cssi/SciSciGPT-SciSciNet huggingface dataset:
Is percutaneous insertion of the intra-aortic balloon pump through the femoral artery the safest technique?

Abstract Between Jan. 1, 1979, and Sept. 30, 1983, 423 intra-aortic balloon pumps (IABPs) were successfully inserted into 400 patients; IABPs could not be inserted in 36 patients (success rate 91.7%). Before 1980 all balloons were inserted surgically through a graft and by 1983 virtually all IABPs were inserted by percutaneous techniques. Infectious complications occurred in 12.3% of IABPs inserted by the open technique and 1.5% of IABPs inserted percutaneously (p 0.5) and when only the surviving patients were analyzed (p > 0.75). However, ischemic complications occurred in 32.9% of women in the study and only 19.7% of the men (p
Managing assisted reproduction in women over the age of 50 years: a clinical update

For more than 20 years, women over 50 years of age have been able to achieve pregnancy and deliver babies using donor oocyte IVF (D-IVF). Pregnancy and live-birth delivery rates following D-IVF in these older patients are comparable with rates experienced by younger women undergoing IVF with either donor or autologous oocytes. While there are increased risks of adverse perinatal events occurring in this unique older age group of women, the current data infers the relative overall safety of attempting pregnancy in properly screened and selected patients. This article describes the history and current practice of D-IVF in women over 50 years of age and then concludes with expert commentary and current 5-year outlook on the future of this practice.
ELECTRODE-ASSISTED SOIL WASHING

Contaminants in soils containing a high percentage of silt- and clay-sized particles typically are strongly adsorbed and very difficult to remove. However, a newly patented Electrode Assisted Soil Washing (EASW) process appears to be effective in removing petroleum hydrocarbons (gasoline, diesel, crude oil, etc.), chlorinated hydrocarbons, and heavy metals [7] from contaminated soils made up of a high percentage of clay and silt. The EASW process produces a washed soil material that meets site-specific regulatory requirements which allow the washed soil to be returned to the site without further treatment. Furthermore, the contaminated water generated by the process can be treated with standard biological methods. The EASW process can be used alone, or it can be used in combination with other soil-washing methods. In the latter case, the EASW process is particularly effective in the treatment of contaminated fines streams generated by other soil-washing techniques. The results of bench-scale batch tests with EASW used for washing petroleum hydrocarbons and pentachlorophenol contaminated soils will be discussed in this paper. Contaminant removal efficiencies of the EASW process, based on the difference between the contaminant concentrations in the feed soil and the washed soil, were above 99%. The performance of the EASW process in removing pentachlorophenol from soil was benchmarked against a commercially available process and found to be competitive.
Estimating structural attributes of Douglas-fir/western hemlock forest stands from Landsat and SPOT imagery

To help determine the utility of satellite data for analysis and inventory of Douglas-fir/western hemlock forests west of the Cascade Mountains crest in Oregon and Washington, USA, we evaluate relationships between spectral and texture variables derived from SPOT HRV 10 m panchromatic and LANDSAT TM 30 m multispectral data and 16 forest stand structural attributes. Texture of the HRV data was strongly related to many of the stand attributes evaluated, whereas TM texture was weakly related to all attributes. Wetness, a feature of the TM Tasseled Cap, was the spectral variable most highly correlated to all stand attributes. Wetness appears to respond to the degree of maturity in a forest stand. One of the primary reasons HRV texture and TM wetness exhibited strong relationships with stand attributes is their relative insensitivity to topographically induced illumination angle. Although TM texture also was insensitive to topography, the spatial resolution of TM data is too coarse to detect the spatial variability within the forest stands evaluated. Regression models used to estimate values for the stand attributes from the satellite data indicate that both TM and HRV imagery should yield equally accurate estimates of forest age class and stand structure. Of all stand attributes evaluated, the standard deviation of tree sizes, mean size and density of trees in the upper canopy layers, a structural complexity index, and stand age can be most reliably estimated using the satellite data.
Durability and strategic trade are there rents to be captured

Abstract This paper analyzes strategic trade policy when home and foreign duopolists produce a durable good that is either sold or leased in a third country. Durability is important for two reasons: it characterizes most of the products discussed in the strategic trade literature, and it also calls for explicit dynamic modeling. For duopolists who sell their product in a third-country market, this paper finds the optimal policy to be a tax on domestic output. For duopolists who lease the good in a third-country market, though, the optimal policy is a subsidy.
Gasification-induced densification of carbons: From soot to form coke

This article reviews the rapidly expanding literature on carbon densification during combustion or gasification and offers a new interpretation of data recently published in Combustion and Flame. A wide variety of carbonaceous solids, or carbons, play a role in combustion systems, including soots, cokes from liquid-fuel combustion, and chars from the high-temperature decomposition of organic solid precursors. The effect of partial gasification on the ultrafine structure of carbons, and the topic of carbon densification in general, is worthy of additional study, as it relates both to applications where densification and pore volume loss are detrimental (combustion of solid fuels, the manufacture of activated carbons and carbon foams) to those in which a high ultimate density or high mechanical strength is desired and often achieved at significant cost (manufacture of coke, synthetic graphite, and carbon--carbon composites).
Five years after central nervous system irradiation of children with leukemia.

Abstract Twenty-two children with acute lymphocytic leukemia (ALL) who attained complete remission and received preventive central nervous system (CNS) therapy consisting of 2400 rad cranial irradiation with five doom of intrathecal methotrexate followed by 28–36 months of multiple-agent chemotherapy were uniformly evaluated for potential toxicity upon neuropsychological functioning and somatic growth. Retrospective analysis of CNS signs, symptoms and function as well as head size, height and weight were tabulated at loon of therapy, the following 10 weeks, and at 28–36 months when all treatment was stopped. Sixty months after CNS therapy, a current assessment was performed attempting to identify any resultant neuropsychological aberration and disturbance in growth pattern. Nine of the 22 patients developed nonleukemic pleocytosis or presented headache, backache or leg pain. During the 10 weeks after CNS therapy, 8 of 22 patients developed transitory lethargy or somnolence. During continuation chemotherapy mild cerebro spinal fluid (CSF) pleocytosis was seen in some patents. Two children developed pseudo-tumor cerebri but recovered without sequelae. Neurological examination at 60 months was normal is all patients. Although initial head cicrumference averaged somewhat below normal, growth continued without significant deviation from the normal rate. Linear grow was slower than normal in 12 of the patients, following cessation of therapy only 2 persisted with a slower rhythm of longitudinal growth. Weight pattern was within one standard deviation at 5 years in all but 3 patients. About one-third of patients were rated below average in energy level, motivation, attention span, and concrete-abstract thinking, and one-third to one-ball rated above average in academic interest and approach to problems. We conclude from these results that prevention of CNS leukemia including 2400 rad of cranial irradiation in children with ALL Is effective and destitute of prohibitive toxicity on physical growth and neuropsychlogical competency.
NEW LIGHT ON ROBERT BOYLE AND THE DISCOVERY OF COLOUR INDICATORS

ROBERTBoyle's Experimental History of Colours (1664) is rightly considered a landmark in the history of analytical chemistry. In that work, Boyle described a number of simple but elegant experiments which ultimately gave chemists a powerful tool for determining the composition of compounds. He found, for example, that the common acids turned the blue syrup of violets red, and that alkalis turned it green. Subsequent experiments with other vegetable juices, including privet berries (Ligustrunt v.ulgare), buckthorn berries, (Rhamnus cathartica), cornflowers (Centauris cyanis), and turns ole (Crozophora tinctoria), revealed similar colour changes when treated with acids and alkalis.1 Although some of these reactions had been noticed earlier, Boyle was the first to recognize the significance of these substances as chemical reagents, for he alone observed that all acids turned such blue vegetable juices red, and that all alkalis turned them green. Furthermore, he noticed that some substances caused no colour change; these Boyle classified as neutral, neither acid nor alkaline, and thus "effectively disposed of the theory that all substances were one or the other".2 Recent scholarship has shown that an extensive literature on the analysis of aqueous solutions existed prior to Boyle's work, notably in the writings of physicians on the medicinal virtues of spa waters. Professor Allen Debus, for example, pointed out that Edward Jorden (1569-1632), an English physician trained at Padua, observed that bases turned scarlet cloth blue, while acids turned it red again; the colour change of tincture of violets and of rose leaves in the presence of oil of vitriol was also noticed in the early seventeenth century.3 Curiously, these writings are not mentioned by Boyle, and as Debus suggests, they do not seem to have made any noticeable contribution to Boyle's work on colour indicators.4 Another possible inspiration for Boyle's researches, however, has not thus far been seriously considered, and that was the empirical information accumulated by dyers and painters through generations of experimenting with colour changes. That Boyle should have observed these techniques in the workshops of dyers and colour-makers is entirely consistent with his professed adherence to Baconian philosophy. Indeed, if the scientific revolution of the seventeenth century was a matter in part of thinking in new ways about older data, Boyle's methodology in this instance is a remarkable example of it. It is not generally known that most of the colour changes that Boyle observed were noticed, and were induced methodically, long before anyone thought of using them as chemical indicators. Medieval dyers and painters knew empirically that plants could be made to yield a wide range of colours, depending on the season of the year in which they were collected and the mordants that were used with them. Unripe buckthorn berries, for example, yielded a fair but fugitive yellow that was used by painters to enrich greens, by leather dressers, and by bookbinders to colour the edges of books.5 If the berries were
Intracellular features of type II procollagen and chondroitin sulfate proteoglycan synthesis in chondrocytes

The intracellular compartments of chondrocytes involved in the synthesis and processing of type II procollagen and chondroitin sulfate proteoglycan (CSPG) monomer were investigated using simultaneous double immunofluorescence and lectin localization reactions. Type II procollagen was distributed in vesicles throughout the cytoplasm, whereas intracellular precursors of CSPG monomer were accumulated in the perinuclear cytoplasm. In this study, cytoplasmic vesicles that stained intensely with antibodies directed against CSPG monomer but did not react with type II collagen antibodies, also were observed. A monoclonal antibody, 5-D-4, that recognizes keratan sulfate determinants was used to identify the Golgi complex (the site of keratan sulfate chain elongation). Staining with 5-D-4 was restricted to the perinuclear cytoplasm. The vesicles outside the perinuclear cytoplasm that stained intensely with antibodies to CSPG monomer did not react with 5-D-4. Fluorescent lectins were used to characterize further subcellular compartments. Concanavalin A, which reacts with mannose-rich oligosaccharides, did not stain the perinuclear region, but it did stain vesicles throughout the rest of the cytoplasm. Because mannose oligosaccharides are added cotranslationally, the stained vesicles throughout the cytoplasm presumably correspond to the rough endoplasmic reticulum. Wheat germ agglutinin, which recognizes N-acetyl-D-glucosamine and sialic acid (carbohydrates added in the Golgi), stained exclusively the perinuclear cytoplasm. By several criteria (staining with the monoclonal antibody 5-D-4 and with wheat germ agglutinin), the perinuclear cytoplasm seems to correspond to the Golgi complex. The cytoplasmic vesicles that react with anti-CSPG monomer and not with anti-type II collagen contain precursors of CSPG monomer not yet modified by Golgi-mediated oligosaccharide additions (because they are not stained with wheat germ agglutinin or with the anti-keratan sulfate antibody); these vesicles may have a unique function in the processing of CSPG.
Contaminants in Stream Sediments From Seven United States Metropolitan Areas: Part I: Distribution in Relation to Urbanization

Organic contaminants and trace elements were measured in bed sediments collected from streams in seven metropolitan study areas across the United States to assess concentrations in relation to urbanization. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, the pyrethroid insecticide bifenthrin, and several trace elements were significantly related to urbanization across study areas. Most contaminants (except bifenthrin, chromium, nickel) were significantly related to the total organic carbon (TOC) content of the sediments. Regression models explained 45–80 % of the variability in individual contaminant concentrations using degree of urbanization, sediment-TOC, and study-area indicator variables (which represent the combined influence of unknown factors, such as chemical use or release, that are not captured by available explanatory variables). The significance of one or more study-area indicator variables in all models indicates marked differences in contaminant levels among some study areas, even after accounting for the nationally modeled effects of urbanization and sediment-TOC. Mean probable effect concentration quotients (PECQs) were significantly related to urbanization. Trace elements were the major contributors to mean PECQs at undeveloped sites, whereas organic contaminants, especially bifenthrin, were the major contributors at highly urban sites. Pyrethroids, where detected, accounted for the largest share of the mean PECQ. Part 2 of this series (Kemble et al. 2012) evaluates sediment toxicity to amphipods and midge in relation to sediment chemistry.
Dynamic compaction properties of bentonite

Abstract Bentonite has been proposed as a primary material for sealing shafts of nuclear waste repositories. It possesses low permeability, chemical and physical stability, and compatibility with most host rock masses and groundwater chemistries. This paper investigates the construction properties of bentonite and evaluates the use of dynamic compaction in constructing an effective bentonite shaft seal. Extensive laboratory tests of dynamic compaction have been conducted to study the densification of granular bentonite mixed with distilled deionized water or with brine from the Waste Isolation Pilot Plant (WIPP). Results of the dynamic compaction investigations delineate the influence of moisture content, compactive energy, mixed brine content, lift thickness, and rammer weight on the achievable dry density. Dynamic compaction can densify bentonite to a dry density of 1.86 Mg/m 3 when mixed with WIPP brine and 1.74 Mg/m 3 when mixed with distilled deionized water. At these densities bentonite exhibits permeabilities on the order of 1.0×10 −19 m 2 .
Simultaneous Multicomponent Registration of High-Resolution X-Ray Structures into Electron Microscopy Maps

A structural characterization of multicomponent cellular assemblies is essential to explain the mechanisms governing biological function. Macromolecular architectures may be revealed by integrating spatial information collected from various biophysical sources. For instance, low-resolution electron cryomicroscopy (cryo-EM) reconstructions of entire assemblies can be interpreted in relation with the crystal structures of the constituent fragments. A simultaneous registration of these multiple components is beneficial when building atomic models as it introduces additional spatial constraints to facilitate the native placement inside the map. The high-dimensional nature of such a search problem prevents the exhaustive exploration of all possible solutions. Here we introduce MOSAEC (Multi-Object Simultaneous Alignment by Evolutionary Computing), a method based on genetic algorithms, for the efficient exploration of the multi-body registration search space. MOSAEC employs principles inspired by biological evolution to iteratively optimize a population of candidate solutions. The classic scheme of a genetic algorithm was enhanced with new genetic operations, tabu search and parallel computing strategies and validated on a benchmark of synthetic and experimental cryo-EM datasets. Even at very low level of detail, MOSAEC successfully registered multiple component biomolecules, measuring accuracies within one order of magnitude of the nominal resolutions of the maps, for example 35-40 A.The present work was supported by NIH grant R01GM62968, a grant from the Gillson-Longenbaugh Foundation, and startup funds from the University of Texas at Houston.
The Spectrochemical Determination of Argon in Air

A spectrochemical procedure to determine the ratio of the concentration of argon in a sample slightly different from air to the concentration of argon in air was developed using an electrodeless discharge tube and a 22-foot direct-reading optical spectrometer. A precision of ±0.43% at the 95% confidence level was obtained for a single determination made in 1 minute. A method of relative precisions to obtain optimum adjustments of the equipment is described. This method was used to determine the optimum discharge tube pressure and the optimum entrance slit width.
Evaluating relationships between mercury concentrations in air and in Spanish moss (Tillandsia usneoides L.)

Abstract Measurement of mercury vapor is essential given that it is transported globally, and once deposited can be converted to methylmercury, a dangerous neurotoxin. A study was conducted in southeastern Georgia and northern Florida, USA to determine whether Spanish moss, an epiphytic vascular plant common to the southeastern United States, has the ability to retain mercury in its tissues over time, and to detect atmospheric mercury at relatively low concentrations from nonpoint sources. Spanish moss plants exposed to 10× and 100× ambient concentrations of mercury vapor increased tissue concentrations by 13.7 ± 11% and 74.1 ± 17% respectively, and then retained the mercury over two weeks following removal from the source. There was a strong trend of increasing Spanish moss mercury concentrations with increasing air concentration in resident populations across urban, rural inland, coastal and industrial sites. Transplanted Spanish moss around an industrial site contaminated with mercury exhibited a 164.8 ± 8.7% increase in mercury concentration after two weeks. Mercury concentration of Spanish moss transplanted to rural inland sites also increased after two weeks, while the change in transplant concentration at coastal sites was more variable. This study shows that Spanish moss possesses characteristics important for use as a bioindicator of atmospheric mercury, and can potentially be adapted as a tool for obtaining time-integrated atmospheric mercury data to add to existing atmospheric mercury monitoring programs.
Newer developments in in vitro monitoring of canine immune reactivity

Abstract These studies measured serial in vitro immunological parameters in canines receiving kidney transplants from DLA-incompatible donors. The results demonstrated reproducible patterns of changes in the in vitro parameters monitored. During rejection, there was no significant change in spontaneous lymphocyte blastogenesis (SB) although there was the suggestion of higher levels of SB during rejection. There was no significant change in the one-way mixed lymphocyte culture (MLC) during rejection. Rejection was associated with development of significant levels of direct T-cell cytotoxicity (LMC) and antibody-dependent cellular cytotoxicity (ADCC) to donor in all animals studied. In addition, studies of the infiltrating cells eluted from rejected kidneys showed significant levels of LMC and ADCC cytotoxicity. Studies of surface receptors of infiltrating cells indicated that most of these cells are T cells. Overall, these results indicate that canine allograft rejection is primarily executed by T cells which probably execute both LMC- and ADCC-type cytotoxicity.
Changes in retinal cell fate induced by overexpression of EGF receptor

The differentiation of multipotential progenitor cells in the vertebrate retina into photoreceptors, neurons and glial cells is regulated in part by cell-cell signalling. Transforming growth factor (TGF)-alpha is one of the extracellular signals implicated in the control of several aspects of retinal development, including proliferation and cell fate. The way cells interpret pleiotropic signals such as TGF-alpha is influenced by the level of expression of epidermal growth factor receptor (EGF-R) in some cell lines. To address the influence of receptor level on responses of retinal progenitor cells to TGF-alpha, additional copies of EGF-Rs were introduced in vitro and in vivo with a retrovirus. Normally in vitro, low concentrations of TGF-alpha stimulated proliferation whereas high concentrations biased choice of cell fate, inhibiting differentiation into rod photoreceptors while promoting differentiation into Muller glial cells. We report here that introduction of extra EGF-Rs into progenitor cells in vitro reduced the concentration of TGF-alpha required for changes in rod and Muller cell differentiation but did not enhance proliferation. Introduction of extra EGF-Rs in vivo increased the proportion of clones that contained Muller glial cells, suggesting that receptor level is normally limiting. These findings demonstrate that responsiveness to extracellular signals during development can be modulated by the introduction of additional receptors, and suggest that the level of expression of receptors for these signals contributes to the regulation of cell fate.
Conceptualizing institutional repositories: using co-discovery to uncover mental models

This study investigates how people construct mental models of new information systems with which they have limited experience. Six different institutional repositories were used as the experimental systems for this lab-based co-discovery experimental study. Sixty subjects (30 pairs) were asked to complete search tasks based on a simulated work situations using an institutional repository. Subsequently, subjects were instructed to visually depict how they thought the institutional repository worked and then explain this to their partner. Our findings are based on these drawings, descriptors written on drawings, and audio-recordings of explanations and conversations. The results reveal that most of the subjects constructed mental models focusing on system operations and the design of the user interface. Few highlighted the interactivity between the system and the end user or presented a global-view of the system to show how it related to other search engines or databases. We found that the co-discovery method provides a viable research design to elicit people's mental model construction. The implications of the results for interactive information retrieval community and institutional repository community are discussed in terms of research design, search behavior, and user instruction.
Predictors of Mammography Use in the Past Year among Elderly Women

Thirty-two personal characteristics were examined as potential predictors of mammography use in the past year in a geriatric clinic. Interviews assessed demographic, health status, health service utilization, health belief, and psychological and social variables (n = 242, mean age = 76 years). Four variables were independently associated with mammography use in logistic regression analysis: age, historical mammography use, perceived severity, and perceived barriers. The inverse relationship between age and mammography use in the past year was not modified by health status, functional status, and the other independently predictive variables. The authors conclude that geriatrics specialty care does not eliminate the age-associated decline in mammography use that has been previously described. The factors associated with mammography use in this sample were similar to those that have been described in younger populations of women. Variables examined because of specific gerontologic considerations were not ind...
QCD radiative corrections to helicity asymmetries in one-particle inclusive hadron processes

The ${{\ensuremath{\alpha}}_{S}}^{3}$ correction to the helicity cross section for the scattering of two quarks of unlike flavors, ${q}_{i}+{q}_{j}\ensuremath{\rightarrow}{q}_{k}+X$, is obtained. It gives a large correction to the helicity-dependent high-${p}_{T}$ hadronic process ${H}_{1}+{H}_{2}\ensuremath{\rightarrow}{H}_{3}+X$. Using previously obtained results for the ${{\ensuremath{\alpha}}_{S}}^{3}$ correction to the helicity-averaged case, the correction to the initial-initial helicity asymmetry in this process is found to be small. This offers support for the lowest-order analysis of this asymmetry.
Loss of hue discrimination in forebrain-ablated fish

Abstract The effect of forebrain ablation on hue discrimination in fish has been studied. Cardiac deceleration, a conditioned autonomic response, was used as the measure of discrimination in a series of goldfish. Electric shock was the unconditioned stimulus. Forebrain-ablated fish were trained to a red and a green stimulus selected to be of equal brightness. These fish were subsequently tested on red and green stimuli of known brightness, as perceived by these experimental animals. Normal fish in this situation reacted to the test stimuli on the basis of their wavelength characteristics, but forebrainless animals reacted only to the brightness and not to the wavelength characteristics of the test stimuli. Other control tests substantiate this finding.
The role of the weakest-link mechanism in controlling the plasticity of micropillars

Abstract We present a computational study on the effects of sample size on the strength and plastic flow characteristics of micropillars under compression loading. We conduct three-dimensional simulations using the parametric dislocation dynamics coupled with the boundary element method. Two different loading techniques are performed. The plastic flow characteristics as well as the stress–strain behavior of simulated micropillars are shown to be in general agreement with experimental observations. The flow strength versus the diameter of the micropillar follows a power law with an exponent equal to - 0.69 . A stronger correlation is observed between the flow strength and the average length of activated dislocation sources. This relationship is again a power law, with an exponent - 0.85 . Simulation results with and without the activation of cross-slip are compared. Discontinuous hardening is observed when cross-slip is included. Experimentally observed size effects on plastic flow and work-hardening are consistent with a “weakest-link activation mechanism”.
A Novel Instrument for the Quantification of Hand Forces During Jar Opening

change in biceps and anterior deltoid muscle activity when the test was performed in a supinated position versus a pronated position. Methods: Ten healthy subjects with no history of shoulder or scapular dysfunction were recruited from a population of convenience. To determine the maximal volitional contraction (MVC), surface electrodes were applied to the long head of the biceps and the anterior deltoid and muscle activity recorded during traditional manual muscle tests. Each subject then performed the Speed’s test with the arm pronated and again with the arm supinated. Three, 5second trials were taken in each test position. Resistance was standardized to 6.4 kg 6 0.5 kg as measured by a hand held dynamometer. All tests were performed in random order on the dominant and the nondominant arm resulting in values for twenty shoulders. Results: Forearm position did not significantly affect the anterior deltoid activity but did significantly alter the activity of the long head of the biceps (p 5 0.006). Mean biceps activity was approximately 60% greater when the forearm was supinated (mean percent of MVC 5 0.898) versus pronated (mean percent of MVC 5 0.532). Some evidence was found that dominance influenced biceps activity but not deltoid activity. Conclusion: This study supports the explanation that a positive Speed’s test could be associated with increased activity in the long head of the biceps. Because a normal population was used, further testing should be done with individuals who have shoulder impairments. Additional study into the role of dominance will also contribute to the understanding of the Speed’s test.
Effect of a Rising R‐Curve on the Sliding Wear of Silicon‐Disilicide In Situ Composites

This study investigates the tribological behavior of a new class of silicon-disilicide (Si-(Cr,V)Si2) in situ composites which display eutectic microstructures comprising a Si matrix and reinforcing (Cr,V)Si2 disilicide phase. Dry, room temperature ball-on-disk tests carried out at various loads (W = 1–6 N) showed that the specific wear rates of the Si-(Cr,V)Si2 composites (ka ≈10−5 mm3/Nm) were about an order of magnitude lower than that of unalloyed Si (ka ≈10−4 mm3/Nm) in the wear regime dominated by lateral cracking. Microscopic analysis of the wear tracks, as well as observations from indentation experiments, revealed that the improved wear resistance of the Si-(Cr,V)Si2 composites at higher loads was due to the activation of crack deflection and bridging toughening mechanisms during the wear process, which results in a rise in the apparent composite fracture toughness with increasing crack size (i.e., a rising R-curve behavior). Analysis of the wear test data in the context of a lateral fracture wear model demonstrates that the enhanced short-crack response of the Si-(Cr,V)Si2 composites during sliding wear can indeed be explained by the incorporation of a sharply rising R-curve relation for the composite fracture toughness.
Long-term outcome of bilateral lung volume reduction in 250 consecutive patients with emphysema

Abstract Objective: Numerous reports have confirmed the early benefits of lung volume reduction surgery for selected patients with emphysema. This report documents the long-term survival and functional results after lung volume reduction surgery. Methods: Between January 1993 and June 2000, a total of 250 consecutive patients underwent bilateral lung volume reduction surgery through median sternotomy at our institution. All patients had disabling dyspnea, thoracic hyperinflation, and a heterogeneous pattern of emphysema with suitable target areas for resection. Preoperative pulmonary rehabilitation was required and post-rehabilitation data were used as the baseline for data analysis. Follow-up ranged from 1.8 to 9.1 years (median 4.4 years). Results: Prolonged air leaks (>7 days) were the most common complication (45.2%, n=113). Reexploration rates for air leak and bleeding were 3.2% (n = 8) and 1.2% (n = 3), respectively. Eighteen patients (7.2%) required reintubation and mechanical ventilation. The in-hospital mortality in this series was 4.8% (n = 12). The median length of hospitalization was 9 days (range 4-168 days). Kaplan-Meier survivals after lung volume reduction surgery were 93.6%, 84.4%, and 67.7% at 1, 3, and 5 years, respectively. Eighteen patients (7.2%) have subsequently undergone lung transplantation after a median interval of 4.3 years (range 2.1-6.4 years). Spirometric values, lung volumes, and gas exchange parameters improved after surgery. The forced expiratory volume in 1 second and the residual volume showed statistically significant improvements between preoperative values and each time point of follow-up. Health-related quality of life showed significant postoperative improvement and with time correlated well with the improvement in forced expiratory volume in 1 second. Conclusions: Lung volume reduction surgery produces significant functional improvement for selected patients with emphysema. For most of these patients, benefits appear to last at least 5 years. J Thorac Cardiovasc Surg 2003;125:513-25
A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region, Arizona, USA

Urbanization is arguably the most dramatic form of land transformation that profoundly influences biological diversity and human life. Quantifying landscape pattern and its change is essential for the monitoring and assessment of ecological consequences of urbanization. Combining gradient analysis with landscape metrics, we attempted to quantify the spatial pattern of urbanization in the Phoenix metropolitan area, Arizona, USA. Several landscape metrics were computed along a 165 km long and 15 km wide transect with a moving window. The research was designed to address four research questions: How do different land use types change with distance away from the urban center? Do different land use types have their own unique spatial signatures? Can urbanization gradients be detected using landscape pattern analysis? How do the urban gradients differ among landscape metrics? The answers to these questions were generally affirmative and informative. The results showed that the spatial pattern of urbanization could be reliably quantified using landscape metrics with a gradient analysis approach, and the location of the urbanization center could be identified precisely and consistently with multiple indices. Different land use types exhibited distinctive, but not necessarily unique, spatial signatures that were dependent on specific landscape metrics. The changes in landscape pattern along the transect have important ecological implications, and quantifying the urbanization gradient, as illustrated in this paper, is an important first step to linking pattern with processes in urban ecological studies.
The Utah TENEX scheduler

A scheduling algorithm which is a modification of the standard TENEX scheduler is described. This algorithm differs from those commonly used in time-sharing systems in that it treats the case of multiple critical resources. The Utah scheduler considers CPU usage and real core occupancy, but the same techniques can be applied to cases of more than two critical resources. Similar scheduling tehniques can be applied to interactive batch-processing systems and to resource sharing systems.
Efficient evaluation of multivariate polynomials over multidimensional grids

Let P(x 1 , x 2 , ... , x n ) be a multivariate polynomial in n variables, x 1 , x 2 , ... , x n and suppose that P(x 1 , x 2 , ... , x n ) is of degree m i in x i , i = 1, 2, ... , n. It is shown how P(x 1 , x 2 , ... , x n ) may be evaluated at x i = x 0i + n i Δ i for n i = 0, 1, 2, ... and i = 1, 2, ... , n using not more than (m 1 + m 2 + ... + m n ) additions per point. Feasibility of reduction from this upper bound is demonstrated in the n = 2 case.
Non‐Racialism Versus Nationalism: ContrastingSolutions to Conflict in South Africa and Israel/Palestine

South Africa and Israel/Palestine present dramatically different courses of social change. Both have roots as settler societies, albeit with some distinct differences. The quest to bridge the ethnic nationalism separating the settlers from the indigenous peoples has led in South Africa to an inclusivist nationalism and a redefinition of the state. In contrast, Israeli Jews and Palestinian Arabs each cling to essentially nationalist definitions of the state, closely linked to ethnicity and sometimes religion. Does SouthAfrica offer lessons for Israel/Palestine? Will the latter conflict be resolved with-out seriously reconsidering the concept of a “Jewish state”? The sources and strength of nationalism suggest that peace between Palestinian Arabs and Israeli Jews still may be many years away .
A comparative review of statistical methods for discovering differentially expressed genes in replicated microarray experiments.

Motivation A common task in analyzing microarray data is to determine which genes are differentially expressed across two kinds of tissue samples or samples obtained under two experimental conditions. Recently several statistical methods have been proposed to accomplish this goal when there are replicated samples under each condition. However, it may not be clear how these methods compare with each other. Our main goal here is to compare three methods, the t-test, a regression modeling approach (Thomas et al., Genome Res., 11, 1227-1236, 2001) and a mixture model approach (Pan et al., http://www.biostat.umn.edu/cgi-bin/rrs?print+2001,2001a,b) with particular attention to their different modeling assumptions. Results It is pointed out that all the three methods are based on using the two-sample t-statistic or its minor variation, but they differ in how to associate a statistical significance level to the corresponding statistic, leading to possibly large difference in the resulting significance levels and the numbers of genes detected. In particular, we give an explicit formula for the test statistic used in the regression approach. Using the leukemia data of Golub et al. (Science, 285, 531-537, 1999), we illustrate these points. We also briefly compare the results with those of several other methods, including the empirical Bayesian method of Efron et al. (J. Am. Stat. Assoc., to appear, 2001) and the Significance Analysis of Microarray (SAM) method of Tusher et al. (PROC: Natl Acad. Sci. USA, 98, 5116-5121, 2001).
Investment Preferences and the Desire for Security: A Comparison of Men and Women

Summary A questionnaire designed to measure the degree of emphasis placed upon a desire for security in investment preferences was completed anonymously by 90 men and 91 women. The difference between the mean security rating of the men when compared to that of the women was not statistically significant. However, a mean security rating for 64 men and women with the occupational orientation of teaching or civil service was higher than that for the 117 other participants in the study, the difference being statistically significant at the .05 level. The results suggest that variables other than sex are more significantly related to a desire for security in decisions concerning investment preferences, and these results roughly parallel the findings of a previous study in the area of vocational choice.
Syntheses and structural characterizations ofcloso and nido 10-vertex metallatricarbanonaboranes

Deboronation of the 11-vertex metallatricarbadecaboranes 1-(η 5 -C5H 5 )-2-Ph- closo -1,2,3,4-M-C 3 B 7 H 9 [M = Ru, Fe] and 1,1,1-(CO) 3 -2-Ph- closo -1,2,3,4-M-C 3 B 7 H 9 [M = Re] with tetrabutylammonium fluoride (TBAF) produced the first examples of the 10-vertex families of closo and nido metallatricarbanonaborane complexes, 2-(η 5 -C5H 5 )-10-Ph- closo -2,1,6,10-M-C 3 B 6 H 8 [M = Ru ( 1 ), Fe ( 2 )] and 5,5,5-(CO) 3 -10-Ph- nido -5,6,9,10-Re-C 3 B 6 H 9 – ( 3 ). Crystallographic characterizations of 1 and 3 confirmed geometries, based on a bicapped square antiprism for 1 and a bicapped square antiprism with one missing vertex for 3 , that are consistent with their respective 22 ( closo ) and 24 ( nido ) skeletal-electron counts.
Free‐Standing Arrays of Isolated TiO2 Nanotubes through Supercritical Fluid Drying

A common complication in fabricating arrays of TiO(2) nanotubes is that they agglomerate into tightly packed bundles during the inevitable solvent evaporation step. This problem is particularly acute for template-fabricated TiO(2) nanotubes, as the geometric tunability of this technique enables relatively large inter-pore spacings or, from another perspective, more space for lateral displacement. Our work showed that agglomeration results from the surface tension forces that are present as the ambient solvent is evaporated from the nanotube film. Herein, we report a processing and fabrication approach that utilizes supercritical fluid drying (CO(2)) to prepare arrays of template-fabricated TiO(2) nanotubes that are free-standing and spatially isolated. This approach could be beneficial to many emerging technologies, such as solid-state dye-sensitized solar cells and vertically-oriented carbon nanotube electrodes.
Effects of visual deprivation and alterations in binocular competition on responses of striate cortex neurons in the cat

Electrophysiological recordings were made from single neurons in striate cortex of normally reared kittens (group N), kittens raised with binocular lid-suture (group BD), and kittens raised with one eye lid-sutured and the other eye removed (group MD-E). The MD-E group represents a condition in which inputs from the deprived eye have been placed at a competitive advantage over those from the other eye. In agreement with previous studies, fewer cells were responsive to visual stimulation in BD kittens than in N kittens. Among the responsive cells, fewer were direction selective, fewer were orientation selective, and more had inconsistent or fast-adapting responses than in normals. The responsiveness and receptive field properties of striate cortex neurons in the MD-E kittens were less affected by the visual deprivation than in BD kittens; however, they still were abnormal in comparison to normal kittens. Comparison of the ocular dominance distributions for cells in N and BD kittens showed a marked reduction in binocularly driven cells in BD kittens. In addition, in BD kittens, a larger proportion of monocularly driven cells had orientation selective receptive fields than did binocularly driven cells. This difference was not found in normally reared kittens. The results of this study suggest that abnormal binocular interactions contribute to the effects of visual deprivation following binocular lid-suture, probably due to asynchronous light-dark inputs through the closed lids. Removing the other eye and placing inputs from the deprived eye at a competitive advantage during development results in decreased effects on striate cortex neurons. Nevertheless, visual deprivation still produces abnormalities in striate cortex independent of asynchronous or uncorrelated visual stimulation of the two eyes.
Vibrio cholerae OmpU and OmpT Porins Are Differentially Affected by Bile

OmpT and OmpU are pore-forming proteins of the outer membrane of Vibrio cholerae, a pathogen that colonizes the intestine and produces cholera. Expression of the ompU and ompT genes is under the regulation of ToxR, a transmembrane transcriptional activator that also controls expression of virulence factors. It was recently shown that bile stimulates the ToxR-mediated transcription of ompU and that ompU-expressing strains are more resistant to bile and anionic detergents than ompT-expressing cells. In order to further understand the role of the OmpT and OmpU porins in the ability of V. cholerae to survive and colonize the host intestine, we examined the outer membrane permeability of cells expressing only ompU or only ompT or both genes in the absence and in the presence of bile. By comparing various strains in terms of the rate of degradation of the β-lactam antibiotic cephaloridine by the periplasmic β-lactamase, we found that the permeation of the antibiotic through the outer membrane of OmpU-containing cells was slower than the permeation in OmpT-containing cells. In addition, the OmpU-mediated outer membrane permeability was not affected by external bile, while the OmpT-mediated antibiotic flux was reduced by bile in a concentration-dependent manner. Our results confirm that OmpT and OmpU provide a passageway for hydrophilic solutes through the outer membrane and demonstrate that bile might interfere with this traffic in OmpT-producing cells by functionally inhibiting the OmpT pore. The insensitivity of OmpU to bile may be due to its small pore size and may provide an explanation for the resistance of OmpU-producing cells to bile in vivo.
One-step self-assembly organometallic molecular cages from 11 components

Two self-assembly organometallic molecular cages, each comprising 11 components and two different bridging ligands, were prepared from one-step reactions; both of these cages exhibit relatively high affinity and shape-selectivity toward planar aromatic compounds.
RNAi-based therapeutics–current status, challenges and prospects

RNA interference (RNAi) is a collection of small RNA directed mechanisms that result in sequence specific inhibition of gene expression. The notion that RNAi could lead to a new class of therapeutics caught the attention of many investigators soon after its discovery. The field of applied RNAi therapeutics has moved very quickly from lab to bedside. The RNAi approach has been widely used for drug development and several phase I and II clinical trials are under way. However, there are still some concerns and challenges to overcome for therapeutic applications. These include the potential for off-target effects, triggering innate immune responses and most importantly obtaining specific delivery into the cytoplasm of target cells. This review focuses on the current status of RNAi-based therapeutics, the challenges it faces and how to overcome them.
Parental Alarm Calls of the White-Crowned Sparrow Fail to Stimulate Corticosterone Production in Nest-Bound Offspring

Alarm calling by parents is widespread among animals and has strong implications for parent and offspring fitness, yet it is virtually unknown whether parental alarm calls can initiate a corticosterone response in offspring. We investigated whether parental alarm calls of the whitecrowned sparrow, Zonotrichia leucophrys, activated the corticosterone response of their nest-bound young, as such a response might prepare older nestlings for premature fledging and increase their survival when contacted by a predator at the nest. We conducted an experiment in which nestlings were either exposed to parent alarm calls (treatment) or experienced a period without parental alarm calls (control) immediately prior to blood sampling. We then sampled nestlings to measure corticosterone levels within 4 min of first contact (baseline corticosterone) and 60 min later (handling-induced corticosterone). Young nestlings (i.e. 3– 4 d post-hatch) did not exhibit a corticosterone response to parental alarm calls or to handling, as mean corticosterone levels were similar in the control and treatment groups for both baseline and 60-min postbaseline samples. Against our predictions, there was no difference in mean levels of baseline corticosterone between control and treatment groups in older nestlings (i.e. 7)8 d post-hatch) that were capable of surviving out of the nest. However, we did find a significant increase in mean levels of corticosterone after handling in both groups, which indicated that older nestlings were able to mount a functional corticosterone response when confronted with a potential predator. Why older nestlings did not initiate a corticosterone response after exposure to parental alarm calls is unclear but may have occurred because the costs of mounting such a response outweighed the benefits, perhaps because of growth or developmental costs.