cssi/SciSciGPT-SciSciNet huggingface dataset:
Cohort profile: the Buffalo OsteoPerio microbiome prospective cohort study.

Purpose The Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) study is a prospective cohort study focused on the relationship between the microbiome and oral and systemic health outcomes in postmenopausal women. The cohort was established to examine how the oral microbiome is affected by (and how it affects) periodontal disease presence, severity and progression and to characterise the relationship between the microbiome, lifestyle habits and systemic disease outcomes. Participants Participants (n=1342) were postmenopausal women who were participating in the Women’s Health Initiative observational study at the Buffalo, New York clinical centre. There were 1026 participants at the 5-year follow-up visit and 518 at the 15-year visit. Findings to date Data collected include questionnaires, anthropometric measures, serum blood and saliva samples. At each clinic visit, participants completed a comprehensive oral examination to measure oral health and the oral microbiome. Preliminary findings have contributed to our understanding of risk factors for periodontal disease and the relationship between the oral microbiome and periodontal disease. Future plans The novel microbiome data collected on a large sample of participants at three time points will be used to answer a variety of research questions focused on temporal changes in the microbiome and the relationship between the oral microbiome and oral and systemic disease outcomes. Little is currently known about the relationship between the oral microbiome and health outcomes in older adults; data from the OsteoPerio cohort will fill this gap. Microbiome samples are currently being analysed using next-generation sequencing technology with an anticipated completion date of late 2018.
A Resurgence in Neuromorphic Architectures Enabling Remote Sensing Computation

Technological advances have enabled exponential growth in both sensor data collection, as well as computational processing. However, as a limiting factor, the transmission bandwidth in between a space-based sensor and a ground station processing center has not seen the same growth. A resolution to this bandwidth limitation is to move the processing to the sensor, but doing so faces size, weight, and power operational constraints. Different physical constraints on processor manufacturing are spurring a resurgence in neuromorphic approaches amenable to the space-based operational environment. Here we describe historical trends in computer architecture and the implications for neuromorphic computing, as well as give an overview of how remote sensing applications may be impacted by this emerging direction for computing.
Regulation of hepatic glutamine metabolism by miR-122.

Abstract Objective It is well established that the liver-specific miR-122, a bona fide tumor suppressor, plays a critical role in lipid homeostasis. However, its role, if any, in amino acid metabolism has not been explored. Since glutamine (Gln) is a critical energy and anaplerotic source for mammalian cells, we assessed Gln metabolism in control wild type (WT) mice and miR-122 knockout (KO) mice by stable isotope resolved metabolomics (SIRM) studies. Methods Six-to eight-week-old WT and KO mice and 12- to 15-month-old liver tumor-bearing mice were injected with [U–13C5,15N2]-L-Gln, and polar metabolites from the liver tissues were analyzed by nuclear magnetic resonance (NMR) imaging and ion chromatography-mass spectrometry (IC-MS). Gln-metabolism was also assessed in a Gln-dependent hepatocellular carcinoma (HCC) cell line (EC4). Expressions of glutaminases (Gls and Gls2) were analyzed in mouse livers and human primary HCC samples. Results The results showed that loss of miR-122 promoted glutaminolysis but suppressed gluconeogenesis in mouse livers as evident from the buildup of 13C- and/or 15N-Glu and decrease in glucose-6-phosphate (G6P) levels, respectively, in KO livers. Enhanced glutaminolysis is consistent with the upregulation of expressions of Gls (kidney-type glutaminase) and Slc1a5, a neutral amino acid transporter in KO livers. Both Gls and Slc1a5 were confirmed as direct miR-122 targets by the respective 3′-UTR-driven luciferase assays. Importantly, expressions of Gls and Slc1a5 as well as glutaminase activity were suppressed in a Gln-dependent HCC (EC4) cell line transfected with miR-122 mimic that resulted in decreased 13C-Gln, 13C-a-ketoglutarate, 13C-isocitrate, and 13C-citrate levels. In contrast, 13C-phosphoenolpyruvate and 13C-G6P levels were elevated in cells expressing ectopic miR-122, suggesting enhanced gluconeogenesis. Finally, The Cancer Genome Atlas—Liver Hepatocellular Carcinoma (TCGA-LIHC) database analysis showed that expression of GLS is negatively correlated with miR-122 in primary human HCCs, and the upregulation of GLS RNA is associated with higher tumor grade. More importantly, patients with higher expressions of GLS or SLC1A5 in tumors exhibited poor survival compared with those expressing lower levels of these proteins. Conclusions Collectively, these results show that miR-122 modulates Gln metabolism both in vitro and in vivo, implicating the therapeutic potential of miR-122 in HCCs that exhibit relatively high GLS levels.
Competitive ecosystems are robustly stabilized by structured environments

Natural environments, like soils or the mammalian gut, frequently contain microbial consortia competing within a niche, wherein many species contain genetic mechanisms of interspecies competition. Recent computational work suggests that physical structures in the environment can stabilize competition between species that would otherwise be subject to competitive exclusion under isotropic conditions. Here we employ Lotka-Volterra models to show that physical structure stabilizes large competitive ecological networks, even with significant differences in the strength of competitive interactions between species. We show that for stable communities the length-scale of physical structure inversely correlates with the width of the distribution of competitive fitness, such that physical environments with finer structure can sustain a broader spectrum of interspecific competition. These results highlight the generic stabilizing effects of physical structure on microbial communities and lay groundwork for engineering structures that stabilize and/or select for diverse communities of ecological, medical, or industrial utility. AUTHOR SUMMARYNatural environments often have many species competing for the same resources and frequently one species will out-compete others. This poses the fundamental question of how a diverse array of species can coexist in a resource limited environment. Among other mechanisms, previous studies examined how interactions between species - like cooperation or predation - could lead to stable biodiversity. In this work we looked at this question from a different angle: we used computational models to examine the role that the environment itself might play in stabilizing competing species. We modeled how species arrange themselves in space when the environment contains objects that alter the interfaces along which competing species meet. We found that these structured environments stabilize species coexistence, across a range of density of those objects and in a way that was robust to differing strengths of interspecies competition. Thus, in addition to biological factors, our work presents a generic mechanism by which the environment itself can influence ecological outcomes and biodiversity.
Optical absorption and fluorescence intensities of Nd 3 + in the garnets Ca Y 2 Mg 2 Ge 3 O 12 and Gd 3 Ga 5 O 12 and the biaxial crystal La 2 Be 2 O 5

The Judd-Ofelt (JO) theory was applied to interpret the optical-absorption intensities of trivalent neodymium (${\mathrm{Nd}}^{3+}$) in the garnets Ca${\mathrm{Y}}_{2}$${\mathrm{Mg}}_{2}$${\mathrm{Ge}}_{3}$${\mathrm{O}}_{12}$ and ${\mathrm{Gd}}_{3}$${\mathrm{Ga}}_{5}$${\mathrm{O}}_{12}$ and the biaxial crystal ${\mathrm{La}}_{2}$${\mathrm{Be}}_{2}$${\mathrm{O}}_{5}$ yielding the JO parameters ${\ensuremath{\Omega}}_{2}$, ${\ensuremath{\Omega}}_{4}$, and ${\ensuremath{\Omega}}_{6}$. The JO theory applied to the $^{4}F_{\frac{3}{2}}$ fluorescence transition in ${\mathrm{Nd}}^{3+}$ predicts a linear relation between the ratio $R$ of the 1.06- to 1.35-\ensuremath{\mu}m fluorescence band intensities and the ratio $\frac{{\ensuremath{\Omega}}_{4}}{{\ensuremath{\Omega}}_{6}}$ of JO intensity parameters. This linearity was verified by independent measurements of $R$ and $\frac{{\ensuremath{\Omega}}_{4}}{{\ensuremath{\Omega}}_{6}}$ for a series of ${\mathrm{Nd}}^{3+}$-doped crystals and was found to be dependent on the type of free-ion wave functions that were used in calculating the required transition-matrix elements.
Food and Drug Administration Safety Communication on the Use of Transvaginal Mesh in Pelvic Organ Prolapse Repair Surgery: The Impact of Social Determinants of Health.

Objective This study was to examine the impact of the July 2011 Food and Drug Administration (FDA) safety communication on the use of transvaginal mesh in pelvic organ prolapse (POP) repair by patients' race and ethnicity. Methods We conducted an observational cohort study of women undergoing POP repairs in 2008 to 2015 in New York State. We examined the changes in transvaginal mesh use in POP repairs before and after the FDA communication by patients' race and ethnicity. Piecewise logistic regression models were used to assess the trends of mesh use, adjusting for patient characteristics. We performed a subgroup analysis of the trends of transvaginal mesh use by racial groups, stratifying by patients' neighborhood socioeconomic status. Results We included 49,848 women (78% white, 7% black, and 15% Hispanic) with an average ± SD age of 60.2 ± 13.0 years. After the safety communication, the use of transvaginal mesh in POP repairs decreased among white women (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.41-0.50) and African Americans (OR, 0.48; 95% CI, 0.35-0.67) but remained stable among Hispanic women (OR, 0.88; 95% CI, 0.70-1.11). Only in the subgroup of patients from high-income areas, there was a trend toward decreasing mesh use among Hispanic patients after 2011 (OR, 0.71; 95% CI, 0.49-1.04). Conclusions The communications related to the safety of transvaginal mesh did not have an equal impact across racial groups. Mesh use decreased among white and African American women but not among Hispanic women after the 2011 FDA safety communication. Particular attention is warranted for patients from disadvantaged groups, especially low-income minorities, when disseminating medical device safety messages.
I Am This Widow: Social Support in Friendship After the Loss of a Spouse in Mid-Life.

This paper elaborates on relational processes of social support after widowhood in mid-life. It extends knowledge in effective support by examining themes of friendship communication between widows...
Censored patients in Kaplan–Meier plots of cancer drugs: An empirical analysis of data sharing

Abstract Introduction Kaplan–Meier survival analysis, the cornerstone of evaluating efficacy of oncology drugs in randomised controlled trials (RCTs), assumes censored patients are neither healthier nor sicker than those followed. We sought to examine whether censoring patterns differ between the control and experimental arms in one oncology journal that mandates the reporting of the number of patients censored. Methods In this retrospective review, proportion of censoring and study design data were gathered from RCTs published in The Lancet Oncology that reported Kaplan–Meier curves between May 2018 and August 2019. Differential censoring rates were analysed at the 1st, 3rd, 6th, and overall time points in each study. Analysis was stratified by curves reporting progression-free survival (PFS) or overall survival (OS) end-points. Results Of the 160 articles reviewed, 29 studies with 51 Kaplan–Meier curves were eligible. In both OS (N = 25) and PFS curves (N = 26), the absolute weighted difference in censoring between the control and experimental arms was initially positive, indicating more censoring in the control arm (first time point OS: 0.32%; PFS: 2.00%). The absolute difference then became negative, indicating more censoring in the experimental arm as time progressed (end-of-study OS: −7.54%; PFS: −9.09%). Conclusion Differences in censoring between control and experimental arms of cancer RCTs suggest that there could be systematic bias present at various study time points that may influence key results. Further investigation is needed, as possible reasons include study assignment disappointment, inappropriate follow-up length, lack of efficacy, or intolerable toxicity, each predominant at specific time points after randomisation.
Xenopus models suggest convergence of gene signatures on neurogenesis in autism.

Willsey et al. dissect phenotypes associated with in vivo disruption of ten ASD-associated genes using a hypothesis-free, parallelized approach in Xenopus tropicalis. These studies continue to implicate cortical neurons in ASD pathogenesis and suggest a convergence on functions related to neurogenesis.
Multiprocessing Systems

This paper surveys the state of the art in the design and evaluation of multiprocessing systems. Multiprocessor architectures of the SIMD and MIMD type are reviewed and further classified depending on their tight or loose coupling and their homogeneity. The additional complexity of the software for control, synchronization, efficient utilization, and performance monitoring of multiple processors is emphasized.
A Guide to Posting and Managing Preprints

Posting preprints online allows psychological scientists to get feedback, speed dissemination, and ensure public access to their work. This guide is designed to help psychological scientists post p...
Controlled snapping sequence and energy absorption in multistable mechanical metamaterial cylinders

Abstract Mechancial metamaterials comprising bistable unit cells utilize a sinusoidal beam to enable significant deformation between stable states, which is associated with energy absorption. A stack of similar bistable unit cells, i.e., multistable metamaterials, will snap to a second stable state in a seemingly random sequence that is influenced by minute variations in manufacturing. However, it is desirable to tailor the energy absorbed and the snapping sequence to obtain predictable geometric reconfiguration in multistable cylindrical metamaterials. Additive Manufacturing (AM) processes, such as Fused Deposition Modeling (FDM), are able to produce these structures with flexible filaments, such as Thermoplastic Polyurethane (TPU), to enable flexible, multistable cylindrical structures. In this study, we investigated experimentally and computationally the mechanical behavior and controlled snapping sequence of bistable lattices incorporated into cylindrical shells. Individual layers are printed using FDM and assembled into a cylinder. Experimental and computational results for uniaxial tension and compression tests, applied along the length of the cylinder, are used to evaluate the non-linear mechanical behavior and quantify energy absorption of the system during both loading (tension) and unloading (compression). It was shown that energy absorption during loading was always greater than unloading and increased with an increasing number of layers. The energy absorbed by individual layer was approximately 1.25 J in loading and 0.52 J in unloading for a layer with sinusoidal beam thickness of 1.5 mm. The direction dependence of the energy absorption is attributed to the printed configuration of the lattices. Individual layers can be stacked to tailor the amount of energy absorption. In addition, the energy absorbed and the snapping sequence of the multistable cylinder could be controlled by changing the thickness of the sinusoidal beams in each layer. The variation of energy absorbed is strongly influenced by the thickness of the sinusoidal beam. By increasing the beam thickness from 1 mm to 2 mm, energy absorption increased by approximately a factor of three. Beam thickness accurately controlled the snap-through behavior in experimental samples, but the computational model experienced re-distribution of strain and snap-close forces that cause less predictable snap-through behavior in unloading (compression). The design, analysis and control of snapping sequence of cylindrical shells with multistable states provides new opportunities in practical application of control of elastic waves, energy absorption and reconfigurable structures.
N-polar ScAlN and HEMTs grown by molecular beam epitaxy

Molecular beam epitaxy of single-phase wurtzite N-polar ScxAl1−xN (x ∼ 0.11–0.38) has been demonstrated on sapphire substrates by locking its lattice-polarity to the underlying N-polar GaN buffer. Coherent growth of lattice-matched Sc0.18Al0.82N on GaN has been confirmed by x-ray diffraction reciprocal space mapping of the asymmetric (105) plane, whereas lattice-mismatched, fully relaxed Sc0.11Al0.89N and Sc0.30Al0.70N epilayers exhibit a crack-free surface. The on-axis N-polar crystallographic orientation is unambiguously confirmed by wet chemical etching. High electron mobility transistors using N-polar Sc0.18Al0.82N as a barrier have been grown on sapphire substrates, which present the existence of well confined two-dimensional electron gas. A Hall mobility of ∼564 cm2/V s is measured for a 15-nm-thick Sc0.18Al0.82N barrier sample with a sheet electron concentration of 4.1 × 1013 cm−2, and the corresponding sheet resistance is as low as 271 Ω/sq. The polarity-controlled epitaxy of ScxAl1−xN provides promising opportunities for applications in high-frequency and high-power electronic and ferroelectric devices.
Conformational and geometrical properties of β-sheets in proteins

Abstract The present work treats the geometry of idealized, twisted parallel β-sheets and compares their local and long-range conformational properties to structures known from protein crystallography. Idealized model structures were generated by a least-squares search procedure designed to maximize interchain hydrogen-bond interactions between polypeptide chains of standard geometry whose degrees of freedom were restricted to systematic variations in the backbone torsional angles φ and ψ. Two continuously defined sets of regular, twisted, double-stranded conformations, corresponding to structures composed of either straight-helical or coiled-coil polypeptide chains, were investigated both with respect to quality of interchain hydrogen bonding and extensibility into multiply stranded structures. In either case, the introduction of increasing twist into the structure is accompanied by some degree of hydrogen bond distortion that ultimately restricts the extent of twist that may be accommodated in the sheet. The long-range geometrical configurations of twisted sheets are shown to primarily reflect an equilibrium between the forces that cause the individual polypeptide chains to twist in order to minimize their local conformational potential energies, and the requirements for interchain hydrogen bonding, which generally tend to resist the introduction of twist into the sheet. These effects manifest themselves differently, depending on the adjacent chain hydrogen-bonded connectivity in the sheet, and so account for the differences in the spatial configurations attained by rectangular plan sheets and β-barrel forming, rhombic plan sheets. Comparison of observed β-structures with idealized model structures shows that, to the extent that the observed structures are regularly hydrogen bonded, they are closely approximated by the models, average α-carbon superposition errors between model and observed structures for the cases examined typically being less than 0.8 A. This is the first in a series of three papers describing the structural properties of β-sheets in proteins.
The development of lactate and malate dehydrogenases in the C57BL-6 mouse kidney.

Abstract The development of lactate dehydrogenase (LDH; EC 1.1.1.27) and malate dehydrogenase (MDH; EC 1.1.1.37) was measured in the kidney of male and female C57BL 6 mice from ages prenatal 16 days to 80 days. Maximum reactions rates of the enzymes were measured in vitro by following the reduction of the nicotinamide-adenine dinucleotide spectrophotometrically. Analysis of variance showed no significant sex difference for LDH and MDH. There was a significant sex difference for the ratio LDH:MDH and a significant age difference for LDH, MDH, and the ratio LDH:MDH. In the male and female, LDH activity increased from prenatal 16 days to 30 days. Malate dehydrogenase activity reached adult values at 22 days in the male and at 30 days in the female. The ratio LDH:MDH in the male decreased from prenatal 16 days to 3 days, after which the ratio continued to decline to 20 days at a less rapid rate. This general pattern was also found in the female followed by a further decline in the ratio at 50 days. The development of LDH and MDH in the C57BL 6 mouse is tissue specific and probably parallels the development of the tissue's function. In the case of the kidney, LDH and MDH development may reflect maturation of mitochondrial function and the kidney's ability to concentrate urine.
Economic planning for market economies: The optimality of planning in an economy with uncertainty and asymmetrical information

Abstract The paper is based on a disequilibrium model which is Keynesian in the ‘short run’, ie with given expectations, but which admits of a continuum of equilibria when expectations are rational. Expectations are adaptive (so that they are rational only in the long run) but can be influenced by an indicative plan. The government and the private sector have differing information sets, each knowing some things the other sector does not (spontaneously) know. It is shown that in this world, an optimal plan dominates a self-fulfilling plan, which in turn dominates a no-planning equilibrium.
Studies on sex conversion in male Vitis vinifera L. ( sylvestris )

The appearance of functionally hermaphroditic flowers and mature seeded berries on otherwise male vines was defined as a natural sex conversion from functionally male to functionally hermaphroditic flowers. Sex conversion was investigated in vegetatively propagated vines of the wild male V. vinifera clone 030-44 derived from a seed sample collected in Iran. Frequency of sex conversion varied markedly among inflorescences on the same vine, among vines side by side, and from season to season, which implicated the effect of environment, both local and seasonal. Studies on vegetative selection for high fruitfulness revealed that sex conversion was not due to somatic mutation or any vegetative syndrome within the vine.
A Human Dendritic Cell Subset Receptive to the Venezuelan Equine Encephalitis Virus-Derived Replicon Particle Constitutively Expresses IL-32

Dendritic cells (DCs) are a diverse population with the capacity to respond to a variety of pathogens. Because of their critical role in pathogenesis and Ag-specific adaptive immune responses, DCs are the focus of extensive study and incorporation into a variety of immunotherapeutic strategies. The diversity of DC subsets imposes a substantial challenge to the successful development of DC-based therapies, requiring identification of the involved subset(s) and the potential roles each contributes to the immunologic responses. The recently developed and promising Venezuelan equine encephalitis replicon particle (VRP) vector system has conserved tropism for a subset of myeloid DCs. This immunotherapeutic vector permits in situ targeting of DCs; however, it targets a restricted subset of DCs, which are heretofore uncharacterized. Using a novel technique, we isolated VRP-receptive and -nonreceptive populations from human monocyte-derived DCs. Comparative gene expression analysis revealed significant differential gene expression, supporting the existence of two distinct DC populations. Further analysis identified constitutive expression of the proinflammatory cytokine IL-32 as a distinguishing characteristic of VRP-receptive DCs. IL-32 transcript was exclusively expressed (>50 fold) in the VRP-receptive DC population relative to the background level of expression in the nonreceptive population. The presence of IL-32 transcript was accompanied by protein expression. These data are the first to identify a subset of immature monocyte-derived DCs constitutively expressing IL-32 and they provide insights into both DC biology and potential mechanisms employed by this potent vector system.
The Use of Near-Infrared Cerebral Oximetry in Awake Carotid Endarterectomy

Abstract Study Objective: To determine the utility of cerebral oximetry for monitoring the adequacy of cerebral blood flow (CBF) during carotid cross-clamp. Design: Prospective study. Setting: University hospital. Patients: 16 consecutive ASA physical status III (or higher) patients for awake carotid endarterectomy (CEA). Interventions: Regional cerebral oxygen saturation (SaO 2 ) was monitored continuously during CEA, which was performed by the same surgeon, and with standard regional anesthetic, sedation, monitoring, and operative techniques. Data were recorded and analyzed using repeated measures analysis of variance (ANOVA). Measurements and Main Results: 14 hemodynamically stable patients demonstrated significant decreases in cerebral SaO 2 from baseline: 69 + 1.8% to 64 + 1.2% at carotid cross-clamp (p 2 was 63 + 1.4%, 64 + 1.5%, and 63 + 1.4%, respectively (p 2 rose significantly: 67 + 1.6% (p Conclusion: Cerebral SaO 2 decreased significantly on carotid cross-clamp in patients undergoing awake CEA. Hemodynamically stable patients demonstrated no evidence of regional brain failure when SaO 2 decreased to 63% (mean decrease of 7.2%). Two hemodynamically unstable patients had evidence of global brain failure when SaO 2 was less than 48% (mean decrease of 36%). Our findings suggest that cerebral oximetry reflects CBF, and it may be an effective, noninvasive method of monitoring regional cerebral oxygenation changes during CEA. Significant reductions in regional SaO 2 may be tolerated without evidence of brain failure. Further studies are needed to define an SaO 2 threshold that reflects regional brain failure.
A Review of “Everything Sings: Maps for a Narrative Atlas”

Astonishing. So much so that this review almost died aborning. Doing genuine justice to this slim but subversive and innovative volume would require a critique the length of a full Annals article a...
Homocysteine Induced Cerebrovascular Dysfunction: A Link to Alzheimer’s Disease Etiology

A high serum level of homocysteine, known as hyperhomocystenemia (HHcy) is associated with vascular dysfunction such as altered angiogenesis and increased membrane permeability. Epidemiological studies have found associations between HHcy and Alzheimer's disease (AD) progression that eventually leads to vascular dementia (VaD). VaD is the second most common cause of dementia in people older than 65, the first being AD. VaD affects the quality of life for those suffering by drastically decreasing their cognitive function. VaD, a cerebrovascular disease, generally occurs due to cerebral ischemic events from either decreased perfusion or hemorrhagic lesions. HHcy is associated with the hallmarks of dementia such as tau phosphorylation, Aβ aggregation, neurofibrillary tangle (NFT) formation, neuroinflammation, and neurodegeneration. Previous reports also suggest HHcy may promote AD like pathology by more than one mechanism, including cerebral microangiopathy, endothelial dysfunction, oxidative stress, neurotoxicity and apoptosis. Despite the corelations presented above, the question still exists - does homocysteine have a causal connection to AD? In this review, we highlight the role of HHcy in relation to AD by discussing its neurovascular effects and amelioration with dietary supplements. Moreover, we consider the studies using animal models to unravel the connection of Hcy to AD.
Relativistic impulse approximation for meson-nucleus scattering in the Kemmer-Duffin-Petiau formalism.

The first application of the Kemmer-Duffin-Petiau wave equation for spin-0 particles to meson-nucleus scattering is given. A relativistic impulse approximation using the Kemmer-Duffin-Petiau formalism is used to calculate meson-nucleus optical potentials. Comparison with the nonrelativistic impulse approximation is given.
Generation of configuration space obstacles: moving algebraic surfaces

We present an algebraic algorithm to generate the boundary of configuration space obstacles arising from the translatory motion of curved convex objects among curved convex obsta cles. Both the bou...
Anomalous optical behavior of biological media: modifying the optical window of myocardial tissues

In medical experimental and clinical treatment modalities of light, laser photocoagulation of ventricular tachycardia amongst others, the success of the application relies on whether or not the procedure operates in the optical window of the light-tissue interaction. The optical window of biological tissues can be determined by spectral scans of the optical properties. Optical anomalies may result from the irradiance, the wavelength, or from the tissue composition itself. The transmission of cw Nd:YAG laser light on myocardial tissue showed a nonlinearity in the transmission curve at approximately 3 kW/mm2 irradiance. The total attenuation coefficient dropped sharp from 1.03 plus or minus 0.04 mm-1 to 0.73 plus or minus 0.05 mm-1 at this point in the curve. On the other hand, aneurysm tissue has a highly organized fiber structure, which serves as light-guides, since the transmission of light along the length of the collagen fibers is approximately 50% higher than the transmission perpendicular to the fiber orientation. In addition, changes in optical properties due to tissue phase changes also influence the penetration depth. These phenomena can be utilized to manipulate the optical penetration to an advantage.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Superstrings in quantum cosmology.

We consider the dynamics of a four-dimensional universe using the pointlike field-theory effective action of superstrings. We use the boundary conditions of Hartle and Hawking and Vilenkin to solve the Wheeler-DeWitt equation. We find that under certain conditions the Universe will tunnel from a Euclidean regime to a Lorentzian regime. We study this process. We find that the inclusion of fermions (as extra internal degrees of freedom) due to supersymmetry can change the conclusion of Enqvist et al. where only bosonic fields were considered.
Antibiotic-Associated Diarrhea and Pseudomembranous Colitis: Are They Less Common with Poorly Absorbed Antimicrobials?

Diarrhea is a well-known complication of antibiotic therapy. Rates of antibiotic-associated diarrhea (AAD) vary from 5 to 25%. Some antibiotics are more likely to cause diarrhea than others, specifically, those that are broad spectrum and those that target anaerobic flora. This paper reviews the effects of antibiotics on the fecal flora as well as host factors which contribute to AAD. Clinical features and treatment of AAD are also described. Prevention of AAD rests on wise antibiotic policies, the use of probiotics and prevention of acquisition in the hospital setting. Data from clinical trials suggest that poorly absorbed antimicrobials might have a decreased risk of causing AAD and Clostridium difficile-associated disease, as concluded from studies of antibiotics used for preoperative bowel decontamination and poorly absorbed antibiotics used for traveler's diarrhea. Controlled trials would prove this but are not yet available. Probiotics may be a good adjunct to poorly absorbed antibiotics to minimize the risk of diarrhea associated with antibiotics.
Application of holography to real-time dynamic structural analysis of an advanced graphite-epoxy composite flight control component

Holographic Interferometry as been successfully employed to characterize the materials and behavior of diverse types of structures under stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the modal and mechanical behavior of aerodynamic control structures for advanced missiles systems has always required advanced instrumentation for data collection in either actual flight test or wind-tunnel simulations. Advanced optical holography techniques are alternate methods when define actual behavioral data on the ground in a nondestructive Hardware-in-the-loop environment. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced composite control structures and their integration with total vehicle system dynamics. Structures and materials can be analyzed with very low amplitude excitation and the resultant data can be used to adjust the accuracy of mathematically derived structural models. Holographic Interferometry offers a powerful tool to aid in the primary engineering and development of advanced graphite-epoxy fiber composite materials for use in advanced aerodynamic platforms. Aircraft, missile, and smart weapon control structure applications must consider environments where extremes in vibration and mechanical stresses can affect both operation and structural stability. These are ideal requisites for unlaces using advanced holographic methods in the initial design and subsequent test of such advanced components. Holographic techniques are nondestructive, real-time, and definitive in allowing the identification of vibrational modes, displacements, and motion geometries. Holographic analysis is also directly indicative of various types of induced mechanical, thermal, and acoustic structural stress related to hidden structural anomalies and defects. Deriving such information can be crucial to the determination of mechanical configurations and designs, as well as critical operational parameters of structures composed of advanced engineering materials.
Hepatic adaptations to sucrose and fructose

The liver is an important site of postprandial glucose disposal, accounting for the removal of up to 30% of an oral glucose load. The liver is also centrally involved in dietary lipid and amino acid uptake, and the presence of either or both of these nutrients can influence hepatic glucose uptake. The composition of ingested carbohydrate also influences hepatic glucose metabolism. For example, fructose can increase hepatic glucose uptake. In addition, fructose extraction by the liver is exceedingly high, approaching 50% to 70% of fructose delivery. The selective hepatic metabolism of fructose, and the ability of fructose to increase hepatic glucose uptake can, under appropriate conditions (eg, diets enriched in sucrose or fructose, high fructose concentrations), provoke major adaptations in hepatic metabolism. Potential adaptations that can arise in response to these conditions and putative mechanisms driving these adaptations are the subject of this review.
Quantitation of Asbestos Using Diffuse Reflection Infrared Spectroscopy

The use of diffuse reflection infrared spectroscopy for the quantitation of asbestos is investigated. The highly absorbing matrices that are typically present in an asbestos sample are addressed by the incorporation of an ashing technique that separates the asbestos from any cellulose matrix. The details for recovering microgram amounts of asbestos from the crucible after ashing are also described. About 0.01% by weight of amosite asbestos in cellulose can be detected. In addition, a curve-fitting program is used to assist in quantitation of two-component asbestos mixtures and in the quantitation of asbestos in the presence of china clay, a silicate commonly associated with asbestos insulation. The method shows that about 3 mu g of amosite can be detected in a matrix composed of four times this mass in chrysotile and four times in kaolin.
Early effects of intensive x-ray irradiation of the diencephalon in the rat.

Abstract Intensive X-ray irradiation, ranging from 20,000 r to 23,000 r from a 220 kv source, was directed at the diencephalon of adult, female rats. The most striking, early changes within the brains of 28 of 31 specimens were the formation of punctate hemorrhages and of perivascular globules throughout the lesion. The globules ranged from 0.5 μ to 20 μ in diameter and consisted of a glycoprotein. These changes were absent in adjacent, nonirradiated areas. The presence of extravasated erythrocytes and globules adjacent to intact neurons, including boutons terminaux, indicated a primary effect on the vessels. There was no selective damage to the neurosecretory cells. Most of the rats died within 3 weeks following the exposure. The hemopoietic tissue was unaffected as evidenced by a terminal, significant rise in the number of circulating neutrophiles and the absence of morphological alterations in the spleen.
Biochemical basis of the interaction between cystic fibrosis transmembrane conductance regulator and immunoglobulin-like repeats of filamin.

Mutations in the chloride channel cystic fibrosis transmembrane regulator (CFTR) cause cystic fibrosis, a genetic disorder characterized by defects in CFTR biosynthesis, localization to the cell surface, or activation by regulatory factors. It was discovered recently that surface localization of CFTR is stabilized by an interaction between the CFTR N terminus and the multidomain cytoskeletal protein filamin. The details of the CFTR-filamin interaction, however, are unclear. Using x-ray crystallography, we show how the CFTR N terminus binds to immunoglobulin-like repeat 21 of filamin A (FlnA-Ig21). CFTR binds to β-strands C and D of FlnA-Ig21 using backbone-backbone hydrogen bonds, a linchpin serine residue, and hydrophobic side-chain packing. We use NMR to determine that the CFTR N terminus also binds to several other immunoglobulin-like repeats from filamin A in vitro. Our structural data explain why the cystic fibrosis-causing S13F mutation disrupts CFTR-filamin interaction. We show that FlnA-Ig repeats transfected into cultured Calu-3 cells disrupt CFTR-filamin interaction and reduce surface levels of CFTR. Our findings suggest that filamin A stabilizes surface CFTR by anchoring it to the actin cytoskeleton through interactions with multiple filamin Ig repeats. Such an interaction mode may allow filamins to cluster multiple CFTR molecules and to promote colocalization of CFTR and other filamin-binding proteins in the apical plasma membrane of epithelial cells.
Molecular aspects of control in epidermal differentiation

The mammalian epidermis is organized into layers of structurally different cells—the basal, spinous, granular and cornified layers—which represent steps in the differentiative process that terminates in cornification and desquamation. Investigation of the molecular mechanisms that control this ordered sequence of events provides clues to the etiology of certain epidermal pathologies. DNA synthesis and mitosis are normally restricted to the basal layer. Several substances have been implicated in the mitotic control of epidermal cells, the loss of mitotic activity being the first major step in normal keratinization. Investigations performed in this laboratory indicate that isolated differentiated nuclei can replicate their DNA which they are inhibited from doingin situ. Addition of a high speed supernate from homogenized differentiated cells inhibited this synthetic activityin vitro suggesting the existence of a cytoplasmic inhibitor of DNA synthesis. It is not known whether mitotic inhibition in differentiated epidermal cells is a function of the inhibition of DNA replication. Contrary to previous assumptions, recent experimental evidence clearly indicates that, unlike DNA synthesis, RNA synthesis occurs in differentiated cells. Correlated with this synthetic activity is the observation that a protein rich in histidine is specifically formed in the granular cells. This protein appears to be a component of the keratohyalin granules which fill the cells of the granular layer. Investigations were conducted in this laboratory to determine whether control of the synthesis of this protein occurs at the level of translation or transcription. Translation,in vitro, of mRNA obtained from isolated populations of each epidermal cell type suggested that control of protein synthesis in the differentiating epidermis is transcriptional, i.e. only in the granular cell is there an mRNA for the histidine-rich protein. Transcription,in vitro, of chormatin isolated from the separated cell populations produced RNA with a ratio of cytidine to uracil consistent with the predicted mRNA for this protein thus providing additional support for the hypothesis that epidermal differentiation is controlled at the level of ‘gene-readout.’
Attribution of apparent arousal and proficiency of recovery from sympathetic activation affecting excitation transfer to aggressive behavior

Abstract In a pretest, subjects' proficiency to recover from sympathetic arousal induced by strenuous exercise was assessed. The results were used to determine conditions of high, intermediate, and low recovery proficiency (fitness). After an assessment of subjects' unprovoked aggressiveness, subjects were aggressively provoked. Within proficiency blocks, they were then given one of two treatments, ( a ) sitting followed by exercising (no decay) or ( b ) exercising followed by sitting (partial decay), and were there-after provided with an opportunity to retaliate against their tormentor. Under conditions of no decay, in which the high levels of arousal experienced were attributable to exertion, the provocation treatment failed to increase aggressiveness significantly, and there were no differences in aggressiveness in the various proficiency conditions in spite of differentiations in the magnitude of prevailing excitatory residues. Under partial decay, in the absence of cues linking arousal to exertion, the magnitude of residual arousal did affect aggressive behavior: In the conditions of intermediate and low recovery proficiency, aggressiveness increased significantly with provocation and was more pronounced than in the condition of high proficiency (best fitness); in the condition of low proficiency (least fitness) aggressiveness was higher than in the condition of intermediate proficiency, but not reliably so.
Diastolic mitral regurgitation with atrioventricular conduction abnormalities : relation of mitral flow velocity to transmitral pressure gradients in conscious dogs

Diastolic mitral regurgitation is a common finding that can be detected with use of Doppler echocardiographic techniques in patients with atrioventricular (AV) conduction abnormalities. With use of simultaneous hemodynamic and Doppler techniques, mitral flow velocity, mitral valve motion and transmitral pressure gradient were studied during 50 cardiac cycles each of spontaneous or atrial paced first- and second-degree AV block in five lightly sedated dogs. Diastolic mitral regurgitation was detected during atrial relaxation on all beats in which ventricular contraction was delayed greater than 190 ms. In all dogs the diastolic regurgitation was associated with a reverse transmitral pressure gradient (3.7 +/- 1.1 mm Hg in first-degree AV block and 3.2 +/- 1.5 mm Hg in second-degree AV block) that occurred primarily as the result of a decrease in atrial pressure with atrial relaxation. These reverse pressure gradients were as large as the maximal forward transmitral gradients in early diastole (2.9 +/- 0.9 mm Hg in first-degree AV block and 3.1 +/- 0.7 mm Hg in second-degree AV block) and larger than the maximal forward pressure gradients at atrial contraction (1.7 +/- 0.5 and 1.4 +/- 0.6 mm Hg, respectively, p less than 0.05). The maximal reverse pressure gradient during atrial relaxation was also as large as the reverse pressure gradient in mid-diastole (2.7 +/- 0.9 and 2.8 +/- 1.0 mm Hg, respectively), associated with deceleration of early diastolic mitral flow. Peak diastolic mitral regurgitation velocity coincided with the maximal reverse transmitral gradient and was usually larger than anterograde mitral flow velocity.(ABSTRACT TRUNCATED AT 250 WORDS)
A statistical model of elasto-plastic asperity contact between rough surfaces

This work models statistically elasto-plastic contact between two rough surfaces using the results of a previous finite element analysis of an elasto-plastic sphere in contact with a rigid flat. The individual asperity contact model used accounts for a varying geometrical hardness effect that has recently been documented in previous works (where geometrical hardness is defined as the uniform pressure found during fully plastic contact). The contact between real surfaces with known material and surface properties, such as the elastic modulus, yield strength, and roughness are modeled. The asperity is modeled as an elastic-perfectly plastic material. The model produces predictions for contact area, contact force, and surface separation. The results of this model are compared to other existing models of asperity contact. Agreement exists in some cases and in other cases it corrects flaws, especially at large deformations. The model developed by Chang, Etsion and Bogy is also shown to have serious flaws when compared to the others. This work also identifies significant limitations of the statistical models (including that of Greenwood and Williamson).
High-speed rail network design and station location

To improve the personal mobility, safety, and environmental impact of passenger travel and to strengthen regional and national economies, planners, governments, and transportation companies throughout the world have been building high-speed rail (HSR) systems for more than half a century. Although many early systems were principally government projects, public-private partnerships are increasingly being used to design, build, operate, and maintain these HSR networks. However, engaging the private sector requires a clear understanding of the potential profitability of such a system. A key question affecting this understanding is the configuration of the line in terms of its length, number and location of stations, and ultimate alignment. A computer model was developed; it used station, route, and system data to determine the most profitable routes based on the proposed stations. In addition, a sensitivity analysis was conducted to determine which variables had the greatest impact on the costs and returns o...
Selective vulnerability of the CA1 region of hippocampus to the indirect excitotoxic effects of malonic acid

Abstract The CA1 region of hippocampus is selectively vulnerable to a variety of insults, including hypoxia-ischemia and Alzheimer's disease, but the basis of this regional susceptibility is poorly understood. We examined the regional hippocampal sensitivity to mitochondrial metabolic disruption induced by malonate, an inhibitor of succinate dehydrogenase. The CA1 region was exquisitely sensitive to malonate and the dentate gyrus was extremely resistant; the CA3 region had intermediate sensitivity. This pattern of vulnerability is reminiscent of hypoxic-ischemic damage. Malonate damage was blocked by the N -methyl- d -aspartic acid (NMDA) antagonist, MK-801, but regional susceptibility to malonate did not correlate with the density of NMDA receptors. Instead, malonate toxicity was inversely correlated with activity of succinate dehydrogenase. Our results suggest that regional metabolic capacity may help to determine sensitivity to metabolic/excitotoxic insults such as hypoxia-ischemia.