Optical multiple access techniques for on-board routing

The purpose of this research contract was to design and analyze an optical multiple access system, based on Code Division Multiple Access (CDMA) techniques, for on board routing applications on a future communication satellite. The optical multiple access system was to effect the functions of a circuit switch under the control of an autonomous network controller and to serve eight (8) concurrent users at a point to point (port to port) data rate of 180 Mb/s. (At the start of this program, the bit error rate requirement (BER) was undefined, so it was treated as a design variable during the contract effort.) CDMA was selected over other multiple access techniques because it lends itself to bursty, asynchronous, concurrent communication and potentially can be implemented with off the shelf, reliable optical transceivers compatible with long term unattended operations. Temporal, temporal/spatial hybrids and single pulse per row (SPR, sometimes termed 'sonar matrices') matrix types of CDMA designs were considered. The design, analysis, and trade offs required by the statement of work selected a temporal/spatial CDMA scheme which has SPR properties as the preferred solution. This selected design can be implemented for feasibility demonstration with off the shelf components (which are identified in the bill of materials of the contract Final Report). The photonic network architecture of the selected design is based on M(8,4,4) matrix codes. The network requires eight multimode laser transmitters with laser pulses of 0.93 ns operating at 180 Mb/s and 9-13 dBm peak power, and 8 PIN diode receivers with sensitivity of -27 dBm for the 0.93 ns pulses. The wavelength is not critical, but 830 nm technology readily meets the requirements. The passive optical components of the photonic network are all multimode and off the shelf. Bit error rate (BER) computations, based on both electronic noise and intercode crosstalk, predict a raw BER of (10 exp -3) when all eight users are communicating concurrently. If better BER performance is required, then error correction codes (ECC) using near term electronic technology can be used. For example, the M(8,4,4) optical code together with Reed-Solomon (54,38,8) encoding provides a BER of better than (10 exp -11). The optical transceiver must then operate at 256 Mb/s with pulses of 0.65 ns because the 'bits' are now channel symbols

Nietzsche's Antisociology: Subjectified Culture and the End of History

This is the published version. Copyright 1995 University of Chicago Press.Although a very important figure in interdisciplinary social theory, Nietzsche is absent from sociological theory, especially in the United States. Equating rationalization with cultural homogenization and liquidation of particularity, Nietzsche saw "decadence" where modern social theorists saw progress. He held that sociology drapes cultural domination, regimentation, and exhaustion with the appearance of legitimacy. This essay explores his views about the depletion of social resources stressed in modern theory. It elaborates his "antisociology" and then traces the impact of this framework on three divergent currents of social theory. Nietzsche is read against the backdrop of modern theory in order to explore his continuing challenge to this tradition and his relevance to sociology

The Normative Foundations of Emancipatory Theory: Evolutionary Versus Pragmatic Perspectives

This is the published version. Copyright 1989 University of Chicago Press.From the start, emancipatory theory has been plagued by contradictory and incompletely elaborated normative underpinnings that weaken its sociological and ethical credibility. Jurgen Habermas, the leading contemporary critical theorist, has attempted to address this problem in an extensive reconstruction of the theories of Marx and Weber that appropriates elements of American pragmatist thought. Yet he resorts to an evolutionary normative argument that undermines the sociological powers of the two classical theories and contradicts the pragmatists' historical approach to values. This essay explains the significance of Habermasian theory for the emancipatory tradition, analyzes certain problems of the theory, and argues that an expanded dialogue with American pragmatism would strengthen both its sociological and its normative dimensions. Though the explicit focus is on the emancipatory tradition, the essay raises broader critical questions about pseudohistorical, normative justification in general sociological theory

After Postmodernism: Reactionary Tribalism

This is the published version. Copyright 2000 University of Chicago Press.Revived Weimar‐era “radical conservatism” and fresh “New Right” and “paleoconservative” theories offer a radical cultural critique of global capitalism and liberal democracy. Expressing a broader retribalization and perceived failure of modernization, their defense of communal particularity attacks the multicultural nation‐state, liberal rights, and universal citizenship. This essay links reactionary tribalism to a recurrent 20th‐century theoretical tendency, the “total critique of modernity”—a fusion of oversimplified Nietzschean and Weberian ideas. Historically, total critique has promoted convergence between right and left, such as the current overlapping facets of “radical conservatism” and “strong‐program postmodernism.” Total critique counters the “historicist” method of “internal critique” and the “communication model” characteristic of reflexive social theory. The discussion uncovers the mediating role of social theory in the problematic relationship of science and partially disenchanted public spheres in plural, democratic cultures

The histone H3K4 demethylase JARID1A directly interacts with haematopoietic transcription factor GATA1 in erythroid cells through its second PHD domain

Chromatin remodelling and transcription factors play important roles in lineage commitment and development through control of gene expression. Activation of selected lineage-specific genes and repression of alternative lineage-affiliated genes results in tightly regulated cell differentiation transcriptional programmes. However, the complex functional and physical interplay between transcription factors and chromatin modifying enzymes remains elusive. Recent evidence has implicated histone demethylases in normal haematopoietic differentiation as well as in malignant haematopoiesis. Here we report an interaction between H3K4 demethylase JARID1A and the haematopoietic-specific master transcription proteins SCL and GATA1 in red blood cells. Specifically, we observe a direct physical contact between GATA1 and the second PHD domain of JARID1A. This interaction has potential implications for normal and malignant haematopoiesis

Bessel Functions in Mass Action. Modeling of Memories and Remembrances

Data from experimental observations of a class of neurological processes (Freeman K-sets) present functional distribution reproducing Bessel function behavior. We model such processes with couples of damped/amplified oscillators which provide time dependent representation of Bessel equation. The root loci of poles and zeros conform to solutions of K-sets. Some light is shed on the problem of filling the gap between the cellular level dynamics and the brain functional activity. Breakdown of time-reversal symmetry is related with the cortex thermodynamic features. This provides a possible mechanism to deduce lifetime of recorded memory.Comment: 16 pages, 9 figures, Physics Letters A, 2015 in pres

Localization and chiral symmetry in 2+1 flavor domain wall QCD

We present results for the dependence of the residual mass of domain wall fermions (DWF) on the size of the fifth dimension and its relation to the density and localization properties of low-lying eigenvectors of the corresponding hermitian Wilson Dirac operator relevant to simulations of 2+1 flavor domain wall QCD. Using the DBW2 and Iwasaki gauge actions, we generate ensembles of configurations with a $16^3\times 32$ space-time volume and an extent of 8 in the fifth dimension for the sea quarks. We demonstrate the existence of a regime where the degree of locality, the size of chiral symmetry breaking and the rate of topology change can be acceptable for inverse lattice spacings $a^{-1} \ge 1.6$ GeV.Comment: 59 Pages, 23 figures, 1 MPG linke

Moral Communities or a Market State: The Supreme Court’s Vision of the Police Power in the Age of Globalization

In essence, this Article attempts to explain the underlying logic of two intersecting lines of recent Supreme Court decisions. The first line of cases concerns the allocation of constitutional power between the Nation and the States (i.e., cases about federalism ); the other line concerns claims of individual right against exercises of purported State power (i.e., cases about individual rights ). The federalism cases deal, respectively, with the powers of the States against Congress in the regulation of domestic matters \u27 and as against the Executive (and, less often, Congress) in influencing foreign affairs. The individual rights cases deal with equal access to State-provided benefits that take account of race and with State regulation of private decisionmaking under the auspices of police power. Both lines of cases can be understood as efforts by the Supreme Court to adapt the American constitutional order to what it perceives as the necessities of globalization, and specifically to the successful transition from the constitutional order of the Nation State to that of the Market State

Impacts of sea-level rise-induced erosion on the Catalan coast

The final publication is available at Springer via http://dx.doi.org/10.1007/s10113-016-1052-xThe Catalan coast as most of the developed Mediterranean coastal zone is characterized by the coincidence of stresses and pressures on the natural system with a high exposure and low adaptive capacity. Due to this, climate change-induced effects will increase natural hazards and aggravate their associated impacts and, in consequence, it is necessary to assess their effects for proper long-term management. In this work, we assess the impact of sea-level rise (SLR)-induced shoreline retreat on the Catalan coast for three scenarios ranging from 0.53 to 1.75 m by the year 2100. Implications are analysed in terms of affectation of two main functions provided by beaches, i.e. recreation and protection. Obtained results show that CC will be a serious threat to analysed functions since the expected enhanced shoreline retreat will severely decrease the recreational carrying capacity and the capacity of protection in the near future under tested scenarios. The actual level of development along the coastal zone reduces the natural resilient capacity of beaches to SLR in such a way that the lack of accommodation space can be identified as a main factor for the estimated impacts.Peer ReviewedPostprint (author's final draft