cssi/SciSciGPT-SciSciNet huggingface dataset:
A 14-year experience with blunt thoracic aortic injury.

Objective This study reviewed the natural history of blunt thoracic aortic trauma (BTAT) over a 14-year period at our level 1 trauma center and compared open vs endovascular treatment. Methods All patients with BTAT presenting to a level 1 trauma center from 1998 to 2011 were included in a retrospective analysis. Multiple data points and short-term and midterm outcomes were ascertained through a retrospective record review. Results We identified 129 patients with BTAT. Of these, 32 (25%) were dead on arrival, 38 (29%) underwent a resuscitative thoracotomy and died, 33 (26%) underwent open repair, 14 (11%) underwent endovascular repair, 9 (7%) underwent simultaneous procedures, and 3 (2%) were managed nonoperatively. Mean Injury Severity Scores and Revised Trauma Scores were similar ( P = .484, P = .551) between the open repair group (n = 36) and the endovascular repair group (n = 14). In the open repair group, there were 14 deaths (42%) ≤30 days of injury, 3 strokes (9%), 2 patients (6%) with paralysis, 2 myocardial infarctions (MIs; 6%), and 3 patients (9%) who required hemodialysis. In the endovascular group, there was 1 death (7%) ≤30 days of injury, 1 (7%) stroke, and 1 (7%) stent collapse. No paralysis, MI, or renal failure requiring hemodialysis was noted in the endovascular group. The average length of stay was 15 days for patients treated with endovascular repair vs 24 days for those treated with open repair ( P = .003). Conclusions The incidence of BTAT is low but the mortality associated with it is significant. During the 14-year period studied, there was a clear change in management preference from open repair to endovascular repair at our level 1 trauma center. Outcomes, including stroke, MI, renal failure, paralysis, length of stay, and death, appear to be reduced in the endovascular group.
Progrès économique et social dans les réseaux de production mondiaux: problèmes de théorie et de mesure

Resume. Le developpement economique devient synonyme de «progres economique» au sein des reseaux de production mondiaux (RPM). Toutefois, si ce progres, associea la croissance economique et a la performance du commerce international, a fait l'objet de nombreuses recherches, il y a eu moins d'analyses sur ce qu'il signifie pour le «progres social»: salaires, conditions de travail, droits, egalite des sexes et securiteeconomique des travailleurs dans les RPM. Les auteurs examinent la facon dont on mesure le progres economique et social, notamment dans les pays en developpement, et analysent la relation theorique entre ces deux dimensions du progres. Ils concluent par une breve discussion sur les implications politiques.
Learning-Based Vessel Segmentation in Mammographic Images

In this paper we propose using a learning-based method for vessel segmentation in mammographic images. To capture the large variation in vessel patterns not only across subjects, but also within a subject, we create a feature pool containing local, Gabor and Haar features extracted from mammographic images generating a feature space of very high dimension. We also employ a huge number of training samples, which essentially contains the pixels in the training images. To deal with the very high dimensional feature space and the huge number of training samples, we apply a forest with boosting trees for vessel segmentation. Specifically, we use the standard AdaBoost algorithm for each tree in the forest. The randomness is encoded, when training each AdaBoost tree, using randomly sampled training set (pixels) and randomly selected features from the whole feature pool. The proposed method is tested using a real dataset with 20 anonymous mammographic images. The effectiveness of the proposed features and classifiers is demonstrated in the experiments where we compare different approaches and feature combinations. In the paper, we also present full analysis of different types of features.
Recursive fast algorithm and the role of the tensor product

The use of the tensor product for modeling and designing FFT algorithms is addressed. The benefit of the tensor product approach lies in the strong connection between certain tensor product constructs and important computer architectures. The scope of the tensor product approach is generalized to include a much larger class of fast recursive algorithms. This greatly enhances the versatility of the tensor product technique and brings many different algorithms to the level of understanding and flexibility enjoyed by the FFT. >
Are being unemployed and being out of the labor force distinct states?: A psychological approach

Abstract Clark and Summers (1979) found a high rate of transition between unemployed and out of the labor force status. These findings led them to conclude that “many of those classified as not in the labor force are functionally indistinguishable from the unemployed.” Flinn and Heckman (1982,1983) questioned the validity of the conclusion reached by Clark and Summers. Heretofore, the debate between Clark and Summers and Flinn and Heckman over whether the two forms of nonemployment are distinct states has been conducted by examining transition probabilities and observable external characteristics. Unfortunately, the narrowness of the debate may have prevented this issue from being resolved. Psychologists have offered several explanations that seek to establish how experiences such as joblessness can lead to a deterioration in psychological health. For instance, unemployment may damage a person's locus of control, a concept that accounts for perceptions of personal efficacy, leaving them with a sense of helplessness. Although the psychological status of individuals in the two states of joblessness may differ, due to their respective rationales for withdrawal from the labor force, this possibility has yet to be investigated. This paper uses data from the National Longitudinal Survey of Youth (NLSY) to examine whether a difference in psychological well-being exists between the unemployed and labor force drop outs. We find some evidence that joblessness fosters feelings of externality. In addition, we also find evidence in favor of the stages of psychological impairment theory. Moreover, as the duration of joblessness advances so do feelings of helplessness. Finally, on balance, we offer evidence on the psychological status of the jobless that is consistent with the view of Clark and Summers that the two forms of joblessness are effectively indistinguishable.
Number of first-contact access components required to improve preventive service receipt in primary care homes.

BACKGROUND A fundamental aim of primary care redesign and the patient-centered medical home is improving access to care. Patients who report having a usual site of care and usual provider are more likely to receive preventive services, but less is known about the influence of specific components of first-contact access (e.g., availability of appointments, advice by telephone) on preventive services receipt.
J = 0,T = 1 pairing-interaction selection rules

Wave functions arising from a pairing Hamiltonian E(0) i,e, one in which the interaction is only between J=0 + T=1 pairs, lead to Gamow-Teller transition rates that are much larger than those from an interaction E(Jmax) in which a proton and a neutron couple to J=2j. With realistic interactions the results are in between the 2 extremes. In the course of this study we found that certain GT matrix elements vanish with E(0) e.g. J=(7/2 )1 to J=5/2 or 9/2 in decays of 43 Sc and 45 Sc to 43 Ca and 45 Ca. We find the surprising result that The M1 strength to the “single j scissors” is larger for a J=0 T=1 pairing interaction than it is for Q.Q.
Modification of homogeneous resistance in a methicillin-resistant strain of Staphylococcus aureus by acquisition of a β-lactamase encoding plasmid

Nearly all clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) are heterogeneously resistant and produce beta-lactamases which generally are plasmid mediated. In order to study the role of beta-lactamase plasmids in the expression of methicillin resistance, a beta-lactamase plasmid from Enterococcus faecalis HH22 (pBEM10) was transferred into a homogeneously resistant, beta-lactamase-negative strain of MRSA (MUSC284). By single disc diffusion testing at 42 degrees C, beta-lactamase producing transconjugants (SA-MM1) were found to be more susceptible than the parent strain to methicillin, imipenem, SCH 34343 and cloxacillin, but more resistant to piperacillin. The heterogeneity observed in transconjugants was not affected by the addition of clavulanic acid, indicating that beta-lactamase itself was not responsible for this effect. By population analysis over 50% of MUSC284 colonies and less than 1% of SA-MM1 colonies remained viable after incubation at 42 degrees C in agar plates containing 25 mg/l of cloxacillin. Cured derivatives of SA-MM1 reverted to homogeneous resistance to beta-lactam antibiotics as observed in the initial parenteral strain MUSC284. Thus, the introduction of a beta-lactamase coding plasmid into a homogeneously resistant MRSA yielded transconjugants which resembled heterogeneously resistant strains of MRSA. These results suggest that regulatory genes, capable of altering the expression of methicillin resistance, may be located on beta-lactamase plasmids commonly found in these organisms.
The effect of wavelet-based dimension reduction on neural network classification and subpixel targeting algorithms

The effect of using Adaptive Wavelets is investigated for dimension reduction and noise filtering of hyperspectral imagery that is to be subsequently exploited for classification or subpixel analysis. The method is investigated as a possible alternative to the Minimum Noise Fraction (MNF) transform as a preprocessing tool. Unlike the MNF method, the wavelet-transformed method does not require an estimate of the noise covariance matrix that can often be difficult to obtain for complex scenes (such as urban scenes). Another desirable characteristic of the proposed wavelet transformed data is that, unlike Principal Component Analysis (PCA) transformed data, it maintains the same spectral shapes as the original data (the spectra are simply smoothed). In the experiment, an adaptive wavelet image cube is generated using four orthogonal conditions and three vanishing moment conditions. The classification performance of a Derivative Distance Squared (DDS) classifier and a Multilayer Feedforward Network (MLFN) neural network classifier applied to the wavelet cubes is then observed. The performance of the Constrained Energy Minimization (CEM) matched-filter algorithm applied to this data us also observed. HYDICE 210-band imagery containing a moderate amount of noise is used for the analysis so that the noise-filtering properties of the transform can be emphasized. Trials are conducted on a challenging scene with significant locally varying statistics that contains a diverse range of terrain features. The proposed wavelet approach can be automated to require no input from the user.
Inhibition of L-dopa-induced growth hormone stimulation by pyridoxine and chlorpromazine.

One gram of l-dopa was administered orally to 12 male control subjects and induced an increase of growth hormone (GH) secretion. The l-dopa-induced GH response was inhibited by an intravenous infusion of pyridoxine, but pyridoxinedid not inhibit the GH response to hypoglycemia. Chlorpromazine also inhibited l-dopa-induced GH stimulation. Glucose concentrations were unaffected by l-dopa, chlorpromazine, and pyridoxine administration in these subjects. The mechanism of the suppressed l-dopa-induced GH response by pyridoxine appears to be mediated by peripheral acceleration of the conversion of l-dopa to dopamine, while that of chlorpromazine appears to be mediated through hypothalamic centers. Pyridoxine and chlorpromazine should be added to the list of other factors affecting the response to L-dopa-induced GH stimulation.
Conformational changes and molecular dynamics of simple silica immobilized systems

A brief review of the author's and co-workers' investigations as they relate to understanding the conformation and dynamics of chemically-modified liquid chromatographic surfaces is presented. Previously reported non-linear chromatographic behavior when using near to totally aqueous mobile phases as eluents are discussed as well as selected infrared, electron spin resonance and nuclear magnetic resonance experiments. Emphasis is placed on more recent applications of 2H wide-line NMR spectroscopy and band shape analysis in infrared spectroscopy in order to study conformation and dynamics of the bonded ligands in different time regimes.
Ovarian Hormones and Drug Abuse

There are significant gender differences in course, symptomology, and treatment of substance use disorders. In general data from clinical and preclinical studies of substance use disorders suggest that women are more vulnerable than men to the deleterious consequences of drug use at every phase of the addiction process. In addition data from epidemiologic studies suggest that the gender gap in the prevalence of substance use is narrowing particularly among adolescence. Therefore, understanding the role of estrogen and progesterone in mediating responses to drugs of abuse is of critical importance to women's health. In this review we will discuss findings from clinical and preclinical studies of (1) reproductive cycle phase; (2) endogenous ovarian hormones; and (3) hormone replacement on responses to stimulants, nicotine, alcohol, opioids, and marijuana. In addition, we discuss data from recent studies that have advanced our understanding of the neurobiologic mechanisms that interact with estrogen and progesterone to mediate drug-seeking behavior.
The Public Health Burden of Diabetes and the Reality of Limits

Improvements in diabetes surveillance, diagnosis, and treatment have, in recent years, heightened awareness of the burden of diabetes and aroused concern about the amount of health care resources that will be necessary to manage this disease effectively in the future. Examination of diabetes from the twin perspectives of economics and public health challenges basic notions of the health care tradition in the Western world: the real-world combination of finite resources and the growing need/demand for health services forces the consideration of limits in the provision of health care. The growing need to rationally allocate limited health care resources poses emotional, potentially divisive questions of science, politics, economics, and ethics that patients and physicians must each address.
How does the robot affect outcomes? A retrospective review of open, laparoscopic, and robotic Heller myotomy for achalasia.

Background Robotic techniques are routinely used in urological and gynecological procedures; however, their role in general surgical procedures is limited. A robotic technique has been successfully adopted for a minimally invasive Heller myotomy procedure for achalasia. This study aims to compare perioperative outcomes following open, laparoscopic, and robotic Heller myotomy.
Clinical and radiographic outcome in the management of posterior circulation aneurysms by use of direct surgical or endovascular techniques.

OBJECTIVE: Posterior circulation aneurysms can be difficult lesions to treat surgically and they have potentioal for high morbidity and mortality, particularly in elderly patients or those in poor neuroligical condition. In an effort to improve outcomes, our combined neurosurgical and neuroendovascular unit has used both surgical clipping and endovascular coiling techniques to treat posterior circulation aneurysms. Patients considered at high risk for surgery were managed with endovascular treatment. METHODS: From 1990 to 1998, 197 posterior circulation aneurysms in 189 patients were treated in our combined neurovascular unit. Of these aneurysms, 128 were ruptured, 63 were unruptured, and 6 had a distant history of rupture in patients who came to our center for delayed or repeat treatment. A total of 132 aneurysms were treated with surgical clipping (85 ruptured, 46 unruptured, and 1 with distant history of rupture) and 65 aneurysms were treated with endovascular coiling (43 ruptured, 17 unruptured, and 5 with distant history of rupture). Dissecting aneurysms of the vetebral or posteroinferior cerebellar arteries or aneurysms treated with proximal (Hunterian) occlusion were excluded from this analysis. Surgical risk was assessed using a previously described system (Massachusetts General Hospital [MGH] grade), which incorporates age, Hunt and Hess grade, size of lesion, and Fisher grade. RESULTS: Overall clinical outcomes as 1 year of follow-up were 77.2% excellent or good, 10.2% fair, 4.1% poor, and 8.6% dead. Surgical treatment resulted in 95.6% complete aneurysm occlusion and 4.4% with residual aneurysm after surgical treatment, whereas endovascular occlusion and 4.4% with residual aneurysm after surgical treatment, whereas endovascular treatment resulted in 32.3% complete occlusion, 26.2% with residual aneurysm, and 41.5% with partial occlusion. In most cases, however, treatment with Guglielmi detachable coils (Boston Scientific/ Target, Fremont, CA) was performed for pallialtion rather than complete radiographic occlusion. Outcome was closely associated with MGH grade with either treatment modality. Excellent/good outcomes were achieved in 96.3, 82.9, 46.2 and 0% of surgically treated patients with MGH Grades of 0, 1, 2, 3, and 4, respectively. In comparison, excellent/good outcomes were achieved in 100, 84.2, 61.9, 0, and 50% of endovascularly treated patients which MGH Grades of 0, 1, 2, 3, and 4, respectively. CONCLUSION: A combined surgical and endovascular approach to posterior circulation aneurysms can achieve good outcomes in high-risk surgical patients treated by use of coiling techniques.
Pore water fluoride in Peru continental margin sediments: Uptake from seawater

Abstract Fluoride analyses display downward decreasing pore water gradients in Peru shelf phosphatic muds that require diffusion from the overlying seawater into the sediment column and removal by reaction within the upper few tens of centimeters, presumably by incorporation into carbonate fluorapatite. The profiles can be modeled as first-order F-removal with rate constants of ~3 yr −1 and asymptotic F-concentrations deep in the cores of 35–45 μM, almost one-half the seawater value. The integrated flux of fluoride from seawater into organic-rich shelf sediments in coastal-upwelling zones (phosphatic muds) yields a contemporaneous global F-burial of 0.54 × 10 10 mol-F yr −1 , about one-fifth the burial in other sinks (mostly carbonates and opal). The associated burial flux of phosphorus in shelf phosphorites is about 1.6 × 10 10 mol-P yr −1 , comparable to P-burial in the deep sea with organic matter (~1.4 × 10 10 mol yr −1 ) and biogenic carbonates (~1.4 × 10 10 mol yr −1 ). Thus phosphorite formation on the Peru shelf is a significant contemporaneous process.
Ultra-sensitive, room-temperature THz detection based on parametric upconversion by using a pulsed 1550nm optical source

We demonstrate ultra-sensitive optical detection of terahertz by using nonlinear parametric upconversion. Terahertz radiation is mixed with pump light at 1550 nm in a nonlinear crystal to generate an optical sideband or idler wave. The idler signal is separated from the optical pump, coupled into an optical fiber and detected using a Geiger-mode avalanche photo-diode. Our scheme to detect THz waves leverages mature technology at 1550 nm developed for telecommunications to enable ultra-sensitive detection at room-temperature. We have fabricated a diffusion-bonded, quasi phasematched GaAs crystal, a χ (2) nonlinear material, that is pumped with a readily obtainable erbium doped fiber amplifier to perform the parametric conversion. We demonstrate efficient upconversion of terahertz radiation using both a continuous-wave THz source operating at 0.82 THz and a pulsed sub-picosecond THz source with spectral coverage from 0.5 THz to 1.5 THz. The resulting THz detector has a noise equivalent power of 78 fW/Hz1/2 with a timing resolution of 1 ns. χ (2) nonlinear interactions are intrinsically very fast; our temporal bandwidth is limited by the optical detector. Additionally, the THz detector demonstrates a broadband response with a phase-matching bandwidth exceeding 1 THz. This noise equivalent power of 78 fW/Hz 1/2 and the corresponding power conversion efficiency of 1.2× 10 -3 are the best reported, to our knowledge. This paper presents both theoretical and experimental results.
Investigating the mechanisms fuelling reduced false recall of emotional material

We investigated false memory for emotional word lists using the Deese–Roediger–McDermott paradigm. Participants viewed negative, positive, and neutral lists of semantic associates matched on backward associate strength (BAS) and word frequency and recalled as many words as they could remember after each list was presented. Results from two experiments indicated that while participants did create false memories for emotional word lists, neutral lists resulted in the highest false and true recall rates. Experiment 2 used an inclusion task that required participants to recall any words that came to mind and indicate whether the words had actually been presented. The results suggest that emotional words decrease false memories, in part, by encouraging item-specific processing, which consequently impairs the acquisition of relational information and/or the spread of activation to the critical lure.
THE HEDGING EFFECTIVENESS OF FOREIGN CURRENCY FUTURES

This study provides an initial analysis of the hedging potential of the foreign currency futures markets. Numerous studies exist on the pricing efficiency and hedging effectiveness of the foreign currency forward markets, but little research exists on the foreign currency futures market. An adequate price history has only recently become available to carry out such an investigation. Minimum risk hedges and hedging effectiveness measures are presented for five currencies: the British pound, German mark, Canadian dollar, Japanese yen and Swiss franc. Analysis indicates the relative desirability of positions in futures contracts to minimize the risk of spot currency exposure. Results also show hedging effectiveness increases with the investment horizon.
Cotton defoliant runoff as a function of active ingredient and tillage.

Cotton (Gossypium hirsutum L.) defoliant runoff was recently identified as an ecological risk. However, assessments are not supported by field studies. Runoff potential of three defoliant active ingredients, dimethipin (2,3-dihydro-5,6-dimethyl-1,4-dithiin 1,1,4,4-tetraoxide), thidiazuron (N-phenyl-N-1,2,3-thidiazol-5-yl-urea), and tribufos (5,5,5-tributyl phosphorotrithioate) was investigated by rainfall simulation on strip (ST) and conventionally tilled (CT) cotton in south central Georgia. Simulated rainfall timing relative to defoliant application (1 h after) represented an extreme worst-case scenario; however, weather records indicate that it was not unrealistic for the region. Thidiazuron and tribufos losses were 12 to 15% of applied. Only 2 to 5% of the more water soluble dimethipin was lost. Although ST erosion rates were less, loss of tribufos, a strongly sorbing compound, was not affected. Higher sediment-water partition coefficients (kd) were measured in ST samples. This likely explains why no tillage related differences in loss rates were observed, but it is unknown whether this result can be generalized. The study was conducted in the first year following establishment of tillage treatments at the study site. As soil conditions stabilize, ST impacts may change. Data provide an estimate of the maximum amount of the defoliants that will run off during a single postapplication storm event. Use of these values in place of the default value in runoff simulation models used in pesticide risk assessments will likely improve risk estimate accuracy and enhance evaluation of comparative risk among these active ingredients.
Political fortunes: on finance & its regulation

Both during and after bubbles, political outcomes reflect the same forces that operate even in normal times. Such forces include decision-making based on ideologies – free market conservatism, egalitarianism, and populism. Political decisions (and non-decisions) also reflect checks and balances across branches of the federal government, across layers of government in a federal system, and institutional checks, such as bicameralism and filibusters. Interests favoring current arrangements benefit from the status quo bias inherent in our political institutions. How these forces operate is greatly influenced by how ideology has contributed to the polarization between the two major political parties.
Avalanche behavior in the draining of superfluid helium from the porous material Nuclepore

Examination of the primary draining curve in studies of the capillary condensation of ${}^{4}\mathrm{He}$ in the porous material Nuclepore reveals that lowering the chemical potential when the helium is in the superfluid state causes the Nuclepore pore spaces to drain in a series of large-scale avalanches in which substantial numbers of pores (up to $\ensuremath{\sim}2.5%$ of the sample) drain as a single cooperative event, i.e., as an avalanche. In this work we document the behavior of such avalanches in this porous material for two characteristic diameter pore sizes 200 nm and 30 nm. We examine the relevance of various theoretical models which one might apply to the system and conclude that none is completely satisfactory.
Nonoutbreak-related airborne Staphylococcus spp in a veterinary hospital

Background Methicillin-resistant Staphylococcus spp (MRS), such as methicillin-resistant Staphylococcus aureus (MRSA), is a nosocomial pathogen of significant concern. This study evaluates the prevalence and determinants of airborne MRS and methicillin-susceptible Staphylococcus spp (MSS) in a veterinary teaching hospital during periods of no known active clinical cases of Staphylococci infections. Methods Airborne MRS and MRSA were sampled from 10 areas on 3 days each over 3 consecutive months in a veterinary teaching hospital. Each location was sampled twice each day (daytime and evening). Hospital clinical personnel were surveyed for activity levels across the areas sampled. Results Airborne MSS was detected in 52% (25/48) of samples and mecA -confirmed airborne MRS in 12.5% (6/48) of samples. Among daytime air samples, Staphylococcus spp varied by functional area ( P P = .011) with the hallway posing the greatest risk for both. Conclusion Our results indicate that (1) Staphylococcus spp is present in air in clinical environments during periods of no known clinical Staphylococci cases and (2) levels of airborne Staphylococcus spp are associated with functional space and human activity level. Applying these findings to MRSA surveillance creates opportunities for improving the accuracy and precision of exposure classification and risk mitigation.
The mechanics of coating delamination in thermal gradients

Oxide coatings used for various components in the hot section of aero-turbine engines experience temperature gradients at various stages during their flight cycle. One gradient exists during steady-state, due to the combination of the combustion environment next to the free surface and internal cooling of the underlying superalloy substrate. Other gradients develop during cooling of the surface when engine power is reduced. It will be argued that delaminations, when observed within the oxide layer, can only be explained by the presence of a significant stress gradient in the coating, governed by these thermal circumstances. Two extreme cool-down scenarios are envisaged. In one, the surface is cooled suddenly to a lower temperature, followed by slow uniform cooling. In the other, the entire system reduces its temperature uniformly before the temperature gradient in the TBC is eliminated. Criteria for guarding against delaminations within the oxide layer and along the interface with the substrate are provided and the outcome visualized in the form of delamination maps. A comparison with engine experience provides a preliminary assessment of the relevant thermal scenarios, as well as pathways for continuing research.
Shock-induced vaporization of anhydrite and global cooling from the K/T impact

Discovery of abundant anhydrite (CaSO_4) and gypsum (CaSO_4•2H_2O) in the otherwise carbonate sediment comprising the upper 3 km thick layer of the target rock at the K/T impact site has prompted research on these minerals. Evaluation of the severity of the proposed extinction mechanism involving injection of impact-generated SO_2 and SO_3 into the stratosphere entails determination of criteria for shock-induced vaporization of these minerals. In the present work we present new data on the vaporization criteria of anhydrite. These are based on the reanalysis of the shock wave experiments of Yang and Ahrens [Earth Planet. Sci. Lett. 156 (1998) 125–140], conducted on material with 30% porosity, in which the shock- (fully or partially) vaporized sample interacts with an overlying LiF window. The velocity histories, monitored using a velocity interferometer, are compared with numerical simulations employing an improved equation of state for porous anhydrite and its vaporization products. We also employ the ‘entropy criterion’ for vaporization of material under shock compression. The values of the entropies of incipient and complete vaporization for anhydrite are determined to be 1.65±0.12 and 3.17±0.12 kJ (kg K)^(−1), respectively, and the corresponding pressures for incipient and the complete vaporization along the Hugoniot for the solid material are 32.5±2.5 and 122±13 GPa, respectively as compared with 81±7 and 155±13 GPa previously reported by Yang and Ahrens. Along with these criteria, the use of the recent estimate of diameter (100 km) for the Chicxulub transient crater [O’Keefe and Ahrens, J. Geophys. Res. 104 (E11) (1999) 27091–27104; Morgan et al., Nature 390 (1997) 472–476] that is smaller than previously assumed, along with Ivanov et al.’s [Geol. Soc. Am. Spec. Pap. 307 (1996) 125–142] 2-D hydrodynamic simulation to determine the shock attenuation and Pope et al.’s [J. Geophys. Res., 102 (E9) (1997) 21645–21664] radiative transfer model, yields the maximum decrease in the average global surface temperature of 12–19 K for 9.0–9.5 years at the K/T boundary. Thus, the global cooling is inferred to have been less severe than that indicated by the upper limit of the range of 5–31 K decrease lasting for ∼12 years calculated by Pope et al. Because ambient global surface temperatures at K/T time were ∼18–20°C warmer than present values, this cooling event produced cold, but not freezing conditions at the Earth’s surface.
The deformation microstructure of the NiNi4Mo system

Abstract The deformation microstructure of stoichiometric Ni4Mo and of an off-stoichiometric NiNi4Mo alloy are examined via transmission electron microscopy. In general, the Ni4Mo superlattice dislocation does not form in either alloy, although one instance is documented in which the superlattice dislocation was found in the off-stoichiometric alloy. Stacking faults and deformation twins are prevalent in the stoichiometric alloy and in the off-stoichiometric alloy containing large Ni4Mo precipitates. Although twinning is not a preferred deformation mode for many ordered alloys, a twinning mechanism is proposed which explains the prevalence of such twins in the NiNi4Mo alloy system.
Why Convention Dominates Pension Fund Trustee Investment Decisionmaking

Pension funds may be one of the few avenues now open for financing new urban infrastructure and development projects. But convention dominates pension fund trustees' investment decisions, so it is difficult to see how the ambitions of advocates of pension fund investment can be squared with trustees' behaviour. The question is: why does convention dominate? Drawing on previously reported interviews and case studies, I propose a framework through which to understand the dominance of convention. In doing so, I identify a set of behavioural traits that structure decisions. This framework is inspired by the contributions of Kahneman and Tversky and their colleagues for understanding the economic psychology of individual decisionmaking. The paper is intended to be a realistic account of the attributes of trustee decisionmaking, recognising the ingrained and systematic nature of the identified habits, rules, and norms. The paper is also inspired by Keynes's work on risk and uncertainty. In combination, I assess...
High yield fabrication of multilayer polydimethylsiloxane devices with freestanding micropillar arrays

A versatile method to fabricate a multilayer polydimethylsiloxane (PDMS) device with micropillar arrays within the inner layer is reported. The method includes an inexpensive but repeatable approach for PDMS lamination at high compressive force to achieve high yield of pillar molding and transfer to a temporary carrier. The process also enables micropillar-containing thin films to be used as the inner layer of PDMS devices integrated with polymer membranes. A microfluidic cell culture device was demonstrated which included multiple vertically stacked flow channels and a pillar array serving as a cage for a collagen hydrogel. The functionality of the multilayer device was demonstrated by culturing collagen-embedded fibroblasts under interstitial flow through the three-dimensional scaffold. The fabrication methods described in this paper can find applications in a variety of devices, particularly for organ-on-chip applications.
PAGET'S BONE DISEASE: RESPONSE TO HUMAN CALCITONIN IN PATIENTS RESISTANT TO SALMON CALCITONIN

Abstract Of 27 patients (2 with osteoporosis, 25 with Paget's bone disease) treated with salmon calcitonin (S.C.T.) for 10 to 43 months, serum antibodies to S.C.T. were detected in both patients with osteoporosis and in 10 patients with Paget's disease. Human calcitonin (H.C.T.) was available to treat the Paget's disease in 5 of the patients who had demonstrable serum antibodies to S.C.T., and rebound elevations of serum-alkaline-phosphatase and urinary hydroxyproline. Maximum serum-binding capacities for S.C.T. ranged from 2 to 541 μg. per litre. All patients showed a hypocalcaemic response to the acute subcutaneous administration of 0·5 mg. of H.C.T., but only the 2 patients with low serum S.C.T. antibody titres responded to a comparable biological dose of S.C.T. All 5 patients showed significant biochemical improvement during the first 2-3 months of treatment with H.C.T., with reduction of serum-alkaline-phosphatase to 33-50% of pretreatment levels. Human calcitonin can be used successfully to treat patients who are resistant to foreign calcitonins.
Principal Leadership: Creating a Culture of Academic Optimism to Improve Achievement for All Students.

Since the Coleman Report (1966), educational researchers have tried to identify school properties that make a difference in student achievement and overcome the negative influence of low socioeconomic status. We theorized that academic optimism was a latent construct that enhanced student achievement and that enabling school structure provided a mechanism to achieve academic optimism. Forty suburban and rural elementary schools in Ohio provided the sample for this study. Data were collected from the faculty in each school and the hypotheses and model were tested and supported using correlation, regression, and factor analyses.
Net Synthesis of Lecithin in an Isolated Enzyme System

WORK in this Laboratory1 has shown that the biosynthesis of lecithin and of phosphatidyl ethanolamine involves the intermediary formation of cytidine diphosphate choline and cytidine diphosphate ethanolamine. The enzymatic synthesis of lecithin is described in the following simplified scheme:
Ferrous iron uptake by rat duodenal brush border membrane vesicles: Effects of dietary iron level and competing minerals (Zn+2, Mn+2, and Ca+2)

Abstract We sought to confirm a recent report that Fe+2 uptake into rat brush-border membrane vesicles is markedly increased by short-term consumption of iron-deficient diet, with no additional enhancement as the animal becomes functionally iron-deficient with continuing dietary Fe deprivation. In addition, we investigated whether previously observed in vivo absorption interactions of iron, zinc, and manganese occur in the brush border membrane vesicles uptake process, and whether short-term or long-term consumption of an iron-deficient diet affects the interaction at the uptake level. We did not observe any differences in Fe+2 uptake between normal and iron-deficient brush border membrane vesicles, even when the iron status contrast was intensified by feeding a high iron versus iron-deficient diet for 3 weeks. Equimolar Zn+2 and Mn+2 decreased Fe+2 uptake by 29 to 50% and 11 to 39%, respectively. Iron deficiency did not alter these effects. Equimolar Fe+2 decreased Zn+2 uptake by 13 to 22%. Calcium, included as a negative control, did not affect Fe+2 uptake. Thus, some competition between Fe+2 and similar divalent cations does occur at the level of the brush border membrane; the exact nature of this competition remains to be determined.
Appendiceal carcinoma: Patterns of failure following surgery and implications for adjuvant therapy

Background and Objectives Primary adenocarcinoma of the appendix is rare, which makes an understanding of its natural history difficult. To date, it is treated predominantly with surgery alone. This review aims to elucidate the patterns of failure and treatment outcomes when adjuvant treatment is given after primary surgical resection. Methods Twenty-three patients were treated with either surgery alone, or with surgery and adjuvant radiation +/− chemotherapy. A review of the clinical course of these patients was undertaken with an analysis of the local control, distant failure, disease-free survival, and overall survival. Results Most patients presented with local invasion or metastatic disease often involving the peritoneum. Overall survival was 32%, similar to the results of other studies. Analysis of patients with locally advanced disease showed improvement in overall survival and local control with postoperative radiation therapy compared to surgery alone. Conclusions Adenocarcinoma of the appendix is a rare disease that presents most often in an advanced stage. It has been shown by others that a right hemicolectomy provides the best outcome with respect to surgical procedure. Postoperative irradiation appears to provide a benefit for both local control and overall survival. J. Surg. Oncol. 1997;66:51–53. © 1997 Wiley-Liss, Inc.
SIRACUS, an expert system to help inspectors in characterizing detected defects

Abstract The SIRACUS expert system is aimed at assisting the operator in determining the nature of indications detected during ultrasonic testing of pressure vessel welds. Depending on the working conditions and the a priori position of defect, the system proposes a series of scanning directions leading most rapidly towards a ‘volumetric’ or ‘non-volumetric’ diagnosis. The progressively elaborated diagnosis is based on the consideration of numerous parameters such as directional reflectivity, echo shape, echo-dynamical pattern, position with reference to chamfer and working conditions (back gouging, welding technique).
Laparoscopic Hepatectomy for Colorectal Metastases: Ready for Prime Time?

Colorectal metastases represent the most common hepatic malignancy, and experience has shown that surgical resection may offer long-term cure in select patients. Advances in operative technique and adjuvant therapy have increased 5-year survival rates to more than 50%. During the last decade, the introduction of laparoscopic liver resection has progressed from a novelty to a viable surgical option. With the growing enthusiasm for laparoscopic hepatectomy, multiple centers are utilizing a minimally invasive approach to hepatic colorectal metastases. As with any new surgical procedure, several concerns have arisen with laparoscopic hepatectomy. These include the safety of this procedure as well as its oncologic integrity. Despite these concerns, recent series have demonstrated the equivalence of laparoscopic and open hepatectomy for colorectal metastases, resulting in many of these fears being put to rest. Given these promising results, centers that have developed the necessary expertise to safely perform laparoscopic hepatectomy should begin to apply this approach to hepatic colorectal metastases.
The Inbreeding Decline and Average Dominance of Genes Affecting Male Life-History Characters in Drosophila Melanogaster

This paper describes the results of assays of male life-history characters in a large outbred laboratory population of D. melanogaster. Lines of flies homozygous for the entire third chromosome and lines of flies carrying two different third chromosomes were assayed for age-specific male mating ability (MMA), age-specific survivorship, male fertility, and body mass. The results of these assays were used to calculate the inbreeding decline associated with each of these traits, the average dominance of deleterious alleles that affect the traits, the genotypic and environmental components of variance for the homozygous lines, and phenotypic and genotypic correlations among the characters. Significant inbreeding decline was found for all characters except the Gompertz intercept and fertility. Early and late MMA show larger effects of inbreeding than any other trait. The inbreeding load for MMA is about the same magnitude as that for egg-to-adult viability, but is substantially less than that associated with total fitness. The estimated inbreeding decline and average dominance of male life-history characters are comparable to estimates for other Drosophila fitness components.
Adaptation to Natural Binocular Disparities in Primate V1 Explained by a Generalized Energy Model

Sensory processing in the brain is thought to have evolved to encode naturally occurring stimuli efficiently. We report an adaptation in binocular cortical neurons that reflects the tight constraints imposed by the geometry of 3D vision. We show that the widely used binocular energy model predicts that neurons dedicate part of their dynamic range to impossible combinations of left and right images. Approximately 42% of the neurons we record from V1 of awake monkeys behave in this way (a powerful confirmation of the model), while about 58% deviate from the model in a manner that concentrates more of their dynamic range on stimuli that obey the constraints of binocular geometry. We propose a simple extension of the energy model, using multiple subunits, that explains the adaptation we observe, as well as other properties of binocular neurons that have been hard to account for, such as the response to anti-correlated stereograms.
Changing the role of women.

Main currents of the women's movement in the United States are reviewed, with special reference to the socio-industrial conditions that shaped and enforced inferior female status, and to the socio-psychological developments that have propelled today's woman—as they did her suffragist great-grandmother—into an awareness of her powerless position. Transformation of this awareness into a feminist consciousness about myth, assigned cultural role, and avenues of accurate self-concept is described, and political programs for change are discussed and evaluated.
Evaluation of an acetic acid ester of monoglyceride as a suppository base with unique properties

The objective of this investigation was to evaluate an acetic acid ester of monoglycerides made from edible, fully hydrogenated palm oil (AC-70) as a suppository based and compare it with a commercially available semisynthetic base (Suppocire AI®). Benzocaine and miconazole were used as model drugs. Suppositories were prepared by the fusion method. The drug loads in the suppositories were kept at 2% to 5% (wt/wt). In vitro release of drug from the suppositories into Sorensen's phosphate buffer (pH 7.4) was studied using a US Pharmacopeia dissolution apparatus 1 and a spectrophotometer. The melting behavior of the bases and the physical state of the drug in the suppositories were studied using a differential scanning calorimeter (DSC). Powder X-ray diffractometry, was used to study any possible polymorphic changes in the AC-70 base during formulation and storage. In vitro release studies revealed that the release of benzocaine from the AC-70 suppository was substantially slower than that of the commercial AI base. At a 2.5% (wt/wt) benzocaine load, the release of drug from the AC-70 suppositories was found to be linear. This slow and linear release was attributed to the physical property of the base, which forms liquid crystalline phases in the aqueous dissolution medium. The lyotropic, liquid crystalline phase has the ability to incorporate drug into its structure and can control the release kinetics of the drug from such a system. The apparent pH of the release medium (water) was decreased by 1 to 1.5 pH units when the AC-70 base was used. The DSC studies revealed that the melting range of the AC-70 base is 36°C to 38°C, which is ideal for suppository formulations. The results of these studies support the possibility of using this new base for slow-release suppository formulations. This base may be of particular interest for a drug that requires an acidic environment to maintain its activity.
Effects of trypsin on binding of insulin and concanavalin A and on glucose and proline transport in the R3230AC mammary adenocarcinoma

Effects of trypsin treatment on insulin and concanavalin A binding to, and glucose and proline transport in, dissociated R3230AC mammary adenocarcinoma cells were examined. Reduction of binding of 125I-labelled insulin was dependent on the amount of trypsin used, the temperature and the time of the incubation period. Under conditions that reduced insulin binding by greater than 75%, transport of glucose and proline was reduced by less than 15%. Scatchard analysis of insulin binding after trypsin treatment yielded slopes similar to those from cells not exposed to trypsin, assuming either two classes of receptors or an average affinity, Ke. Dissociation of bound insulin from untreated or trypsin-treated cells was enhanced by addition of excess unlabelled ligand. Insulin added in vitro, which decreased glucose transport in untreated cells, produced a decrease in glucose transport in cells treated with trypsin for 5 min (insulin binding was decreased 35%), but not in cells treated for 45 min (insulin binding was decreased 90%). Binding of the plant lectin concanavalin A was also reduced by trypsin treatment, but to a lesser extent and with a different time-course than for insulin. Scatchard analysis of the binding of concanavalin A in untreated and trypsin-treated cells yielded comparable values for Kd. The insulinomimetic actions of concanavalin A on glucose transport were abolished after brief exposure to trypsin. Pre-treatment of cells with concanavalin A reduced insulin binding and partially protected insulin receptors from trypsin digestion, but the inability to remove all of the concanavalin A precluded its use as a method to protect insulin receptors. Thus, in this rat mammary tumor, the number, but not the affinity or functional activity, of insulin receptors can be reduced by trypsin treatment without significant effects on glucose or A system amino acid transport.