cssi/SciSciGPT-SciSciNet huggingface dataset:
Melanoma, a tumor based on a mutant stem cell?

Stem cells play a critical role in normal tissue maintenance, and mutations in these stem cells may give rise to cancer. We hypothesize that melanoma develops from a mutated stem cell and therefore residual stem cell characteristics should be able to be identified in melanoma cell lines. We studied three metastatic melanoma cell lines that exhibited multiple morphologic forms in culture and demonstrated the capacity to pigment. We used the ability to efflux Hoechst 33342 dye, a technique known to enrich for stem cells in many tissues, to segregate cell populations. The cells with the greatest ability to efflux the dye were (1) small in size, (2) had the capacity to give rise to larger cell forms, and (3) had the greatest ability to expand in culture. The small cells were found to have a decreased proliferative rate and were less melanized. Large dendritic cells that appeared to be nonproliferative were identified in cultures. Treatment with cytosine β-D-arabinofuranoside hydrochloride (Ara-C) expanded the large cell population but the residual proliferative capacity, both in vitro and in vivo, remained concentrated in the smaller cell fraction. Antigenic staining patterns were variable and heterogeneous. Nestin (a neural stem cell marker) and gp100 (premelanosomal marker) favored the smaller cell population, while nerve growth factor receptor often labeled larger cells. Morphologic and antigenic heterogeneity remained intact after clonal purification. These findings are consistent with the behavior expected for a tumor based on stem cell biology; this finding has diagnostic and therapeutic implications for melanocytic neoplasias.
Clinical accuracy and reproducibility of Portrait 3D Surgical Simulation Platform in breast augmentation.

Background: Three-dimensional (3D) digital photography uses integrated image capture technology and rendering software to create 3D models. Volumetric measurements project simulated post-operative images prior to breast augmentation. Objectives: The authors evaluated the accuracy and reproducibility of breast volume measurements using the Portrait 3D Surgical Simulation Platform (Axis Three, Boston, Massachusetts). Methods: Twenty-two patients underwent breast augmentation. 3D volumetric imaging analysis was performed by 2 independent observers preoperatively and at 6 weeks postoperatively. Simulated volumes were compared to actual implant volume using the Student's t test. Intra-observer reliability was measured by internal consistency (Cronbach and 95% confidence interval [CI]) and test-retest reliability (intraclass correlation coefficient [ICC]) from the 2 observers' calculated volumes. Results: Half (n = 11) of the patients received silicone implants and half saline; all were placed in the submuscular plane through an inframammary incision. No difference in volume estimation in preoperative or postoperative images ( P = .49 and P = .14; and P = 1.0 and P = .37, in right and left breasts, respectively) was observed. The test-retest reliability between observers was excellent (ICC, 0.98; P < .001) and Cronbach's value (0.99; 95% CI 0.97–0.99; P < .001) demonstrated an excellent correlation. Regarding accuracy, difference in volume estimation between actual and simulated volumes varied between 0 to 106 mL (0 - 30%), with an absolute mean difference of 12.2% (42.5 mL). Conclusions: The Portrait 3D breast imaging system provides a highly reproducible 3D tool for measuring breast volume and simulating breast augmentation. Accuracy of the 3D models can vary up to 30% (mean 12.2%). This variability should be accounted for when using this technology to visually communicate with patients.
Mutagenicity of three disinfection by-products: di- and trichloroacetic acid and chloral hydrate in L5178Y/TK +/- (-)3.7.2C mouse lymphoma cells.

Abstract The disinfection of water, required to make it safe for human consumption, leads to the presence of halogenated organic compounds. Three of these carcinogenic `disinfection by-products', dichloroacetic acid (DCA), trichloroacetic acid (TCA) and chloral hydrate (CH) have been widely evaluated for their potential toxicity. The mechanism(s) by which they exert their activity and the steps in the etiology of the cancers that they induce are important pieces of information that are required to develop valid biologically-based quantitative models for risk assessment. Determining whether these chemicals induce tumors by genotoxic or nongenotoxic mechanisms (or a combination of both) is key to this evaluation. We evaluated these three chemicals for their potential to induce micronuclei and aberrations as well as mutations in L5178Y/TK+/− −3.7.2C mouse lymphoma cells. TCA was mutagenic (only with S9 activation) and is one of the least potent mutagens that we have evaluated. Likewise, CH was a very weak mutagen. DCA was weakly mutagenic, with a potency (no. of induced mutants/μg of chemical) similar to (but less than) ethylmethanesulfonate (EMS), a classic mutagen. When our information is combined with that from other studies, it seems reasonable to postulate that mutational events are involved in the etiology of the observed mouse liver tumors induced by DCA at drinking water doses of 0.5 to 3.5 g/l, and perhaps chloral hydrate at a drinking water dose of 1 g/l. The weight-of-evidence for TCA suggest that it is less likely to be a mutagenic carcinogen. However, given the fact that DCA is a weak mutagen in the present and all of the published studies, it seems unlikely that it would be mutagenic (or possibly carcinogenic) at the levels seen in finished drinking water.
Self-affine nature of dielectric-breakdown model clusters in a cylinder.

Clusters grown with the dielectric-breakdown model (DBM) in cylinder geometry show two growth phases: a scaling regime for cluster heights smaller than the cylinder circumference and a subsequent steady state, which is translationally invariant in the main growth direction. By studying a very simple, exactly solvable growth model involving arrays of sticks, we arrive at an affine framework, suitably describing the scale invariance of its clusters in the scaling regime. Within this framework we derive new relations between various exponents, which are expected to also hold for DBM clusters. Numerical work on DBM in the scaling regime is presented, indicating that the clusters are indeed self-affine in this phase.
Corrosion Study of Super Ferritic Stainless Steel UNS S44660 (26Cr-3Ni-3Mo) and Several Other Stainless Steel Grades (UNS S31603, S32101, and S32205) in Caustic Solution Containing Sodium Sulfide

Electrochemical techniques, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used in this study to show how the corrosion mechanism of several commercial grades of stainless steel in hot caustic solution is strongly influenced by the presence of sodium sulfide. Experimental results from super ferritic stainless steel UNS S44660 (26Cr-3Ni-3Mo) were compared to austenitic stainless steel UNS S31603, lean duplex stainless steel (DSS) UNS S32101, and standard DSS UNS S32205 in caustic solution, with and without sodium sulfide, at 443 K (170 °C). Weight loss measurements indicated that corrosion rates of UNS44660 were much lower than the other grades of stainless steel in the presence of the sodium sulfide. Potentiodynamic polarization and linear polarization resistance measurements showed that the electrochemical behavior was altered by the adhesion of sulfur species, which reduced the polarization resistances and increased the anodic current densities. SEM and XPS results imply that the surface films that formed in caustic solution containing sodium sulfide were defective due to the adsorption of sulfide, which destabilized the passive film and led to the formation of insoluble metal sulfide compounds.
Sterol metabolism. XI. Thermal decomposition of some cholesterol hydroperoxides.

Summary The decomposition of cholesterol 20α- and 25-hydroperoxides was studied by gas chromatography. Cholesterol 20α-hydroperoxide decomposed to 3β-hydroxypregn-5-en-20-one, androst-5-en-3β-ol, cholest-5-ene-3β, 20α-diol, androst-5-ene-3β, 17β-diol, and androsta-5,16-dien-3β-ol. Cholesterol 25-hydroperoxide decomposed to cholest-5-ene-3β, 25-diol, chol-5-en-3β-ol, pregn-5-en-3β-ol, and 3β-hydroxy-27-norcholest-5-en-25-one. These thermal decomposition patterns, similar to but different from that of autoxidation products in air-aged cholesterol, account suitably for the presence of degraded steroids in air-aged cholesterol. Analogies are drawn between the autoxidation of cholesterol via hydroperoxide intermediates with subsequent spontaneous decomposition and the biological oxidation of cholesterol to give similar types of products.
Functional mixed effects spectral analysis.

In many experiments, time series data can be collected from multiple units and multiple time series segments can be collected from the same unit. This article introduces a mixed effects Cramer spectral representation which can be used to model the effects of design covariates on the second-order power spectrum while accounting for potential correlations among the time series segments collected from the same unit. The transfer function is composed of a deterministic component to account for the population-average effects and a random component to account for the unit-specific deviations. The resulting log-spectrum has a functional mixed effects representation where both the fixed effects and random effects are functions in the frequency domain. It is shown that, when the replicate-specific spectra are smooth, the log-periodograms converge to a functional mixed effects model. A data-driven iterative estimation procedure is offered for the periodic smoothing spline estimation of the fixed effects, penalized estimation of the functional covariance of the random effects, and unit-specific random effects prediction via the best linear unbiased predictor.
Sex Differences in the Eyes of Expert Personality Assessors: Blind Spots?

Summary Sex differences in rating performances with the 100-item California Q Sort are reported for 10 men and 13 women psychologists who were variously paired to assess the adult personalities of the same 48 male and 50 female Ss. Women judges ascribe more favorable characteristics to females than do men, while men judges are generally more unfavorable in their judgments of both men and women. Other qualitative differences, perhaps related to stereotypic sex-role perceptions, are discussed. The absence of empirical data on sex differences to expert judgment is noted, and the need for control of this factor in future accessment studies is indicated.
The synthesis and structure of a new zirconium iodide carbide cluster phase, Cs2Zr7I18C

Abstract The title compound is obtained from reactions of CsI, ZrI 4 , Zr, and C in sealed Ta at 800°C (but not at 850°C). Both Zr 6 I 12 C and Zr 6 I 14 C are unstable in the presence of CsI. The Cs 2 Zr 7 I 18 C is shown by X-ray crystallography to be isostructural with K 2 Zr 7 Cl 18 H and is better described as Cs 2 ZrI 6 · Zr 6 I 12 C, the iodine in the ZrI 2- 6 groups bonding to metal vertices in six separate carbon-centered clusters (R3, Z = 3 for a = 10.744(1) A, c = 29.409(5) A, R ( F )/ R w = 3.5/4.4%).
Shack-Hartmann wavefront sensing performance evaluation for active correction of the Large Synoptic Survey Telescope (LSST)

The Large Synoptic Survey Telescope will map out the dark matter in the universe and is scheduled to see "first light" in 2014. This telescope will require active correction of its mirrors to remove the aberrations that arise from changing gravitational force vectors and from thermal drifts in the telescope during observational runs. In this article we present a comprehensive evaluation of a Shack-Hartmann wavefront sensor and reconstruction algorithm which is capable of meeting the unique challenges associated with this wide field-of-view survey telescope. The advantages of this technique over other potential wavefront sensing technologies are discussed and the potential problems encountered with this approach are analyzed and solutions to these problems presented.
Distortions of normal bone cell metabolism induced in multiple myeloma

Abstract Samples of bone marrow infiltrated with myeloma cells derived from iliac crest biopsies taken from 12 patients with multiple myeloma were studied in vitro in an attempt to discover the cause of the bone lesions characteristic of the disease. The relative affinities of the two cell types for glucose and proline were examined and found to be similar making inhibition of bone matrix biosynthesis due to competion for substrate unlikely as a cause for bone destruction. Measurements of incorporation of proline into bone cells and matrix revealed increased retention of label in cells (seemingly in a macromolecule) but generally normal incorporation into collagen. Parallel studies of myelomatous marrow suggested that these changes involved a change in bone cell metabolism per se and were not the result of marrow contamination. Collagenase activity was normal or low in the bone cells of four patients and virtually absent from marrow and plasmacytomas, thus ruling out abnormal biosynthesis of collagenase as a cause of bone destruction. These data are interpreted as indicating a redirection and stimulation of bone cell biosynthetic mechanisms as a result of the invasion of the marrow by Myeloma cells. The nature of the material (presumed to be protein) made is unknown.
Learning from history: Low-cost project innovation in the U.S. National Aeronautics and Space Administration

Abstract Beginning in 1992, officials in the U.S. National Aeronautics and Space Administration (NASA) undertook a concerted effort to conduct a series of low-cost space exploration missions. Initially, the approach worked well. The effort fell into disfavor after a succession of mission failures between 1999 and 2002. Following those failures, NASA officials returned to a more traditional systems management approach for the next set of projects in the low-cost line. Based on an analysis of thirty-one projects with launch dates between 1992 and 2008, this article provides a history of NASA's experience with low-cost innovation. It suggests that both the initial team-based approach and the systems management approach have merit so long as managers pay close attention to the requirements each approach imposes. Analysis further suggests that the troubled projects suffered from a misapplication of management techniques developed for the team-based approach.
Major Concerns of Women After Cesarean Delivery

Abstract Objective To identify women's major physiologic, psychologic, and life-style concerns at 2 and 8 weeks after cesarean delivery. Design Descriptive study with open-ended interviews. Setting: Large urban hospital affiliated with a major university. Participants One hundred six women who had unplanned cesarean deliveries and delivered live, full-term neonates. The mean maternal age was 28.7years. Main Outcome Measures The major physiologic, psychologic, and life-style concerns. Results Seven women reported no concerns at both data points. The number of physiologic concerns that the women expressed decreased markedly from 2 to 8 weeks postdelivery, but the number of psychologic and life-style concerns did not. Conclusions These findings reinforce the need for prenatal teaching and postnatal follow-up regarding these concerns.
Electronic Structure of the Peroxy Intermediate and Its Correlation to the Native Intermediate in the Multicopper Oxidases: Insights into the Reductive Cleavage of the O-O Bond

The multicopper oxidases (MCOs) utilize a blue type 1 (T1) copper site and a trinuclear Cu cluster composed of a type 2 (T2) and a binuclear type 3 (T3) site that together catalyze the four-electron reduction of O2 to H2O. Reaction of the fully reduced enzyme with O2 proceeds via two sequential two-electron steps generating the peroxy intermediate (PI) and the native intermediate (NI). While a detailed description of the geometric and electronic structure of NI has been developed, this has been more elusive for PI largely due to the diamagnetic nature of its ground state. Density functional theory (DFT) calculations have been used to correlate to spectroscopic data to generate a description of the geometric and electronic structure of PI. A highly conserved carboxylate residue near the T2 site is found to play a critical role in stabilizing the PI structure, which induces oxidation of the T2 and one T3 Cu center and strong superexchange stabilization via the peroxide bridge, allowing irreversible binding ...
X-ray Crystal Structures of HMG-CoA Synthase from Enterococcus faecalis and a Complex with Its Second Substrate/Inhibitor Acetoacetyl-CoA†,‡

Biosynthesis of the isoprenoid precursor, isopentenyl diphosphate, is a critical function in all independently living organisms. There are two major pathways for this synthesis, the non-mevalonate pathway found in most eubacteria and the mevalonate pathway found in animal cells and a number of pathogenic bacteria. An early step in this pathway is the condensation of acetyl-CoA and acetoacetyl-CoA into HMG-CoA, catalyzed by the enzyme HMG-CoA synthase. To explore the possibility of a small molecule inhibitor of the enzyme functioning as a non-cell wall antibiotic, the structure of HMG-CoA synthase from Enterococcus faecalis (MVAS) was determined by selenomethionine MAD phasing to 2.4 A and the enzyme complexed with its second substrate, acetoacetyl-CoA, to 1.9 A. These structures show that HMG-CoA synthase from Enterococcus is a member of the family of thiolase fold enzymes and, while similar to the recently published HMG-CoA synthase structures from Staphylococcus aureus, exhibit significant differences in the structure of the C-terminal domain. The acetoacetyl-CoA binary structure demonstrates reduced coenzyme A and acetoacetate covalently bound to the active site cysteine through a thioester bond. This is consistent with the kinetics of the reaction that have shown acetoacetyl-CoA to be a potent inhibitor of the overall reaction, and provides a starting point in the search for a small molecule inhibitor.
A Simulation of Labor Efficiency and Centralized Assignment in a Production Model

This paper reports a set of simulation experiments with a service system model in which labor interchange is possible between service centers. It explores design and control aspects of labor and machine limited systems. A simple model with two service centers and two laborers is employed to explore the relationships among three experimental variables. The variables are the efficiency of labor interchange, the degree of centralized control exercised in labor assignment, and the queue discipline. Both series and job-shop type job routings are studied.
Fertility-sparing radical abdominal trachelectomy for cervical carcinoma.

A laparotomy and a bilateral complete pelvic lymphadenectomy are performed usually via a transverse lower abdominal incision in a similar manner to patients undergoing a radical abdominal hysterectomy. The limits of nodal dissection are the deep circumflex iliac vein caudally and the proximal common iliac artery cephalad. Any suspicious lymph nodes are sent for frozen-section analysis. A fertility-sparing approach should be abandoned if positive lymph nodes are identified. Sentinel lymph node identification is also a reasonable option and may allow for pathologic ultra-staging of these sentinel nodes. The removal of paraaortic nodes is also considered for lesions stage IB1 or greater. The intent of the radical abdominal trachelectomy is to resect the cervix, upper 1–2 cm of the vagina, parametrium, and paracolpos in a similar manner to a type III radical abdominal hysterectomy but sparing the uterine fundus or corpus (Figs. 1 and 2).
Blood flow to organs: parameters for function and survival in critical illness.

Tissues are usually considered as being supply-dependent (e.g., heart and brain) and supply-independent (e.g., splanchnic area, kidneys, skin, and resting muscle) for oxygen delivery. When cardiovascular function is compromised, circulatory compensations are aimed at maintaining supply-dependent tissues. In the long term, this leads to the possibility of an inadequate blood flow to supply independent tissues. The perfusion maintenance of all organs requires adequate cardiac output, blood volume, and arterial BP. When BP and cardiac output fail, regional perfusion diminishes. Although the human system tolerates anemia well, optimum Hct levels are probably between 30% to 40%. Inadequate perfusion can be supplemented partially by increasing the FIO2 on a temporary basis. Hyperoxic arterial oxygen tensions may cause maldistribution of blood flow within organs.
A Fundamental Study and Modeling of the Micro-Droplet Formation Process in Near-Field Electrohydrodynamic Jet Printing

Near-field electrohydrodynamic jet (E-jet) printing has recently gained significant interest within the manufacturing research community because of its ability to produce micro/submicron-scale droplets using a wide variety of inks and substrates. However, the process currently operates in open-loop and as a result suffers from unpredictable printing quality. The use of physics-based, control-oriented process models is expected to enable closed-loop control of this printing technique. The objective of this research is to perform a fundamental study of the substrate-side droplet shape-evolution in near-field E-jet printing and to develop a physics-based model of the same that links input parameters such as voltage magnitude and ink properties to the height and diameter of the printed droplet. In order to achieve this objective, a synchronized high-speed imaging and substrate-side current-detection system is implemented to enable a correlation between the droplet shape parameters and the measured current signal. The experimental data reveals characteristic process signatures and droplet spreading regimes. The results of these studies served as the basis for a model that uses the measured current signal as its input to predict the final droplet diameter and height. A unique scaling factor based on the measured current signal is used in this model instead of relying on empirical scaling laws found in prior E-jet literature. For each of the three inks tested in this study, the average error in the model predictions is under 10% for both the diameter and the height of the steady-state droplet. While printing under nonconducive ambient conditions of low relative humidity and high temperature, the use of the environmental correction factor in the model is seen to result in a 17% reduction in the model prediction error.
Temporal species richness-biomass relationships along successional gradients

Diversity-biomass relationships are frequently re- ported to be hump-shaped over space at a given time. How- ever, it is not yet clear how diversity and biomass change simultaneously and how they are related to each other over time (e.g. in succession) at one locality. This study develops a temporal model based on the projected changes of various community variables in a generalized terrestrial environ- ment after fire and uses post-fire succession data on Santa Monica Mountains of southern California and other pub- lished succession data to examine the temporal diversity- biomass relationships. The results indicate that in the early stages of succession, both diversity and biomass increase and a positive relationship appears, while in the late stages of succession, biomass continued to increase but diversity usu- ally declines; thus a negative relationship may be observed. When the scales of measurement become sufficiently large so that the measured diversity and biomass cross various stages of succession, a 'hump-shaped' relationship can emerge. The diversity-biomass relationship appears to be concordant in space and time when appropriate scales are used. Formerly proposed explanations for spatial patterns may well apply to the temporal patterns (particularly colonization, facilitation and competitive exclusion).
Mitochondrial DNA Mutations Cause Disease, Apoptosis, and Permeability Transition Pore Dysfunction.

INTRODUCTION. Mitochondrial DNA (mtDNA) mutations accumulate with age (1), but are normally below the level of 1%. It is unlikely that respiratory deficiencies result from such low frequencies; indeed, we recently showed that respiratory function was preserved in mice with somatic mtDNA mutations in the heart, despite induction of severe cardiomyopathy (2). Therefore, mutations may need to invoke a dominant mechanism of dysfunction. We showed that one such mechanism, oxidative stress, was not the cause of the myopathy (3). Here we describe a second dominant mechanism, the activation of apoptosis, cytochrome c release, and permeability transition pore dysfunction. We propose that malfolded mutant mitochondrial proteins alter mitochondrial permeability by interacting with cyclophilin D, a bi-functional protein that acts as a protein-folding catalyst and as a regulator of the permeability transition pore.
The early detection of colorectal cancer.

A review of the American Cancer Society's statistics for colorectal cancer indicates that there has been little improvement in the survival rate for this disease in the past 25 years. Although there have been advances in surgical techniques, radiation therapy, and chemotherapy, the key to improved survival rates is earlier diagnosis. A significant percentage of patients continues to present with regional or distal metastasis at the time of their initial diagnosis. Both procosigmiodoscopy and guaiac impregnated filter slide paper methods have been productive in diagnosing this disease at an earlier stage. The “Hemoccult” test, however, is inexpensive, can be used on a routine basis, is easier for patients to perform themselves, and is aesthetically pleasing. It represents a significant cost savings compared to proctosigmiodoscopy and should be advocated for routine use in all patients over 40 years of age. Although there continues to be a role for local and regional mass screening programs, significant imporvements in colorectal survival rates cannot be expected until routine application of this type of screening is practiced. Cancer 40:945–949, 1977.
A new species of Late Pleistocene rail (Aves: Rallidae) from Abaco, the Bahamas

We describe a new species of rail from the Sawmill Sink blue hole on Abaco Island in the northern Bahamas. Known from abundant, beautifully preserved Late Pleistocene fossils, Rallus cyanocavi sp. nov. was a medium-sized, flightless species that probably was endemic to the Little Bahama Bank, which is a carbonate platform surrounded by deeper water. We are uncertain whether R. cyanocavi survived into the Holocene, when higher sea levels transformed the Little Bahama Bank from a single large, Late Pleistocene island (ca. 12000 km2) to the scattering of smaller islands seen today, the largest of which is Abaco (1681 km2). Fossils of additional extinct, flightless species of Rallus probably await discovery on some of the 21 other carbonate banks that span the Bahamian Archipelago.
Does habituation affect fingerprint quality

Interest in the environmental factors that affect biometric image quality is increasing as biometric technologies are currently being implemented in various business applications. This study aims to determine, through repeated trials, the effects of various external factors on the image quality and usability of prints collected by an electronic reader. These factors include age and gender but also the absence or presence of immediate feedback. A key factor in biometric systems that will be used daily or routinely is habituation. The user's behavior could potentially change as a result of acclimatization; one's input might increase in quality as one learns how to use the system better, or decrease in quality since comfort with the system could translate into carelessness.
SU(2) gauge symmetry and anomaly of the S = {1}/{2} antiferromagnetic Heisenberg model in 2 + 1 dimensions

Abstract On the basis of the local SU (2) symmetry of the Heisenberg model, we show that the model, in a continuum limit, reduces to a problem of massless fermions coupled to an SU(2) gauge field in three space-time dimensions. The effective gauge field action changes by ± π ⦶ n ⦶ under a large gauge transformation with winding number n . To restore the gauge invariance, a parity- nonconserving, topological term is needed in the effective action. The physical implications are conjectured.
Biomedical Assist Devices and New Biomimetic Machines—A Short Perspective

Over the last few decades, new engineering designs have made tremendous impact on the healthcare industry with solutions for diagnosis, treatment, and therapy of a wide range of medical conditions. In recent years, new designs of bio-inspired machines have been proposed for terrestrial and aerial applications. As one would expect, a detailed survey of these areas is impossible to accomplish in a few pages. Hence, this brief survey highlights three topics: (i) Gait rehabilitation machines, (ii) minimal invasive surgical machines, and (iii) flapping wing flying machines.
Calcite Biocomposites Up Close

From echinoderm spines to the exoskeletons of coccolithophores and the prismatic layer structures of mollusk shells, organisms can generate complex and fantastic architectures by depositing minerals such as calcite into matrices containing biomolecules. The biopolymers not only direct the orientation, texture, and morphology of the crystalline network, they are often incorporated within the mineral phase and play integral roles in enhancing mechanical properties ( 1 ). On page [1244][1] of this issue, Li et al. ( 2 ) use electron tomography to demonstrate how physical entrapment of biopolymers leads to the formation of high-energy calcite surfaces at the interfaces with the polymer network. The work paves the way toward a clearer understanding of biogenic and synthetic mineral-polymer composites. [1]: /lookup/doi/10.1126/science.1178583
Porcine aortic endothelial cells activate human T cells: direct presentation of MHC antigens and costimulation by ligands for human CD2 and CD28.

Abstract We examined the human xenoresponse to cultured porcine aortic endothelial cells (PAECs). Human CD8 + T cells proliferate to resting MHC class 1-positive PAECs. CD4 + T cells proliferate after MHC class 11 molecules are induced with swine interferon-γ. These responses are greater than corresponding allogeneic responses to human umbilical vein endothelial cells (HUVECs). Limiting dflution analysis shows a 10-fold higher frequency of xenoreactive than alloreactive anti-endothelial lymphocytes. Species-specific monoclonal antibodies suggest that PAECs directly present swine MHC antigens to human T cells and that human CD4 and CD8 molecules participate M this Interaction. Furthermore, PAECs bind CTLA-4-Ig and costimulate human T cells by both the CD2 and CD28 pathways. In contrast, HUVECs do not bind CTLA-4-Ig and only use the CD2 pathway.
Population antibiotic susceptibility for Streptococcus pneumoniae and treatment outcomes in common respiratory tract infections.

Purpose Antibiotic-resistant Streptococcus pneumoniae potentially threatens the successful treatment of common respiratory tract infections (RTIs); however, the relationship between antibiotic resistance and treatment outcomes remains unclear. We aimed to test the hypothesis that higher in vitro penicillin and erythromycin nonsusceptibility levels among clinical isolates of S. pneumoniae are associated with higher risk of treatment failure in suppurative acute otitis media (AOM), acute sinusitis, and acute exacerbation of chronic bronchitis (AECB). Methods We conducted a population-level analysis using treatment outcomes data from a national, managed-care claims database, and antibiotic susceptibility data from a national repository of antimicrobial susceptibility results between 1997 and 2000. Treatment outcomes in patients with suppurative AOM, acute sinusitis, or AECB receiving selected macrolides or beta-lactams were assessed. Associations between RTI-specific treatment outcomes and antibiotic nonsusceptibility were determined using Spearman correlation coefficients with condition-specific paired outcome and susceptibility data for each region and each year. Results There were 649 552 available RTI outcomes and 7252 susceptibility tests performed on S. pneumoniae isolates. There were no statistically significant trends across time for resolution proportions following treatment by either beta-lactams or macrolides among any of the RTIs. Correlation analyses found no statistically significant association between S. pneumoniae susceptibility and RTI treatment outcomes apart from a significant positive association between of erythromycin nonsusceptibility in ear isolates and macrolide treatment resolution for suppurative AOM. Conclusion On the population level, in vitroS. pneumoniae nonsusceptibility to macrolide or beta-lactam antibiotics was not associated with treatment failure in conditions of probable S. pneumoniae etiology. Copyright © 2005 John Wiley & Sons, Ltd.
A reconfigurable ATM switch fabric for fault tolerance and traffic balancing

A large-scale asynchronous transfer mode (ATM) switch fabric that can be constructed with currently feasible technology is proposed. Based on analysis of the technology, it is found that module interconnection becomes the bottleneck for a large fast packet switch. Fault tolerance for the switch is achieved by dynamic reconfiguration of the module interconnection network. The design improves system reliability with relatively low hardware overhead. An abstract model of the replacement problem for the design is presented, and the problem is transformed into a well-known assignment problem. The maximum fault tolerance is found, and a fast replacement algorithm is given. The reconfiguration capability can also be used to ameliorate imbalanced traffic flows. The authors formulate this traffic flow assignment problem for the switch fabric and show that the problem is NP-hard. A simple heuristic algorithm is proposed, and an example is given. >
Measuring and maximizing coverage in the World Trade Center Health Registry

The World Trade Center Health Registry (WTCHR) is a database for following people who were exposed to the disaster of 11 September 2001. Hundreds of thousands of people were exposed to the immense cloud of dust and debris, the indoor dust, the fumes from persistent fires, and the mental trauma of the terrorist attacks on the WTC on 9/11. The purpose of the WTCHR is to evaluate the potential short- and long-term physical and mental health effects of the disaster. The definitions of the exposed groups are broad and defined based on an understanding of which groups had the highest exposures to the WTC disaster and its aftermath. The four exposure groups include rescue and recovery workers, residents, students and school staff, and building occupants and passersby in Lower Manhattan. While one goal of the WTCHR was to maximize coverage overall and for each exposure group, another was to ensure equal representation within exposure groups. Because of the multiple sample types pursued, several approaches were required to determine eligibility. Estimates of the number of eligible persons in each of the exposed populations were based on the best available information including Census, entity-specific employment figures, and public and private school enrollment data, among other publicly available sources. To address issues of undercoverage and overcoverage a variety of methods were assessed or applied, including a capture-recapture analyses test of overlapping sample building list sources and automated deduplication of sample records. Estimates of the true eligible population indicate that over 400,000 unique individuals were eligible for the baseline health survey. Interviewer-administered surveys were completed with more than 71,000 persons, resulting in an overall enrollment rate of approximately 17 per cent. Coverage was highest among rescue and recovery workers, followed by residents, students and school staff, and building occupants. Both the accuracy of coverage estimates and the raw number and representativeness of enrollees were maximized by our approach to coverage. In designing a registry which relies on multiple pathways and sources of data to build the sample, it is important to develop a comprehensive approach that considers all sources of error and minimizes bias that may be introduced through the methodology.
CD34+ Autologous Human Stem Cells in Treating Refractory Angina

See related article, pages 428–436 The article by Losordo et al1 in this issue of Circulation Research is an important addition to the relatively small body of literature in clinical cardiac stem cell therapy. Although the number of patients in the trial by Losordo et al is fairly small, only a handful of similarly sized trials have been published.2–4 In the recent past, the merit of performing clinical trials of cardiac cell therapy was debated in the literature.5,6 However, the study of regenerative cardiac medicine continues to move forward, despite the fact that opponents have highlighted the many challenges in the field, focusing mainly on the lack of mechanistic data. Nevertheless, other questions, such as the best cell type, cell dose, and delivery modality, are beginning to be answered. The performance of larger-scale studies is now being proposed. Interestingly, a large phase III trial of autologous bone marrow mononuclear cells (ABMMNCs) is ready to be initiated in Europe (Oral presentation by Anthony Mathur, PhD; June 2011, Eighth International Symposium on Stem Cell Therapy and Cardiovascular Innovations, Madrid, Spain). Most clinical trials in cardiac cell therapy have been performed with ABMMNCs. Although the use of this mixed cell population may be considered a relatively broad or less sophisticated approach, ABMMNCs continue to be used because of the previous success with this approach. However, investigators are also seeking new, possibly more potent cell types in bone marrow subpopulations, such as aldehyde dehydrogenase bright (ALDHbr) cells7 (characterized by a common enzyme), mesenchymal cells (a single bone marrow cell population), or as in the trial by Losordo et al, CD34+ …
Design error diagnosis and correction in VLSI digital circuits

With the increase in the complexity of VLSI circuit design and the corresponding increase in the number of logic gates on a chip, logic design errors can frequently occur. In this paper we present an efficient test-vector simulation approach for design error diagnosis when a small number of modifications can rectify the erroneous design. We also compare the quality of verification and diagnosis that test vector simulation offers for design errors with the one offered by BDDs and show the competitive performance of the former. Experimental results exhibit the robustness of our approach.
Microsatellite primers for the neotropical epiphyte Epidendrum firmum (Orchidaceae).

PREMISE OF THE STUDY Ten microsatellite loci were isolated and characterized for the neotropical epiphytic orchid Epidendrum firmum to examine levels of genetic diversity and genetic structure at multiple spatial scales. METHODS AND RESULTS We screened loci in 12-25 individuals from each of two populations in Costa Rica and identified 10 polymorphic loci. The number of alleles per locus ranged from one to 15 while observed heterozygosity for polymorphic loci ranged from 0.360 to 0.960. CONCLUSIONS Primers for these informative genetic markers will be useful for quantifying genetic diversity, spatial genetic structure, and gene flow in E. firmum.
Liver-specific cytochrome P450 CYP2C22 is a direct target of retinoic acid and a retinoic acid-metabolizing enzyme in rat liver.

Several cytochrome P450 (CYP) enzymes catalyze the C4-hydroxylation of retinoic acid (RA), a potent inducer of cell differentiation and an agent in the treatment of several diseases. Here, we have characterized CYP2C22, a member of the rat CYP2C family with homology to human CYP2C8 and CYP2C9. CYP2C22 was expressed nearly exclusively in hepatocytes, where it was one of the more abundant mRNAs transcripts. In H-4-II-E rat hepatoma cells, CYP2C22 mRNA was upregulated by all-trans (at)-RA, and Am580, a nonmetabolizable analog of at-RA. In comparison, in primary human hepatocytes, at-RA increased CYP2C9 but not CYP2C8 mRNA. Analysis of the CYP2C22 promoter region revealed a RA response element (5 ′ -GGTTCA-(n)5-AGGTCA-3 ′) in the distal flanking region, which bound the nuclear hormone receptors RAR and RXR and which was required for transcriptional activation response of this promoter to RA in CYP2C22-luciferase-transfected RA-treated HepG2 cells. The cDNA-expressed CYP2C22 protein metabolized [3H]at-RA to more polar metabolites. While long-chain polyunsaturated fatty acids competed, 9-cis-RA was a stronger competitor. Our studies demonstrate that CYP2C22 is a high-abundance, retinoid-inducible, hepatic P450 with the potential to metabolize at-RA, providing additional insight into the role of the CYP2C gene family in retinoid homeostasis.
Coronary Endothelial Dysfunction Precedes Heart Failure and Reduction of Coronary Reserve in Awake Dogs

Endothelial dysfunction in coronary circulation is well documented in heart failure (HF). However, whether this dysfunction is a consequence of heart failure or precedes the development of HF remains unknown. To determine endothelium-dependent regulation in the remote coronary vasculature in a canine coronary microembolization-induced HF model, seven dogs were chronically instrumented for measurement of systemic hemodynamics, for selective coronary microembolization via an implanted coronary catheter and for measurement of coronary blood flow in the non-embolized coronary artery. Microembolizations were performed daily until hemodynamic and echocardiographic measurements showed HF. The responses of coronary blood flow to acetylcholine (0.25, 0.5, 5, 10 microg/kg), nitroglycerin (0.2, 0.8, 5, 25 microg/kg), adenosine (0.25, 0.5, 2, 5 micromol/kg) and brief coronary occlusions (5, 10, 15, 20, 30 s) were examined. Although no signs of HF developed and the responses of coronary blood flow to nitroglycerin, adenosine and occlusions were not altered, the response to acetylcholine was selectively reduced after 1 week of embolization (275,000+/-55,000 microspheres). Resting coronary flow increased from 21.3+/-1.4 ml/min in control state to 27.7+3.5 ml/min (P<0.001). As HF developed, characterized by an elevated left ventricular end-diastolic pressure (6.4+/-1.6 v 16+/-1.6 mmHg, P<0.001), a decreased area ejection fraction (54+/-5 v 36+/-5%, P<0.05) and a reduced beta-adrenergic response to isoproterenol, the responses of coronary blood flow to acetylcholine, nitroglycerine, adenosine and occlusions were consistently depressed. Resting coronary blood flow was decreased to 15.4+/-2.7 ml/min (P<0.01). Our results indicate, that there is a selectively impaired endothelium-mediated dilator capacity of the resistance coronary vasculature before the development of HF and a reduction of the coronary flow reserve.
Issues in position estimation of SR motors

Various sources of error inherent to most switched reluctance (SR) motor position estimation schemes are identified, and their effects on estimation accuracy are quantified. Several numerical techniques are explored for their role in reducing the position estimation errors. Design guidelines for various motor design parameters, which can enhance the accuracy of any position estimation algorithm, are also presented.
Micromechanics and Microdynamics Via Atomistic Simulations

Basic understanding of the structure and dynamics of materials and their response to external perturbations requires knowledge on the microscopic level, of the underlying energetics and atomic dynamics, whose consequences we observe and measure. Coupled with the above is the everlasting quest to observe and understand natural phenomena on refined microscopic scales, which provides the impetus for the development of experimental and theoretical techniques for the interrogation of materials with refined spatial and temporal resolution. In this paper we review the development of molecular dynamics simulations for studies of the energetics and dynamical response of materials to external mechanical perturbations. Applications to investigations of solid and liquid interfacial systems under stress and to studies of the consequences of tip-substrate interactions in atomic force microscopy are demonstrated.
Queer Patriarchies, Queer Racisms, International

This paper explores the potential for certain gay white men to benefit from postindustrial sectors that depend structurally and implicitly upon white supremacy and heteropatriarchy. The paper maps out how gay white patriarchies coexist with, and in some cases displace, heteronormative patriarchies, shoring up pre–existing racialized and politically and economically conservative processes of profit–accumulation. Former cultural investments in a fatherhood defined by biological procreation are accordingly dislodged by investments in fatherhoods abstracted from procreation, which circulate in a variety of commodity forms. Motherhood is geographically and socially sidelined, procreation becoming a service and commodity form purchasable from impoverished places within or outside nations. The white oedipal Family romance is geopolitically reconstituted, with the proprietary reach of patriarchy irrupting out of the confines of the biologically homebound and racist triad of mother–father–son and into extrafamilial, and often transnationalized, domains of racialized and class–transected procreational purchase.
Texas Latino Prison Gangs: An Exploration of Generational Shift and Rebellion

This article addresses what many observers of Texas’ prison gangs perceive as significant changes in the hierarchical structure of various Latino groups. Focusing on the state’s central and eastern...
Crystal structures of a ddATP-, ddTTP-, ddCTP, and ddGTP- trapped ternary complex of Klentaq1: insights into nucleotide incorporation and selectivity

The mechanism by which DNA polymerase I enzymes function has been the subject of extensive biochemical and structural studies. We previously determined the structure of a ternary complex of the large fragment of DNA polymerase I from Thermus aquaticus (Klentaq1) bound to a primer/template DNA and a dideoxycytidine 5′-triphosphate (ddCTP). In this report, we present the details of the 2.3-Å resolution crystal structures of three additional ternary complexes of Klentaq1 bound to a primer/template DNA and a dideoxyguanosine 5′-triphosphate (ddGTP), a dideoxythymidine 5′-triphosphate (ddTTP), or a dideoxyadenosine 5′-triphosphate (ddATP). Comparison of the active site of the four ternary complexes reveals that the protein residues around the nascent base pair (that formed between the incoming dideoxynucleoside triphosphate [ddNTP] and the template base) form a snug binding pocket into which only a correct Watson-Crick base pair can fit. Except in the ternary complex bound to dideoxyguanosine 5′-triphosphate, there are no sequence specific contacts between the protein side chains and the nascent base pair, suggesting that steric constraints imposed by the protein onto the nascent base pair is the major contributor to nucleotide selectivity at the polymerase active site. The protein around the polymerase active site also shows plasticity, which may be responsible for the substrate diversity of the enzyme. Two conserved side chains, Q754 and R573, form hydrogen bonds with the N3 atom in the purine base and O2 atom in the pyrimidine base at the minor groove side of the base pair formed by the incorporated ddNMP and the corresponding template base in all the four ternary complexes. These hydrogen-bonding interactions may provide a means of detecting misincorporation at this position.