cssi/SciSciGPT-SciSciNet huggingface dataset:
Gangrenous cholecystitis: prediction with CT imaging

The aim of this study is to determine the usefulness of different patterns of gallbladder mucosal enhancement on contrast-enhanced computed tomography (CT) for differentiating between gangrenous and uncomplicated acute cholecystitis. This retrospective evaluation involved 56 patients with histopathologically proved acute cholecystitis (32 with gangrenous and 24 with uncomplicated acute cholecystitis) who had preoperative contrast-enhanced CT imaging. CT in 38 patients showed a gallbladder mucosal enhancement pattern that could be categorized into continuous, discontinuous, and/or irregular categories. In the other 18 patients, the mucosal enhancement pattern could not be classified due to lack of mucosal enhancement or inadequate mucosal enhancement. On contrast-enhanced CT evaluation, continuous and discontinuous and/or irregular mucosal enhancement patterns were seen in 20 and 18 patients, respectively. Among the 20 patients with continuous mucosal enhancement, 17 had uncomplicated acute cholecystitis. Seventeen of the 18 patients with discontinuous and/or irregular mucosal enhancement had gangrenous cholecystitis. The sensitivity and positive predictive value (PPV) of discontinuous and/or irregular mucosal enhancement in the diagnosis of gangrenous cholecystitis were 30.3% and 94.4% (17 of 18), respectively. The sensitivity and PPV of continuous mucosal enhancement in the diagnosis of uncomplicated acute cholecystitis were 30.3% and 85.5% (17 of 20), respectively. There was a statistically significant difference (p = 0.0005) between the PPV of discontinuous and/or irregular (94.4%) and that of continuous (15%) mucosal enhancement for predicting gangrenous cholecystitis. The pattern of gallbladder mucosal enhancement on CT can be used as a reliable criterion for distinguishing acute, uncomplicated cholecystitis from gangrenous cholecystitis.
Unintended consequences: energy R&D in a deregulated energy market

Abstract Many advanced industrialized nations are substantially reducing their national (public and private) investments in energy research and development (R&D), driven in part by changes occurring as a result of the deregulation of these nations’ energy sectors. In particular, funding for strategic energy R&D aimed at developing future energy supply options (eg, fusion, fission, ‘clean’ fossil energy, renewable energy) has been decreased substantially in both the public and private sectors in many of these nations. These trends are now starting to be seen in the United States as it moves towards the deregulation of the nation’s utilities. The magnitude of the reductions in support for energy R&D in the public and private sectors and the shift towards decidedly shorter-term R&D has profound implications for nations approaching deregulation. Though utility customers may be short-term winners from the deregulation of utilities by paying less for energy, a national failure to invest in energy R&D is very likely to have long-term negative impacts on national energy sectors, the economies, and environmental wellbeing.
Surgical treatment of Takayasu's disease

Takayasu's disease affects young females in the second and third decade of life. During the chronic phase, the aorta and its major arteries become stenotic, causing significant sequelae. Surgical treatment is possible with expectation of good results. The author advises treatment of stenotic arteries that are potentially dangerous or that adversely affect lifestyle with either percutaneous transluminal angioplasty or surgery. The author emphasizes the difference between surgical procedures for atherosclerosis versus a procedure for Takayasu's disease.
Discrepancies between two formulations of signal-to-noise ratio for background-limited detection

Different investigators have published different relationships for the same problem of predicting the signal-to-noise ratio for incoherent passive detection of infrared radiation. The results of two authors are compared, and a possible basis for the differences is explained.
Grid-size dependence of Cauchy boundary conditions used to simulate stream–aquifer interactions

Abstract This work examines the simulation of stream–aquifer interactions as grids are refined vertically and horizontally and suggests that traditional methods for calculating conductance can produce inappropriate values when the grid size is changed. Instead, different grid resolutions require different estimated values. Grid refinement strategies considered include global refinement of the entire model and local refinement of part of the stream. Three methods of calculating the conductance of the Cauchy boundary conditions are investigated. Single- and multi-layer models with narrow and wide streams produced stream leakages that differ by as much as 122% as the grid is refined. Similar results occur for globally and locally refined grids, but the latter required as little as one-quarter the computer execution time and memory and thus are useful for addressing some scale issues of stream–aquifer interactions. Results suggest that existing grid-size criteria for simulating stream–aquifer interactions are useful for one-layer models, but inadequate for three-dimensional models. The grid dependence of the conductance terms suggests that values for refined models using, for example, finite difference or finite-element methods, cannot be determined from previous coarse-grid models or field measurements. Our examples demonstrate the need for a method of obtaining conductances that can be translated to different grid resolutions and provide definitive test cases for investigating alternative conductance formulations.
Early outcomes of pyrolytic carbon hemiarthroplasty for the treatment of trapezial-metacarpal arthritis.

Purpose Pyrolytic carbon implants have been successfully used in the treatment of osteoarthritis of the metacarpophalangeal and proximal interphalangeal joints. Recently, pyrolytic carbon hemiarthroplasties have been proposed for the treatment of osteoarthritis of the trapezial-metacarpal (TM) joint of the thumb. We wished to review our short-term outcomes for this device in the treatment of TM arthritis. Methods Fifty-four arthritic TM joints in 49 patients, with a mean age of 59 years, were treated with use of a pyrolytic carbon hemiarthroplasty procedure. Underlying diagnoses included osteoarthritis in 44 thumbs, rheumatoid arthritis in 8 thumbs, psoriatic arthritis in 1 thumb, and juvenile rheumatoid arthritis in 1 thumb. The patients were followed up clinically as well as radiologically for an average of 22 months postoperatively. Results The overall 22-month survival rate excluding scaphotrapezio-trapezoidal joint arthritis was 80% according to a Kaplan-Meier analysis. Ten metacarpal subluxations were observed. Seven of these cases were salvaged by increasing the depth of the trapezial cup. A total of 15 reoperations were required in this cohort. No complications were seen in the patients with inflammatory arthritis. Thirty-five patients were pain free at the latest follow-up, and 6 reported mild to occasional pain with repetitive activities. The overall satisfaction rate was 40 of 49 patients (81%). Grip strength recovered to 86% of that of the contralateral side. Apposition key and opposition pinch strength improved to 92% and 95%, respectively, of those of the contralateral hand. Conclusions Pyrolytic carbon thumb arthroplasty may prove to be an acceptable option for the treatment of TM, although a high complication rate was observed in this early cohort, with many cases of subluxation attributed to the creation of a too shallow trapezial cup. Further comparative studies are warranted. Type of study/level of evidence Therapeutic IV.
Maximizing the Potential of Internships in Gerontology and Geriatrics

Internships and similar applied opportunities have long been valued for providing students with opportunities for practical experience, career preparation, and personal growth. The need for applied experiences in gerontology and geriatrics is particularly salient. Creating and sustaining effective internship experiences, however, requires careful attention to a variety of concerns. Using examples and illustrations from an ongoing gerontology internship component (undergraduate and graduate) this article examines ways to anticipate and address the challenges that are common to a broad range of internship experiences, as well as those that are unique to applied learning in gerontology and geriatrics.
Solubility behavior of atmospheric 7Be in the marine environment

Abstract The solubility of natural 7 Be from air particulate matter in seawater was determined as a function of time. Adsorption of the thus solubilized 7 Be on a variety of substrates was investigated. 7 Be appears to be strongly adsorbed on suspended matter and inorganic materials at high suspended loads (> 20 mg 1 −1 ), but at natural levels (∼1 mg 1 −1 ) is only partially adsorbed. Further, at natural concentrations of suspended matter, adsorption of 7 Be appears to be directly proportional to suspended load. Because a non-steady-state flux of 7 Be to the bottom could be expected over its 53-day half-life, 7 Be may be a poor tracer of sedimentation rates and sediment redistribution processes.
The Use and Impact of Fast-Track Departures: Exploring Prosecutorial and Judicial Discretion in Federal Immigration Cases

Fast-track programs allow prosecutors in authorized jurisdictions to expedite case processing for offenders charged with immigration violations. We explore whether disparities from fast-track usage exist by utilizing multilevel modeling techniques to analyze 2008 United States Sentencing Commission data on the federal sentencing of illegal entry defendants. Results indicate that the use of fast-track programs, the amount of sentence reduction applied in fast-track cases, and the overall sentence length is differentially impacted by various legal, extralegal, case processing, and district-level variables. These findings suggest some support for previous theoretical explanations for decision-making, but also indicate that these processes may differ slightly in the context of fast-track programs.
Child and adolescent inpatient restraint reduction: a state initiative to promote strength-based care

ABSTRACT Objective To reduce the use of restraint and seclusion with children and adolescents in psychiatric inpatient units by promoting a preventive, strength-based model of care. Method The State Mental Health Authority used data analysis, quality improvement strategies, regulatory oversight, and technical assistance to develop and implement system change over a 22-month period. No changes in regulation or policy were undertaken. Results Comparative data collected before and after the interventions demonstrated substantial reductions in the use of restraint and seclusion. Child units (age 5–12) decreased from 84.03 to 22.78 episodes per 1,000 patient days (72.9%), adolescent units from 72.22 to 37.99 episodes (47.4%), and mixed child/adolescent units from 73.37 to 30.08 episodes (59%). Conclusions The use of restraint and seclusion in child and adolescent inpatient settings can be reduced through a systems approach, which may have applicability to other settings and systems.
Buckling and Postbuckling of Electroconducting Elastic Plates in a Magnetic Field

The basic equations of a fully nonlinear theory of electromagnetically conducting flat plates carrying an electric current and exposed to a magnetic field of arbitrary orientation are summarized. The relevant equations have been obtained by considering that both the elastic and electromagnetic media are homogeneous and isotropic. The geometrical nonlinearities are considered in the von-Karman sense, and the soft ferromagnetic material of the plate is assumed to feature negligible hysteretic losses. Based on the electromagnetic and elastokinetic field equations, by using the standard averaging methods, the 3-D coupled problem is reduced to an equivalent 2-D one, appropriate to the theory of plates. Having in view that the elastic structures carrying an electric current are prone to buckling, by using the presently developed theory, the associated problems of buckling and post-buckling are investigated. In this context, the problem of the electrical current inducing the buckling instability of the plate, and its influence on the postbuckling behavior are analyzed. In the same context, the problem of the natural-frequencies electrical current interaction of flat plates, as influenced by a magnetic field is also addressed.Copyright © 2002 by ASME
Development and characterization of 24 microsatellite loci for the Illinois chorus frog ( Pseudacris illinoensis ) and Strecker’s chorus frog ( P. streckeri )

The Illinois chorus frog (Pseudacris illinoensis), originally described as a subspecies of Strecker’s chorus frog (P. streckeri), has a disjunct distribution in Illinois, Missouri, and Arkansas. Populations of P. illinoensis are threatened by habitat loss caused by current agricultural practices, but this taxon has not yet been assessed for the IUCN Red List. We developed 24 microsatellite loci to study the genetic structure of P. illinoensis and P. streckeri, investigate the evolutionary history of this species complex, and help inform conservation efforts. The number of alleles ranged from 4 to 13, observed heterozygosities from 0.214 to 0.889, and expected heterozygosities from 0.476 to 0.899, indicating these markers will be useful for studying population genetic variation.
Quality of long-term survival following irradiation for intracranial tumors in children under the age of two

Abstract Thirty-eight children aged two and under who received radiotherapy alone or post-operatively for primary intracranial tumors from 1957 to 1974 were retrospectively studied for survival rate, late radiation sequelae, and quality of survival. There were 24 deaths, all attributed to the primary disease or its complications. The five, ten, and fifteen year absolute survival rates were 50 %, 39 %, and 38 % respectively, with posterior fossa tumors faring best. The 14 survivors, aged 6 to 21 1 2 years, were evaluated fore physical, neurologic, endocrinologic, and psychologic abnormalities. Eight were found to have minimal or no abnormal neurologic findings, 11 were within the educable range on formal intelligence testing, and 12 had Karnofsky performance scores of 70 or better. There was little clinical evidence of severe endocrinologic dysfunction except for short stature in three. patients correlated with a dose of greater than 3600 rad to the hypothalamic-pituitary region. The patients were assigned to a proposed “Composite Quality of Survival Scale”(CQS) graded 1 to 5 based upon their overall quality of life evaluation. Eight of the patients were rated Grade 3 or better, with three patients essentially normal in most respects. We conclude that the data justify the continued use of radiotherapy in the treatment of very young children with brain tumors. However, there is the obvious need for further optimization of radiotherapy factors (time, dose, volume) in order to minimize the potential late effects of radiation to the central nervous system.
Determination of copper in saline waters by atomic absorption spectrohotometry combined with apdc-mibk extraction

Abstract A technique has been developed for the determination of copper in saline waters by extraction of its complex with ammonium pyrollidine dithiocarbamate into methyl isobutyl ketone and subsequent analysis by atomic absorption spectrophotometry. The method is self-compensating for any incomplete extraction of copper. With a 15:510 solvent-aqueous phase ratio, a sensitivity of 0.2 p.p.b. and a precision of ±10% were achieved. The method was used to determine copper in a number of sea water and other'saline water samples.
Bandwidth broadening of patch antennas using nonuniform substrates

A patch bandwidth-broadening technique is introduced by modifying the dielectric under the square patch. The dielectric modification is guided by the field intensity under the original uniform substrate. This broadening technique is particularly attractive for high-contrast substrates that are often used for miniaturization. An example design is measured for demonstration. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 421–423, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21189
Development of a peptide antibody specific to human glutathione S-transferase alpha 4-4 (hGSTA4-4) reveals preferential localization in human liver mitochondria.

The reactive cellular products generated during the peroxidation of membrane lipids have been implicated as causative agents in a variety of degenerative diseases and aging. In particular, 4-hydroxynon-2-enal (4HNE) is among the most of the produced during lipid peroxidation. In humans and rodent species, the alpha 4 subclass of glutathione S-transferases (mGSTA4-4, rGSTA4-4, hGST-5.8, and hGSTA4-4) exhibits uniquely high glutathione conjugation activity toward 4HNE and other hydroxyalkenals. In human liver, hGSTA4-4-mediated 4HNE conjugation appears to represent the high-affinity pathway for 4HNE detoxification. In the present study, a highly specific polyclonal antibody was developed against hGSTA4-4. Western blotting analysis of human liver subcellular fractions as well as N-terminal sequencing revealed that hGSTA4-4 was localized to mitochondrial fractions, but was not detected in cytosolic fractions. Our results provide evidence that in adult liver, hGSTA4-4 is specifically targeted to the mitochondrion to the apparent exclusion of the cytosol. Targeting of hGSTA4-4 to the mitochondrion holds implications for degenerative diseases associated with oxidative stress that arise from aerobic respiration.
Mechanism of uncoupling by uncouplers of oxidative phosphorylation

Abstract Classical uncouplers duplicate exactly the uncoupling actions of the valinomycin-nigericin ionophoric combination in presence of K + — a combination that mediates cyclical transport of K + driven by electron transfer or pyrophosphorolysis of ATP in mitochondria. Evidence has been presented that uncouplers have the properties essential for mediating coupled cyclical transport of cations and that uncoupling of oxidative phosphorylation can be rationalized in terms of one coupled process being displaced and replaced by another. The critical demonstrations were first that uncoupling is a cation-dependent process and that only those cations that can undergo complexation with uncouplers are effective in restoring mitochondrial uncoupler action in a cation-deficient medium. The second demonstration was that uncouplers are ionophores, not only of the nigericin type but also of the valinomycin type (electrogenic). This combination in one molecule of electrogenic as well as non-electrogenic ionophoric activity for cations endows uncouplers with the capability for duplicating the uncoupling action of the valinomycin-nigericin combination and for mediating coupled cyclical transport of cations.
Magnetic resonance imaging of isolated abdominal aortic dissection

In the absence of trauma or descending thoracic aortic dissection, abdominal aortic dissection is rare. This report presents a case of “isolated” abdominal aortic dissection. Magnetic resonance imaging may reliably diagnose and characterize these dissections without the use of contrast material.
Childlessness and the Psychological Well-Being of Older Persons

Objectives. Rapid growth in the size of the childless elderly population has prompted concerns about the negative effects of childlessness on psychological well-being. This study adds to this line of inquiry by examining the effects of childlessness on two important dimensions of elderly persons’ psychological well-being: loneliness and depression. Methods. Using the 1993 Asset and Health Dynamics Among the Oldest Old data set, the authors estimated logistic and ordinary least squares regression models of psychological well-being for a nationally representative sample of people aged 70 and older ( N � 6,517). Results. Childlessness per se did not significantly increase the prevalence of loneliness and depression at advanced ages, net of other factors. There also was no statistical evidence for the hypothesis that childlessness increases loneliness and depression for divorced, widowed, and never married elderly persons. Sex, however, altered how childlessness and marital status influenced psychological well-being. Divorced, widowed, and never married men who were childless had significantly higher rates of loneliness compared with women in comparable circumstances; divorced and widowed men who were childless also had significantly higher rates of depression than divorced and widowed women. Discussion. The findings suggest that it is important to understand the consequences of childlessness in the context of marital status and sex.
Endogenous methylarginines modulate superoxide as well as nitric oxide generation from neuronal nitric-oxide synthase: Differences in the effects of monomethyl- and dimethylarginines in the presence and absence of tetrahydrobiopterin

The endogenous methylarginines asymmetric dimethylarginine (ADMA) and N(G)-monomethyl-L-arginine (L-NMMA) regulate nitric oxide (NO) production from neuronal NO synthase (nNOS). Under conditions of L-arginine or tetrahydrobiopterin (BH(4)) depletion, nNOS also generates superoxide, O(2)(.); however, the effects of methylarginines on this O(2)(.) generation are poorly understood. Therefore, we measured the dose-dependent effects of ADMA and L-NMMA on the rate and amount of O(2)(.) production from nNOS under conditions of L-arginine and/or BH(4) depletion, using electron paramagnetic resonance spin trapping. In the absence of L-arginine, ADMA (1 microm) inhibited O(2)(.) generation by approximately 60% from a rate of 56 to 23 nmol/mg/min, whereas L-NMMA (0.1-100 microm) had no effect. L-Arginine markedly decreased the observed O(2)(.) adduct formation; however, O(2)(.) generation from the enzyme still occurs at a low rate (12.1 nmol/mg/min). This O(2)(.) leak is NOS-derived as it is not seen in the absence of calcium and calmodulin and demonstrates that O(2)(.) generation from NOS occurs even when normal substrate/ cofactor levels are present. Under conditions of BH(4) depletion, ADMA had no effect on O(2)(.), whereas L-NMMA increased O(2)(.) production almost 3-fold. This O(2)(.) generation was >90% inhibited by imidazole, indicating that it occurred at the heme center. Thus, methylarginines can profoundly shift the balance of NO and O(2)(.) generation from nNOS. These observations have important implications with regard to the therapeutic use of methylarginine-NOS inhibitors in the treatment of disease.
The Library and the Development of Online Courses

SUMMARY A survey of eight business faculty preparing online classes for a proposed distance education degree in international marketing was conducted by business librarians at Michigan State University. The results of the survey indicated that there were differences in faculty and librarian expectations as to the library support needed for the courses.
Breaking the Mold: Using Educational Pedagogy in Designing Library Instruction of Adult Learners

Summary This paper delineates the special characteristics of the adult learner, emphasizing their high level of motivation and their diverse learning styles. It introduces the 4MATR System, an instructional model developed by Bernice McCarthy, PhD which provides a systematic approach to delivering instruction that especially addresses the learning styles of adults. As a learner-focused model for adapting curriculum and instruction to the diverse needs of students, 4 MAT gives teachers/librarians a framework in which to design learning activities in a systematic cycle. The system encourages librarians to use multiple methods of instruction so as to reach students more effectively, regardless of the individual's learning style. The paper concludes with a library instruction unit designed by using the 4MATR System.
Psychometric Evaluation of the Behavioral Health Questionnaire-20: A Brief Instrument for Assessing Global Mental Health and the Three Phases of Psychotherapy Outcome

This study evaluated the psychometric properties of the 4 scales of the Behavioral Health Questionnaire-20 (BHQ-20): Global Mental Health, Well-Being, Symptoms, and Life Functioning. Four samples were used: community adults, college students, college students in counseling, and adults in outpatient psychotherapy. Support was found for internal consistency and 2-week test-retest reliability. For construct validity, the BHQ-20 scales distinguished levels of pathology among the samples and were sensitive to improvement across 3 psychotherapy sessions. Concurrent validity correlations with the scales of established measures were at least moderately high. Higher correlations were also found between the BHQ-20 scales and the nonanalogous scales of the established measures. These results, along with high correlations among the BHQ-20 scales, indicated the presence of 1 primary mental health dimension accounting for the variance. The BHQ-20 was proven to be a generally reliable, valid questionnaire that is distin...
Local chromatin changes accompany the expression of the calbindin-D28K gene: tissue specificity and effect of vitamin D activation.

The high affinity calcium-binding protein calbindin-D28K is one of the known proteins transcriptionally up-regulated by the hormonally active form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. This regulation is tissue specific, since in the absence of 1,25-(OH)2D3, the expression of calbindin-D28K is virtually abolished in intestine, whereas it is decreased, but clearly detectable, in kidney, and it remains present at its highest level in cerebellum. Several studies have shown that there is a strong correlation between an increase in the sensitivity to nuclease digestion of a given gene locus and its potential for transcription. Furthermore, hypersensitive sites have often been mapped to regions of DNA including or surrounding sequences known to be important for the regulation of gene transcription. In this study we have scanned the 5'-end and flanking DNA of the calbindin-D28K gene for the presence of DNase-I-hypersensitive (DH) sites in order to localize possible regulatory regions involved i...
Transport of multiple nicotinic acetylcholine receptors in the rat optic nerve: high densities of receptors containing α6 and β3 subunits

Neuronal nicotinic acetylcholine receptors (nAChRs) are abundant in the rat retina and at least seven heteromeric subtypes have been detected. Axons of retinal ganglion cells form the optic nerve and innervate areas of the brain important for visual processing, including the lateral geniculate nucleus, the superior colliculus, and the pretectal nucleus. Development of eye-specific layers in these projection areas are dependent upon retinal waves which are initially mediated by nAChRs [Feller et al., Science 272 (1996), 1182; Penn et al., Science 279 (1998), 2108; Bansal et al., J. Neurosci. 20 (2000), 7672]. Unilateral eye-enucleation studies in the rat indicate that nAChRs are on the terminals of optic nerve axons, where they may mediate influences of acetylcholine on visual pathways. In this study, we use radioligand binding and immunoprecipitation with subunit-selective antibodies to investigate the subunit composition of nAChRs in the rat optic nerve. We found multiple nAChR subtypes in the optic nerve, all of which contain the β2 subunit. Most of these receptors are mixed heteromeric subtypes, composed of at least three different subunits. Included among these subtypes is the highest percentage and density of α6- and β3-containing nAChRs of any area of the rat CNS that has been reported.
Assessing LGBTQ Campus Climate and Creating Change

We report the findings of a climate study of a liberal arts college in Pennsylvania. This climate assessment was comprehensive in content (heterosexual and cisgender individuals' attitudes, and LGBTQ individuals' experiences), participants (faculty, staff, and students), and methodology (qualitative and quantitative). We found low levels of sexual prejudice and generally positive perceptions of the campus, but positive attitudes were more strongly endorsed by heterosexual and cisgender than LGBTQ participants. We consider the impact of these perceptions on LGBTQ students' co-curricular involvement and discuss the institutional changes that are underway as a result of our study.
Reflection properties of phase transition and compositional change models of the 670-km discontinuity

Seismic observations of the amplitude ratio amplitude P′670P′/amplitude P′P′ suggest a reflection coefficient R ∼ 7–13% for reflections from the underside of the 670-km discontinuity. This can be compared with calculated reflection coefficients to constrain the nature of the mantle transition region. Velocity and density profiles through the transition region were calculated for olivine, pyroxene, garnet, and olivine + garnet model mineral assemblages. For models with identical upper and lower mantle compositions, the computed reflection coefficients from the phase transitions pertinent to the 670-km discontinuity are less than 0.5%. These phase transitions produce their maximum R if they are effectively discontinuous, which gives R ∼ 2–3%, except for the garnet to perovskite transformation which gives R ∼ 8%. In general, given realistic impedance contrasts across a phase transition, the change in material properties must occur over a region less than 3 km thick for R to be of the order of 5%. A discontinuous change in chemical composition at 670-km depth, coupled with a change in phase, can also produce a reflection coefficient of the observed magnitude: R ∼ 2–3% for a first-order change in phase at 670 km with different iron concentrations on each side of the discontinuity, and R ∼ 4–6% for cases with a discontinuous increase in silica content. Based on our analysis, the thermal and chemical boundary layers which would occur across such a chemical discontinuity would probably have negligible effects on the reflection coefficient. Thus although limited by considerable uncertainties, the mineralogical and seismic data suggest a two-layered model of the mantle with a discontinuous change in both phase and composition at 670 km.
A Pilot Study Examining the Performance of Polynomial-Modeled Ventricular Shock Electrograms for Rhythm Discrimination in Implantable Devices

Background: Inappropriate shocks continue to be a problem for patients with implantable defibrillators (ICD). We evaluated the performance of polynomial-modeled ventricular electrograms (EGM) to discriminate between supraventricular tachycardia (SVT) and ventricular tachycardia (VT). Methods: Seven sets of EGM from patients having both SVT and VT documented during a single ICD interrogation were included. The cardiac cycle was analyzed off-line in two parts, QR and RQ segments, which were modeled separately using third-order and sixth-order polynomial equations, respectively. These segments were then analyzed to determine which polynomial coefficients were most significant for rhythm discrimination. Results: When analyzing the QR segment during arrhythmia, there were statistically significant (P < 0.05) correlations in 4 of 4 (100%) of the QR coefficients when comparing normal sinus rhythm (NSR) to SVT and 2 of 4 (50%) when comparing NSR to VT or SVT to VT. When analyzing the RQ segment during arrhythmia, there were statistically significant (P < 0.05) correlations in 4 of 7 (57%) of the RQ coefficients when comparing NSR to SVT, 5 of 7 (71%) when comparing NSR to VT, and 3 of 7 (43%) when comparing SVT to VT. Using a cutoff value of 50% change from NSR, the ratio of first-order to zero-order QR coefficient was able to completely separate VT from SVT (P = 0.03) in this series of patients. Conclusion: Our data demonstrate the feasibility of simple polynomial equations that reproduce the depolarization and repolarization phases of human ventricular shock EGM. The ratio of first-order to zeroorder QR coefficient was able to reliably discriminate between SVT and VT while reducing the polynomial model to a first-order system. The results of this pilot trial may serve as the basis for a larger prospective trial implementing a discrimination algorithm for use in low computational power implantable devices. (PACE 2006; 29:930‐939)
Evaluating Safer Conception Options for HIV-Serodiscordant Couples (HIV-Infected Female/HIV-Uninfected Male): A Closer Look at Vaginal Insemination

HIV serodiscordant couples represent at least half of all HIV-affected couples worldwide. Many of these couples have childbearing desires. Safer methods of conception may allow for pregnancy while minimizing the risk of sexual transmission of HIV. In serodiscordant partnerships with an HIV-infected female and HIV-uninfected male, vaginal insemination of a partner's semen during the fertile period coupled with 100% condom use may be the safest method of conception.
A rational route to probing membrane proteins

A recent report describes the design of short peptides that bind specifically to transmembrane regions of integrins, providing an exciting tool for probing the biology of membrane proteins.
THE LOGIC OF POSITIVE ACCOUNTING RESEARCH

Abstract Positive accounting research consists of tests of positive accounting theory; it is a substantial body of important accounting literature. The discussion in this paper is aimed at demonstrating that a problem in experimental procedure exists with such research that is created when positive accounting researchers translate the theoretical language of positive accounting theory into an empirical language that permits experimentation. Experimentally, positive accounting theory is transformed into a tautology. Experimenters define a causal variable in terms of the phenomenon they wish to explain with it. This transforms accounting practice into its own explanation, which is not quite the improvement in our understanding envisioned by positive accounting theory. In addition, the paper includes the demonstration that any plausible argument available to defend positive accounting research against the accusation that it creates a tautology requires that damage be done to the theory that informs such research.
Relationship of DNA degradation by Saccharomyces cerevisiae Exonuclease 1 and its stimulation by RPA and Mre11-Rad50-Xrs2 to DNA end resection

Homologous recombination is a major pathway for repair of DNA double-strand breaks. This repair process is initiated by resection of the 5′-terminated strand at the break site. In yeast, resection is carried out by three nucleolytic complexes: Mre11-Rad50-Xrs2, which functions at the initial step and also stimulates the two processive pathways, Sgs1-Dna2 and Exonuclease 1 (Exo1). Here we investigated the relationship between the three resection pathways with a focus on Exo1. Exo1 preferentially degrades the 5′-terminal stand of duplex DNA that is single stranded at the 3′ end, in agreement with its role downstream of the Mre11-Rad50-Xrs2 complex. Replication protein A (RPA) stimulates DNA end resection by Exo1 by both preventing nonspecific binding of Exo1 to and preventing degradation of single-stranded DNA. Nucleolytic degradation of DNA by Exo1 is inhibited by the helicase-deficient Sgs1 K706A mutant protein and, reciprocally, the nuclease-deficient Exo1 D173A mutant protein inhibits DNA unwinding by Sgs1. Thus, the activities of Sgs1 and Exo1 at DNA ends are mutually exclusive, establishing biochemically that both machineries function independently in DNA end processing. We also reconstituted Sgs1-Top3-Rmi1-RPA-Dna2 and Exo1 resection reactions both individually and combined, either with or without the Mre11-Rad50-Xrs2 complex. We show that the yeast Sgs1-Dna2 and Exo1 pathways do not stimulate one another and function as independent and separate DNA end-processing machineries, even in the presence of the stimulatory Mre11-Rad50-Xrs2 complex.
Independence of Geomagnetic Polarity Intervals

Summary The statistical independence of sequences of geomagnetic polarity intervals has been investigated using correlation analysis to test the hypothesis that reversals are generated by a renewal process. In the analysis, the sequence of Cenozoic geomagnetic reversals as determined from palaeomagnetic studies was first divided into two sub-intervals during which the reversal process was stationary. Within both of these sub-intervals the lengths of successive polarity intervals are statistically independent. The present analysis does not support an earlier interpretation that reversals are generated by a Markov process. Instead they are found to be consistent with generation by a renewal process.
Self-Folding Smart 3D Microstructures Using a Hydrogel-Parylene Bilayer

This paper describes a new method of fabricating 3D microstructure by using the self-folding of hydrogel-parylene bilayer. The environmental responsive properties of the hydrogel allows for automated bending 3D microstructures upon exposure to a chemical or physical stimuli. For a highly cross-linked pH-sensitive hydrogel, bending of the bilayer structure can be completed in 6 seconds when pH value is changed from 2.0 to 9.0.
Low‐Energy Selective Capture of Carbon Dioxide by a Pre‐designed Elastic Single‐Molecule Trap

isotherms, binary gas adsorption studies by simulations and experiments, and crystallographic determination of the adsorbed gas. Through molecular-level control of a material, our results demonstrate the design and synthesis of a new class of low-energy CO2 sorbents. It has been proposed that by shifting focus from energy consuming aqueous alkanolamine solutions to physisorptive materials, the estimated cost of CCS (70 % of which is derived from the capture step) can be drastically lowered through materials optimization. [7] Previously, we synthesized meshadjustable molecular sieves (MAMS) capable of adsorbing specific gas molecules in a narrow temperature range through designed stimuli-responsive gating effects. [8] These materials were constructed of weakly bonded (van der Waals interactions, vdW) sheets with one-dimensional gated channels. The problem of applying these materials to harsh flue gas applications lays primarily in the stability of the intersheet bonding interactions. Herein we report the rational design of the next generation material, in which this problem is overcome by introducing strong coordination bonds between the layers. The vast choice of ligands was narrowed down to a short interlayer distance to fit exactly one CO2 molecule into the elastic polar pocket of PCN-200 while designing CO2 specific interactions. The resulting multipoint bonding of CO2 to a precisely designed pocket is reminiscent of the biomimetic recognition employed by receptors in nature to accommodate exactly one guest molecule. The framework organizing these traps in space, [Cu(tzc)(dpp)0.5]n·1.5 H2O (PCN-200-syn, tzc = tetrazolate-5-carboxylate, dpp = 1,3-di(4-pyridyl)propane), has proper Cu···Cu distances in the direction of the b axis to form CO2 pockets, controlled by m3-bridging tzc ligands forming layers in the bc plane (Figure 1 b). The flexible N-donor linker dpp (Fig
Multicore-Aware Code Positioning to Improve Worst-Case Performance

Inter-thread interferences in shared caches can significantly affect the worst-case execution time (WCET) of real-time tasks running on multi-core chips. In this paper, we study three multicore-aware code positioning methods to reduce the inter-core L2 cache interferences between co-running real-time threads. One strategy focuses on decreasing the longest WCET among the co-running threads, and two other methods aim at achieving fairness in terms of the amount or percentage of WCET reduction among co-running threads. Our experiments indicate that the proposed multicore-aware code positioning approaches not only improve the worst-case performance of the real-time threads, but also make tradeoffs between efficiency and fairness for threads running on multi-core platforms.
Effects of relative humidity on the basal expansion of Mg-smectite equilibrated with ethylene glycol at low vapor pressure

The effects of relative humidity (RH) on the expansion of Mg-smectite, equilibrated with low vapor pressure of ethylene glycol (EG), was studied. Four smectite samples were equilibrated with EG vapor from: (1) saturated vapor of pure EG, (2) an EG-CaCI2 solvate, and (3) 0.05 relative EG vapor pressure at 65"C. X-ray powder diffraction (XRD) analyses of the clays under different RH conditions indicated that without EG, the basal spacing of Mg-smectite samples could only be expanded to 16 A, even at 0.97 RH. The basal spacing of Mg-smectite samples equilibrated with saturated EG vapor was expanded to 17.1 .A, and was not significantly affected by RH in the range 0.1-0.9. The basal spacing of the Mg-smectite samples equilibrated with vapor from the EG-CaC12 solvate and 0.05 relative EG pressure at 65~ was expanded by an amount that depended on the RH during the XRD analysis. The basal spacing increased from 14.2 to 17.1 A as the RH increased from 0.6 to 0.75, except for sample API 23, which expanded to 17.1 A at RH > 0.9. This sample did not expand beyond 16 .~ when it was equilibrated with 0.05 EG relative vapor pressure. Sorption of moisture from air caused the one-layer EG-Mg-smectite complex (basal spacing = 14.1 A) to rearrange itself to a double-layer EG-Mg-smectite complex (basal spacing = 17.1 A). A small amount of the adsorbed EG in Mg-smectite, much less than was needed to cover a one-layer of the interlayer surfaces, caused an expansion of the basal spacing to 17.1 A at high RH during the XRD analysis. The minimum amount of adsorbed EG which caused the one-/two-layer EG complex conversion was about 20-30 mg EG/g. The conversion was fast (<5 min) and was relatively reversible.
Survey of Freshwater Mussels (Bivalvia: Unionoidea) in the Marais des Cygnes River, Fall River, and Grouse Creek

Abstract The status of freshwater mussels (Bivalvia: Unionoidea) has declined over the last 30 years such that they are one of the most imperiled taxonomic groups in North America. Mussel populations in Kansas have followed a similar trend of decline. To better understand the status of mussels in the state, Kansas Department of Wildlife and Parks has established a monitoring program in which 10 river basins containing “high priority” mussel communities will be surveyed every six years. We surveyed mussels on three rivers in eastern Kansas during the summers of 2003 and 2004: Marais des Cygnes River, Fall River, and Grouse Creek. To achieve quantifiable, repeatable survey data, 40 1-m2 randomly selected quadrats were searched for mussels at each site. Using 1,010 quadrats, we sampled 26 sites among the three rivers and encountered 4,522 mussels (density = 4.5 mussels per m2) and 25 species. We also conducted timed searches at each site to better understand community structure and to increase the probabilit...
Food thermophysical property models

The design engineer must predict the thermophysical properties of foods in order to design food storage and refrigeration equipment and estimate process times for refrigerating, freezing, heating or drying of foods. Since the thermophysical properties of foods are strongly dependent upon chemical composition and temperature, composition based models provide a means of estimating these properties. Numerous models of this type have been proposed and the designer of food processing equipment is thus faced with the challenge of selecting appropriate models from the plethora of those available. This paper describes selected food thermophysical property models and evaluates their performance by comparing their results to experimental thermophysical property data. The results given in this paper will be of value to the design engineer in the selection of appropriate food thermophysical property models.
ENRICHED ELEMENT-FREE GALERKIN METHODS FOR CRACK TIP FIELDS

SUMMARY The Element-Free Galerkin (EFG) method is a meshless method for solving partial di⁄erential equations which uses only a set of nodal points and a CAD-like description of the body to formulate the discrete model. It has been used extensively for fracture problems and has yielded good results when adequate refinement is used near the crack tip, but stresses tend to be oscillatatory near the crack tip unless substantial refinement is used. An enriched EFG formulation for fracture problems is proposed. Two methods are used: (1) adding the asymptotic fields to the trial function and (2) augmenting the basis by the asymptotic fields. A local mapping of the enriched fields for curved cracks is also described. Results show that both methods greatly reduce stress oscillations and allow the calculation of accurate stress intensity factors with far fewer degrees of freedom. ( 1997 by John Wiley & Sons, Ltd.
Vascular rarefaction in peripheral skeletal muscle after experimental heart failure.

A decrease in vascular density in peripheral skeletal muscle has been associated with exercise intolerance in humans with congestive heart failure (CHF). The purpose of this study was to determine whether CHF results in a reduction in vascular density in peripheral skeletal muscle. In this established model, CHF was induced by coronary artery ligation in New Zealand White rabbits and sham rabbits that underwent an identical surgical procedure without ligation of the coronary artery. At study termination, rabbits underwent hemodynamic testing and skeletal muscle analysis. The first series of rabbits was divided into sham (n = 6) and CHF (n = 6) 21 days postoperatively. Ten CHF rabbits were then examined 3 (n = 3), 7 (n = 3), and 14 days (n = 4) postoperatively. Vascular density in sham tibialis anterior muscle was 347 ± 41 capillaries/mm2 or 1.20 ± 0.11 capillaries/muscle fiber. In 21-day CHF rabbits, the capillary density was significantly lower, 236 ± 14 capillaries/mm2 or 0.84 ± 0.04 capillaries/muscle ...
Induction of systemic and therapeutic antitumor immunity using intratumoral injection of dendritic cells genetically modified to express interleukin 12

Bone marrow-derived dendritic cells (BM-DCs) retrovirally transduced with genes encoding murine interleukin (IL)-12 stably expressed bioactive IL-12 protein at high levels. Intratumoral injection with IL-12 gene-modified BM-DCs resulted in regression of day 7 established weakly immunogenic tumors (MCA205, B16, and D122). This antitumor effect was substantially better than that of IL-12-transduced syngeneic fibroblasts or nontransduced BM-DCs. Furthermore, intratumoral injection with IL-12-transduced dendritic cells (DCs) induced specific TH1-type responses to the tumor in regional lymph nodes and spleen at levels greater than those of IL-12-transduced fibroblasts or nontransduced BM-DCs. Trafficking studies confirmed that intratumorally injected IL-12-transduced DCs, but not fibroblasts, could migrate to the draining lymph node to the same extent as nontransduced BM-DCs. This strategy designed to deliver genetically modified DCs to tumor sites is associated with systemic and therapeutic antitumor immunity and is an alternative approach to those that use delivery of DCs loaded with tumor antigen. These results support the clinical application of IL-12 gene-modified DCs in patients with cancer.
Imperfect Substitutes: The Local Political Economy of Informal Finance and Microfinance in Rural China and India

Abstract Banking authorities in both China and India have attempted to limit most forms of informal finance by regulating them, banning them, and allowing certain types of microfinance institutions. The latter policy aims to increase the availability of credit to low-income entrepreneurs and eliminate their reliance on usurious financing. Nonetheless, the intended clients of microfinance continue to draw on informal finance in both rural China and India. This article argues that the persistence of informal finance may be traced to four complementary reasons––the limited supply of formal credit, limits in state capacity to implement its policies, the political and economic segmentation of local markets, and the institutional weaknesses of many microfinance programs.