cssi/SciSciGPT-SciSciNet huggingface dataset:
Solidification-driven orientation gradients in additively manufactured stainless steel

Abstract A sample of 304L stainless steel manufactured by Laser Engineered Net Shaping (LENS) was characterized in 3D using TriBeam tomography. The crystallographic, structural, and chemical properties of the as-deposited microstructure have been studied in detail. 3D characterization reveals complex grain morphologies and large orientation gradients, in excess of 10∘, that are not easily interpreted from 2D cross-sections alone. Misorientations were calculated via a methodology that locates the initial location and orientation of grains that grow during the build process. For larger grains, misorientation increased along the direction of solidification. For grains with complex morphologies, K-means clustering in orientation space is demonstrated as a useful approach for determining the initial growth orientation. The gradients in misorientation directly tracked with gradients in chemistry predicted by a Scheil analysis. The accumulation of misorientation is linked to the solutal and thermal solidification path, offering potential design pathways for novel alloys more suited for additive manufacturing.
Spurious Acceleration Noise on the LISA Spacecraft due to Solar Activity

One source of noise for the Laser Interferometer Space Antenna (LISA) will be time-varying changes of the space environment in the form of solar wind particles and photon pressure from fluctuating solar irradiance. The approximate magnitude of these effects can be estimated from the average properties of the solar wind and the solar irradiance. We use data taken by the ACE (Advanced Compton Explorer) satellite and the VIRGO (Variability of solar IRradiance and Gravity Oscillations) instrument on the SOHO satellite over an entire solar cycle to calculate the forces due to solar wind and photon pressure irradiance on the LISA spacecraft. We produce a realistic model of the effects of these environmental noise sources and their variation over the expected course of the LISA mission.
Integrated Network-Based Approach for the Treatment & Prevention of IBD with Natural Products

Gut microbiome dramatically impacts human health and an imbalance in its composition can lead to diseases like Inflammatory Bowel Disease (IBD)- ulcerative colitis (UC) and Crohn's disease (CD). Identifying the molecular targets of IBD among the small molecules present in herbs can help in modulating the gut microbiome-mediated metabolic reactions and disease pathways. However, the diversity of the herbal compounds and the complexity of their mechanism-of-action pose great challenges in using natural products as alternatives to its synthetic counterfeit. To overcome this challenge, we can leverage the effectiveness of genomics and systems biology approaches for identifying new herbal drug-target associations, and potentially replace synthetic medicines with herbal drugs. Motivated by this goal, in the present study, we propose a novel network-based integrated framework, to elucidate the importance of herbal drugs in drug-repurposing and complementary medicine. We uncover the common elements between the herbal compounds (HCs) and the approved drugs (ADs) used in the treatment of IBD using an integrated network-based framework which comprises of the following three networks: (i) a drug-target network of IBD target genes and drugs (both ADs and HCs), (ii) a chemical fragment-based similarity network of chemical fragments identified using molBLOCKS suite from both ADs and HCs, and (c) a protein domain-based similarity network of conserved domains of IBD target proteins. With the help of case studies using approved drugs (e.g., Mesalazine, and Sulfasalazine) and herbal compounds (e.g., quercetin, and curcumin), we successfully demonstrate the power of in silico models in uncovering new drug-target associations and potential natural drug-repurposing and complementary medicine strategies in the prevention and treatment of IBD.
The Fourier coefficients of a metaplectic Eisenstein distribution on the double cover of SL(3) over Q

Abstract We compute the Fourier coefficients of a minimal parabolic Eisenstein distribution on the double cover of SL(3) over Q . Two key aspects of the paper are an explicit formula for the constant term, and formulas for the Fourier coefficients at the ramified place p = 2 . Additionally, the unramified non-degenerate Fourier coefficients of this Eisenstein distribution fit into the combinatorial description provided by Brubaker-Bump-Friedberg-Hoffstein [3] .
Plasma Citrulline as a Biomarker for Early Diagnosis of Necrotizing Enterocolitis in Preterm Infants.

Objective Citrulline synthesized by healthy enterocytes and decreases with injury. This work aimed to study plasma citrulline concentrations (CITs) as a biomarker to differentiate among infants presenting with early nonspecific signs and symptoms of necrotizing enterocolitis (NEC) with those who will develop NEC. Further to study the correlation between posttreatment CIT with time to full feeds (TTFF) and length of stay (LOS). Study Design This is a prospective study which included infants Results The three groups were similar in clinical characteristics. Median CIT (µmol/L) in Group 1 (15.4 [interquartile range, IQR: 7.3–18.0]) was lower than Group 2 (22.2 [IQR: 18.3–27.3], p = 0.02) and Group 3 (24.9 [IQR: 19.8–31.9], p = 0.009). Posttreatment CIT in Group 1 did not correlate with TTFF (r = 0.15; p = 0.69) and LOS (r = − 0.33; p = 0.38). Conclusion CIT was lower in infants with NEC as compared with healthy controls and those infants with nonspecific signs of NEC. CIT after treatment does not correlate with TTFF and LOS. Key Points
Changes in Renal Blood Flow, Glomerular Filtration, and Vasoactive Hormones in Bone-Marrow-Transplant Recipients After Total-Body Irradiation

Although the potential for radiation to produce renal damage at high doses has been well established, there are a few data regarding early functional and hormonal changes in the normal human kidney exposed to “tolerable dose” levels. We measured renal blood flow, glomerular filtration rate (GFR), plasma renin activity, and 6-keto-PGF1α in patients undergoing fractionated total-body irradiation (1320 rads, 13.2 Gy) prior to allogeneic bone marrow transplantation. Both renal plasma flow and GFR rose (23.8% and 28.4%, respectively), while renal vascular resistance fell. GFR rose to levels well above normal, associated with a fall in serum creatinine. These changes were accompanied by a rise in plasma renin activity and urinary 6-keto-PGF1α. We propose that irradiation at these doses induces mild renal vascular injury, allowing net vasodilation and hyperfiltration to occur. Such changes represent a hitherto-unrecognized response to whole-body irradiation.
Lewis Acid Effects on Calculated Ligand Electronic Parameters

Adding Lewis acids to coordinated ligands can impart systematic changes to their properties. We computationally explored the effects of acid-induced changes to the donor strength (Tolman electronic...
Improving the Differential Diagnosis of Otitis Media With Effusion Using Wideband Acoustic Immittance.

OBJECTIVES The objective of this work is to determine whether there is a systematic effect of middle ear effusion volume on wideband acoustic immittance in children with surgically confirmed otitis media with effusion. DESIGN Wideband acoustic immittance was measured in 49 ears from children (9 months to 11 years) who had a diagnosis of otitis media with effusion and compared to 14 ears from children (10 months to 10 years) without a recent history of otitis media. For children with otitis media with effusion, wideband acoustic immittance testing took place in the child's preoperative waiting room before surgical placement of tympanostomy tubes. Testing was completed in a pressurized condition (wideband tympanometry) for all ears as well as in an ambient condition in a subset of ears. Intraoperative findings regarding effusion volume were reported by the surgeons immediately before tube placement and confirmed following myringotomy. This classified the volume of effusion as compared to middle ear volume categorically as either full, partial, or clear of effusion. The type of wideband acoustic immittance explored in this work was absorbance. Absorbance responses were grouped based on effusion volume into one of four groups: full effusions, partial effusions, ears clear of effusion at the time of surgery, and normal control ears. Standard tympanometry was also completed on all ears. RESULTS Absorbance is systematically reduced as the volume of the middle ear effusion increases. This reduction is present at most frequencies but is greatest in the frequency range from 1 to 5 kHz. A multivariate logistic regression approach was utilized to classify ears based on effusion volume. The regression approach classified ears as effusion present (full and partial ears) or absent (clear ears and normal control ears) with 100% accuracy, ears with effusion present as either partial or full with 100% accuracy, and ears without effusion as either normal control ears or ears clear of effusion with 75% accuracy. Regression performance was also explored when the dataset was split into a training set (70% of the data) and a validation test set (30% of the data) to simulate how this approach would perform on unseen data in a clinical setting. Accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve are reported. Overall, this approach demonstrates high sensitivity and specificity for classifying ears as effusion being present or absent and as present effusions being full or partial with areas under the curve ranging from 1 to 0.944. Despite the lack of effusion present in both clear ears and normal control ears, this approach was able to distinguish between these ears, but with a more moderate sensitivity and specificity. No systematic effect of effusion volume was found on standard tympanometry. CONCLUSIONS Wideband acoustic immittance, and more specifically, absorbance, is a strong and sensitive indicator of the volume of a middle ear effusion in children with otitis media with effusion.
Instigators of COVID-19 in Immune Cells are Increased in Tobacco Cigarette Smokers and Electronic Cigarette Vapers Compared to Non-smokers.

INTRODUCTION: SARS-CoV-2, the virus responsible for the COVID-19 pandemic, gains entry into the host cell when its Spike protein is cleaved by host proteases TMPRSS2 and furin, thereby markedly increasing viral affinity for its receptor, angiotensin-converting enzyme-2(ACE2). In rodent and diseased human lungs, tobacco cigarette(TCIG) smoke increases ACE2, but the effect of electronic cigarette vaping(ECIG) is unknown. It is unknown whether nicotine (in both TCIGs and ECIGs) or non-nicotine constituents unique to TCIG smoke increase expression of key proteins in COVID-19 pathogenesis. METHODS: Immune (CD45+) cells collected before the pandemic in otherwise healthy young people, including TCIG-smokers(n=9), ECIG-vapers(n=12) or non-smokers(NS) (n=12) were studied. Using flow cytometry, expression of key proteins in COVID-19 pathogenesis were compared among these groups. RESULTS: TCIG-smokers and ECIG-vapers had similar smoking or vaping burdens as indicated by similar plasma cotinine levels. TCIG-smokers compared to NS had a significantly increased percentage of cells that were positive for ACE2 (10-fold, p<0.001), TMPRSS2 (5-fold, p<0.001) and ADAM17 (2.5-fold, p<0.001). Additionally, the mean fluorescence intensity (MFI) consistently showed greater mean ACE2 (2.2-fold, p<0.001), TMPRSS2 (1.5-fold, p<0.001), furin (1.1-fold, p<0.05) and ADAM17 (2-fold, p<0.001) in TCIG-smokers compared to NS. In ECIG-vapers, furin MFI was increased (1.15-fold, p<0.05) and TMPRSS2 MFI tended to be increased (1.1-fold, p=0.077) compared to NS. CONCLUSIONS: The finding that key instigators of COVID-19 infection are lower in ECIG-vapers compared to TCIG-smokers is intriguing and warrants additional investigation to determine if switching to ECIGs is an effective harm reduction strategy. However, the trend towards increased proteases in ECIG-vapers remains concerning. IMPLICATIONS: This is the first human study to report a marked increase in proteins critical for COVID-19 infection, including ACE2, TMPRSS2 and ADAM17, in immune cells from healthy tobacco cigarette smokers without lung disease compared to e-cigarette vapers and non-smokers. These findings warrant additional investigation to determine if switching to electronic cigarettes may be an effective harm reduction strategy in smokers addicted to nicotine who are unable or unwilling to quit, The increase in proteases in electronic cigarette vapers remains concerning.
Understanding Speech in the Context of Variability

A longstanding theoretical problem in understanding the mechanisms of speech perception is the lack of invariant mappings between acoustic patterns and perceptual interpretation of speech. Speech sounds are coarticulated into the context of an utterance so their patterns change in different phonetic contexts. Variations in production between speakers and differences in speaking rate change the way speech patterns are manifest. The lack of invariance problem is a computational problem that has not been solved either by articulatory/motor theories or by theories based on using higher-level knowledge. Some theories of speech perception ignore lack of invariance and accept variability as noise in recognition. We argue that theories of speech perception need to address contextual variability in the basic architecture of recognition rather than compensate through specialized knowledge or statistical inference. We discuss the nature of this computational problem in perception and the implications for neural mechanisms of speech perception.
Activation of the serratus anterior and upper trapezius in a population with winged and tipped scapulae during push-up-plus and diagonal shoulder-elevation.

Objectives Scapular winging and tipping are types of abnormal scapular kinematics, which is caused by not only the entrapment of peripheral nerve, but also imbalance of the scapulothoracic musculatures. The purpose of this study was to investigate the presence of muscular imbalance in the middle and lower parts of the serratus anterior and upper trapezius in people with scapular winging and tipping. Methods Twenty male participants (age, 23.0 ± 1.92 y) were placed into symptomatic group (n = 10) and control group (n = 10). Participants completed two individual trials of a push-up plus, and a diagonal shoulder elevation, while electromyography (EMG) recorded muscle activity of the low and middle serratus anterior and upper trapezius. The root mean squared EMG values for three muscles were normalized using maximum voluntary isometric contractions (%MVIC). The value was calculated using modified isolation equation for comparing activation of middle and lower serratus anterior (%isolation). Results During a diagonal shoulder elevation, the % maximal voluntary isometric contraction (%MVIC) data showed that the symptomatic participants had significantly greater activation of the middle serratus anterior compared to the control group (P = 0.01). During a diagonal shoulder elevation, the symptomatic participants had not only significantly increased %isolation of the middle serratus anterior, but also significantly decreased for the lower serratus anterior compare with the control group (p = 0.00). Conclusion Present result indicated that different muscle activation between middle and lower serratus anterior could represent in group with scapular dyskinesis, and need for selective activation of the lower serratus anterior in patients with scapular winging and tipping.
Analyzing Ideology in a Japanese Fairy Tale

This article analyzes English-language versions of the Issunboshi fairy tale while discussing Japanese culture and multicultural education. As well as imparting valuable information, it serves as a springboard to exploring Japanese folk and fairy tales for our pleasure, research, or classrooms.
Guest Editorial: Statistical Mining and Data Visualization in Atmospheric Sciences

Data permeates atmospheric science. A full set of sweeps from a NEXRAD-88D radar can record 13 megabytes of data over a five minute period; there are over 120 radar sites across the U.S. At a minimum, 400 megabytes per day of operational gridded numerical weather forecast output are produced at the National Centers for Environmental Prediction. At the National Center for Atmospheric Research in Boulder, Colorado, 150 terabytes of research data are archived on Mass Storage. The National Climatic Data Center maintains over 500 terabytes of global climate records. These are but a few examples of data in the U.S. There are massive volumes of atmospheric empirical observations and model output collected and stored at various operational facilities and research organizations around the world.
Characterizing dynamic and leakage power behavior in flip-flops

This paper presents a detailed analysis of power consumption in a variety of flip-flop designs including scannable latches. The analysis was performed by implementing and simulating the different designs using 70 nm, 1 V CMOS technology. First, we perform a detailed characterization of the dynamic power consumption due to output transitions, and that due to clock and data transitions when there is no output transition. Further, we also characterize the leakage behavior of each of the flip-flop designs and specifically, characterize the input dependence of leakage.
Antagonizing ClpP: A New Power Play in Targeted Therapy for AML

In this issue of Cancer Cell, Cole and colleagues report a non-mutant mitochondrial protein (ClpP) that is overexpressed in a wide range of acute myeloid leukemia (AML) cases, but not in normal hematopoietic precursors. This finding suggests a potentially unique therapeutic targeting opportunity for this difficult-to-treat disease.
Model calculations of regional network locations for earthquakes in subduction zones

Algorithms for locating earthquakes recorded by local networks commonly assume a flat-layered velocity structure, even in island arc regions where the presence of a dipping lithospheric slab introduces large lateral velocity variations. Moreover, because seismic stations occur along the narrow island arc, the resulting linear network geometry degrades earthquake location. To model this situation, we trace rays in a spherical earth from hypothetical earthquakes through appropriate velocity models to networks of various geometries. To isolate the effect of the slab, most of the velocity models consist simply of a planar-dipping constant velocity region embedded in a sphere with a constant lower seismic velocity. We then use the calculated P and S travel times to relocate the hypothetical earthquakes with a flat-layered velocity structure. We perform calculations of this kind in a variety of models, varying the dip of the slab, the velocity contrast between the slab and the mantle, the station geometry, and the distance between the earthquakes and the slab-mantle boundary. We also perform calculations in more realistic models with geometry closely resembling two seismic networks in Alaska. These model calculations emphasize the great care that seismologists should exercise when interpreting local network locations in island arc regions. In the present study, all the relocations incorporate P and S arrivals at all stations, and include no random or “picking” errors. Nevertheless, the relocated hypocenters differ from the “actual” model hypocenters by up to 100 km or more and produce significant distortions in the Wadati-Benioff zone. The most prominent spurious feature is a clear increase in the apparent dip of the Wadati-Benioff zone beneath a certain depth. Furthermore, the relocation reduces the width or apparent thickness of the Wadati-Benioff zone, e.g., they produce an apparent thickness of 5 km or smaller for a zone of earthquakes with an “actual” thickness of 20 km. However, if different combinations of stations report different events, it is possible to determine an apparent thickness which exceeds the “actual” thickness. For local networks near subduction zones, it is useful to estimate the mislocation and rms residual expected for each event recorded and located. This can be accomplished by performing model calculations in a simple model with a constant velocity, dipping slab embedded in a half-space. For such a simple model, there exists only one ray path from each earthquake within the slab to each station, and the travel time for this path can be calculated as a part of the routine network location process. A relocation using the routine network location algorithm and these calculated travel times provides an indication of the expected mislocation and rms residual for the actual recorded event.
Heterogeneity of alcohol, tobacco, and other substance use behaviors in U.S. college students: A latent class analysis

Abstract Purpose To identify subgroups of college students with distinct profiles of traditional and alternative types of tobacco, alcohol, and other substance use and to examine how demographic characteristics and academic and social activities are associated with subgroup membership. Methods We used latent class analysis to characterize subgroups of individuals in their fourth-year of college based on their patterns of seven substance use behaviors: extreme heavy episodic drinking (HED), cigarette use, cigar/cigarillo/little cigar use, smokeless tobacco use, hookah use, marijuana use, and non-medical prescription drug use. Demographic characteristics and academic and social activities were then incorporated as predictors of these latent classes. Results We identified five classes defined by unique behavior patterns: (1) Non/Low Users, (2) Non-Hookah Tobacco Users, (3) Extreme HED & Marijuana Users, (4) Hookah and Marijuana Users, and (5) Poly-Substance Users. Being male, older, and involved in sports were associated with greater odds of being in the Poly-Substance User class compared to the Low/No User class, and participating in an honors society and reporting more positive peer relationships were associated with being in the Hookah and Marijuana User class compared to the Low/No User class. Conclusion Our findings of unique characteristics in the subgroups identified suggest that college substance users are a heterogeneous population requiring different targeted interventions. Of particular concern are subgroups with high rates of alternative tobacco products, as perceived risks of use may be inaccurate and this is not currently a focus of college substance use prevention interventions.
A bi-directional electrothermal electromagnetic actuator

A bi-directional microactuator powered by the combination of electrothermal and electromagnetic forces is successfully demonstrated using both the Poly-MUMPs surface micromachining process and a 50 /spl mu/m SOI process. High output force has been measured from fabricated actuators in both DC and AC operations at non-resonant frequencies. Surface micromachined actuators can move several microns and exert more than 100 /spl mu/N of force, while the larger SOI actuators can move several tens of microns and exert more than 20 mN of force. Reliability tests show that the SOI and surface machined actuators have been in operation for more than 1 million and 100 million cycles, respectively, with no sign of degradation.
Global poverty: four normative positions

Global poverty is a huge problem in today's world. This survey article seeks to be a first guide to those who are interested in, but relatively unfamiliar with, the main issues, positions and arguments in the contemporary philosophical discussion of global poverty. The article attempts to give an overview of four distinct and influential normative positions on global poverty. Moreover, it seeks to clarify, and put into perspective, some of the key concepts and issues that take center stage in the philosophical discussion of global poverty. The four positions to be discussed are labeled the Maximalist Position, the Minimalist Position, Intermediate Position I and Intermediate Position II. After an account of these four distinct positions, we turn, in the conclusion, to a discussion of what role empirical sciences such as economics and political science should play in normative considerations about global poverty.
Extension of River Flow Records in Argentina from Long Tree-Ring Chronologies

: Tree-ring chronologies were derived from two coniferous species growing in the foothills of the Patagonian Andes of Argentina, using crossdating and standardization techniques developed by the Laboratory of Tree-Ring Research. Seven of these chronologies were selected, along with data from two long reliable gaging stations to reconstruct annual stream-flow for two major rivers extending back to the year 1601. Calibration between tree-ring and river flow data was established using the multivariate technique of canonical analysis. Correlations of 0.73 were obtained between gaged and reconstructed flow for both rivers. These Andean conifers contain good climatic and hydrological information and tree-ring chronology and calibration techniques are capable of extracting much of this information.
Simon Newcomb, Percy Daniell, and the History of Robust Estimation 1885–1920

Abstract This article reviews some of the history of robust estimation, emphasizing the period 1885–1920 and the work of Newcomb, Edgeworth, Sheppard, and Daniell. Particular attention is paid to lines of development which have excited recent interest, including linear functions of order statistics and mixtures of normal densities as models for heavy-tailed populations.
Parkinson's Disease: Background, Diagnosis, and Initial Management

Parkinson's disease is a common neurodegenerative disorder associated with aging. After essential tremor, it is the most common movement disorder of the elderly. Parkinson's disease is the most common disabling movement disorder. This article reviews the major clinical features, differential diagnosis, approach to diagnosis, and initial management of Parkinson's disease.
Melanocytic nevi as biomarkers of breast cancer risk.

report on their number of moles using qualitative categories as follows: ‘‘none,’’ ‘‘a few,’’ ‘‘many,’’ or ‘‘very many.’’ The cohort was followed through 2008; a total of 5,956 incident breast cancer cases were ascertained over nearly 1.4 million personyears. In age-adjusted models, women reporting the most nevi were observed to have 13% higher breast cancer risk than their counterparts without nevi (p for trend=0.04). This association was attenuated and the trend no longer significant when investigators adjusted for benign breast disease or family history of breast cancer. A non-statistically significant increase in breast cancer risk of 8% was observed after adjusting for established breast cancer risk factors and measures of ultraviolet radiation exposure. While their findings are broadly consistent, subgroup findings in the two studies were different. Kvaskoff and colleagues found no significant association in postmenopausal women, but observed that, among premenopausal women, those who had reported ‘‘very many’’ nevi were 34% more likely to be diagnosed with breast cancer compared to counterparts who reported ‘‘none’’ even after adjustment for all potential confounders (p for trend=0.03, p for heterogeneity=0.04). In contrast, Han and colleagues found no significant modification of the risk association by menopausal status. The association between nevi and breast cancer risk is unlikely to be causal. Both melanocytic nevi and melanoma are derived from melanin-producing cells in dermal or epidermal tissues [5]; in contrast, most breast cancers are thought to arise from epithelial cells of ductal or lobular origin [6]. Given their
Religious pluralism and justified Christian belief: A reply to Silver

In 'Religious Experience and the Facts of Religious Pluralism', David Silver offers a novel objection to Alvin Plantinga's argument for the rationality of Christian belief.1 Silver argues that on Plantinga's own assumptions, if one receives testimony to the falsity of Christianity, and if one believes that the testifier is honest and that he believes that Christianity is false in the basic way, then one thereby acquires an undefeated defeater for an otherwise justified belief that Christianity is true. That is, Silver argues that even if one could rationally accept Christian belief acquired in the basic way given the absence of contra-Christian testimony, upon receiving that testimony one cannot rationally maintain Christian belief. Therefore, since there is an abundance of (presumably honest) testimony to the falsity of Christianity in the facts of religious pluralism, and since contra-Christian beliefs are often acquired in the basic way, Christian belief is unjustified. I will argue that Silver is mistaken because he does not consider the way in which Plantinga believes we ordinarily (and ought to) adjudicate between conflicting basic beliefs. Once this is taken into account, it will be clear that on Plantinga's epistemological theory, contra-Christian testimony does not entail that one ought to abandon one's basic belief that Christianity is true, no matter how much such testimony one encounters.
The Evolving Role of Antiretroviral Drug Resistance Testing in HIV-Infected Individuals

Scientific advances have made HIV resistance testing routinely available to clinicians and other HIV caregivers. However, interpretation of HIV resistance results is complicated by the lack of knowledge of the clinical consequences of specific genotypic and phenotypic results for most antiretroviral agents. Limitations of viral genotype and phenotype HIV resistance testing include factors such as lack of uniform quality assurance, turn around time, cost, and insensitivity to those mutant strains present in less than 20% to 30% of the viral population. Since there are currently no multicenter prospective data that compare and support the use of one type of resistance testing over another, clinicians who are caring for HIV-infected individuals should become familiar with the pros and cons of the available assays. Clinicians will need to watch for new developments in HIV resistance testing that are on the horizon and will become available in years to come.
Antiviral Drugs in Pediatrics

• Pediatricians are made familiar with antiviral drugs and are provided with specific recommendations for treatment of viral diseases. The antiviral drugs in clinical use today are discussed in terms of their doses, routes of administration, mechanisms of action, established and potential efficacies, and toxicities. These drugs include acyclovir, amantadine, trisodium phosphonoformate, ganciclovir, ribavirin, rimantadine, vidarabine, and zidovudine. Biologic response modifiers, such as interferons, are mentioned briefly in their historical context. Future trends in antiviral therapy are anticipated with mention of the most promising candidate compounds currently in preclinical trials. ( AJDC . 1989;143:1307-1316)
Antithrombin nanoparticles improve kidney reperfusion and protect kidney function after ischemia-reperfusion injury

In the extension phase of acute kidney injury, microvascular thrombosis, inflammation, vasoconstriction, and vascular endothelial cell dysfunction promote progressive damage to renal parenchyma after reperfusion. In this study, we hypothesized that direct targeting and pharmaceutical knockdown of activated thrombin at the sites of injury with a selective nanoparticle (NP)-based thrombin inhibitor, PPACK (phenylalanine-proline-arginine-chloromethylketone), would improve kidney reperfusion and protect renal function after transient warm ischemia in rodent models. Saline- or plain NP-treated animals were employed as controls. In vivo 19F magnetic resonance imaging revealed that kidney nonreperfusion was evident within 3 h after global kidney reperfusion at 34 ± 13% area in the saline group and 43 ± 12% area in the plain NP group and substantially reduced to 17 ± 4% (∼50% decrease, P < 0.05) in the PPACK NP pretreatment group. PPACK NP pretreatment prevented an increase in serum creatinine concentration within 24 h after ischemia-reperfusion, reflecting preserved renal function. Histologic analysis illustrated substantially reduced intrarenal thrombin accumulation within 24 h after reperfusion for PPACK NP-treated kidneys (0.11% ± 0.06%) compared with saline-treated kidneys (0.58 ± 0.37%). These results suggest a direct role for thrombin in the pathophysiology of AKI and a nanomedicine-based preventative strategy for improving kidney reperfusion after transient warm ischemia.
Conductivity of a chronic wound model

The dermal equivalent matrix (DEM) is well recognized as an in vitro model of wound healing. To quantify the low-frequency (10-100 Hz) electric fields that cause proliferative effects in this model, determination of conductivity is a prerequisite. This article outlines a four-electrode technique to establish conductivity of DEM at 100 Hz. DEM is fabricated from human foreskin fibroblasts and collagen type I extracted from rat tail. Over 8-10 days, fibroblasts contract translucent collagen matrices into opaque circular "dime-sized" structures that are approximately 10 mm in diameter and 1 mm thick. To determine conductivity, rectangular samples are cut from each matrix. Thickness and width of each sample is measured by microscopy. Over 17 experiments, conductivity of multiple samples is found to be related inversely to cell density in matrix, with 1.22 Siemens/meter (S/m) corresponding to 0 cells/mm3 matrix and 0.78 S/m corresponding to 2.6 x 10(4)cells/mm3. These results are consistent with a physical model of DEM consisting of pores within a framework of type I collagen; the cells and medium are within the pores. The model is most compatible with a relative pore area of 73% and a cell volume of 9.0 x 10(-6)mm3 (the latter in agreement with published fibroblast dimensions). From these results, DEM is much more porous than dermis. Although DEM has been recognized as a reasonable model of chronic wound healing, this dissimilarity is noted.
Anisotropic dielectric constant of TTF-TCNQ observed by dielectric resonance

Abstract Independent measurements at low temperatures of the anisotropic dielectric constant (∈ 1 ) of TTF-TCNQ are reported. The measurements utilize dielectric resonance techniques to determine ∈ B 1 and ∈ a 1 on the same crystal. The results confirm the unusually large value for ∈ b 1 (4.2 K) > 10 3 and the anisotropic behavior ∈ b 1 (4.2 K) > 10 2 found earlier in cavity perturbation studies of TTF-TCNQ.
Astrocytes Induce Oligodendrocyte Processes to Align with and Adhere to Axons

In order to study the signals that control the onset of myelination, we cocultured highly purified postnatal retinal ganglion cells and optic nerve oligodendrocytes under serum-free conditions that promote their survival for at least a month and found that no myelination occurred. Although the addition of optic nerve astrocytes induced the oligodendrocyte processes to align with, and adhere to, axons, myelination still did not occur. The effect of astrocytes was mimicked by removal of polysialic acid from both cell types using neuroaminidase. These findings provide evidence for a novel role for astrocytes in controlling the onset of myelination by promoting adhesion of oligodendrocyte processes to axons. They also suggest that other, as yet unidentified, cell-cell interactions are necessary to induce the myelination process itself.
Transport Properties of H+‐Selective Membranes Containing Amine‐Derivative Ionophores and Mobile Sites

Transport processes in plasticized PVC membranes containing the H+ chromoionophore ETH 5294 and additional tetraphenylborate-type mobile sites were analyzed by employing the potential-step method. Using chronoamperometry, impedance spectroscopy, and UV/VIS absorbance measurements, it is shown that the ionophore behaves as a carrier for protons, when the membranes are immersed between two aqueous solutions. It was possible to document the changes in the concentration profiles of both free ionophores and ionic species in some of the membranes. There is no evidence of proton hopping between the ionophores.
Strain hardening regimes and microstructure evolution during large strain compression of high purity titanium

Abstract The sudden increase of strain hardening rates seen after small strains in titanium, was shown to correlate with the onset of deformation twinning. This result appears to match quantitatively with Hall–Petch grain size strengthening. The new twin boundaries appear to reduce the effective grain size.
SU-FF-T-345: Photon Dose Calculation Analysis of a Varian Treatment Planning System Algorithm On a Siemens Linear Accelerator in Inhomogeneous Media

Purpose: To analyze the accuracy of photon dose calculations in inhomogeneous media using the analytical anisotropic algorithm (AAA) and pencil beam convolution (PBC) implemented in Varian Medical Systems' Eclipse treatment planning system with Siemens linear accelerators.Method and Materials: Using a 0.125 cm3ionization chamber in a 3‐layer phantom with cork between water‐equivalent layers, we measured absolute depth doses (DD) for 6 and 15 MV, and 3, 5, 10, and 20 cm square fields. To assess lateral disequilibrium modeling, we irradiated another phantom in which the middle cork layer extended laterally only 2.5 cm beyond the central axis, the remainder of the layer being plastic with 10 and 20 cm square fields. Dose profiles were measured using EDR2 film placed at three depths and with a diode detector array placed in the bottom layer. Calculations were performed using AAA and PBC with inhomogeneity correction in Eclipse. Results: For both 6 and 15 MV, the DD calculated by AAA and PBC agreed with measurement within 2% and 3%, respectively proximal to the inhomogeneity beyond the buildup region. Within the inhomogeneity, the agreement was better than 6% for large fields, however, both algorithms overestimated the dose by up to 20% (AAA) or 55% (PBC) for the 3‐cm 6MV field. Distal to the inhomogeneity, AAA modeled the shape of the buildup more accurately than PBC. Lateral profiles indicated that the shape of the penumbra in the inhomogeneous region and the perturbation at the vertical interface predicted by AAA agreed with film and diode array measurements better than PBC. Conclusion: AAA offered an overall improvement over PBC in inhomogeneous media, particularly for small fields and in interface and buildup regions. The overestimate of dose within the inhomogeneity for small fields motivates further investigation, particularly if AAA is used for IMRT calculations in lung.
Geology of the Kohala submarine terrace, Hawaii

Abstract Analysis of geological and geophysical data collected on the Kohala Terrace reveals a complicated geological history for this section of the submarine terraces that are common along the Hawaiian Ridge. Evidence is found for extensive subsidence, on the order of 1250 m, due to normal faulting of the western flank of the island of Hawaii, as well as in situ submarine volcanism. The Kohala Terrace is composed of lava flows from Kohala, Mauna Kea, Hualalai and probably Mauna Loa volcanoes.
Genome-wide linkage analyses for hypertension genes in two ethnically and geographically diverse populations.

We report the results of a genome-wide linkage scan for hypertension genes in 450 African American hypertensive sibpairs from Jackson, MS, and 539 non-Hispanic white hypertensive sibpairs from Rochester, MN. In the Jackson samples we identified one LOD score peak >1.0 on chromosome 1. In the Rochester sample, no genomic region had a LOD score >1.0. These analyses provide no appreciable evidence of hypertension genes with strong effects independent of other genetic and environmental contexts and suggest that stratified linkage analyses may be required to identify hypertension susceptibility genes in these populations.
Use of Rain and Dry Deposition Compositions for Interpreting Ground-Water Chemistry

Waters from 91 springs in a 130 X 140 km area of west-central Arkansas were analyzed for all the major ions. The yearly flux of these ions in the rain and pure-water extract of the dry deposition 180 km north of this area was measured and assumed to represent the composition of the recharge to the ground water feeding the springs. Cation/Cl-flux ratios were used as a norm for the concentration of ions in the spring waters by evapotranspiration. Ratios above the norm were interpreted as ion exchange or rock dissolution into the ground waters. Ratios below the norm were interpreted as ion adsorption or, for Ca2+, CaCO3 precipitation processes. Na+ and Mg2+ are invariably above the norm. K+, NH+4 and H+ are invariably below the norm; whereas Ca2+ values are about equally divided between above and below the norm. Equivalents of cations above the norm and below the norm were compared for a number of springs to determine the main ground-water processes for each spring. The Na+/Cl- and K+/Cl- norms for the rain water form near-perfect minimum and maximum envelopes, respectively, of the Na+ vs Cl- plots of the spring-water compositions. This is due to the adsorption affinities of the soil for Na+ being low, and for K+ being high.
Nanobeam diffraction fluctuation electron microscopy technique for structural characterization of disordered materials—Application to Al88−xY7Fe5Tix metallic glasses

Abstract A fundamental experimental challenge in understanding the physical properties of non-crystalline (i.e., highly disordered) materials is that of fully characterizing the structural order that is present. Medium-range order is particularly difficult to characterize. Fluctuation electron microscopy (FEM) is a relatively new spatially resolved, diffraction technique that measures statistical fluctuations in the scattering of electrons arising from nanometer-scale ordered regions in a sample. The scattering fluctuations can be measured from dark-field (DF) images (the most common approach) or from a series of nanobeam diffraction (NBD) patterns. Here, the effectiveness of the NBD–FEM method for measuring atomic structure in disordered materials is evaluated. In particular, we show that the NBD–FEM statistical measures of fluctuations in diffraction intensity depend strongly on several instrumental parameters; measurement and analysis methodologies that constrain these parameters to minimize associated artifacts are presented. For illustration, the structure of the Al 88 Y 7 Fe 5 metallic glass is examined. It has been shown previously that the substitution of 0.5 at% Ti for the Al in this alloy significantly increases the glass forming ability. We provide NBD–FEM evidence indicating that the atomic structure of the glass is modified upon microalloying, in agreement with earlier extended X-ray absorption fine structure and high-energy X-ray diffraction studies.
Earthquakes: relationships in a slow slip.

The size and duration of disparate, slow, low-amplitude earthquake processes seem to obey a single scaling law. The relationship is very different from that which governs their more violent and impulsive cousins. With the availability of the Global Positioning System and other technical advances, a growing number of unusual earthquake phenomena occurring at relatively long periods have been recognized. They include deep episodic tremor, low-frequency earthquakes, slow slip events and 'silent' earthquakes. Based on data chiefly from western Japan, Ide et al. report that these 'slow' seismic events follow a unified scaling relationship that clearly differentiates their behaviour from that of 'regular' earthquakes.
The substituent-dependent base-treatment chemistry of (η5-C5H5)Fe(CO)2SiR2SiR2Cl: formation of 1,2-disila-3-metallacyclobutanes, their ring-opened polymers, migrations and substitutions

We report the formation of disilametallacycles, high molecular weight polymers or simple substitution products from the reactions of 1-(cyclopentadienyliron dicarbonyl)-2-chlorodisilanes with bases, LDA or n-BuLi.
The effect of colorants on the properties of rotomolded polyethylene parts

An experimental study is reported on the effect of colorants on the warpage, shrinkage, and mechanical properties of rotomolded polyethylene (PE) parts. Five pigments were investigated (titanium dioxide white, cadmium oxide yellow, iron oxide red, carbon black, and phthalocyanine blue). Their concentration was in the range of 0.11 to 0.36 wt%. The pigments were added to the linear low-density polyethylene (LLDPE) by various techniques, dry blended in low intensity or high intensity mixer or compounded with a single-screw extruder. Some blends also contained 0.077 wt% zinc stearate as surfactant. It was found that zinc stearate surfactant in the dry blend increases warpage by about a factor of 2 and shrinkage by ˜ 30%, but color quality and powder handling properties are improved. The dry-blended pigments concentrate along the fusion lines of the PE particles in rotomolded parts, which results in >50% decrease of impact strength with some pigment-surfactant combinations. Mold pressurization minimizes warpage and shrinkage, but causes no significant improvement in impact resistance. Impact resistance can be improved by using compounded pigments or making two-layer parts with a pigmented outer and unpigmented inner layer.
A diversity guarantee and SNR performance for unitary limited feedback MIMO systems

A multiple-input multiple-output (MIMO) wireless channel formed by antenna arrays at the transmitter and at the receiver offers high capacity and significant diversity. Linear precoding may be used, along with spatial multiplexing (SM) or space-time block coding (STBC), to realize these gains with low-complexity receivers. In the absence of perfect channel knowledge at the transmitter, the precoding matrices may be quantized at the receiver and informed to the transmitter using a feedback channel, constituting a limited feedback system. This can possibly lead to a performance degradation, both in terms of diversity and array gain, due to the mismatch between the quantized precoder and the downlink channel. In this paper, it is proven that if the feedback per channel realization is greater than a threshold, then there is no loss of diversity due to quantization. The threshold is completely determined by the number of transmit antennas and the number of transmitted symbol streams. This result applies to both SM and STBC with unitary precoding and confirms some conjectures made about antenna subset selection with linear receivers. A closed form characterization of the loss in SNR (transmit array gain) due to precoder quantization is presented that applies to a precoded orthogonal STBC system and generalizes earlier results for single-stream beamforming.
Flow-induced aggregation of plankton at a front: a 2-D Eulerian model study

Abstract We use a simple 2-D Eulerian numerical model to illustrate a mechanism whereby depth-keeping swimming behavior on the part of an organism, combined with a convergent flow field at a surface front, can create dense populations. In this model, a steady flow field and vertical diffusivity are prescribed, along with an initial plankton distribution. The plankton swim vertically with speeds that depend only on depth, where the form of that dependence may reflect such factors as the vertical variation in light level or the concentration of some prey organism. The Eulerian nature of the model enables diffusion to be treated explicitly. The numerical model describes the evolution of an initial plankton patch in time. A parameter study illustrates the roles played by diffusion, water velocity and details of the animals’ swimming behavior on patch evolution. Output from the model is compared with data taken at a dense plankton patch observed near a small-scale front in the northern Great South Channel in early June 1989.
The bad seed: PDGF receptors link adult neural progenitors to glioma stem cells

In this issue of Neuron, Jackson et al. show that adult neural stem cells (B cells) express PDGF receptors. Functional analysis of PDGF signaling in these neural progenitors resonates in provocative ways with an older body of literature on PDGF autocrine loops in malignant glioma and with more recent observations on the bHLH transcription factor Olig2.