decisions regarding media formats can have long reaching consequences. Web sites that use media formats which are unworkable for open source operating systems should be actively discouraged. Comparable technologies are usually available to solve compatibility problems. Going with the market flow is not really giving people what they want: it often opposes the work of thousands of activists who are trying to develop open source alternatives (see e.g. Greene). Average Internet users can contribute to a more innovative, free, open, and independent media – and being conscientious is not always difficult or unpleasant. One project worthy of support is the Internet browser Mozilla. Currently, many content developers create their Websites so that they will look good only in Microsoft's Internet Explorer. While somewhat understandable given the market dominance of Internet Explorer, this disregard for interoperability undercuts attempts to popularise standards-compliant alternatives. Mozilla, written by a loose-knit group of activists and programmers (some of whom are paid by AOL/Time-Warner), can be used as an alternative to Microsoft's browser. If more people use Mozilla, it will be harder for content providers to ignore the way their Web pages appear in standards-compliant browsers. The Mozilla browser, which is an open source initiative, can be downloaded from http://www.mozilla.org/. While there are many people working to create real and lasting alternatives to the monopolistic and technocratic dynamics that are emerging, it takes a great deal of cooperation to resist the media titans, the FCC, and the courts. Oddly enough, corporate interests sometimes overlap with those of the public. Some industrial players, such as IBM, now support open source software. For them it is mostly a business decision. Frustrated by the coercive control of Microsoft, they support efforts to develop another operating system platform. For others, including this writer, the open source movement is interesting for the potential it holds to foster a more heterogeneous and less authoritarian communications infrastructure. Many people can find common cause in this resistance to globalised uniformity and consolidated media ownership. The biggest challenge may be to get people to believe that their choices really matter, that by endorsing certain products and operating systems and not others, they can actually make a difference. But it's unlikely that this idea will flourish if artists and intellectuals don't view their own actions as consequential. There is a troubling tendency for people to see themselves as powerless in the face of the market. This paralysing habit of mind must be abandoned before the media will be free. Works Cited Ahrens, Frank. "Policy Watch." Washington Post (23 June 2002): H03. 30 March 2003 . Batt, William. "How Our Towns Got That Way." 7 Oct. 1996. 31 March 2003 . Chester, Jeff. "Gerald Levin's Negative Legacy." Alternet.org 6 Dec. 2001. 5 March 2003 . Enzensberger, Hans Magnus. "The Industrialisation of the Mind." Raids and Reconstructions. London: Pluto Press, 1975. 18. Greene, Thomas C. "MS to Eradicate GPL, Hence Linux." 25 June 2002. 5 March 2003 . Hopper, D. Ian. "FBI Pushes for Cyber Ethics Education." Associated Press 10 Oct. 2000. 29 March 2003 . Junger v. Daley. U.S. Court of Appeals for 6th Circuit. 00a0117p.06. 2000. 31 March 2003 . Levin, Gerald. "Millennium 2000 Special." CNN 2 Jan. 2000. Touretzky, D. S. "Gallery of CSS Descramblers." 2000. 29 March 2003 . Links http://artcontext.org/lexicon/ http://artcontext.org/progload http://pacer.ca6.uscourts.gov/cgi-bin/getopn.pl?OPINION=00a0117p.06 http://www.billingsgazette.com/computing/20001010_cethics.html http://www.cs.cmu.edu/~dst/DeCSS/Gallery http://www.democraticmedia.org/resources/editorials/levin.html http://www.esb.utexas.edu/drnrm/WhatIs/LandValue.htm http://www.mozilla.org/ http://www.theregus.com/content/4/25378.html http://www.washingtonpost.com/ac2/wp-dyn/A27015-2002Jun22?language=printer Citation reference for this article Substitute your date of access for Dn Month Year etc... MLA Style Deck, Andy. "Treadmill Culture " M/C: A Journal of Media and Culture< http://www.media-culture.org.au/0304/04-treadmillculture.php>. APA Style Deck, A. (2003, Apr 23). Treadmill Culture . M/C: A Journal of Media and Culture, 6,< http://www.media-culture.org.au/0304/04-treadmillculture.php>

We perform granular flow experiments using metal disks falling through a two-dimensional hopper. When the opening of the hopper d is small, jamming occurs due to formation of an arch at the hopper opening. We study the statistical properties of the horizontal component X and the vertical component Y of the arch vector that is defined as the displacement vector from the center of the first disk to the center of the last disk in the arch. As d increases, the distribution function of X changes from a steplike function to a smooth function while that of Y remains symmetrical and peaked at Y=0. When the arch vectors are classified according to the number of disk n in the arch, the mean valuenis found to increase with d. In addition, the horizontal component X(n) and the absolute value of the vertical component /Y(n)/ in each class have mean values increasing with n. Regarding the arch as a trajectory of a restricted random walker, we derive an expression for the probability density function a(n)(X) of forming an n-disk arch. The statistics (n,X(n),/Y(n)/and the fraction g(d)(n) of n-disk arches) of the arches generated by a(n)(X) agree with those found in the experiment.

The flavocytochrome p-cresol methylhydroxylase from Pseudomonas putida has been reported to have a Mr of 114,000 and to consist of two subunits, a flavoprotein and a cytochrome c, each with a Mr of 58,000. Recent X-ray crystallographic data from our laboratories [Shamala, N., Lim, L. W., Mathews, F. S., McIntire, W., Singer, T. P., & Hopper, D. J. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 4626-4630], however, indicate an alpha 2 beta 2 structure and a much lower molecular mass (approximately 8000) for the cytochrome subunit. In this paper we report data confirming the conclusions of X-ray crystallographic analysis. From quantitative amino acid analysis, the molecular mass of the flavoprotein monomer is shown to be 48,600 +/- 2200 and that of the cytochrome 8780 +/- 250. These values have been confirmed by gel electrophoresis under denaturing conditions. Gel chromatography under nondenaturing conditions shows that the isolated flavoprotein exists as a dimer, whereas the isolated cytochrome is a monomer. The complete amino acid sequence of the cytochrome c subunit is presented and is shown to have regions of homology to other bacterial c-type cytochromes. The partial N-terminal amino acid sequence (56 amino acids) of the flavoprotein subunit is also reported. The implications of the now established tetrameric structure of the flavocytochrome on data in the literature regarding the redox and association properties of the subunits are examined.