cssi/SciSciGPT-SciSciNet huggingface dataset:
Cardiac Wall Mechanics and Torsion of the Left Ventricle during Ejection

Mathematical modeling is a common approach to study the mechanics of the wall of the left ventricle. In designing such a model generally symplifying assumptions are proposed on left ventricular geometry, myocardial tissue properties and stress or strain distribution across the wall. Common assumptions on geometry are a spherical (6, 8), a cylindrical (2) or ellipsoidal (7,10,12) shape of the left ventricle. Generally myocardial tissue is considered to be isotropic despite its obviously anisotropic properties. We developed a cylindrical, thick-walled model (1,2) which differs from other models by considering anisotropy of myocardial tissue and torsion of the left ventricle. Torsion reflects rotation of the apex with respect to the base around the long axis of the left ventricle, and is associated with shear deformation of the outer surface (epicardium) of the left ventricle when using a cylindrical coordinate system.
Computed tomography feature of synovial osteochondromatosis

Synovial osteochondromatosis in the knee joint is rarely a confusing diagnostic problem. Diagnosis depends on the clinical circumstances of the case and a radiologic interpretation which can exclude soft tissue tumors with calcifications and other malignant tumors characterized by the presence of multiple osteo-cartilaginous bodies. The relative value of computed tomography (CT) in the diagnosis of synovial osteochondromatosis is emphasized and the differential diagnosis discussed.
Treatment of a primary intracranial germ cell tumor with systemic chemotherapy

Primary germ cell neoplasms of the central nervous system (CNS) are rare tumors which generally respond to radiotherapy. Experience is limited in managing the refractory patient. We report a patient whose suprasellar dysgerminoma responded completely to 5,000 rad. Seven years later, disease recurrence was refractory to an additional 4,000 rad. Theorizing that the ''blood-brain barrier'' was no longer intact after extensive radiotherapy and tumor involvement of the ventricular system, the patient was treated with systemic bleomycin, cisplatin, and vinblastine. Pharmacokinetic studies revealed that the bleomycin and cisplatin entered the cerebrospinal fluid. Serial CT scans and CSF levels of beta-HCG confirmed the clinical impression of a partial remission. Subsequent tumor progression was refractory to therapy with intraventricular bleomycin. It is concluded that systemic chemotherapy may be beneficial in certain cases of CNS germ cell neoplasms.
Frequency specific modulation of bone adaptation by induced electric fields

A frequency specificity for the response of bone tissue to a physical stimulus is proposed. This is obtained by comparing the spectral power of exogenously induced electric fields to the efficacy of those fields to inhibit immobilization induced bone loss in an in vivo model of skeletal adaptation. Analysis of a family of related waveforms shows that the effectiveness of the induced electric fields could be related to the induced spectral power below approximately 75 Hz. The analysis suggests that bone tissue may be extremely sensitive to induced power levels at or below this frequency, as amplitude variations of less than a factor of two within this range correspond to significantly different bone remodeling responses. The analysis also suggests that bone tissue may be strongly frequency selective, with bone capable of responding specifically to induced power in this osteogenic frequency band, even though the band includes less than 0.1% of the total induced power. As normal functional activity generates strain components encompassing this osteogenic frequency band, a distinct frequency selectivity may indicate that the tissue response is tuned to a specific endogenous stimulus. A detailed characterization of the frequency response of bone tissue could well point to the primary source for the control of the cells responsible for functional adaptation in the skeleton.
Pyroxferroite: Stability and X-ray Crystallography of Synthetic Ca0.15Fe0.85SiO3 Pyroxenoid.

Synthetic Ca0.15Fe0.85SiO3 pyroxenoid has the same (pyroxmangite) structure and very nearly the same composition as pyroxferroite, a new mineral found in Apollo 11 lunar samples. The synthetic material is not stable below pressures of approximately 10 kilobars. It appears likely that the lunar pyroxferroite has persisted in a metastable state for some billions of years.
The Evolution of Eriksonian and, Neo-Eriksonian Identity Theory and Research: A Review and Integration

The evolution of the study of identity development is traced from Freud's early writings to Erikson's extrapolations and theoretical expositions, Marcia's empirical operationalization, and finally to 6 alternative theories that have been introduced since 1987 (Berzonsky, Grotevant, Waterman, Kurtines, Adams, and Cote. The issues of measurement and intervention, which have been crucial to the evolution of identity as a researchable construct, are also reviewed. The alternative theories are conceptualized as addressing aspects of Erikson's work that were not addressed by Marcia's identity status model. To facilitate the broadening of identity theory to include more of Erikson's ideas, taxonomies for understanding relations among the alternative theories, and a system for integrating them, is introduced. Finally, suggestions for the development of future identity theory and research are offered.
Mining long sequential patterns in a noisy environment

Pattern discovery in long sequences is of great importance in many applications including computational biology study, consumer behavior analysis, system performance analysis, etc. In a noisy environment, an observed sequence may not accurately reflect the underlying behavior. For example, in a protein sequence, the amino acid N is likely to mutate to D with little impact to the biological function of the protein. It would be desirable if the occurrence of D in the observation can be related to a possible mutation from N in an appropriate manner. Unfortunately, the support measure (i.e., the number of occurrences) of a pattern does not serve this purpose. In this paper, we introduce the concept of compatibility matrix as the means to provide a probabilistic connection from the observation to the underlying true value. A new metric match is also proposed to capture the "real support" of a pattern which would be expected if a noise-free environment is assumed. In addition, in the context we address, a pattern could be very long. The standard pruning technique developed for the market basket problem may not work efficiently. As a result, a novel algorithm that combines statistical sampling and a new technique (namely border collapsing) is devised to discover long patterns in a minimal number of scans of the sequence database with sufficiently high confidence. Empirical results demonstrate the robustness of the match model (with respect to the noise) and the efficiency of the probabilistic algorithm.
A Conserved Amphipathic Ligand Binding Region Influences K-Path-Dependent Activity of Cytochrome c Oxidase

A conserved, crystallographically defined bile acid binding site was originally identified in the membrane domain of mammalian and bacterial cytochrome c oxidase (CcO). Current studies show other amphipathic molecules including detergents, fatty acids, steroids, and porphyrins bind to this site and affect the already 50% inhibited activity of the E101A mutant of Rhodobacter sphaeroides CcO as well as altering the activity of wild-type and bovine enzymes. Dodecyl maltoside, Triton X100, C12E8, lysophophatidylcholine, and CHOBIMALT detergents further inhibit RsCcO E101A, with lesser inhibition observed in wild-type. The detergent inhibition is overcome in the presence of micromolar concentrations of steroids and porphyrin analogues including deoxycholate, cholesteryl hemisuccinate, bilirubin, and protoporphyrin IX. In addition to alleviating detergent inhibition, amphipathic carboxylates including arachidonic, docosahexanoic, and phytanic acids stimulate the activity of E101A to wild-type levels by providin...
A power analysis of methods for assessment of change in seagrass cover

Abstract Blade counts and biomass measurements from cores were compared with quadrat surveys in terms of the minimum sample sizes required to detect changes in seagrass cover with specified statistical power levels. Blade counts and biomass methods required extremely high replicate numbers to detect differences in seagrass cover. Percent cover estimation using quadrats required the fewest replicates and the least sampling effort for detection of a given magnitude difference, and is therefore the more cost effective method. Use of a 2 m 2 quadrat balances field effort with the number of replicate samples required to detect a difference, while allowing the statistical power of the test to remain high.
Switched-state control of a vibration isolation mount using ionomeric materials

Materials that exhibit controllable modulus variations will enable new developments in applications in vibration suppression and shape change. In this paper we analyze a class of materials that exhibits reversible modulus variations due to solvent incorporation or removal. These materials, known as ionomeric polymers, have been shown previously to exhibit 20X changes in modulus depending on the hydration state of the material. A test fixture that allows a ionomeric polymer sample to be placed in a hydration controlled environment is developed. The Young's modulus of unplated materials and materials plated with metal is measured as a function of hydration level. A change of 2.56 and 3.89 times in modulus is obtained for the unplated and plated material, respectively. Experiments are performed to determine the ability to increase the stiffening rate of the polymer using applied electrical energy. Square input signals are applied to increase the elastic modulus of these materials. The rate of modulus change is higher or lower depending on the voltage amplitude and the forcing frequency of the input signal. Different kinds of solvents are used to control the modulus of the ionomer plated with platinum. Glycerol is the solvent with the highest modulus reduction (88.87%) and water is the smallest (67.71%). In addition, a test fixture consisting of a mass on a plate is built and modeled as moving-base. The change in stiffness is explored as a method to reduce unwanted vibration. The displacement transmissibility versus frequency is measured for water and acetonitrile solvents. The stiffness of Nafion 117 is computed when the solvents are applied and after they dry. The steady state response of the system is measured by applying a sinusoidal input signal. A forcing frequency of 94 Hz near the natural frequency is selected to produce a high amplitude. The displacement amplitude is reduced 5 times in 10 seconds after the application of the acetonitrile to the ionomeric polymer. These results demonstrate the basic feasibility of controlling the modulus in real time and quantify the time constants associated with hydration and dehydration of the material.
Transnational Politics in Ethiopia: Diasporas and the 2005 Elections

Terrence LyonsGeorge Mason UniversityBeginning with a discussion of new political processes in transna-tional social networks, this essay presents Ethiopians in NorthAmerica as a conflict-generated transnational diaspora closelyinvolved in homeland politics. The essay surveys a range of key dia-spora political organizations and media, detailing their involvementin the dramatic political events surrounding the Ethiopian election in2005. The critical and creative roles that the Ethiopian diasporaplayed—in framing political events and as a gatekeeper foroppositionstrategies—provided essential support for the homeland’s oppositionparties both during and after the election. (6 March 2009)Political dynamics around the world have been transformed byglobalization and the development of innovative transnationalsocial networks. These new political processes are rooted in commu-nities that are increasingly less restricted by geographic location. Asa result, the constituencies participating in a particular politicalcampaign may live in different countries or move between locations.Networks of interlinked activists and supporters are less bound bythe need to work in close proximity to the homeland or to acceptthe notion that actors outside a state or territory are not membersof communities rooted within a specific jurisdiction. While politicshas been delinked from territory with respect to processes andactors, this does not mean that transnational politics generallyfocus on universal issues such as global social justice or cosmopoli-tan democracy. Rather, much of the new transnational politics isintensely focused on specific locations, identities, and issues.Politics remains fundamentally about local, parochial issues evenwhile political processes are increasingly transnational (Al-Ali andKoser; Lyons and Mandaville).Terrence Lyons, “Transnational Politics in Ethiopia: Diasporas andthe 2005 Elections,” Diaspora 15.2/3 (2006): 265–284. © 2011Diaspora: a journal of transnational studies.Diaspora 15:2/3 2006265
I-THM formation and speciation: preformed monochloramine versus prechlorination followed by ammonia addition.

An increasing number of utilities in the United States have been switching from chlorination to chloramination practices to comply with the more stringent trihalomethane (THM) and haloacetic acid (...
Simulation and fabrication of a new novel 3D injectable biosensor for high throughput genomics and proteomics in a lab-on-a-chip device

Biosensors are used for the detection of biochemical molecules such as proteins and nucleic acids. Traditional techniques, such as enzyme-linked immuno-sorbent assay (ELISA), are sensitive but require several hours to yield a result and usually require the attachment of a fluorophore molecule to the target molecule. Micromachined biosensors that employ electrical detection are now being developed. Here we describe one such device, which is ultrasensitive, real-time, label free and localized. It is called the nanoneedle biosensor and shows promise to overcome some of the current limitations of biosensors. The key element of this device is a 10 nm wide annular gap at the end of the needle, which is the sensitive part of the sensor. The total diameter of the sensor is about 100 nm. Any change in the population of molecules in this gap results in a change of impedance across the gap. Single molecule detection should be possible because the sensory part of the sensor is in the range of bio-molecules of interest. To increase throughput we can flow the solution containing the target molecules over an array of such structures, each with its own integrated read-out circuitry to allow 'real-time' detection (i.e. several minutes) of label free molecules without sacrificing sensitivity. To fabricate the arrays we used electron beam lithography together with associated pattern transfer techniques. Preliminary measurements on individual needle structures in water are consistent with the design. Since the proposed sensor has a rigid nano-structure, this technology, once fully developed, could ultimately be used to directly monitor protein quantities within a single living cell, an application that would have significant utility for drug screening and studying various intracellular signaling pathways.
Evaluation and assessment of a biomechanics computer-aided instruction

The Biomechanics Tutorial (BT) is a computer-aided instructional (CAI) tool that expedites the transition from lecture to application for students in an introductory biomechanics class. It contains a review of basic concepts of rigid body mechanics and functional anatomy and combines them in a way that the student can become confident and efficient in building biomechanical models. The tutorial was used by juniors and seniors. The Biomechanics Tutorial contains mechanics and yanatomy reviews and quizzes, quiz results, examples of simulations, a study guide, and practical anatomical simulations that are presented as laboratory exercises for students to explore and analyze. We conducted an objective evaluation using statistical analyses and a subjective evaluation using student questionnaires to assess the tutorial as an instructional aid that accompanied the professor's explanations of basic mechanics and functional anatomy concepts. Pre-tutorial mechanics quiz scores indicated that 86% of the students did not have sufficient mastery of mechanics concepts. The BT significantly (p<0.05) improved the performance on the post-tutorial mechanics quiz. A regression model used to test the effect of the tutorial on final grade while controlling for confounding factors (i.e., GPA and prerequisite classes), did not show that the BT significantly improved the final grades between the control and treatment groups. Students felt the BT was successful in helping them to better understand the principles of industrial ergonomics. This evaluation of the Biomechanics Tutorial is a contribution to the limited amount of research that shows a positive effect of CAI on college student achievement. The results of this study are discussed.
Preferential delivery of the Sleeping Beauty transposon system to livers of mice by hydrodynamic injection

Nonviral, DNA-mediated gene transfer is an alternative to viral delivery systems for expressing new genes in cells and tissues. The Sleeping Beauty (SB) transposon system combines the advantages of viruses and naked DNA molecules for gene therapy purposes; however, efficacious delivery of DNA molecules to animal tissues can still be problematic. Here we describe the hydrodynamic delivery procedure for the SB transposon system that allows efficient delivery to the liver in the mouse. The procedure involves rapid, high-pressure injection of a DNA solution into the tail vein. The overall procedure takes <1 h although the delivery into one mouse requires only a few seconds. Successful injections result in expression of the transgene in 5-40% of hepatocytes 1 d after injection. Several weeks after injection, transgene expression stabilizes at approximately 1% of the level at 24 h, presumably owing to integration of the transposons into chromosomes.
Adhesion and Cohesion

The phenomena of adhesion and cohesion are reviewed and discussed with particular reference to dentistry. This review considers the forces involved in cohesion and adhesion together with the mechanisms of adhesion and the underlying molecular processes involved in bonding of dissimilar materials. The forces involved in surface tension, surface wetting, chemical adhesion, dispersive adhesion, diffusive adhesion, and mechanical adhesion are reviewed in detail and examples relevant to adhesive dentistry and bonding are given. Substrate surface chemistry and its influence on adhesion, together with the properties of adhesive materials, are evaluated. The underlying mechanisms involved in adhesion failure are covered. The relevance of the adhesion zone and its importance with regard to adhesive dentistry and bonding to enamel and dentin is discussed.
Contact inhibition and gene expression in HTC-L cell hybrid lines.

Contact-inhibited somatic cell hybrids were formed between two malignant cell lines lacking contact inhibition of growth. One cell line was HTC-AR1, an azaguanine-resistant subline from the rat hepatoma line HTC +; the other line was the BUDR-resistant mouse L-cell subline L-B82. Hybrids were obtained from selective medium and characterized by chromosomal and enzymic analysis. The hybrids lacked the inducible rat enzyme tyrosine aminotransferase.
On Populist Reason and Populism and the Mirror of Democracy

On Populist Reason. By Ernesto Laclau. New York: Verso, 2005. 224p. 20.00 paper.Populism and the Mirror of Democracy. Edited by Francisco Panizza. New York: Verso, 2005. 288p. 25.00 paper.In the wake of Thomas Frank's bestselling book What's the Matter With Kansas (2004), scholars and citizens are turning to the concept of populism as a way to make sense of the strength and popularity of the far Right in the United States. In order to unravel the puzzle of why working-class voters would enthusiastically support a political party that is committed to cutting taxes for the wealthy, dismantling popular social programs, and subsidizing corporate welfare, scholars need to jettison the old Marxist-inspired paradigm that assumes that political identities are products of economic interests. At least that is one of the lessons of Ernesto Laclau's fascinating book.
HIV-1 entry inhibitors: recent development and clinical use.

Purpose of review This review provides an overview of HIV-1 entry inhibitors, with a focus on drugs in the later stages of clinical development. Recent findings Entry of HIV-1 into target cells involves viral attachment, co-receptor binding, and fusion. Antiretroviral drugs that interact with each step in the entry process have been developed, but only two are currently approved for clinical use. The small molecule attachment inhibitor BMS-663068 has shown potent antiviral activity in early phase studies, and phase 2b trials are currently underway. The postattachment inhibitor ibalizumab has shown antiviral activity in phase 1 and 2 trials; further studies, including subcutaneous delivery of drug to healthy individuals, are anticipated. The CCR5 antagonist maraviroc is approved for use in treatment-naive and treatment-experienced patients. Cenicriviroc, a small-molecule CCR5 antagonist that also has activity as a CCR2 antagonist, has entered phase 2b studies. No CXCR4 antagonists are currently in clinical trials, but once daily, next-generation injectable peptide fusion inhibitors have entered human trials. Both maraviroc and ibalizumab are being studied for prevention of HIV-1 transmission and/or for use in nucleoside reverse transcriptase inhibitor-sparing antiretroviral regimens. Summary Inhibition of HIV-1 entry continues to be a promising target for antiretroviral drug development.
Su1426 Do Clinical Outcomes After ERCP With Pancreatic Duct Stenting Predict Clinical Outcomes After Lateral Pancreaticojejunostomy for Patients With Chronic Pancreatitis

in the immediate and long term relief of pain due to chronic pancreatitis. A slightly greater percentage of patients showed long term benefit in pain relief in comparison to immediate pain relief (76.1% vs.75.7% respectively). In contrast, patients with pancreatic strictures had a better immediate response rather than on follow up (74.7% to 67.5%). In this subset of patients, endotherapy may not be as beneficial for sustained pain relief. Large prospective multicenter trials are warranted to further evaluate the benefit of endotherapy for managing chronic pancreatitis pain and decreasing the heterogeneity of currently published data.
Comparison of synchronous condenser and STATCOM for inertial response support

This paper shows a comparison between synchronous condenser (SC) and STATCOM in terms of inertia frequency response (IFR) with synchronous generator (SG). It has long been argued that, as a rotating-mass-based reactive power compensation device, SC will contribute to the total inertia of the network from its stored kinetic energy. Whereas, its counterpart, the voltage source converter (VSC) based STATCOM, will only supply reactive power and maintain voltage balance. However, the energy stored in the dc-link capacitor of the STATCOM, especially the cascaded inverter based STATCOM whose dc-link capacitance is relatively large, if properly controlled, can also contribute to the IFR. A matlab/Simulink model of SG equipped with SC and STATCOM is presented in this paper. It is demonstrated that STATCOM can provide competitive or even better IFR during disturbance condition. Both theoretical and simulated results are provided.
The effects of surface poisoning by HCl on cyclization processes on a Cu3Pt() surface

Abstract The effects of surface poisoning on the dehydrocyclization processes for C 6 hydrocarbons are analyzed. 6-bromo-1-hexene and 1-hexene reactions on the Cu 3 Pt(1 1 1) surface leading to benzene formation can be inhibited completely when the alloy surface is predosed with HCl as a chlorinating agent. The Cu:Pt ratio on a surface of the alloy crystal did not change significantly upon addition of HCl within the errors of our measurements. The rates of dehydrocyclization processes were suppressed as a linear function of the HCl dosed. Thermal desorption mass spectrometry and Auger electron spectroscopy were used to characterize the surface processes and obtain experimental information about the mobility of chlorine on the alloy surface and about the potential role of platinum and copper atoms in dehydrocyclization.
Structural and chemical characteristics and maturation of the calcium-phosphate crystals formed during the calcification of the organic matrix synthesized by chicken osteoblasts in cell culture

The calcium-phosphate (CA-P) crystals formed in the extracellular organic matrix synthesized by chicken osteoblasts in cell culture were examined after 30, 40, and 60 days of culture by a number of physical and chemical techniques including chemical analyses, X-ray diffraction, transmission electron microscopy of isolated crystals, and resolution-enhanced Fourier transform infrared spectroscopy. The data reveal that the solid inorganic calcium-phosphate phase consists of a very poorly crystalline apatite, having a low carbonate content and containing acid phosphate groups. The chemical and structural characteristics are generally similar to the apatite crystals found in young newly synthesized bone but there were small but significant differences found. The major significant differences noted were the rate at which maturational changes occurred in the crystals formed in cell culture compared with those noted in vivo and in synthetic carbonate apatite crystals equilibrated with the same cell culture medium, and the persistence of labile groups, especially HPO4(-2) ions during a relatively long period of incubation. Despite extensive chemical efforts to degrade the organic constituents and to disperse the individual crystals isolated from the organic matrix constituents, a large proportion of the crystals were found to be organized in both loosely and densely packed relatively large roughly spherical aggregates. A few of the aggregates were organized in the form of fibrils with the crystals oriented with their c-axes roughly parallel to the long axes of the crystal aggregate. With briefer periods of chemical treatment, larger aggregates of crystals were occasionally observed in which there was a distinct axial periodicity of approximately 70 nm. In such collagen-crystal fragments, the crystals were well-oriented with their c-axis roughly parallel to the long axes of the aggregate similar to the organization and relationships between crystals and collagen fibrils in native bone. Isolated crystals were in the shape of thin plates. At the end of 30 days of culture, many of the crystals were clearly larger than those observed in native chick bone, except for those in the very youngest (7- to 8-day-old) embryos. At the end of 40 and 60 days of culture, the crystal habit remained as thin plates but the crystals were predominantly smaller, similar to those found in older embryo and postnatal chicken bone. The marked tendency of the crystals to form relatively large aggregates that resist dispersion by techniques that readily disperse the crystals of bone, and the presence of a significant number of larger crystals has also been observed in studies of calcified cartilage. Resolution enhanced FTIR spectroscopy revealed the presence of a high concentration of labile phosphate groups, especially after 30 days of culture and just after the plateau of mineralization is reached.
Isolated cavernous sinus extramedullary relapse of chronic myelogenous leukemia following allogeneic stem cell transplant

Isolated extramedullary relapse of chronic myelogenous leukemia (CML) after allogeneic stem cell transplant is rare. A case is reported of a patient who developed a granulocytic sarcoma of the cavernous sinus 7 months after allogeneic transplant for CML. He presented with neurologic deficits, and a mass lesion was found on imaging. No evidence of hematologic relapse was identified by bone marrow histology or cytogenetics. A premortem diagnosis was not possible, and the patient died 2 months later of an intracerebral hemorrhage after receiving various therapies directed against a presumed infectious etiology. Granulocytic sarcoma should be considered in the differential diagnosis of mass lesions presenting after allogeneic transplant for CML, even if there is no evidence of medullary disease.
In Vitro Selection of a Deoxyribozyme That Can Utilize Multiple Substrates

Deoxyribozymes that could catalyze the formation of an internucleotide phosphorothioester linkage were selected from a random sequence pool. During the course of the selection, the pool was successively challenged with five oligonucleotide substrates, each of which terminated in the same hexanucleotide sequence. Selected deoxyribozyme ligases could use all five substrates, albeit to different degrees, and appeared to form secondary structures that allow differential pairing between the deoxyribozyme and each substrate. These results suggest that early replicases may have been able to bind a variety of oligonucleotide substrates while catalyzing ligation via a common junction.
How to improve reliability and efficiency of research about molecular markers: roles of phases, guidelines, and study design

Abstract Background and Objective The search for molecular markers for cancer, using “discovery-based” techniques, has resulted in claims of a very high degree of discrimination both for cancer diagnosis (e.g., serum proteomics patterns) and prognosis (e.g., RNA expression genomic signatures). However, many promising initial results have been found to be unreliable or not reproducible, and the larger process of discovery can seem slow and inefficient. To improve the process to develop molecular markers, proposals to use “phases” and “guidelines” have been made, based on experience with the process of drug development and randomized controlled clinical trials. The objective is to help improve the reliability and efficiency of development of molecular markers for cancer diagnosis. Study Design and Setting The literature was searched to identify important current problems (in serum proteomics for cancer diagnosis and RNA expression genomics for cancer prognosis) are identified, and the roles of tools (“phases,” “guidelines,” and “study design”) to address those problems are considered. Based on lessons learned, approaches for the future are discussed, some of which may seem “radical” compared with drug development. Results Phases identify and organize questions to be addressed by individual studies. Guidelines identify features of design and conduct to be reported so that each study's reliability can be judged. Study design involves the myriad details and choices involved in actual planning and conduct of a study. Study design is most important in the sense of determining whether a study is reliable or not. Studies that are unreliable, because of problems from chance and bias, constitute a major current problem leading to inflated expectations, wasted effort, and inefficiency in the larger process of development. By considering fundamental principles, it may be possible to identify approaches that are different than those used in drug development, while preserving reliability and efficiency. Conclusion Phases and guidelines have important roles, but issues in study design address the fundamental problems that compromise reliability and efficiency. Tools to study markers are underdeveloped and will evolve over time, perhaps to include seemingly radical approaches.
The Meanings of tôrâ in 4 Ezra

Torâ, rendered as "the law" in the extant versions, is a central theme of 4 Ezra. The author of 4 Ezra had a much broader concept of torâ than simply the Mosaic law. While for Ezra it is bound up with the covenant, in Uriel's speeches, torâ is a highly abstract concept associated with wisdom, the natural order, and "the way of the Most High." Understanding the term torâ broadly as divine "instruction," the author of 4 Ezra extends it to all of Scripture and by implication to the seventy additional books revealed to Ezra in the epilogue.
The Clausius-Duhem Inequality and the structure of rate-independent plasticity

This paper is concerned with a derivation of the thermodynamic restrictions on a class of inelastic constitutive assumptions that reflect the general response of rate-independent, inelastic materials with a yield condition. The procedure of Coleman and Noll, utilizing the Clausius-Duhem Inequality is used. It is shown that a constitutive statement for the stress and entropy response, similar in form to hyperelastic materials, can be derived from the Clausius-Duhem Inequality without making any special, additional assumptions. The results obtained are well-known in the literature, and have been put to practical use (e.g. numerical implementations of elasto-plastic and damaged materials) in the recent past; it is hoped that this work provides a sound logical basis for the use of such results.
Physical chemistry: handedness detected by microwaves.

Traditional methods for detecting and identifying the handedness of molecules — their chirality — have been based on the same theoretical concept. A technique has been reported that departs from this paradigm. See Letter p.475 Chiral molecules exist as enantiomers that form non-superimposable mirror images, and chirality has a fundamental role in many aspects of chemistry and biology. It is notoriously difficult to detect and quantify chirality because conventional spectroscopic methods exploit weak effects that produce weak signals. Patterson et al. now show that microwave spectroscopy combined with a switched electric field can map the sign of an electric dipole Rabi frequency — a variable that depends directly on the chirality of the molecule — onto the phase of emitted microwave radiation. The effect is then used to determine the chirality of cold gas-phase molecules, illustrated with S and R enantiomers of 1,2-propanediol and their racemic mixture. The method produces large and definitive signatures of chirality, and is both sensitive and species-selective — making it a potentially ideal and unique tool for determining the chirality of multiple species in a mixture.
Drawing inferences from concrete and abstract sentences

A series of three studies employed a sentence verification task with pairs of concrete or abstract sentences. Each test sentence was either a paraphrase or an inference from its corresponding stimulus sentence. The results showed that concrete sentences are verified significantly faster than abstract sentences for both explicit (paraphrase) and implicit (inference) test items, and that paraphrases were verified more rapidly than inferences for both concrete and abstract sentences. There was no reliable interaction between the main effects of explicitness and imageability. These results appear to be consistent across instructional conditions, since they were replicated in Experiment 1 (with an imagery orienting task), Experiment 2 (with a verbal orienting task), and Experiment 3 (which compared both types of tasks). It was concluded that imageability facilitates processing speed for both explicit and implicit aspects of meaning to approximately the same degree.
Risk-taking and contraceptive behavior among unmarried college students.

The contraceptive behavior of sexually active, never-married college women was examined using multiple regression analyses. Use of an effective method of contraception was highly situation-specific: length of relationship and frequency of intercourse were the variables most highly correlated with use of effective contraception, followed by method of contraception used at first coitus and knowledge of reproduction. Failure to use effective contraception was not associated with low estimates of pregnancy risk, nor with high utility of pregnancy, nor with uniquely high willingness to seek abortion. The results of the present study suggest that use or non-use of effective contraception is mediated by the predictability of sexual intercourse.
The BØ Low-Beta Insertion Design for the Tevatron

The low design of the low-beta insertion installed at the BO straight section of the Tevatron is presented. This design replaces two of the regular lattice quadrupoles with stronger, separately powered quadrupoles and adds an additional triplet in the free space on either side of the interaction point. By varying the four separate quadrupole circuits, and two trim quadrupole tuning circuits, it is possible to go smoothly from the normal, fixed-target configuration with s* = 75 m in each plane to the colliding-beam mode of operation with s* = 1 m in each plane, while maintaining a constant tune for the Tevatron.
Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

Historically, the term ‘keratin’ stood for all of the proteins extracted from skin modifications, such as horns, claws and hooves. Subsequently, it was realized that this keratin is actually a mixture of keratins, keratin filament-associated proteins and other proteins, such as enzymes. Keratins were then defined as certain filament-forming proteins with specific physicochemical properties and extracted from the cornified layer of the epidermis, whereas those filament-forming proteins that were extracted from the living layers of the epidermis were grouped as ‘prekeratins’ or ‘cytokeratins’. Currently, the term ‘keratin’ covers all intermediate filament-forming proteins with specific physicochemical properties and produced in any vertebrate epithelia. Similarly, the nomenclature of epithelia as cornified, keratinized or non-keratinized is based historically on the notion that only the epidermis of skin modifications such as horns, claws and hooves is cornified, that the non-modified epidermis is a keratinized stratified epithelium, and that all other stratified and non-stratified epithelia are non-keratinized epithelia. At this point in time, the concepts of keratins and of keratinized or cornified epithelia need clarification and revision concerning the structure and function of keratin and keratin filaments in various epithelia of different species, as well as of keratin genes and their modifications, in view of recent research, such as the sequencing of keratin proteins and their genes, cell culture, transfection of epithelial cells, immunohistochemistry and immunoblotting. Recently, new functions of keratins and keratin filaments in cell signaling and intracellular vesicle transport have been discovered. It is currently understood that all stratified epithelia are keratinized and that some of these keratinized stratified epithelia cornify by forming a Stratum corneum. The processes of keratinization and cornification in skin modifications are different especially with respect to the keratins that are produced. Future research in keratins will provide a better understanding of the processes of keratinization and cornification of stratified epithelia, including those of skin modifications, of the adaptability of epithelia in general, of skin diseases, and of the changes in structure and function of epithelia in the course of evolution. This review focuses on keratins and keratin filaments in mammalian tissue but keratins in the tissues of some other vertebrates are also considered.
Toxicity factors in acidic forest soils: attempts to evaluate separately the toxic effects of excessive Al3+ and H+ and insufficient Ca2+ and Mg2+ upon root elongation

Summary The acidic soils of temperate forests and some pastures on former forest land characteristically contain large amounts of aluminium and hydrogen ions and small amounts of calcium and magnesium ions. The relative importance of these potential toxicity factors are assessed from published data from soils collected in the United States and Europe. Activities of ions in the soil solutions and at the surfaces of root-cell plasma membranes were computed with electrostatic models. Activities of Al3+ in soil solutions ({Al3+}) peaked at pH 4.1, and Al3+ activities at the surface of the plasma membrane ({Al3+}0) achieved a broad maximum between pH 4.1 and 4.8; thus, Al3+ intoxication is likely to be more severe in soils at pH 4.1 than in more acidic ones. Intoxication (assessed by root elongation) correlated somewhat ambiguously with ion activities, but Al3+- and H+-induced depletion of Ca2+ and Mg2+, or both, from the cell surface appears to play a role in toxicity. By contrast, experiments in solution culture, where intercorrelation among {Al3+}, {H+}, and {Ca2+} could be avoided, clearly demonstrated the following extrinsic and intrinsic effects. 1 The ions Al3+ and H+ are intrinsic toxicants. 2 They are also extrinsic toxicants because of the electrostatic displacement of Ca2+ from the surface of the plasma membrane. 3 They are extrinsic ameliorants because each electrostatically displaces the other from the surface of the plasma membrane. 4 The ion Ca2+ is an extrinsic ameliorant because of the electrostatic displacement of Al3+ and H+ from the surface of the plasma membrane. 5 It is an intrinsic ameliorant of intrinsic H+ toxicity, but not intrinsic Al3+ toxicity. 6 It meets an intrinsic requirement. 7 The ion Mg2+ resembles Ca2+ in item 4 but not items 5 and 6 in short-term cultures. In acidic soils, Al3+ may prevent H+ from becoming an intrinsic toxicant (item 3) and may induce an insufficiency of Ca2+ and Mg2+ (item 2). These findings have implications for the mechanisms by which woodland plants tolerate very acidic soils.
Birds and prehistoric agriculture: The New Mexican pueblos

Analysis of faunal remains from prehistoric southwestern pueblo sites reveals certain commonly occurring species of mammals and birds, the latter including ducks and geese, hawks and eagles, American Kestrel, Mourning Dove, owls, Horned Lark, Common Raven, and jays. This phenomenon is examined with the analysis of bird bones from four New Mexican pueblos located in north-central and west-central New Mexico. Recovered faunal remains date to specific periods between A.D. 1250 and the present. Over 70 species of birds represent various ecological situations; many of these species presently do not occur near the pueblos and a few occur only in the extreme southeastern portion of the state. Marsh and riparian areas along the river systems and richer grasslands on the floodplains would account for most of these species occurring near the sites prehistorically. However, rather than attribute unusual species to climatic change, trade, or long-distance hunting expeditions by the Indians, an alternative explanation is offered which attributes high species diversity to areas of human disturbance. Disturbed areas such as agricultural fields can increase species diversity in an area and aid in the range extension of many animals. The primary factor in this situation, besides the crops themselves, is believed to be insects, which attract other animals, particularly birds and their predators. In addition, field irrigation systems act to extend riparian growth from the river across the floodplain, creating habitats for these animals. Finally, certain groups of birds and mammals have developed a natural attraction to human settlements and agricultural areas and these include species whose remains commonly occur in prehistoric pueblo sites. The avifauna from these sites also reveals information on the prehistoric use of birds as inferred from bone modification, cut marks, burials, and articulated wings.
The purine 2-amino group as the critical recognition element for sequence-specific alkylation and cross-linking of DNA by mitomycin C

Mitomycin C (MC) is a G·C-specific antitumor antibiotic that alkylates and cross-links DNA at 2-amino groups of guanine residues. Both reactions are known to be enhanced at guanines in the CpG sequ...
Functional status assessment in the preoperative evaluation of older adults.

MANY COMMON SURGICAL PROCEDURES SUCH AS spinal fusion, coronary artery bypass grafting, and arthroplasty are routinely performed on older adults. Although such procedures can enhance quality and duration of life, adverse events related to the procedure and postoperative period are key considerations. Important complications include delirium, infection, and cardiac events. Development of these and other complications are associated with increased length of stay, increased rate of discharge to chronic care facilities, and increased mortality. Although age has been considered a primary predictor of surgical outcomes, preoperative functional status is likely a better surrogate for postoperative risk. Delirium is a major concern for older patients. Although risk factors for postoperative delirium are well defined, relatively few patients receive targeted interventions for prevention. If preoperative evaluation helped identify patients with poor functional status (cognitive and physical impairment predicts delirium), these individuals might benefit from specific environmental and pharmacologic interventions. Although some institutions have addressed delirium prevention in a proactive, multidisciplinary manner, wide-scale implementation lags. Another important complication is surgical site infection (SSI). Besides increases in length of stay and health care costs associated with SSI, treatment can require additional surgical procedures and extended antimicrobial therapy. The resulting immobility often contributes to poor functional outcomes, thereby potentially reducing any palliative benefit of surgery. Even though age has been recognized as a risk factor for infection, the association has traditionally been attributed to immune senescence and patient comorbidities. Compelling evidence for a link between impaired functional status and SSI was recently demonstrated by Anderson et al, who reviewed 141 345 operative procedures, examining risk factors for the development of methicillin-resistant Staphylococcus aureus (MRSA) SSI. The need for assistance with 3 or more activities of daily living (ADLs) was independently associated with an increased risk of MRSA SSI, an association that persisted after stratifying patients by age. Despite increasing evidence suggesting that impaired functional status is associated with poor postoperative outcomes, the exact connection remains elusive. For instance, development of MRSA SSI is often preceded by MRSA colonization. Yet among older adults who develop SSI, it is unclear whether these patients are colonized with MRSA prior to their operation because of previous health care exposure or whether poor functional status results in increased length of stay and MRSA exposure postoperatively. Although decolonization strategies have been explored for SSI prevention, randomized studies have failed to show consistent benefit. As the number of older adults undergoing major operative procedures continues to increase, several critical changes must occur to address the care needs of this expanding population.
Dopamine D2 Receptor Effects on GABAA Receptor Expression May Modify Melanotrope Peptide Release

Stimulation of melanotrope dopamine D2 receptors decreases mitotic rate, calcium channel activity, and the biosynthesis of several proteins. This study demonstrates that D2 receptor activation also affects GABA(A) receptor beta2/beta3 subunit immunoreactivity. Following chronic treatment with haloperidol, a D2 receptor antagonist, GABA(A) receptor immunoreactivity increased, whereas it decreased after chronic treatment with bromocriptine, a dopamine D2 receptor agonist. Thus, these data indicate that D2 function regulates GABA(A) receptor expression in melanotropes, a mechanism by which peptide release may be modified.