cssi/SciSciGPT-SciSciNet huggingface dataset:
A nationwide analysis of pancreatic cancer trial enrollment reveals disparities and participation problems.

Abstract Background Our research group recently surveyed the clinical trial landscape in pancreatic adenocarcinoma and identified 430 active trials. These represent an opportunity to expand treatment options for patients with pancreatic adenocarcinoma. Our primary objective was to detail clinical trial participation among patients with pancreatic adenocarcinoma. Our secondary objective was to evaluate survival. Methods We queried the National Cancer Database (2004–2016) for patients with pancreatic adenocarcinoma. Patients were stratified by trial participation: clinical trial or non-trial. Multivariable logistic regression was used to identify variables associated with trial participation. The Kaplan-Meier method and multivariable Cox hazards regression were used to analyze survival. Results In total, 261,483 patients were included: 1,110 (0.4%) were enrolled in a clinical trial. A total of 57 Black patients participated in a clinical trial (0.19% of Black patients). This was lower compared to White patients (n = 955, 0.49% of White patients, P Trial participation was associated with an increased median survival relative to non-trial patients (stage IV: 9.0 vs 3.8 months, P Conclusion Fewer than 1% of patients with pancreatic adenocarcinoma participated in a clinical trial. There are racial and sociodemographic disparities in clinical trial enrollment. An association was observed between clinical trial participants and prolonged survival.
Anesthetic modulation of pulmonary vascular regulation.

Publisher Summary Anesthetic agents have the potential to alter pulmonary vasomotor tone directly, or to modify the complex array of vasoactive mechanisms that regulate the pulmonary circulation. This chapter summarizes some of the researches concerning anesthetic modulation of pulmonary vascular regulation in chronically instrumented dogs. The results provide compelling evidence that general anesthesia can alter neural, hymoral, and local mechanisms of pulmonary vascular regulation. It has been documented that regulation of the pulmonary vascular P/Q relationship is multifactorial, and that these vascular mechanisms are interactive. These results in conscious animals serve as a database to assess the specific effects of general anesthesia on pulmonary vascular regulation. It has been found that different anesthetics can have differential effects on neural, humoral, and local mechanisms of pulmonary vascular regulation. Halothane causes active pulmonary vasoconstriction that is not attenuated by sympathetic α 1 -adrenoreceptor block, angiotensin-converting enzyme inhibition, combined arginine vasopressin V 1 and V 2 receptor block, or by cyclooxygenase inhibition. Isoflurane is a rapid-onset inhalational anesthetic that is frequently used for surgical procedures that require controlled hypotension to minimize bleeding. In contrast to halothane, isoflurane has no net effect on the baseline P/Q relationship. Without this fundamental information, it is difficult to interpret previous experimental studies that have utilized background anesthetics. Moreover, this information is essential for the adequate clinical management of patients in the perioperative period. These in vivo studies have allowed identifying the overall effects of general anesthetics on the integrative response of the intact organism to these diverse pulmonary vasoregulatory pathways.
Taste predicates and the acquaintance inference

Simple sentences containing predicates like "tasty and "beautiful" typically suggest that the speaker has first-hand knowledge of the item being evaluated. I consider two explanations of this "acquaintance inference": a presuppositional approach, and a pragmatic-epistemic approach. The presuppositional approach has a number of virtues, but runs into trouble because the acquaintance inference has a very different projection pattern from that of standard presuppositions. The pragmatic-epistemic approach accounts for the main data discussed in the paper, but faces challenges of its own.
Phosphatidylinositol-linked glycans and phosphatidylinositol-anchored proteins of Tetrahymena mimbres.

The insoluble residue from Tetrahymena mimbres cells that had been preincubated in vivo for 2 h with [3H]myristic acid and then exhaustively delipidated with organic solvents retained radioactivity, principally in material which migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular mass of 10-14 kDa. This material was extractable from the delipidated cell residue with organic solvents known to solubilize phosphatidylinositol glycans (PI glycans). The same material could also be labeled with [3H]inositol, [14C]glucosamine, and [3H] ethanolamine. When the delipidated residue of cells labeled for 2 h with [3H]myristate was treated with phosphatidylinositol-specific phospholipase C or nitrous acid, much of the associated radioactivity was released. A similar release was obtained using the putative PI glycan fraction extracted from the cell residue. After further purification by thin layer chromatography, this latter material was hydrolyzed with HCl and shown to contain fatty acids, alkylglyceryl ethers, phosphate, inositol, glucosamine, mannose, and ethanolamine. The findings indicate that T. mimbres contains PI glycans resembling in structure those recently characterized in trypanosomes and mammalian cells. As the time of incubation with the radiotracers enumerated above was increased to 6-24 h, increasing amounts of radioactivity appeared in the 22-27-kDa region of sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels. This higher molecular weight material is shown in the companion paper (Pak, Y., Ryals, P.E., and Thompson, G.A., Jr. (1991) J. Biol. Chem. 266, 15054-15059) to be released by in vivo phosphatidylinositol-specific phospholipase C treatment. Thus T. mimbres contains a pool of free PI glycans and at least one phosphatidylinositol-anchored protein.
A scalable multicast service for mesh networks

The authors investigate the scalability of a multicast algorithm designed for wormhole-routed mesh networks. The algorithm, known as the U-mesh algorithm, is shown to scale well in four ways: with the dimension of the mesh, with the number of destinations, with the system size, and with the problem size. It is demonstrated that the only factor that affects the multicast latency is the number of destinations and that, for a given number of destinations, the number of time steps required to perform a multicast operation is minimal. Performance measurements of implementations on a 64-node nCUBE-2 and a 168-node Symult 2010 are given. >
Barriers to Care and Psychological Distress Differences between Bisexual and Gay Men and Women

The bisexual community may face unique barriers to health care that affect mental health outcomes; however, previous research has not specifically compared bisexual and gay men and women on these factors. This study explored differences between bisexual and gay men and women in barriers to care and psychological distress among a sample of 2,500 bisexual and gay men and women recruited online. Bisexual men and women were more likely to report barriers to care ranging from limited availability of providers to less comfort discussing their sexual orientation with their provider. Differences in specific mental health outcomes centered on sexual orientation, but not gender. Bisexual women reported the highest levels of depression, stress, and anxiety, and bisexual men reported higher levels of anxiety than gay men and gay women. Findings suggest that the sociocultural pressures affecting barriers to care and psychological distress may be disproportionately affecting bisexual individuals, even more so than prev...
Identification of amino acid residues of the Agrobacterium tumefaciens quorum‐sensing regulator TraR that are critical for positive control of transcription

Summary The LuxR-type quorum-sensing transcription factor TraR regulates replication and conjugal transfer of the tumour-inducing (Ti) plasmid in the plant pathogen Agrobacterium tumefaciens. TraR is a two-domain protein with an N-terminal domain that binds to the quorum-sensing signal N-3-oxooctanoyl- l-homoserine lactone (OOHL) and a C-terminal domain that binds to specific DNA sequences called tra boxes. TraR–OOHL complexes form homodimers that activate transcription of at least seven promoters on the Ti plasmid. At five promoters, a tra box overlaps the binding site of core RNA polymerase (class II promoters), while in the other two promoters, this site is located farther upstream (class I promoters). In this study, we performed saturating point mutagenesis of the surface residues of the TraR C-terminal domain. Each mutant was tested for proteolytic stability and transcription activity in vivo, and for DNA binding activity in vitro. Mutants of TraR with single substitutions at positions W184, V187, K189, E193Q, V197 and D217 have wild-type levels of accumulation and DNA binding, but are defective in transcription of both types of promoters. These residues constitute a patch on the surface of the DNA-binding domain. We propose that this patch is an activating region that recruits RNA polymerase to TraR-dependent promoters through direct contact. As residues of this patch are critical for activation at both a class I and a class II promoter, we predict that these residues may contact the C-terminal domain of the RNA polymerase α-subunit.
QUANTITATIVE ANALYSIS OF REGIONAL VARIABILITY IN THE DISTRIBUTION OF TRANSVERSE TUBULES IN RABBIT MYOCARDIUM

The goal of the present investigation was to compare quantitatively the distribution of T-tubules between regions of the myocardium. The volume fraction and surface density of T-tubules in rabbit right atrial free wall, left atrial free wall, right ventricular free wall, left ventricular free wall, right ventricular papillary muscle, and left ventricular papillary muscle were measured using established, electron-microscopic, morphometric techniques. T-tubules were delineated using wheat-germ agglutinin conjugated to horseradish peroxidase as a tracer. No significant differences were found in the morphometric parameters between any two ventricular samples or between atrial samples. Furthermore, little difference between T-tubule volume fraction or surface density was found between individual animals for any given site. Both volume fraction and surface density of ventricular T-tubules were more than ten-times their values in atrial tissue (volume fraction: 3.43%±0.35 vs. 0.20±0.09; surface density: 2.46 μm2/μm3±0.11 vs 0.10±0.04). Measurements show that there is greater variation of T-tubule volume fraction and surface density within atrial samples than within ventricular samples. This suggests greater inhomogeneity in T-tubule distribution in atrial myocardium than in ventricular myocardium. Morphometric data also indicate that the mean diameter of atrial T-tubules is greater than that of ventricular T-tubules while qualitative observations show that atrial T-tubules are distributed less regularly and have a larger longitudinal component to their organization than those in the ventricular myocardium.
Code analysis and parallelizing vector operations in R

This paper presents some current work and preliminary thoughts on two seemingly unrelated areas. The first is the development of code analysis tools to help identify possible errors in R code. Current versions of these tools have been useful in finding bugs in R’s code as well as code in packages submitted to CRAN. The second area, where work is just beginning, is the development of mechanisms to allow R’s internal vectorized operations, as well as vectorized operations defined in packages, to take advantage of multiple processors. These two areas are related through their connections to ongoing efforts to develop a byte code compiler for R.
Long-term mechanical and viscoelastic behavior of constitutive polymeric materials used for magnetic tapes

Creep-compliance behavior of specially prepared magnetic tape materials was measured at elevated temperature levels to facilitate the use of a time–temperature superposition (TTS) process. This TTS process allowed for the construction of master curves at a reference temperature of 30°C, which were used to predict the long-term viscoelastic behavior of the magnetic particle (MP) and metal-evaporated (ME) tapes used in the study. The specially prepared samples allowed for the use of a rule of mixtures technique to determine the long-term creep compliance of the front coat and back coat used for the magnetic tapes. To test the validity of this procedure, the front coat, substrate, and back coat data determined through separate experiments were used to calculate creep compliances of simulated tapes. These calculated creep-compliance curves were then compared to measured data for the actual magnetic tapes. After determination and validation of the front coat, substrate, and back coat creep-compliance data sets, they were used to determine strain distributions when the tapes are stored in a reel. Strain distributions were calculated for two cases, which reflect how tapes are stored in different drives: (1) the front coat (magnetic + nonmagnetic layer) is oriented away from the hub, and (2) the front coat is oriented toward the hub. Results showed that strain in the critical front coat of a tape is lower if it is stored with the front coat oriented toward the hub. In addition, the use of the creep-compliance data showed that the MP tape front coat is more susceptible to creep than the ME tape front coat. The strain distributions in future magnetic tapes were also simulated by reducing the thickness and compliance of the layers. Results showed the importance of using lower compliance front coat, substrate, and back coat materials if thinner tapes are to be developed to increase the volume of information that can be stored in a magnetic tape reel. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1142–1160, 2001
Relaxation-time approximation for sound attenuation in superfluid He 3

The sound attenuation due to collisions in superfluid $^{3}\mathrm{He}$ is studied, using for the collision integral a simplifying ansatz which satisfies conservation laws. In the zero-sound regime, attenuation and velocity are fairly frequency independent; this supports the idea that collisions can be accounted by a mere background in sound attenuation. In the first-sound regime, the viscosity tensor is studied (in the $A$ phase) and its low-temperature behavior investigated.
Attitude control with realization of linear error dynamics

An attitude control law is derived to realize linear unforced error dynamics with the attitude error defined in terms of rotation group algebra (rather than vector algebra). Euler parameters are used in the rotational dynamics model because they are globally nonsingular, but only the minimal three Euler parameters are used in the error dynamics model because they have no nonlinear mathematical constraints to prevent the realization of linear error dynamics. The control law is singular only when the attitude error angle is exactly pi rad about any eigenaxis, and a simple intuitive modification at the singularity allows the control law to be used globally. The forced error dynamics are nonlinear but stable. Numerical simulation tests show that the control law performs robustly for both initial attitude acquisition and attitude control.
The combination of insulin‐like growth factor 1 and osteogenic protein 1 promotes increased survival of and matrix synthesis by normal and osteoarthritic human articular chondrocytes

Objective Although growth factor therapy could be an attractive method for stimulating the repair of damaged cartilage matrix, there is evidence that with aging and/or with the development of osteoarthritis (OA), articular chondrocytes may become unresponsive to growth factor stimulation. The aim of the current study was to compare the ability of insulin-like growth factor+(IGF-1) and osteogenic protein+(OP-1), alone and in combination, to stimulate human normal and OA chondrocytes in culture. Methods Chondrocytes isolated by enzymatic digestion of cartilage obtained from subjects undergoing knee replacement for OA (n = 6) or from normal ankle joints of tissue donors (n = 7) were cultured in alginate beads in serum-free medium and treated for 21 days with 100 ng/ml IGF-1, 100 ng/ml OP-1, or both. Controls were treated with vehicle alone. The cultures were evaluated for cell survival, cell number by DNA analysis, matrix production by particle exclusion assay, and level of accumulated proteoglycan by dimethylmethylene blue assay. Results After 21 days in serum-free alginate culture, survival of cells from OA cartilage was 65 ± 2% (mean ± SEM), while survival of cells from normal cartilage was significantly greater (82 ± 3%). Treatment with either IGF-1 or OP-1 alone minimally improved survival, while the combination IGF +OP significantly improved survival, to 87 ± 2% for OA cells and 95±1% for normal cells. Cell proliferation was noted only in the IGF+OP group; this was significant for both normal and OA cells (∼2-fold increase in DNA levels). Matrix production, assessed by particle exclusion and by proteoglycan accumulation, was greatest in the cells treated with IGF + OP in both normal and OA cultures. When proteoglycan levels were corrected for cell numbers (mg proteoglycan/ng DNA), a significant increase over control was noted with OP-1 alone and IGF IGF-1 alone, in both normal and OA cultures, with the greatest levels in the combination group (3-fold increase over control). Conclusion OP-1 was more potent than IGF-1 in stimulating proteoglycan production in both normal and OA cells. However, the best results were obtained with the combination, suggesting that combined therapy with IGF-1 and OP-1 may be an effective strategy for treating OA cartilage damage.
Botulinum Toxin: Mechanism of Presynaptic Blockade

The mechanism of action of botulinum toxin was analyzed by the use of calcium ionophores and black widow spider venom. Addition of calcium ionophores to nerve-muscle preparations blocked by botulinum toxin did not increase the frequency of miniature end plate potentials. However, the spider venom elicited a barrage of miniature end plate potentials after blockade by botulinum. Electron micrographs of preparations treated with botulinum toxin and then the spider venom revealed clumping of synaptic vesicles at release sites in the otherwise depleted nerve terminals. These findings indicate that the action of botulinum toxin is not due to deficient storage of acetylcholine in vesicles or blockade of calcium entry into nerve terminals. They suggest that the toxin interferes with the acetylcholine release process itself, possibly by blocking exocytosis at the release sites.
The melanocortin 5 receptor is expressed in human sebaceous glands and rat preputial cells.

Melanocortins regulate pigmentation, adrenal hormone secretion, immune functions, lipid metabolism, and feeding behaviors in rodents. These peptides include adrenocorticotrophic hormone, melanocyte stimulating hormone, β-lipotrophin, and the endorphins. Lipid metabolism in sebaceous glands and preputial glands of rodents is regulated by α-melanocyte stimulating hormone, the major agonist for melanocortin receptors. Five melanocortin receptor subtypes have been identified that differ in their tissue localization and affinities for melanocortin ligands. Targeted disruption of the melanocortin 5 receptor in transgenic mice results in widespread dysfunction of exocrine glands, including a marked decrease in sebum production. A role for melanocortins in the modulation of human sebum production has not been established. The goal of this study is to determine which melanocortin receptors are expressed in human sebaceous glands. Messenger RNA was isolated from human sebaceous glands and the reverse transcriptase polymerase chain reaction was performed using primers specific for each of the melanocortin receptor subtypes. Transcripts were detected for the melanocortin 5 receptor. A polyclonal chicken antihuman antibody to the melanocortin 5 receptor localized to sebaceous glands, eccrine glands, hair follicles, and epidermis in human skin, rat skin, cultured human sebocytes, and rat preputial cells. Presence of the melanocortin 5 receptor protein in human sebaceous glands and rat preputial glands was further verified by Western blotting. These data support further investigation of the role of melanocortins in the regulation of human sebum production and support the use of the rat preputial system as an experimental model in sebaceous gland physiology.
Measuring Engagement in Video Games: A Questionnaire:

Video games continue to grown in popularity and presently account for annual revenues in the billions of dollars. Although the technologies underlying a modern video game are well understood, the c...
Gonadal morphology of the weedy seadragon, Phyllopteryx taeniolatus (Lacépède): characterisation of ovarian and testicular maturation

Because little is known about the reproductive biology of the weedy seadragon, Phyllopteryx taeniolatus, we sought to characterise for the first time the morphology and histology of the gonads of female and male weedy seadragons. Each seadragon ovary consisted of a pair of cylindrical tubes with a total of four tubes per female with follicles arranged with less mature oocytes originating from the germinal ridge and progressively more advanced oocytes occurring in a spiral fashion around the periphery of less-developed oocytes. Seadragon testes had a system of interconnecting seminiferous tubules with spermatocyte development occurring within the tubule. Spermatocytes were observed along the testis wall and appeared to emerge into the lumen where further development of spermatocytes occurred. This study represents the first examination of the gonadal structures of the weedy seadragon, a species currently classified by the International Union for Conservation of Nature (IUCN) as ‘Near Threatened’. The descriptions of morphological development of the gonads may be useful in the histological identification of the stages of gametogenesis and reproductive status of other syngnathids. In addition, this information may also provide useful information in elucidating the phylogeny of this family of fishes.
Validation of Bateman's principles: a genetic study of sexual selection and mating patterns in the rough–skinned newt

Few studies have ine uenced thought on the nature of sexual selection to the extent of the classic paper of A. J. Bateman on mating patterns in Drosophila. However, interpretation of his study remains controversial, and a lack of modern empirical evidence prevents a consensus with respect to the perceived utility of Bateman’ s principles in the study of sexual selection. Here, we use a genetic study of natural mating patterns in the rough-skinned newt, Taricha granulosa , to investigate the concordance between Bateman’ s principles and the intensity of sexual selection. We found that males experienced strong sexual selection on tail height and body size, while sexual selection was undetectable in females. This direct quantie cation of sexual selection agreed perfectly with inferences that are based on Bateman’ s principles. Specie cally, males (in comparison with females) exhibited greater standardized variances in reproductive and mating success, as well as a stronger relationship between mating success and reproductive success. Overall, our results illustrate that Bateman’ s principles provide the only quantitative measures of the mating system with explicit connections to formal selection theory and should be the central focus of studies of mating patterns in natural populations.
Lithospheric evolution in the wake of the Mendocino Triple Junction: structure of the San Andreas Fault system at 2 Ma

As the Mendocino triple junction (MTJ) moves northwards up the North American margin, the tectonic regime changes from subduction to strike-slip. For the first few million years following triple junction migration, the San Andreas Fault system consists of several strike-slip faults distributing deformation over a region ~ 150 km wide. This same region is expected to be affected by a slab gap beneath North America, created by the northward removal of the subducting Gorda plate, and into which asthenospheric mantle is thought to rise to crustal depths. The onshore and offshore Mendocino Triple Junction Seismic Experiment (MTJSE) provides a continuous seismic velocity-reflectivity cross-section across the deforming zone from the Pacific ocean basin to the eastern edge of the California Coast Ranges. The accretionary complex rocks that make up most of the crustal thickness are underlain by a 5-10 km thick high-velocity(6.4-7.2 km s- 1) layer at the base of the crust that extends from the Pacific to at least 50 km, and probably 90 km east of the San Andreas Fault. The top of the lower crustal layer deepens from 7 km beneath the Pacific ocean basin at the west end of the profile to 23 km at the east end by a gentle (5° -10°) eastward dip punctuated by abrupt offsets at the San Andreas and Maacama fault zones. At each fault the top of the lower crust is offset by up to 4 km, down to the east. The Moho is similarly deformed beneath the faults, although by only 2 km. Such localized deformation of the Moho implies that these two strike-slip faults penetrate through the entire crust to the upper mantle. Good agreement between seismic velocity and seismic reflectivity in the vicinity of the faults gives confidence in these results, although details of the offset beneath the San Andreas Fault are better resolved than those under the Maacama Fault. Seismic velocities in the upper mantle show only a small change along the profile, from 8.1 km s- 1 beneath the Pacific to about 7.9 km s- 1 beneath the Coast Ranges. We infer that upwelling of asthenosphere into the slab gap is limited laterally, or a lithospheric lid is present in the slab gap by 2 Ma. Gravity data and crustal density structure show that most of the margin width is in local Airy isostasy with the changes in crustal thickness near the strike-slip faults corresponding closely to changes in surface topography. The crustal blocks defined by the strike-slip faults appear to be independently in isostatic equilibrium, provided that the mantle beneath the Coast Ranges has a somewhat lower density than that beneath the Pacific plate. The densities in the Coast Range upper mantle are consistent with limited temperature elevation, suggesting that the asthenospheric mantle is present beneath the depth of seismic energy penetration from our survey.
Place learning by mechanical contact

For some animals (e.g. the night-active wandering spider) the encounters with the habitat that result in place learning are predominantly mechanical. We asked whether place learning limited to mechanical contact, like place learning in general, entails vectors tied to individual landmarks and relations between landmarks. We constructed minimal environments for blindfolded human participants. Landmarks were raised steps. 'Home' was a mechanically indistinct location. Travel was linear. The mechanical contacts were those of walking, stepping, and probing with a soft-tipped cane. Home-orienting activities preceded tests of finding home from a given location with landmarks unchanged or (unbeknown to participants) shifted. In a one-landmark environment, perceived home shifted in the same direction, with the same magnitude, as the shifted landmark. In an environment of two landmarks located in the same direction from home, shifting the further landmark toward home resulted in a change in home's perceived location that preserved the original ratio of distances separating home, nearer landmark, and further landmark. Both findings were invariant over the travel route to the test location and repetitions of testing. It seems, therefore, that for humans (and, perhaps, for wandering spiders), mechanical contact can reveal the vectors and relations specifying places.
Partial deficiency of erythrocyte spectrin in hereditary spherocytosis

Hereditary spherocytosis (HS) is a common, clinically heterogeneous haemolytic anaemia in which the primary erythrocyte defect is believed to be some abnormality in the spectrin-actin membrane skeleton, leading to loss of surface membrane. Recessively inherited spectrin deficiency with extreme erythrocyte fragility and spherocytosis has been identified in certain mutant mice and two severely anaemic humans. Although suspected, deficiency of spectrin has not been demonstrated in less severe forms of human HS. We not report the quantitation of erythrocytes spectrin by radioimmunoassay. We found that normal erythrocytes contained 240,000 copies of spectrin heterodimer, whereas erythrocytes from 14 patients with a variety of types of HS were all partially deficient in spectrin (range 74,000-200,000 copies), the magnitude of the deficiency correlating with the severity of the disease. Spectrin deficiency of varying degrees is common in HS and probably represents the principal structural defect leading to loss of surface membrane.
Agricultural Economics, Contributions: Discussion

It is a great pleasure and an honor to participate in this joint AAEA-AEA session. I gave my first paper at a professional association at just such a joint session here in New York City on a Saturday morning at the end of December 1955, so this occasion represents something of a "homecoming" for me. In any case, I make my remarks as "a member of the family" and hope they will be accepted as such despite my long absence. My charge is to discuss the papers by Fox and Stan Johnson, but the thoughtful remarks of Houck are too important and come so close to stating my theme that I hope Meyers and Gale Johnson will forgive my spreading out a bit. Let me begin by stating some general principles: Science deals with reality, in contrast, perhaps, to poetry and music and mathematics. As scientists, we are concerned with understanding the real world and in controlling or modifying it. As social scientists, we are concerned with human behavior and institutions and with how individuals interact with one another in a social environment. As economists, we are concerned preeminently with optimizing behavior, allocation of scarce resources to multiple ends, and with the way in which individual agents interact within the framework of markets or other economic institutions. As agricultural economists, we are concerned with the reality of agriculture, with the way in which economic agents in agriculture behave given the biological and environmental constraints which they face, with how they interact with one another and with economic agents outside the agricultural sector, and with the modification of institutions and policies, both within and without agriculture. Concern with economic theory or with quantitative methods or tools is a means, and only a means, to this end. A ademic disciplines, in contrast to science, deal with a series of internally generated problems and proceed with a certain internal momentum only partly motivated by a desire to better understand and control the real world. Economics and agricultural economics are no exception to this rule. The sad truth is that the majority of both our professions, economics and agricultural economics, is more concerned with what a half dozen or a dozen
The synthesis and structural characterization of Zr3(S)(ButS)10. A Zr–S cluster that contains thiolate ligands in three different modes of co-ordination

The synthesis and structural (crystallographic and spectroscopic) characterization of the new Zr3(S)(ButS)10 cluster is described.
Treatment response to transcatheter arterial embolization and chemoembolization in primary and metastatic tumors of the liver

Introduction. Transcatheter arterial embolization (TAE) and chemoembolization (TACE) are increasingly used to treat unresectable primary and metastatic liver tumors. The purpose of this study was to determine the objective response to TAE and TACE in unresectable hepatic malignancies and to identify clinicopathologic predictors of response. Materials and methods. Seventy-nine consecutive patients who underwent 119 TAE/TACE procedures between 1998 and 2006 were reviewed. The change in maximal diameter of 121 evaluable lesions in 56 patients was calculated from pre and post-procedure imaging. Response rates were determined using Response Evaluation Criteria in Solid Tumors (RECIST) guidelines. The Kaplan-Meier method was used to compare survival in responders vs. non-responders and in primary vs. metastatic histologies. Results. TAE and TACE resulted in a mean decrease in lesion size of 10.3%±1.9% (p<0.001). TACE (vs. TAE) and carcinoid tumors were associated with a greater response (p<0.05). Lesion response was not predicted by pre-treatment size, vascularity, or histology. The RECIST partial response (PR) rate was 12.3% and all partial responders were in the TACE group. Neuroendocrine tumors, and specifically carcinoid lesions, had a significantly greater PR rate (p<0.05). Overall survival, however, was not associated with histology or radiologic response. Discussion. TAE and TACE produce a significant objective treatment response by RECIST criteria. Response is greatest in neuroendocrine tumors and is independent of vascularity and lesion size. TACE appears to be superior to TAE. Although an association of response with improved survival was not demonstrated, large cohort studies are necessary to further define this relationship.
Anionic copolymerization of styrene and 1,1‐diphenylethylene

Kinetics of anionic copolymerization of styrene (S) and 1,1-diphenylethylene (D) were investigated in THF. The rate constant of addition of D to living polystyrene was found to be k1,2 ± = 250 l./mole-sec. for , Na+ ion-pair, and that for the free , Na+ ion is k1,2−∼400,000 l./mole-sec. Both values refer to 25°C. The addition of styrene to D−, Na+ was found to be reversible: and k2,1 was determined by three different methods to be ∼0.5–0.7 l./mole-sec. Studies performed in a stirred-flow reactor led to k-21 = 13 sec. −1 and K21 ∼ 5 × 10−2 l./mole. An alternating copolymer is obtained in the presence of a large excess of 1,1-diphenylethylene.
Magnetoconductivity tensor of a two dimensional plasma in quantizing magnetic field

Abstract The nonlocal dynamic magnetoconductivity tensor σ i j of a two dimensional plasma subject to Landau quantization is obtained using the R.P.A.: σ i j is presented here in closed form and also in a “Landau series” expansion valid for all magnetic fields.
The status of the DØ silicon tracker upgrade project

Abstract The current status of the silicon tracker for the DO upgrade project for Run II at the Tevatron is presented. After reviewing the design considerations the status of delivery and testing of the different silicon sensors is presented. The ladder production and assembly process is also discussed.
Partitioning of even networks for improved diagnosability (multiprocessor systems)

A partitioning property of even interconnection networks is presented. This property is based on the Hadamard matrix combinatorial structure which is used to partition the network into identical spheres. A semidistributed diagnosis algorithm helps to identify faulty components (nodes/links) in each sphere. Using the diagnosis result of each sphere on a global level, the overall diagnosability or even networks is improved drastically over previous results. This partitioning and diagnosis scheme can be used for almost any network that has some group-theoretic representation, including the binary hypercube. >
“Juntos pero no revueltos”: microaggressions and language in the mathematics education of non-dominant Latinas/os

In this paper, we discuss the characteristics of microaggressions based on minority language(s) as a form of discriminatory practice against non-dominant students in the mathematics context. Microaggressions are subtle, brief, and commonplace verbal, behavioral, or visual negative slights or insults toward people of color. We extend the concept of microaggression to include discrimination based on a minority language. We draw on our work with Latinas/os in the USA to demonstrate the occurrence of microaggressions in the teaching act. Revealing microaggressions based on language has the potential of creating more equitable learning environments for non-dominant students and can point to possible directions for future research and improvements in the preparation of teachers who serve non-dominant students who speak a language other than the school’s official language.
Partitioning behavior of group 1 and 2 cations in poly(ethylene glycol)-based aqueous biphasic systems

Abstract The partitioning behavior of several Group 1 and 2 cations was investigated in poly(ethylene glycol) (PEG)-based aqueous biphasic systems. All of these metal ions prefer the salt-rich phase over the PEG-rich phase with distribution ratios all well below one regardless of the system investigated. The relative salting-out ability of the individual cations can be directly correlated to their Gibbs free energy of hydration (ΔGhyd). In addition, the relative magnitude of the distribution ratios for these metal ions can also be explained in terms of ΔGhyd.
2,3,7,8-Tetrachlorodibenzo-p-dioxin Induction of Cytochrome P450-Dependent Arachidonic Acid Metabolism in Mouse Liver Microsomes: Evidence for Species-Specific Differences in Responses

Arachidonic acid is biotransformed to metabolites active in signal transduction by cytochrome P450 (CYP) as well as by cyclooxygenase and lipoxygenase enzymes. Inducers of CYP1 enzymes, including 2,3,7,8-tetrachlorodibenzo-p-dioxin and other Ah receptor ligands, markedly increase liver microsomal CYP-dependent arachidonic acid epoxygenation in chicks but depress epoxygenation in rat liver microsomes where they elicit about twofold increases in formation of other CYP products, omega-1 to omega-4-OH arachidonic acid. These studies examined the effect of TCDD on metabolism of [1-14C]-labeled arachidonic acid by mouse liver microsomes. Mouse liver microsomes metabolized arachidonic acid exclusively by a CYP-dependent mechanism as evidenced by lack of metabolism in the absence of NADPH and by formation of specific CYP-dependent metabolites. The major constitutive products were epoxygenase products (EETs and EET-diols) and omega-OH arachidonic acid. Treatment with TCDD increased formation of omega-2- to omega-4-OH arachidonic acid products 23-fold, formation of omega-1-OH arachidonic acid about 5-fold, and formation of epoxygenase products and HETEs each about twofold. In contrast, TCDD treatment decreased formation of omega-OH arachidonic acid by over 70%. EET-diols comprised a greater fraction of total epoxygenase products in mouse liver microsomes than has been found for liver microsomes of other species. The high EET-diol formation was attributable to a non-TCDD-inducible, EET epoxide hydrolase activity in mouse liver microsomes. For comparison, the effect of TCDD on [1-14C]-labeled arachidonic acid was examined in homogenates of spleen, an immune system target of TCDD. While levels of total [1-14C]-arachidonic acid metabolism were comparable in both tissues, virtually all of the metabolism by spleen was CYP-independent, and it was unaffected by TCDD. Western blotting experiments showed that TCDD-induced mouse Cyp1a1 and 1a2 share immunologic epitopes with chick CYP1A4 and 1A5. However, in immunoinhibition studies, an antibody to CYP1A5, the chick arachidonate epoxygenase, was ineffective against TCDD-induced arachidonic acid metabolism in mouse liver microsomes, suggesting that there are differences in the catalytic sites or tertiary structures of CYP1A5 and the CYP-enzyme catalyzing the TCDD-induced arachidonic acid metabolism in mouse liver. This study shows that the effects of TCDD of the profile of CYP-dependent arachidonic acid metabolities and the amounts produced in mouse liver microsomes differ from other species. The findings suggest that species differences in CYP1A catalytic activities including the metabolism of arachidonic acid may contribute to species differences in sensitivity to TCDD toxicity.
Preparation of a water soluble polyester surfactant and its use in the emulsion polymerization of styrene

The synthesis procedure of Chen and Liu (1) was used to prepare a polyester surfactant from dimethyl 5-sulfoisophthalate, sodium salt, polyoxyethylene (MW 200) and phthalic anhydride by a two step esterification process. The surfactant has the unique structural features of multiple ionic groups and polyoxyethylene chains for hydrophilicity and aromatic ester linkages for hydrophobicity. The polyester surfactant exhibited a CMC of 0.25% (w/v) and a surface tension lowering of 23 dynes/cm. The use of the surfactant as stabilizer for the emulsion polymerization of styrene produced some unusual results. While the rate of polymerization was independent of surfactant concentration, the number of particles increased as N ∝ [S]0.91. The molecular weight of polystyrene produced was low and found not to be a function of surfactant concentration. The structural features of the surfactant suggest that a depletion stabilization mechanism might be operative in this system.
What We Know About Relationships That Develop Between Cooperating And Student Teachers

The student teaching practicum is a significant part of the foreign language teacher education program and as such deserves focused attention. In this article we examine six different role relationships that developed between a cohort of cooperating and student teachers of high school Spanish during a ten-week student teaching practicum. We discuss two dimensions of these relationships that were significant to their development, complementarity and reciprocity, and conclude that student teachers who formed reciprocal relationships perceived their cooperating teachers and practicum experiences more positively than those who formed only complementary relationships. We discuss the role that the university supervisors might have played in the development of these relationships and conclude by suggesting how this study might help other foreign language teacher education programs.
Effect of dietary fat intake on total body and white blood cell fat oxidation in exercised sedentary subjects

The effect of fat intake on total body (TB) and white blood cell (WBC) fat oxidation (FO) was studied during exercise in sedentary subjects. Four men and 6 women consumed diets of 19% and 50% energy from fat for 3 weeks each compared with their regular diet (30%). Before and after each diet, TB FO was measured at each stage of a treadmill test and WBC FO was determined. Fat intake had no effect on TB and WBC FO. Total body FO decreased as exercise intensity increased. WBC FO decreased postexercise as a result of an increase in WBC count. Total body FO in sedentary subjects was not influenced by diet at rest or during exercise. There was no effect from diet but exercise had a small effect on WBC FO. WBC FO may indicate a genetic predisposition for FO.
Calcification of Aortic Valve leaflets is Shear Dependent and Side-specific

Abstract Aortic valve (AV) sclerosis is a degenerative disease and is one of the leading causes of mortality in elderly population. AV experiences various mechanical stimuli such as pressure, shear and flexure with differing magnitudes on either sides of AV (fibrosa and ventricularis) with fibrosa side facing more dynamic environment. Normal hemodynamic conditions constantly renew and remodel the valve, whereas altered mechanical loading such as hypertension and altered shear stress can cause tissue inflammation that leads to calcification, preferentially on fibrosa side. AV calcification progressively leads to sclerosis and ultimately results in valve failure. However, the molecular and cellular processes that lead to inflammation and calcification are not very well understood. To understand the role of mechanics and underlying molecular mechanisms behind this preferential calcification, aortic side and ventricularis side of fresh porcine AVs were exposed to different shear stress patterns using an ex vi...
Hospital utilization and elective surgery on the Navajo Indian reservation.

Abstract A population-based patient origin study was undertaken to examine patterns and rates of hospital utilization and elective surgery in the Navajo Indian Reservation population for Fiscal Year 1973. In addition to providing material of a purely descriptive nature, the study tests the hypothesis that differences in utilization within the Navajo population are better explained by access to, rather than need for, care. Five common population measures, dependency ratio, fertility ratio, neonatal mortality, postneonatal mortality, and infant mortality are used as indices which reflect underlying need for health care in a population. Access to in-patient care is measured by average road distance travelled from each service unit as a whole to the nearest hospital. Availability of in-patient resources is measured by the number of acute-care hospital beds and full-time-equivalent physicians within each service unit. Results indicate that Navajo patterns of morbidity differ from those of the larger society. In spite of differences in morbidity patterns, Navajos behave much the same as other populations cared for under other systems in regard to hospital utilization: the more accessible the facility, the greater the utilization and the higher the rates of surgery. Indeed, ease of access rather than need for care is important in explaining much utilization behavior in this “traditional” society.
Intestinal absorption and metabolism of carotenoids: insights from cell culture

Cell culture models are useful for studying intestinal absorption and metabolism of carotenoids. The human intestinal cell line, Caco-2, has been the most widely used model for these studies. The PF11 and TC7 clones of Caco-2 exhibit beta-carotene-15,15'-oxygenase activity, a key enzyme in the conversion of carotenoids to vitamin A. Studies on the recent cloning of this enzyme are discussed. An in vitro cell culture system used to study intestinal absorption of carotenoids is presented. Under conditions mimicking the postprandial state, Caco-2 cells on membranes take up carotenoids and secrete them incorporated into chylomicrons. Both the cellular uptake and secretion of beta-carotene are saturable, concentration-dependent processes. The selective absorption of all-trans beta-carotene versus its cis isomers, the differential absorption of individual carotenoids, and the specific interactions between carotenoids during their absorption are discussed. The participation of a specific epithelial transporter in the intestinal absorption of carotenoids is proposed.
Testing for a Unit Root in Time Series With Pretest Data-Based Model Selection

In this article we examine the impact of data-based lag-length estimation on the behavior of the augmented Dickey–Fuller (ADF) test for a unit root. We derive conditions under which the ADF test converges to the distribution tabulated by Dickey and Fuller and verify that these conditions are satisfied by several commonly employed lag-selection strategies. Simulation evidence indicates that the performance of the ADF test is considerably improved when the lag length is selected from the data. An application to inventory series illustrates that inference about a unit root can be very sensitive to the method of lag-length selection.