cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract B009: Amalgamated c-MYC activation and p53 loss drives rapid prostate tumorigenesis and lethal epididymis tumors in Ai-Myc model

c-Myc is one of the most frequently amplified genes in human cancers, including prostate cancer (PCa). It is also frequently overexpressed in PCa as early as prostatic intraepithelial neoplasia (PIN). c-Myc overexpression has been shown to induce pathologic changes of mouse prostate, from mostly normal histology, hyperplasia, mPIN, to invasive prostate tumors. Here we describe an Ai-Myc model designed to ectopically express c-Myc and an enhanced luciferase (Luc2) in any tissue in a Cre-inducible manner. To study PCa, Ai-Myc mice were crossed with PB-Cre4 mice to turn on c-Myc expression in prostate epithelia. Once turned on, the expression of transgenes no longer depends on androgen, which allows studying castration of PCa. These mice developed early onset of mPIN along with enhanced apoptosis; only a small fraction of aged mice developed prostate tumors, indicating that c-Myc alone is not sufficient for effectively driving prostate tumorigenesis. Although mutation or loss of p53 is not common in early PCa, it is strongly correlated to PCa disease stages, metastasis, and castration resistance, and p53 is the most significantly altered gene in metastatic castration-resistant PCa. Therefore, we performed conditional ablation of p53 in the PB-Cre4/Ai-Myc mice to model a significant fraction of advanced PCa and to investigate whether loss of p53 inhibits c-Myc oncogene induced apoptosis for robust prostate tumorigenesis. Indeed, these mice rapidly developed prostate tumors; however, within 3-5 months, all mice also unexpectedly developed lethal epididymis tumors, a rare type of cancer in human. Early castration to fully remove epididymis followed by implantation of testosterone pellets allows these mice to develop advanced prostate tumors with metastasis. In summary, we have developed a novel c-Myc induced PCa model and demonstrated that amalgamated c-Myc activation and p53 loss drives rapid prostate tumorigenesis. Our study also unexpectedly revealed a potent tumorigenesis pathway for cancer of epididymis, a rare and poorly understood type of cancer accounting for at most 0.03% of male cancers. Citation Format: Wei Wang, Yanling Meng, Bingning Dong, Feng Yang. Amalgamated c-MYC activation and p53 loss drives rapid prostate tumorigenesis and lethal epididymis tumors in Ai-Myc model [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr B009.
Management of Heart Failure in the Emergency Department Setting: An Evidence-Based Review of the Literature.

Abstract Background Acute heart failure (AHF) is a common presentation to the emergency department (ED), with the potential to cause significant morbidity and mortality. It is important to tailor treatments to the appropriate type of heart failure. Objectives This review provides an evidence-based summary of the current ED management of acute heart failure. Discussion Heart failure can present along a spectrum, especially in acute exacerbation. Treatment should focus on the underlying disease process, with guidelines focusing primarily on blood pressure and hemodynamic status. Treatment of patients with mild AHF exacerbations often focuses on intravenous diuretics. Patients with AHF with flash pulmonary edema should receive nitroglycerin and noninvasive positive pressure ventilation, with consideration of an angiotensin-converting enzyme inhibitor, while monitoring for hypotension. Patients with hypotensive AHF should receive emergent specialty consultation and an initial fluid bolus of 250–500 mL, followed by initiation of inotropic agents with or without vasopressors. Dobutamine is the inotrope of choice in these patients, with norepinephrine recommended if blood pressure support is needed. If noninvasive positive pressure ventilation is required, providers should monitor closely for acute decompensation. Mechanical circulatory support devices may be considered as a bridge to further therapeutic intervention. High-output heart failure can be managed acutely with vasoconstricting agents, with focus on treating the underlying etiology. Disposition is not always straightforward, and several risk scores may assist in this decision. Conclusion AHF is a condition that requires rapid assessment and management. Understanding the appropriate management strategy can allow for more targeted treatment and improved outcomes.
A Low-Power, Compact 76-81GHz FMCW Transmitter for Automotive Radar in 22nm FDSOI

A fully-integrated low-power and compact FMCW transmitter for automotive radar is presented. It consists of a passive mixer-based frequency multiplier, a push-push frequency doubler, an injection-locked power amplifier and a power amplifier. The input frequency (19-20.25GHz) of the transmitter is multiplied by 4 to produce an output frequency ranging from 76-81GHz. The design has been fabricated using 22nm FDSOI process. The minimum measured output power from 76-81GHz is 10.5dBm to 8dBm. The measured 1MHz offset phase noise is −109dBc/Hz. The total power consumption is 88.5mW and the chip occupied an area of merely 430µm×150µm.
Part-Time Employment of Older Workers in the Service Industry

The social phenomena of the “greying” of America is just beginning to impact the business community and the marketplace. Demographic shifts are influencing employee profiles and personnel resources. The purpose of this study is to survey personnel directors in the service industry regarding attitudes toward and experience with part-time older employees (over 55). People who are responsible for employment decisions in the retailing, food chain, and fast food industries were questioned concerning older employee compatibility with the target market, competence, dependability, flexibility, image, and special needs.
Proximity-CLIP and Expedited Non-Radioactive Library Preparation of Small RNA Footprints for Next-Generation Sequencing

During the course of their life cycle, most RNAs move between several cellular environments where they associate with different RNA binding proteins (RBPs). Reciprocally, a significant portion of RBPs reside in more than a single cellular compartment, where they can interact with discrete RNAs and even exert distinct biological roles. Proximity-CLIP combines proximity biotinylation of proteins with photoactivatable ribonucleoside-enhanced protein-RNA crosslinking to simultaneously profile the proteome, including RBPs and the RBP-bound transcriptome, in any given subcellular compartment. Here we provide a detailed experimental protocol for Proximity-CLIP along with a simplified non-radioactive, small-RNA cDNA library preparation protocol. Published 2020 U.S. Government. Basic Protocol 1: Cell culture, 4SU labeling, proximity biotinylation, and crosslinking Basic Protocol 2: Cell extraction, streptavidin affinity purification, and on-beads trypsinization Basic Protocol 3: RNA footprints cDNA library preparation Support Protocol: Preparation of RNA-seq libraries from intact RNA.
Unit Circle Rectification of the Minimum Variance Distortionless Response Beamformer

The sample matrix inversion (SMI) beamformer implements Capon's minimum variance distortionless (MVDR) beamforming using the sample covariance matrix (SCM). In a snapshot limited environment, the SCM is poorly conditioned resulting in a suboptimal performance from the SMI beamformer. Imposing structural constraints on the SCM estimate to satisfy known theoretical properties of the ensemble MVDR beamformer mitigates the impact of limited snapshots on the SMI beamformer performance. Toeplitz rectification and bounding the norm of weight vector are common approaches for such constraints. This paper proposes the unit circle rectification technique which constrains the SMI beamformer to satisfy a property of the ensemble MVDR beamformer: for narrowband planewave beamforming on a uniform linear array, the zeros of the MVDR weight array polynomial must fall on the unit circle. Numerical simulations show that the resulting unit circle MVDR (UC MVDR) beamformer frequently improves the suppression of both discrete interferers and white background noise compared to the classic SMI beamformer. Moreover, the UC MVDR beamformer is shown to suppress discrete interferers better than the MVDR beamformer diagonally loaded to maximize the signal-to-interference-plus-noise ratio.
Extensive sampling for complete models of individual brains

In designing cognitive neuroscience experiments, resource limitations induce a fundamental trade-off between sampling variation across individual brains and sampling variation across experimental conditions. Here, we argue that extensive sampling of experimental conditions is essential for understanding how human brains process complex stimuli, that a model of how any one brain does this is likely to generalize to most other brains, and that introducing large numbers of subjects into an analysis pool is likely to introduce unnecessary and undesirable variance. Thus, contrary to conventional wisdom, we believe that sampling many individuals provides relatively few benefits and that extensive sampling of a limited number of subjects is more productive for revealing general principles. Furthermore, an emphasis on depth in individual brains is well-suited for capitalizing on the improvements in resolution and signal-to-noise ratio that are being achieved in modern neuroscientific measurement techniques.
Utilizing Sneak Paths for Memristor Test Time Improvement

Memristor technology is becoming an attractive option for memory architectures, in-memory computing, and logic applications due to their non-volatility, high density, and low power operation. Howev...
Trends in frequency of e-cigarette use among cancer patients and survivors in the United States, 2014-2018.

Abstract Introduction Electronic cigarettes (e-cigarettes) have become increasingly popular in the United States, including among cancer survivors; however, the majority of prior studies do not report frequency of active e-cigarette usage. Methods Using data from the National Health Interview Survey (2014–2018), frequency of active e-cigarette usage was estimated among cancer survivors reporting history of e-cigarette usage. Multivariable logistic regression analyses defined adjusted odds of active e-cigarette usage (either every day and some days vs. not at all) by year of survey and baseline demographic characteristics. Results Among 1529 cancer survivors who reported ever using e-cigarettes, 1172 (76.7%) were not active users, while 145 (9.5%) and 212 (13.9%) actively used e-cigarettes every day or some days, respectively. Later year of survey was negatively associated with active e-cigarette usage (p Conclusions The majority of cancer survivors who have ever used e-cigarettes do not appear to be actively using them. Rather, our findings suggest that the reported increasing popularity of e-cigarettes may be driven by a growing absolute proportion of individuals trying e-cigarettes over time. Those who were current or former traditional cigarette smokers were more likely to actively use e-cigarettes. Our findings can help inform current policies on e-cigarettes and contextualize studies on long-term effects of e-cigarettes among survivors of cancer.
Is There a Molecular Basis to Accelerated Aging

* Abbreviations: ELBW — : extremely low birth weight NBW — : normal birth weight In 1989, Barker et al1 proposed that poor maternal nutrition, as evidenced by reductions in birth weight, increased the risk of later-life adverse cardiovascular and metabolic outcomes in the offspring. This hypothesis was based on ecological and cohort data, which indicated that reduced birth weight, intrauterine growth retardation, and preterm birth were associated with increased risks of hypertension, coronary heart disease, and type II diabetes later in life.2 Now known as the Barker hypothesis, the thrifty phenotype hypothesis, the developmental origins of adult health, or the early determinant of health, this hypothesis has been expanded to include adverse events (eg, maternal stress, other maternal illnesses) or exposures (eg, heavy metals, endocrine disruptors, air pollution, psychosocial stress) during pregnancy and early life and numerous later-life outcomes and has spawned a new focus for epidemiology and a new name for what had been done for more than a century: life course epidemiology.3 Since the explication of the Barker hypothesis, numerous investigations have been used to attempt to find its molecular basis. Explanations include reductions in telomere length4 and changes in the epigenetic profile,5 both … Address correspondence to Pam Factor-Litvak, PhD, Department of Epidemiology, Mailman School of Public Health, Columbia University, 722 W 168 St, New York, NY 10032. E-mail: prf1{at}cumc.columbia.edu
Atmospheric-pressure CVD growth of two-dimensional 2H- and 1 T'-MoTe 2 films with high-performance SERS activity.

Two-dimensional (2D) molybdenum ditelluride (MoTe2) is a member of the transition-metal dichalcogenides family, which is an especially promising platform for surface-enhanced Raman scattering (SERS) applications, due to its excellent electronic properties. However, the synthesis of large-area highly crystalline 2D MoTe2with controllable polymorphism is a huge challenge due to the small free energy difference (∼40 meV per unit cell) between semiconducting 2H-MoTe2and semi-metallic 1 T'-MoTe2. Herein, we report an optimized route for the synthesis of 2H- and 1 T'-MoTe2films by atmospheric-pressure chemical vapor deposition. The SERS study of the as-grown MoTe2films was carried out using methylene blue (MB) as a probe molecule. The Raman enhancement factor on 1 T'-MoTe2was found to be three times higher than that on 2H-MoTe2and the 1 T'-MoTe2film is an efficient Raman-enhancing substrate that can be used to detect MB at nanomolar concentrations. Our study also imparts knowledge on the significance of a suitable combination of laser excitation wavelength and molecule-material platform for achieving ultrasensitive SERS-based chemical detection.
The human body burden of polychlorinated biphenyls in serum of residents in an area from Hubei Province

Concentrations of dioxin-like polychlorinated biphenyls (dl-PCBs) and non-dioxin-like PCBs (ndl-PCBs) in 26 serum samples of the residents from Hubei Province were analyzed via high-resolution gas chromatograph tandem high-resolution mass spectrometer (HRGC-HRMS) method. Total concentrations of twelve dl-PCBs (Σdl-PCBs) were in range of 366.30-4 945.77 pg/g fat, with the mean value (2 093.76 pg/g fat), and PCB 118 was the predominant congener. For six ndl-PCBs, total concentrations (Σndl-PCBs) were in range of 2 671.32-20 626.26 pg/g fat (mean 12 505.45 pg/g fat), and PCB 153 was the predominant congener. Mean concentration of Σdl-PCBs were significantly and positively associated with age (rs=0.574, P=0.002). The mean World Health Organization toxicity equivalent (WHO-TEQ) of dl-PCBs (ΣTEQdl-PCBs) were range from 0.07 to 8.69 pg/g fat.
Hydrostannylation of carbon dioxide by a hydridostannylene molybdenum complex.

Reaction of the aryltin(II) hydrides {AriPr4Sn(μ-H)}2 or {AriPr6Sn(μ-H)}2 (AriPr4 = –C6H3-2,6-(C6H3-2,6-iPr2)2, AriPr6 = –C6H3-2,6-(C6H2-2,4,6-iPr3)2) with two equivalents of the molybdenum carbonyl [Mo(CO)5(THF)] afforded the divalent tin hydride transition metal complexes, Mo(CO)5{Sn(AriPr6)H}, (1), or Mo(CO)5{Sn(AriPr4)(THF)H} (2), respectively. Complex 1 effects the facile hydrostannylation of carbon dioxide, to yield Mo(CO)5{Sn(AriPr6)(κ2-O,O′-O2CH)}, (3), which features a bidentate formate ligand coordinating the tin atom. Reaction of 3 with the pinacolborane, HBpin (pin = pinacolato) in benzene regenerated 1 in quantitative yield. All complexes were characterized by X-ray crystallography, as well as UV-visible, IR, and multinuclear NMR spectroscopies. The isolation of 1 and 2 is consistent with the existence of monomeric forms of {AriPr4Sn(μ-H)}2 and {AriPr6Sn(μ-H)}2 in solution. Regeneration of 1 from 3via reaction with pinacolborane as the hydrogen source shows the catalytic potential of 1 in the hydrogenation of CO2.
Purpose of the Study

This book is about planning for the development of builders, leaders and managers of business enterprises for the 21st century. Its underlying premise is that because so many MBA graduates of schools of business and management attain positions of major responsibility in their organizations, the education received by these young men and women has an important impact on the way in which businesses are, and will be, conceived, developed, led and managed.
Determination of the Expressed T cell Repertoire: The Outcome of Competition at the Levels of Antigen Presentation and T cell Receptor Recognition

The first half of the 20th century saw a revelation in our understanding of the exquisite specificity of antibodies, best exemplified in the work by Karl Landsteiner. A single substituent on a hapten could be readily distinguished from a closely related one by an animal’s antiserum. The various antibodies in that antiserum, with their unique perspectives of these cross-reactive haptens/determinants, combined to provide an unmistakable portrait of each region of the antigen. Of course, some antibodies overlapped with others so that, in a sense, a continuum of antibody footprints could be drawn covering the structure.
Clinical aspects of cholinergic pharmacology.

Publisher Summary Clinical strategies attempting to stabilize central cholinergic dysfunctions, whether disease oriented or induced externally, have generally been only moderately successful. This could be attributed in part to the ubiquitous nature of the cholinergic network in the brain, as well as in the periphery and complicated by the diversity of pathways in the central nervous system that are controlled by, or involve cholinergic innervation. Since the series of international cholinergic conferences, of which this is the eighth, have served as a “finger on the pulse” of cholinergic development over the past two decades, it was of interest to survey the proceedings of these conferences, in order to identify, which, if any, “clinical cholinergic therapies” have been applied from the time of the first cholinergic conference in Skokloster, in 1970. In this category, this chapter includes any clinical pharmacological interventions employing compounds that either act as precursors for the synthesis of acetylcholine, agents that directly affect the enzymes involved in the synthesis or destruction of acetylcholine or agents that interact with cholinergic receptors, whether muscarinic or nicotinic, either at pre- or post-synaptic sites.
Dynamic Task Performance, Cohesion, and Communications in Human Groups

In the study of the behavior of human groups, it has been observed that there is a strong interaction between the cohesiveness of the group, its performance when the group has to solve a task, and the patterns of communication between the members of the group. Developing mathematical and computational tools for the analysis and design of task-solving groups that are not only cohesive but also perform well is of importance in social sciences, organizational management, and engineering. In this paper, we model a human group as a dynamical system whose behavior is driven by a task optimization process and the interaction between subsystems that represent the members of the group interconnected according to a given communication network. These interactions are described as attractions and repulsions among members. We show that the dynamics characterized by the proposed mathematical model are qualitatively consistent with those observed in real-human groups, where the key aspect is that the attraction patterns in the group and the commitment to solve the task are not static but change over time. Through a theoretical analysis of the system we provide conditions on the parameters that allow the group to have cohesive behaviors, and Monte Carlo simulations are used to study group dynamics for different sets of parameters, communication topologies, and tasks to solve.
Sensitivity of Three Selected Bacterial Species to Ozone

THE MINIMAL LETHAL CONCENTRATION OF OZONE IN WATER WAS DETERMINED FOR THREE BACTERIAL SPECIES: Escherichia coli, Bacillus cereus, and Bacillus megaterium. A contact period of 5 min was selected. The lethal threshold concentration for the cells of B. cereus was 0.12 mg/liter while that for E. coli and B. megaterium was 0.19 mg/liter. Low concentrations of ozone were ineffective when organic matter was present to interfere with the action of ozone on the bacterial cells. Also determined during the study was the sensitivity of spores of B. cereus and B. megaterium to ozone in water. The threshold concentration required to kill the spores of both species was 2.29 mg/liter. The cells and spores of these organisms exhibited the "all-or-none" die-away phenomenon normally associated with ozone treatment.
Globalizing the Rule of Law: Some Thoughts at and on the Periphery

In the wake of the unparalleled economic and political success of the West, rendered in stark relief by the fall of the Berlin wall a decade ago, a triad of concepts has been deployed both to explain the West's ascendancy, and as a prescription for the laggards of the emerging (or "transitional") and underdeveloped countries of the former communist and Third World societies. "Democracy," the "free market," and the "rule of law" are advanced as a trinity that underpin liberal capitalism,1 and without which developing and transitional societies will continue to languish in the shadows of misery. These claims are then presented within what is surely the Zeitgeist of the decade-"globalization." We live, it is frequently asserted, in a "global village." By implication and frequent prescription, the "international community" is (or must be) bound by uniform and universally shared rules, practices, and institutions. Taken together, these four pillars of contemporary "liberal" hegemonic ideology-democracy, free markets, rule of law, and globalization-smilingly explain with equanimity and logic why it is in the interest of the rest of the world to be like North America and Western Europe. Tempting as it is either to accept or reject these claims as platitudes, or to insist on their validation through rigorous empirical data, a third possibility is to recognize that, like most social institutions (and the ideas that underpin them), the truth (or poverty) of the claims (and therefore their ultimate utility, if any), lie less in subjecting them to such classic rational proofs, and more in
Neonatal Deafferentation Does Not Alter Membrane Properties of Trigeminal Nucleus Principalis Neurons

In the brain stem trigeminal complex of rats and mice, presynaptic afferent arbors and postsynaptic target cells form discrete modules (“barrelettes”), the arrangement of which duplicates the patterned distribution of whiskers and sinus hairs on the ipsilateral snout. Within the barrelette region of the nucleus principalis of the trigeminal nerve (PrV), neurons participating in barrelettes and those with dendritic spans covering multiple barrelettes (interbarrelette neurons) can be identified by their morphological and electrophysiological characteristics as early as postnatal day 1. Barrelette cells have focal dendritic processes, are characterized by a transient K+ conductance (I A), whereas interbarrelette cells with larger soma and extensive dendritic fields characteristically exhibit low-threshold T-type Ca2+ spikes (LTS). In this study, we surveyed membrane properties of barrelette and interbarrelette neurons during and after consolidation of barrelettes in the PrV and effects of peripheral deaffere...
Optimising design parameters of continuous mining transport systems using discrete event simulation

The ground articulating pipeline (GAP) system was developed to transport oil sand using a continuous transport system. This paper proposes a simulation-based optimisation approach to improve the efficiency of oil sand continuous transport systems at the operational level. Based on the analysis of shovel capacity, the authors recommend that this GAP transfer system should operate with a 70-ton capacity shovel. They also recommend that a surge hopper should be introduced on the mobile slurry system to maximise productivity of the GAP system. This simulation approach can be applied to crushers and conveyor belt systems.
Recent Publications in Sociolinguistics

Book reviewed in this article: Sociolinguistics and Second Language Acquisition Dennis Preston. Dennis Preston. Perspectives: Sociolinguistics and TESOL Nessa Wolfson. Cambridge: Newbury House, 1989.
Integrating technologies for visual resource management

The visual environment is an important resource requiring a competent, effective management system. Such a system requires defining the resource, inventorying it and its predictors, building predictive models which help asses impacts, integrating all this in a usable format, and providing a mechanism for the presentation of results to decision-makers and the public. Psychophysical methods, GIS based modeling, video-imaging technology, and expert systems are technologies which provide the means to accomplish these tasks. Examples show the potential of each technology. Integration of these separate technologies permits the construction of still more effective management systems.
Murine sarcoma virus-induced brain tumors. Concurrent measurements of blood flow and transcapillary transport.

Intracerebral inoculation of Murine Sarcoma Virus (MSV) into rats induces highly vascular brain tumors. Blood flow, F, and a unidirectional blood-to-tissue transfer constant, K, were measured concurrently in 16 separate brain tumors in 13 rats. Regional measurements of F and K were obtained using double-label quantitative autoradiography with 131I-iodoantipyrine, 14C-alpha aminoisobutyric acid, and computerized microdensitometry with image analysis. Regional tissue extraction fractions (E) were calculated for different brain and tumor regions. The following observations were made: (1) intracerebral inoculation of MSV in rats of different ages produced a single histologic tumor type (angiosarcoma), although tumor yield decreased and latency increased when older rats were inoculated; (2) whole tumor blood flow values averaged 63.9 ± 20.9 (SD) ml hg−1 min−1, less than F of tumor-free gray matter; (3) the mean value of the transfer constant was 1.19 ± 0.84 ml hg−1 min−1, 5 times the value in contralateral tumor-free brain; (4) moderate regional variation of F and K values were observed within each tumor, with increased K values extending into the regions of brain around tumor; (5) mean extraction fractions (E) of AIB for whole tumor were low (range = 0.0021 to 0.08), with a distinct and decreasing gradient from tumor center to BAT; (6) there was poor correlation between F, K and E values, and tumor histology, including regions that microscopically appeared highly vascular; (7) in most regions of the MSV-induced brain tumors, capillary permeability and/ or surface area seem to be determinant in blood-to-tissue transport processes.
Dermatologic manifestations in HIV-infected patients: a primary care perspective.

Objective To document the prevalence of dermatologic manifestations in patients infected with the human immunodeficiency virus (HIV) on presentation to primary medical care. Design Prospective consecutive case series evaluated between June and November 1995. Setting The HIV intake clinic at an urban hospital. Subjects and Methods Ninety-five individuals initiating HIV-related primary care. Results Dermatologic manifestations were found in 82 patients (86%). The most common conditions were dermatophytosis in 32 patients (34%), oral hairy leukoplakia in 22 (23%), and folliculitis in 18 (19%). Well described HIV-associated dermatologic manifestations such as Kaposi sarcoma, herpes zoster, and psoriasis were uncommon. Conclusion The high prevalence of treatable skin disorders found in HIV-infected patients underscores the importance of careful and complete skin examination as a fundamental aspect of the initial clinical evaluation in this population.
Degradation of Toxaphene by Zero-Valent Iron and Bimetallic Substrates

The pesticide, toxaphene, is a major environmental concern and has been reported to be harmful, especially via skin contact, ingestion, or inhalation. Although now banned, it persists in nature. The results of this research showed that toxaphene in an aqueous solution was degraded by dechlorination when contacted with Fe0 and bimetallic substrates. This degradation displayed a power-law relationship with a decrease of toxaphene concentration over time. Toxaphene contacted with Fe0 produced a degradation rate value, − kTox [ln (h) ]−1 , of 0.088 for a solution-to-mass ratio of 4:1 and 0.113 for a 2:1 ratio. Doubling the initial concentration of toxaphene for a volume-to-mass ratio of 4:1 decreased the degradation rate and resulted in a − kTox value of 0.061. Bimetallic substrates including nickel-plated Fe0 and copper-plated Fe0 had degradation values of 0.219 and 0.245, respectively. A chloride mass balance indicated that nearly all of the toxaphene in the solution had been dechlorinated; as the chloride ...
Snowbird II: Global catastrophes: Comment: Meteorite impact, mass extinction and Deccan volcanism

There have been numerous articles in Eos and elsewhere recently that discuss the cause of the mass extinctions at the Cretaceous-Tertiary (K-T) boundary. Clark Chapman's interesting article on the Snowbird II meeting (“Snowbird II: Global Catastrophes,” Eos, April 4, p. 217) is one of the latest. I suppose that few geoscientists would quarrel with his principal conclusion that an association has now been established between the extinctions and the impact of large meteorites, although many paleontologists remain troubled by the inability of a single extraterrestrial impact to account for the complexities of the longdrawn-out extinctions of the various species. My main concern, as an igneous penologist, is the omission by Chapman of any significant reference to the Deccan basalt eruptions, the most frequently suggested alternative cause of the climatic changes that produced the extinctions [Officer and Drake, 1985]. This is now known to have been an extraordinary volcanic event, both in its rate of eruption and in its total volume. Furthermore, the eruptions occurred, as closely as radiometric techniques can define, exactly at the K-T boundary. Barring an unlikely coincidence, these eruptions, unique in the last 100 m.y., must surely be related to the equally exceptional worldwide extinctions. This suggestion may be seen as an unwelcome complication to an otherwise satisfactory explanation for the extinctions. Yet, if we accept Chapman's conclusion that the extinctions are probably the result of meteorite impact, then we should also accept, at least as a working hypothesis, that meteorite impact, continental flood basalt eruptions, and the extinctions are interconnected [Alt et al., 1988; Basu et al., 1988].
Selective activation of PPARγ in breast, colon, and lung cancer cell lines

Abstract Peroxisome proliferator-activated receptor gamma (PPARγ) plays a critical albeit poorly defined role in the development and progression of several cancer types including those of the breast, colon, and lung. A PPAR response element (PPRE) reporter assay was utilized to evaluate the selective transactivation of PPARγ in 10 different cell lines including normal mammary epithelial, breast, lung, and colon cancer cells. Cells were treated with one of four compounds including rosglitizone (Ros), ciglitizone (Cig), 15-deoxy-Δ12,14-prostaglandin J2 (PGJ2), or GW 9662 (GW). We observed differences in transactivation between cell lines from different tissue origin, across cell lines from a single tissue type, and selective modulation of PPARγ within a single cell line by different ligands. Interestingly, GW, a PPARγ antagonist in adipocytes, enhanced PPRE reporter activation in normal mammary epithelial cells while it had virtually no effect in any of the cancer cell lines tested. Within each cancer type, individual cell lines were found to respond differently to distinct PPARγ ligands. For instance, Ros, Cig, and PGJ2 were all potent agonist of PPARγ transactivation in lung adenocarcinoma cell lines while these same ligands had no effect in squamous cell or large cell carcinomas of the lung. Message levels of PPARγ and retinoid X receptor alpha (RXRα) in the individual cell lines were quantitated by real time-polymerase chain reaction (RT-PCR). The ratio of PPARγ to RXRα was predictive of how cells responded to co-treatment of Ros and 9-cis-retinoic acid, an RXRα agonist, in two out of three cell lines tested. These data indicate that PPARγ can be selectively modulated and suggests that it may be used as a therapeutic target for individual tumors.
Homocysteine Is Not So Paradoxical

To the Editor: Rodionov and Lentz1 summarized the homocysteine paradox. Hyperhomocysteinemia disrupts vascular structure and function in animals and predicts risk of “coronary events, stroke, venous thromboembolism, and death,” yet clinical benefit in intervention trials remains unproved. They offer several plausible explanations. Trials usually involve dietary supplementation with folate and vitamins B-6 and B-12. It also seems plausible that results would have been better if the intervention trials included copper. High homocysteine concentrations lead to increased homocysteine thiolactone,2 an …
Renal insufficiency and end-stage renal disease in the heart transplant population.

Abstract Background Renal insufficiency and end-stage renal disease (ESRD) are important problems in the cardiac transplant population, and are associated with significant morbidity, mortality and financial cost. We undertook this study to define pre-operative or early post-operative predictors of subsequent renal insufficiency and ESRD. Methods We studied 370 patients at Brigham and Women's Hospital who received heart transplants between 1984 and 1999, with up to 10-year follow-up. We evaluated 2 time-dependent primary outcomes: early reduction in GFR, and development of ESRD at any timepoint. Cox proportional hazards modeling was used in both univariate and multivariate analyses. Results The mean estimated glomerular filtration rate (GFR) fell 24% within the first post-transplant year, and remained stable thereafter. By actuarial analysis, 23% of patients developed a 50% reduction in GFR by the third year, and 20% developed ESRD by the tenth year of follow-up. In Cox multivariate analysis, significant predictors of post-transplant ESRD included: GFR p = 0.024); high mean cyclosporine trough in the first 6 months (HR 5.10, p = 0.0059); and presence of diabetes (HR 3.53, p = 0.021). Conclusions about renal insufficiency outcome were limited by difficulties with accurate estimation of GFR and with definition of renal insufficiency. Conclusions The results of this study underscore the magnitude of the problem of renal insufficiency and ESRD in the heart transplant population. In addition, these data suggest that patients at high risk for these outcomes can be identified early, even pre-operatively, to guide post-operative management.
From Brown to Green? Assessing Social Vulnerability to Environmental Gentrification in New York City

Although urban sustainability programs frequently include measures that focus on the environmental and economic components of sustainability, the social dimension of sustainability remains underrepresented. An analytical vulnerability approach from global change vulnerability research provides one way to evaluate the distributional impacts and procedural aspects of sustainability initiatives. I apply the vulnerability approach to a study of one contemporary sustainability initiative in New York City, brownfield redevelopment, and identify populations who are vulnerable to the negative impacts of the redevelopment process: elderly residents, renters, and residents receiving government assistance. The results of the case study suggest that the vulnerability approach provides a way to develop indicators of social sustainability for inclusion in existing urban sustainability indicator projects.
Commentary on Herbert Kelman's Contribution to Interactive Problem Solving

It is an honor and a challenge to provide a commentary on Herbert Kelman's work on interactive problem solving (IPS), which presents a complex and integrated tapestry of theory, research, and practice devoted to the resolution of violent intergroup conflict, with special attention to the Israeli–Palestinian tragedy. In his tapestry, Herb has created a systematic and comprehensive description of the major components of IPS and its connections to the broader flow of international conflict management. Through four decades of thoughtful analysis and practice, Herb has articulated and elaborated the social-psychological rationale and the social technology of the problem-solving workshop (PSW) as the primary vehicle for IPS. The long term application of IPS to the Israeli–Palestinian conflict demonstrates the relevance and utility of the method, and will stand as a lasting contribution to the eventual resolution of that costly and tragic interaction.
Vasopressin administration prevents functional recovery of the vasopressinergic neurosecretory system following neurohypophysectomy

The rodent hypothalamic neurosecretory system normally exhibits remarkable functional and structural plasticity following injury. However, the present study describes a newly observed phenomenon in which neurohypophysectomized animals receiving chronically administered exogenous vasopressin during the post-lesion period (a treatment which insures maximal renal antidiuresis over this time frame) lose all capacity for recovery of antidiuretic function. Functional deficits are accompanied by a severe reduction in the number of neurons exhibiting immunohistochemical staining for arginine vasopressin. These data indicate that the presence of neurological stimulation signaling vasopressin release may play an important role in promoting neural regeneration of the vasopressinergic component of the neurosecretory system.
Effects of Terpenes and Phenolic and Flavonoid Glycosides from Douglas Fir on Western Spruce Budworm Larval Growth, Pupal Weight, and Adult Weight

Monoterpenes, sesquiterpenes, and phenolic and flavonoid glycosides typical of the current year's foliage of Douglas fir (Pseudotsuga menziesii) were bioassayed using agar diets to determine the effect of these compounds on natural and colony populations of western spruce budworm (Choristoneura occidentalis). Several terpenes adversely affected budworm larval growth, supporting previous field and laboratory studies. However, larvae collected from a population in southeastern Idaho were significantly more tolerant of the monoterpenes than those from a Montana population. For the Montana population, agar diet studies showed that camphene, myrcene, terpinolene, bornyl acetate, and tricyclene adversely affected larval growth rate and pupal weight. For the Idaho population, agar diet studies showed that only terpinolene and bornyl acetate adversely affected larval growth and pupal weights. For both populations bornyl acetate was the most toxic, and this compound in addition to other monoterpenes represent defensive mechanisms in the current year's growth of Douglas fir. Sesquiterpene and phenolic-flavonoid glycoside fractions extracted from Douglas fir current year's growth also were bioassayed using agar diets. The sesquiterpene fraction showed a significant negative effect on budworm larval growth, but phenolics and flavonoid glycosides had no effect. Sesquiterpenes, in combination with tricyclene, camphene, myrcene, limonene, terpinolene, and the acetate fraction appear to represent an effective mixture of defensive compounds against the budworm.
Determination of optical constants from extinction measurements

Traditional methods of determining the optical constants of particulate materials by means of transmission, absorption, and reflectance measurements are known to be inherently inaccurate. The use of the Lorenz–Mie formalism to derive the optical constants from extinction data overcomes the problems associated with the traditional methods; but, as currently practiced, this method has severe limitations. In this paper we report an entirely new approach to determining the optical constants of aerosols from extinction data. This is an iterative method that uses the Lorenz–Mie formalism in conjunction with the Kramers–Kronig dispersion relations in order to derive the optical constants of the aerosol material. The theory of the method is developed in detail and is applied successfully to find the optical constants of an o-phosphoric-acid aerosol in the 7–14-μm infrared. The numerical procedure is shown to introduce an error of less than 1% in the determination of the o-phosphoric-acid optical constants. Limits on n, k and the particle size distribution for which the method is valid are indicated.
XI. The application of least squares

Abstact The principle of least squares is applied to the general problem of finding the most probable values of observed quantities and of parameters that are related by equations of various sorts. The entire derivation is based on the statement of the principle that the weighted sum of the squares of the residuals is to be minimized with respect to the most probable values of the observed quantities and of any parameters that enter relations between these quantities. These relations will vary in form and number from one type of problem to another. The general solution takes the form of symmetrical equations, and the term “general normal equations” is suggested for them. For a specific type of problem these reduce to a form characteristic of that type.
Formulation of rigid body impact problems using generalized coefficients

Abstract The equations of motion of a rigid body expressed in terms of impulse and momentum are linear. When applied to rigid body collisions, it is known that the equations of motion are insufficient to provide a solution of the classical impact problem; an additional equation is needed for each unknown impulse component. Using a set of coefficients, a problem formulation is presented that extends Newton's approach for collinear impacts of particles to three-dimensional impact problems. Being linear and algebraic these equations can be solved, providing a set of solution equations in terms of the physical system parameters, initial conditions and the coefficients. A unique feature of these equations is that they are independent of the contact process(es) and apply to all collisions meeting the rigid body assumptions, whether energy is or is not conserved (contact processes may involve the release of stored energy). Certain solution behavior, including the energy change can be found by treating the coefficients as parameters. By imposing work-energy and/or kinematic constraints, coefficients can be bounded to insure realistic solutions. Coefficients are defined for couple-impulses so the approach is not limited to point contact. Examples are given of the collision of a sphere against a massive barrier (surface). In one, the sphere has an initial cross spin (about its roll-spin axis) and the tangential process is Coulomb friction. Another, including experimental data, is for microspheres ( ∼ 1–100 μm diameter), where the dynamic contact processes are not fully understood.
Nonstationary state of superconductors: Application to nonequilibrium tunneling detectors

The nonequilibrium state of a superconductor caused by an external source (e.g., x or \ensuremath{\gamma} rays) and its relaxation dynamics are studied. Microscopic theory allows one to evaluate the distribution functions and characteristic time scales for all cascade stages. The appearance of quasiparticles in the nonequilibrium state leads to an additional contribution to the tunneling current. The time dependence of the current flowing through a superconducting tunneling detector is evaluated.
Cost modeling of N-version fault-tolerant software systems for large N

A cost model determines system costs for fault-tolerant software systems. The model finds the optimal number of program versions to achieve minimum system cost of the fault-tolerant software techniques: N-version programming, recovery block, and consensus recovery block. In this case, all versions, the voter, and the acceptance test have the same reliability. When the parameters for the versions, acceptance test, and voter in the cost function are all equal, the cost of a 3-version system is always optimal, Cost(CRB)/spl Lt/Cost(RB)/spl Lt/Cost(NVP) for each target reliability differing by as much as two orders of magnitude in some cases. The cost functions were increasing functions of N. When the parameters are not equal, optimality occurred for other values of N. This was especially the case when the cost exponent for version-1 was larger than the exponents for the other versions and the acceptance test or voter. As the values of the cost exponents for the version reliabilities become larger, a smaller difference was required between the version-1 exponent and the others to produce alternate optima.
Forcing and Organization of Convective Systems

Perhaps as in no other area of meteorology, radar has proven to be the key tool in modern detection and forecasting, as well as in identifying and understanding the physics, of convective storms and convective systems. From its initial deployment as a research tool following the second World War [see the excellent review of the history of radar meteorology in chapter 1 of the AMS monograph Radar in Meteorology, edited by Dave Atlas (Fletcher 1990)], radar has played a fundamental role in increasing our understanding of the forces that initiate and organize severe storms and larger convective systems that are composed of a conglomeration of convective storm cells. Early radar observations were primarily descriptive and showed the tremendous variety of types and sizes of precipitating moist convection (see reviews by Browning 1990; Parsons et al. 1990; Ray 1990; Carbone et al. 1990b; Smull 1995). Examples of types include single convective storms, longer-lived multicellular storms, fast-moving squall lines, slower-moving linear and nonlinear convective systems, and long-lived supercell storms. Although this review emphasizes the role played by radar in observational studies of convective storms and systems, the ever-increasing use of numerical models in explaining the dynamics of precipitating convective systems has resulted in the inclusion of many of those studies. Moreover, we believe numerical models will play an increasing role in extending our understanding of these phenomena by providing information on variables and in areas that are unobserved by radar and other instruments. Likewise, the accuracy of simulations that involve unavoidable parameterization of unresolved or poorly understood physics must be verified against data from the same observing systems.
Structured inverse eigenvalue problems

An inverse eigenvalue problem concerns the reconstruction of a structured matrix from prescribed spectral data. Such an inverse problem arises in many applications where parameters of a certain physical system are to be determined from the knowledge or expectation of its dynamical behaviour. Spectral information is entailed because the dynamical behaviour is often governed by the underlying natural frequencies and normal modes. Structural stipulation is designated because the physical system is often subject to some feasibility constraints. The spectral data involved may consist of complete or only partial information on eigenvalues or eigenvectors. The structure embodied by the matrices can take many forms. The objective of an inverse eigenvalue problem is to construct a matrix that maintains both the specific structure as well as the given spectral property. In this expository paper the emphasis is to provide an overview of the vast scope of this intriguing problem, treating some of its many applications, its mathematical properties, and a variety of numerical techniques.