Showing papers by "University of California, San Diego published in 1996"
TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.
12,798 citations
TL;DR: In this paper, the sensitivity and kinetics of TNF-α-induced apoptosis were shown to be enhanced in a number of cell types expressing a dominant negative IkappaBalpha (Ikappa-BalphaM).
Abstract: Tumor necrosis factor alpha (TNF-alpha) signaling gives rise to a number of events, including activation of transcription factor NF-kappaB and programmed cell death (apoptosis). Previous studies of TNF-alpha signaling have suggested that these two events occur independently. The sensitivity and kinetics of TNF-alpha-induced apoptosis are shown to be enhanced in a number of cell types expressing a dominant-negative IkappaBalpha (IkappaBalphaM). These findings suggest that a negative feedback mechanism results from TNF-alpha signaling in which NF-kappaB activation suppresses the signals for cell death.
2,515 citations
TL;DR: The green fluorescent protein (GFP) from the Pacific Northwest jellyfish Aequorea victoria has generated intense interest as a marker for gene expression and localization of gene products.
Abstract: The green fluorescent protein (GFP) from the Pacific Northwest jellyfish Aequorea victoria has generated intense interest as a marker for gene expression and localization of gene products. The chromophore, resulting from the spontaneous cyclization and oxidation of the sequence -Ser65 (or Thr65)-Tyr66-Gly67-, requires the native protein fold for both formation and fluorescence emission. The structure of Thr65 GFP has been determined at 1.9 angstrom resolution. The protein fold consists of an 11-stranded beta barrel with a coaxial helix, with the chromophore forming from the central helix. Directed mutagenesis of one residue adjacent to the chromophore, Thr203, to Tyr or His results in significantly red-shifted excitation and emission maxima.
2,232 citations
TL;DR: It is suggested that CBP/p300 serves as an integrator of multiple signal transduction pathways within the nucleus, in addition to distinct coactivators for function of nuclear receptors, CREB, and AP-1.
2,184 citations
Book•
15 Oct 1996TL;DR: A new framework in which interactions, occurring at all levels, give rise to emergent forms and behaviors that are not themselves directly contained in the genes in any domain-specific way is described.
Abstract: Rethinking Innateness asks the question, "What does it really mean to say that a behavior is innate?" The authors describe a new framework in which interactions, occurring at all levels, give rise to emergent forms and behaviors. These outcomes often may be highly constrained and universal, yet are not themselves directly contained in the genes in any domain-specific way. One of the key contributions of Rethinking Innateness is a taxonomy of ways in which a behavior can be innate. These include constraints at the level of representation, architecture, and timing; typically, behaviors arise through the interaction of constraints at several of these levels.The ideas are explored through dynamic models inspired by a new kind of "developmental connectionism," a marriage of connectionist models and developmental neurobiology, forming a new theoretical framework for the study of behavioral development. While relying heavily on the conceptual and computational tools provided by connectionism, Rethinking Innateness also identifies ways in which these tools need to be enriched by closer attention to biology.
2,031 citations
TL;DR: This work investigated how TNFR1 activates different effector functions; the protein kinase JNK, transcription factor NF-kappaB, and apoptosis, finding that the three responses are mediated through separate pathways.
1,988 citations
TL;DR: In this article, the authors describe the various physical processes relating near-surface atmospheric and oceanographic bulk variables ; their relationship to the surface fluxes of momentum, sensible heat, and latent heat ; and their expression in a bulk flux algorithm.
Abstract: This paper describes the various physical processes relating near-surface atmospheric and oceanographic bulk variables ; their relationship to the surface fluxes of momentum, sensible heat, and latent heat ; and their expression in a bulk flux algorithm. The algorithm follows the standard Monin-Obukhov similarity approach for near-surface meteorological measurements but includes separate models for the ocean's cool skin and the diurnal warm layer, which are used to derive true skin temperature from the bulk temperature measured at some depth near the surface. The basic structure is an outgrowth of the Liu-Katsaros-Businger [Liu et al., 1979] method, with modifications to include a different specification of the roughness/stress relationship, a gustiness velocity to account for the additional flux induced by boundary layer scale variability, and profile functions obeying the convective limit. Additionally, we have considered the contributions of the sensible heat carried by precipitation and the requirement that the net dry mass flux be zero (the so-called Webb correction [Webb et al., 1980]). The algorithm has been tuned to fit measurements made on the R/V Moana Wave in the three different cruise legs made during the Coupled Ocean-Atmosphere Response Experiment. These measurements yielded 1622 fifty-min averages of fluxes and bulk variables in the wind speed range from 0.5 to 10 m s -1 . The analysis gives statistically reliable values for the Charnock [1955] constant (a = 0.011) and the gustiness parameter (β = 1.25). An overall mean value for the latent heat flux, neutral bulk-transfer coefficient was 1.11 x 10 -3 , declining slightly with increasing wind speed. Mean values for the sensible and latent heat fluxes were 9.1 and 103.5 W m -2 ; mean values for the Webb and rain heat fluxes were 2.5 and 4.5 W m -2 . Accounting for all factors, the net surface heat transfer to the ocean was 17.9 ± 10 W m -2 .
1,924 citations
18 Aug 1996
TL;DR: Two new, simple, and practical constructions of message authentication schemes based on a cryptographic hash function, NMAC and HMAC, are proven to be secure as long as the underlying hash function has some reasonable cryptographic strengths.
Abstract: The use of cryptographic hash functions like MD5 or SHA-1 for message authentication has become a standard approach in many applications, particularly Internet security protocols. Though very easy to implement, these mechanisms are usually based on ad hoc techniques that lack a sound security analysis.
We present new, simple, and practical constructions of message authentication schemes based on a cryptographic hash function. Our schemes, NMAC and HMAC, are proven to be secure as long as the underlying hash function has some reasonable cryptographic strengths. Moreover we show, in a quantitative way, that the schemes retain almost all the security of the underlying hash function. The performance of our schemes is essentially that of the underlying hash function. Moreover they use the hash function (or its compression function) as a black box, so that widely available library code or hardwair can be used to implement them in a simple way, and replaceability of the underlying hash function is easily supported.
1,815 citations
TL;DR: Many of the quarterly oil price increases observed since 1985 are corrections to even bigger oil price decreases the previous quarter as mentioned in this paper, and when one looks at the net increase in oil prices over the year, recent data are consistent with the historical correlation between oil shocks and recessions.
1,772 citations
TL;DR: This double dissociation shows that the limbic-diencephalic regions damaged in amnesia and the neostriatum damaged in Parkinson's disease support separate and parallel learning systems.
Abstract: Amnesic patients and nondemented patients with Parkinson's disease were given a probabilistic classification task in which they learned which of two outcomes would occur on each trial, given the particular combination of cues that appeared. Amnesic patients exhibited normal learning of the task but had severely impaired declarative memory for the training episode. In contrast, patients with Parkinson's disease failed to learn the probabilistic classification task, despite having intact memory for the training episode. This double dissociation shows that the limbic-diencephalic regions damaged in amnesia and the neostriatum damaged in Parkinson's disease support separate and parallel learning systems. In humans, the neostriatum (caudate nucleus and putamen) is essential for the gradual, incremental learning of associations that is characteristic of habit learning. The neostriatum is important not just for motor behavior and motor learning but also for acquiring nonmotor dispositions and tendencies that depend on new associations.
1,672 citations
TL;DR: The results demonstrate that the production of more and better GFP variants is possible and worthwhile, and facilitates multicolor imaging of differential gene expression, protein localization or cell fate.
Posted Content•
TL;DR: This paper found that outsourcing can account for 31-51% of the increase in the relative demand for skilled labor that occurred in US manufacturing industries during the 1980s, compared to their previous estimate of 15-33% by using data from the revised NBER trade database.
Abstract: There is considerable debate over whether international trade has contributed to the declining economic fortunes of less skilled workers One issue that has become lost in the current discussion is how firms respond to import competition and how these responses, in turn, are transmitted to the labor market In previous work, we have argued that outsourcing, by which we mean the import of intermediate inputs by domestic firms, has contributed to an increase in the relative demand for skilled labor in the United States If firms respond to import competition from low-wage countries by moving non- skill-intensive activities abroad, then trade will shift employment towards skilled workers within industries In this paper, we extend our previous work by combining new import data from the revised NBER trade database with disaggregated data on input purchases from the Census of Manufactures We construct industry-by-industry estimates of outsourcing for the period 1972-1990 and reexamine whether outsourcing has contributed to an increase in relative demand for skilled labor Our main finding is that outsourcing can account for 31-51% of the increase in the relative demand for skilled labor that occurred in US manufacturing industries during the 1980s, compared to our previous estimate of 15-33%
TL;DR: In this paper, a model of the magnetization within these particles consisting of ferrimagnetically aligned core spins and a spin-glass-like surface layer is proposed, and the qualitative features of this model are reproduced by a numerical calculation of the spin distribution.
Abstract: Nickel ferrite nanoparticles exhibit anomalous magnetic properties at low temperatures: low magnetization with a large differential susceptibility at high fields, hysteresis loops which are open up to 160 kOe, time-dependent magnetization in 70 kOe applied field, and shifted hysteresis loops after field cooling. We propose a model of the magnetization within these particles consisting of ferrimagnetically aligned core spins and a spin-glass-like surface layer. We find that qualitative features of this model are reproduced by a numerical calculation of the spin distribution. Implications of this model for possible macroscopic quantum tunneling in these materials are discussed.
TL;DR: The data indicate that En-1 is required for delineating the ventral AER boundary and for restricting expression of signalling molecules, such as Fgf-8 and Bmp-2, to the distalmost ectoderm, a function reminiscent of engrailed's role in compartment border formation in D r o s ~ p h i l a ~~ ~ ~ .
Abstract: Neocortical neurons display a wide range of dendritic morphologies, ranging from compact arborizations to highly elaborate branching patterns. In vitro electrical recordings from these neurons have revealed a correspondingly diverse range of intrinsic firing patterns, including non-adapting, adapting and bursting types. This heterogeneity of electrical responsivity has generally been attributed to variability in the types and densities of ionic channels. We show here, using compartmental models of reconstructed cortical neurons, that an entire spectrum of firing patterns can be reproduced in a set of neurons that share a common distribution of ion channels and differ only in their dendritic geometry. The essential behaviour of the model depends on partial electrical coupling of fast active conductances localized to the soma and axon and slow active currents located throughout the dendrites, and can be reproduced in a two-compartment model. The results suggest a causal relationship for the observed correlations between dendritic structure and firing properties and emphasize the importance of active dendritic conductances in neuronal function.
TL;DR: Although ISS are necessary for gene vaccination, they down-regulate gene expression and thus may interfere with gene replacement therapy by inducing proinflammatory cytokines.
Abstract: Vaccination with naked DNA elicits cellular and humoral immune responses that have a T helper cell type 1 bias. However, plasmid vectors expressing large amounts of gene product do not necessarily induce immune responses to the encoded antigens. Instead, the immunogenicity of plasmid DNA (pDNA) requires short immunostimulatory DNA sequences (ISS) that contain a CpG dinucleotide in a particular base context. Human monocytes transfected with pDNA or double-stranded oligonucleotides containing the ISS, but not those transfected with ISS-deficient pDNA or oligonucleotides, transcribed large amounts of interferon-α, interferon-β, and interleukin-12. Although ISS are necessary for gene vaccination, they down-regulate gene expression and thus may interfere with gene replacement therapy by inducing proinflammatory cytokines.
TL;DR: In this article, ion-microprobe measurements of the carbon-isotope composition of carbonaceous inclusions within grains of apatite (basic calcium phosphate) from the oldest known sediment sequences a approx. 3,800 Myr-old banded iron formation from the Isua supracrustal belt, West Greenland and a similar formation from Akilia island that is possibly older than 3,850 Myr.
Abstract: It is unknown when life first appeared on Earth. The earliest known microfossils (approx. 3,500 Myr before present) are structurally complex, and if it is assumed that the associated organisms required a long time to develop this degree of complexity, then the existence of life much earlier than this can be argued. But the known examples of crustal rocks older than approx. 3,500 Myr have experienced intense metamorphism, which would have obliterated any fragile microfossils contained therein. It is therefore necessary to search for geochemical evidence of past biotic activity that has been preserved within minerals that are resistant to metamorphism. Here we report ion-microprobe measurements of the carbon-isotope composition of carbonaceous inclusions within grains of apatite (basic calcium phosphate) from the oldest known sediment sequences a approx. 3,800 Myr-old banded iron formation from the Isua supracrustal belt, West Greenland, and a similar formation from the nearby Akilia island that is possibly older than 3,850 Myr. The carbon in the carbonaceous inclusions is isotopically light, indicative of biological activity; no known abiotic process can explain the data. Unless some unknown abiotic process exists which is able both to create such isotopically light carbon and then selectively incorporate it into apatite grains, our results provide evidence for the emergence of life on Earth by at least 3,800 Myr before present.
12 May 1996
TL;DR: An RSA-based signing scheme which combines essentially optimal efficiency with attractive security properties and a second scheme which maintains all of the above features and in addition provides message recovery is provided.
Abstract: We describe an RSA-based signing scheme which combines essentially optimal efficiency with attractive security properties. Signing takes one RSA decryption plus some hashing, verification takes one RSA encryption plus some hashing, and the size of the signature is the size of the modulus. Assuming the underlying hash functions are ideal, our schemes are not only provably secure, but are so in a tight way-- an ability to forge signatures with a certain amount of computational resources implies the ability to invert RSA (on the same size modulus) with about the same computational effort. Furthermore, we provide a second scheme which maintains all of the above features and in addition provides message recovery. These ideas extend to provide schemes for Rabin signatures with analogous properties; in particular their security can be tightly related to the hardness of factoring.
TL;DR: Whereas activation of each receptor alone resulted in modest activation of JNK, coadministration of EGF, IL-1, and TNF resulted in a strong synergistic response equal to that caused by exposure to osmotic shock or UV light, inhibition of clustering or receptor down-regulation attenuated both the osmosis shock and UV responses.
Abstract: Exposure of mammalian cells to ultraviolet (UV) light or high osmolarity strongly activates the c-Jun amino-terminal protein kinase (JNK) cascade, causing induction of many target genes. Exposure to UV light or osmotic shock induced clustering and internalization of cell surface receptors for epidermal growth factor (EGF), tumor necrosis factor (TNF), and interleukin-1 (IL-1). Activation of the EGF and TNF receptors was also detected biochemically. Whereas activation of each receptor alone resulted in modest activation of JNK, coadministration of EGF, IL-1, and TNF resulted in a strong synergistic response equal to that caused by exposure to osmotic shock or UV light. Inhibition of clustering or receptor down-regulation attenuated both the osmotic shock and UV responses. Physical stresses may perturb the cell surface or alter receptor conformation, thereby subverting signaling pathways normally used by growth factors and cytokines.
TL;DR: Clinical studies in patients with type II diabetes, as well as other syndromes characterized by insulin resistance, have demonstrated that thiazolidinediones may represent a safe and effective new treatment.
Abstract: Insulin resistance, characterized by reduced responsiveness to normal circulating concentrations of insulin, is a common feature of almost all patients with type II diabetes. The presumed central roles of both peripheral and hepatic insulin resistance suggest that the enhancement of insulin action might be an effective pharmacological approach to diabetes. Thiazolidinediones are a new class of orally active drugs that are designed to enhance the actions of insulin. These agents reduce insulin resistance by increasing insulin-dependent glucose disposal and reducing hepatic glucose output. Clinical studies in patients with type II diabetes, as well as other syndromes characterized by insulin resistance, have demonstrated that thiazolidinediones may represent a safe and effective new treatment. Although the precise mechanism of action of these drugs remains unknown, transcriptional changes are observed in tissue culture cells that produce enhanced insulin action. This regulation of gene expression appears to be mediated by the interactions of thiazolidinediones with a family of nuclear receptors known as the peroxisome proliferator-activated receptors (PPARs). The further elucidation of the molecular actions of these drugs may reveal much about the underlying mechanisms of insulin resistance.
TL;DR: The CATCH intervention was able to modify the fat content of school lunches, increase moderate-to-vigorous physical activity in PE, and improve eating and physical activity behaviors in children during 3 school years.
Abstract: grade intervention including school food service modifications, enhanced physical education (PE), and classroom health curricula. Twenty-eight additional schools received these components plus family education. Main Outcome Measures.\p=m-\Atthe school level, the two primary end points were changes in the fat content of food service lunch offerings and the amount of moderate-to-vigorous physical activity in the PE programs. At the level of the individual student, serum cholesterol change was the primary end point and was used for power calculations for the study. Individual level secondary end points included psychosocial factors, recall measures of eating and physical activity patterns, and other physiologic measures. Results.\p=m-\Inintervention school lunches, the percentage of energy intake from fat fell significantly more (from 38.7% to 31.9%) than in control lunches (from 38.9% to 36.2%)(P<.001 ). The intensity of physical activity in PE classes during the Child and Adolescent Trial for Cardiovascular Health (CATCH) intervention increased significantly in the intervention schools compared with the control schools (P<.02). Self-reported daily energy intake from fat among students in the intervention schools was significantly reduced (from 32.7% to 30.3%) compared with that among students in the control schools (from 32.6% to 32.2%) (P<.001). Intervention students reported significantly more daily vigorous activity than controls (58.6 minutes vs 46.5 minutes; P<.003). Blood pressure, body size, and cholesterol measures did not differ significantly between treatment groups. No evidence of deleterious effects of this intervention on growth or development was observed. Conclusion.\p=m-\TheCATCH intervention was able to modify the fat content of school lunches, increase moderate-to-vigorous physical activity in PE, and improve eating and physical activity behaviors in children during 3 school years.
TL;DR: Low-intensity, fixed-dose warfarin plus aspirin in this regimen is insufficient for stroke prevention in patients with non-valvular AF at high-risk for thromboembolism; adjusted-doseWarfarin (target INR 2.0-3.0) importantly reduces stroke for high- risk patients.
TL;DR: In this paper, a virtual reality box is used to simulate the feeling of a real arm being touched by a real hand in order to study the inter-sensory effects of visual input on the phantom.
Abstract: Although there is a vast clinical literature on phantom limbs, there have been no experimental studies on the effects of visual input on phantom sensations. We introduce an inexpensive new device--a 'virtual reality box'--to resurrect the phantom visually to study inter-sensory effects. A mirror is placed vertically on the table so that the mirror reflection of the patient's intact had is 'superimposed' on the felt position of the phantom. We used this procedure on ten patients and found the following results. 1. In six patients, when the normal hand was moved, so that the phantom was perceived to move in the mirror, it was also felt to move; i.e. kinesthetic sensations emerged in the phantom. In D.S. this effect occurred even though he had never experienced any movements in the phantom for ten years before we tested him. He found the return of sensations very enjoyable. 2. Repeated practice led to a permanent 'disappearance' of the phantom arm in patient D.S. and the hand became telescoped into the stump near the shoulder. 3. Using an optical trick, impossible postures--e.g. extreme hyperextension of the fingers--could be induced visually in the phantom. In one case this was felt as a transient 'painful tug' in the phantom. 4. Five patients experienced involuntary painful 'clenching spasms' in the phantom hand and in four of them the spasms were relieved when the mirror was used to facilitate 'opening' of the phantom hand; opening was not possible without the mirror. 5. In three patients, touching the normal hand evoked precisely localized touch sensations in the phantom. Interestingly, the referral was especially pronounced when the patients actually 'saw' their phantom being touched in the mirror. Indeed, in a fourth patient (R.L.) the referral occurred only if he saw his phantom being touched: a curious form of synaesthesia. These experiments lend themselves readily to imaging studies using PET and fMRI. Taken collectively, they suggest that there is a considerable amount of latent plasticity even in the adult human brain. For example, precisely organized new pathways, bridging the two cerebral hemispheres, can emerge in less than three weeks. Furthermore, there must be a great deal of back and forth interaction between vision and touch, so that the strictly modular, hierarchical model of the brain that is currently in vogue needs to be replaced with a more dynamic, interactive model, in which 're-entrant' signalling plays the main role.
TL;DR: In this article, a double-blind study evaluated treatment with either a single nucleoside or two nucleosides in adults infected with human immunodeficiency virus type 1 (HIV-1) whose CD4 cell counts were from 200 to 500 per cubic millimeter.
Abstract: Background This double-blind study evaluated treatment with either a single nucleoside or two nucleosides in adults infected with human immunodeficiency virus type 1 (HIV-1) whose CD4 cell counts were from 200 to 500 per cubic millimeter. Methods We randomly assigned 2467 HIV-1–infected patients (43 percent without prior antiretroviral treatment) to one of four daily regimens: 600 mg of zidovudine; 600 mg of zidovudine plus 400 mg of didanosine; 600 mg of zidovudine plus 2.25 mg of zalcitabine; or 400 mg of didanosine. The primary end point was a >50 percent decline in the CD4 cell count, development of the acquired immunodeficiency syndrome (AIDS), or death. Results Progression to the primary end point was more frequent with zidovudine alone (32 percent) than with zidovudine plus didanosine (18 percent; relative hazard ratio, 0.50; P<0.001), zidovudine plus zalcitabine (20 percent; relative hazard ratio, 0.54; P<0.001), or didanosine alone (22 percent; relative hazard ratio, 0.61; P<0.001). The relative ...
TL;DR: Results indicate that aP2 is central to the pathway that links obesity to insulin resistance, possibly by linking fatty acid metabolism to expression of TNF-α.
Abstract: Fatty acid binding proteins (FABPs) are small cytoplasmic proteins that are expressed in a highly tissue-specific manner and bind to fatty acids such as oleic and retinoic acid. Mice with a null mutation in aP2 , the gene encoding the adipocyte FABP, were developmentally and metabolically normal. The aP2 -deficient mice developed dietary obesity but, unlike control mice, they did not develop insulin resistance or diabetes. Also unlike their obese wild-type counterparts, obese aP2 −/− animals failed to express in adipose tissue tumor necrosis factor-α (TNF-α), a molecule implicated in obesity-related insulin resistance. These results indicate that aP2 is central to the pathway that links obesity to insulin resistance, possibly by linking fatty acid metabolism to expression of TNF-α.
TL;DR: The model offers a specific one-dimensional example of a computational mechanism in which a truly world-centered representation can be derived from observer-centered sensory inputs by integrating self-motion information.
Abstract: The head-direction (HD) cells found in the limbic system in freely mov ing rats represent the instantaneous head direction of the animal in the horizontal plane regardless of the location of the animal. The internal direction represented by these cells uses both self-motion information for inertially based updating and familiar visual landmarks for calibration. Here, a model of the dynamics of the HD cell ensemble is presented. The stability of a localized static activity profile in the network and a dynamic shift mechanism are explained naturally by synaptic weight distribution components with even and odd symmetry, respectively. Under symmetric weights or symmetric reciprocal connections, a stable activity profile close to the known directional tuning curves will emerge. By adding a slight asymmetry to the weights, the activity profile will shift continuously without disturbances to its shape, and the shift speed can be controlled accurately by the strength of the odd-weight component. The generic formulation of the shift mechanism is determined uniquely within the current theoretical framework. The attractor dynamics of the system ensures modality- independence of the internal representation and facilitates the correction for cumulative error by the putative local-view detectors. The model offers a specific one-dimensional example of a computational mechanism in which a truly world-centered representation can be derived from observer-centered sensory inputs by integrating self-motion information.
12 May 1996
TL;DR: This work examplify the verifier designation method for the confirmation protocol for undeniable signatures, and demonstrates how a trap-door commitment scheme can be used to construct designated verifier proofs, both interactive and non-interactive.
Abstract: For many proofs of knowledge it is important that only the verifier designated by the confirmer can obtain any conviction of the correctness of the proof. A good example of such a situation is for undeniable signatures, where the confirmer of a signature wants to make sure that only the intended verifier(s) in fact can be convinced about the validity or invalidity of the signature.
Generally, authentication of messages and off-the-record messages are in conflict with each other. We show how, using designation of verifiers, these notions can be combined, allowing authenticated but private conversations to take place. Our solution guarantees that only the specified verifier can be convinced by t,he proof, even if he shares all his secret information with entities that want to get convinced.
Our solution is based on trap-door conim.itments [4], allowing the designated verifier to open up commitments in any way he wants. We demonstrate how a trap-door commitment scheme can be uscd to construct designated verifier proofs, both interactive and non-interactive. We examplify the verifier designation method for the confirmation protocol for undeniable signatures.
TL;DR: In this article, a general class of long memory models that has no memory in returns themselves but long memory in absolute returns and their power transformations is proposed and the Monte Carlo simulation shows that the theoretical model can mimic the stylized empirical facts strikingly well.
TL;DR: Cities and Citizenship as discussed by the authors is a prize-winning collection of essays that considers the importance of cities in the making of modern citizens and argues that cities are crucial places for the development of new alignments of local and global identity.
Abstract: Cities and Citizenship is a prize-winning collection of essays that considers the importance of cities in the making of modern citizens. For most of the modern era the nation and not the city has been the principal domain of citizenship. This volume demonstrates, however, that cities are especially salient sites for examining the current renegotiations of citizenship, democracy, and national belonging.
Just as relations between nations are changing in the current phase of global capitalism, so too are relations between nations and cities. Written by internationally prominent scholars, the essays in Cities and Citizenship propose that “place” remains fundamental to these changes and that cities are crucial places for the development of new alignments of local and global identity. Through case studies from Africa, Europe, Latin America, and North America, the volume shows how cities make manifest national and transnational realignments of citizenship and how they generate new possibilities for democratic politics that transform people as citizens. Previously published as a special issue of Public Culture that won the 1996 Best Single Issue of a Journal Award from the Professional/Scholarly Publishing Division of the Association of American Publishers, the collection showcases a photo essay by Cristiano Mascaro, as well as two new essays by James Holston and Thomas Bender.
Cities and Citizenship will interest students and scholars of anthropology, geography, sociology, planning, and urban studies, as well as globalization and political science.
Contributors . Arjun Appadurai, Etienne Balibar, Thomas Bender, Teresa P. R. Caldeira, Mamadou Diouf, Dilip Parameshwar Gaonkar, James Holston, Marco Jacquemet, Christopher Kamrath, Cristiano Mascaro, Saskia Sassen, Michael Watts, Michel Wieviorka
TL;DR: The Arabidopsis DET2 gene encodes a protein that shares significant sequence identity with mammalian steroid 5α-reductases, and brassinosteroids may constitute a distinct class of phytohormones with an important role in light-regulated development of higher plants.
Abstract: Although steroid hormones are important for animal development, the physiological role of plant steroids is unknown The Arabidopsis DET2 gene encodes a protein that shares significant sequence identity with mammalian steroid 5α-reductases A mutation of glutamate 204, which is absolutely required for the activity of human steroid reductase, abolishes the in vivo activity of DET2 and leads to defects in light-regulated development that can be ameliorated by application of a plant steroid, brassinolide Thus, DET2 may encode a reductase in the brassinolide biosynthetic pathway, and brassinosteroids may constitute a distinct class of phytohormones with an important role in light-regulated development of higher plants