cssi/SciSciGPT-SciSciNet huggingface dataset:
Coupled active shape models for automated segmentation and landmark localization in high-resolution CT of the foot and ankle

Purpose: We develop an Active Shape Model (ASM) framework for automated bone segmentation and anatomical landmark localization in weight-bearing Cone-Beam CT (CBCT). To achieve a robust shape model fit in narrow joint spaces of the foot (0.5 – 1 mm), a new approach for incorporating proximity constraints in ASM (coupled ASM, cASM) is proposed. Methods: In cASM, shape models of multiple adjacent foot bones are jointly fit to the CBCT volume. This coupling enables checking for proximity between the evolving shapes to avoid situations where a conventional single-bone ASM might erroneously fit to articular surfaces of neighbouring bones. We used 21 extremity CBCT scans of the weight-bearing foot to compare segmentation and landmark localization accuracy of ASM and cASM in leave-one-out validation. Each scan was used as a test image once; shape models of calcaneus, talus, navicular, and cuboid were built from manual surface segmentations of the remaining 20 scans. The models were augmented with seven anatomical landmarks used for common measurements of foot alignment. The landmarks were identified in the original CBCT volumes and mapped onto mean bone shape surfaces. ASM and cASM were run for 100 iterations, and the number of principal shape components was increased every 10 iterations. Automated landmark localization was achieved by applying known point correspondences between landmark vertices on the mean shape and vertices of the final active shape segmentation of the test image. Results: Root Mean Squared (RMS) error of bone surface segmentation improved from 3.6 mm with conventional ASM to 2.7 mm with cASM. Furthermore, cASM achieved convergence (no change in RMS error with iteration) after ~40 iterations of shape fitting, compared to ~60 iterations for ASM. Distance error in landmark localization was 25% to 55% lower (depending on the landmark) with cASM than with ASM. The importance of using a coupled model is underscored by the finding that cASM detected and corrected collisions between evolving shapes in 50% to 80% (depending on the bone) of shape model fits. Conclusion: The proposed cASM framework improves accuracy of shape model fits, especially in complexes of tightly interlocking, articulated joints. The approach enables automated anatomical analysis in volumetric imaging of the foot and ankle, where narrow joint spaces challenge conventional shape models.
Plasma optics for intense laser amplification

Laser amplification through plasma-based techniques might overcome the thermal damage limit of conventional materials, thereby enabling the next generation of laser intensities. The leading plasma-based method is Raman compression: a long laser pump decays into a plasma wave and a counterpropagating short laser seed pulse, which, capturing the pump energy, reaches extreme intensities. The technological requirements on the seed are severe: it must be very sharp and matched properly in frequency. To sharpen the seed pulse, we propose a laser-controlled, super-fast plasma shutter technique, analogous to electromagnetically induced transparency (EIT) in atoms. We further show that the laser seed may even be replaced by a stationary plasma wave seed. In the important pump-depletion regime, the plasma-wave initiated output pulse approaches the self-similar attractor solution for the corresponding laser seed, with the frequency match automatic. These techniques also work with partially coherent pumps. Actually, a partially coherent pump can even advantageously suppress the noise-seeded spontaneous Raman amplification which is responsible for premature pump depletion.
DABs are inorganic carbon pumps found throughout prokaryotic phyla

Bacterial autotrophs often rely on CO2 concentrating mechanisms (CCMs) to assimilate carbon. Although many CCM proteins have been identified, a systematic screen of the components of CCMs is lacking. Here, we performed a genome-wide barcoded transposon screen to identify essential and CCM-related genes in the γ-proteobacterium Halothiobacillus neapolitanus. Screening revealed that the CCM comprises at least 17 and probably no more than 25 genes, most of which are encoded in 3 operons. Two of these operons (DAB1 and DAB2) contain a two-gene locus that encodes a domain of unknown function (Pfam: PF10070) and a putative cation transporter (Pfam: PF00361). Physiological and biochemical assays demonstrated that these proteins-which we name DabA and DabB, for DABs accumulate bicarbonate-assemble into a heterodimeric complex, which contains a putative β-carbonic anhydrase-like active site and functions as an energy-coupled inorganic carbon (Ci) pump. Interestingly, DAB operons are found in a diverse range of bacteria and archaea. We demonstrate that functional DABs are present in the human pathogens Bacillus anthracis and Vibrio cholerae. On the basis of these results, we propose that DABs constitute a class of energized Ci pumps and play a critical role in the metabolism of Ci throughout prokaryotic phyla.
Exploring Alternatives to Cash Bail: An Evaluation of Orange County’s Pretrial Assessment and Release Supervision (PARS) Program

This evaluation examines the impact of a pretrial risk assessment and supervised release program on pretrial release rates, judicial bail determinations, and failure to appear (FTA) rates among non-violent felony defendants in Orange County, CA. The results indicate that program implementation was not associated with a significant increase in pretrial release rates. However, defendants who received supervised release under the program were significantly less likely to FTA than similarly situated defendants who were released on cash bail. The results therefore suggest that pending bail reform measures in California and elsewhere, which replace cash bail with risk assessment screening and non-monetary supervised release, can be implemented without sacrificing appearances in court.
The preventive role of cardiorespiratory fitness in current male smokers who meet the American Cancer Society criteria for lung cancer screening: a prospective pilot study

Survival benefits could be potentially improved by adding cardiorespiratory fitness (CRF) to lung cancer screening. The current pilot study aimed to assess the association between CRF and adverse outcomes in current male smokers who are meeting the American Cancer Society (ACS) criteria for lung cancer screening. A total of 260 men with a baseline CRF assessment (treadmill exercise test) who are met the ACS lung cancer screening criteria (“current smokers aged 55–74 years with ≥ 30 pack/years smoking history”) were prospectively studied. Cox proportional hazard models were analyzed for all-cause and cancer mortality, total and lung cancer incidence. Mean age was 63.3 ± 5.4 years, smoking history 50.4 ± 26.7 pack/years, and CRF was 7.8 ± 3.2 metabolic equivalents (METs). During a mean of 10.2 ± 6.1 years follow-up, 80 participants developed any type of cancer, 19 were diagnosed with lung cancer and 66 died (cancer, n = 39, other causes, n = 27). In multivariable models, only CRF was associated with all-cause and cancer mortality. Each 1-MET higher CRF was associated with a 10% reduced risk for all-cause mortality [0.9, 95% CI (0.83 to 0.98), p = 0.017] and cancer mortality [0.9, 95% CI (0.8 to 0.99), p = 0.048]. CRF was not associated with total cancer incidence (p = 0.59) or lung cancer incidence (p = 0.96). Higher CRF is independently associated with lower risk of all-cause and cancer mortality in current male smokers who meet the ACS criteria for lung cancer screening. Screening for CRF and achieving higher CRF levels could potentially reduce mortality and serve as complementary preventive strategy in heavy smokers.
Irreversible electroporation is a thermally mediated ablation modality for pulses on the order of one microsecond.

Abstract Irreversible electroporation (IRE) is generally considered to be a non-thermal ablation modality. This study was designed to examine the relative effect of temperature on IRE ablation sizes for equivalent dose treatments with constitutive pulses between 1 and 100 µs. 3D in-vitro brain tumor models maintained at 10 °C, 20 °C, 30 °C, or 37 °C were exposed to 500 V treatments using a temperature control algorithm to limit temperature increases to 5 °C. Treatments consisted of integrated energized times (doses) of 0.01 or 0.1 s. Pulse width, electrical dose, and initial temperature were all found to significantly affect the size of ablations and the resulting lethal electric field strength. The smallest ablations were created at 10 °C and ELethal were calculated to be 1729, 1359, 929, 777, 483 V/cm for 0.01 s treatments with 1, 2, 4, 8, and 100 µs pulses, respectively. At 37 °C these values decreased to 773, 614, 507, 462, and 394 V/cm, respectively. Increasing the dose from 0.01 to 0.1 s at 37 °C resulted in statistically significant decreases (p
18F-FDG PET/CT for Systemic Staging of Newly Diagnosed Triple Negative Breast Cancer (TNBC)

617 Objectives : National Comprehensive Cancer Network guidelines consider 18F-FDG PET/CT for systemic staging of newly diagnosed stage III breast cancer patients, but not earlier stages. However factors in addition to stage may influence PET/CT utility. As breast cancers that are negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor (triple negative breast cancer, TNBC) are more aggressive and metastasize earlier than other breast cancers, we hypothesized that receptor expression may be one such factor. This study assessed PET/CT for systemic staging of newly diagnosed TNBC. Methods In this Institutional Review Board approved retrospective study, our Hospital Information System was screened for patients with TNBC who underwent PET/CT in 2007-2013 prior to systemic or radiation therapy. Initial clinical stage was determined from mammography, ultrasound, and magnetic resonance imaging, and/or surgery, if performed prior to PET/CT. PET/CT was evaluated to identify unsuspected extra-axillary regional nodal and distant metastases, as well as unsuspected synchronous malignancies. Upstaged proportions were calculated. Results 232 patients with TNBC met inclusion criteria. PET/CT revealed unsuspected distant metastases in 30 (13%): 0/23 initial stage I, 4/82 (5%) stage IIA, 13/87 (15%) stage IIB, 4/23 (17%) stage IIIA, 8/14 (57%) stage IIIB, and 1/3 (33%) stage IIIC. In addition, 5 unsuspected synchronous malignancies were identified. Conclusions 18F-FDG PET/CT revealed distant metastases in 15% of patients with initial clinical stage IIB TNBC, which suggests this subgroup of patients should be considered for systemic staging with 18F-FDG PET/CT at initial diagnosis. Receptor status of the breast malignancy may be one characteristic important in determining subgroups of patients who could benefit from PET/CT systemic staging at initial diagnosis.
FX Liquidity and Market Metrics: Online Appendices 1 and 2

Online appendices for FX Liquidity and Market Metrics (https://ssrn.com/abstract=2912976 or DOI:10.2139/ssrn.2912976). Appendix 1 contains expanded tables and figures. Appendix 2 describes reconciliation and comparison of the CLS settlement data with other sources (BIS and EBS).
Looking Back at Other People’s Money: A Qualitative Test of Cressey’s Classic Hypothesis of Trust Violating Behavior

Cressey’s study of trust violators has had a tremendous impact on how criminologists understand white collar offenders. Despite this, few have sought to replicate or validate his findings. The aim of this study is to replicate Cressey’s classic work to determine if it still has practical theoretical value today. To do this, we relied on data collected from 25 male federally incarcerated occupational offenders using semi-structured interviews. The results indicate that there is moderate empirical support for Cressey’s hypothesis when collectively examining all three components of his hypothesis. We found only minimal support for the importance of “non-shareable problems” because about half of the participants did not mention such issues. We did find strong evidence supporting the importance of verbalizations (i.e., neutralizations) in allowing for these crimes to occur. Overall, these findings suggest that more research needs to be conducted in order to determine why non-shareable problems do not seem to be as important now as they once were for the commission of occupational crimes such as embezzlement.
Inside the nothingness

Space-time may seem empty, but the expanse between stars is filled with more interesting stuff than you may think, writes Chanda Prescod-Weinstein
CMPyMOL: An Interactive PyMOL extension for Protein Contact-Map Analysis

Abstract Contact–maps are reduced 2D representation of the 3D spatial configuration of a protein. Many valuable structural features like secondary structures, inter- and intra-protein interactions,interacting domains, etc., can be readily identified from these maps. However, it is not straightforward and intuitive to reckon the spatial organization of the contact regions from reduced representation. The CMPyMOL extention for molecular visualization software PyMOL attempts to bridge this gap as an interactive graphical tool for protein contact-maps that interfaces with PyMOL for 3D visualization. Specifically, CMPyMOL helps understand the functional importance of contacts by providing visual overlays of various structural and biochemical properties of a protein on top of its contact-map.
Order Ahead for Pickup: Promise or Peril?

Quick-service restaurants have been increasingly enabling customers to order ahead---placing orders on demand remotely so that orders can be prepared while customers travel to the service facility for pickup. It is widely believed that the order-ahead scheme reduces delay and therefore attracts more orders (i.e., yields higher throughput) than if customers must order onsite. We build queueing-game theoretic models to study the throughput and welfare implications of order-ahead. Contrary to conventional wisdom, the order-ahead model commonly used in practice that locks in orders as they come in may yield lower throughput than the order-onsite model, and in fact, may create a lose-lose outcome for both the service provider and customers when the service provider optimally chooses the queue information provision policy to maximize throughput. We examine two alternative order-ahead schemes that can potentially mitigate the throughput deficiency. The first approach rejects new orders at the outset if there are already too many outstanding ones; the second approach allows customers to cancel their orders in the process if they so choose. While both approaches can restore the throughput superiority of order-ahead over order-onsite, neither is able to always dominate the plain order-ahead model that does not support rejection or cancellation, suggesting complementary strengths of the three order-ahead schemes.
Hospitality: How a Biblical Virtue Could Transform United States Immigration Policy

Despite the lack of attention paid to immigration policy as a moral issue during the 2006 Congressional elections, the intense debate which has arisen around this issue since that time confirms that the United States' policies, laws, and practices towards non-citizens do in fact raise a whole host of moral and ethical concerns about which many Americans feel very strongly. This article considers how interjecting these moral values into the debate on the United States' admittedly broken immigration system could lead to reforms that are at once workable and humane. The article also calls into question the failure of the Christian right to give equal time to this particular set of core religious values calling for fairness and justice for the alien, in their efforts to shape national immigration policy. Part II of the article describes the long tradition of hospitality to the stranger found in the narratives of both the Hebrew Bible and New Testament, a tradition requiring all people to extend welcome, equal protection, and justice to the alien in their midst. Part III addresses the ways in which these narratives from diverse religious traditions can and should contribute to and enrich the current debate over immigration reform. Finally, Part IV offers three specific examples of how United States immigration law and policy might be brought more in line with these moral and ethical mandates to show hospitality to the stranger, and how doing so could lead to a more just and effectual immigration system. This article is based on a presentation given at a conference, Strangers No Longer: Immigration Law and Policy in the Light of Religious Values, sponsored by the Fordham University Law School Institute on Religion, Law & Lawyer's Work.
COVID-19 testing among children, parental preferences for testing venues and acceptability of school-based testing: a survey of US parents

In a national survey of 2,074 US parents conducted in March 2021, 35.9% reported their youngest child had been tested at least once for COVID-19. Parents preferred testing venue choice was the pediatricians office. Only half of parent surveyed (50.6%) reported that they would allow their child to be tested for COVID-19 at school/daycare if it was required.
Diffusion along perivascular spaces reveals evidence supportive of glymphatic function impairment in Parkinson disease.

Abstract Background Reduced diffusion along perivascular spaces in adults with Alzheimer's-disease-related-dementias has been reported and attributed to reduced glymphatic function. Objectives To apply quantitative measures of diffusion along, and orthogonal to, perivascular spaces in a cohort of older adults with and without clinical symptoms of alpha-synuclein related neurodegeneration. Methods 181 adults with Parkinson disease (PD) or essential tremor (ET) additionally sub-classified by the presence of cognitive impairment underwent 3 T MRI. Diffusion-tensor-imaging (spatial resolution = 2x2x2 mm; b-value = 1000 s/mm2; directions = 33) measures of diffusion (mm2/s) parallel and orthogonal to perivascular spaces at the level of the medullary veins, and the ratio of these measures (ALPS-index), were calculated. Regions were identified by a board-certified neuroradiologist from T1-weighted and T2-weighted MRI. Evaluations of motor impairment and mild cognitive impairment (MCI) were interpreted by a board-certified neurologist and neuropsychologist, respectively. Multiple regression with false discovery rate correction was applied to understand how diffusion metrics related to (i) disease category (PD vs. ET), (ii) cognition (MCI status), and (iii) white matter disease severity from the Fazekas score. Results The ALPS-index was reduced in PD compared to ET participants (p = 0.037). No association between the ALPS-index and MCI status, but an inverse association between the ALPS-index and Fazekas score (p = 0.002), was observed. The ALPS-index was inversely associated with age (p = 0.007). Conclusion Diffusion aberrations near perivascular spaces are evident in patients with alpha-synuclein related neurodegenerative disorders, and are related to age and white matter disease severity.
How Business Interest Groups Matter: Rare Event Modeling of Green Building Policy in Cities

This research distinguishes among the business interest groups and community factors associated with green building policies in cities and towns to examine a specific type of business interest grou...
Point-of-Care Ultrasound as a Tool to Assess Wound Size and Tissue Regeneration after Skin Grafting.

Chronic wounds can be difficult to heal and are often accompanied by pain and discomfort. Multiple skin substitutes or cellularized/tissue-based skin products have been used in an attempt to facilitate closure of complex wounds. Allografts from cadaveric sources have been a viable option in achieving such closure. However, early assessment of graft incorporation has been difficult clinically, often with delayed evidence of failure. Visual cues to assess graft integrity have been limited and remain largely superficial at the skin surface. Furthermore, currently used optical imaging techniques can penetrate only a few millimeters deep into tissue. Ultrasound (US) imaging offers a potential solution to address this limitation. This work evaluates the use of US to monitor wound healing and allograft integration. We used a commercially available dual-mode (US and photoacoustic) scanner operating only in US mode. We compared the reported wound size from the clinic with the size measured using US in 45 patients. Two patients from this cohort received an allogenic skin graft and underwent multiple US scans over a 110-d period. All data were processed by two independent analysts; one of them was blinded to the study. We measured change in US intensity and wound contraction as a function of time. Our results revealed a strong correlation (R2 = 0.81, p 91% was seen in both patients after skin grafting. An inverse relationship between wound size and US intensity (R2 = 0.77, p < 0 .0001) indicated that the echogenicity of the wound bed increases as healthy cells infiltrate the allograft matrix, regenerating and leading to healthy tissue and re-epithelization. This work indicates that US can be used to measure wound size and visualize tissue regeneration during the healing process.
The Selfie in Consumer Culture

This chapter analyzes the selfie from interdisciplinary perspectives, focusing on the selfie as branding tool. I draw upon conceptions of the selfie as commodity form and aesthetic practice to analyze the selfie as a complex and provocative visual element in contemporary branding. The selfie’s incessant focus on identity mirrors the corporate embrace of identity as a core branding component. Further, as selfies generally appear within branded social media platforms, the logic of branding pulses through them, as they serve to draw attention to websites, capture data, and create clickstreams. Considering how brands appropriate, deploy, and promote selfies provides insight into the flows between high and low forms of visual culture, in particular, into how photography– and self-portraiture – interacts with, supports, and enhances corporate strategy, and how visual trends articulate certain assumptions about consumer culture and social media. I argue that digital self-portraiture cannot be understood without reference to branding and strategic communication.
Do interest groups unduly influence bank regulation

It is well known that banks in countries around the world play a key role in allocating resources that are essential to economic growth and development. It is also well known that banks do not always allocate resources to the most productive projects based on both risk and return considerations. This was the case during the recent global financial crisis when some banks engaged in such excessively risky and less productive activities that they either failed or were bailed out. The severity of the crisis underscores the need for governments to put in place bank regulatory regimes that prevent such deplorable episodes.
Experimental Models and Clinical Tools to Assess Nerve Regeneration and Functional Outcomes

The success of vascularized composite allotransplantation (VCA) is dependent on adequate peripheral nerve regeneration for optimal outcomes. Because so much of the benefit derived from VCA is derived from peripheral nerve regeneration, systematically monitoring this process clinically is of utmost importance, particularly with regards to determining prognosis. As such, more attention must be placed on developing new strategies to enhance peripheral nerve regeneration and graft innervation. The clinical evaluation of nerve regeneration can be complex due to the multiple problems that nonfunctioning nerves may cause. Indeed, a nonfunctional nerve does not only cause problems from absence of function but may impart unique impairment from pain, sympathetic, and/or sudomotor dysfunction. Therefore, evaluation of nerve regeneration should combine functional testing, patient outcome reported testing, and more objective neurophysiologic and/or imaging-based testing. This chapter provides an overview of the experimental as well as clinical methodologies available for the evaluation of peripheral nerve repair and regeneration with special attention placed on nerve regeneration in the setting of VCA.
Bioluminescence: From Chemical Bonds to Photons

The biological transformation of chemical to photic energy involves an enzyme-mediated chemiluminescent reaction, in which one of the products exists in an electronically excited state, emitting a photon as it returns to the ground state. The colour of bioluminescence differs in different organisms, ranging from the deep blue (460 nm) of certain crustacea, through the bluish green (490 nm) of some bacteria, the green (530 nm) of mushrooms to the red (about 600 nm) of the railroad worm. In one case, energy transfer has been demonstrated from the enzyme system to material that emits light with a longer wavelength. The energies involved range from about 165 to 250 kJ/einstein (40 to 60 kcal/einstein). Boyle first showed that air was involved in bioluminescence in 1668 in his experiments with an air pump. Over the past 100 years, it has become clear that most if not all bioluminescent systems require molecular oxygen. The recent isolation and characterization of an oxygen-containing (peroxide) enzyme intermediate from the bacterial system is described and a reaction mechanism is postulated. This scheme is compared with other hypothetical mechanisms, in particular those involving a four-membered ring intermediate, a dioxetane, in which the simultaneous cleavage of two bonds leaves one product in an excited state. I shall discuss the special role of luciferases in bioluminescence, especially in flashing mechanisms involving 'precharged' intermediates.
An overview of pheochromocytoma: history, current concepts, vagaries, and diagnostic challenges

Tragically as many as 50% of pheochromocytomas are discovered at autopsy, mainly because the diagnosis of this neuroendocrine tumor was not considered. Missing the diagnosis almost invariably results in devastating cardiovascular complications or death. Clinicians must always think of pheochromocytoma whenever evaluating a patient with sustained or paroxysmal hypertension or any manifestations suggesting hypercatecholaminemia. Very rarely, familial pheochromocytomas may cause no hypertension, symptoms, or signs. But biochemical testing can always establish the presence or absence of a pheochromocytoma, and localization with magnetic resonance imaging, computed tomography, or 131I or 123I-MIBG is almost always possible.
Ground Interpolation for Combined Theories

We give a method for modular generation of ground interpolants in modern SMT solvers supporting multiple theories. Our method uses a novel algorithm to modify the proof tree obtained from an unsatifiability run of the solver into a proof tree without occurrences of troublesome "uncolorable" literals. An interpolant can then be readily generated using existing procedures. The principal advantage of our method is that it places few restrictions (none for convex theories) on the search strategy of the solver. Consequently, it is straightforward to implement and enables more efficient interpolating SMT solvers. In the presence of non-convex theories our method is incomplete, but still more general than previous methods.
Evaluating the Intergranular SCC Resistance of Sensitized Type 304 Stainless Steel in Low-Temperature Water Environments

The resistance of sensitized AISI Type 304 stainless steel to intergranular stress-corrosion cracking (IGSCC) in 32/sup 0/C water environments has been investigated using constant axial load (CAL), constant extension rate (CER), U-bend and crevice corrosion tests. Constant load tests were found to give a better simulation of a service failure and produced IGSCC under a wider range of conditions than CER or U-bend tests. Intergranular SCC of welded and furnace-sensitized Type 304 specimens was observed in CAL experiments in both deionized and borated water with ppM level chloride additions. Constant extension rate tests also produced IGSCC but only in welded pipe specimens with the original ground and welded surfaces intact. If the original ID and OD surfaces were removed, fracture surfaces showed ductile, microvoid coalescence appearances. No evidence of SCC or significant corrosive attack was found in U-bend or crevice corrosion tests after more than six months in dilute chloride environments at temperatures of 30 or 50/sup 0/C. However, intergranular cracking was observed in furnace-sensitized, high-carbon Type 304 U-bend specimens at 80/sup 0/C.
Effects of Fuel Properties on Soot Formation in Turbine Combustion

A T-63 combustor rig was used to study the sensitivity of combustor performance to the physical and chemical properties of fuels in order to determine the effectiveness of fuel properties as correlating parameters for soot formation in gas turbine engines. The composition, the distillation curve, and viscosity were of special concern, the first property associated with carbon formation chemistry and the latter two related to the effect of mixing on atomization and vaporization. Six fuels blended from a JP-5 base fuel were used to determine the effects of aromatic content, aromatic types, and end point. Three JP-5's derived from coal, shale oil, and tar sands were used to examine correlation with petroleum-derived fuels. Seven other fuels that were blends of marine diesel, JP-5, and gasoline were used for overall evaluation, but with emphasis on viscosity and distillation curve. Four emulsified fuels containing 5%, 10%, 20%, and 30% water were prepared with one of the above high aromatic JP-5 fuel blends; two more emulsified fuels containing 10% and 20% water were prepared with the shale oil-derived JP-5. The combustor was instrumented for flame radiation, exhaust smoke, and gaseous emissions, all measured at full power. The hydrogen/carbon ratio was the most effective correlating parameter for radiation and smoke; sensitivities to molecular structure appeared to be secondary. Similar to the syncrude fuels, the water/fuel emulsions and methanol/aromatic blends correlated in the same way as petroleum fuels. Higher end points did not affect the correlation, indicating that soot formation was due to gas phase reactions and not liquid phase pyrolysis. The results favor a chemical mechanism for the role of water in reducing soot.
Electron multiplier response under positive ion impact: I. Secondary electron emission coefficients

Abstract Secondary electron emission coefficients deduced from the impact of atomic, diatomic and poiyatomic ions in the 2–10 keV kinetic energy range impinging on the first dynode of a twenty dynode electron multiplier have been determined under standard mass spectrometer detection conditions. As the studies were made on gas covered surfaces, kinetic emission dominated. The theory of Parilis and Kishinevskii described the atomic results by accounting for the linear dependence of the emission coefficient with impact ion velocity, the dependence of the slope of the linear region on the nature of the impacting ion and a constant intercept velocity for all atomic ions, 0.4 × 107 cm sec−1, as determined by extrapolating the linear section of the efficiency versus velocity plots to the threshold for the process. Diatomic and polyatomic ions were more efficient producers of secondary electrons than atomic ions, but required a factor of two higher threshold velocity on the average than did atomic ions. The increased efficiency is examined and does not appear related, in the energy range examined, to complete decomposition of the molecule at the target. It is alternatively suggested that surface rather than interpenetration effects account for the difference in electron emission efficiency for molecules as compared to that for atoms.
Regulation of human natural killing. IV. Role of lipoxygenase in regulation of natural killing activity.

In this study we demonstrated that natural killer (NK) cell lysis by human peripheral blood nonadherent (NA) cells against K562 target cells was rapidly inhibited by four agents that inhibit the lipoxygenase pathway of arachidonic acid metabolism, nordihydroguaiaretic acid (NDGA), U-60257, α-phenanthroline, and esculetin. However, human NK cells activated by interferons (IFN) or poly I:C were partially resistant to suppression by NDGA and U-60257. Pretreatment of the NA cells with the four lipoxygenase inhibitors at 37°C for 18 h led to suppression of NK activity. The inhibition of NK activity by NDGA was not reversed by aspirin at a concentration that inhibits PGE2 synthesis. Thus, suppression of NK activity by NDGA was not mediated by the effects on PGE2 synthesis. However, the inhibition of endogenous NK activity by NDGA, U-60257, α-phenanthroline, or esculetin was partially reversed by IFN or poly I:C. These results suggest that products of lipoxygenation are required for maintenance of human NK activity.
The Transition Period in Restructuring High Schools: Teachers as Leaders.

The dynamics precipitated among teachers and other staff members during the organizational transition period of a school's restructuring affect the way people do their jobs and, no less significant, the way they view and work with each other and with school administrators to achieve school goals. The period of time between the initial decision to abandon the old organization and the integration of the new one into the daily thinking and behaviors of all members in the school community is the period of organizational transition. How many high school restructuring initiatives march forward like Napoleon into Russia, ready to change the world, only to freeze and starve in the wintry marshes of institutionalized gridlock? Ignoring or neglecting the special needs of faculty and staff when the school organization is in transition may be the reason why so many high school restructuring efforts fail or, at best, have limited success. Can teachers play a leadership role in helping the school navigate the turbulent shoals of the transition period? I think they can. In fact, if the reforms implemented by the school are to be long lasting, the leadership of teachers is essential. A successful organizational transformation means more than replacing the traditional curriculum departments or the principal as the school's sole decision-maker. It also means raising the professional consciousness of teachers so that they can assume new roles. Strong and effective leadership by teachers during the transition period can remove a great deal of the uncertainty that currently plagues restructuring high schools. It can improve the school climate and, logically, people's responsiveness to new ideas, thereby
Refractive index of AlGaInN alloys

The refractive index of quaternary nitride alloys is calculated for the transparent ultraviolet to green wavelength range (370-565 nm) by nonlinear interpolation of binary alloy parameters measured. Results given as function of composition for different substrates show strong deviations from linear interpolations.
Acute and chronic increases in osmolality increase excitatory amino acid drive of the rostral ventrolateral medulla in rats

Water deprivation is associated with increased excitatory amino acid (EAA) drive of the rostral ventrolateral medulla (RVLM), but the mechanism is unknown. This study tested the hypotheses that the...
High-germanium-content SiGe islands formed on compliant oxide by SiGe oxidation

The oxidation of Si1−xGex islands on a compliant viscous borophosphorosilicate glass (BPSG) was utilized to achieve nearly fully relaxed Si1−xGex with germanium content up to 57%. After Si1−xGex islands were formed on BPSG by layer transfer, dry oxidation was carried out to form pure silicon dioxide on the top and to increase germanium content in the Si1−xGex layer. Surface roughening and the nonuniformity of the enhanced germanium content during the SiGe oxidation were improved by depositing a silicon dioxide capping layer before oxidation. The strain arising from the increase of germanium content was relaxed by lateral expansion of the SiGe islands, showing that dislocations were not required in the process.
The Waste Isolation Pilot Plant Site: An International Center of Excellence

The United States Department of Energy's Carlsbad Field Office (CBFO) is responsible for the successful management of transuranic radioactive waste (TRUW) in the United States. TRUW is a long-lived radioactive waste/material (LLRM). CBFO's responsibilities includes the operation of the Waste Isolation Pilot Plant (WIPP), which is a deep geologic repository for the safe disposal of U.S. defense-related TRUW and is located 42 kilometers (km) east of Carlsbad, New Mexico. WIPP is the only deep-geological disposal site for LLRM that is operating in the world today. CBFO also manages the National Transuranic Waste Program (NTP), which oversees TRU waste management from generation to disposal. As of February 2003, approximately 1500 shipments of waste have been safely transported to the WIPP, which has been operating since March 1999.
Does price rigidity cause large social or private costs

Nominal rigidity is a necessary condition for nominal disturbances to cause aggregate output fluctuations. The paper studies whether price rigidity can entail a large social welfare loss far beyond the resulting private loss in a general setting with many (endogenous) monopoly firms and a representative consumer-worker. Numerical simulation finds that the social welfare cost of rigidity is increasing in the concavity of the economy's welfare function. This positive relationship, however, cannot guarantee the social cost to dominate the private cost. Rather, the former turns out smaller than the latter for a wide range of parameter values, in contrast to most recent work. The implication is that gains from stabilization policy may be negligible.
Insulin resistance and hypertension: new insights

Insulin resistance is associated with hypertension. Nakamura et al. demonstrate in rodents and humans with insulin resistance that while the stimulatory effect of insulin on glucose uptake in adipocytes, mediated via insulin receptor substrate 1 (IRS1), was severely diminished, its effect on salt reabsorption in the kidney proximal tubule, mediated via IRS2, was preserved. Compensatory hyperinsulinemia in individuals with insulin resistance may enhance salt absorption in the proximal tubule, resulting in a state of salt overload and hypertension.
Comment on: the mean value of the W/sub u/ statistic

In a test to identify the uniform distribution, S.W. Cheng and F.A. Spiring (IEEE Trans. Reliability, vol. R-36, p.98, Apr. 1987) develop some theoretical results associated with the W/sub u/ test statistic. The central values obtained by their formula do not fit the quantiles of W/sub u/. The present authors derive three approximations for finding the mean value of W/sub u/ and compare the results with those of Cheng and Spiring. A table of simulated values of W/sub u/ is given. >
Effect of platelet-rich plasma with autogenous bone graft for maxillary sinus augmentation in a rabbit model

Purpose To evaluate the effect of platelet-rich plasma (PRP) on autogenous bone graft remodeling during sinus augmentation in a rabbit model. Materials Twelve New Zealand White rabbits were divided randomly into 3 groups based on their time of sacrifice (2, 4, and 8 weeks). All animals underwent a general anesthetic and harvesting of an autogenous bone graft from the right iliac crest with subsequent bilateral maxillary sinus augmentation. PRP was prepared via standard approved technique by acquiring 21 cc of autogenous blood and performing differential centrifugation to obtain PRP. One cc of PRP was produced that was mixed with bovine topical thrombin and calcium chloride. The left maxillary sinus received only autogenous bone, while the right maxillary sinus received a mixture of PRP mixed with autogenous bone, thus each animal acted as its own control. Equal volumes of bone were inserted in each maxillary sinus. Animals were sacrificed at 2, 4, and 8 weeks and all specimens were harvested for peripheral quantitative computed tomography (pQ-CT), static, and dynamic and histomorphometric analysis. Results Student t tests were performed comparing bone density via pQ-CT analysis, histomorphometric parameters of total bone area, and bone apposition rate. PRP had no statistically significant effect on bone graft healing in maxillary sinus augmentation when compared using standard pQ-CT, static, and dynamic histologic criteria. Conclusion This study fails to find a direct stimulatory effect of PRP on healing of autogenous bone grafts using pQ-CT, static, and dynamic histomorphometric analyses.
THE POLYMORPHIC PATTERN OF SOMATOMEDINS DURING DEVELOPMENT

Human somatomedins (Sm) show considerable heterogeneity on separation by chromatofocusing (CF). Besides the major forms eluting at pI=8.3 (IGF7I/SmC) and at pI=6.3 (IGF-II) a number of minor peaks emerge which can be classified as IGF-I-like or as IGF-II-like. The aim of the current study was to investigate, whether there is an age-dependence of the polymorphic pattern during human development. Serum (2ml) extracts from children (n=157 and adults (n=9) where fractionated by HPLC-CF. The fractions were screened for Sm-like peptides by CPBA. The total Sm-activity of the various peaks was quantitated either by a specific IGF-I/SmC-RIA or by a IGF-II-RIA giving their relativ contribution to total IGF-I/SmC and IGF-II immunoactivity resp. The results show that the various Sm-like peptides are present in all age groups studied. Although serum IGF-I/SmC rises considerably at the time of puberty, the ratio of the various IGF--I/SmC-like peptides to total IGF-I/SmC-IR did not vary. There was a small but significant increase of the two very basic Sms (pI=9.2 and pI-8.7) from 3.4% at puberty to 6.7% (p<0.002) in adults and from 9.3% to 14.5% (p<0.02) resp. The major component at pI=8.3 decreased accordingly from 83.1% to 72.0% (p<0.01). When CPBA-active peaks were tested for IGF-II-like peptides, a rather broad peak at pI=8.1 contained an unexpectedly high amount of IGF-II-like material (x=21.1%). The relative contributions of the various other IGF-II-like components to total IGF-II-IR were 4.5% (pI=6.7). 36.7% (pI=6.3), 14.6% (pI=6.15), 3.2% (pI=6.0), and 19.6% (salt Peak) without any significant difference between age groups. These results demonstrate, that heterogeneity of somatomedins is a common phenomenon through9ut human development with some age-dependence for IGF-I/SmC-like peptides and no obvious age-dependence with IGF-II-like components.
Reaction Pathways and Energetics of Etheric C–O Bond Cleavage Catalyzed by Lanthanide Triflates

Efficient and selective cleavage of etheric C–O bonds is crucial for converting biomass into platform chemicals and liquid transportation fuels. In this contribution, computational methods at the DFT B3LYP level of theory are employed to understand the efficacy of lanthanide triflate catalysts (Ln(OTf)3, Ln = La, Ce, Sm, Gd, Yb, and Lu) in cleaving etheric C–O bonds. In agreement with experiment, the calculations indicate that the reaction pathway for C–O cleavage occurs via a C–H → O–H proton transfer in concert with weakening of the C–O bond of the coordinated ether substrate to ultimately yield a coordinated alkenol. The activation energy for this process falls as the lanthanide ionic radius decreases, reflecting enhanced metal ion electrophilicity. Details of the reaction mechanism for Yb(OTf)3-catalyzed ring opening are explored in depth, and for 1-methyl-d3-butyl phenyl ether, the computed primary kinetic isotope effect of 2.4 is in excellent agreement with experiment (2.7), confirming that etheric ...
Premenopausal plasma 25-hydroxyvitamin D, mammographic density, and risk of breast cancer

Epidemiologic evidence for an association between plasma 25-hydroxyvitamin D [25(OH)D] and breast cancer is inconsistent. Data are especially limited for premenopausal women and for associations with mammographic density. To test the hypothesis that plasma concentration of 25(OH)D is associated with mammographic density, we conducted a cross-sectional study among 835 premenopausal women in the Nurses’ Health Studies. We measured 25(OH)D in blood samples and used multivariable linear regression to quantify the association of average percent density by quartile of plasma 25(OH)D. In a nested case-control analysis including 493 breast cancer cases, we evaluated risk of breast cancer associated with vitamin D status within tertiles of mammographic density. Women in the top quartile of plasma 25(OH)D levels had an average percent breast density 5.2 percentage points higher than women in the bottom quartile (95 % confidence interval: 1.8, 8.7; P trend <0.01), after adjusting for predictors of 25(OH)D and established breast cancer risk factors. Plasma 25(OH)D concentration was significantly inversely associated with breast cancer risk among women with high mammographic density (P trend < 0.01) but not among women in lower tertiles of mammographic density (P-interaction < 0.01). These results do not support the hypothesis that vitamin D is inversely associated with percent mammographic density in premenopausal women. There was evidence that the association between premenopausal 25(OH)D and breast cancer risk varies by mammographic density, with an inverse association apparent only among women with high mammographic density.
Direct-bandgap compositions of the CSiGeSn group-IV alloy

Theoretical estimates are presented in this paper for the composition-dependent direct bandgap of bulk unstrained CSiGeSn. Interpolation between the corresponding bandgaps of elemental C, Si, Ge and Sn at their Γ, L, Δ, and X conduction band minima showed that each of the binary alloys CSn, SiSn and GeSn had a range of direct-gap compositions. Those ranges were plotted on a quaternary composition chart in order to define the boundaries of CSiGeSn composition space within which the alloy is “truly direct.” With the CSiGeSn cubic lattice parameter in the range of 0.576 nm to 0.649 nm, the predicted direct gaps ranged from 1.50 eV down to −0.41 eV. The boundaries of this space shift towards lower Sn content when bowing of the direct and indirect gaps is taken into account.
A tale of two "forests": random forest machine learning AIDS tropical forest carbon mapping.

Accurate and spatially-explicit maps of tropical forest carbon stocks are needed to implement carbon offset mechanisms such as REDD+ (Reduced Deforestation and Degradation Plus). The Random Forest machine learning algorithm may aid carbon mapping applications using remotely-sensed data. However, Random Forest has never been compared to traditional and potentially more reliable techniques such as regionally stratified sampling and upscaling, and it has rarely been employed with spatial data. Here, we evaluated the performance of Random Forest in upscaling airborne LiDAR (Light Detection and Ranging)-based carbon estimates compared to the stratification approach over a 16-million hectare focal area of the Western Amazon. We considered two runs of Random Forest, both with and without spatial contextual modeling by including—in the latter case—x, and y position directly in the model. In each case, we set aside 8 million hectares (i.e., half of the focal area) for validation; this rigorous test of Random Forest went above and beyond the internal validation normally compiled by the algorithm (i.e., called “out-of-bag”), which proved insufficient for this spatial application. In this heterogeneous region of Northern Peru, the model with spatial context was the best preforming run of Random Forest, and explained 59% of LiDAR-based carbon estimates within the validation area, compared to 37% for stratification or 43% by Random Forest without spatial context. With the 60% improvement in explained variation, RMSE against validation LiDAR samples improved from 33 to 26 Mg C ha−1 when using Random Forest with spatial context. Our results suggest that spatial context should be considered when using Random Forest, and that doing so may result in substantially improved carbon stock modeling for purposes of climate change mitigation.