bluuebunny/crossref_metadata_2025 huggingface dataset:
Peak Bone Mass After Exposure to Antenatal Betamethasone and Prematurity: Follow-up of a Randomized Controlled Trial
Authors: Dalziel Stuart R , Fenwick Sheryl , Cundy Tim , Parag Varsha , Beck Thomas J , Rodgers Anthony , Harding Jane E
Published: July 2006

Small birth size is associated with reduced adult bone mass. We determined if antenatal betamethasone exposure, birth weight, or prematurity affects peak bone mass in 174 adults. Antenatal betamethasone exposure did not. Lower birth weight and prematurity predicted reduced adult height. Slower fetal growth rather than prematurity predicted lower bone mass, but this lower bone mass was appropriate for reduced adult height.

Introduction: Small size at birth is reported to be associated with lower bone mass in adulthood. However, previous studies have not distinguished the relative contributions of length of gestation and fetal growth to size at birth. Fetal exposure to excess glucocorticoids has been proposed as a core mechanism underlying the associations between birth size and later disease risk. Antenatal glucocorticoids are given to pregnant women at risk for preterm delivery for the prevention of neonatal respiratory distress syndrome in their infants. We determined the relationship of antenatal exposure to betamethasone, birth weight, and prematurity to peak bone mass and femoral geometry in the adult survivors of the first randomized trial of antenatal glucocorticoids.

Materials and Methods: We studied 174 young adults (mean age, 31 years) whose mothers participated in a randomized trial of antenatal betamethasone. Mothers received two doses of intramuscular betamethasone or placebo 24 h apart. Two thirds of participants were born preterm (<37 weeks gestation). We measured indices of bone mass and size and derived estimates of volumetric density and bone geometry from DXA assessments of the lumbar spine, femur, and total body.

Results: There were no differences between betamethasone-exposed and placebo-exposed groups in any of the lumbar spine, femur, or total body DXA measures. There was no effect of antenatal betamethasone on adult height, although leg length was increased relative to trunk length (p = 0.002). A lighter birth weight (p ≤ 0.001) and lower gestational age (p = 0.013) were associated with shorter stature (height Z scores) at age 31 years. Prematurity had no effect on peak bone mass or femoral geometry. However, lower birth weight, independent of gestational age, was associated with lower later bone mass (p < 0.001 for lumbar spine and total body, p = 0.003 for femoral neck BMC). These effects on bone mass were related to bone size and not to estimates of volumetric density. In the femur, lower birth weight, independent of gestational age, was associated with narrowing of the upper shaft and narrow neck regions.

Conclusions: Antenatal betamethasone exposure does not affect peak bone mass or femoral geometry in adulthood. Birth weight and prematurity predict adult height, but it is slower fetal growth, rather than prematurity, that predicts lower peak bone mass. The lower peak bone mass in those born small is appropriate for their adult height.
Wide-Field Retinotopy Defines Human Cortical Visual Area V6
Authors: Pitzalis Sabrina , Galletti Claudio , Huang Ruey-Song , Patria Fabiana , Committeri Giorgia , Galati Gaspare , Fattori Patrizia , Sereno Martin I.
Published: July 2006

The retinotopic organization of a newly identified visual area near the midline in the dorsalmost part of the human parieto-occipital sulcus was mapped using high-field functional magnetic resonance imaging, cortical surface-based analysis, and wide-field retinotopic stimulation. This area was found in all 34 subjects that were mapped. It represents the contralateral visual hemifield in both hemispheres of all subjects, with upper fields located anterior and medial to areas V2/V3, and lower fields medial and slightly anterior to areas V3/V3A. It contains a representation of the center of gaze distinct from V3A, a large representation of the visual periphery, and a mirror-image representation of the visual field. Based on similarity in position, visuotopic organization, and relationship with the neighboring extrastriate visual areas, we suggest it might be the human homolog of macaque area V6, and perhaps of area M (medial) or DM (dorsomedial) of New World primates.
Stress-Induced Alterations in Prefrontal Cortical Dendritic Morphology Predict Selective Impairments in Perceptual Attentional Set-Shifting
Authors: Liston Conor , Miller Melinda M. , Goldwater Deena S. , Radley Jason J. , Rocher Anne B. , Hof Patrick R. , Morrison John H. , McEwen Bruce S.
Published: July 2006

Stressful life events have been implicated clinically in the pathogenesis of mental illness, but the neural substrates that may account for this observation remain poorly understood. Attentional impairments symptomatic of these psychiatric conditions are associated with structural and functional abnormalities in a network of prefrontal cortical structures. Here, we examine whether chronic stress-induced dendritic alterations in the medial prefrontal cortex (mPFC) and orbital frontal cortex (OFC) underlie impairments in the behaviors that they subserve. After 21 d of repeated restraint stress, rats were tested on a perceptual attentional set-shifting task, which yields dissociable measures of reversal learning and attentional set-shifting, functions that are mediated by the OFC and mPFC, respectively. Intracellular iontophoretic injections of Lucifer yellow were performed in a subset of these rats to examine dendritic morphology in layer II/III pyramidal cells of the mPFC and lateral OFC. Chronic stress induced a selective impairment in attentional set-shifting and a corresponding retraction (20%) of apical dendritic arbors in the mPFC. In stressed rats, but not in controls, decreased dendritic arborization in the mPFC predicted impaired attentional set-shifting performance. In contrast, stress was not found to adversely affect reversal learning or dendritic morphology in the lateral OFC. Instead, apical dendritic arborization in the OFC was increased by 43%. This study provides the first direct evidence that dendritic remodeling in the prefrontal cortex may underlie the functional deficits in attentional control that are symptomatic of stress-related mental illnesses.
Mapping Implied Body Actions in the Human Motor System
Authors: Urgesi Cosimo , Moro Valentina , Candidi Matteo , Aglioti Salvatore M.
Published: July 2006

The human visual system is highly tuned to perceive actual motion as well as to extrapolate dynamic information from static pictures of objects or creatures captured in the middle of motion. Processing of implied motion activates higher-order visual areas that are also involved in processing biological motion. Imagery and observation of actual movements performed by others engenders selective activation of motor and premotor areas that are part of a mirror-neuron system matching action observation and execution. By using single-pulse transcranial magnetic stimulation, we found that the mere observation of static snapshots of hands suggesting a pincer grip action induced an increase in corticospinal excitability as compared with observation of resting, relaxed hands, or hands suggesting a completed action. This facilitatory effect was specific for the muscle that would be activated during actual execution of the observed action. We found no changes in responsiveness of the tested muscles during observation of nonbiological entities with (e.g., waterfalls) or without (e.g., icefalls) implied motion. Thus, extrapolation of motion information concerning human actions induced a selective activation of the motor system. This indicates that overlapping motor regions are engaged in the visual analysis of physical and implied body actions. The absence of motor evoked potential modulation during observation of end posture stimuli may indicate that the observation–execution matching system is preferentially activated by implied, ongoing but not yet completed actions.
Neural Stem Cells RescuenervousPurkinje Neurons by Restoring Molecular Homeostasis of Tissue Plasminogen Activator and Downstream Targets
Authors: Li Jianxue , Imitola Jaime , Snyder Evan Y. , Sidman Richard L.
Published: July 2006

Neural stem cells (NSCs) offer special therapeutic prospects because they can be isolated from the CNS, expandedex vivo, and re-implanted into diseased CNS where they not only migrate and differentiate according to cues from host tissue but also appear to be capable of affecting host cells. Innervous(nr) mutant mice Purkinje neuron (PN) mitochondria become abnormal by the second postnatal week, and a majority of PNs die in the fourth to fifth weeks. We previously identified innrcerebellum a 10-fold increase in tissue plasminogen activator (tPA) as a key component of the mechanism causingnrPN death. Here we report that undifferentiated wild-type murine NSCs, when transplanted into the newbornnrcerebellar cortex, do not replace host PNs but contact imperiled PNs and support their mitochondrial function, dendritic growth, and synaptogenesis, subsequently leading to the rescue of host PNs and restoration of motor coordination. This protection ofnrPNs also is verified by anin vitroorganotypic slice model in whichnrcerebellar slices are cocultured with NSCs. Most importantly, the integrated NSCs in youngnrcerebellum rectify excessive tPA mRNA and protein to close to normal levels and protect the mitochondrial voltage-dependent anion channel and neurotrophins, downstream targets of the tPA/plasmin proteolytic system. This report demonstrates for the first time that NSCs can rescue imperiled host neurons by rectifying their gene expression, elevating somatic stem cell therapeutic potential beyond solely cell replacement strategy.
Regulation of Secretory Protein Expression in Mature Cells by DIMM, a Basic Helix–Loop–Helix Neuroendocrine Differentiation Factor
Authors: Hewes Randall S. , Gu Tingting , Brewster Jordan A. , Qu Chunjing , Zhao Tao
Published: July 2006

During differentiation, neuroendocrine cells acquire highly amplified capacities to synthesize neuropeptides to overcome dilution of these signals in the general circulation. Once mature, the normal functioning of integrated physiological systems requires that neuroendocrine cells remain plastic to dramatically alter neuropeptide expression for long periods in response to hormonal and electrical cues. The mechanisms underlying the long-term regulation of neuroendocrine systems are poorly understood. Here we show that theDrosophilabasic helix-loop-helix protein DIMM, a critical regulator of neuroendocrine cell differentiation, controls secretory capacity in mature neurons. DIMM expression began embryonically but persisted in adults. Through spatial and temporal manipulation of transgene expressionin vivo, we defined two phases of prosecretory DIMM activity. During an embryonic critical window, DIMM controlled the differentiation of amplified expression of the neuropeptide leucokinin. At the onset of metamorphosis, levels of DIMM decreased in the insulin-producing cells (IPCs) in parallel with a marked reduction in levels ofDrosophilainsulin-like peptide 2 and a key neuropeptide biosynthetic enzyme peptidylglycine α-monooxygenase (PHM). Overexpression of DIMM in the IPCs prevented the decrease in PHM levels at this stage. In addition, transient overexpression of DIMM in adults produced a dramatic increase in PHM levels in numerous neurons located throughout the brain. These findings provide insights into the mechanisms controlling the maintenance of differentiated cell states, and they suggest an effective means for dynamically adjusting the strength of hormonal signals in diverse homeostatic systems.
Two Psychophysical Channels of Whisker Deflection in Rats Align with Two Neuronal Classes of Primary Afferents
Authors: Stüttgen Maik C. , Rüter Johannes , Schwarz Cornelius
Published: July 2006

The rat whisker system has evolved into in an excellent model system for sensory processing from the periphery to cortical stages. However, to elucidate how sensory processing finally relates to percepts, methods to assess psychophysical performance pertaining to precise stimulus kinematics are needed. Here, we present a head-fixed, behaving rat preparation that allowed us to measure detectability of a single whisker deflection as a function of amplitude and peak velocity. We found that velocity thresholds for detection of small-amplitude stimuli (<3°) were considerably higher than for detection of large-amplitude stimuli (>3°). This finding suggests the existence of two psychophysical channels mediating detection of whisker deflection: one channel exhibiting high amplitude and low velocity thresholds (W1), and the other channel exhibiting high velocity and low amplitude thresholds (W2). The correspondence of W1 to slowly adapting (SA) and W2 to rapidly adapting (RA) neuronal classes in the trigeminal ganglion was revealed in acute neurophysiological experiments. Neurometric plots of SA and RA cells were closely aligned to psychophysical performance in the corresponding W1 and W2 parameter ranges. Interestingly, neurometric data of SA cells fit the behavior best if it was based on a short time window integrating action potentials during the initial phasic response, in contrast to integrating across the tonic portion of the response. This suggests that detection performance in both channels is based on the assessment of very few spikes in their corresponding groups of primary afferents.
Retraction of Synapses and Dendritic Spines Induced by Off-Target Effects of RNA Interference
Authors: Alvarez Veronica A. , Ridenour Dennis A. , Sabatini Bernardo L.
Published: July 2006

RNA interference (RNAi), which allows selective gene silencing, has been proposed for functional genomic analysis and for the treatment of human disease. However, induction of RNAi in mammalian cells by expression of double-stranded RNA can activate innate antiviral response pathways that perturb off-target gene expression. The activation and functional consequences of these effects in neurons are unknown. We find that expression of subsets of short hairpin RNAs (shRNAs) in rat hippocampal pyramidal neurons can have off-target effects that reduce the complexity of dendritic arbors and trigger the loss of dendritic spines. Morphological changes are accompanied by electrophysiological perturbations in passive membrane properties and a decrease in the number and strength of excitatory and inhibitory synapses. These perturbations depend on the shRNA sequence and are independent of the identity of the targeted protein. Our results indicate that off-target effects of RNAi severely perturb neuronal structure and function and may lead to the functional withdrawal of affected cells from the brain circuitry.
Local Field Potential in Cortical Area MT: Stimulus Tuning and Behavioral Correlations
Authors: Liu Jing , Newsome William T.
Published: July 2006

Low-frequency electrical signals like those that compose the local field potential (LFP) can be detected at substantial distances from their point of origin within the brain. It is thus unclear how useful the LFP might be for assessing local function, for example, on the spatial scale of cortical columns. We addressed this problem by comparing speed and direction tuning of LFPs obtained from middle temporal area MT with the tuning of multiunit (MU) activity recorded simultaneously. We found that the LFP can be well tuned for speed and direction and is highly correlated with that of MU activity, particularly for frequencies at and above the gamma band. LFP tuning is substantially poorer for lower frequencies, although tuning for direction extends to lower frequencies than does tuning for speed. Our data suggest that LFP signals at and above the gamma band reflect neural processing on the spatial scale of cortical columns, within a few hundred micrometers of the electrode tip. Consistent with this notion, we also found that frequencies at and above the gamma band measured during a speed discrimination task exhibit an effect known as “choice probability,” which reveals a particularly close relationship between neural activity and behavioral choices. In the LFP, this signature of the perceptual choice comprises a shift in relative power from low-frequency bands (α and β) to the gamma band. It remains to be determined how LFP choice probability, which is a temporal signature, is related to conventional choice probability effects observed in spike rates.
Bridging the Divide: Drinking among Street Drug Users
Authors: SINGER MERRILL , SALAHEEN HASSAN , MIRHEJ GREG , SANTELICE CLAUDIA
Published: July 2006

In this research report, we present findings on drinking among drug users from a larger multimethod study of the public health consequences of emergent, changing, and understudied drug‐related behavioral patterns among street drug users in Hartford, CT. Although drinking and illicit drug use traditionally have been studied in anthropology as separate cultural domains, this conceptual division has hindered examination of the significant level of drinking among street drug users, the motivations for heavy drinking in this population, and the public health consequences of mixing alcohol and other drugs, including drug relapse.
Timothy Asch and Ethnographic Film
Authors: PEDERSEN LENE
Published: July 2006

Timothy Asch and Ethnographic Film. E. D. Lewis, ed. London: Routledge Harwood Anthropology, 2004. 297 pp.
Stones through the Window
Authors: KALB DON
Published: July 2006

Civilizing Globalization: A Survival Guide. Richard Sandbrook, ed. Albany: State University of New York Press, 2003. 279 pp.

Globalization, the State, and Violence. Jonathan Friedman, ed. Walnut Creek, CA: AltaMira Press, 2003. 389 pp.
Looking for Identity in the Muslim World
Authors: SHIVELY KIM
Published: July 2006

Dramas of Nationhood: The Politics of Television in Egypt. Lila Abu‐Lughod. Chicago: University Chicago Press, 2005. 319 pp.

Memories of State: Politics, History, and Collective Identity in Modern Iraq. Eric Davis. Berkeley: University of California Press, 2005. 385 pp.

Religion, Social Practice, and Contested Hegemonies: Reconstructing the Public Sphere in Muslim Majority Societies. Armando Salvatore and Mark LeVine, eds. New York: Palgrave Macmillan, 2005. 249 pp.

Contesting Rituals: Islam and Practices of Identity Making. Pamela Stewart and Andrew Strathern, eds. Durham, NC: Carolina Academic Press, 2005. 239 pp.
The Archaeology of the Colonized; An Archaeology of Colonial Identity: Power and Material Culture in the Dwars Valley, South Africa
Authors: LaVIOLETTE ADRIA
Published: July 2006

The Archaeology of the Colonized. Michael Given. New York: Routledge, 2004. 187 pp.

An Archaeology of Colonial Identity: Power and Material Culture in the Dwars Valley, South Africa. Gavin Lucas. New York: Kluwer Academic/Plenum Press, 2004. 223 pp.
Urban Place: Reconnecting with the Natural World
Authors: GORDON ANDREW J.
Published: July 2006

Urban Place: Reconnecting with the Natural World. Peggy F. Barlett, ed. Cambridge, MA: MIT Press, 2005. 330 pp.
Bodies of Evidence: Burial, Memory and the Recovery of Missing Persons in Cyprus
Authors: ROSS ANN
Published: July 2006

Bodies of Evidence: Burial, Memory and the Recovery of Missing Persons in Cyprus. Paul Sant Cassia. New York: Berghahn Books, 2005. 246 pp.
Powwow
Authors: KRACHT BENJAMIN R.
Published: July 2006

Powwow. Clyde Ellis, Luke Eric Lassiter, and Gary H. Dunham, eds. Lincoln: University of Nebraska Press, 2005. 309 pp.
Notes from the Balkans: Locating Marginality and Ambiguity on the Greek‐Albanian Border
Authors: KARAKASIDOU ANASTASIA
Published: July 2006

Notes from the Balkans: Locating Marginality and Ambiguity on the Greek‐Albanian Border. Sarah F. Green. Princeton: Princeton University Press, 2005. 320 pp.
Waiting for Wolves in Japan: An Anthropological Study of People–Wildlife Relations
Authors: HART DONNA
Published: July 2006

Waiting for Wolves in Japan: An Anthropological Study of People–Wildlife Relations. John Knight. New York: Oxford University Press, 2005. 296 pp.
Shouldering Risks: The Culture of Control in the Nuclear Power Industry
Authors: SKIPPER WILLIAM
Published: July 2006

Shouldering Risks: The Culture of Control in the Nuclear Power Industry. Constance Perin. Princeton: Princeton University Press, 2005. 379 pp.
Algeria in France: Transpolitics, Race, and Nation
Authors: GOODMAN JANE E.
Published: July 2006

Algeria in France: Transpolitics, Race, and Nation. Paul A. Silverstein. Indianapolis: Indiana University Press, 2004. 284 pp.
Defining Women's Health: A Dozen Messages from More than 150 Ethnographies
Authors: Inhorn Marcia C.
Published: July 2006

Although the women's health research agenda has been largely defined by Western biomedicine and public health, anthropology has much to offer in terms of defining and understanding women's health from the perspective of women themselves. Through the in‐depth qualitative tradition of ethnography, anthropologists have documented women's health concerns around the globe, producing a large and constantly expanding literature that is rich and provocative. This article summarizes a dozen major messages about women's health that emerge from the ethnographic literature, now consisting of more than 150 volumes. These volumes are listed in the article, and some primary examples are described as representative of anthropology's contribution to knowledge production in women's health.
User subjectivity in Monte Carlo modeling of pesticide exposure
Authors: Beulke Sabine , Brown Colin D. , Dubus Igor G. , Galicia Hector , Jarvis Nicholas , Schaefer Dieter , Trevisan Marco
Published: July 2006

Monte Carlo techniques are increasingly used in pesticide exposure modeling to evaluate the uncertainty in predictions arising from uncertainty in input parameters and to estimate the confidence that should be assigned to the modeling results. The approach typically involves running a deterministic model repeatedly for a large number of input values sampled from statistical distributions. In the present study, six modelers made choices regarding the type and parameterization of distributions assigned to degradation and sorption data for an example pesticide, the correlation between the parameters, the tool and method used for sampling, and the number of samples generated. A leaching assessment was carried out using a single model and scenario and all data for sorption and degradation generated by the six modelers. The distributions of sampled parameters differed between the modelers, and the agreement with the measured data was variable. Large differences were found between the upper percentiles of simulated concentrations in leachate. The probability of exceeding 0.1 μg/L ranged from 0 to 35.7%. The present study demonstrated that subjective choices made in Monte Carlo modeling introduce variability into probabilistic modeling and that the results need to be interpreted with care.
Ecotoxicity of mixtures of antibiotics used in aquacultures
Authors: Christensen Anne Munch , Ingerslev Flemming , Baun Anders
Published: July 2006

More or less well-defined mixtures of antibiotics used in aquacultures may be distributed in the aquatic environment. Therefore, a systematic mixture ecotoxicity study was performed with the aquaculture antibiotics oxytetracycline, oxolinic acid, erythromycin, florfenicol, and flumequine. Test organisms were freshwater algae (Pseudokirchneriella subcapitata), activated sludge microorganisms, and luminescent bacteria (Vibrio fischeri). Design and statistical analysis of test results were based on isobolographic analysis. Synergistic effects were observed when combinations of erythromycin and oxytetracycline were tested on activated sludge microorganisms, and in these cases model predictions indicate independent action on the different bacterial species in the sludge. As predicted from the modes of action, concentration addition was evident when flumequine and oxolinic acid were mixed and tested on sludge bacteria. In the algae test, the combined toxicity of antibiotics could not be predicted based on knowledge of the modes of action of the individual compounds. Independent of the test species, our results gave examples of combined effects that were higher than predicted based on the assumption of concentration addition. This result underlines the need to consider the effects of mixtures of antibiotics on environmental organisms. The isobolographic method appears to be a suitable tool for this purpose, particularly for well-defined mixtures with few substances.
A novel contact assay for testing genotoxicity of chemicals and whole sediments in zebrafish embryos
Authors: Kosmehl Thomas , Hallare Arnold V. , Reifferscheid Georg , Manz Werner , Braunbeck Thomas , Hollert Henner
Published: July 2006

Broad consensus exists that whole-sediment exposure protocols represent the most realistic scenario to simulate in situ exposure conditions. So far, however, several endpoints including genotoxicity in vertebrate-based systems could be tested only after transfer of particle-bound substances into the aqueous phase. The present study was carried out to develop a protocol for generating a suspension of single cells from sediment-exposed zebrafish embryos that is suitable for detecting particle-bound genotoxicity in the alkaline single cell gel electrophoresis (comet assay). In this solid-phase genotoxicity assay, a whole-body cell suspension derived from zebrafish embryos exposed to native (whole) sediments is assayed in the comet assay. Several chemical and mechanical isolation procedures were compared to optimize cell yield and minimize DNA damage by the method itself. If compared to collagenase isolation, mechanical cell dissociation gave less DNA damage; trypsinization resulted in similarly low DNA damage but significantly lower cell yield. In order to test the optimized protocol, effects of well-known genotoxicants (4-nitroquinoline-N-oxide, nitrofurantoin, hydrogen peroxide, benzo[a]pyrene) and of two sediments from the upper Rhine River (Germany) on zebrafish embryos were investigated. Results documented clear-cut genotoxicity for all four substances and for one of the two whole-sediment samples. An ultraviolet (UV) light exposure of whole embryos and primary cultures from embryos elucidated only minor effects for the whole embryos compared to the primary cells. Consequently, UV irradiation cannot be suggested as a positive control in intact zebrafish embryos. In conclusion, the newly developed sediment contact assay can be recommended for the detection of both single substances but also the bioavailable fraction of the total hazard potential of sediments.
A Geographic Information Systems–based, weights-of-evidence approach for diagnosing aquatic ecosystem impairment
Authors: Kapo Katherine E. , Burton G. Allen
Published: July 2006

A Geographic Information Systems–based, watershed-level assessment using Bayesian weights of evidence (WOE) and weighted logistic regression (WLR) provides a method to determine and compare potential environmental stressors in lotic ecosystems and to create predictive models of general or species-specific biological impairment across numerous spatial scales based on limited existing sample data. The WOE/WLR technique used in the present study is a data-driven, probabilistic approach conceptualized in epidemiological research and both developed for and currently used in minerals exploration. Extrapolation of this methodology to a case-study watershed assessment of the Great and Little Miami watersheds (OH, USA) using archival data yielded baseline results consistent with previous assessments. The method additionally produced a quantitative determination of physical and chemical watershed stressor associations with biological impairment and a predicted comparative probability (i.e., favorability) of biological impairment at a spatial resolution of 0.5 km2 over the watershed study region. Habitat stressors showed the greatest spatial association with biological impairment in low-order streams (on average, 56% of total spatial association), whereas water chemistry, particularly that of wastewater effluent, was associated most strongly with biological impairment in high-order reaches (on average, 79% of total spatial association, 28% of which was attributed to effluent). Significant potential stressors varied by land-use and stream order as well as by species. This WOE/WLR method provides a highly useful “tier 1” watershed risk assessment product through the integration of various existing data sources, and it produces a clear visual communication of areas favorable for biological impairment and a quantitative ranking of candidate stressors and associated uncertainty.
Interaction of planar and nonplanar organic contaminants with coal fly ash: Effects of polar and nonpolar solvent solutions
Authors: Burgess Robert M. , Ryba Stephan A. , Cantwell Mark G. , Gundersen Jennifer L. , Tien Rex , Perron Monique M.
Published: July 2006

Coal fly ash has a very high sorption capacity for a variety of anthropogenic contaminants and has been used to cleanse wastewater of pollutants for approximately 40 years. Like other black carbons, the planar structure of the residual carbon in fly ash results in elevated affinities for planar organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and some polychlorinated biphenyls (PCBs). The present study was performed to understand better the mechanisms affecting the strong interaction between planar contaminants and coal fly ash. The removal of 10 PCBs and 10 PAHs by several fly ashes and other sorbents was evaluated under different experimental conditions to highlight the intermolecular forces influencing adsorption. Varying fly ash concentration and solvent system composition indicated that dispersive interactions were most prevalent. For the PCBs, empirical results also were compared to molecular modeling estimates of the energy necessary for the PCB molecule to assume a planar conformation (PCe). The PCe levels ranged from 8 to 25 kcal/mol, depending on the degree of ortho-substituted chlorination of the PCB. A significant correlation between PCe and PCB removal from solution was observed for the fly ashes and activated carbon, whereas the nonplanar sorbent octadecyl (C18) indicated no relationship. These findings demonstrate the strong interaction between black carbon fly ash and planar organic contaminants. Furthermore, as exemplified by the PCBs, these results show how this interaction is a function of a contaminant's ability to assume a planar conformation.
Degradation kinetics of glucosinolates in soil
Authors: Gimsing Anne Louise , Sørensen Jens Christian , Tovgaard Line , Jørgensen Anne Marie Friis , Hansen Hans Christian Bruun
Published: July 2006

Glucosinolates are compounds produced by all cruciferous plants. They can be hydrolyzed to several biologically active compounds and, as such, may serve as naturally produced pesticides. To optimize the pesticidal (biofumigation) effect and to assess the risk of glucosinolate leaching and spread in the environment, the degradation in soil of glucosinolates has been studied. The kinetics of degradation of four glucosinolates, two aliphatic (but-3-enyl and 2-hydroxy-but-3-enyl) and two aromatic (benzyl and phenethyl), in four soils was largely independent of the specific glucosinolate structure. Degradation followed logistic kinetics. Degradation was much faster in a clayey soil (half-life, 3.5–6.8 h) than in a sandy soil (half-life, 9.2–15.5 h). Degradation was much slower or nonexistent in the subsoil (<25 cm soil depth). The glucosinolates are not sorbed in the soil, and the degradation potential is, to a large extent, associated with the clay fraction. Measured activity in the soils of the enzyme myrosinase, which can catalyze the hydrolysis of glucosinolates, correlated well with the glucosinolate degradation kinetics. Autoclaving, but not sodium azide or γ-irradiation, effectively blocked glucosinolate degradation, indicating that extracellular myrosinase is important for glucosinolate degradation.
Persistence and movement of fipronil termiticide with under-slab and trenching treatments
Authors: Ying Guang-Guo , Kookana Rai S.
Published: July 2006

To have an effective barrier against invading termites around building structures and to assess the potential risks to the urban environment and human beings, we need to understand the fate of termiticides applied in urban soil. The movement and degradation of a new termiticide, fipronil, were investigated in Australian soils following standard termiticide treatment methods (surface application under slab and trenching treatments along walls). Surface application studies in three field sites showed slow dissipation and little movement for fipronil in all three soils under the simulated slab during a three-year period. The greatest mass of the chemical residues remained in the quartzite sand layer (thickness, 5 cm), and only small amounts of these were found to have migrated into the soil layers (depth, 0–15 cm) underneath the quartzite sand layer. Of the three metabolites (desulfinyl, sulfide, and sulfone) found in the soils, the sulfone derivative had the highest concentration. Persistence of fipronil was affected by application rate. The time for 50% loss of the total toxic components (fipronil plus its metabolites) in the quartzite sand layer (thickness, 5 cm) ranged from 200 to 326 d for the low rate (0.15 g active ingredient/m2) and from 633 to 674 d for the high application rate (3 g active ingredient/m2). One-year trenching studies at two sites in Adelaide (Roseworthy Farm [RF] and Terretfield [TF]; South Australia, Australia) showed that vertical movement and dissipation of fipronil occurred in the soils. The average concentration of fipronil in the trenches (depth, 0–30 cm) decreased from 33.7 to 14.9 mg/kg in the loam soil at the RF site and from 39.4 to 14.6 mg/kg in the clay soil at the TF site over the year. With time under the natural weather condition, fipronil and its derivatives were found in the deeper soil sections without treatment (depth, 20–30 cm). However, laboratory studies using repacked soil columns showed low mobility in the loam soil from the RF site and a variably charged clay soil from Malanda (Queensland, Australia) under intermittent wetting and drying conditions.
Response of a Leafy and Non‐Leafy Maize Hybrid to Population Densities and Fertilizer Nitrogen Levels
Authors: Subedi K. D. , Ma B. L. , Smith D. L.
Published: July 2006

Optimum plant population density (PPD) of maize (Zea mays L.) for grain and/or silage production depends on hybrid type, soil fertility and agronomic management. Limited information exists on the yield response of Leafy maize hybrids to different PPD under varying N application rates. A field study was conducted during 2003 and 2004 in Ottawa, Canada to evaluate grain and silage yields of a Leafy hybrid (‘Maizex LF850 RR’) with a conventional hybrid (‘Pioneer 3893’), under three PPD (60 000, 75 000, and 90 000 plants ha−1) and four N fertilizer (0, 75, 150, and 225 kg N ha−1) regimes. Canopy light interception, plant dry matter (DM), silage, and grain yield were measured. The Leafy hybrid had 20 to 25% more leaf area, on an individual plant basis, and produced significantly greater silage DM (21.1 vs. 20.0 Mg ha−1), but had a significantly smaller grain yield (9.4 Mg ha−1) than the conventional hybrid (9.7 Mg ha−1). The Leafy hybrid was more sensitive to high density and low N stresses, resulting in more barren plants (up to 15%), lower harvest index (HI), thus significantly lower grain yield than the conventional hybrid in 2003. Grain yield reached to a maximum with 225 kg N ha−1 followed by 75 and 150 kg N ha−1, but silage DM was not different between 150 and 225 kg N ha−1 Plant population density had no effect on grain yield but silage yield increased linearly as PPD increased from 60 000 to 90 000 plants ha−1 Within the tested range of PPD, no differential response of hybrids was observed in terms of grain yield or silage DM, and N treatments had no effect on response of hybrids to PPD. We conclude that the Leafy hybrid was more sensitive to high PPD and low N stresses than the conventional hybrid especially for grain production. The optimum PPD for silage production may be beyond 90 000 plants ha−1 for both types of hybrids.
Using Orchardgrass and Endophyte‐Free Fescue Versus Endophyte‐Infected Fescue Overseeded on Bermudagrass for Cow Herds: I. Four‐Year Summary of Forage Characteristics
Authors: Coblentz W. K. , Coffey K. P. , Smith T. F. , Hubbell D. S. , Scarbrough D. A. , Humphry J. B. , McGinley B. C. , Turner J. E. , Jennings J. A. , West C. P. , Popp M. P. , Hellwig D. H. , Kreider D. L. , Rosenkrans C. F.
Published: July 2006

A systems trial was designed to evaluate forage characteristics within mixed‐species pastures consisting of (i) endophyte‐infected tall fescue (Festuca arundinacea Schreb.; E+) mixed with common bermudagrass [Cynodon dactylon (L.) Pers.] and other forages; (ii) endophyte‐free tall fescue (E−) overseeded into dormant common bermudagrass; and (iii) orchardgrass (OG; Dactylis glomerata L.) established under the same conditions as E−. The E− and OG pastures were grazed with either twice weekly (2W) or twice monthly (2M) rotation schedules, but E+ was grazed only as 2M. Across 41 sampling dates (2000 through 2003) the mean forage mass across all forage systems was 3809 kg ha−1, and there was an interaction of forage system and sampling date (P = 0.001). In vitro dry matter disappearance (IVDMD) and crude protein (CP) varied (P < 0.0001) with sampling date in seasonal patterns that were generally predictable. Frequencies of tall fescue in E− and E+ pastures increased (P < 0.10) over years, reaching numerical maxima (61 to 72%) at the end of the trial. For OG, frequencies reached numerical maxima of 52 and 42% in 2W and 2M pastures, respectively, but then declined (P < 0.10) over time, ending at 39 and 24%, respectively. At the end of the trial, reinfection of OG pastures by rogue E+ plants reached a numerical maximum frequency of only 10%, and concentrations of total ergot alkaloids in tall fescue plants from E− pastures were only about 25% of those for E+ pastures, thereby suggesting that pasture toxicity can be reduced substantially for at least 5 yr using these alternative forage systems.
Genetic Variation in Dry Matter Production and Nutritional Characteristics of Meadow Bromegrass under Repeated Defoliation
Authors: Jensen Kevin B. , Robins J. G. , Waldron Blair L. , Peel Michael D.
Published: July 2006

Meadow bromegrass (Bromus riparius Rehm.) has gained interest as a highly productive pasture grass that can be used under management intensive grazing with limited irrigation. In 1999, 28 cloned parents and half‐sib families of meadow bromegrass were each planted in a randomized complete block design to evaluate genetic variation of meadow bromegrass for dry matter yield (DMY) (Harvests 1 to 6), forage quality under repeated defoliation (Harvests 1, 3, and 5), and investigate intercharacter correlations. Narrow‐sense heritability estimates and their standard errors for DMY at Harvests 2, 3, and 4 were 0.89 ± 0.32, 0.59 ± 0.28, and 0.53 ± 0.29, respectively. However, at Harvest 1 and 5, standard errors of the heritability estimates for DMY were equal to or greater than the estimates. All heritability estimates for crude protein (CP) were at least twice their standard errors at Harvests 1, 3, and 5. High narrow‐sense heritabilities at Harvest 5 for acid detergent fiber (ADF) suggest that selection on forage harvested later in the growing season might be more efficient than forage harvested earlier in the season. Combined across years and within harvests, narrow‐sense heritability estimates and standard errors for neutral detergent fiber (NDF) were 0.66 ± 0.29, 0.47 ± 0.30, and 0.71 ± 0.28, respectively. Based on correlations, it seems reasonable to assume that when selecting for increased DMY that ADF and NDF will increase and that CP and IVTD will decrease in this population.
Fertilization and Mowing Effects on Unimproved Mixed‐Species Hayfields in Quebec, Canada
Authors: Eriksen‐Hamel Nikita S. , Whalen Joann K.
Published: July 2006

The objective of this experiment was to evaluate the response of two unimproved mixed‐species hayfields in Quebec, Canada, to management regimes of high fertilization and intensive mowing. Dry matter and nutrient yields, tissue nutrient concentrations, and soil nutrient pools were determined in Bromus–Poa and Pleum–Lolium hayfields fertilized with inorganic fertilizer, liquid dairy manure, or no fertilizer and mown at different intensities (every 2 wk or unmown, during a 12‐wk period). Dry matter and nutrient yields, and tissue nutrient concentrations were similar in plots receiving inorganic and dairy manure fertilizers, but the dry matter yield was 0.6 to 2.8 Mg ha−1 higher in fertilized plots than the unfertilized control. Repeated mowing reduced dry matter yield by 1.5 to 2.7 Mg ha−1, however, tissue nutrient concentration and nutrient yield were greater in mown than unmown plots. The apparent N recovery in a mown, fertilized Pleum–Lolium hayfield was greater than 100%, as the nutrient yields (143 kg N ha−1) were greater than the N fertilizer input of 75 kg N ha−1 Soil NO3− and microbial biomass N concentration were significantly (P < 0.05, Tukey test) lower in fertilized plots that were mown every 2 wk than unmown during the study period. Frequent mowing may be a management option that can reduce soil residual N and thus limit NO3− leaching from mixed‐species hayfields.
The Implications Of Godparental Ties Between Indians And Spaniards In Colonial Lima
Authors: Charney Paul
Published: July 2006

Spaniards introduced into the New World a custom called godparenthood,compadrazgo, which had both formal and informal connotations. The more formal, ritual ties were usually established at baptism, confirmation, or marriage ceremonies between the parents and coparents (comadresandcompadres), and the godchildren (ahijados) and godparents (padrinosandmadrinos). The termscomadreandcompadrealso connote an informal reference to adults in a relationship of mutual respect and friendship which differed from the ritual forms of godparentage. Godparental relations established formally or informally among Spaniards and Indians, as well as between the two races pervaded colonial society.
Summary Guide to Spanish Florida Missions andVisitasWith Churches in the Sixteenth and Seventeenth Centuries
Authors: Hann John H.
Published: July 2006

The early European presence in California and in the American Southwest in general is identified with missions. Although missions were equally important in Spanish Florida and at an earlier date, the average American does not associate missions with Florida or Georgia. Indeed, as David Hurst Thomas observed in a recent monograph on the archaeological exploration of a site of the Franciscan mission of Santa Catalina de Guale on Georgia's St. Catherines Island, the numerous missions of Spanish Florida have remained little known even in scholarly circles. And as Charles Hudson has noted, this ignorance or amnesia has extended to awareness of the native peoples who inhabited those Southeastern missions or were in contact with them, even though these aboriginal inhabitants of the Southeast “possessed the richest culture of any of the native people north of Mexico … by almost any measure.” Fortunately, as Thomas remarked in the above-mentioned monograph, “a new wave of interest in mission archaeology is sweeping the American Southeast.” This recent and ongoing work holds the promise of having a more lasting impact than its historical counterpart of a half-century or so ago in the work of Herbert E. Bolton, Fr. Maynard Geiger, OFM, Mary Ross, and John Tate Lanning. Over the fifty odd years since Lanning'sSpanish Missions of Georgiaappeared, historians and archaeologists have made significant contributions to knowledge about sites in Spanish Florida where missions or mission outstations and forts or European settlements were established. But to date no one has compiled a comprehensive listing from a historian's perspective of the mission sites among them to which one may turn for the total number of such establishments, their general location, time of foundation, length of occupation, moving, circumstances of their demise and the tribal affiliation of the natives whom they served. This catalog and its sketches attempt to meet that need.
Consent to Ascent TheBaltimoreAffair and the U.S. Rise to World Power Status
Authors: Goldberg Joyce S.
Published: July 2006

The city where trouble began in 1891, Valparaíso, Chile, was a memorable place. Benjamín Vicuña Mackenna, the nineteenth-century Chilean historian and political leader, has rightly written that the history of Valparaíso has been the history of the sea. An old port, once a more important city than it is now, built around and especially on top of steep hills reached by rickety lifts, Valparaíso still has a grace and character unlike that of most other ports—its landscape resembles an untamed San Francisco. At one time it was a thriving commercial center and hub of naval activity, important not only for the direction of Chilean history but for that of much of South America as well. In the nineteenth century, with Chilean independence and the later decay of the Peruvian port of Callao, Valparaíso rapidly became the maritime capital of the Pacific and an important focus of naval enterprises for continental defense. Then, after decades of prosperity, its importance declined and the fortunes of other coastal cities arose.
Caciques and Conversion: Juan Atonal and the Struggle for Legitimacy in Post-Conquest Chiapas
Authors: Gosner Kevin
Published: July 2006

In September, 1584, during an episcopalvisitato Chiapa de Indios, a group of townspeople came to the bishop, Fray Pedro de Feria, to accuse the patriarch of one of the principal lineages in the town of leading a clandestine cult. They said that, in nearby Suchiapa, a “gran junta” composed of twelve Indians who called themselves the Twelve Apostles gathered at night to walk among the hills and caves, and to perform “demonic rites against our Christian religion.” With them, Feria was told, went two women. One they called Santa María; the other, Magdalena. Together the cultists carried out ceremonies in which they transformed themselves into gods and goddesses. In their divine form, the women were said to have the power to conjure storms, and to give many riches to whomever they pleased. Feria would report that they had “many other superstitutions and vanities” which he compared to the Alumbrados or Illuminist sect that had been widely popular in Spain during the 1520s and been condemned by the Inquisition.
Commercial Foot Soldiers of the Empire: Foreign Merchant Politics in Tampico, Mexico, 1861-1866
Authors: French John D.
Published: July 2006

During the period from Mexican independence in 1821 to the end of the French intervention in 1867, Mexico's primary tie to the outside world was based on trade. The foreign merchants, who monopolized this activity, played a crucial role in the economic, diplomatic, and political life of Mexico. The current literature on these nineteenth century merchants includes studies of foreign groups, such as the French, detailed case studies of individual entrepreneurs, firms and merchant families, and one work that provides a unique state-centered perspective on the Mexican/merchant nexus. None, however, have tried to conceptualize the role of foreign merchants as a whole, across national lines and individual rivalries, in the port cities that were the central arena of contact and conflict with the outside world.