cssi/SciSciGPT-SciSciNet huggingface dataset:
Chemical aging and the hydrophobic‐to‐hydrophilic conversion of carbonaceous aerosol

[1] Laboratory experiments simulating chemical aging of carbonaceous aerosol by atmospheric oxidants demonstrate that oxidative processing increases their ability to activate as cloud droplets. A microphysical model shows, however, that the measured increase in hygroscopicity is insufficient to lead to efficient wet scavenging for sub-100 nm particles that are typically emitted from combustion sources. The absence of an efficient atmospheric oxidation pathway for hydrophobic-to-hydrophilic conversion suggests that the fate of carbonaceous aerosol is instead controlled by its interaction with more hydrophilic species such as sulfates, nitrates, and secondary organic aerosol, leading to longer lifetimes, higher burdens, and greater contributions to climate forcing in the free troposphere than are currently estimated.
A probably fast, provably optimal algorithm for rectilinear Steiner trees

We use the technique of divide‐and‐conquer to construct a rectilinear Steiner minimal tree on a set of sites in the plane. A well‐known optimal algorithm for this problem by Dreyfus and Wagner [10] is used to solve the problem in the base case. The run time of our optimal algorithm is probabilistic in nature: for all ϵ > 0, there exists b > 0 such that Prob[T(n) > 2b√n log n]>1–ϵ, for n log n > 1 – ϵ, for n sites uniformly distributed on a rectangle. The key fact in the run‐time argument is the existence of probable bounds on the number of edges of an optimal tree crossing our subdivision lines. We can test these bounds in low‐degree polynomial time for any given set of sites. © 1994 John Wiley & Sons, Inc.
BUCKLING CRITERION FOR LINEAR VISCOELASTIC COLUMNS

T buckling of linear viscoelastic columns has been analyzed in Refs. 1-5. Kempner and Pohle and Hilton demonstrated that a column made of a linear viscoelastic material does not possess a finite critical time. This corrects the result stated by Freudenthal. In all of these cases the column was assumed to have an initial curvature. It is the purpose of this paper to consider the buckling of a perfectly straight, linear viscoelastic column and to apply the buckling criterion described in Refs. 6-10. The well known equation for an initially straight elastic column is
Opponent chromatic response functions for an average observer.

Average opponent chromatic response functions are presented for use in quantitative models of color perception. Theoretical transformations of photopigment input are related to opponent channel activity. Opponent chromatic activity is, in turn, used to describe a theoretical huenaming curve for an average observer.
Social Capital, Social Engineering, and the Technopolis

Summary and discussion Everett Rogers (1962) noted, “All innovation takes placewithin a social system.” Because voluntary organizations havedone so much to instigate and drive technopolis initiativesworldwide, social capital is of paramount importance to allregions aiming to create a social support structure for tech-nology entrepreneurs (Phillips 2009). This paper has cata-logued elements of social capital that are relevant to technop-olis designers. Few of its assertions have been subjected tostatistical testing. Rather, they are based on the author’s longexperience, on cases in the literature, and on many technop-olis officials’ observed willingness to put them into use.Successful technopoleis are metropolitan regions, and ulti-mately become networks of metropolitan regions (Gibsonand Kozmetsky 1993; Phillips 2007). That is, with few excep-tions (e.g., compact countries such as Israel and Singapore),technopoleis do not co-extend with national boundaries. Yetin many instances technopolis initiatives are launched bynational governments. This usually implies a difficult socialpolicy in which resources are funneled to already-advantagedregions, i.e., regions most likely to be the core of successfultechnopoleis. This geographically “unbalanced” economicgrowth within a nation, ultimately benefits all. National gov-ernments must learn to tolerate and support this trend, andexplain it to the electorate, despite that it appears to be athreat to the relevance of the nation-state itself.Pockets of interest are not only defined in terms of geog-raphy. Why do we build technopoleis? It is to ensure a futureflow of new wealth via innovation, and the purposes of com-monwealth are social betterment and political self-determi-nation for the region. (One needs only to recall the uproarin the US when, in the 1980s, Japanese concerns bought upa number of American landmarks, in order to understandthe psychological and nationalistic basis of the drive towardself-determination. Indeed this sentiment was the basis ofthe American Revolution of 1776. Much economic coloniza-tion still occurs in the world, to the detriment of local popu-lations who would prefer not to be colonized.) A workshop
Relativistic long-range potentials from non-integer oscillator strength sums

Abstract The coefficient W4 of the leading relativistic correction to longrange interatomic potentials is shown to be simply related to the oscillator strength sum S(− 1 2 ). Upper bounds and estimates for W4 are given for all pairs of the atoms H, He, Ne, Ar, Kr, and Xe.
The Interannual Variability of Tropical Precipitation and Interhemispheric Energy Transport

AbstractThe interannual variability of the location of the intertropical convergence zone (ITCZ) is strongly (R = 0.75) correlated with the atmospheric heat transport across the equator (AHTEQ) over the satellite era (1979–2009). A 1° northward displacement of the ITCZ is associated with 0.34 PW of anomalous AHTEQ from north to south. The AHTEQ and precipitation anomalies are both associated with an intensification of the climatological Hadley cell that is displaced north of the equator. This relationship suggests that the tropical precipitation variability is driven by a hemispheric asymmetry of energy input to the atmosphere at all latitudes by way of the constraint that AHTEQ is balanced by a hemispheric asymmetry in energy input to the atmosphere.A 500-yr coupled model simulation also features strong interannual correlations between the ITCZ location and AHTEQ. The interannual variability of AHTEQ in the model is associated with a hemispheric asymmetry in the top of the atmosphere radiative anomalies ...
Measuring the geometrical size of multiparticle processes

Abstract We examine the possibility of measuring the geometrical size of multiparticle processes. The mean-square impact parameter, 〈 b 2 〉, of a process can be estimated by means of lower bounds which are determined from experiment. A bound of this type, which has been proposed by Webber, is found to be inadequate for the estimate. We propose several alternative bounds. One of them represents a considerable improvement over Webber's bound, with essentially no increase in the difficulty of the measurement. Another is a theoretically optimal bound which, however, requires an extremely high-statistics experiment. We also describe a method of deriving further bounds; and make estimates of the difference between the bounds and the true 〈 b 2 〉.
An Easy Reduction of an Isoperimetric Inequality on the Sphere to Extremal Set Theory

In ancient times the extent of a city or an armed camp was often given in terms of its perimeter (so that a town would be described as requiring so many thousand paces to walk round). In the same way, according to Proclus, certain socialistic communities used to divide land so that each family received a plot of equal perimeter and it may have been in this context that it was first realised that a square contains a much greater area than a long thin rectangle of the same perimeter. Once it was understood that figures with the same perimeter may contain different areas, it was natural to ask whether there exists a figure of maximum area. It is not hard to guess that the answer is a circle, but a guess is not a proof. The isoperimetric problem thus asks for a proof that among all figures of equal perimeter the circle has greatest area.-T. W. Korner [3, ?35] The classical isoperimetric problem described by Korner has been dazzlingly generalized in numerous directions and the term is now used to describe a variety of conceptually similar problems. One particularly satisfying aspect of the study of such inequalities is the synergistic relationship between combinatorial and continuous cases of the problem. Indeed, in this note, we show how a combinatorial isoperimetric inequality on the n-hypercube HI, = {O, i} naturally gives rise to a continuous version on the n - 1 sphere. The specific question we explore is that of the largest volume that a (measur
Another look on bond market seasonally: a note

Abstract This note provides evidence that there exists business cycle effects on the monthly returns of long-term government bond and low-grade corporate bond. In addition, the results of the Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models suggest that the returns series exhibit significant autoregressive conditional heteroskedasticity.
Secure degrees of freedom in MIMO cognitive radio systems

We study the secure degrees of freedom (DoF) in a cognitive radio system. A cognitive radio user helps to secure primary user's transmission against an eavesdropper and in return, primary users allows secondary user to access its licensed spectrum. All users are equipped with multiple antennas. We investigate the secure DoF using interference alignment concept with partial channel state information (CSI). When eavesdropper is interested only in primary user's data, it is shown that if all users, including primary transmitter-receiver pair, secondary transmitter-receiver pair and eavesdropper, have M antennas, achievable secure DoF d p and DoF d s of primary and secondary users, respectively, satisfy 2d p ≤ M and d s ≤ M − 2d p .
Penicillin-nonsusceptible pneumococcus in acute otitis media in New York City.

Abstract Objective: To determine the proportion of children with acute otitis media (AOM) presenting in our catchment area in New York City who were infected with nonsusceptible Streptococcus pneumoniae and to determine the susceptibility of these organisms to penicillins and other antibiotics commonly used to treat AOM. Setting: Ambulatory clinics and the emergency department of a tertiary care, inner-city medical center. Patients: During a 2-year period from 1993 to 1995, 115 children (aged 6 months to 12 years) with AOM underwent tympanocentesis. Patients did not receive antibiotics for at least 1 week before tympanocentesis. Results: Thirty-one children were infected with S pneumoniae, and 83.9% of isolates were susceptible to penicillin. Of the 16.1% strains that were nonsusceptible, most (4 of 5 strains) were intermediately resistant, and only 1 exhibited high-level resistance to penicillin. Of all the cephalosporins tested, only cefotaxime had consistent activity against the intermediately resistant strains. Notably, all nonsusceptible pneumococci were inhibited by macrolides. Conclusions: This study provides unique reference data for nonsusceptible Streptococcus pneumoniae in children with AOM and documents that newer cephalosporin agents are not active against all of these strains. (Otolaryngol Head Neck Surg 1999;121:27-30.)
Ultrastructural analysis of projections to the pulvinar nucleus of the cat. II: Pretectum.

The pretectum (PT) can supply the pulvinar nucleus (PUL), and concomitantly the cortex, with visual motion information through its dense projections to the PUL. We examined the morphology and synaptic targets of pretecto-pulvinar (PT-PUL) terminals labeled by anterograde transport in the cat. By using postembedding immunocytochemical staining for γ-aminobutyric acid (GABA), we additionally determined whether PT-PUL terminals or their postsynaptic targets were GABAergic. We found that the main projection from the PT to the PUL is an ipsilateral, non-GABAergic projection (72.4%) that primarily contacts thalamocortical cell dendrites (87.6%), and also the dendritic terminals of interneurons (F2 profiles; 12.4%). The PT additionally provides GABAergic innervation to the PUL (27.6% of the ipsilateral projection), which chiefly contacts relay cell dendrites (84.6%) but also GABAergic profiles (15.4%). These GABAergic pretectal terminals are smaller, beaded fibers that likely branch to bilaterally innervate the PUL and dLGN, and possibly other targets. We also examined the neurochemical nature of PT-PUL cells labeled by retrograde transport and found that most are non-GABAergic cells (79%) and devoid of calbindin. Taking existing physiological and our present morphological data into account, we suggest that, in addition to the parietal cortex, the non-GABAergic PT-PUL projection may also strongly influence PUL activity. The GABAergic pretectal fibers, however, may provide a more widespread influence on thalamic activity.
A critical review of growth of low-dimensional carbon nanostructures on SiC (0 0 0 1): impact of growth environment

Graphene and carbon nanotube (CNT) structures have promise for many electronic device applications and both have been grown on SiC through the decomposition of the substrate. It is well known that both graphene and aligned CNTs are grown under similar conditions with overlapping temperature and pressure ranges, but a fundamental understanding of the two types of growths is actively being researched. Moreover, various technical challenges need to be overcome to achieve improvement in the electronic and structural quality of these carbon-based nanostructures on SiC. Specifically, an understanding and control of the SiC surface graphitization process and interface structure needs to be established. In this review, we focus on graphene growth on SiC (0 0 0 1) (Si-face) as a model system in comparison with aligned CNT growth on SiC. The experimental growth aspects for graphene growth, including vacuum and ambient growth environments, and growth temperature are summarized, then proposed decomposition and growth mechanisms are discussed. Both thermal and chemical decomposition processes are presented and special emphasis is given to the role of growth process variations between laboratories. The chemical reactions driving the graphitization process and ultimately the carbon nanostructure growth on SiC are discussed. It is suggested that the composition of the residual gases in the growth environment is a critical parameter and that gas composition at the growth temperature should be monitored.
An analysis of tropical cyclones impacting the Southeast United States from a regional reanalysis

Extreme events (low probability–high impact events) such as tropical cyclones can result in loss of life, substantial socio-economic impacts and disrupt the natural environment. Atmospheric reanalysis products provide a means for understanding these events and their impacts. This paper examines the near-surface winds and precipitation from 42 observed land-falling tropical cyclones between 1979 and 2000 in a new high-resolution (10 km) reanalysis for the Southeast United States. It is shown that the near-surface wind speeds in the tropical cyclones are underestimated by almost half compared to the observed best-track data. The regional reanalysis resolves the pattern of coastal precipitation associated with the tropical cyclones; however, the average storm maximum precipitation is too high resulting in large storm-related precipitation farther inland than observed. Possible reasons for the deficiencies are discussed.
Myelin, DIGs, and membrane rafts in the central nervous system

Over the past 40 years our understanding of the organization of cell membranes has changed dramatically. Membranes are no longer viewed as a homogenous sea of phospholipids studded with randomly positioned islands of proteins. Our current view of the membrane involves the formation of small lipid clusters, comprised mainly of cholesterol and sphingolipids, known as membrane rafts. These lipid clusters apparently include and exclude specific proteins leading to the hypothesis that these domains (1) regulate cellular polarity and compartmentalization through trafficking and sorting, (2) provide platforms for cellular signaling and adhesion, and (3) function as cellular gate keepers. Tremendous controversy surrounds the concept of membrane rafts primarily because these small, highly dynamic entities are too small to be observed with traditional microscopic methods and the most utilized approach for raft analysis relies on poorly quantified, inconsistent biochemical extractions. New analytical approaches are being developed and applied to the study of membrane rafts and these techniques provide great promise for furthering our understanding of these enigmatic domains. In this review we will provide a brief summary of the current understanding of membrane rafts, utilizing the CNS myelin literature for illustrative purposes, and present caveats that should be considered when studying these domains.
Identifying antecedents of information exchange within supply chains

Although information exchange among trading partners is consistently mentioned as a key requirement of successful supply chain management implementation, research on information exchange is scarce. This lack of research provides little guidance and support for those managers interested in improving their logistics operations through increased information exchange. The main goal of this paper is to identify potential antecedents of information exchange. Questionnaires were sent to logistics managers at manufacturing firms in several industries. The results of this exploratory study are detailed and the implications for logistics managers discussed.
Freedom with a Buddhist Face

This article clarifies the Buddhist position on freedom and responsibility, while arguing for three central claims. The first is that it is an open question whether Buddhists endorse causal determinism or causal indeterminism. The second claim is that the most promising contemporary interpretations of the Buddhist view fail in important respects. The final claim is that the best interpretation of the Buddhist position on freedom and responsibility is Buddhist Perspectivalism, the view that we should view ourselves as genuinely free and responsible, while viewing others as neither free nor responsible.
Electrodynamics of the equatorial evening ionosphere: 1. Importance of winds in different regions

The importance of winds at different altitudes and latitudes for the electrodynamics of the low-latitude evening ionosphere is examined with a model of the global coupled ionosphere-thermosphere system. The model reproduces the main observed features of the evening equatorial plasma vortex and the prereversal enhancement (PRE) of the vertical drift. The electrodynamics is driven primarily by the zonal wind forced by the diurnally varying zonal pressure-gradient force. The zonal wind lags the zonal pressure-gradient force owing to inertia. When ion drag is important, the time lag of the wind behind the pressure gradient force is shortened, and the high-altitude evening wind turns eastward earlier than the wind at lower altitudes, where ion drag is less important. Therefore, a vertical shear of the zonal wind tends to develop at altitudes around the transition between small and large ion drag at the bottom of the F region. This wind shear is closely associated with the vertical shear in the zonal convection velocity that is part of the evening plasma vortex. Unlike previous studies, we find that the winds driving the PRE lie mainly on field lines with apexes above the peak of the equatorial F layer, field lines that extend in magnetic latitude out to nearly 30° and encompass the entire evening equatorial ionization anomaly region. Contrary to previous suggestions, the westward convection in the bottomside of the evening plasma vortex is found to weaken, rather than strengthen, the PRE. Daytime winds have relatively little influence on the low-latitude evening electrodynamics.
Cardiac arrest and bedside ultrasonography: A survey of practicing emergency physicians

Study objectives: Physicians make decisions to terminate resuscitative measures during cardiac arrest according to several criteria. If ultrasonography is available in the emergency department, this modality is used frequently in the setting of cardiac arrest. When the physician visualizes absent cardiac motion through echocardiography, it may prompt him or her to terminate resuscitative efforts. Our hypothesis is that emergency physicians terminate resuscitative efforts sooner with visualization of cardiac standstill and feel more comfortable in doing so. Methods: We surveyed graduates of our residency program who received training in ultrasonography during their term of residency. Surveys were mailed to 172 practicing emergency physicians who had graduated after 1993. Results: One hundred twenty-seven (73%) surveys were returned. Fourteen physicians responded that they had not been trained in ultrasonography. The remaining 113 surveys (89%) made up the study cohort. During training, the majority of individuals reported that they had used ultrasonography during more than 10 cardiac arrests. It was used for documentation of cardiac activity and pericardial effusions. Ninety percent of individuals used the ultrasonography as an aid in deciding to terminate resuscitative efforts during cardiac arrest, and 60% believed it shortened their resuscitation time. Since graduation, almost 48% of individuals in this study have ultrasonography available in their clinical practice. These individuals stated that they were comfortable in terminating resuscitations without ultrasonography (8.7 on a 10-point visual scale: range 3 to 10). There remains a belief among these individuals that the use of ultrasonography would shorten their “code time” (62%) but that without it they can operate at a comparable standard of care (73%). For those with access to ultrasonography, the majority (44%) use it in more than 76% of their cardiac arrest situations. Ultrasonography is used in these scenarios to shorten the code time (63%), to reassure and confirm the presence of cardiac standstill for the physician (87%), and for the resuscitation team (59%). Conclusion: Bedside ultrasonography is a useful modality in the setting of cardiac arrest. The majority of physicians who use it believe that it shortens code times through visualization of cardiac standstill. However, fewer than 50% of the physicians who were trained in ultrasonography during residency at our institution have access to ultrasonography in their daily practice.
Differential binding properties of oripavines at cloned μ- and δ-opioid receptors

This study examines the possibility that oripavine opioid receptor agonists bind equally to both high and low affinity states of the mu-opioid receptor. Studies were performed in C6 cells expressing mu- or delta-opioid receptors; high and low agonist affinity states of the receptors were defined by the absence and presence, respectively of Na+ ions and the GTP analog Gpp(NH)p. At the mu-opioid receptor dihydroetorphine and etorphine were full agonists, buprenorphine had moderate efficacy while diprenorphine was an antagonist. At the delta-opioid receptor, dihydroetorphine, etorphine, and diprenorphine had moderate efficacy while buprenorphine was an antagonist. The binding affinities of the oripavines at the mu-opioid receptor decreased only one to 2-fold in the presence of NaCl and Gpp(NH)p. In contrast, decreases in oripavine affinity at the delta-opioid receptor correlated with delta-opioid receptor efficacy. The ability of oripavine agonists to bind with high affinity to the low agonist affinity state of the nu-opioid receptor may explain the high potencies of these compounds in vivo.
On the use of secondary structure in protein structure prediction: a bioinformatic analysis

The amount of structural information encoded in secondary structure can be measured by its ability to specify the correct peptide backbone conformation of protein chains. Using methodology derived from information theory, we generate optimized distributions of backbone phi – psi dihedral angle pairs given either correct or predicted three-state secondary structure. Entropy measurements on these distributions provide a means to determine the effect of secondary structure knowledge on identifying the actual 3D conformation of protein chains. We find that only a modest fraction of the total uncertainty in phi – psi conformation (from 14 to 38%, at 20 – 908 resolutions, respectively) is resolved even with perfect knowledge of secondary structure. We further show that prediction of secondary structures, because of an accuracy ceiling below 80%, degrades structural information substantially. If prediction accuracy is below 50%, virtually no advantage is gained from using the prediction. Moreover, even state-of-the-art prediction accuracy of 75% retains less than one-third of the structural information encoded in secondary structure. We demonstrate that the level of structural description affects the amount of information extracted. The effort to provide as much structural detail as possible, while faced with a limited structural data set, results in an optimum resolution in the vicinity of a 208partition of the ðf;cÞ plane. We show that structural information increases exponentially with prediction accuracy, revealing that even marginal gains in the performance of secondary structure prediction algorithms are important for the retention of structural information. We observe that different kinds of secondary structure prediction outputs (single-state prediction, single-state prediction with a confidence index, and three-state probability prediction) do not differ greatly in the amount of structural information they yield, so long as the methods formulated in this work to generate propensity distributions are applied appropriately. The optimal phi – psi probability distributions developed here may be useful in biasing searches in structure space. We discuss the sources of the degradation of information caused by errors in secondary structure prediction, and their consequences for the prediction of the 3D conformation of protein chains. q 2003 Elsevier Ltd. All rights reserved.
Absence of immediate transfer of training of duration symbolic-matching-to-sample in pigeons

Two experiments examined the performance of pigeons on symbolic-matching-to sample in which the relevant sample dimension consisted of duration. Each pigeon was trained on two problems that had the same two sample durations, 2 and 10 sec, but were different with respect to other physical properties of the samples. Durations of light and tone were used in Experiment 1; durations of two different color-location compounds were used in Experiment 2. In each experiment, a unique choice stimulus was associated with each of the four possible combinations of duration and signal type. Test sessions contained probe trials in which the choice stimuli were these appropriate for a long and a short duration of the signal type opposite to that actually presented. Pigeons in both experiments displayed asymmetrical performance deficits. Accuracy on long durations dropped to chance or below, whereas accuracy on short durations remained high. This pattern is similar to the choose-short effect that is obtained when animals are tested with long retention intervals. The implications of these results for duration memory, coding, and transfer of training are discussed.
Magnetic resonance imaging of the liver: How I do it

The present paper provides a brief overview of the rationale behind magnetic resonance imaging (MRI) techniques, a description of the most common sequences used, and a general approach to performing liver MRI.
Sensory innervation of the external and internal genitalia of the female rat

Using a whole-nerve recording method, the genitalia of the female rat were found to receive afferent innervation as follows. Pelvic nerve: vagina, cervix, and perineal skin; hypogastric nerve: cervix and proximal three fifths of the uterus; pudendal nerve: skin of perineum, inner thigh, and clitoral sheath. It is probable that the pudendal and pelvic nerves are activated during copulation, and that all 3 nerves are activated during parturition.
The Best of Both Worlds: How Kinship Care Impacts Reunification:

Children entering out-of-home placement because of parental substance abuse often are placed with relatives. Placements with relatives reduce the likelihood of reunification, but little information is available about why this is the case. Using a multiple embedded case study design, interviews with 26 women and 20 professionals explored the ways kinship care influences reunification among African American women with histories of addiction. The results revealed three kinds of kinship arrangements that influenced whether women regained or permanently lost custody of their children: (a) family support with parameters, (b) limited family support, and (c) enabling family support. These findings suggest a need for child welfare agencies to help relative caregivers establish boundaries and limits particularly when substance abuse is an issue.
Regulation of proliferation of rat mammary tumor cells by inhibitors of cyclooxygenase and lipoxygenase.

Abstract The studies described herein were undertaken with the objective of determing the effect of modulation of arachidonic acid metabolism on proliferation of rat mammary tumor cells in culture. The TMT-081 rat mammary tumor cell line was shown to metabolize [ 14 C]arachidonic acid to thromboxane B 2 , PGE 2 , PGF 2α , and 12- and/or 15-HETE. Furthermore, synthesis of these eicosanoids was physiologically significant since each metabolite stimulated DNA synthesis. Both cyclooxygenase and lipoxygenase inhibitors suppressed cell growth and modulated eicosanoid synthesis in a concentration-dependent manner. Thin layer chromatography showed that the production of cyclooxygenase metabolites (thromboxane B 2 , PGE 2 and PGF 2α ) by TMT-081 cells was inhibited by indomethacin, ibuprofen, BW755C and timegadine. The lipoxygenase inhibitor NDGA was also shown to inhibit thromboxane B 2 synthesis, but increased PGE 2 and PGF 2α syntheses; esculetin, a lipoxygenase inhibitor in other systems, increased all the cyclooxygenase products. The production of the lipoxygenase products 12- and/or 15-HETE was inhibited by NDGA, increased by indomethacin and ibuprofen, but not affected by esculetin, BW755C and timegadine in this cell line. Changes in eicosanoid profile were observed before drug-induced inhibition of cell growth suggesting that the balance of the various eicosanoids may be a critical determinant of cell proliferation. However, since drug-induced effects on arachidonic acid profile occurred at concentrations lower than that necessary for inhibition of cell growth, the effects of these inhibitors on other biochemical pathways affecting cell growth cannot be ruled out.
Use of the computerized tomographic scan in the diagnosis and treatment of abscesses

Abstract Over a 5 year period, 89 patients underwent one or more computerized tomographic scans to locate an abscess during 92 hospitalizations. The scans were a most sensitive (93 percent), specific (98 percent), and accurate (96 percent) means of abscess detection. Thirty-nine patients had positive scans. Sixteen patients were treated directly by open surgical methods, 1 of whom required percutaneous drainage in the postoperative period for incomplete drainage. An additional 23 patients underwent attempted percutaneous abscess drainage. In 17 patients, drainage was successful. Five patients underwent percutaneous drainage and later required laparotomy, two of whom underwent unavoidable surgical procedures and three surgery for incomplete drainage. Overall, percutaneous abscess drainage was successful in 83 percent. Of 11 deaths, 8 occurred in the group with computerized tomographic scans negative for abscess. Three of these were false-negative scans. Three deaths occurred in the group with scans positive for abscess. All were of patients with hepatic abscesses treated by open surgical drainage, one after failed percutaneous drainage. Twelve patients had multiple organ failure, and 8 of these patients died, for a mortality of 67 percent. The computerized tomographic scan is the diagnostic procedure of choice in the diagnosis of abscesses. In selected patients, percutaneous abscess drainage is also a successful means of abscess treatment and avoids the complications of a laparotomy. The onset of multiple organ failure in the surgical patient should alert the diagnostician to the possibility of a septic focus. The role of early laparotomy in these patients is uncertain. We recommend early use of the computerized tomographic scan in the septic surgical patient. Prompt diagnosis and treatment of abscesses, whether by open or percutaneous routes, may avert the development of multiple organ failure and reduce morbidity and mortality.
The Economics of Bipartisan Campaign Reform

This essay evaluates two provisions in the Bipartisan Campaign Reform Act (BCRA): raising contribution limits and banning soft money. The model highlights the importance of marginal cost ratios for candidates and their parties. The results suggest that raising contribution limits protects incumbents. Importantly, this generates efficiency gains that come at the expense of electoral competitiveness. When a party has an advantage in a large number of districts, the soft money ban may also reduce rent-seeking effort while exacerbating existing advantages. Ultimately, the two provisions underscore an “equity-efficiency” trade-off. While restricting rent-seeking effort, they probably lead to less competitive elections.
Rats' responses to molar and local schedule constraints

Three experiments explored responses to molar and local schedule constraints. Thirsty rats pressed a lever for access to a water spout. In Experiment 1, response totals were unaffected by two local schedule characteristics—the variability of the instrumental requirement and the variability of the magnitude of contingent reward. Experiment 2 manipulated the correlation between the instrumental requirement and the magnitude of reward. This correlation did not affect the behavioral price ratio (presses per lick) at a molar level. At a local level, the positive correlation created a lower mean lick price than did the negative correlation. The rats licked more, and licked less efficiently, under the positive correlation than under the negative correlation. Experiment 3 compared two ways of manipulating the molar presses/lick ratio: The instrumental (contingent) series varied the instrumental (contingent) requirement, but held the other requirement constant. As the ratio increased, total leverpresses increased, and total licks decreased linearly; the two series did not differ significantly. At higher lick prices, the rats licked more efficiently and made more extra licks at the spout as it closed. The results help delimit the applicability of molar models of the organism’s response to schedule constraints.
Maps of Central Visual Space in Ferret V1 and V2 Lack Matching Inputs from the Two Eyes

In the visual cortex, the representation of central visual space is supplied by matching geniculate inputs that are driven exclusively by one eye or the other. In layer 4 of early visual areas (V1 in primates and V1 and V2 in cat), these inputs form a nearly uniform array of small ocular dominance domains, while preserving overall topographic order within the cortical map. In ferret, however, ocular dominance domains in different regions of the visual cortex are strikingly irregular in size and shape. The exceptionally large size of domains in some regions implies a departure from the usual visuotopic matching of inputs from the two eyes. Using optical-imaging, electrophysiological, and anatomical techniques, we show that this regional variation is attributable to exclusively monocular maps of the central portions of the ipsilateral visual field in V1 and the contralateral visual field in V2. In addition, we document a complex interdigitation of V1 and V2 that entails a discontinuity in the mapping of visual space and fragmentation of V2 into isolated cortical territories. We suggest that both the monocularity of these cortical maps and the visuotopic discontinuity along the V1–V2 border derive from asymmetries in the crossed and uncrossed retinal pathways.
Design Limits When using Gold-Aluminum Bonds

Gold-aluminum wire bonds form intermetallic phases with any elevated temperature treatment. Intermetallic formation alone does not cause bond failure. However, certain failure modes--open metallization in the bond area, lifted wire bonds after aging, and heel breaks after thermal cycling--may be related to intermetallic formation. Specific causes of these failure modes are discussed. These form the basis for the recommendations presented as design limits when using gold-aluminum wire bonds in circuits.
Symptomatic and incidental thromboembolism are both associated with mortality in pancreatic cancer

Pancreatic cancer is known to be associated with VTE, but contemporary rates of incidental and symptomatic VTE events and their association with mortality are incompletely understood. We conducted a retrospective cohort study of consecutive pancreatic adenocarcinoma patients at the University of Rochester from 2006–2009. Data were analysed using a Cox model with time-dependent covariates. A total of 1,151 radiologic exams of 135 patients were included. Forty-seven patients (34.8%) experienced VTE including 12 pulmonary emboli (PE), 28 deep-vein thromboses (DVTs) and 47 visceral vein events. Incidental events comprised 33.3% of PEs, 21.4% of DVTs and 100% of visceral VTE. Median (95% CI) conditional survival beyond three months was 233 (162–322) more days for those without VTE, which was significantly greater than 12 (3–60) days for those with DVT as first event (p<0.0001) and 87 (14–322) days with visceral first events (p=0.022). In multivariate analysis, DVT (HR 25, 95% CI 10–63, p <0.0001), PE (HR 8.9, 95% CI 2.5–31.7, p = 0.007) and incidental visceral events (HR 2.6, 95% CI 1.6–4.2, p =0.0001) were all associated with mortality, though anticoagulants reduced these risks by 70% (26–88%, p = 0.009). In conclusion, VTE occurs in over one-third of contemporary pancreatic cancer patients and, whether symptomatic or incidental, is strongly associated with worsened mortality. The role of anticoagulation in treating incidental or visceral VTE warrants further study.
Dermal-Resident versus Recruited γδ T Cell Response to Cutaneous Vaccinia Virus Infection

The study of T cell immunity at barrier surfaces has largely focused on T cells bearing the αβ TCR. However, T cells that express the γδ TCR are disproportionately represented in peripheral tissues of mice and humans, suggesting they too may play an important role responding to external stimuli. In this article, we report that, in a murine model of cutaneous infection with vaccinia virus, dermal γδ T cell numbers increased 10-fold in the infected ear and resulted in a novel γδ T cell population not found in naive skin. Circulating γδ T cells were specifically recruited to the site of inflammation and differentially contributed to dermal populations based on their CD27 expression. Recruited γδ T cells, the majority of which were CD27+, were granzyme B+ and made up about half of the dermal population at the peak of the response. In contrast, recruited and resident γδ T cell populations that made IL-17 were CD27−. Using a double-chimera model that can discriminate between the resident dermal and recruited γδ T cell populations, we demonstrated their divergent functions and contributions to early stages of tissue inflammation. Specifically, the loss of the perinatal thymus-derived resident dermal population resulted in decreased cellularity and collateral damage in the tissue during viral infection. These findings have important implications for our understanding of immune coordination at barrier surfaces and the contribution of innate-like lymphocytes on the front lines of immune defense.
Sort vs. Hash revisited: fast join implementation on modern multi-core CPUs

Join is an important database operation. As computer architectures evolve, the best join algorithm may change hand. This paper re-examines two popular join algorithms -- hash join and sort-merge join -- to determine if the latest computer architecture trends shift the tide that has favored hash join for many years. For a fair comparison, we implemented the most optimized parallel version of both algorithms on the latest Intel Core i7 platform. Both implementations scale well with the number of cores in the system and take advantages of latest processor features for performance. Our hash-based implementation achieves more than 100M tuples per second which is 17X faster than the best reported performance on CPUs and 8X faster than that reported for GPUs. Moreover, the performance of our hash join implementation is consistent over a wide range of input data sizes from 64K to 128M tuples and is not affected by data skew. We compare this implementation to our highly optimized sort-based implementation that achieves 47M to 80M tuples per second. We developed analytical models to study how both algorithms would scale with upcoming processor architecture trends. Our analysis projects that current architectural trends of wider SIMD, more cores, and smaller memory bandwidth per core imply better scalability potential for sort-merge join. Consequently, sort-merge join is likely to outperform hash join on upcoming chip multiprocessors. In summary, we offer multicore implementations of hash join and sort-merge join which consistently outperform all previously reported results. We further conclude that the tide that favors the hash join algorithm has not changed yet, but the change is just around the corner.
An Overdose of Slavery

When one compares ancient and modern economic institutions, the differences are many and deep. One of the most obvious is the appearance of slavery virtually everywhere among those societies that rose from simple village life to civilization. Social and economic specialization, the resulting necessity for interchange of goods, and a higher political organization in a firm, consciously organized state—these are aspects of the appearance of civilization, and with them one usually finds a spectrum of social classes from aristrocrats to slaves.
Use of a bioassay to evaluate the toxicity of beauvericin to bacteria

An agar diffusion bioassay was used to compare the sensitivities of bacteria to the mycotoxin beauvericin. Bacillus pumilus LACB101 was inhibited by filter-paper disks containing 0.1 μg of beauvericin; B. cereus, B. mycoides, B. sphaericus, Paenibacillus alvei, P. azotofixans, P. macquariensis, and P. pulvifaciens by 1 μg; and P. validus by 25 μg. The anaerobes Eubacterium biforme, Peptostreptococcus anaerobius, P. productus, Bifidobacterium adolescentis, and Clostridium perfringens were also inhibited by beauvericin.
Molecular imaging of endogenous and exogenous chromophores using ground state recovery pump-probe optical coherence tomography

We present a novel molecular imaging technique which combines the 3-D tomographic imaging capability of optical coherence tomography with the molecular sensitivity of pump-probe spectroscopy. This technique, based on transient absorption, is sensitive to any molecular chromophore. It is particularly promising for the many important biomarkers, such as hemoglobin, which are poor fluorophores and therefore difficult to image with current optical techniques without chemical labeling. Previous implementations of pump-probe optical coherence tomography have suffered from inefficient pump-probe schemes which hurt the sensitivity and applicability of the technique. Here we optimize the efficiency of the pump-probe approach by avoiding the steady-state kinetics and spontaneous processes exploited in the past in favor of measuring the transient absorption of fully allowed electronic transitions on very short time scales before a steady-state is achieved. In this article, we detail the optimization and characterization of the prototype system, comparing experimental results for the system sensitivity to theoretical predictions. We demonstrate in situ imaging of tissue samples with two different chromophores; the transfectable protein dsRed and the protein hemoglobin. We also demonstrate, with a simple sample vessel and a mixture of human whole blood and rhodamine 6G, the potential to use ground state recovery time to separate the contributions of multiple chromophores to the ground state recovery signal.
Comparison of water and saltwater movement in mortar based on a semi empirical electromagnetic model

The presence of chloride ions in steel-reinforced structures leads to the corrosion of the reinforcement thus compromising the integrity and strength of the structure. Thus, it is of great interest to nondestructively detect and evaluate free chloride content in concrete. To this end, an investigation was initiated where two mortar cubes were soaked in distilled water and saltwater solutions, respectively. Their temporal microwave reflection properties were measured using open-ended rectangular waveguides on a daily basis for three cycles, each lasting 35 days. Subsequently, a semiempirical electromagnetic model was developed to simulate the reflection properties of the cubes. The outcome of the model describes the water and saltwater distribution within the cubes. In addition, these distributions depict the manner by which the water and saltwater content temporally vary within the cubes. The presence of salt causes the saltwater distribution to be different than the water distribution in the respective cubes. This paper presents a comparison between the water and saltwater distributions obtained from this model. The results of such a comparison would then indicate the influence of salt on the mechanism of mass transport within the saltwater cube.
Analysis and design of hierarchical Web caching systems

This paper aims at finding fundamental design principles for hierarchical Web caching. An analytical modeling technique is developed to characterize an uncooperative two-level hierarchical caching system where the least recently used (LRU) algorithm is locally run at each cache. With this modeling technique, we are able to identify a characteristic time for each cache, which plays a fundamental role in understanding the caching processes. In particular, a cache can be viewed roughly as a lowpass filter with its cutoff frequency equal to the inverse of the characteristic time. Documents with access frequencies lower than this cutoff frequency will have good chances to pass through the cache without cache hits. This viewpoint enables us to take any branch of the cache tree as a tandem of lowpass filters at different cutoff frequencies, which further results in the finding of two fundamental design principles. Finally, to demonstrate how to use the principles to guide the caching algorithm design, we propose a cooperative hierarchical Web caching architecture based on these principles. The simulation study shows that the proposed cooperative architecture results in 50% saving of the cache resource compared with the traditional uncooperative hierarchical caching architecture.