cssi/SciSciGPT-SciSciNet huggingface dataset:
Inadequate Risk Adjustment Impacts Geriatricians' Performance on Medicare Cost and Quality Measures.

OBJECTIVES Medicare value-based payment programs evaluate physicians' performance on their patients' annual Medicare costs and clinical outcomes. However, little is known about how geriatricians, who disproportionately provide care for medically complex older adults, perform on these measures. DESIGN A retrospective study using multivariable regression methods to estimate the association of geriatric risk factors with annualized Medicare costs and preventable hospitalization rates and to compare geriatricians' performance on these outcomes to other primary care physicians (PCPs) under standard Medicare risk adjustment and after adding additional adjustment for geriatric risk factors. SETTING Eight years (2006-2013) of cohort data from the Medicare Current Beneficiary Survey. PARTICIPANTS Medicare beneficiaries, aged 65 years and older, with primary care services contributing 27 027 person-years of data. MEASUREMENTS Outcomes were costs and preventable hospitalization rates; geriatric risk factors were patient frailty, long-term institutionalization, dementia, and depression. RESULTS Geriatricians were more likely to care for patients with frailty (22.8% vs 14.1%), long-term institutionalization (12.0% vs 4.7%), dementia (21.6% vs 10.2%), and depression (23.6% vs 17.4%) than other PCPs (P < .001 for each). Under standard Medicare risk adjustment, geriatricians performed more poorly on costs compared to other PCPs (observed-expected [O-E] ratio = 1.24 vs 0.99) and preventable hospitalizations (O-E ratio = 1.16 vs 0.98). Adding frailty, institutionalization, dementia, and depression to risk adjustment improved geriatricians' performance on costs by 25% and on preventable hospitalization rates by 35%, relative to other PCPs. Concurrent-year risk prediction that removed the influence of unpredictable acute events further improved geriatricians' performance vs other PCPs (O-E ratio = 0.99 vs 1.00). CONCLUSION Medicare should consider risk adjusting for frailty, long-term institutionalization, dementia, and depression to avoid inappropriately penalizing geriatricians who care for vulnerable older adults. J Am Geriatr Soc 68:297-304, 2020.
African-centric TP53 variant increases iron accumulation and bacterial pathogenesis but improves response to malaria toxin.

A variant at amino acid 47 in human TP53 exists predominantly in individuals of African descent. P47S human and mouse cells show increased cancer risk due to defective ferroptosis. Here, we show that this ferroptotic defect causes iron accumulation in P47S macrophages. This high iron content alters macrophage cytokine profiles, leads to higher arginase level and activity, and decreased nitric oxide synthase activity. This leads to more productive intracellular bacterial infections but is protective against malarial toxin hemozoin. Proteomics of macrophages reveal decreased liver X receptor (LXR) activation, inflammation and antibacterial defense in P47S macrophages. Both iron chelators and LXR agonists improve the response of P47S mice to bacterial infection. African Americans with elevated saturated transferrin and serum ferritin show higher prevalence of the P47S variant (OR = 1.68 (95%CI 1.07–2.65) p = 0.023), suggestive of its role in iron accumulation in humans. This altered macrophage phenotype may confer an advantage in malaria-endemic sub-Saharan Africa. A polymorphism in human TP53 (P47S) that predominantly exists in individuals of African descent affects ferroptosis. Here, the authors show that this results in iron accumulation in macrophages leading to more productive infection by intracellular bacteria but improved anti-inflammatory response to the malarial toxin hemozoin.
Constrained nuclear-electronic orbital density functional theory: Energy surfaces with nuclear quantum effects

The nuclear-electronic orbital (NEO) framework enables the incorporation of nuclear quantum effects by treating both electrons and specific key nuclei quantum-mechanically. The conventional NEO method predicates on the controversial Born–Oppenheimer separation between classical and quantum nuclei, and its potential energy surface only depends on the coordinates of classical nuclei. In this paper, based on the fact that quantum nuclei are relatively localized, we develop the constrained nuclear-electronic orbital density functional theory (cNEO-DFT) by imposing a constraint on the expectation value of the quantum nuclear position. In this way, an extended NEO energy surface is obtained, which also depends on the quantum nuclear position. Compared to the potential energy surface obtained from conventional DFT, the extended NEO energy surface incorporates the nuclear quantum effects, which have notable impacts on the energy profile. Furthermore, cNEO-DFT can facilitate the location of NEO stationary states. It potentially can be used in geometry optimization, transition states search, and the calculation of reaction dynamics.
Overcoming small minirhizotron datasets using transfer learning

Abstract Minirhizotron technology is widely used to study root growth and development. Yet, standard approaches for tracing roots in minirhiztron imagery is extremely tedious and time consuming. Machine learning approaches can help to automate this task. However, lack of enough annotated training data is a major limitation for the application of machine learning methods. Transfer learning is a useful technique to help with training when available datasets are limited. In this paper, we investigated the effect of pre-trained features from the massive-scale, irrelevant ImageNet dataset and a relatively moderate-scale, but relevant peanut root dataset on switchgrass root imagery segmentation applications. We compiled two minirhizotron image datasets to accomplish this study: one with 17,550 peanut root images and another with 28 switchgrass root images. Both datasets were paired with manually labeled ground truth masks. Deep neural networks based on the U-net architecture were used with different pre-trained features as initialization for automated, precise pixel-wise root segmentation in minirhizotron imagery. We observed that features pre-trained on a closely related but relatively moderate size dataset like our peanut dataset were more effective than features pre-trained on the large but unrelated ImageNet dataset. We achieved high quality segmentation on peanut root dataset with 99.04% accuracy at the pixel-level and overcame errors in human-labeled ground truth masks. By applying transfer learning technique on limited switchgrass dataset with features pre-trained on peanut dataset, we obtained 99% segmentation accuracy in switchgrass imagery using only 21 images for training (fine tuning). Furthermore, the peanut pre-trained features can help the model converge faster and have much more stable performance. We presented a demo of plant root segmentation for all models under https://github.com/GatorSense/PlantRootSeg .
The Effects of Sucrose, Silver Nitrate, Plant Growth Regulators, and Ammonium Nitrate on Microrhizome Induction in Perennially-Cultivated Ginger (Zingiber officinale Roscoe) From Hue, Vietnam

The number of research on ginger microrhizome production is low, despite awareness of the drawbacks to the traditional method of cultivation and the known health benefits associated with ginger essential oils. We examined the effects of several factors on microrhizome induction in order to create a production protocol for the cultivar found in Hue, Vietnam. To determine the optimal conditions for ginger microrhizome production, different concentrations of sucrose, plant growth regulators, ammonium nitrate, and silver nitrate were investigated. Microrhizome fresh weight and diameter were increased to the maximum values with application of BAP (6-benzyl amino purine), NAA (α- naphthaleneacetic acid), IBA (indole-3-butyric acid), and a low ammonium nitrate concentration, with 0.433 g at 9.03 mm, 0.437 g at 9.73 mm, 0.478 g at 10.80 mm, and 0.449 g at 9.53 mm, respectively. Additionally, we demonstrated that kinetin has an inhibitory effect on microrhizome growth. The biggest microrhizomes were grown on MS media containing the optimal concentrations for each factor – 80 g/L sucrose, 1.9 mg/L AgNO 3 , 550 mg/L ammonium nitrate, 4 mg/L BAP, 6 mg/L NAA, and 4 mg/L IBA.
Load transfer between thin steel plates and ultra-high performance concrete through different types of shear connectors

Abstract The unique compressive and tensile characteristics of ultra-high performance concrete (UHPC) have enabled advancement of non-traditional shear connectors to provide composite action between UHPC and steel elements. The focus of the current technical literature in this area has been mainly on shear connectors that are used for the load transfer between flange plates and UHPC slabs. There remains a knowledge gap in the applicability of conventional and novel types of shear connectors to thin steel plates, such as web or stiffener plates. This knowledge is critical for the advancement of design guides for steel-UHPC composite members with fully embedded steel shapes and design guides for rehabilitation and reinforcement of the web plate of steel girders. This paper presents the experimental evaluation of three simple shear connectors: (1) traditional headed studs, (2) demountable threaded bars secured with nuts and (3) UHPC dowel connectors. The experimental results show that the connection is governed by fracture of the stud or threaded bar shank adjacent to the weld or at the interface between the web plate and the nut, respectively. The UHPC dowel connectors display brittle interface shear failure of the UHPC, followed by ductile pull-out behavior of the steel fibers. For large-diameter UHPC dowels, it was observed that yielding of the steel plate in bearing controls the capacity because of the relatively small thickness of the steel plate. The failure mechanisms, capacity and stiffness values, and strain demands on the embedded steel plates are presented and discussed. These experimental results are expected to broaden the knowledge of shear connectors incorporated into relatively thin plates and embedded in UHPC.
Children with attention-deficit/hyperactivity disorder spend more time in hyperconnected network states and less time in segregated network states as revealed by dynamic connectivity analysis.

Abstract Previous studies in children with attention-deficit/hyperactivity disorder (ADHD) have observed functional brain network disruption on a whole-brain level, as well as on a sub-network level, particularly as related to the default mode network, attention-related networks, and cognitive control-related networks. Given behavioral findings that children with ADHD have more difficulty sustaining attention and more extreme moment-to-moment fluctuations in behavior than typically developing (TD) children, recently developed methods to assess changes in connectivity over shorter time periods (i.e., “dynamic functional connectivity”), may provide unique insight into dysfunctional network organization in ADHD. Thus, we performed a dynamic functional connectivity (FC) analysis on resting state fMRI data from 38 children with ADHD and 79 TD children. We used Hidden semi-Markov models (HSMMs) to estimate six network states, as well as the most probable sequence of states for each participant. We quantified the dwell time, sojourn time, and transition probabilities across states. We found that children with ADHD spent less total time in, and switched more quickly out of, anticorrelated states involving the default mode network and task-relevant networks as compared to TD children. Moreover, children with ADHD spent more time in a hyperconnected state as compared to TD children. These results provide novel evidence that underlying dynamics may drive the differences in static FC patterns that have been observed in ADHD and imply that disrupted FC dynamics may be a mechanism underlying the behavioral symptoms and cognitive deficits commonly observed in children with ADHD.
Autonomously Autistic: Exposing the Locus of Autistic Pathology

The locus of pathology exists not in the autistic person, but in the interaction between a hostile environment and the subjugated autistic. It is essential for parents, practitioners, educators, and autistic people themselves to ask the crucial question— Is the autistic a machine, or an organism? Are we active agents in our own embodied experience, or are we a locus of behavior? It is not with defiance, but autonomy, that I declare as an autistic person— I am not a manifestation of stimuli and response. I am agential. I am Autonomously Autistic.
Set Values for Mean Field Games

In this paper we study mean field games with possibly multiple mean field equilibria. Instead of focusing on the individual equilibria, we propose to study the set of values over all possible equilibria, which we call the set value of the mean field game. When the mean field equilibrium is unique, typically under certain monotonicity conditions, our set value reduces to the singleton of the standard value function which solves the master equation. The set value is by nature unique, and we shall establish two crucial properties: (i) the dynamic programming principle, also called time consistency; and (ii) the convergence of the set values of the corresponding $N$-player games. To our best knowledge, this is the first work in the literature which studies the dynamic value of mean field games without requiring the uniqueness of mean field equilibria. We emphasize that the set value is very sensitive to the choice of the admissible controls. In particular, for the convergence one has to restrict to the same type of equilibria for the N-player game and for the mean field game. We shall illustrate this point by investigating three cases, two in finite state space models and the other in a diffusion model.
Relationship Between Simulated Gadolinium-Based Contrast Agent Injection Profile and Achievable Resolution Metrics in Contrast-Enhanced Magnetic Resonance Angiography.

BACKGROUND Contrast bolus variation during contrast-enhanced magnetic resonance angiography (CE-MRA) acquisition may lead to vessel blurring. PURPOSE To combine knowledge of how contrast signal intensity (SI) evolves for different injection strategies with anatomically familiar parametric computer models to measure and visually assess the effects of a wide range of variables on modeled CE-MRA, and in doing so develop contrast rate injection guidelines. STUDY TYPE Computer modeling. PHANTOM Digital three-dimensional phantom consisting of orthogonal "aorta," 7 mm diameter "renal arteries" (with 57% and 86% diameter stenoses), and 7 mm diameter "superior mesenteric artery" (with 57% diameter stenosis). FIELD STRENGTH/SEQUENCE One millimeter in-plane resolution arterial CE-MRA imaging at 3 T. ASSESSMENT "Background" (time invariant) and "vascular" (time varying) components of the phantom were each Fourier transformed into the spatial frequency domain, the latter modulated by the SI evolution of a contrast bolus of varying "plateau" lengths and "tail" heights. Data are presented as surface plots of stenosis measurement error and blurring vs. a reference-standard injection. STATISTICAL TESTS Descriptive. RESULTS Shorter plateau lengths and lower tail heights resulted in increased measured stenosis error and blurring vs. the reference standard. Under a 44-second acquisition, full width half maximum stenosis error of the 86% stenosis with 25% plateau length and 25% tail height is 24% as compared to that from the reference standard. As plateau length and tail height approach 100%, stenosis error and blurring approach a floor defined by the MR acquisition's limitations. DATA CONCLUSION We propose that to achieve minimal degradation with CE-MRA, one can create a contrast bolus with either 60% plateau and 50% tail height or 80% plateau with any tail. These considerations may well prove to be of practical importance, possibly via manipulating the tail by means of multiphasic contrast injections. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 1.
Functional development of hair cells.

Abstract Embryonic hair cells in chicks and mammals have functional transduction channels and voltage-gated outwardly rectifying potassium (K + ) channels, fast inwardly rectifying channels, and voltage-gated sodium (Na + ) and calcium (Ca 2+ ) channels. Together these channels may participate in spiking by the immature hair cells, which may drive rhythmic or bursting activity of neurons at higher levels of the auditory pathway. The electrical activity of immature hair cells may influence afferent synaptogenesis and differentiation indirectly by promoting neurotrophin release or more directly by glutamatergic transmission. With maturation, a number of changes tend to reduce hair cell spiking: Na + , Ca 2+ , and fast inwardly rectifying channels may become less numerous, whereas outwardly rectifying K + channels become more numerous and diverse. These changes signal the transformation from a developing epithelium with active formation of synaptic contacts to a sensing epithelium where receptor potentials represent the mechanical input in a graded fashion. The composition of the late-arriving outwardly rectifying K + channels is specific to the hair cell's type and location in the sensory epithelium and confers specialized properties on the receptor potentials. Fast, Ca 2+ -gated channels serve high-quality electrical tuning in certain tall hair cells of the chick cochlea. In rodent cochlear hair cells and type I hair cells of chick and rodent vestibular organs, large outwardly rectifying conductances lower the input resistance, enhancing the speed and linearity of voltage responses.
Expressiveness and Distributed Implementation of Conciurrent Calculi with Link Mobility

The π-calculus [6] has introduced in concurrency the concept of link mobility, namely the possibility of communicating values which can afterwards be used as communication means (i.e. channels). Since the original work on the π-calculus, many variants and related paradigms have been introduced, including the asynchronous π-calculus [1,4,5], the π-calculus with input-guarded choice [8], the π-calculus with internal communication [11], the Fusion Calculus [10], and the Join Calculus [2,3]. In general, these variants introduce restrictions that allow for a simpler formal treatment, and/or a more direct modeling of some of the features of distributed systems (like asynchronous communication). Some recent results [7,9] suggest that the expressive power of these variants can be very different when distribution constraints are taken into consideration. In this talk, I will focus on the relative expressiveness of some of these variants, and discuss possible approaches to their distributed implementation.
Gas sensing properties of single-crystalline indium oxide nanowires

Single crystalline In/sub 2/O/sub 3/ nanowires were synthesized and then utilized to construct field effect transistors (FETs) consisting of individual nanowires. Chemical sensors based on these In/sub 2/O/sub 3/ nanowire FETs have been demonstrated. Upon exposure to gaseous molecules such as NO/sub 2/ and NH/sub 3/, the electrical conductance of the In/sub 2/O/sub 3/ nanowire FETs is found to be dramatically modified, accompanied by substantial shifts in the threshold gate voltage. Our In/sub 2/O/sub 3/ nanowire sensors exhibit significantly improved sensitivity to NO/sub 2/ gas, as well as shortened response times compared to most existing solid-state gas sensors. In addition, NH/sub 3/ gas sensing properties of In/sub 2/O/sub 3/ nanowires have also been carefully studied. Change of conductance in opposite directions was observed with different nanowire sensors. We suggest that this differential response is caused by various doping concentrations in the semiconducting In/sub 2/O/sub 3/ nanowires.
Invariance in Statistics

Statistical models, typically consisting of a collection of probability distributions, are used to describe patterns of variability that random variables or data may display. Describing the invariance of such models is often done via group theory. Although the mathematical notion of a group is relatively simple, the ideas of group theory provide a very convenient way to describe how statistical models change when random variables are transformed. In particular, statistical models that are closed under a class of transformations are called invariant. Often this invariance has important implications for inferential problems associated with the model. The principle of invariance asserts that whenever a problem is invariant under a group of transformations, then the solution to the problem should also be invariant. Applications of this principle occur in both estimation and hypothesis-testing problems. For example, maximum-likelihood estimators and likelihood-ratio tests are invariant solutions to inference problems when the model is invariant.
Review of Martha Nussbaum, Not for Profit: Why Democracy Needs the Humanities

Reﬂection on our ways of living, and especially on what is wrong with those ways ofliving, has always been a vital function of philosophy…. [T]he ancient questions,‘Am I living as I am supposed to live?’ ‘Is my life something more than vanity, orworse, mere conformity?’ ‘Am I making the best effort I can to reach … my un-attained but attainable self?’ make all the difference in the world. (Hillary Putman2008)In her new book from Princeton University Press, Not for Proﬁt: Why Democracy Needsthe Humanities (2010), American philosopher Martha Nussbaum calls attention to a new,‘‘silent crisis’’ (1) in education: ‘‘[A] new conception, focused on proﬁt, has taken over, inthe process sidelining the whole idea of imaginative and critical self-development …’’ (4).Throughout the book, Nussbaum focuses on the United States and India as examples ofdemocratic nations with legacies of important educational theory and practice (culminatingin the work of John Dewey and Rabindranath Tagore), which are abandoning those leg-acies today in the pursuit of individual and national proﬁtability. For Nussbaum, theseexamples illustrate what amounts to a ‘‘world-wide crisis,’’ in which ‘‘[t]he future of theworld’s democracies hangs in the balance’’ (2).Of course, education that focuses on socio-economic advancement to the neglect ofmore humanistic aims—making the most of one’s talents, ﬁnding one’s moral bearings,becoming practiced in the virtues, advancing disciplinary knowledge, continuing traditionsof cultural excellence, pursuing political justice, and otherwise living meaningfully—isnothing new; it was, after all, a primary object of scorn for Socrates. But Nussbaum callsattention to the anti-democratic terms in which the agenda of education for wealth andstatus has been reiterated in recent years. This time the agenda’s object is not students perse, but nation-states. It is the nation that must become competitive and proﬁtable, and ifthis conception doesn’t specify which segments of society will contribute the most to—and
The Relationships Between Isokinetic Peak Torque and Cross-Sectional Area of the Forearm Flexors and Extensors

,. The purpose of this investigation was to use magnetic resonance imaging (MRI) to examine the relationships between the cross-sectional area (CSA) of the flexors and extensors of the forearm and isokinetic peak torque at speeds of contraction from zero to 300 deg/sec. Ten men (mean ± SO = 23.9 ± 4.5 years) volunteered as subjects for this study. Peak torque values for flexion and extension of the forearm were determined at 0, 60, 120, 180, 240, and 300 deg/sec using a Cybex II isokinetic dynamometer. For the forearm flexors, the only significant (p 0.05) correlations for the forearm extensors. It is likely that these findings were most influenced by the contribution of primarily fast-twitch fibers to peak torque at fast speeds of contraction and the differences in architecture (parallel versus pennate fiber orientation) of the forearm flexors versus extensor muscles.
Shared generation of authenticators and signatures

Often it is desired that the power to sign or authenticate messages is shared. This paper presents methods to collectively generate RSA signatures, provably secure authenticators and unconditionally secure authenticators. In the new schemes, l individuals are given shares such that k ≤ l are needed to generate a signature (authenticator) but less than k can not. When the k people have finished signing (authenticating), nobody can perform an impersonation or substitution attack. These schemes are called threshold signature (authentication) schemes. Clearly these schemes are better than each of the k individuals sending a separate authenticator for each message or if each of the k individuals each send their share to a “trusted” person who will sign for them.
"Emotions-Only" versus "Special People": Genre in fan discourse

This essay looks at genre as a complex set of discursive threads running unevenly through production, TV text, and fan reception. Through a case study of the reception of fan favorite Roswell , this essay interrogates the role of genre in spectatorship. In its mixing of teen and science fiction elements, Roswell trod upon contested generic spaces, eliciting strong reaction from its viewers. Connections between genre and gender came to the fore, as producer commentary linked science fiction with male audiences and teen romance with female audiences. Fans responded with analyses that greatly complicated and at times overtly rejected industrial suppositions regarding the gendered work of genre. Through these fan conversations, we can witness the complexity of genre as discursive thread moving through not only TV texts but also multivariant fan responses. I intend this essay to work at two levels. My analysis of fan responses to Roswell models the possibilities of a close study of genre discourse. At the same time, my case study probes the nature of genre in fan engagement, as genre discourses intersect with other fan concerns such as character identification, perceptions of textual quality, and questions of gender representation. While we cannot necessarily look to fan accounts for proof of how viewers engage with genre, they do tell us how fans frame their engagement with genre, how they incorporate genre into their performance of fannishness, and how they perform and thus enact genre itself as a shared cultural process.
DEFECTIVE CREATINE METABOLISM IN GYRATE ATROPHY OF THE CHOROID AND RETINA (GA)

GA patients exhibit chorioretinal degeneration and histologic muscle abnormalities. Owing to an inherited deficiency of ornithine aminotransferase, they accumulate ornithine to levels which are 10× normal and well above the Ki of glycine transamidinase, the first enzyme in the creatine biosynthetic pathway. Previous work utilizing an insensitive assay has shown reduced levels of the creatine (cr) presursor guanidinoacetic acid (gaa) in the urine of patients with GA (Sipila et al, J.Clin.Invest. 67: 1805,1981). We developed a specific HPLC/fluorometric method for measuring these compounds in biologic samples. The lower limit of detectability for cr is 0.1 pmol and for gaa 3 pmol. We found subnormal levels of both cr and gaa in patients with GA. In addition, we found reduced levels of total cr in adult GA skeletal muscle: patients (n=3) mean (range) is 6.5 nmol/mg prot (5.1-7.8); control (n=3) 31.4 (23.5-42.0). We conclude from the reduced levels of gaa that cr synthesis is impaired in GA and that this eventually leads to reduction of tissue levels of cr despite normal dietary intake. These results support the hypothesis that cr deficiency is an important pathophysiologic factor in GA.
Induction of fibroblast proliferation by human mononuclear leukocyte‐derived proteins

Human peripheral blood mononuclear leukocytes stimulated by T cell antigen or mitogen release soluble factors that induce mitogenesis of dermal fibroblasts in vitro. Fractionation of supernatants from antigen-stimulated mononuclear leukocyte cultures by Sephadex G-100 yielded 2 major peaks of fibroblast proliferation activity (approximately 60,000 and approximately 16,000 MW). Both proliferation factors are heat stable (56 degrees C for 45 minutes) proteins. These data show that mononuclear leukocytes, under appropriate conditions, can release soluble mediators that can stimulate fibroblast proliferation; such leukocytes may also play a role in expanding fibroblast populations adjacent to certain cell-mediated immune reactions in vivo.
Proteasome substrate degradation requires association plus extended peptide

To determine the minimum requirements for substrate recognition and processing by proteasomes, the functional elements of a ubiquitin-independent degradation tag were dissected. The 37-residue C-terminus of ornithine decarboxylase (cODC) is a native degron, which also functions when appended to diverse proteins. Mutating the cysteine 441 residue within cODC impaired its proteasome association in the context of ornithine decarboxylase and prevented the turnover of GFP-cODC in yeast cells. Degradation of GFP-cODC with C441 mutations was restored by providing an alternate proteasome association element via fusion to the Rpn10 proteasome subunit. However, Rpn10-GFP was stable, unless extended by cODC or other peptides of similar size. In vitro reconstitution experiments confirmed the requirement for both proteasome tethering and a loosely structured region. Therefore, cODC and degradation tags in general must serve two functions: proteasome association and a site, consisting of an extended peptide region, used for initiating insertion into the protease.
A molecular dynamics study of small water clusters comparing two flexible models for water

We report results from a molecular dynamics study of small water clusters, (H2O)n=2,3,4,6,8, comparing the recent polarizable, dissociable (PD) model of Halley et al. with the central force Stillinger-Rahman (SR) model. Dynamics calculations in the microcanonical ensemble quantified short-time averaged temperatures and RMS bond length fluctuations, which, in combination with simulated thermal quenching, identified structures and structural and phase changes of the clusters. Both models generally pointed to similar global minimum energy configurations, but local minima configurations, relative energies, and RMS bond length fluctuations varied more significantly. The PD model, with its incorporation of many-body effects, more accurately reproduced the structural features of clusters predicted from ab initio calculations, although it over-estimated the binding energies. Solid-like, pre-melting, and liquid-like states were identified based upon RMS bond length fluctuations for the O-O, O-H and H-H pairs. The SR and PD models yielded very similar trends in melting temperature as a function of cluster size. This suggests that general trends in the melting phenomenon do not depend strongly upon details of the models. The melting temperatures for the dimer and tetramer closely resembled the bulk melting temperature, while those for other sizes were considerably lower.
Auto-ionization of positrons in heavy ion collisions

Autoionization of positrons occurs as a fundamentally new process of quantum electrodynamics, if empty 1s- or 2p 1/2− etc. electronic shells obtain binding energies larger than 2m e c 2. This effect should be experimentally observable in the scattering of very heavy ions (Z≧80) on each other since in such collisions superheavy electronic molecules are formed (superheavy quasi-molecules). The scattering mechanism and the distribution of autoionization positrons are discussed. The adiabaticity of the heavy ion collision is studied and the electron-positron pair production background to the ionization problem is estimated. Analytic solutions are obtained for 1/r-potentials for the caseZα≧1. The phase shifts of negative energy solutions in the case of cutoff Coulomb potentials reveal the accuracy of the autoionization formalism.
Expansion formulas. I. A general method

Abstract Using the MacMahon Master Theorem, Carlitz, in (SIAM J. Appl. Math. 26 (1974), 431–436; 8 (1977), 320–336) obtains the expansion ∑ n i ⩾ 0 ( n i + b 1 ) n1 … ( n s + b s ) n s (u 1 n i … u s n s (n 1 ! … n s !) = e b 1 x 1 + ⋯ b s x s det (δ ij − x i a ij ), where for j = 1, 2,…, s, -n j = ∑ i = 1 s n i a ij and for i = 1, 2,…, s, u i = x i exp (−∑ j = 1 s a ij x j ) . A “factorial” analog of this expansion and other related results are also given. In this paper we derive one general formula from which these expanions follow as special cases. This formula demonstrates a bijection between a class of expansion formulas and Sheffer sequences of polynomials.
Pathology of the heart in acromegaly: anatomic findings in 27 autopsied patients

Abstract The morphologic characteristics and pathogenesis of cardiac enlargement in acromegaly remain poorly understood, partly because of the paucity of detailed anatomic studies. Autopsy was performed on 41 acromegalic patients at Mayo in the 60-year period 1919 to 1978, of which 27 cases with adequate clinical data and tissue were included in this pathologic review of the heart in acromegaly. Cardiomegaly was common (22 of 27 cases, or 81%), and occurred in both hypertensive and nonhypertensive patients. The mean heart weight (618 g.) of 16 patients who died 10 or more years after the clinical onset of acromegaly was significantly higher (p
Multiple steady states in combined buoyancy and wind driven natural ventilation : The conditions for multiple solutions and the critical point for initial conditions

Abstract Natural ventilation systems may have multiple steady states in the combined buoyancy and wind driven mode in a single space. In this paper, dynamical system analysis is applied both graphically and quantitatively to investigate the multiple steady state behavior of such a natural ventilation system. The necessary conditions for the system to have multiple steady states are derived for a single space combined wind and buoyancy driven natural ventilation system. Distinct from previous studies, the derivation comes from the transient dynamical system behaviors of the system rather than from the steady state equations, and it can be applied to more general cases. Based on the dynamical system analysis, the quantitative relation between the initial temperature and the final steady state is investigated for the single space case. The unstable steady state, which cannot physically exist in reality, is the critical point of the initial value in determining the final (steady) state of the system.
Effect of high energy electron radiation on MIPB-impregnated polypropylene film

The effect of impregnating capacitor-grade polypropylene film with an aromatic hydrocarbon fluid is examined with a view towards assessing the response under radiation of the relevant properties of the film. Monoisopropyl biphenyl (MIPB)-impregnated polypropylene film was exposed in air to 1-MeV electrons at different dose rates and the post-radiation effects on the electrical, mechanical, morphological, and chemical properties were evaluated. The results obtained indicate that the oil-impregnated films remain relatively stable even at the highest dose of 10/sup 8/ rads. This is in contrast to the results reported by the authors (ibid., vol.NS-34, no.6, p.1822-6, 1987) for dry polypropylene films which underwent degradation due to chain scission and oxidation. In the present instance, it is believed that impregnation of the film has inhibited the diffusion of oxygen and consequently favored crosslinking. The chemical characterizations as well as the changes in some of the measured properties of the film are seen to corroborate this belief. >
Estimates of sulfate aerosol wet scavenging coefficient for locations in the Eastern United States

Abstract Scavenging of atmospheric aerosols by falling precipitation is a major removal mechanism for airborne particles. The process can be described by a wet scavenging coefficient (WSC), denoted L , that is dependent on the rainfall rate, R , and the collision efficiency between raindrops and aerosol particles, E . We report bulk average L values for location in the Eastern United States, estimated based on sulfate mass balance in the atmospheric domain of interest. Data used are taken from several observational networks: (a) the Atmospheric Integrated Research Monitoring Network (AIRMoN) which is part of the National Atmospheric Deposition Program/National Trends Network (NADP/NTN); (b) the Interagency Monitoring of Protected Visibility Environments (IMPROVE); and (c) the National Climatic Data Center (NCDC). The results are fitted relatively well by L values computed using a microphysical representation of the WSC process based on collision efficiency and precipitation size distribution. Such representation leads to a simple expression L = f ( R ) for soluble aerosols, suitable for WSC description in regional scale models. The agreement between the bulk method and the microphysical representation is due in part to the predominant widespread precipitation, well represented by Marshall and Palmer raindrop distribution, and in part due to assumptions made in the bulk model. Results indicate that high-resolution rainfall rates and realistic vertical cloud structure information are needed to improve the accuracy of aerosol wet scavenging modeling for pollution studies.
CHEMICAL TREATMENTS OF COTTAGE CHEESE WHEY TO REDUCE FOULING OF ULTRAFILTRATION MEMBRANES

Increases in ultrafiltration rates were obtained by treating whey with acid, calcium-sequestering agents, or compounds to modify specific protein side chains, or by increasing the ionic strength. The proteins in whey, examined by scanning electron microscopy, underwent marked structural changes corresponding to these changes in the chemical environment. Depending upon the treatment, membrane fouling deposits showed strands, lattice networks, beaded matrixes, helical structures, or protein sheets of varying thickness. The protein forms were affected by the pH, the quantity of reagent added, and the protein functional group which was modified. Fouling of membranes was reduced when formation of protein sheets over the membrane was retarded.
Variable Response to a Long-Acting Agonist of Luteinizing Hormone-Releasing Hormone in Girls with McCune-Albright Syndrome

Abstract Six girls with McCune-Albright syndrome were treated for at least 2 months with the long-acting LHRH agonist D-Trp6-Pro9-NEt-LHRH, which previously was found to be an effective treatment for true precocious puberty. Nocturnal and LHRH-stimulated serum gonadotropin levels and plasma estradiol levels were measured before treatment and after 2–3 months of treatment. Five of the six girls had no decrease in serum gonadotropin or plasma estradiol levels during therapy, and their pubertal signs were unaffected by treatment. All five of these girls had serum gonadotropin levels that were within or below the normal prepubertal range. The sixth girl, who had gonadotropin levels in the normal pubertal range before treatment, had decreased serum gonadotropin and plasma estradiol levels during 1 yr of LHRH analog therapy. This was associated with cessation of menses and regression of secondary sexual changes. The failure of LHRH analog to modify the course of precocious puberty in the five patients with prep...
Applications of laser-induced breakdown spectroscopy for geochemical and environmental analysis: A comprehensive review

Abstract Applications of laser-induced breakdown spectroscopy (LIBS) have been growing rapidly and continue to be extended to a broad range of materials. This paper reviews recent application of LIBS for the analysis of geological and environmental materials, here termed "GEOLIBS" . Following a summary of fundamentals of the LIBS analytical technique and its potential for chemical analysis in real time, the history of the application of LIBS to the analysis of natural fluids, minerals, rocks, soils, sediments, and other natural materials is described.
Digital Mammography: ROC Studies of the Effects of Pixel Size and Unsharp-Mask Filtering on the Detection of Subtle Microcalcifications

We investigated the spatial resolution requirement and the effect of unsharp-mask filtering on the detectability of subtle microcalcifications in digital mammography. Digital images were obtained by digitizing conventional screen-film mammograms with a 0.1 X 0.1 mm2 pixel size, processed with unsharp masking, and then reconstituted on film with a Fuji image processing/simulation system (Fuji Photo Film Co., Tokyo, Japan). Twenty normal cases and 12 cases with subtle microcalcifications were included. Observer performance experiments were conducted to assess the detectability of subtle microcalcifications in the conventional, the unprocessed digital, and the unsharp-masked mammograms. The observer response data were evaluated using receiver operating characteristic (ROC) and LROC (ROC with localization) analyses. Our results indicate that digital mammograms obtained with 0.1 X 0.1 mm2 pixels provide lower detectability than the conventional screen-film mammograms. The detectability of microcalcifications in the digital mammograms is improved by unsharp-mask filtering; the processed mammograms still provide lower accuracy than the conventional mammograms, however, chiefly because of increased false-positive detection rates for the processed images at each subjective confidence level. Viewing unprocessed digital and unsharp-masked images in pairs resulted in approximately the same detectability as that obtained with the unsharp-masked images alone. However, this result may be influenced by the fact that the same limited viewing time was necessarily divided between the two images.
Growth Factor Regulation of Prostaglandin-Endoperoxide Synthase 2 (Ptgs2) Expression in Colonic Mesenchymal Stem Cells

We previously found that a population of colonic stromal cells that constitutively express high levels of prostaglandin-endoperoxide synthase 2 (Ptgs2, also known as Cox-2) altered their location in the lamina propria in response to injury in a Myd88-dependent manner (Brown, S. L., Riehl, T. E., Walker, M. R., Geske, M. J., Doherty, J. M., Stenson, W. F., and Stappenbeck, T. S. (2007) J. Clin. Invest. 117, 258–269). At the time of this study, the identity of these cells and the mechanism by which they expressed high levels of Ptgs2 were unknown. Here we found that these colonic stromal cells were mesenchymal stem cells (MSCs). These colonic MSCs expressed high Ptgs2 levels not through interaction with bacterial products but instead as a consequence of mRNA stabilization downstream of Fgf9 (fibroblast growth factor 9), a growth factor that is constitutively expressed by the intestinal epithelium. This stabilization was mediated partially through a mechanism involving endogenous CUG-binding protein 2 (CUGbp2). These studies suggest that Fgf9 is an important factor in the regulation of Ptgs2 in colonic MSCs and may be a factor involved in its constitutive expression in vivo.
APS study of directed energy weapons

Before being considered seriously for defense against potential ballistic missile attacks, all existing candidates for directed energy weapons (DEW) require improvement by a factor of at least 100 in power output and beam quality, according to an American Physical Society (APS) report released April 23.
Proposed cooperative model of dissociative chemisorption

Abstract A model for the sharp temperature dependence of the dissociation probability of physisorbed diatomic molecules is proposed and discussed. The central feature of the model is the cooperative rearrangement of the substrate atoms upon dissociation of the adsorbates. This reconstruction of the surface and the low value of the probability of dissociation of a single molecule on an otherwise clean surface are both necessary to insure a sharp transition from physisorbed molecules to chemisorbed atoms.
Coulometric Titration of Free Cyanide with Electrogenerated Hypobromite

Abstract A rapid and sensitive method is described for the direct determination of cyanide by coulometric titration with electrogenerated hypobromite. A biamperometric end point was utilized. From 0.498 – 9.980 ueq of cyanide were analyzed with an average error of 0.36% and an average standard deviation of 0.045.
Semiconductor detector telescopes for measuring proton energies up to 300 MeV — problems and solutions

Abstract The major problem in measuring the energy of a medium energy particle in a semiconductor (or scintillation) detector is the high probability that it will experience a nuclear reaction or scattering in the detector material, before it goes through its range and stops. This problem can be solved by dividing the stopping detector into a number of laminae, measuring the pulse height produced by each lamina, and comparing with predictions obtained from integrations of the range-energy relation. We will present results obtained in using such a technique with 45 MeV protons, and considerations involved in extending the technique to 300 MeV protons.
The mechanical considerations of magnetic recording heads

The paper is confined to a discussion of the mechanical limits imposed on magnetic recording heads by the required performance specification. The performance criteria of a multi-track head are normally: sensitivity and the variation in sensitivity between tracks, the short wavelength response, high-frequency losses, bias sensitivity, and cross-talk between adjacent tracks. The manufacturing problems associated with multi-track heads are discussed in relation to the effects of mechanical variations on the head performance.
Whole Genome Amplification of Plasma-Circulating DNA Enables Expanded Screening for Allelic Imbalance in Plasma

Apoptotic and necrotic tumor cells release DNA into plasma, providing an accessible tumor biomarker. Tumor-released plasma-circulating DNA can be screened for tumor-specific genetic changes, including mutation, methylation, or allelic imbalance. However, technical problems relating to the quantity and quality of DNA collected from plasma hinder downstream genetic screening and reduce biomarker detection sensitivity. Here, we present a new methodology, blunt-end ligation-mediated whole genome amplification (BL-WGA), that efficiently amplifies small apoptotic fragments ( 5 kb) and enables reliable high-throughput analysis of plasma-circulating DNA. In a single-tube reaction, purified double-stranded DNA was blunted with T4 DNA polymerase, self-ligated or cross-ligated with T4 DNA ligase and amplified via random primer-initiated multiple displacement amplification. Using plasma DNA from breast cancer patients and normal controls, we demonstrate that BL-WGA amplified the plasma-circulating genome by ∼1000-fold. Of 25 informative polymorphic sites screened via polymerase chain reaction-denaturating high-performance liquid chromatography, 24 (95%) were correctly determined by BL-WGA to be allelic retention or imbalance compared to 44% by multiple displacement amplification. By enabling target magnification and application of high-throughput genome analysis, BL-WGA improves sensitivity for detection of circulating tumor-specific biomarkers from bodily fluids or for recovery of nucleic acids from suboptimally stored specimens.
4 Pre-operative cardiac evaluation before non-cardiac surgery

Several recent guidelines have been published to codify the pre-operative evaluation of the cardiac patient undergoing non-cardiac surgery. Considering the lack of any randomized clinical trials in this area, they have incorporated information from both prospective cohort studies and the experience from the general care of the cardiac patient. The decision to perform testing is based on the clinical risk factors, exercise tolerance and surgical procedure. Testing should not be performed unless the results will actually change practice. Among the interventions advocated to reduce peri-operative risk, the decision to perform coronary revascularization before non-cardiac surgery must include issues related to local rates of morbidity and mortality for each of the procedures and potential long-term benefits.