cssi/SciSciGPT-SciSciNet huggingface dataset:
Simulating forest cover change in the northeastern U.S.: decreasing forest area and increasing fragmentation

Understanding how the Northern Forest landscape has changed and is likely to change, both in terms of forest extent and forest configuration, has important implications for management. We examined historical changes in forest pattern and extent to: (1) characterize recent forest cover change and potential drivers of that change, (2) identify areas vulnerable to future forest loss, (3) assess the impact of such loss on forest fragmentation, and (4) examine correlations between projected forest loss and socioeconomic variables to help inform future planning. We developed a cellular automata model to simulate changes in forest land cover in the Northern Forest region from 2015 to 2075. The model was parameterized from observed historical trends (1985 to 2015) and correlating spatial variables using Bayesian Weights of Evidence. Using our model outputs, we identified areas most vulnerable to change, and impacts of these changes on forest fragmentation. Though we find an overall trend of decreasing forest area across the region, rates of change vary spatially and temporally, with an overall increase in forest cover between 2000 and 2015. Areas most attractive for development (e.g. high population density, low slope and elevation) were most likely to experience deforestation. Forest fragmentation increased during observed and simulated time steps, even during an observed period of net forest regeneration. Forest loss and fragmentation due to development represent a formidable threat to the Northern Forest. Historical trends indicate that simply increasing forest extent is not sufficient to restore forest connectivity in the region.
Identification of preferentially exposed crystal facets by X-ray diffraction

Crystals with exposed facets are popular materials in many catalytic applications due to their high reactivity. Facet identification is often conducted by transmission electron microscopy (TEM). In this work, we analyze the effects of doping, vacancy creation, anisotropic broadening, and preferred orientation on the intensity of X-ray diffraction (XRD) peaks by using tetragonal bismuth oxyhalides (BiOX, X = Cl, Br, and I) as examples. The differences in these effects were successfully used to identify the preferentially exposed (001) facets of BiOX nanoplates synthesized by a polymer-assisted precipitation method. In comparison to TEM, the XRD analysis is not only cheaper and easier to perform, but also it gives results representative for the sample. This work aims to provide further justification for the use of XRD as a powerful and handy characterization technique in the field of crystal facet engineering.
Metabolic profiling of synthetic cannabinoid 5F-ADB and identification of metabolites in authentic human blood samples via human liver microsome incubation and ultra-high-performance liquid chromatography/high-resolution mass spectrometry.

Rationale Indazole carboxamide synthetic cannabinoids, a prevalent class of recreational drugs, are a major clinical, forensic and public health challenge. One such compound, 5F-ADB, has been implicated in fatalities worldwide. Understanding its metabolism and distribution facilitates the development of laboratory assays to substantiate its consumption. Synthetic cannabinoid metabolites have been extensively studied in urine; studies identifying metabolites in blood are limited and no data on the metabolic stability (half-life, clearance and extraction ratio) of 5F-ADB have been published prior to this report. Methods The in vitro metabolism of 5F-ADB was elucidated via incubation with human liver microsomes for 2 h at 37°C. Samples were collected at multiple time points to determine its metabolic stability. Upon identification of metabolites, authentic forensic human blood samples underwent liquid-liquid extraction and were screened for metabolites. Extracts were analyzed via ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOFMS) operated in positive electrospray ionization mode. Results Seven metabolites were identified including oxidative defluorination (M1); carboxypentyl (M2); monohydroxylation of the fluoropentyl chain (M3.1/M3.2) and indazole ring system (M4); ester hydrolysis (M5); and ester hydrolysis with oxidative defluorination (M6). The half-life (3.1 min), intrinsic clearance (256.2 mL min-1 kg-1 ), hepatic clearance (18.6 mL min-1 kg-1 ) and extraction ratio (0.93) were determined for the first time. In blood, M1 was present in each sample as the most abundant substance; two samples contained M5; one contained 5F-ADB, M1 and M5. Conclusions 5F-ADB is rapidly metabolized in HLM. 5F-ADB, M1 and M5 are pharmacologically active at the cannabinoid receptors (CB1 /CB2 ) and M1 and M5 may contribute to a user's impairment profile. The results demonstrate that it is imperative that synthetic cannabinoid assays screen for pharmacologically active metabolites, especially for drugs with short half-lives. The authors propose that M1 and M5 are appropriate markers to include in laboratory blood tests screening for 5F-ADB.
A survey of multiscale modeling: Foundations, historical milestones, current status, and future prospects

Research problems in the domains of physical, engineering, biological sciences often span multiple time and length scales, owing to the complexity of information transfer underlying mechanisms. Multiscale modeling (MSM) and high-performance computing (HPC) have emerged as indispensable tools for tackling such complex problems. We review the foundations, historical developments, and current paradigms in MSM. A paradigm shift in MSM implementations is being fueled by the rapid advances and emerging paradigms in HPC at the dawn of exascale computing. Moreover, amidst the explosion of data science, engineering, and medicine, machine learning (ML) integrated with MSM is poised to enhance the capabilities of standard MSM approaches significantly, particularly in the face of increasing problem complexity. The potential to blend MSM, HPC, and ML presents opportunities for unbound innovation and promises to represent the future of MSM and explainable ML that will likely define the fields in the 21st century.
The Impact of COVID-19 on the Academic Plans and Career Intentions of Future STEM Professionals

Future science, technology, engineering, and mathematics (STEM) professionals are a key part of dealing with disasters like that of the coronavirus disease of 2019, but the pandemic may result in a gap in individuals joining the STEM workforce. In the present work, we offer a picture of our students’ identity as scientists and intentions to pursue a science career from before and after the transition to online instruction that occurred as part of the initial phase of the pandemic response. Additionally, we asked our students to describe the ways this transition has affected their academic plans to provide an in-depth look into their intentions. Data collection involved the administration of a questionnaire to first-year general chemistry laboratory students at the beginning and end of the spring 2020 semester (January–May). The data indicate that there was no significant change to our students’ identities and intention to pursue a career in science during spring 2020, and our students written responses indicate that they are making short-term academic changes that could affect their graduation date but do not suggest any serious changes to career plans. We conclude that the initial transition to online instruction due to the pandemic had a minimal effect on our students’ career intentions, and future work can use this data to better understand the long-term effects of the pandemic on STEM students.
Construction of a class of forward performance processes in stochastic factor models, and an extension of Widder’s theorem

We consider the problem of optimal portfolio selection under forward investment performance criteria in an incomplete market. Given multiple traded assets, the prices of which depend on multiple observable stochastic factors, we construct a large class of forward performance processes, as well as the corresponding optimal portfolios, with power-utility initial data and for stock–factor correlation matrices with eigenvalue equality (EVE) structure, which we introduce here. This is done by solving the associated nonlinear parabolic partial differential equations (PDEs) posed in the “wrong” time direction. Along the way, we establish on domains an explicit form of the generalised Widder theorem of Nadtochiy and Tehranchi (Math. Finance 27:438–470, 2015, Theorem 3.12) and rely for that on the Laplace inversion in time of the solutions to suitable linear parabolic PDEs posed in the “right” time direction.
SPITZER SPACE TELESCOPE MID-IR LIGHT CURVES OF NEPTUNE

We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17 hr duration light curves of Neptune at 3.6 and 4.5 μm. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 μm and 0.6 mag at 4.5 μm. We have also extracted sparsely sampled 18 hr light curves of Neptune at W1 (3.4 μm) and W2 (4.6 μm) from the Wide-feld Infrared Survey Explorer (WISE)/NEOWISE archive at six epochs in 2010–2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler/K2 in the visible (amplitude ~0.02 mag) or at 845 nm with the Hubble Space Telescope (HST) in 2015 and at 763 nm in 2016 (amplitude ~0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune's atmosphere than for K2. Methane gas is the dominant opacity source in Neptune's atmosphere, and methane absorption bands are present in the HST 763 and 845 nm, WISE W1, and Spitzer 3.6 μm filters.
Induction of apoptosis in renal cell carcinoma by combination of maitake mushroom extract (PDF) and vitamin C.

2680 Introduction and Objective: A bioactive extract (PDF) obtained from maitake mushroom (Grifola frondosa) has been demonstrated to have anticancer and immunostimulatory activity. Such bioactivity has also been shown to be synergistically activated by vitamin C (V.C). Although several conventional therapeutic options for renal cell carcinoma (RCC) are currently available, the unsatisfactory outcomes compellingly require for establishing a more effective treatment modality. Accordingly, we examined the combined effects of PDF and V.C on the growth of RCC in vitro as a possible complementary and alternative approach. Methods: The standardized form of mushroom extract, PDF, was obtained commercially. Human RCC, ACHN cell line, was employed and exposed to various concentrations of PDF or in combination with V.C, and cell viability/growth was assessed at specified times. To explore the growth inhibitory mechanism, cell cycle analysis and Western blot analysis on several apoptotic parameters were performed. Results: A dose-dependent study showed that PDF was capable of inducing a ~45% and ~70% growth reduction at 700 and 1000 μg/ml, respectively. When the lower, ineffective concentrations of PDF were combined with V.C (200 μM), ~90% cell death was attained with the combination of 300 µg/ml PDF and V.C. Yet, a given concentration (200 µM) of V.C itself had no effects. Cell cycle analysis revealed that compared to controls, there was an 88% decrease in the S phase cell population with a concomitant 80% increase in the G1 cells following PDF/V.C treatment. Western blots further revealed that PDF/V.C-induced cell death was associated with a down-regulation of anti-apoptotic bcl-2, an up-regulation of pro-apoptotic Bax, and degradation of poly-(ADP-ribose)-polymerase (PARP). Conclusions: The present study demonstrates that PDF has antiproliferative and cytotoxic effects on renal carcinoma ACHN cells in vitro. Although the higher concentrations (>1000 µg/ml) of PDF alone are required to be significantly effective, the lower concentration (300 μg/ml) of PDF can be synergistically potentiated with V.C (200 μM), becoming extremely cytotoxic to these cancer cells (~90% cell death). Such a cytotoxic mechanism is associated with a G1 cell cycle arrest (blocking the G1-S phase transition) and the modulation of critical apoptotic regulators (bcl-2, Bax, and PARP), leading ultimately to apoptosis. Thus, PDF is a potential apoptosis-inducing agent that may have implications in a safer, more effective alternative therapeutic modality for RCC.
Opportunities to Reduce Young Adult College Students' COVID-19-Related Risk Behaviors: Insights From a National, Longitudinal Cohort.

Abstract Purpose To study how young adult college students are managing their health behaviors and risks related to spreading COVID-19. Methods We created a national cohort of full-time college students in late April 2020 (n = 707), and conducted a follow-up survey with participants in July 2020 (n = 543). Participants reported COVID-19-related health risk behaviors and COVID-19 symptoms, and also responded to an open-ended prompt about how the COVID-19 pandemic has affected their lives. Quantitative data were analyzed in Stata and we conducted content analysis to identify themes in the qualitative data. Results For most health protective behaviors (e.g., frequent handwashing, social distancing), participants were less compliant in summer 2020 than spring 2020, with the exception of face mask use, which increased. In each month of the first half of 2020, only approximately half of participants with any symptoms that could indicate COVID-19 stayed home exclusively while symptomatic (there was no meaningful change from pre-pandemic or over the course of the pandemic). In qualitative data, the participants who had gone to bars or clubs at least twice within a 4-week period this summer reported being bored and/or isolated, stressed, and/or taking pandemic safety measures seriously. Conclusions These findings suggest multiple areas for intervention, including harm reduction and risk management education approaches for the students who are going to bars and clubs, and creating policies and programs to better incentivize young people with symptoms to stay home exclusively while symptomatic.
Steroids, Aromatase Inhibitors, and Other Drugs Associated with Osteoporosis

Several classes of medications may accelerate bone loss, thereby increasing the risk of low-trauma fractures in older or younger patients with normal bone density, osteopenia, or osteoporosis. Clinicians should be aware of these possible pharmacologic causes of bone loss in order to prevent fractures, especially in patients considered to be at very high risk due to recent fractures, propensity to falls, and/or comorbidities. Glucocorticoids, aromatase inhibitors, and many other drugs administered for a variety of chronic diseases are often noted to be taken during medical visits, in both inpatient and outpatient encounters. Medical personnel should always review the reconciled medications to safeguard the bone health of patients. This chapter focuses on the most common medications that cause osteoporosis, with attention to clinical aspects and management strategies in these situations.
Uncertainty Quantification in Solidification Modelling

Numerical models have been used to simulate solidification processes, to gain insight into physical phenomena that cannot be observed experimentally. Often validation of such models has been done through comparison to a few or single experiments, in which agreement is dependent on both model and experimental uncertainty. As a first step to quantifying the uncertainty in the models, sensitivity and uncertainty analysis were performed on a simple steady state 1D solidification model of continuous casting of weld filler rod. This model includes conduction, advection, and release of latent heat was developed for use in uncertainty quantification in the calculation of the position of the liquidus and solidus and the solidification time. Using this model, a Smolyak sparse grid algorithm constructed a response surface that fit model outputs based on the range of uncertainty in the inputs to the model. The response surface was then used to determine the probability density functions (PDF's) of the model outputs and sensitivities of the inputs. This process was done for a linear fraction solid and temperature relationship, for which there is an analytical solution, and a Scheil relationship. Similar analysis was also performed on a transient 2D model of solidification in a rectangular domain.
SU-B-213-00: Education Council Symposium: Accreditation and Certification: Establishing Educational Standards and Evaluating Candidates Based on these Standards

The North American medical physics community validates the education received by medical physicists and the clinical qualifications for medical physicists through accreditation of educational programs and certification of medical physicists. Medical physics educational programs (graduate education and residency education) are accredited by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP), whereas medical physicists are certified by several organizations, the most familiar of which is the American Board of Radiology (ABR). In order for an educational program to become accredited or a medical physicist to become certified, the applicant must meet certain specified standards set by the appropriate organization. In this Symposium, representatives from both CAMPEP and the ABR will describe the process by which standards are established as well as the process by which qualifications of candidates for accreditation or certification are shown to be compliant with these standards. The Symposium will conclude with a panel discussion. Learning Objectives: 1. Recognize the difference between accreditation of an educational program and certification of an individual 2. Identify the two organizations primarily responsible for these tasks 3. Describe the development of educational standards 4. Describe the process by which examination questions are developed GS is Executive Secretary of CAMPEP.
Immune regulation by low doses of the DNA methyltransferase inhibitor 5-azacitidine in common human epithelial cancers.

// Huili Li 1,* , Katherine B. Chiappinelli 1,* , Angela A. Guzzetta 1,* , Hariharan Easwaran 1 , Ray-Whay Chiu Yen 1 , Rajita Vatapalli 1 , Michael J. Topper 1 , Jianjun Luo 1 , Roisin M. Connolly 1,2 , Nilofer S. Azad 1 , Vered Stearns 1,2 , Drew M. Pardoll 1 , Nancy Davidson 3 , Peter A. Jones 4 , Dennis J. Slamon 5 , Stephen B. Baylin 1 , Cynthia A. Zahnow 1 , Nita Ahuja 1,6 1 Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA 2 Breast Cancer Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA 3 Department of Medicine, University of Pittsburgh Cancer Institute and UPMC CancerCenter, Pittsburgh, PA 4 Departments of Urology and Biochemistry and Molecular Biology, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 5 The Jonsson Comprehensive Cancer Center, University of California-Los Angeles 6 Department of Surgery, School of Medicine, Johns Hopkins University, Baltimore, MD, USA * These authors contributed equally to the work Correspondence: Nita Ahuja, email: // Cynthia A. Zahnow, email: // Keywords : Epigenetics, immune, cancers, DNA methyltransferase inhibitor, interferon, methylation, antigen processing Received : February 4, 2014 Accepted : February 16, 2014 Published : February 16, 2014 Abstract Epigenetic therapy is emerging as a potential therapy for solid tumors. To investigate its mechanism of action, we performed integrative expression and methylation analysis of 63 cancer cell lines (breast, colorectal, and ovarian) after treatment with the DNA methyltransferase inhibitor 5-azacitidine (AZA). Gene Set Enrichment Analysis demonstrated significant enrichment for immunomodulatory pathways in all three cancers (14.4-31.3%) including interferon signaling, antigen processing and presentation, and cytokines/chemokines. Strong upregulation of cancer testis antigens was also observed. An AZA IMmune gene set (AIMs) derived from the union of these immunomodulatory pathway genes classified primary tumors from all three types, into “high” and “low” AIM gene expression subsets in tumor expression data from both TCGA and GEO. Samples from selected patient biopsies showed upregulation of AIM genes after treatment with epigenetic therapy. These results point to a broad immune stimulatory role for DNA demethylating drugs in multiple cancers.
Software Licensing: Pay-Per-Use versus Perpetual

Piracy has been a major problem for perpetually licensed software. Usage-based licensing architecture such as pay-per-use or software-as-a-service can offer technology-based protection against piracy. We provide an analytical framework to examine the economic implications of pay-per-use versus perpetual licensing in a market with potential piracy, network effect, and heterogeneous consumers in terms of marginal usage benefit and acquisition costs for pirated software. We show that the potential piracy rate, the user inconvenience cost of pay-per-use licensing, consumer heterogeneity, and the network strength are important factors determining a vendor’s optimal choice of licensing architecture. While perpetual licensing tends to be optimal when consumers have homogeneous valuations, pay-per-use is more profitable than perpetual licensing or mixed licensing in markets with heterogeneous consumers and low user inconvenience costs. If the inconvenience cost is low enough, pay-per-use will be more profitable than perpetual licensing even if the market has no potential piracy. The presence of network effect also favors pay-per-use over perpetual licensing; if the network effect is strong, pay-per-use will always dominate perpetual licensing regardless of the inconvenience cost or the potential piracy. With more heterogeneous consumers, higher potential piracy, lower inconvenience costs, and stronger network effects, pay-per-use licensing yields not only higher vendor profits but also a higher social surplus than perpetual licensing. Important managerial implications are also discussed.
Inhibition by dithiothreitol of the utilization of glutamine by carbamyl phosphate synthetase. Evidence for formation of hydrogen peroxide.

Abstract The glutaminase activity of glutamine-dependent carbamyl phosphate synthetase (Escherichia coli) and that of the separated light subunit of this enzyme, as well as the glutaminedependent synthetase activity catalyzed by the native enzyme, are inactivated by incubation in air with relatively low concentrations (0.025 to 1 mm) of dithiothreitol; oxidized dithiothreitol does not inhibit. Other mercaptans (glutathione, 2-mercaptoethanol, dithioerythritol) also inhibit. Low concentrations of dithiothreitol under nitrogen and high concentrations (5 to 25 mm) of dithiothreitol in air do not inactivate the glutamine-related functions of the separated light subunit or of the native enzyme. However, enzyme preparations that have been inhibited by low concentrations of dithiothreitol in air are not readily reactivated by treatment with high concentrations of dithiothreitol. Incubation of the native enzyme with hydrogen peroxide (0.2 mm) also inhibits the glutamine-dependent activities. In distinction, treatment of the enzyme with either hydrogen peroxide or low concentrations of dithiothreitol in air does not affect either the ammonia-dependent synthetase activity or the synthesis of ATP from ADP and carbamyl phosphate, while the bicarbonate-dependent hydrolysis of ATP is stimulated moderately by both of these reagents. The addition of catalase as well as the addition of l-albizziin, l-glutamine, EDTA, or a mixture of ATP, magnesium ions, bicarbonate, and l-ornithine protect against inhibition of the glutamine-dependent synthetase activity by dithiothreitol. Neither l-ornithine (a positive allosteric effector) nor UMP (a negative allosteric effector) significantly affects the inhibition while a high protein concentration (10 mg per ml) protects against inhibition. The glutaminase activity of the separated light subunit, like that of the intact enzyme, is inhibited by the glutamine analog l-2-amino-4-oxo-5-chloropentanoic acid (chloroketone); l-glutamine or l-albizziin can protect against this inhibition. [14C]Chloroketone binds to the dithiothreitol-inhibited enzyme to the same extent as it does to the native enzyme; such binding is reduced in the presence of glutamine. The most straightforward interpretation of the present results is that metal ion-catalyzed oxidation of dithiothreitol produces hydrogen peroxide which oxidizes one or more critical residues in the glutamine binding site of the light subunit. Such oxidation does not involve the sulfhydryl group which in the native enzyme reacts with chloroketone, nor does it involve a sulfhydryl group on the light subunit whose reaction with N-ethylmaleimide in the presence of ATP, magnesium ions, and bicarbonate, leads to loss of glutamine-dependent synthetase activity and to enhanced glutaminase activity.
"Entransy," and Its Lack of Content in Physics

Here, I show that “entransy” has no meaning in physics, because, at bottom, it rests on the false claim that in order to transfer heat to a solid body of thermodynamic temperature T, the heat transfer must be proportional to T. Entransy “dissipation” is a number proportional to well known measures of irreversibility such as entropy generation and lost exergy (destroyed available work). Furthermore, the “principle of entransy dissipation minimization” adds nothing to existing work based on minimum entropy generation, minimum thermal resistance, and constructal law. The broader trend illustrated by the entransy hoax is that it is becoming easy to take an existing idea, change the keywords, and publish it as new.
Lifetime cumulative number of menstrual cycles and serum sex hormone levels in postmenopausal women

Objective Lifetime cumulative number of menstrual cycles is related to breast cancer risk. The aim of this study is to investigate the relation between this index and serum sex hormone levels in postmenopausal women.
Random vibration analysis of a non-linear system with dry friction damping by the short-time gaussian cell mapping method

Abstract Some vibration attenuation devices make use of material non-linearity and dry friction damping mechanisms. Such devices are often exposed to a random vibration environment. It is important for engineers to be able to calculate the random vibration response of a system involving these devices, and thereby to predict the fatigue life of the device and the reliability of the system. However, the analytical study of random vibration problems of such a system is usually difficult. This paper extends the previously developed generalized cell maping method based upon the short-time Gaussian approximation (GCM/STGA) to systems with dry friction damping. In the paper, the non-linear moment equations of the state variables of a general non-linear system with dry friction damping are derived for the construction of the one-step short-time Gaussian transition probability matrix of the GCM/STGA method. Transient and steady state solutions of some numerical examples are presented. Excellent agreement is found between the results of the present method and the available exact solutions or simulation data. This study indicates that the GCM/STGA method is well suited to random vibration studies of complex systems with dry friction damping, and offers an attractive tool for random vibration analysis of these systems.
Individually optimized bottom-emitting vertical-cavity lasers and bottom-illuminated resonant photodetectors sharing the same epitaxial structure

We demonstrate a novel design that allows fabrication of substrate input/output photodetectors and lasers on the same substrate by selective oxidation of the bottom mirror.
Estrogen treatment protects GABAB inhibition in the dentate gyrus of female rats after kainic acid-induced status epilepticus

Summary: Purpose: We used the paired-pulse inhibition paradigm to determine whether the cell loss in the hilus of the dentate gyrus of female rats after kainic acid (KA)-induced status epilepticus (SE) is associated with functional changes in the dentate gyrus. Additionally, we determined whether the lost function could be preserved by using estrogen neuroprotection. Methods: Female rats were ovariectomized and treated either with estrogen replacement (four doses of 2 μg of estradiol every 24 h: two doses before SE, two doses after) or oil. SE was induced by I.P. administration of KA (16 mg/kg) and terminated after 5 h with pentobarbital. After 2 days, hippocampal/dentate gyrus slices were prepared. Population spikes were recorded in the granule cell layer as a response to mixed perforant-path stimulation (10- to 1,000-ms interstimulus intervals). Ratios of the test response to conditioning response were evaluated. γ-Aminobutyric acid type B (GABAB) receptors were blocked with 400 μM CGP 35348. Results: In slices from oil-treated rats, SE induced a loss of paired-pulse inhibition in the dentate gyrus at the interstimulus intervals marking intermediate facilitation and late depression. There was no such loss of paired-pulse inhibition in estrogen-treated rats. CGP 35348 was unable to alter paired-pulse inhibition in slices form oil-treated rats. In slices from estrogen-treated rats, CGP decreased paired-pulse inhibition at 50–150-ms interstimulus intervals. Comparison of paired-pulse inhibition in slices from oil-treated rats with slices from estrogen-treated rats with CGP 35348 revealed a GABAB-independent difference at interstimulus intervals >300 ms. Conclusions: Our study demonstrated that there is a complete loss of GABAB receptor–mediated inhibition after KA-induced SE in the dentate gyrus. Pretreatment with estrogen can save GABAB-receptor function, probably by neuroprotection of neurons containing the postsynaptic GABAB receptors.
DISTRIBUTION OF BEAN AND WHEAT INOSITOL PHOSPHATE ESTERS DURING AUTOLYSIS AND GERMINATION

Ion-exchange chromatography was used to follow changes in inositol phosphate esters of California small white beans and hard red winter wheat during autolysis and germination. Untreated bean extracts contained appreciable quantities of lower phosphate esters, while wheat extracts contained only inositol hexaphosphate (IHP). Autolysis in beans at both 35 and 55°C was slow (30% of IHP still present after 48 hr). Over 80% of wheat IHP was hydrolyzed in 4 hr at both temperatures. During autolysis bean extracts contained appreciable quantities of lower phosphate esters while wheat chromatograms showed trace amounts. Germination of the seeds for 2, 4 and 7 days produced similar patterns of change in the phosphate esters as in autolysis. The use of wheat phytase to rapidly reduce phytic acid in bean preparations is presented.
Recent Developments in Electronic, Functional, and Biological Thin Films

The use of surface modification by humans dates back several millennia. As noted by Myers, the art of Cro-Magnon man in 15,000 B.C. can be considered to be a decorative coating. Oddy noted that applying gold to surfaces has been performed for at least 5000 years. Processing of thin films for applications other than gilding began in earnest in the nineteenth century. At the beginning of the nineteenth century, Luigi Brugnatelli used electroplating to deposit gold; by the middle of that century, deposition of a variety of metals had been demonstrated. Sir Robert Grove described a process that he termed ‘‘cathodic disintegration’’ in 1852; Sir John Thompson later renamed this process ‘‘sputtering.’’ As noted by Mattox, Michael Faraday described sputtering within a glow discharge tube for deposition of films in the mid-nineteenth century. At the turn of the last century, Thomas Edison used sputtering to deposit gold coatings on master wax cylinders, which were subsequently used to produce ‘‘Gold Moulded Records.’’ The origin of chemical vapor deposition has been traced to early studies by von Guericke and Henry. It was used for development of light bulb materials in the 1880s and for purification of refractory metals in the 1940s. Over the past half century, rapid developments in thin film technology were associated with increases in complexity and reductions in size of electronic and optical devices. For example, Smith and Turner used evaporation by a ruby laser to create films of a variety of materials, including As2S3, Ge, MoO3, PbTe, Sb2S3, Se, Te, and ZnTe. Currently, pulsed laser deposition is commonly used for deposition of a variety of thin films, including multicomponent systems and biologically relevant materials, at low temperatures. At the beginning of the twenty-first century, significant thin film research activities involve the development of thin films for medical and energy applications. In this issue, Gupta et al. considered the protein adsorption and wettability of composite materials containing ultrahigh molecular weight polyethylene, hydroxyapatite, alumina, and carbon nanotubes; these materials have potential use in joint replacement prostheses. Palkowski et al. created a three-layered stainless steel/polypropylene copolymer/stainless steel sandwich sheet material with biomimetic properties. Skoog et al. deposited ultrananocrystalline diamond films on microporous silicon nitride membranes using microwave plasma chemical vapor deposition and evaluated the growth of human epidermal keratinocytes on these materials. Shet et al. prepared zinc oxide thin films using radio frequency sputtering in the presence of a gas ambient containing argon and nitrogen. They demonstrated that aligned nanoscale structures with enhanced photoelectrochemical response were prepared under an appropriate gas ambient. It is hoped that this special issue helps to generate discussions in industry, academia, and government regarding use of thin film technology for electronic, functional, and biological applications.
Increasing Communication in Children with Concurrent Vision and Hearing Loss

Nine children with complex communication needs and concurrent vision and hearing losses participated in an intervention program aimed at increasing intentional prelinguistic communication. The intervention constituted a pilot, descriptive study of an adapted version of prelinguistic milieu teaching, hence referred to as A-PMT. In A-PMT, natural gestures and vocalizations were targeted in child-focused, one-on-one activities conducted by a member of the project staff. Adaptations included using more physical prompts than in other forms of PMT and using means other than directed eye gaze to determine directionality of gestures. All nine participants increased their rates of initiated, intentional communication substantially during the course of intervention; in addition, each participant acquired new forms of natural gestures. Results were limited primarily to requests (as opposed to other communication functions). Discussion centers on how to promote more generalized communication developments in future implementations of the program.
Strategy and Environment: A Conceptual Integration

An elaboration of the concepts of strategy and environment can be achieved by categorizing environment into its objective and perceived states, and by subdividing strategy according to content (outcomes) or process. The objective environment can be further categorized into “task” and “general.” An alternative subdivision of strategy is primary (domain selection) and secondary (competitive approach). The concepts of strategy and environment are integrated in that primary strategy concerns opportunities in the general environment and secondary strategy involves navigating within a task environment.
Cytoplasmic Reversion of cms-S in Maize: Association with a Transpositional Event

Spontaneous reversion to fertility in S male-sterile cytoplasm of maize is correlated with the disappearance of the mitochondrial plasmid-like DNA's, S-1 and S-2, and changes in the mitochondrial chromosomal DNA. Hybridization data indicate that one of the plasmid-like DNA's, S-2, is prominently involved in the mitochondrial DNA rearrangements.
HPRT mutations in vivo in human CD 34+ hematopoietic stem cells

The HPRT mutations in T lymphocytes are widely utilized as biomarkers of environmental exposure and effect. The HPRT gene detects a wide variety of mutation types, many of which are similar at the molecular level to those found in oncogenes in cancers. However, it remains to be determined whether the assay for mutations in T lymphocytes is reflective of mutagenic events in tissues or cells which have high frequencies of malignancy in humans. We now demonstrate that the HPRT gene can be utilized to detect mutations in myeloid stem cells, which are frequent progenitor cells of leukemias. This myeloid stem cell assay shows an age related increase in mutation at HPRT and also detects increases in mutant frequency (M-MF) in patients who have undergone chemotherapy. The myeloid mutants are confirmed to have mutations in the HPRT gene by DNA sequence analysis. Increases in M-MF are seen as expected in the clonally unstable myeloid stem cells of patients with myelodysplastic syndromes; however, unexpectedly these patients also have elevated T-lymphocyte mutant frequencies (T-MF). A good correlation is shown between M-MFs and T-MFs in the same patients. Thus, it appears that the T-lymphocyte assay, which is technically much less demanding than the myeloid assay, appears to faithfully represent the frequency of mutagenic events in the myeloid lineage.
Collateral constraints and the amplification mechanism

Abstract Kiyotaki and Moore (J. Polit. Economy 105 (1997) 211) have offered a theory for how common shocks to credit-constrained firms are amplified through changes in collateral values and transmitted as fluctuations in output. I clarify and extend their model by showing that their collateral amplification mechanism is not robust to the introduction of markets that allow these firms to hedge against common shocks. A theory of incomplete hedging is proposed in which the supply of hedging available in the economy is constrained by the aggregate value of collateral. I illustrate how the constraint reinstates amplification effects and discuss empirical implications of this new mechanism.
Preserving the ethical propriety of statistical devices.

Abstract C. D. Herrera (1996) introduced an innovative argument against the use of deception in psychological research. In essence, Herrera contended that because of the presumed problems with null hypothesis statistical testing, researchers could not justify their continued use of deception in research. Although this is an interesting argument, there are several alternative perspectives that must be considered. In examining these alternatives, the author concluded that psychologists may continue to use deception under certain circumstances outlined in the American Psychological Association's ethical code of conduct.
Synthesis and ligand substitution reactions of [Ta(CO)5NH3]−1☆

Abstract Protonation of Na 3 [Ta(CO) 5 ] in liquid ammonia provides the thermally unstable Na[Ta(CO) 5 NH 3 ], which may be isolated as the crystalline and deep violet salt [Ph 4 As][Ta(CO) 5 NH 3 ]. Sodium amminepentacarbonyltantalate(1−) reacts with PMe 3 , PPh 3 , P(OMe) 3 , AsPh 3 , SbPh 3 , CNtBu and CN − at about 0°C in NH 3 /THF to give exclusively the corresponding [Ta(CO) 5 L] z . These have been isolated as tetraethylammonium salts in 54–84% yields.
Reflections of a cancer survivor/research scientist.

For more than 50 years, Cancer has been devoted to exploring every facet of malignant neoplasia, from morphology to therapy, from epidemiology to biology, from historical perspective to basic science. One aspect, however, needs emphasis, namely, the human being who bears the burden of the cancer. For this reason and with the encouragement of the Editor, we have undertaken to remedy this situation by directing attention to the fears and frustrations, hopes and expectations, and feelings and thoughts of all kinds of the person who has cancer, who is worried about it, and who is dependent on physicians specialized in its diagnosis and management. For doctors to be understanding of the very deep needs of patients with cancer, it is requisite that they be privy to authentic, but often unspoken, expressions of a patient's anxieties about physical and emotional pain, loss of control over personal destiny, and plain dread of dying and of the end of cherished relationships.
Shock deformation of Inconel 600 alloy - Effect of fine coherent precipitates on explosive-shock hardening

Sheet samples of pure nickel and Inconel 600 alloy (76% Ni, 16% Cr, 7% Fe) containing a fine precipitate were simultaneously shock loaded in sandwich assemblies at pressures of 50, 100, 150, 200, and 370 kbar by a planar pulse of roughly 2‐μsec duration explosively initiated by a flying plate. The residual microhardness of the nickel was observed to saturate above 300 kbar while that for Inconel continued to increase steadily. Examination of the nickel substructures by transmission electron microscopy revealed a steadily decreasing cell size with increasing shock pressure; with almost no evidence of deformation twins at 370 kbar. The Inconel substructure was characterized by planar dislocation arrays which included an increasing concentration of dipoles and elongated loops to 200 kbar; while at 370 kbar deformation twins having an average thickness of 150 A and occupying 19% of the volume were observed. The coherent precipitates in the Inconel matrix were observed to become incoherent at pressures above 50 kbar, with the concomitant production of dislocation tangles and loops at the particle‐matrix interface. The precipitates were observed to enhance shock hardening by acting as sources for dislocation dipoles and elongated loops.
Chronic graft-versus-host disease.

bidity following BMT is graft-versus-host disease (GVHD). In several large recent trials, 40‐ 60% of patients surviving more than 100 days have developed chronic GVHD (1‐ 3). The incidence of chronic GVHD is expected to rise due to several trends in transplantation. The incidence of chronic GVHD increases with age, and more centers are now routinely transplanting to age 65. Matched unrelated donor transplants (MUD) are being done with increasing frequency. Unfortunately, over 60% of patients who undergo this type of transplant will develop chronic GVHD (4,5). Donor lymphocyte infusion (DLI) are routinely being used to treat patients with relapse disease after allogeneic transplant. This procedure can be effective but is associated with a high risk of chronic GVHD. The use of allogeneic peripheral blood as a stem cell source may have a lower peritransplant mortality rate when compared to marrow but as high or higher incidence of chronic GVHD. For these reasons, chronic GVHD must be considered as one of the major problems still facing the field of blood and marrow transplantation. PATHOGENESIS Chronic GVHD had been a difficult problem to study systematically. Clinical studies in patients with chronic GVHD are hampered by the fact that patients are frequently back in their local communities, thus, at a distance from the transplant center by the time they develop chronic GVHD. Early manifestations of the disease may be missed by physicians unfamiliar with the disease. The ability to investigate the disease and the response to therapy may be impaired by the constraints of distance. Many
Presidential anonymity: Rhetorical identity management and the mystification of political reality

This essay explores the dimensions of presidential anonymity, a privileged and covert form of rhetorical identity management. Using not‐for‐attribution White House plants as a basis for analysis, we contend that anonymity mystifies the public's political reality by masking a chief executive's identity and rhetorical motives. As such, anonymity enables a president to circumvent the public forum, to disseminate self‐serving and untoward information, and to manipulate the press. We conclude that anonymity serves the president's interests at the expense of the citizenry's right‐to‐know and ability to render reasoned judgments. Six implications of presidential anonymity are discussed.
Evidence that the subunit structure of gonadotropin receptor is preserved during regression of rat corpus luteum

Abstract The level of hCG LH receptor has been shown to undergo marked changes during the life span of rat corpus luteum. To evaluate whether these fluctnations are due to changes in the receptor subunit structure or receptor protein content, the 125I-hCG binding activity and the receptor subunit structure were determined during different time periods of pseudopregnancy. The maximum 125I-hCG binding activity was observed on day 7, after which it decreased by 20 and 45% on day 11 and day 14, respectively. The Scatchard analysis of 125I-hCG binding data showed that the decrease in binding activity was caused by a change in the number of binding sites rather than a change in the binding affinity. The LH hCG receptor in ovarian membranes obtained on days 7, 11 and 14 were then characterized by the method of affinity cross-linking. All four subunits of the LH hCG receptor were detected in the ovarian membranes at all stages while the intensity decreased parallel to a decrease in hCG binding from day 7 to day 14. These results suggest that the decrease in 125I-hCG binding activity in rat ovarian membranes from day 7 to day 14 of pseudopregnancy is due to a decrease in receptor concentration rather than a change in the receptor subunit structure.
Determination of transition temperatures and crystalline content of linear, high‐molecular‐weight polyethylene by proton NMR spectroscopy

Decomposition of the proton NMR spectra of linear, high-molecular-weight polyethylene into a Gaussian function and a Lorentzian function is discussed in terms of the Wilson-Pake two-component method for an inhomogeneous system. The results of a Goldman-Shen experiment indicate that spin diffusion does not strongly couple the two regions. The temperature dependence of the Lorentzian (mobile) fraction is fitted to a function derived from the relation of English and Zoller. The critical temperatures give estimates of thermal transitions: Tα = 328 (± 5) K and Tγ = 163 (± 4) K. The fraction of Lorentzian spins excited by the γ relaxation correlates with the amorphous content of the sample as determined by differential scanning calorimetry and x-ray diffraction.
Bicalutamide alone prior to brachytherapy achieves cytoreduction that is similar to luteinizing hormone-releasing hormone analogues with less patient-reported morbidity.

Abstract Objectives To compare the impact of bicalutamide (B) vs. luteinizing hormone-releasing hormone analogues (LHRHa) on prostate volume, patient-reported side effects, and postimplant urinary toxicity in the setting of interstitial brachytherapy for early-stage prostate cancer. Methods Between May 1998 and January 2004, 81 patients received androgen-deprivation therapy (ADT) for cytoreduction prior to interstitial brachytherapy alone. Fifty-six patients received LHRHa and 25 patients received B. Prostate volumes were measured prospectively prior to initiating therapy, and then intraoperatively at the time of implant by a single, blinded ultrasonographer. Patient-reported quality of life data were obtained prospectively, and postimplant urinary toxicity (catheter dependency and need for surgical intervention) was recorded during follow-up. Median follow-up was 53 (range 23–78) months. Results The median percentage prostate volume reductions of 26% for B and 32% for LHRHa were not statistically different (P = 0.61). Decrements in libido (92% vs. 44%, P Conclusions The degree of prostate downsizing with B is similar to that achieved with LHRHa. B was associated with fewer patient-reported sexual side effects and similar urinary morbidity. A randomized trial is needed to establish whether LHRHa or B should be the standard of care for prostate downsizing before interstitial brachytherapy.