bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Role of Pathogen Signaling in Multitrophic Plant-Microbe Interactions Involved in Disease Protection
Authors: Duffy Brion , Keel Christoph , Défago Geneviève
Published: March 2004

Multitrophic interactions mediate the ability of fungal pathogens to cause plant disease and the ability of bacterial antagonists to suppress disease. Antibiotic production by antagonists, which contributes to disease suppression, is known to be modulated by abiotic and host plant environmental conditions. Here, we demonstrate that a pathogen metabolite functions as a negative signal for bacterial antibiotic biosynthesis, which can determine the relative importance of biological control mechanisms available to antagonists and which may also influence fungus-bacterium ecological interactions. We found that production of the polyketide antibiotic 2,4-diacetylphloroglucinol (DAPG) was the primary biocontrol mechanism of
Pseudomonas fluorescens
strain Q2-87 against
Fusarium oxysporum
f. sp.
radicis-lycopersici
on the tomato as determined with mutational analysis. In contrast, DAPG was not important for the less-disease-suppressive strain CHA0. This was explained by differential sensitivity of the bacteria to fusaric acid, a pathogen phyto- and mycotoxin that specifically blocked DAPG biosynthesis in strain CHA0 but not in strain Q2-87. In CHA0, hydrogen cyanide, a biocide not repressed by fusaric acid, played a more important role in disease suppression.
Reappraisal of the Regulation of Lactococcal
l
-Lactate Dehydrogenase
Authors: van Niel Ed W. J. , Palmfeldt Johan , Martin Rani , Paese Marco , Hahn-Hägerdal Bärbel
Published: March 2004

Lactococcal lactate dehydrogenases (LDHs) are coregulated at the substrate level by at least two mechanisms: the fructose-1,6-biphosphate/phosphate ratio and the NADH/NAD ratio. Among the
Lactococcus lactis
species, there are strains that are predominantly regulated by the first mechanism (e.g., strain 65.1) or by the second mechanism (e.g., strain NCDO 2118). A more complete model of the kinetics of the regulation of lactococcal LDH is discussed.
Differential Expression of
Desulfovibrio vulgaris
Genes in Response to Cu(II) and Hg(II) Toxicity
Authors: Chang In Seop , Groh Jennifer L. , Ramsey Matthew M. , Ballard Jimmy D. , Krumholz Lee R.
Published: March 2004

The response of
Desulfovibrio vulgaris
to Cu(II) and Hg(II) was characterized. Both metals increased the lag phase, and Cu(II) reduced cell yield at concentrations as low as 50 μM. mRNA expression was analyzed using random arbitrarily primed PCR, differential display, and quantitative PCR. Both Cu(II) and Hg(II) (50 μM) caused upregulation of mRNA expression for an ATP binding protein (ORF2004) and an ATPase (ORF856) with four- to sixfold increases for Hg(II) and 1.4- to 3-fold increases with Cu(II). These results suggest that
D. vulgaris
uses an ATP-dependent mechanism for adapting to toxic metals in the environment.
In Planta Production of Indole-3-Acetic Acid by
Colletotrichum gloeosporioides
f. sp.
aeschynomene
Authors: Maor Rudy , Haskin Sefi , Levi-Kedmi Hagit , Sharon Amir
Published: March 2004

The plant pathogenic fungus
Colletotrichum gloeosporioides
f. sp
. aeschynomene
utilizes external tryptophan to produce indole-3-acetic acid (IAA) through the intermediate indole-3-acetamide (IAM). We studied the effects of tryptophan, IAA, and IAM on IAA biosynthesis in fungal axenic cultures and on in planta IAA production by the fungus. IAA biosynthesis was strictly dependent on external tryptophan and was enhanced by tryptophan and IAM. The fungus produced IAM and IAA in planta during the biotrophic and necrotrophic phases of infection. The amounts of IAA produced per fungal biomass were highest during the biotrophic phase. IAA production by this plant pathogen might be important during early stages of plant colonization.
Evaluation of a Real-Time PCR Kit for Detecting
Escherichia coli
O157 in Bovine Fecal Samples
Authors: Bono James L. , Keen James E. , Miller Laura C. , Fox James M. , Chitko-McKown Carol G. , Heaton Michael P. , Laegreid William W.
Published: March 2004

A commercially available real-time, rapid PCR test was evaluated for its ability to detect
Escherichia coli
O157. Both the sensitivity and specificity of the assay were 99% for isolates in pure culture. The assay detected 1 CFU of
E. coli
O157:H7 g
−1
in artificially inoculated bovine feces following enrichment.
thyA
as a Selection Marker in Construction of Food-Grade Host-Vector and Integration Systems for
Streptococcus thermophilus
Authors: Sasaki Yasuko , Ito Yoshiyuki , Sasaki Takashi
Published: March 2004

We constructed food-grade host-vector and integration systems for
Streptococcus thermophilus
by using a thymidylate synthase gene (
thyA
) as the selection marker. Two
thyA
genes,

thyA
St

and

thyA
Lb

, were cloned from
S. thermophilus
and
Lactobacillus delbrueckii
subsp.
bulgaricus
, respectively. Thymidine-requiring mutants of
S. thermophilus
were obtained after successive cultures in the presence of trimethoprim, and one of them, TM1-1, was used as the host. Food-grade vectors were constructed by using either

thyA
St

or

thyA
Lb

as the selection marker. Transformants of TM1-1 created by using these vectors were selected for thymidine autotrophy as efficiently as for erythromycin resistance. By using the host-vector system developed in this way, a foreign amylase gene (
amyA
) was expressed in TM1-1 and was also integrated into the chromosome by use of a temperature-sensitive integration vector constructed with

thyA
Lb

as the selection marker via a double-crossover event. The results obtained show that
thyA
is an efficient and safe selection marker for
S. thermophilus
that is suitable for food applications.
Arsenite-Oxidizing
Hydrogenobaculum
Strain Isolated from an Acid-Sulfate-Chloride Geothermal Spring in Yellowstone National Park
Authors: Donahoe-Christiansen Jessica , D'Imperio Seth , Jackson Colin R. , Inskeep William P. , McDermott Timothy R.
Published: March 2004

An arsenite-oxidizing
Hydrogenobaculum
strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H
2
as its sole energy source and had an optimum temperature of 55 to 60°C and an optimum pH of 3.0. The arsenite oxidation in this organism displayed saturation kinetics and was strongly inhibited by H
2
S.
l
-Alanine Auxotrophy of
Lactobacillus johnsonii
as Demonstrated by Physiological, Genomic, and Gene Complementation Approaches
Authors: van der Kaaij Hengameh , Desiere Frank , Mollet Beat , Germond Jacques-Edouard
Published: March 2004

Using a chemically defined medium without
l
-alanine,
Lactobacillus johnsonii
was demonstrated to be strictly auxotrophic for that amino acid. A comparative genetic analysis showed that all known genes involved in
l
-alanine biosynthesis are absent from the genome of
L. johnsonii
. This auxotrophy was complemented by heterologous expression of the
Bacillus subtilis
l
-alanine dehydrogenase.
Nocardia
sp. Carboxylic Acid Reductase: Cloning, Expression, and Characterization of a New Aldehyde Oxidoreductase Family
Authors: He Aimin , Li Tao , Daniels Lacy , Fotheringham Ian , Rosazza John P. N.
Published: March 2004

We have cloned, sequenced, and expressed the gene for a unique ATP- and NADPH-dependent carboxylic acid reductase (CAR) from a
Nocardia
species that reduces carboxylic acids to their corresponding aldehydes. Recombinant CAR containing an N-terminal histidine affinity tag had

K
m

values for benzoate, ATP, and NADPH that were similar to those for natural CAR, and recombinant CAR reduced benzoic, vanillic, and ferulic acids to their corresponding aldehydes.
car
is the first example of a new gene family encoding oxidoreductases with remote acyl adenylation and reductase sites.
Lessons from the Genome Sequence ofNeurospora crassa: Tracing the Path from Genomic Blueprint to Multicellular Organism
Authors: Borkovich Katherine A. , Alex Lisa A. , Yarden Oded , Freitag Michael , Turner Gloria E. , Read Nick D. , Seiler Stephan , Bell-Pedersen Deborah , Paietta John , Plesofsky Nora , Plamann Michael , Goodrich-Tanrikulu Marta , Schulte Ulrich , Mannhaupt Gertrud , Nargang Frank E. , Radford Alan , Selitrennikoff Claude , Galagan James E. , Dunlap Jay C. , Loros Jennifer J. , Catcheside David , Inoue Hirokazu , Aramayo Rodolfo , Polymenis Michael , Selker Eric U. , Sachs Matthew S. , Marzluf George A. , Paulsen Ian , Davis Rowland , Ebbole Daniel J. , Zelter Alex , Kalkman Eric R. , O'Rourke Rebecca , Bowring Frederick , Yeadon Jane , Ishii Chizu , Suzuki Keiichiro , Sakai Wataru , Pratt Robert
Published: March 2004

We present an analysis of over 1,100 of the ∼10,000 predicted proteins encoded by the genome sequence of the filamentous fungusNeurospora crassa. Seven major areas ofNeurosporagenomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion ofNeurosporagenes do not have homologues in the yeastsSaccharomyces cerevisiaeandSchizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease.
Eukaryotic MCM Proteins: Beyond Replication Initiation
Authors: Forsburg Susan L.
Published: March 2004

The minichromosome maintenance (or MCM) protein family is composed of six related proteins that are conserved in all eukaryotes. They were first identified by genetic screens in yeast and subsequently analyzed in other experimental systems using molecular and biochemical methods. Early data led to the identification of MCMs as central players in the initiation of DNA replication. More recent studies have shown that MCM proteins also function in replication elongation, probably as a DNA helicase. This is consistent with structural analysis showing that the proteins interact together in a heterohexameric ring. However, MCMs are strikingly abundant and far exceed the stoichiometry of replication origins; they are widely distributed on unreplicated chromatin. Analysis ofmcmmutant phenotypes and interactions with other factors have now implicated the MCM proteins in other chromosome transactions including damage response, transcription, and chromatin structure. These experiments indicate that the MCMs are central players in many aspects of genome stability.
Diversity of Microbial Sialic Acid Metabolism
Authors: Vimr Eric R. , Kalivoda Kathryn A. , Deszo Eric L. , Steenbergen Susan M.
Published: March 2004

Sialic acids are structurally unique nine-carbon keto sugars occupying the interface between the host and commensal or pathogenic microorganisms. An important function of host sialic acid is to regulate innate immunity, and microbes have evolved various strategies for subverting this process by decorating their surfaces with sialylated oligosaccharides that mimic those of the host. These subversive strategies include a de novo synthetic pathway and at least two truncated pathways that depend on scavenging host-derived intermediates. A fourth strategy involves modification of sialidases so that instead of transferring sialic acid to water (hydrolysis), a second active site is created for binding alternative acceptors. Sialic acids also are excellent sources of carbon, nitrogen, energy, and precursors of cell wall biosynthesis. The catabolic strategies for exploiting host sialic acids as nutritional sources are as diverse as the biosynthetic mechanisms, including examples of horizontal gene transfer and multiple transport systems. Finally, as compounds coating the surfaces of virtually every vertebrate cell, sialic acids provide information about the host environment that, at least in
Escherichia coli
, is interpreted by the global regulator encoded by
nanR
. In addition to regulating the catabolism of sialic acids through the
nan
operon, NanR controls at least two other operons of unknown function and appears to participate in the regulation of type 1 fimbrial phase variation. Sialic acid is, therefore, a host molecule to be copied (molecular mimicry), eaten (nutrition), and interpreted (cell signaling) by diverse metabolic machinery in all major groups of mammalian pathogens and commensals.
Iron Transport Systems in
Neisseria meningitidis
Authors: Perkins-Balding Donna , Ratliff-Griffin Melanie , Stojiljkovic Igor
Published: March 2004

Acquisition of iron and iron complexes has long been recognized as a major determinant in the pathogenesis of
Neisseria meningitidis
. In this review, high-affinity iron uptake systems, which allow meningococci to utilize the human host proteins transferrin, lactoferrin, hemoglobin, and haptoglobin-hemoglobin as sources of essential iron, are described. Classic features of bacterial iron transport systems, such as regulation by the iron-responsive repressor Fur and TonB-dependent transport activity, are discussed, as well as more specific features of meningococcal iron transport. Our current understanding of how
N. meningitidis
acquires iron from the human host and the vaccine potentials of various components of these iron transport systems are also reviewed.
CHARGED DOMAIN WALLS
Authors: CAMPANELLI L. , CEA P. , FOGLI G. L. , TEDESCO L.
Published: March 2004

In this paper we investigate Charged Domain Walls (CDW's), topological defects that acquire surface charge density Q induced by fermion states localized on the walls. The presence of an electric and magnetic field on the walls is also discussed. We find a relation in which the value of the surface charge density Q is connected with the existence of such topological defects.
COSMOLOGICAL PERTURBATIONS IN RENORMALIZATION GROUP DERIVED COSMOLOGIES
Authors: BONANNO A. , REUTER M.
Published: March 2004

A linear cosmological perturbation theory of an almost homogeneous and isotropic perfect fluid Universe with dynamically evolving Newton constant G and cosmological constant Λ is presented. A gauge invariant formalism is developed by means of the covariant approach, and the acoustic propagation equations governing the evolution of the comoving fractional spatial gradients of the matter density, G, and Λ are thus obtained. Explicit solutions are discussed in cosmologies where both G and Λ vary according to renormalization group equations in the vicinity of a fixed point.
RELATIVISTIC, CAUSAL DESCRIPTION OF QUANTUM ENTANGLEMENT AND GRAVITY
Authors: MOFFAT J. W.
Published: March 2004

A possible solution to the problem of providing a spacetime description of the transmission of signals for quantum entangled states is obtained by using a bimetric spacetime structure, in which quantum entanglement measurements alter the structure of the classical relativity spacetime. A bimetric gravity theory locally has two lightcones, one which describes classical special relativity and a larger lightcone which allows light signals to communicate quantum information between entangled states, after a measurement device detects one of the entangled quantum states. This theory would remove the tension that exists between macroscopic classical, local gravity and macroscopic nonlocal quantum mechanics.
SELF-CREATING BRANE WORLDS
Authors: GONZÁLEZ-DÍAZ PEDRO F. , CARRIÓN JUAN MARTÍN
Published: March 2004

Several boundary conditions for the universe have been hitherto suggested, basing on different philosophical approaches. In particular, one may choose between the notions that the universe was created either from nothing or by itself. The quantum state of a universe created from nothing has been already formulated under distinct standpoints by Hartle, Hawking, Vilenkin and others. In this paper we have concentrated on deriving a quantum theory for a self-created universe. Thus, we have first considered the spacetime structure of a six-dimensional de Sitter space with a multiply connected region and, by using a cutting and pasting procedure, we have then been able to show that one can introduce a four-brane in such a spacetime whose evolution can also be considered within the context of ekpyrotic and cyclic universes, and quantized in terms of the sum-over-histories formulation, according to the rules of the generalized quantum theory developed by Hartle.
CAUSAL CONFIGURATIONS OF HOMOGENEOUS ENERGY DENSITY IN GENERAL RELATIVITY
Authors: NEGI P. S.
Published: March 2004

If the causality condition [the speed of sound always remains less than that of light in vacuum, i.e. v≤c=1] is imposed on the spheres of homogeneous energy density, the "ratio of the specific heats", γ≤2.59457, constraints the compaction parameter, u[≡(M/a), mass to size ratio in geometrized units] of the dynamically stable configurations ≤0.34056 [corresponding to a surface redshift (za)≤0.771]. Apparently, the maximum value of u obtained in this manner belongs to an absolute upper bound, and gives: (i) The maximum value for static neutron star masses as 5.4 M⊙, if we substitute the density at the surface of the configuration equal to the average nuclear density, E=2×1014 g cm -3 [e.g. Nature, 259, 377 (1976)]. (ii) However, if the density of the static configuration is constrained to the value 1.072×1014 g cm -3, by imposing the empirical result that the minimum rotation period of the fastest rotating pulsar known to date, PSR 1937+21, is 1.558 ms, the maximum mass value for static neutron stars exceed upto 7.4 M⊙. These masses have important implications for the massive compact objects, such as Cyg X-1, Cyg XR-1, LMC-X3, etc., which may not, necessarily, represent black holes. (iii) The minimum rotation periods for a static 1.442 M⊙ neutron star to be 0.3041 ms. (iv) A suitable stable model of ultra-compact objects [u>(1/3)] which has important astrophysical significance.
GRADIENT PERCOLATION AND FRACTAL FRONTIERS IN IMAGE PROCESSING
Authors: SAPOVAL B. , ROSSO M.
Published: March 2004

In contrast to standard percolation where criticality is reached only for a particular value pc of the driving parameter p, gradient percolation exists without the precise tuning of a percolation parameter. For this reason it may be a common physical situation. Very generally, gradient percolation will appear in a uniform system whenever there exists a local random response to an excitation which varies in space. We show that such a situation exists in the example of photographic imaging, due to the random aspect of the photographic process. In this case gradient percolation may be used as a filter for recovering fuzzy images. This filter has the advantage of self-adjusting and to be neutral in regard to the size of the objects. In particular it could be used to increase artificially the depth of focus on photographs that are partially fuzzy.
RANDOMNESS IN AIRBORNE POLLEN: CHAOS OR NOISE?
Authors: ARIZMENDI C.M. , SANCHEZ J.R. , FOTI M.A.
Published: March 2004

The most abundant biological particles in the atmosphere are pollen grains and spores. Previous analyses of the dynamic characteristics of atmospheric pollen time series based on the study of the correlation dimension indicate that the system can be described by a low dimensional chaotic map. As the determination of a fractal dimension is not completely reliable, a less ambitious but secure task is to find the nonlinear character of the time series. A recently developed method to distinguish nonlinear deterministic systems from linear stochastic systems is applied to a pollen time series of about 8000 values. The nonlinear structure of the series is obtained.
Gender and Inequality in the Global Labor Force
Authors: Mills Mary Beth
Published: March 2004

▪ Abstract  This review examines the convergence of recent anthropological interests in gender, labor, and globalization. Attention to gender and gender inequality offers a productive strategy for the analysis of globalizing processes and their local variations and contestations. Contemporary ethnographic research explores multiple dimensions of labor and gender inequalities in the global economy: gendered patterns of labor recruitment and discipline, the transnational mobility and commodification of reproductive labor, and the gendered effects of international structural adjustment programs, among others. New and continuing research explores the diverse meanings and practices that produce a gendered global labor force, incorporating the perspectives of men and women, masculinities and femininities, and examines how these processes of gender and labor inequality articulate with other structures of subordination (such as ethnicity and nationality) to shape lived experiences of work and livelihood, exploitation and struggle, around the world.
Resource Wars: The Anthropology of Mining
Authors: Ballard Chris , Banks Glenn
Published: March 2004

▪ Abstract  The scope for an anthropology of mining has been dramatically transformed since the review by Ricardo Godoy, published in this review journal in 1985. The minerals boom of the 1980s led to an aggressive expansion of mine development in greenfield areas, many of them the domains of indigenous communities. Under considerable pressure, the conventional binary contest between states and corporations over the benefits and impacts of mining has been widened to incorporate the representations of local communities, and broad but unstable mining communities now coalesce around individual projects. Focused primarily on projects in developing nations of the Asia-Pacific region, this review questions the often-monolithic characterizations of state, corporate, and community forms of agency and charts the debate among anthropologists involved in mining, variously as consultants, researchers, and advocates, about appropriate terms for their engagement.
The Neolithic Invasion of Europe
Authors: Richards Martin
Published: March 2004

▪ Abstract  Who are Europeans? Both prehistoric archaeology and, subsequently, classical population genetics have attempted to trace the ancestry of modern Europeans back to the first appearance of agriculture in the continent; however, the question has remained controversial. Classical population geneticists attributed the major pattern in the European gene pool to the demographic impact of Neolithic farmers dispersing from the Near East, but archaeological research has failed to uncover substantial evidence for the population growth that is supposed to have driven this process. Recently, molecular approaches, using non-recombining genetic marker systems, have introduced a chronological dimension by both allowing the tracing of lineages back through time and dating using the molecular clock. Both mitochondrial DNA and Y-chromosome analyses have indicated a contribution of Neolithic Near Eastern lineages to the gene pool of modern Europeans of around a quarter or less. This suggests that dispersals bringing the Neolithic to Europe may have been demographically minor and that contact and assimilation had an important role.
Developmental Biology and Human Evolution
Authors: Lovejoy C. Owen , McCollum Melanie A. , Reno Philip L. , Rosenman Burt A.
Published: March 2004

▪ Abstract  Our understanding of developmental biology burgeoned during the last decade. This review summarizes recent advances, provides definitions and explanations of some basic principles, and does so in a way that will aid anthropologists in understanding their profound implications. Crucial concepts, such as developmental fields, selector and realizator genes, cell signaling mechanisms, and gene regulatory elements are briefly described and then integrated with the emergence of skeletal morphology. For the postcranium, a summary of events from limb bud formation, the appearance of anlagen, the expression of Hox genes, and the fundamentals of growth plate dynamics are briefly summarized. Of particular importance are revelations that bony morphology is largely determined by pattern formation, that growth foci such as physes and synovial joints appear to be regulated principally by positional information, and that variation in these fields is most likely determined by cis-regulatory elements acting on restricted numbers of anabolic genes downstream of selectors (such as Hox). The implications of these discoveries for the interpretation of both contemporary and ancient human skeletal morphology are profound. One of the most salient is that strain transduction now appears to play a much reduced role in shaping the human skeleton. Indeed, the entirety of “Wolff's Law” must now be reassessed in light of new knowledge about pattern formation. The review concludes with a brief discussion of some implications of these findings, including their impact on cladistics and homology, as well as on biomechanical and morphometric analyses of both ancient and modern human skeletal material.
Hunter-Gatherer Archaeology in South America
Authors: Scheinsohn Vivian
Published: March 2004

▪ Abstract  A general overview of hunter-gatherer archaeology in South America is given by recognizing the main problems in a South American context. Environmental framework and Paleoecological changes are summarized. Pleistocene and Holocene archaeology is reviewed in terms of these particularities. With respect to the Pleistocene, I review Pre-Clovis human presence in South America, technological differences between North and South America, variability in South American subsistence strategy, colonization and demographic models, and migratory routes. The Holocene archaeology is divided into Early and Late. For the former, I consider establishment of adaptive strategies (as marine adaptations), new artifact designs, and mortuary behaviors. For the latter, I consider exchange networks, emergence of complex hunter gatherers, mortuary behavior, origins of food production, and the contact with European populations.
Mississippian Chiefdoms: How Complex?
Authors: Cobb Charles R.
Published: March 2004

▪ Abstract  During the Mississippian period (a.d. 1000–1500) the southeastern United States witnessed a broadscale fluorescence of polities characterized by impressive earthwork construction, rich mortuary offerings, and intensified agriculture. Research on the nature of complexity in these so-called chiefdoms has been an enduring issue in North American archaeology, even as this research has undergone several paradigmatic shifts. This study focuses on the primary dimensions of the archaeological record used to describe and explain variation in Mississippian complexity—polity scale, settlement and landscape, the organization of labor, mortuary ritual and ideology, and tribute and feasting. Changing perspectives toward the organization of complexity and power have become increasingly pronounced in each of these categories.
In Pursuit of Culture
Authors: Goodenough Ward H.
Published: March 2004

▪ Abstract  In this brief, autobiographical account, I trace the development of my intellectual and theoretical interests, especially as they relate to culture. How can we account for culture's being learned by individuals and yet apparently shared by members of a community? How do cultures as shared within communities change and evolve? How does what we know about languages, themselves a kind of cultural tradition, contribute to understanding culture and cultural evolution? Are processes of cultural and linguistic evolution analogous to those in the evolution of biological species and, if so, in what ways? How, also, do genetically based behavioral proclivities manifest themselves in social arenas that are structured by language and culture?
It's A Material World: History, Artifacts, and Anthropology
Authors: Brumfiel Elizabeth M.
Published: March 2004

▪ Abstract  History is of critical importance for anthropology because, in human affairs, the present is intimately linked to the past. Archaeology is important to the study of history because the material remains of the past supplement and interrogate historical documents. Collaboration between cultural anthropologists and archaeologists will produce a broader knowledge of past worlds and how those worlds have been constructed in historical texts, both past and present. Cultural anthropologists and archaeologists should also compare the ways in which they engage in discussions about the past with both the American public and local communities—discussions that are quite different in the two subfields.
Children, Childhoods, and Violence
Authors: Korbin Jill E.
Published: March 2004

▪ Abstract  Anthropological literature on children and violence has been constrained by similar considerations that have limited an anthropology of childhood more generally, and by difficulties in conceptualizing children both as victims of violence and as violent themselves. A review of the anthropological literature on violence directed toward children reveals a litany of violence to which children may be subjected that includes child abuse and neglect, bullying, violent cultural rites, warfare, and structural violence stemming from poverty and inequality. Aggression in childhood has been the subject of a robust and long-standing literature that has examined socialization for or against aggressive behavior in children. An emerging literature considers children's own violent behavior from the perspective of child agency. Children's own voices and perspectives have been largely absent from the anthropological literature on childhood and violence. This review highlights several issues at the intersection of childhood and violence that demand a synthesis and reformulation in anthropology.

“There is a growing consciousness of children at risk … there is also a growing sense of children themselves as the risk …”

     ( Stephens 1995 , p. 13)
Urban Violence and Street Gangs
Authors: Vigil James Diego
Published: March 2004

▪ Abstract  What causes urban street gang violence, and how can we better understand the forces that shape this type of adolescent and youth behavior? For close to a century, social researchers have taken many different paths in attempting to unravel this complex question, especially in the context of large-scale immigrant adaptation to the city. In recent decades these researchers have relied primarily on data gathered from survey quantitative approaches. This review traces some of these developments and outlines how frameworks of analysis have become more integrated and multidimensional, as ethnographic strategies have come into vogue again. For the last couple of decades, either a subculture of violence (i.e., the values and norms of the street gang embrace aggressive, violent behavior) or a routine activities (i.e., hanging around high crime areas with highly delinquent people) explanation dominated the discussion. To broaden and deepen the picture, many other factors need to be considered, such as ecological, socioeconomic, sociocultural, and sociopsychological, particularly in light of the immigrant experience. A multiple marginality framework lends itself to a holistic strategy that examines linkages within the various factors and the actions and interactions among them and notes the cumulative nature of urban street gang violence. Questions that are addressed in this more integrated framework are: Where did they settle? What jobs did they fill? How and why did their social practices and cultural values undergo transformations? When and in what ways did the social environment affect them? Finally, with whom did they interact? In sum, in highlighting the key themes and features of what constitutes urban street gang violence, this review suggests that the qualitative style that relies on holistic information adds important details to traditional quantitative data.
Urbanization and the Global Perspective
Authors: Smart Alan , Smart Josephine
Published: March 2004

▪ Abstract  Much of the literature about globalization exaggerates the degree of novelty. In this review, we concentrate on claims about what has changed about cities under late capitalism and globalization. Although we suggest that cities have long been influenced by global forces, we conclude that the roles of cities in the global system have changed considerably as a result of the time-space compression made possible by new transportation, communication, and organizational technologies. After discussing what the global perspective means within anthropology, and how it affects urban anthropological research, our review concentrates on three complex issues. First is whether the global factory and increasing knowledge-intensivity have decreased or increased the utility of the intermediary or brokerage roles that cities play. Second, we examine changes in how people live in globalizing cities. Third, we consider the implications of the construction and maintenance of relationships across borders for processes of citizenship, affiliation, and transnational social movements.
Highlights and Overview of the History of Educational Ethnography
Authors: Yon Daniel A.
Published: March 2004

▪ Abstract  In broad brush strokes, this essay identifies and reviews key trends and theoretical orientations that have shaped the field of educational ethnography from the period of its inception to the closing decade of the twentieth century. It demonstrates how the growth of educational ethnography as a subfield within anthropology reflects a growing focus on prescriptive, applied, and reformist research within urban contexts. It maps the transition from modernist formulations of the field in its formative days, when ethnographies laid claim to being sealed and scientific texts, to the more recent formulations shaped by postmodern and poststructural ideas that undermine earlier meanings of culture and call attention to the explanatory limits of ethnography. This review draws on examples from North America and Britain and makes no claim to being exhaustive of the vast and growing field. Although it delineates what distinguishes successive decades of educational ethnography, the essay argues for understanding the developments not as distinct phases but as overlapping moments in the evolution of the field of study. Attention is drawn to how developments in theory and method, in particular a move toward reflexivity in educational ethnography, mirror developments in the discipline of anthropology at large.
Intergroup Relations in Chimpanzees
Authors: Wilson Michael L. , Wrangham Richard W.
Published: March 2004

▪ Abstract  In the 1970s, researchers provided the first detailed descriptions of intergroup conflict in chimpanzees. These observations stimulated numerous comparisons between chimpanzee violence and human warfare. Such comparisons have attracted three main objections: (a) The data supporting such comparisons are too few, (b) intergroup aggression is the result of artificial feeding by observers, and (c) chimpanzee data are irrelevant to understanding human warfare. Recent studies provide strong evidence against these criticisms. Data from the five long-term sites with neighboring groups show that intergroup aggression is a pervasive feature of chimpanzee societies, including sites where artificial feeding never took place. Recent studies have clarified questions about the functional goals and proximate mechanisms underlying intergroup aggression. Male chimpanzees compete with males in other groups over territory, food, and females, base their decisions to attack strangers on assessments of numerical strength, and strive for dominance over neighboring groups. Human males likewise compete over territory, food, and females and show a preference for low-risk attacks and intergroup dominance. Chimpanzee studies illustrate the promise of the behavioral biology approach for understanding and addressing the roots of violence in our own species.
MEK/MAPK as a signaling element in ATP control of endothelial myosin light chain
Authors: Klingenberg D. , Gündüz D. , Härtel F. , Bindewald K. , Schäfer M. , Piper H. M. , Noll T.
Published: March 2004

Phosphorylation of endothelial myosin light chains (MLC) is a key mechanism in control of endothelial contractile machinery. Extracellular ATP influences endothelial MLC phosphorylation by either activation of Ca2+-dependent MLC kinase or Ca2+-independent MLC phosphatase. Here, the role of the MEK/MAPK pathway in this signaling was investigated in porcine aortic endothelial cells. Phosphorylation of ERK2 and phosphorylation of MLC were analyzed in cultured aortic endothelial cells. ATP (10 μM) increased ERK2 phosphorylation from basal 17 ± 3 to 53 ± 4%, an effect suppressed in the presence of the MEK inhibitors PD-98059 (20 μM) or U0126 (10 μM). Phosphorylation of ERK2 was not dependent on the ATP-induced cytosolic Ca2+ rise, because it was unaltered when this was suppressed by the Ca2+ chelator BAPTA (10 μM) or xestospongin C (3 μM), an inhibitor of the inositol 1,4,5-trisphosphate-sensitive Ca2+ release mechanism of the endoplasmic reticulum. Phosphorylation of ERK2 was neither induced by the adenosine analog 5′-( N-ethylcarboxamido)adenosine (1 μM) nor inhibited in the presence of the adenosine receptor antagonist 8-phenyltheophylline (10 μM). ATP increased MLC kinase activity, and this was blocked in presence of PD-98059. ATP also increased MLC phosphatase activity, which was not inhibited by PD-98059. The MEK/MAPK pathway is a Ca2+-independent part of ATP signaling toward MLC kinase but not of ATP signaling toward MLC phosphatase.
A voltage-gated K+ current in renal inner medullary collecting duct cells
Authors: Escobar Laura I. , Martínez-Téllez Julio C. , Salas Monica , Castilla Salvador A. , Carrisoza Rolando , Tapia Dagoberto , Vázquez Mario , Bargas José , Bolívar Juan J.
Published: March 2004

We studied the K+-selective conductances in primary cultures of rat renal inner medullary collecting duct (IMCD) using perforated-patch and conventional whole cell techniques. Depolarizations above –20 mV induced a time-dependent outward K+ current ( Ivto) similar to a delayed rectifier. Ivto showed a half-maximal activation around 5.6 mV with a slope factor of 6.8 mV. Its K+/Na+ selectivity ratio was 11.7. It was inhibited by tetraethylammonium, quinidine, 4-aminopyridine, and Ba2+ and was not Ca2+ dependent. The delayed rectifying characteristics of Ivto prompted us to screen the expression of Kv1 and Kv3 families by RT-PCR. Analysis of RNA isolated from cell cultures revealed the presence of three Kv α-subunits (Kv1.1, Kv1.3, and Kv1.6). Western blot analysis with Kv α-subunit antibodies for Kv1.1 and Kv1.3 showed labeling of ∼70-kDa proteins from inner medulla plasmatic and microsome membranes. Immunocytochemical analysis of cell culture and kidney inner medulla showed that Kv1.3 is colocalized with the Na+-K+-ATPase at the basolateral membrane, although it is also in the cytoplasm. This is the first evidence of recording, protein expression, and localization of a voltage-gated Kv1 in the kidney IMCD cells.
Rat cerebellar granule cells are protected from glutamate-induced excitotoxicity by S-nitrosoglutathione but not glutathione
Authors: Li Chung-Yu , Chin Ting-Yu , Chueh Sheau-Huei
Published: March 2004

In cultured rat cerebellar granule cells, glutamate or N-methyl-d-aspartate (NMDA) activation of the NMDA receptor caused a sustained increase in cytosolic Ca2+ levels ([Ca2+]i), reactive oxygen species (ROS) generation, and cell death (respective EC50 values for glutamate were 12, 30, and 38 μM) but no increase in caspase-3 activity. Removal of extracellular Ca2+ blocked all three glutamate-induced effects, whereas pretreatment with an ROS scavenger inhibited glutamate-induced cell death but had no effect on the [Ca2+]i increase. This indicates that glutamate-induced cell death is attributable to [Ca2+]i increase and ROS generation, and the [Ca2+]i increase precedes ROS generation. Apoptotic cell death was not seen until 24 h after exposure of cells to glutamate. S-nitrosoglutathione abolished glutamate-induced ROS generation and cell death, and only a transient [Ca2+]i increase was seen; similar results were observed with another nitric oxide (NO) donor, S-nitroso- N-acetylpenicillamine, but not with glutathione, which suggests that the effects were caused by NO. The transient [Ca2+]i increase and the abolishment of ROS generation induced by glutamate and S-nitrosoglutathione were still seen in the presence of an ROS scavenger. Glial cells, which were present in the cultures used, showed no [Ca2+]i increase in the presence of glutamate, and glutamate-induced granule cell death was independent of the percentage of glial cells. In conclusion, NO donors protect cultured cerebellar granule cells from glutamate-induced cell death, which is mediated by ROS generated by a sustained [Ca2+]i increase, and glial cells provide negligible protection against glutamate-induced excitotoxicity.
Plasma membrane aquaporin activity can affect the rate of apoptosis but is inhibited after apoptotic volume decrease
Authors: Jablonski Elizabeth M. , Webb Ashley N. , McConnell Nisha A. , Riley Marcus C. , Hughes Francis M.
Published: March 2004

Apoptosis is characterized by a conserved series of morphological events beginning with the apoptotic volume decrease (AVD). This study investigated a role for aquaporins (AQPs) during the AVD. Inhibition of AQPs blocked the AVD in ovarian granulosa cells undergoing growth factor withdrawal and blocked downstream apoptotic events such as cell shrinkage, changes in the mitochondrial membrane potential, DNA degradation, and caspase-3 activation. The effects of AQP inhibition on the AVD and DNA degradation were consistent in thymocytes and with two additional apoptotic signals, thapsigargin and C6-ceramide. Overexpression of AQP-1 in Chinese hamster ovary (CHO-AQP-1) cells enhanced their rate of apoptosis. The AVD is driven by loss of K+ from the cell, and we hypothesize that after the AVD, AQPs become inactive, which halts further water loss and allows K+ concentrations to decrease to levels necessary for apoptotic enzyme activation. Swelling assays on granulosa cells, thymocytes, and CHO-AQP-1 cells revealed that indeed, the shrunken (apoptotic) subpopulation has very low water permeability compared with the normal-sized (nonapoptotic) subpopulation. In thymocytes, AQP-1 is present and was shown to colocalize with the plasma membrane receptor tumor necrosis factor receptor-1 (TNF-R1) both before and after the AVD, which suggests that this protein is not proteolytically cleaved and remains on the cell membrane. Overall, these data indicate that AQP-mediated water loss is important for the AVD and downstream apoptotic events, that the water permeability of the plasma membrane can control the rate of apoptosis, and that inactivation after the AVD may help create the low K+ concentration that is essential in apoptotic cells. Furthermore, inactivation of AQPs after the AVD does not appear to be through degradation or removal from the cell membrane.
Compensatory responses of protein import and transcription factor expression in mitochondrial DNA defects
Authors: Joseph Anna-Maria , Rungi Arne A. , Robinson Brian H. , Hood David A.
Published: March 2004

Defects in mitochondrial DNA (mtDNA) evoke distinctive responses in the nuclear genome, leading to altered mitochondrial biogenesis. We used C2C12 cells depleted of mtDNA (rho– cells) and fibroblasts from a mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS) patient to examine adaptations of the protein import machinery and transcription factors involved in mitochondrial biogenesis. In rho– cells, Tom20 and Tim23 protein levels were reduced by 25% and 59%, whereas mtHSP70 was induced by twofold relative to control cells. These changes were accompanied by a 21% increase in enhanced yellow fluorescent protein (EYFP) import into mitochondria in rho– cells ( P < 0.05). In contrast, in MELAS cells mtHSP70 was elevated by 70%, whereas Tom20 and Tom34 protein levels were increased by 45% and 112% relative to control values. EYFP import was not altered in MELAS cells. In rho– cells, protein levels of the transcription factors nuclear respiratory factor-1 (NRF-1) and transcription factor A (Tfam) declined by 33% and 54%, whereas no change was observed for the coactivator peroxisome proliferator receptor-γ coactivator-1α (PGC-1α). In contrast, Tfam was increased by 40% in MELAS cells. Rho– cells displayed reduced oxygen consumption (V̇o2) and ATP levels, along with a twofold increase in lactate levels ( P < 0.05). In electrically stimulated C2C12 cells, 109%, 78%, 60%, and 67% increases were observed in mtDNA, V̇o2, cytochrome- c oxidase (COX) activity, and Tom34 levels, respectively ( P < 0.05). Our findings suggest that compensatory adaptations occurred to maintain normal rates of protein import in response to mtDNA defects and support a role for contractile activity in reducing pathophysiology associated with mtDNA depletion. Because the expression of nuclear-encoded transcription factors and protein import machinery components was dependent on the type of mtDNA defect, these findings suggest involvement of distinct signaling cascades, each dependent on the type of mitochondrial defect, resulting in divergent changes in nuclear gene expression patterns.