cssi/SciSciGPT-SciSciNet huggingface dataset:
Micromechanical Model of Crack Growth in Fiber Reinforced Brittle Materials

A model based on the micromechanical mechanism of crack growth resistance in fiber reinforced ceramics is presented. The formulation of the model is based on a small scale geometry of a macrocrack with a bridging zone, the process zone, which governs the resistance mechanism. The effect of high toughness of the fibers in retardation of the crack advance, and the significance of the fiber pullout mechanism on the crack growth resistance, are reflected in this model. The model allows one to address issues such as influence of fiber spacing, fiber flexibility, and fiber matrix friction. Two approaches were used. One represents the fracture initiation and concentrated on the development of the first microcracks between fibers. An exact closed form solution was obtained for this case. The second case deals with the development of an array of microcracks between fibers forming the bridging zone. An implicit exact solution is formed for this case. In both cases, a discrete fiber distribution is incorporated into the solution.
Marine minerals at the new millenium

A new view of marine minerals is emerging that links inorganic with organic processes and raises environmental issues. On the continental shelf recovery of common materials comprising sand and gravel for construction and seawater for desalinization will grow. Mineral sands containing Au, Pt, gemstones, Snor Ti-minerals will be targeted and traced seaward. Diamonds have developed into a mining industry offshore Namibia and South Africa with annual output near US$1 billion. Deep seabed deposits comprising manganese nodules (Mn, Cu, Ni, Co; water depths 4000-6000 m), ferromanganese crusts (Mn, Co, Ni, Pt; water depths 500-2500 m), and massive sulfide deposits (Cu, Fe, Zn, Ag, Au; water depths 2000-4000 m) will be mined. Ferromanganese crusts accumulate on rocky seabed elevations of seamounts, islands, and oceanic plateaus where they may be difficult to harvest. Massive sulfides are deposited from seafloor hot springs, which are sources both of the metals and of chemical energy utilized by heat-tolerant bacteria to manufacture their food at the base of a vent ecosystem linking inorganic with organic processes. The bacteria are sources of organic compounds for use in industrial processes and pharmaceuticals and may themselves relate to the base of the evolutionary tree of life. Mining of the metallic minerals and bioproducts produced at seafloor hot springs has the potential to benefit society and to threaten the environment. A theme of the 21st century will be reconciling the conflict between societal benefits and environmental impacts of marine mining.
Relationship between prenatal lead exposure and infant blood lead levels.

Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6 months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10 μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r = 0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6 months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5 μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52–277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6 months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6 months of age.
Nuclear resonance fluorescence with the 105-keV E1 transition of Gd155 using an ultracentrifuge

Abstract Resonance fluorescence from the 105-keV level in Gd155 was studied with the centrifuge method. Assuming a branching ratio Γ0/Γ=0.69 for this E1 transition to the ground state, a mean life τγ=6.0−2+6×10−10 sec was calculated from the measured resonance scattering at different source velocities. This lifetime and τγ of the 87-keV level measured by Vergnes are consistent with the E1 lifetime predictions of the Nilsson model if the 87-keV orbital is [ 651 3 2 ] and the 105-keV orbital is [ 643 5 2 ] at a nuclear deformation δ≈0.26.
Is there a simple bi-polar ocean seesaw?

Abstract Using an atmosphere–ocean coupled model, the climate response to an idealized freshwater input into the Southern Ocean is studied. In response to the freshwater input, the surface waters around Antarctica freshen and cool. As the addition of freshwater continues, the fresh, surface anomalies spread throughout the world ocean in contrast to ocean-only experiments and North Atlantic experiments using coupled models. Because of the fundamental difference in altering sea surface salinity (SSS) from the two sources (northern hemisphere and southern hemisphere), a bi-polar seesaw fails to develop in the ocean, at least in our coupled atmosphere–ocean experiments. Control ocean-only experiments with mixed boundary conditions and similar short-term southern freshwater impacts match the results of the coupled experiments. Based on these experiments, we argue that the concept of ocean bi-polar seesaw should be taken with some caveats.
Creep-Crack Growth by Damage Accumulation in a Glass-Ceramic

The growth rate, near-tip creep response, and damage processes of creep cracks in a pyroceram glass-ceramic were studied under tensile loading at elevated temperatures. The rates of crack extension were characterized as a function of the applied stress intensity factor. The damage processes which occurred near the crack tip and led to creep crack extension were identified using a replica technique and by direct observations in a scanning electron microscope equipped with a high-temperature loading stage. The accumulated creep strains near the crack tip were measured via the stereoimaging technique. The results indicate that creep-crack growth in the pyroceram glass-ceramic occurs in both continuous and discontinuous manners, with the damage processes manifested as the nucleation, growth, and coalescence of inhomogeneously distributed cavities and microcracks. Measurements of the total accumulated creep strain near the crack tip suggest that crack extension follows a critical strain criterion. Both the microcrack density and the total accumulated creep strain show similar dependence with distance from the crack tip. These observations suggest that damage accumulation and crack extension in the glass-ceramic are controlled by the near-tip creep rates.
Thermoelasticity of perovskite: An emerging consensus

The current status of how well the thermoelastic properties of (Mg,Fe)SiO3 perovskite are known was addressed at a Special Session and Panel Discussion during the Fall 1993 AGU Meeting. Interest in the topic stems from the fact that silicate perovskite is the predominant mineral phase of the Earth's lower mantle, a region comprising over 60 (atomic) percent of the planet. Consequently, the properties of silicate perovskite largely control the evolution and state of the planetary interior. The view emerging from the discussion was that after 10 years of intense study, the thermal and elastic properties of silicate perovskite are finally coming into focus. Indeed, the bulk modulus of (Mg,Fe)Si03 perovskite is now among the best determined of any mineral's. In addition, this is perhaps the only material for which the thermal expansion coefficient has been directly measured at lower-mantle conditions of pressure and temperature. A number of other properties of silicate perovskites—some of which were discussed peripherally in the Special Session—are the subject of ongoing research and remain to be established. In contrast, there seems to be a growing consensus regarding several key thermoelastic properties that are vital for understanding the Earth's deep interior.
Influence of modifying agents on enzyme inactivation studies. An analysis using a series mechanism and a form of the hill-type equations

A series deactivation model is utilized to theoretically examine the influence of different modifying agents on enzyme deactivation kinetics. A form of the Hill-type equation is used to describe the effect of the modifying agents on the model parameters. Modification-induced inactivation equations are presented for the acetylation and succinylation of E. Coli asparaginase, for the site-specific reagent and substrate modification of flavocytochrome b(2) from Baker's yeast, and for the guanidinium chloride inactivation of cathepsin D. The analysis of more data for these and other enzymes would help further substantiate the technique presented and enhance the applicability of the model.
Carbon nanotube bundle interconnect: Performance evaluation, optimum repeater size and insertion for global wire

To remove the bottleneck of the interconnect especially at semi-global and global level, performance evaluation of local, semi global, and global interconnect is presented in this paper based on carbon nanotube (CNT) interconnect bundle model. For the greater length of the wire, a methodology is presented to find the optimum insertion and size of buffer for CNT bundle interconnects. The performance analysis for repeater shows that the CNT bundle can run 2.58 times longer without repeater insertion and requires 31% less buffer size than Cu wire.
Optimal hedging and equilibrium in a dynamic futures market

Abstract This paper considers an agent maximizing the expected utility of the sum of the terminal value of a fixed portfolio of spot market assets and the terminal value of a margin account on a futures trading position. Closed-form solutions for the optimal hedging strategy are provided in several special cases.
Synthesis of 3-deoxy-3-fluoro-d-mannose and 4-deoxy-4- fluoro-d-mannose

Abstract Addition of potassium cyanide to 2-deoxy-2-fluoro- d -arabinose ( 1 ) at pH 7.8 followed by catalytic hydrogenation over palladium—barium sulfate (5%) produced 3-deoxy-3-fluoro- d -glucose ( 4 ) and 3-deoxy-3-fluoro- d -mannose ( 5 ) in 25 and 40% isolated yields, respectively. The epimeric sugars were purified by passage through a column of Dowex-50W × 8 (Ca 2+ ). In a similar manner, 3-deoxy-3-fluoro- d -arabinose ( 6 ) was converted into 4-deoxy-4-fluoro- d -glucose ( 9 ) and 4-deoxy-4- fluoro- d -mannose ( 10 ) in 27 and 45% isolated yields, respectively. Deoxyfluorohexoses 4, 5, 9 and 10 enriched with carbon-13 and carbon-14 at C-1 have been prepared by this procedure.
Greenhouse and Field Nursery Evaluation for Potato Common Scab Tolerance in a Tetraploid Population

Potato common scab (Streptomyces scabies (Thaxt.) Waksman & Henrici) is a major disease of potato (Solanum tuberosum L.), due to the unmarketability of affected tubers. For identification of the most common scab-tolerant material, and for developing molecular markers for common scab tolerance, more information is needed on the genetic basis of common scab tolerance. Phenotyping common scab susceptibility is difficult because of the large variability in disease symptoms among tubers from a single plant, ranging from no common scab to severe pits. Two years of field data were collected for scab reaction on a segregating tetraploid population (MSL603, 160 individuals). Continuous variation in common scab susceptibility phenotype was observed among the progeny, with a normal distribution suggesting common scab disease phenotype is a genetically complex trait. Transgressive segregants were also observed, but they are skewed toward susceptibility. A greenhouse-based screening procedure was evaluated to discern tolerant from susceptible potato lines. A subset of ten individuals from this population were selected (five resistant, five susceptible). For the greenhouse study, soil was inoculated with a pathogenic S. scabies strain MSDPZ at a concentration of 3 X 108 CFU/ml. This greenhouse assay effectively discerned tolerant and susceptible individuals. There was a moderate correlation between the greenhouse study and the field trial. The greenhouse assay may provide information that would complement field data in identifying resistant clones.
Features of the triggering mechanism for single event burnout of power MOSFETs

The feedback mechanism leading to second breakdown and burnout in a power MOSFET is reviewed, and critical device design parameters are identified and chosen with regard to electrical specifications. Assuming typical parameters, the avalanching conditions in the space-charge region of the collector current densities. It is shown that the space charge associated with the collector current density modifies the electric field profile so that with increasing collector current, the avalanche multiplication factor rises in a peak, then declines to a valley, and eventually rises monotonically. This behavior can be explained in simple terms and could lead to a stable avalanching condition with a current density too low to damage the structure. This condition can be initiated by heavy ions with energies below a certain threshold. Ion energies beyond the threshold drive the avalanching process into the region of monotonic increase of the avalanche multiplication factor and lead to runaway and burnout. The threshold for runaway varies widely with changing configurations of the p/sup +/-plug and the p-body region, suggesting the possibility of configurations that are immune to burnout. Threshold currents in a typical hex cell are assessed. >
Mechanical Properties of Arteries in Vivo

Methods have been assembled permitting the simultaneous recording of intra-arterial pressure and arterial diameter with sufficient accuracy so that the mechanical properties of arteries in vivo, under physiologic conditions, can be derived. The analysis necessitates finding the relationships between 5 simultaneous variables; hence the data were recorded on magnetic tape and processed by analog and digital computer technics. Analysis of the data established the fact that the mechanical properties of arteries can be described by a linear, first-order differential equation whose coefficients can be defined as the moduli of elasticity and viscosity. Furthermore, the magnitudes of the coefficients were evaluated. The strain which the arteries undergo as a result of arterial pulse pressure variations is normally between 0.01 and 0.04, i.e., between 1 and 4 per cent change in circumference. The total strain associated with marked constriction and dilation does not usually exceed 10 per cent. Therefore, it is est...
Difficulty taking medications, depression, and health status in heart failure patients.

Abstract Background Little is known about medication nonadherence in heart failure populations. We evaluated the association between 1 aspect of medication nonadherence, patient-reported difficulty taking medications as directed, and health status among heart failure outpatients, and then examined whether this association was explained by depression. Methods and Results A total of 522 outpatients with left ventricular ejection fraction P = .008) and more depressive symptoms (43.8% versus 27.1%; P = .006). Adjusting for demographic and clinical factors had little effect on the association between difficulty taking medications and health status (8.0 ± 3.2 point lower KCCQ scores; P = .01); however, the relationship was attenuated with adjustment for depressive symptoms (4.7 ± 2.9 point lower KCCQ scores; P = .11). Conclusions Among heart failure outpatients, difficulty taking medications is associated with worse health status. This association appears to be explained, in part, by coexistent depression. Future studies should evaluate interventions such as depression treatment to improve medication adherence and health status.
An Analytic Approximation to Radiative Blast Wave Evolution

The evolution of the well-known Sedov-Taylor adiabatic blast waves can be derived analytically using simple physical arguments. However, radiative blast waves with energy loss concentrated at the shock front have only been studied numerically. Here we show that if the shock radius evolution can be expressed as R ~ (at)n, then using an approximation similar to that discussed by Zeldovich & Raizer for the adiabatic case, we can derive simple analytic relations for n and a as functions of the pre- and postshock adiabatic indices, the energy loss fraction e, the initial energy E0, and initial deposition size R0. These analytic results are in excellent agreement with previous numerical results. We also find that the results are much more sensitive to the postshock adiabatic index in the central cavity than the preshock adiabatic index.
Anterior Cingulate Desynchronization and Functional Connectivity with the Amygdala During a Working Memory Task Predict Rapid Antidepressant Response to Ketamine

Pregenual anterior cingulate cortex (pgACC) hyperactivity differentiates treatment responders from non-responders to various pharmacological antidepressant interventions, including ketamine, an N-methyl-D-aspartate receptor antagonist. Evidence of pgACC hyperactivition during non-emotional working memory tasks in patients with major depressive disorder (MDD) highlights the importance of this region for processing both emotionally salient and cognitive stimuli. However, it is unclear whether pgACC activity might serve as a potential biomarker of antidepressant response during working memory tasks as well, in line with previous research with emotionally arousing tasks. This study tested the hypothesis that during the N-back task, a widely used working memory paradigm, low pretreatment pgACC activity, as well as coherence between the pgACC and the amygdala, would be correlated with the clinical improvement after ketamine. Magnetoencephalography (MEG) recordings were obtained from 15 drug-free patients with MDD during working memory performance 1 to 3 days before receiving a single ketamine infusion. Functional activation patterns were analyzed using advanced MEG source analysis. Source coherence analyses were conducted to quantify the degree of long-range functional connectivity between the pgACC and the amygdala. Patients who showed the least engagement of the pgACC in response to increased working memory load showed the greatest symptomatic improvement within 4 h of ketamine administration (r=0.82, p=0.0002, false discovery rate (FDR) <0.05). Pretreatment functional connectivity between the pgACC and the left amygdala was negatively correlated with antidepressant symptom change (r=-0.73, p=0.0021, FDR <0.05).These data implicate the pgACC and its putative interaction with the amygdala in predicting antidepressant response to ketamine in a working memory task context.
Preoperative platelet transfusions and perioperative red blood cell requirements in patients with thrombocytopenia undergoing noncardiac surgery

Perioperative hemorrhage necessitating red blood cell (RBC) transfusion is an undesirable surgical complication, as RBC transfusion has consistently been associated with adverse patient outcomes.1–7 In addition, the economic toll of transfusion is increasingly well recognized, with nearly 3 million units of RBCs transfused perioperatively each year in the United States, representing more than $2.25 billion.8,9 Furthermore, hospital blood supplies are limited with more than one-quarter of US hospitals reporting surgical delays due to insufficient blood supplies and 10% of hospitals reporting at least 1 day per year where surgical blood needs cannot be met.8 It is therefore imperative in this era of increased scrutiny on health care quality that transfusion practices be uniquely tailored to clinical scenarios in which transfusion may provide evidence-based improvement in patient outcome. Preoperative platelet (PLT) counts and coagulation tests have long been used as a marker of perioperative bleeding risk; however, the value of this practice remains unclear.10 Prior studies have shown that routine preoperative coagulation tests, including PLT counts, do not reliably predict surgical bleeding complications,11–15 prompting the 2012 American Society of Anesthesiologists Task Force on Preanesthesia Evaluation to recommend against this practice unless clearly indicated by patient history and physical examination.16 However, recent evidence suggests that pre-operative thrombocytopenia is associated with significantly higher risk of blood transfusion and death in noncardiac surgery, prompting the authors to question recommendations against routine preoperative screening.17 In clinical practice, administration of PLTs in those with thrombocytopenia is frequently performed in the preoperative period in an attempt to mitigate perioperative bleeding complications including RBC requirements, surgical blood loss, and reoperation for bleeding. However, evidence to support or guide such perioperative transfusion practices is lacking.18 As such, the decision to transfuse in the perioperative period is often based on the gestalt or clinical experience of the surgeon or anesthesiologist rather than by quality evidence suggesting benefit. Moreover, PLT transfusions are associated with substantial patient risk, including a myriad of allergic, infectious, and inflammatory transfusion reactions.19,20 This investigation was designed to determine the relationship between preoperative PLT transfusion and perioperative bleeding complications in patients with thrombocytopenia undergoing noncardiac surgery in a large, tertiary care center. We hypothesized that while preoperative thrombocytopenia (i.e., PLT count ≤ 100 × 109/L) would be predictive of perioperative RBC requirements, prophylactic PLT administration would not attenuate this risk. In addition, we aimed to assess the impact of preoperative PLT transfusion on other patient-important outcomes.
The Language of Change: Finding Words to Define Culture Change in Long-Term Care

Many senior living organizations are working to transform their institutional character into home and community. This undertaking amounts to a virtual cultural shift, known in the industry as culture change. Culture change is receiving growing popularity in the senior living industry; however the majority of organizations have yet to begin tackling this transformation. One of the contributions to this hesitancy may be that no universal explicit definition of culture change is accepted within the industry. This article, based on an extensive literature review, examines the current definitions within the culture change literature and proposes a new definition that may be helpful in understanding and undertaking this challenging holistic transformation.
Why I Haven't Retired

What is written below is, as requested by the editor of AR Condensed Matter Physics, a set of recollections and insights gained from my personal trajectory that starts from my earliest years and continues on until now. I have been a participant in the growth of solid state physics from its early quantum insights to the highly popular foci of today’s vibrant condensed matter science community, while working at three institutions that helped spearhead this growth—UC Berkeley, Bell Labs, and Stanford University. It is rare to be actively involved in any creative enterprise for more than six decades. I credit my good fortune to stimulating science; great students and colleagues; a happy home; warm friendships; and, evidently, to my having inherited good genes.
Community radio for development in South Asia: A sustainability study

Community radio (CR) is a participatory medium and a subset of radio broadcasting. It is an inexpensive and popular way for disseminating content (information, news, entertainment, etc.) CR is designed to increase availability of localized information, media access and empowerment, and even market based growth and societal resource distribution for the community. We examine the sustainability of CR as a tool towards achieving the overall development in the South Asian region. A cross-country comparison of CR in areas including people's participation, regulatory scenarios, human resource development, technology usage trends, financial practices etc. shows a wide variety of CR applications and challenges. An indepth analysis of financial data and practices of several Nepalese CR stations (rural, urban, and semi-urban) alongside regulatory and anecdotal references from India and Bangladesh shows potential viability through advertising and other mechanisms. Even with an advertisement cap of 5 minutes per hour, every station shows the potential of achieving financial sustainability by selling a fraction of the allotted ad time (7%-46%). Our model shows that the monthly operating expenditure of types of stations turns out to be more significant than the annualized capital expenditure. In our analysis (and borne out in the real world), of the three considered stations, the semi-urban station has the highest cost per listener. Stochastic cost modeling of real world CR data show the trend of increased cost for content development is a trade-off for expanding the listener base and transmission time. We conclude with a proposed set of policy and operating recommendations to enable CR to play a significant role in overall South Asian development.
Role of Cbfa1/Runx2 in the fluid shear stress induction of COX-2 in osteoblasts.

Abstract Induction of cyclooxygenase-2 (COX-2) is thought to be important for the anabolic effects of mechanical loading. The transcription factor Cbfa1/Runx2 is essential for osteoblastic differentiation. We examined the role of Cbfa1 in the fluid shear stress (FSS) induction of COX-2 in MC3T3-E1 cells stably transfected with a COX-2 promoter-luciferase reporter. Cells were subjected to FSS for 30 min and returned to static culture (post-FSS). COX-2 mRNA and promoter activity peaked 0.5–1 h and 2–3 h, respectively, post-FSS. Mutation of the Cbfa1 consensus sequence at −267/−261 bp decreased the FSS fold-induction of luciferase activity by 50%. On electrophoretic mobility shift assay (EMSA), proteins binding to an oligonucleotide spanning the Cbfa1 site were supershifted by specific antibody to Cbfa1. FSS did not increase Cbfa1 binding on EMSA or Cbfa1 mRNA or protein levels. These data suggest that transcriptional activity of Cbfa1, independent of its level of expression, is necessary for maximal FSS induction of COX-2 in osteoblasts.
Factors Contributing to Increasing Marital Stability in the United States

Results from the 1995 National Survey of Family Growth indicate that marriages contracted after 1980 are becoming more stable. This article examines several individual characteristics in search of an explanation for increasing stability. A person-year file is created and logistic regression is used to determine which covariates account for the negative effect of year in a model predicting the likelihood of marital dissolution. Increasing experience of premarital sex, premarital birth, cohabitation, and racial and religious heterogamy are detracting from marital stability. However, rising age at marriage and, to a lesser degree, increased education are associated with increasing marital stability. These latter effects more than counterbalance the factors associated with instability leading to an overall decline in the rate of marital dissolution.
A MULTISTATE CAPTURE-RECAPTURE MODEL USING A POSTERIORI CLASSIFICATION TO ENHANCE ESTIMATION OF MOVEMENT RATES

Abstract Biologists commonly use multistate capture-recapture models to estimate movement and survival rates of animals. Recent improvements to genetic and stable-isotope techniques have created the potential for making a posteriori determinations of an animal's location. Here, I present a new multistate model structure that incorporates captured animals' backdated locations. To provide data for this model, I developed a computer simulation in which birds moved between two geographic strata during three time periods. Birds were captured and assigned mortality, and multistate capture histories were recorded. I enhanced capture histories for birds using data from simulated stable-isotope analyses. I then used the modified multistate model to estimate survival, movement, and recapture probabilities. I evaluated the ability of stable-isotope data to more precisely estimate movement over a range of recapture and movement rates. In each of nine simulations, information from stable isotopes improved the precisio...
HOUSING, SPRAWL, AND THE USE OF DEVELOPMENT IMPACT FEES: THE CASE OF THE INLAND EMPIRE

This article is concerned with the economics of excessively large and socially costly suburbanexpansionandattemptstosummarizeandorganizethemaineconomicarguments associated with sprawl due to single-family residential home construction. We also apply standard welfare economics and price policy instruments to the issue of suburban sprawl in order to suggest ways in which economics can participate in and inform the debate over sprawl. The article uses the Inland Empire, which includes the valley regions of San Bernardino and Riverside Counties in Southern California east of Los Angeles, as a case study. (JEL R11, R14, Q24) I. INTRODUCTION This article is concerned with the economics of excessively large and socially costly suburban expansion and attempts to summarize and organize the main economic arguments associated with sprawl due to single-family residential home construction. The topic is of interest not only because the social costsof sprawl may be high but also because what seem like fairly clear economic issues have been at least partially obscured by the debate over sprawl. This has led to obfuscation to the point that wellaccepted economic notions have not been able to fulfill their clarifying potential and standard economic instruments to internalize externalities remain on the sidelines. This article presents some of these confusions and debates for review. We also apply standard welfare economics and price instruments to the issue of suburban sprawl in order to suggest ways in which economics can participate in and inform the debate. The article uses the Inland Empire, which includes the valley regions of San Bernardino and Riverside Counties in Southern California east of Los Angeles, as a case study. TheInlandEmpireisverylarge,withapopulation of about 3.8 million. Indeed, though dwarfed by Los Angeles County if the region were a state, it would be larger than exactly half the U.S. states (California Department of Finance Web site; Husing, 2005). The region is a good one for the purpose because key policy issues related to property rights, housing affordability, and externalities closely associated with housing choices that are of nationwide interest are being debated particularly actively in the region. Part of the reason sprawl and its effects are so much in the forefront in the Inland Empire is that the region has experienced an enormous building boom during the past 10 yr. In 2004, there were
Approaches to Observation in Classroom Research: Observation from an Ecological Perspective.

The TESOL Quarterly publishes brief commentaries on aspects of qualitative and quantitative research. For this issue we asked two researchers to discuss their respective approaches to classroom observation in L2 research.
Mechanisms of Deposition of a Carbonate Mud Spit: Ramshorn Spit, Eastern Florida Bay: ABSTRACT

The turtle grass (Thalassia testudinum) community has a significant influence on sedimentation in Florida Bay, but the roles other processes may play in the buildup of mud bank and spit sediments are poorly understood. Samples from cores taken from Ramshorn Spit and Ramshorn Shoal were classified into 4 basic types on the basis of particle size distribution, organic content, and faunal assemblages. In order of increasing volumetric importance they are: (1) very thin, discontinuous shelly packstones, representing overbank or storm deposits; (2) thin, continuous basal shelly packstones, the initial marine deposit on the Pleistocene bedrock surface; (3) muddy wackestones, of variable thickness, deposited in the presence of a seagrass community; (4) very thick, faintly lamina ed fine mudstones, with very sparse fauna, representing weak current-transported sediments settling out of suspension. Discriminant function analysis confirms the classifications and shows that these sediment layers are indeed correlatable between cores. Interpretation of the core logs from Ramshorn Spit indicates a definite change in stratigraphy southwestward from the spit and bank junction to the tip of the spit itself. The different sediment layers show a small but significant inclination to the southwest. Throughout its depositional history, Ramshorn Spit seems to have been actively accreting outward into the surrounding "lake" by means of a current-transported fine mud fraction. After settling out at the growing tip of the spit, the sediments are subsequently stabilized at some later time by a turtle-grass cover. End_of_Article - Last_Page 266------------
Effects of vessel geometry and catheter position on dose delivery in intracoronary brachytherapy

In-stent restenosis is commonly observed in coronary arteries after intervention. Intravascular brachytherapy has been found effective in reducing the recurrence of restenosis after stent placement. Conventional dosing models for brachytherapy with beta (/spl beta/) radiation neglect vessel geometry as well as the position of the delivery catheter. This paper demonstrates in computer simulations on phantoms and on in vivo patient data that the estimated dose distribution varies substantially in curved vessels. In simulated phantoms of 50-mm length with a shape corresponding to a 60/spl deg/-180/spl deg/ segment of a respectively sized torus, the average dose in 2-mm depth was decreased by 2.70%-7.48% at the outer curvature and increased by 2.95%-9.70% at the inner curvature as compared with a straight phantom. In vivo data were represented in a geometrically correct three-dimensional model that was derived by fusion of intravascular ultrasound (IVUS) and biplane angiography. These data were compared with a simplified tubular model reflecting common assumptions of conventional dosing schemes. The simplified model yielded significantly lower estimates of the delivered radiation and the dose variability as compared with a geometrically correct model (p < 0.001). The estimated dose in ten vessel segments of eight patients was on average 8.76% lower at the lumen/plaque and 6.52% lower at the media/adventitia interfaces (simplified tubular model relative to geometrically correct model). The differences in dose estimates between the two models were significantly higher in the right coronary artery as compared with the left coronary artery (p < 0.001).
Second language syntax: A generative introduction. By Roger Hawkins. Oxford: Blackwell, 2001. Pp. xviii, 383. Paper. $39.95.

This book is a pleasure for the second language (L2) researcher to read, and a challenge for the teacher of second language acquisition (L2A) theory to use. It offers an extremely clear and engaging introduction and overview of current L2A research from the generative 380 Reviews perspective. It successfully brings classical older findings to bear on the contemporary research issues. It highlights the most important issues in the field with admirable intellectual precision and honesty. At the same time, it is an introductory text that also has another agenda, namely, presenting and arguing for the author's own theory of second language development. Thus, it is not clear whether the text is intended exclusively as a teaching aid or as a research book. I am afraid the combination of the two is daunting for the unsuspecting reader.
Body, nation, and consubstantiation in Bolivian ritual meals

During a remarkable period of official ethnic recognition and indigenous political mobilization in Bolivia, farmers in the rural Municipality of Mizque have invested increasing energy in ritual meals widely characterized as indigenous, expanding the number of meals celebrated and increasing their spatial distribution. Multisited ethnographic study of how people connect to body, place, and identity shows that the intense corporal experiences and tangible materiality of these ritual meals contrast with tendencies of official multiculturalism to privilege symbols and products of indigenous culture while disregarding the substance of indigenous bodies and the material bases of their survival. Consubstantiation in ritual meals resonates with other collective bodily practices that are gaining prominence in Bolivia, including mass manifestations and constituent assemblies, to point toward possibilities for a new kind of civil society grounded in concern for the ethnic identities and for the bodily and material subsistence of its diverse members.
Information technology investment and adoption: a rational expectations perspective

This study examines the potential applications of the rational expectations hypothesis (REH) in information technology (IT) investment and adoption decision-making. Although REH has been widely used in other areas of microeconomics and macroeconomics, we have not yet seen common use of the related theory in the information systems (IS) field. In this paper, we introduce REH theory together with some of its applications in non-IS/IT areas. Despite the fact that rationality is commonly assumed in economic analyses, the REH's rather strong assumptions make it a unique theory and allow us to offer new perspectives on IS/IT adoption and investment decision-making. We discuss how the theory can potentially be applied in IS/IT cases by presenting several illustrative examples. We then examine issues in the evaluation of adoption and investments of new and emerging ITs. Based on the theory, we argue that managers that are risk-averse are most likely to wait and adopt or invest in new and emerging technologies later than managers that are risk-takers. We suggest that for the earlier adoption or investments, the conventional method for estimating investment value may not be appropriate. We also suggest research directions with regard to the application of REH in the IS field.
Dendritic Cells: Translating Innate to Adaptive Immunity

The innate immune system provides many ways to quickly resist infection. The two best-studied defenses in dendritic cells (DCs) are the production of protective cytokines-like interleukin (IL)-12 and type I interferons-and the activation and expansion of innate lymphocytes. IL-12 and type I interferons influence distinct steps in the adaptive immune response of lymphocytes, including the polarization of T-helper type 1 (Th1) CD4+ T cells, the development of cytolytic T cells and memory, and the antibody response. DCs have many other innate features that do not by themselves provide innate resistance but are critical for the induction of adaptive immunity. We have emphasized three intricate and innate properties of DCs that account for their sentinel and sensor roles in the immune system: (1) special mechanisms for antigen capture and processing, (2) the capacity to migrate to defined sites in lymphoid organs, especially the T cell areas, to initiate immunity, and (3) their rapid differentiation or maturation in response to a variety of stimuli ranging from Toll-like receptor (TLR) ligands to many other nonmicrobial factors such as cytokines, innate lymphocytes, and immune complexes. The combination of innate defenses and innate physiological properties allows DCs to serve as a major link between innate and adaptive immunity. DCs and their subsets contribute to many subjects that are ripe for study including memory, B cell responses, mucosal immunity, tolerance, and vaccine design. DC biology should continue to be helpful in understanding pathogenesis and protection in the setting of prevalent clinical problems.
Methoxyacetic acid and ethoxyacetic acid inhibit mitochondrial function in vitro

Ethylene glycol monomethyl ether (EGME) and ethylene glycol monoethyl ether (EGEE) have recently been shown to be potent reproductive toxicants in laboratory animals. The toxicity of these compounds is believed to be due to their metabolites, methoxyacetic acid (MAA) and ethoxyacetic acid (EAA). Since the primary targets of EGME and EGEE appear to be tissues with rapidly dividing cell systems and high rates of respiration and energy metabolism, the effects of these compounds and their proposed metabolites on mitochondria were investigated. At concentrations beginning at 3.85 mM, MAA and EAA inhibited state 3 respiration and the respiratory control ratio (RCR) in hepatic mitochondria with either succinate or citrate/malate as substrates. Cytochrome c oxidase activity was also inhibited by both metabolites at similar concentrations. The effects of MAA, the metabolite from the more potent compound, on testicular mitochondria were found to be comparable. Neither EGME or EGEE appeared to affect mitochondrial function at concentrations as high as 238 or 113 mM, respectively. These results support the hypothesis that the toxicity of EGME and EGEE are due to their metabolites, MAA and EAA, and that these metabolites may exert their effects, in part, on mitochondrial function.
Presidential Address: The Endocrine Society

T PRESIDENTS of societies, in their annual orations are privileged by tradition to take stock of something or other, or to give broad, general or philosophical presentations. The membership, also by tradition, is obliged to listen to the stocktaking, or to the philosophy. So will it be today. Some time ago I became aware that many authors of scientific articles, even those appearing in prestigious journals such as Endocrinology or the Journal of Clinical Endocrinology and Metabolism were failing to mention the names of earlier workers upon whose studies their own experiments were based. This disease which can be called "failure to quote" seems to be getting worse. This realization becomes particularly upsetting when it is one's own work which had not been quoted. Everyone of you in the audience must have had this experience. To be charitable, it must be admitted that oftentimes "failure to quote" is due simply to ignorance, or to the specific instructions of editors, anxious to conserve costly space. More commonly the syndrome, "failure to quote" comes about because the mass of literature upon which one's work is based is so large, so complex, built up on detail after detail, that even with the best will, one could not unravel the thread which led to the author of the first idea, the first insight, the first concept, the first technique. One scientist I know expressed this point well when he said facetiously that for him, endocrinology began in 1972, the year he began his post-doctoral research fellowship. The advent of computer search of the literature has accentuated the problem. Programs, such as the Medlar program give only a 5 year bibliography, thus indicating, in an in-
Pomset mcfgs

This paper identifies two orthogonal dimensions of context sensitivity, the first being context sensitivity in concurrency and the second being structural context sensitivity. We present an example from natural language which seems to require both types of context sensitivity, and introduce partially ordered multisets (pomsets) mcfgs as a formalism which succintly expresses both.
Alternative Egg Collection System for Mass Production of Mediterranean Fruit Fly (Diptera: Tephritidae)

Two types of egg-collection devices for rearing Ceratitis capitata (Wiedemann) were compared for effects on egg production by adults and on egg hatch. Significantly higher efficiency was obtained from females in cages with perforated bottles than in cages with screen as oviposition sites. Consequently, a bottle oviposition cage was modified for large-scale egg production by incorporating a new egg collection method that precludes the escape of flies during egg harvest. The modified cage was equal to or better than the standard plywood cage used for the past 10 years in Hawaii. Specifications were described for a cage and operations system capable of providing 1 × 109 eggs per week.
Molecular genetics of colorectal cancer

Abstract Colorectal cancer is the end result of an accumulation of destabilizing mutations and other genetic events, which occur in clones of colonocytes over many years. While each colorectal cancer is genetically unique, there are at least three distinct mechanisms by which the process occurs. The commonest is chromosomal instability, producing microsatellite stable, aneuploid cancers. The second is DNA promoter methylation that underlies CpG island methylation phenotype cancers, either microsatellite stable or unstable, and the third is loss of DNA mismatch repair, causing microsatellite unstable, diploid cancers. Cancers arising from these three mechanisms are biologically different and the differences have clinical implications.
Properties, formulations, and algorithms for portfolio optimization using Mean-Gini criteria

We study an extended set of Mean-Gini portfolio optimization models that encompasses a general version of the mean-risk formulation, the Minimal Gini model (MinG) that minimizes Gini’s Mean Differences, and the new risk-adjusted Mean-Gini Ratio (MGR) model. We analyze the properties of the various models, prove that a performance measure based on a Risk Adjusted version of the Mean Gini Ratio (RAMGR) is coherent, and establish the equivalence between maximizing this performance measure and solving for the maximal Mean-Gini ratio. We propose a linearization approach for the fractional programming formulation of the MGR model. We also conduct a thorough evaluation of the various Mean-Gini models based on four data sets that represent combinations of bullish and bearish scenarios in the in-sample and out-of-sample phases. The performance is (i) analyzed with respect to eight return, risk, and risk-adjusted criteria, (ii) benchmarked with the S&P500 index, and (iii) compared with their Mean-Variance counterparts for varying risk aversion levels and with the Minimal CVaR and Minimal Semi-Deviation models. For the data sets used in our study, our results suggest that the various Mean-Gini models almost always result in solutions that outperform the S&P500 benchmark index with respect to the out-of-sample cumulative return. Further, particular instances of Mean-Gini models result in solutions that are as good or better (for example, MinG in bullish in-sample scenarios, and MGR in bearish out-of-sample scenarios) than the solutions obtained with their counterparts in Mean-Variance, Minimal CVaR and Minimal Semi-Deviation models.
Tissue engineering. Restoring voice.

In most mammals, a vocal sound begins with the vibration of paired vocal cords within the larynx. These delicate structures--more accurately called vocal folds because they resemble folded layers of fabric--can stiffen after traumatic injury, cancer treatment, or unknown environmental or genetic insults. Current voice medicine has limited options to repair or replace damaged vocal folds when the voice disturbance is disabling (1). A recent study by Ling et al. (2) reports a tissue engineering approach that could lead to implants that replace the unique vocal fold mucosa and restore vocalization.
Live Load Effects in Office Buildings

Fractiles of office building live load effects deduced from a combination of recent statistical data and probabilistic models are compared with popular code recommendations for design loads and areal reduction factors. The effects of loaded area, shape of influence surface, and division into independently acting tenants are studied systematically. The conventional definition of tributary area is not the most satisfactory one available. Several alternative forms of code presentation of design loads are compared, including a naive but accurate probabilistic model.