cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of a minor actinides bearing metallic fuel pin irradiated in EBR-II

Abstract The X501 transmutation experiment irradiated in Experimental Breeder Reactor II (EBR-II) was intended to evaluate the safety and performance of the addition of minor actinides (Am, Np) into the metallic nuclear fuel system. The irradiation of this experiment is also of paramount importance for comparisons between true fast spectrum irradiations (e.g. EBR-II) and shrouded irradiation capsules performed at the thermal neutron spectrum Idaho National Laboratory Advanced Test Reactor. The X501 experimental fuel pins were irradiated to a peak measured burnup of 6.2% fission per initial heavy metal atom. This work reports and discusses Postirradiation Examination results for one of two minor actinide bearing pins from the EBR-II X-501 experiment (X501-G591) with a focus on fuel microstructure evolution. Fuel swelling, fission product distribution, cladding strain, fission gas release, fuel microstructure and fuel cladding chemical interaction were all evaluated. The fission gas release was 79.9% and the microstructure along the fuel pin presented several characteristics very similar to other EBR-II U-Pu-Zr ternary metallic fuel experience. Minor actinides seem to not dramatically affect the overall performance of this candidate transmutation fuel. Scanning Electron Microscopy was also performed and an in-depth characterization of the different regions and phases is presented. Performance data from these irradiations can be used to inform the feasibility of minor actinide transmutation in future reactor systems.
An Alternative to Mother's Own Milk: Maternal Awareness of Donor Human Milk and Milk Banks.

BackgroundThe use of donor human milk is rising. Maternal awareness of donor human milk use, milk donation, and milk banks has not been well described in the United States.Research AimsTo explore m...
Spontaneous Soliton Formation in Photonic-Crystal Ring Resonators

We introduce edgeless photonic-crystal resonators, creating photonic bandgap atop one azimuthal mode. The bandgap affects re-balancing of resonator Kerr-shift to enable spontaneous soliton generation, which we demonstrate by tuning laser onto resonance with the mode.
Conservation officer perceptions of search authority

To date, a great deal of confusion and misinformation surrounds the authority (and therefore potentially wider discretion) that conservation officers possess to search private property, vehicles, a...
Older age impacts radiotherapy-related outcomes in soft tissue sarcoma.

Abstract Background Radiation therapy (RT) is a standard component in the multimodality management of localized soft tissue sarcoma (STS). Increasing studies are focusing on biological modifiers that may influence the host's response to RT, including immunologic mechanisms known to change with the aging process. We hypothesized that the effects of RT would be influenced by age, contributing to differences in treatment outcome. Methods Using Surveillance, Epidemiology, and End Results (1990–2011), we identified 30,898 adult patients (>18 y) with nonmetastatic STS undergoing initial surgery. We compared patient demographics, tumor characteristics, and treatments by age. Multivariable analyses were used to analyze overall survival (OS) and disease-specific survival (DSS). Hazard ratios (HRs) were calculated based on multivariable Cox proportional hazards models. Results Mean age at diagnosis was 56.6 ± 16.8 y, and 33.6% of patients were ≥65 y. Of the total, 52.1% of patients were male and 67% were white; 59.9% of patients underwent surgery alone, 33.3% received adjuvant RT, and 6.8% neoadjuvant RT. On multivariable analysis, age, sex, year of diagnosis, histology, grade, size, marital status, and RT predicted OS, whereas age, year of diagnosis, ethnicity, histology, site, grade, RT, size, and marital status predicted DSS. In all patients, RT was associated with improved OS and DSS compared to surgery alone (median OS 136 ± 13 mo with RT versus 118 ± 9 mo without RT and 5-y OS 63.2 ± 1.4% with RT versus 60.5 ± 1.2% without, P Conclusions RT is associated with improved survival in patients with STS undergoing surgical treatment, but improvements in oncologic outcome with RT were greatest among older patients. Further studies into the mechanism of these age-related effects are needed.
Mechanism of Transcriptional Activation by NtrC

In the case of nitrogen regulatory protein C (NtrC), both nucleotide hydrolysis and transcriptional activation depend on phosphorylation of an aspartate residue in the N-terminal receiver domain of the protein (also called its regulatory domain). In this chapter, the authors review the evidence that the NtrC protein from enteric bacteria, which is a dimer in solution, must form an appropriate oligomer to hydrolyze nucleotide and activate transcription. Because phosphorylation of the N-terminal receiver domain of NtrC is known to increase oligomerization, effects of phosphorylation on NtrC function may be a consequence of effects on oligomerization. Recent evidence from the laboratory indicates that oligomerization determinants of NtrC are located in its central activation domain. Studies of NtrC function have been facilitated by the use of two sorts of tools: mutant forms of NtrC and derivatives of the glnA enhancer. NtrC must be phosphorylated in its receiver domain to hydrolyze ATP and activate transcription. Phosphorylation stimulates the oligomerization of NtrC, and oligomerization is, in turn, required for ATP hydrolysis and transcriptional activation. Because the phosphorylated receiver domain of NtrC functions positively, it is presumably needed for appropriate oligomerization: removing this domain by proteolysis or genetic engineering does not substitute for phosphorylation. However, the unphosphorylated protein is essentially incapable of ATP hydrolysis or transcriptional activation, even when bound to the enhancer.
The Cost and Intensity of Behavioral Interventions to Promote HIV Treatment for Prevention Among HIV-Positive Men Who Have Sex with Men

Recently, behavioral prevention interventions for HIV have been criticized as being ineffective, costly, or inefficient. In this commentary, using HIV-positive men who have sex with men (MSM) as an illustrative high-risk population, we argue that the opposite is true—that behavioral interventions for HIV prevention, if implemented with the populations who need them, are affordable and critical for future prevention efforts. We base this argument on recent evidence showing that (1) adherence to antiretroviral treatment (ART) for prevention purposes is necessary to suppress HIV replication and reduce transmissibility, (2) individuals living with HIV have multiple psychosocial concerns that impact self-care and moderate the potential effectiveness of health behavior interventions, and (3) intensive interventions targeting both concerns together (psychosocial and HIV care) can show clinically significant improvement. We follow by comparing the cost of these types of interventions to the cost of standard clinical treatment for HIV with ART and demonstrate a cost-savings of potential intensive behavioral interventions for, in this case, HIV-positive MSM who have uncontrolled virus. Keeping this evidence in mind, we conclude that individual intervention must remain a mainstay of HIV prevention for certain critical populations.
Correlation Between Limited Education and Transfer of Learning

One of the greatest challenges in designing applications for developing communities is that potential users may have little or no education. We investigate how limited education correlates with cognitive skills for conceptual abstraction, as required for transfer of learning in video-based skills training. Through a controlled experiment we compared 56 participants from low-income communities in India, split into two groups of 28, based on scores of a textual literacy assessment tool. Group A included participants who passed the test cut-off condition; Group B included those who did not. Participants were then rated for their ability to generalize video instructions on how to use a vacuum cleaner to similar, but not necessarily identical, tasks. Results confirmed that: 1) Both groups faced challenges when a skill required generalization from instructional material; 2) Group A performed better than Group B all-around on this learning task; 3) Diversification of examples within instructions helped Group A participants in transfer of learning, but not Group B participants. We conclude with design recommendations for instructional videos for populations with limited education.
Recombinational DNA Repair in Bacteria and the RecA Protein

In bacteria, the major function of homologous genetic recombination is recombinational DNA repair. This is not a process reserved only for rare double-strand breaks caused by ionizing radiation, nor is it limited to situations in which the SOS response has been induced. Recombinational DNA repair in bacteria is closely tied to the cellular replication systems, and it functions to repair damage at stalled replication forks, Studies with a variety of rec mutants, carried out under normal aerobic growth conditions, consistently suggest that at least 10-30% of all replication forks originating at the bacterial origin of replication are halted by DNA damage and must undergo recombinational DNA repair. The actual frequency may be much higher. Recombinational DNA repair is both the most complex and the least understood of bacterial DNA repair processes. When replication forks encounter a DNA lesion or strand break, repair is mediated by an adaptable set of pathways encompassing most of the enzymes involved in DNA metabolism. There are five separate enzymatic processes involved in these repair events: (1) The replication fork assembled at OriC stalls and/or collapses when encountering DNA damage. (2) Recombination enzymes provide a complementary strand for a lesion isolated in a single-strand gap, or reconstruct a branched DNA at the site of a double-strand break. (3) The phi X174-type primosome (or repair primosome) functions in the origin-independent reassembly of the replication fork. (4) The XerCD site-specific recombination system resolves the dimeric chromosomes that are the inevitable by-product of frequent recombination associated with recombinational DNA repair. (5) DNA excision repair and other repair systems eliminate lesions left behind in double-stranded DNA. The RecA protein plays a central role in the recombination phase of the process. Among its many activities, RecA protein is a motor protein, coupling the hydrolysis of ATP to the movement of DNA branches.
Feature Characterization in Scientific Datasets

We describe a preliminary implementation of a data analysis tool that can characterize features in large scientific datasets. There are two primary challenges in making such a tool both general and practical: first, the definition of an interesting feature changes from domain to domain; second, scientific data varies greatly in format and structure. Our solution uses a hierarchical feature ontology that contains a base layer of objects that violate basic continuity and smoothness assumptions, and layers of higher-order objects that violate the physical laws of specific domains. Our implementation exploits the metadata facilities of the SAF data access libraries in order to combine basic mathematics subroutines smoothly and handle data format translation problems automatically. We demonstrate the results on real-world data from deployed simulators.
The next generation Internet and health care: a civics lesson for the informatics community.

Abstract The Internet provides one of the most compelling examples of the way in which government research investments can, in time, lead to innovations of broad social and economic impact. This paper reviews the history of the Internet's evolution, emphasizing in particular its relationship to medical informatics and to the nation's health-care system. Current national research programs are summarized and the need for more involvement by the informatics community and by federal health-care agencies is emphasized.
Upregulation of mucosal 5-HT3 receptors is involved in restoration of colonic transit after pelvic nerve transection.

Background Colonic dysfunction occurs after pelvic autonomic nerve damage. The enteric nervous system can compensate. We investigated the role of mucosal serotonin receptors, 5-HT3 and 5-HT4, in the colonic motility restoration over 2 weeks after parasympathetic pelvic nerve transection in a rat model. Methods Male Sprague-Dawley rats underwent pelvic nerve transection or sham operation. Colonic transit was expressed as the geometric center of 51Cr distribution. Mucosal 5-HT3 and 5-HT4 receptor expression was evaluated by Western blot. Intraluminal pressure increase was measured after 5-HT3 (ondansetron) or 5-HT4 receptor antagonist (GR125487) administration in vitro in sham and denervated distal colons. Key Results At 2 weeks, colonic transit in the denervated group was 30% slower compared to the sham group (P < 0.01). At 1 and 2 weeks, 5-HT3 receptor expression was increased two-fold in the denervated group, compared to shams (P < 0.05). A three-fold smaller dose of ondansetron was required in denervated tissues to inhibit intraluminal pressure rise than in sham colons (P < 0.01). There was no difference in the expression of 5-HT4 receptor or the response to GR125487 in denervated vs sham colons. Conclusions & Inferences Colonic motility was restored to approximately 70% normal over 1 week without further improvement at 2 weeks. Enteric nervous system compensated by upregulating mucosal 5-HT3, but not 5-HT4, receptors.
Comparative Contribution to Dextromethorphan Metabolism by Cytochrome P450 Isoforms in Vitro: Can Dextromethorphan Be Used as a Dual Probe for Both CYP2D6 and CYP3A Activities?

Dextromethorphan (DXM) is a widely used probe drug for human CYP2D6 activity both in vitro and in vivo. In humans, DXM is metabolized to dextrorphan (DXO), as well as 3-methoxymorphinan (MEM) and 3-hydroxymorphinan (HYM). The formation of MEM has been attributed primarily to CYP3A4, and the use of DXM has been debated as a simultaneous probe for CYP3A4 and CYP2D6 activities. Recently, we found that highly purified CYP2D6 has significant DXM N-demethylase activity in addition to its well known DXM O-demethylase activity. Therefore, we desired to further compare the contribution to DXM metabolism by individual human cDNA-expressed cytochromes P450, including 2C8, 2C9, 2C18, 2C19, 2D6, 2B6, and 3A4. Metabolites were quantified following separation by high-pressure liquid chromatography and apparent Michaelis-Menten constants determined for the appearance of DXO and MEM. Intrinsic clearance values were estimated for each P450 and normalized using the average percentage content and relative activity factor approaches for comparison. Simplified kinetic models (when [S] << K(m), V(max)/K(m) = V(o)/[S]) were used at fixed DXM concentrations of 20 (for DXM N-demethylation) and 0.2 microM (for DXM O-demethylation), as well as 2 microM to mimic plasma DXM concentrations in human extensive metabolizers. The results confirm that CYP2D6 contributes at least 80% to the formation of DXO, and CYP3A4 contributes more than 90% to the formation of MEM. All of our in vitro results are consistent and indicate that DXM as a marker for monitoring both CYP2D6 and CYP3A activities is practical in an average human or human liver microsomal preparation.
MULTIVARIATE ANALYSIS FOR MATCHED CASE-CONTROL STUDIES

A multivariate method based on the linear logistic model is presented for the analysis of case-control studies with pairwise matching. This technique enables one to investigate the effect of several variables simultaneously in the analysis while allowing for the matched design. The odds ratio is used as the basic measure of risk. One is able to control for variables which are not matching variables while investigating the odds ratio for a particular factor, and to estimate the change in the odds ratio as the level of one or more interval variables changes. The computing methods used for obtaining maximum conditional likelihood estimates of the parameters of interest are modifications of standard programs for logit regression.
Role of gender on renal interstitial hydrostatic pressure and sodium excretion in rats.

Abstract The objective of this study was to compare renal interstitial hydrostatic pressure (RIHP) and sodium excretion in female and male Sprague-Dawley (SD) rats. The RIHP and pressure natriuresis responses were determined in female (n = 13) and male (n = 8) SD rats. Renal perfusion pressure (RPP) was controlled at two levels (100 and 120 mm Hg). Clearances were taken at each level and RIHP was measured with a chronically implanted polyethylene matrix in all rats. At the lower RPP level, RIHP was similar in both groups of rats (5.2 ± 0.2 mm Hg for female, and 5.5 ± 0.4 mm Hg for male), whereas fractional excretion of sodium (FENa) was significantly lower (P
Sporadic renal cell carcinoma in young adults: presentation, treatment, and outcome.

Abstract Objectives To present our institutional experience with young adult patients treated for sporadic renal cell cancer (RCC) during the past two decades. Sporadic RCC is rare in patients younger than 40 years old, accounting for only 3.4% of cases. Methods A retrospective review of 101 patients with sporadic RCC between the ages of 20 and 40 years was performed. The mean age at diagnosis was 33.7 ± 5.5 years. Tumors were discovered incidentally in 40 patients (40%) and were symptomatic in 61 (60%). Sixteen patients (16%) had distant metastasis at diagnosis. For unilateral disease, 58 underwent radical nephrectomy and 31 nephron-sparing surgery (NSS). For bilateral RCC, 2 patients underwent bilateral radical nephrectomy, 3 underwent bilateral NSS, and 7 underwent NSS on one side and a staged contralateral radical nephrectomy. The mean postoperative follow-up was 48 ± 44 months. Results The overall and cancer-specific 5-year survival rate was 61% and 67%, respectively. Tumor stage ( P P P = 0.001). The 5-year cancer-specific survival rate by pathologic stage was 88% for T1N0M0, 64% for T2N0M0, 61% for T3N0M0, and 0% for N+ and M+ ( P Conclusions The results of our study show that RCC does not behave more aggressively in young adults younger than 40 years old than in older adults. The major determinants of patient survival are tumor stage and grade at presentation. Outcome is similar in select patients whether undergoing NSS or radical nephrectomy.
Reinstatement of LH surges by serotonin neuroleptics in aging, constant estrous rats.

Aged rats in constant estrous (CE) were treated with drugs which effect monoamine metabolism in an attempt to restore the positive-feedback response to estrogen. Prior to treatment, the rats were ovariectomized so as to eliminate indirect effects of drug: ovary interaction which might alter the steroid environment. They then received silastic capsules containing estradiol 17β, SC, immediately (IME, immediate implant group) or 4 weeks after surgery (DEL, delayed implant group), to provide a constant, stable source of estrogen, mimicking the CE condition. Blood samples were taken 3 days after estrogen capsules were implanted to determine if the exogenous steroid induced LH surges in IME or DEL rats. LH surges occurred in 80% of DEL rats, but no IME rats suggesting that a 30-day hiatus from ovarian steroids restored the positive-feedback response in previously acyclic rats. Progesterone (0.5 mg) administered at 1100 hr increased the size of the surge in DEL rats but did not change serum LH levels in IME rats. After 3 days of estrogen exposure, hypothalamic content of serotonin was significantly lower (p <0.05) in DEL rats vs. IME rats, while norepinephrine was not different in either group. Differential effects of estrogen on norepinephrine were not apparent in IME or DEL rats. The changes in serotonin metabolism following estrogen treatment in DEL rats occurred with the onset of LH surges, suggesting a functional correlation. On the other hand, serotonin levels did not change in response to estrogen in IME rats, and LH surges were absent as well. Monoamine neuroleptics were administered to IME rats in an attempt to reestablish positive feedback. I-Dihydroxyphenylalanine (l-DOPA; 200 mg/kg at 1100 hr) stimulated LH surges in 31% of the rats; however, its effectiveness was diminished (8% responding with LH surges) by pretreatment with p-chlorophenylalanine (pCPA; 250 mg/kg at 1600 hr, 19 hours before l-DOPA). LH surges were reinstated in the majority (77%) of IME rats following combined treatment with pCPA + 5-hydroxytryptophan (5-HTP; 50 mg/kg at 1100 hr, 43 hours after pCPA). Since this combination of pCPA + 5-HTP enhances sensitivity to serotonin signals, the drugs may have restored the facilitatory effect of serotonin on LH secretion which is lost in aging constant estrous rats. In conclusion, loss of the positive-feedback response in aging female rats may follow changes in monoamine metabolism resulting from life-long exposure to estrogen. Although metabolic changes occur in all hypothalamic monoamines, this study suggests that a major deficit with regard to this feedback loss residues with serotonin.
The Influence of Computer-Based In-Class Examination Security Software on Students' Attitudes and Examination Performance

Expectancy theory is applied to the use of software that secures the testing environment of in-class examinations. This security software prohibits students from viewing unauthorized material during an examination. The empirical study collected 60 student questionnaire responses completed after using the security software. These responses were used to develop measures for a model derived from expectancy theory. Using structural equation modeling, the model was estimated twice for two different variables. These dependent variables were student attitude towards the security software and the studentâ€™s examination grade. The empirical results indicated that student attitudes were positively impacted by self-efficacy, outcome expectancy, and the softwareâ€™s ease of use. However, student grade was not influenced by any measures in the model. It is concluded that the security software is neutral with regard to student performance, while there are manageable actions faculty can take to positively impact student attitude towards security software.
Low temperature buffer growth for the development of vertical light emitting diodes

One key challenge with the the use of III-nitride materials in solid state lighting devices is the use on thermally and/or electrically insulating substrates. In order to transition the lift-off tehniques from laserbased processing to more benign chemical techniques, it is essential to realize the integration of chemical soluble layers into the LED-growth process. This work presents the comparison of physical and chemical vapor deposition techniques used in the growth of ZnO, one such possible isostructural buffer layer and a comparison of the materials properties of samples grown by low temperature chemical vapor deposition and pulsed laser deposition. The quality of the films was highly dependent on the growth conditions and substrate preparation. For room temperature depostion, amorphous ZnO films were observed, while completely oriented films were observed for 750°C growth. Pulsed chemical vapor deposition of the films at 175°C showed smoother polycrystalline films with c-axis texture. ZnO films were etched at room temperature demonstrating the suitability for chemical liftoff.
A STELLAR ROTATION CENSUS OF B STARS: FROM ZAMS TO TAMS

Two recent observing campaigns provide us with moderate dispersion spectra of more than 230 cluster and 370 field B stars. Combining them and the spectra of the B stars from our previous investigations (~430 cluster and ~100 field B stars) yields a large, homogeneous sample for studying the rotational properties of B stars. We derive the projected rotational velocity Vsin i, effective temperature, gravity, mass, and critical rotation speed V crit for each star. We find that the average Vsin i is significantly lower among field stars because they are systematically more evolved and spun down than their cluster counterparts. The rotational distribution functions of V eq/V crit for the least evolved B stars show that lower mass B stars are born with a larger proportion of rapid rotators than higher mass B stars. However, the upper limit of V eq/V crit that may separate normal B stars from emission-line Be stars (where rotation promotes mass loss into a circumstellar disk) is smaller among the higher mass B stars. We compare the evolutionary trends of rotation (measured according to the polar gravity of the star) with recent models that treat internal mixing. The spin-down rates observed in the high-mass subset (~9 M ☉) agree with predictions, but the rates are larger for the low-mass group (~3 M ☉). The faster spin-down in the low-mass B stars matches well with the predictions based on conservation of angular momentum in individual spherical shells. Our results suggest that the fastest rotators (that probably correspond to the emission-line Be stars) are probably formed by evolutionary spin-up (for the more massive stars) and by mass transfer in binaries (for the full range of B star masses).
A Differential Game Theoretic Approach for Two-Agent Collision Avoidance with Travel Limitations

This work presents a collision avoidance control strategy that solves the Hamilton-Jacobi-Isaacs (HJI) equation for an agent to quickly take action assuming a worst-case scenario. By doing so, the agent can develop a control strategy that is robust to the strategies of other agents with whom collision is possible. Consequently, if the governing dynamics of the agent are sufficient, then a collision can be avoided. We build on the idea of finding control solutions by using a differential game theoretic approach (Mettenheim and Breitner, 2009). This is beneficial because the opposing agent’s strategy is incorporated into the control by assuming it plays the worst-case actions. The approach in this work solves the zero-sum aspects of the control on-line using a fast solution method that operates over partitions in the state space (Goode et al., ASME J Dyn Syst Meas Control, 2011). We form the solution to the Homicidal Chauffeur game which is used to provide the control for an evader attempting to avoid a pursuer, an agent that deviates from its normal path and into that of the evader. Furthermore, the evader is constrained to remain within defined boundaries of its assigned travel area, such as a road lane, water channel, etc. The control strategy consists of three parts: (1) a zero-sum approximation of collision avoidance, (2) high-level path planning, and (3) low-level vehicle control. Each component is explained, and an example is given using a real robotic vehicle control system. Here, we show how the control can be implemented using a simple processor located on a vehicle that seeks to avoid a collision with another oncoming vehicle, making a left turn.
Aortoiliac imaging by projective phase sensitive MR angiography: Effects of triggering and timing of data acquisition on image quality

Abstract To assess the ability of projective phase sensitive magnetic resonance (MR) angiography to visualize the aortoiliac vascular segment, and to determine the effects of triggering and timing of data acquisition on image quality, we studied 18 healthy volunteers, mean age 33.3 ± 11 years, by color Doppler imaging and by MR angiography. MR angiography was performed at 1.5 T using a flow-adjustable gradient-echo (FLAG) sequence operated in both ECG-triggered and non-triggered acquisition modes. The images were graded in a blinded fashion by two independent observers. The data were analyzed using Pearson's chi-square analysis. Eighteen triggered time-resolved and 17 non-triggered, time-averaged MR angiograms consisting of 252 and 17 angiographic images, (AI) respectively, were analyzed. In the triggered mode 69 (27.4%) AI and in the non-triggered mode 2 (11.8%) AI were diagnostic. At least one triggered diagnostic AI was obtained in each subject. The image grades were not statistically different between observers (kappa = 0.6686). In the triggered mode diagnostic images were acquired within ± 90 msec of the peak systolic flow velocity determined by Doppler. The proportion of diagnostic images in the triggered mode was highest (73.3%) within a 30-msec interval before the peak flow. In healthy subjects the aortoiliac segment is reliably visualized by FLAG MR angiography. The optimum results are achieved using the triggered acquisition mode and timing acquisition to the initial 180 msec of the abdominal aortic systolic flow pulse.
Gravitational Wave Burst Source Direction Estimation Using Time and Amplitude Information

In this article we study two problems that arise when using timing and amplitude estimates from a network of interferometers (IFOs) to evaluate the direction of an incident gravitational wave burst. First, we discuss an angular bias in the least squares timing-based approach that becomes increasingly relevant for moderate to low signal-to-noise ratios. We show how estimates of the arrival time uncertainties in each detector can be used to correct this bias. We also introduce a stand-alone parameter estimation algorithm that can improve the arrival time estimation and provide root-sum-squared strain amplitude (h{sub rss}) values for each site. In the second part of the paper we discuss how to resolve the directional ambiguity that arises from observations in three non co-located IFOs between the true source location and its mirror image across the plane containing the detectors. We introduce a new, exact relationship among the h{sub rss} values at the three sites that, for sufficiently large signal amplitudes, determines the true source direction regardless of whether or not the signal is linearly polarized. Both the algorithm estimating arrival times, arrival time uncertainties, and h{sub rss} values and the directional follow-up can be applied to any set of gravitational wave candidatesmore » observed in a network of three non co-located IFOs. As a case study we test the methods on simulated waveforms embedded in simulations of the noise of the LIGO and Virgo detectors at design sensitivity.« less
Accumulation and volatilization of different chemical species of selenium by plants

Selenium (Se) removal from polluted waters and soils is especially complicated and highly expensive. Phytoremediation has been suggested as a low-cost, efficient technology for Se removal. Plants remove Se by uptake and accumulation in their tissues, and by volatilization into the atmosphere as a harmless gas. Unraveling the mechanisms of Se uptake and volatilization in plants may lead to ways of increasing the efficiency of the phytoremediation process. The objectives of this study were: (i) to determine the effect of different Se forms in the root substrate on the capacity of some plant species to take up and volatilize Se; (ii) to determine the chemical species of Se in different plant parts after the plants were supplied with various forms of Se; and (iii) to determine the influence of increasing sulfate levels on plant uptake, translocation, and volatilization of different Se species. Plants of broccoli (Brassica oleracea var. botrytis L.), Indian mustard (Brassica juncea L.), sugarbeet (Beta vulgaris L.) and rice (Oryza sativa L.) were grown hydroponically in growth chambers and treated for 1 week with 20 μM Se as Na2SeO4, Na2SeO3 or L-selenomethionine (SeMeth) and increasing sulfate levels. The data show that shoots of SeO4-supplied plants accumulated the greatest amount of Se, followed by those supplied with SeMeth then SeO3. In roots, the highest Se concentrations were attained when SeMeth was supplied, followed by SeO3, then SeO4. The rate of Se volatilization by plants followed the same pattern as that of Se accumulation in roots, but the differences were greater. Speciation analysis (X-ray absorption spectroscopy) showed that most of the Se taken up by SeO4-supplied plants remained unchanged, whereas plants supplied with SeO3 or SeMeth contained only SeMeth-like species. Increasing the sulfate level from 0.25 mM to 10 mM inhibited SeO3 and SeMeth uptake by 33% and 15–25%, respectively, as compared to an inhibition of 90% of SeO4 uptake. Similar results were observed with regard to sulfate effects on volatilization. We conclude that reduction from SeO4 to SeO3 appears to be a rate-limiting step in the production of volatile Se compounds by plants. Inhibitory effects of sulfate on the uptake and volatilization of Se may be reduced substantially if Se is supplied as, or converted to, SeO3 and/or SeMeth rather than SeO4.
Microstructures of undercooled germanium droplets

Undercoolings at crystal nucleation onset of liquid Ge droplets are measured and the microstructures of the droplets are examined. Undercooling values ranging from 150-415 + or 20 C were obtained. It is observed that for the samples undercooled less than 300 C prior to solidification the grain size was greater than 100 microns; for samples undercooled between 300-400 C the grain size was between 50-100 microns; and for samples undercooled greater than 400 C the grain size was 10-20 microns. Consideration is given to dendritic growth and interfacial undercooling. It is noted that there is a correlation between undercooling and as-crystallized grain structure.
Vibration Isolation of Precision Machine Tools and Instruments

Abstract Successful precision engineering is the balance of robustness of the machine and how benign the environment can be made through isolation to minimize the strains caused by vibration that compromise a machine's accuracy. This paper discusses principally the process of isolating a machine from the disturbances which come from the ground, air and utilities which serve it. Principles are reviewed and the intrinsic dependence on frequency established. Requirements are discussed and the hardware realizations currently available are reviewed. A number of examples of systems with unusually demanding requirements are given to illustrate the diverse nature of the solutions in practice. Some new developing areas are identified as the various topics are presented.
Bridging the gap: simulations meet knowledge bases

Tapir and Krill are declarative languages for specifying actions and agents, respectively, that can be executed in simulation. As such, they bridge the gap between strictly declarative knowledge bases and strictly executable code. Tapir and Krill components can be combined to produce models of activity which can answer questions about mechanisms and processes using conventional inference methods and simulation. Tapir was used in DARPA's Rapid Knowledge Formation (RKF) project to construct models of military tactics from the Army Field Manual FM3-90. These were then used to build Courses of Actions (COAs) which could be critiqued by declarative reasoning or via Monte Carlo simulation. Tapir and Krill can be read and written by non-knowledge engineers making it an excellent vehicle for Subject Matter Experts to build and critique knowledge bases.
Uniaxial deformation behaviour of ternary blends of poly (ethylene naphthalate), poly (ether imide) and poly (ether ether ketone) films

Abstract Ternary blends of PEN with PEI and PEEK were investigated in order (i) to eliminate the neck formation that occurs during deformation in the rubbery state while maintaining the strain induced crystallizability, (ii) to increase the glass transition temperature. For this purpose, we investigated the uniaxial deformation behaviour of miscible and immiscible PEN rich ternary blend films stretched above their glass transition temperatures. The increase of PEI concentration increased glass transition temperature and eliminated the neck formation while decreasing crystallizability. In order to compensate for the latter, the concentration of PEEK was increased which recovered the strain hardening (crystallization) and associated self levelling behaviour while boosting the glass transition temperatures of the final films. PEN crystallization is hindered in blends containing 40% PEI. In these blends, although PEEK can be crystallized at concentrations as low as 10%, PEN remains amorphous. Upon annealing both PEEK and PEN separate from PEI and crystallize into their own domains. © 1998 Elsevier Science Ltd.
Hemodynamics in experimental hypernatremic dehydration with special reference to individual organ blood flow in shock and after rehydration.

Summary: Shock after hypernatremic dehydration in the mini-pig is characterized by low cardiac output but little reduction of arterial blood pressure. Maintenance of pressure is due to extensive arteriolar vasoconstriction in the splanchnic and renal vascular bed, as calculated from their markedly diminished blood flow. The expected preservation of flow to vital organs did occur in the brain and the adrenals, but not in the heart. Sufficient oxygen was probably provided by the elevated hematocrit. After 24 h, intravenous fluid therapy produced adequate rehydration as seen from the correction of azotemia, metabolic acidosis, and hypernatremia; only serum creatinine remained elevated. Although cardiac output increased, it did not reach the initial value. Blood flow to most organs was back to normal, but gastrointestinal and particularly renal blood flow remained diminished.
Sinonasal Disease in Polyostotic Fibrous Dysplasia and McCune–Albright Syndrome†‡§¶

Objectives/Hypothesis: To characterize the spectrum, symptoms, progression, and effects of endocrine dysfunction on sinonasal disease in polyostotic fibrous dysplasia (PFD) and McCune–Albright Syndrome (MAS). Study Design: Retrospective review. Methods: A prospectively followed cohort of subjects with PFD/MAS underwent a comprehensive evaluation that included otolaryngologic and endocrine evaluation, and imaging studies. Head and facial computed tomography scans were analyzed, and the degree of fibrous dysplasia (FD) was graded using a modified Lund–MacKay scale. Those followed for >4 years were analyzed for progression. Results: A total of 106 patients meeting inclusion criteria were identified with craniofacial FD. A majority (92%) demonstrated sinonasal involvement. There were significant positive correlations between the sinonasal FD scale score and chronic congestion, hyposmia, growth hormone excess, and hyperthyroidism (P < .05 for all). Significant correlations were not found for headache/facial pain or recurrent/chronic sinusitis. Thirty-one subjects met the criteria for longitudinal analysis (follow-up mean, 6.3 years; range, 4.4–9 years). Those who demonstrated disease progression were significantly younger than those who did not (mean age, 11 vs. 25 years). Progression after age of 13 years was uncommon (n = 3) and minimal. Concomitant endocrinopathy or bisphosphonate use did not have any significant effect on progression of disease. Conclusions: Sinonasal involvement of fibrous dysplasia in PFD/MAS is common. Symptoms are usually few and mild, and disease progression occurs primarily in young subjects. Concomitant endocrinopathy is associated with disease severity, but not progression.
Effect of Treating Mothers' Depression on Children's Well-Being.

earlier publications (6), this study highlights the complexity of interpreting the benefit of mothers’ medication treatment alone on children’s short-term outcomes. While mothers’ depression symptoms improved regardless of which of three medication regimens they received (escitalopram, bupropion, or the combination of the two), benefits for children were unexpectedly only apparent among mothers treated with escitalopram. This study is notable for its multiple sites and a larger sample size than previously used; data collected by multiple informants; thorough analytic strategies; and, especially, examination of a variety of potential mediators of associations betweenmaternaldepressionandchildoutcomes.Oneofthe
Effects of substrate geometry on growth cone behavior and axon branching

At the leading edge of a growing axon, the growth cone determines the path the axon takes and also plays a role in the formation of branches, decisions that are regulated by a complex array of chemical signals. Here, we used microfabrication technology to determine whether differences in substrate geometry, independent of changes in substrate chemistry, can modulate growth cone motility and branching, by patterning a polylysine grid of narrow (2 or 5 microm wide) intersecting lines. The shape of the intersections varied from circular nodes 15 microm in diameter to simple crossed lines (nodeless intersections). Time-lapse recordings of cultured hippocampal neurons showed that simple variations in substrate geometry changed growth cone shape, and altered the rate of growth and the probability of branching. When crossing onto a node intersection the growth cone paused, often for hours, and microtubules appeared to defasciculate. Once beyond the node, filopodia and lamellipodia persisted at that site, sometimes forming a collateral branch. At nodeless intersections, the growth cone passed through with minimal hesitation, often becoming divided into separate areas of motility that led to the growth of separate branches. When several lines intersected at a common point, growth cones sometimes split into several subdivisions, resulting in the emergence of as many as five branches. Such experiments revealed an intrinsic preference for branches to form at angles less than 90 degrees . These data show that simple changes in the geometry of a chemically homogeneous substrate are detected by the growth cone and can regulate axonal growth and the formation of branches.
On the reality of potential magnetic fields in the solar corona.

Global magnetic field calculations, using potential field theory, are performed for Carrington rotations 1601–1610 during the Skylab period. The purpose of these computations is to quantitatively test the spatial correspondence between calculated open and closed field distributions in the solar corona with observed brightness structures. The two types of observed structures chosen for this study are coronal holes representing open geometries and theK-coronal brightness distribution which presumably outlines the closed field regions in the corona. The magnetic field calculations were made using the Adams-Pneuman fixed-mesh potential field code based upon line-of-sight photospheric field data from the KPNO 40-channel magnetograph. Coronal hole data is obtained from AS&E's soft X-ray experiment and NRL's Heii observations and theK-coronal brightness distributions are from HAO'sK-coronameter experiment at Mauna Loa, Hawaii. The comparison between computed open field line locations and coronal holes shows a generally good correspondence in spatial location on the Sun. However, the areas occupied by the open field seem to be somewhat smaller than the corresponding areas of X-ray holes. Possible explanations for this discrepancy are discussed. It is noted that the locations of open field lines and coronal holes coincide with the locations ofmaximum field strength in the higher corona with the closed regions consisting of relatively weaker fields. The general correspondence between bright regions in theK-corona and computed closed field regions is also good with the computed neutral lines lying at the top of the closed loops following the same general ‘warped’ path around the Sun as the maxima in the brightness. One curious feature emerging from this comparison is that the neutral lines at a given longitude tend systematically to lie somewhat closer to the poles than the brightness maxima for all rotations considered. This discrepancy in latitude increases as the poles are approached. Three possible explanations for this tendency are given: perspective effects in theK -coronal observations, MHD effects due electric currents not accounted for in the analysis, and reported photospheric field strengths near the poles which are too low. To test this latter hypothesis, we artificially increased the line-of-sight photospheric field strengths above 70° latitude as an input to the magnetic field calculations. We found that, as the polar fields were increased, the discrepancy correspondingly decreased. The best agreement between neutral line locations and brightness maxima is obtained for a polar field of about 30 G.
Activin subunit and receptor expression in normal and cleft human fetal palate tissues

Abstract Craniofacial malformations, such as cleft palate, present serious complications in the newborn and are often of unknown etiology. Activin BA subunit deletion leads to cleft palate in mice, but the expression of this protein in the human palate has not been explored. Our goal was to determine the spatial and temporal expression of inhibin/activin subunits; the binding protein, follistatin; and activin receptors in the human fetal palate. Residual human fetal palate tissues, with or without cleft, were collected during routine autopsy at Women and Infants Hospital. Inhibin/activin alpha and beta subunits, follistatin, and activin receptor protein and mRNA expression were studied by immunocytochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR) experiments, respectively. Dimeric activin A levels were compared in cleft and normal palate tissue homogenates by immunoassay. Activin BA, follistatin, and activin receptor type IIA proteins were observed in normal and cleft palate tissues ...
Pregnancy in women with congenital heart disease: the importance of evaluation and counselling.

Issues surrounding the growing population of pregnant women with congenital heart disease are becoming increasingly important as more women with surgically corrected heart conditions reach childbearing age
Lack of evidence of occult human immunodeficiency virus in seronegative individuals at very high risk of infection

Reports of human immunodeficiency virus (HIV) infection in seronegative individuals prompted the authors to investigate subjects who are at very high risk of acquisition of HIV in San Francisco. Nine HIV seronegative subjects were evaluated extensively, eight of whom were drawn from a well-characterized cohort of seropositive and seronegative homosexual men who have been followed prospectively since 1983-1984. These men have calculated probabilities of infection based on a fitted model of between 0.22 and 0.94. One additional subject is an intravenous drug user who has shared needles with HIV-infected individuals extensively. Peripheral blood lymphocytes and monocytes were separately cultured from each subject and evidence of HIV infection was sought by a reverse transcriptase assay, enzyme immunoassay, and immunocytofluorographic analysis for HIV antigens, in situ hybridization, RNA slot blot analysis, and polymerase chain reaction amplification of HIV cDNA. Uncultured monocytes and lymphocytes from each donor were also examined by these techniques. Evidence of HIV infection was not found in the peripheral blood mononuclear cells of these high risk individuals.
A Dual Probe STM Imaging System and a Low Noise Switched-Capacitor Transimpedance Amplifier

This article reports a dual probe STM imaging system that doubles traditional STM frame rate and is capable of being scaled up to perform highly parallel STM imaging. A CMOS MEMS probe array is controlled by two off-chip servo loops to generate two STM images simultaneously. A CMOS switched-capacitor transimpedance amplifier (SCTIA) is integrated with the CMOS MEMS probe to locally sense tunneling current and facilitate future extension to much larger arrays. The SCTIA is sampled at the frequency of 166 kHz to produce an ultra-high transimpedance gain of 88 MQ with a tunnel current bandwidth of 40 kHz. Correlated double sampling is utilized to just 25 fA/√Hz. This novel SCTIA is designed and fabricated achieve an extremely low input referred noise current floor of in a 0.35 μm BiCMOS process, with its core SCTIA occupying an area of just 0.02 mm2.