cssi/SciSciGPT-SciSciNet huggingface dataset:
Clinical Utility of Triplicate En Face Image Averaging for Optical Coherence Tomography Angiography in Glaucoma and Glaucoma Suspects

PReCIS:: Averaging triplicate en face angiograms of the radial peripapillary capillary plexus with optical coherence tomography angiography (OCTA) improves vessel visualization, reduces vessel density parameters, and increases the diagnostic accuracy for glaucoma of one such parameter. Purpose To test the hypothesis that triplicate averaging of the radial peripapillary capillary (RPC) layer improves visualization and diagnostic accuracy of optical coherence tomography angiography (OCTA) for glaucoma. Methods This is a cross-sectional study involving 63 primary open angle glaucoma patients and 70 age-matched glaucoma suspects. Triplicate 6×6mm OCTA scans of the optic nerve head were acquired, and the RPC layer was extracted. RPC en face images were registered and averaged. Parameters of global entropy (GE), global standard deviation (GSD), local texture correlation (LC), local homogeneity (LH), signal-to-noise ratio (SNR), and intercapillary distance (ICD) were used to measure the change in visualization with averaging. Vessel area density (VAD), vessel skeleton density (VSD), and flux parameters were calculated in a 2.8▒mm annulus excluding the optic disc. Diagnostic accuracy of these parameters for glaucoma was assessed by calculating area under the receiver operating curve (AUC) values. Results 3-frame averaging resulted in decreased GE and GSD (Ps Conclusions Triplicate averaging improves visualization of the RPC layer and the diagnostic accuracy of VSD for glaucoma. The impact of image averaging on OCTA diagnostic performance and other potential applications warrants further exploration.
Developing Analytical Skills in Economic Geography: Portuguese Clusters and Their Export Potential

Regional agglomerations of industry have been a focus of economic geography research, especially in terms of how these clusters form and remain successful. Such a core topic should be explored in e...
Chemical Characterization of Two California-Grown Avocado Varieties (Persea americana Mill.) over the Harvest Season with an Emphasis on Sensory-Directed Flavor Analysis.

The research objective was to characterize avocado’s aroma-active volatiles and use information about its overall composition, such as lipid profile, to discuss likely biosynthetic origins. To achi...
Performance of nasal methicillin-resistant Staphylococcus aureus screening for intra-abdominal infections in critically ill adult patients.

Study objective Intra-abdominal infections (IAIs) are a common reason for intensive care unit (ICU) admissions, and methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon pathogen in IAIs. Although more data are available in the setting of non-abdominal sources, there are limited data on the performance of nasal MRSA screening for MRSA IAIs. The primary objective of this study was to evaluate the performance of nasal MRSA screening for MRSA IAIs in critically ill adult patients. Design This was a multicenter, retrospective, cohort study. Setting A 14-hospital healthcare system between January 1, 2014, and August 31, 2019. Patients Adult patients admitted to an ICU for at least 24 h with a diagnosis code for an IAI, a nasal MRSA surveillance screen within 30 days, and an intra-abdominal culture were eligible for inclusion. Intervention The primary outcome was to evaluate the performance of nasal MRSA screening for MRSA IAIs by calculating the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Measurements and main results Out of 863 patients randomly screened, a total of 192 patients were included. The study population had a mean age of 60 (SD ±15) years, and 101 (53%) patients were male. Six (3.1%) patients were positive for an MRSA IAI, of which four (66.7%) demonstrated a positive nasal MRSA screen. A total of 186 (96.8%) patients were negative for a MRSA IAI, of which 19 (10.2%) were nasal MRSA-positive and 167 (89.8%) were nasal MRSA-negative. Nasal MRSA screening demonstrated the following performance: accuracy 89.1% (95% CI: 83.8%-93.1%), sensitivity 66.7% (95% CI: 22.3%-95.7%), specificity 89.8% (95% CI: 84.5%-93.7%), PPV 17.4% (95% CI: 9.4%-30.0%), and NPV 98.8% (95% CI: 96.4%-99.6%). There were no significant differences in clinical outcomes, including renal replacement-free days, ICU and hospital length of stay, and in-hospital mortality. Conclusions Among critically ill adult patients with IAIs, a negative nasal MRSA screen within 30 days may help to empirically exclude MRSA as a causative pathogen.
Species-specific wet-dry mass calibrations for common submersed macrophytes in the Upper Mississippi River

Abstract Submersed freshwater macrophytes can provide numerous crucial ecosystem functions and influence biotic assemblages across multiple trophic levels. These functions are dependent on abundance, which has been most often reported as biomass in terms of dry mass per unit area. Determining dry mass is a time- and labor-intensive process that may not be practical at the assessment scale of interest. We examined the relationship between wet and dry mass during the approximate peak growing season for thirteen submersed species common on the Upper Mississippi River and other aquatic systems in the midwestern USA and beyond (Ceratophyllum demersum, Elodea canadensis, Heteranthera dubia, Myriophyllum sibericum, Myriophyllum spicatum, Narrow-leaf pondweeds (likely included Potamogeton foliosus, P. pusillus), Potamogeton crispus, Potamogeton nodosus, Potamogeton richardsonii, Potamogeton zosteriformis, Ranunculus longirostris, Stuckenia pectinata, and Vallisneria americana). All species exhibited a predictable linear relationship between wet and dry mass. The species-specific dry: wet mass ratios of 5.0–13.1% presented here supplement previously published data for some species, represent novel information for others and allow for estimations of dry mass from fresh material when direct measurement of the former is impractical. Pairwise comparisons of the individual estimates indicated four distinct groups of species within the overall gradient of dry:wet mass ratios. Lowest estimates of percent dry mass were for species previously associated with higher flow (V. americana and H. dubia) and highest values were for species typically found in still water (P. zosteriformis and the P. foliosus/P. pusillus group).
Economic Importance, Practical Limitations to Production, Management, and Breeding Targets of Alfalfa

Alfalfa (Medicago sativa L.) is the most valuable forage crop grown on approximately 30 m ha (74 million acres) worldwide. It is the third most valuable crop harvested in the U.S. behind only corn and soybeans. Alfalfa is widely recognized as a significant component of most dairy and other animal rations because of the multiple benefits it provides: Alfalfa adds valuable fiber, has a faster rate of fiber digestion than grasses, is very palatable, is high in protein, provides needed vitamins, is a good buffer in the rumen, and promotes animal health. In addition, it provides legume nitrogen credits and has rotational yield boost to following crops. It provides environmental benefits in soil remediation, reduced erosion (compared to row crops), and supports varied wildlife by being a source of cover and food from insects, spiders, mites, and earthworms. A major issue is low yield, where the record alfalfa yield in the U.S. is 26 t/a DM with irrigation in Arizona while the average alfalfa yield on a farm in the U.S. is about 4.5 tons/acre DM. The yield problem is a combination of environmental and management issues. Breeding objectives should continue to be resistance to diseases and insects. However, a major long-term direction should be to increase alfalfa yield. Possibly each of the following breeding objectives could contribute: raise limits to natural photosynthesis, reduce dark respiration, develop cultivars that have less leaf loss during harvest, and minimizing the impact of wheel traffic on stands. An additional breeding objective should be to increase the bypass protein of alfalfa. While this will not affect yield, it will increase alfalfa value to users.
Vegetation-type conversion of evergreen chaparral shrublands to exotic annual herb dominated savannahs: Causes and consequences for ecosystem function.

Woody evergreen shrublands are the archetypal community in mediterranean-type ecosystems and these communities are profoundly changed when they undergo vegetation-type conversion (VTC) to become annual herb-dominated communities. Recently, VTC has occurred throughout southern California chaparral shrublands and this implies changes in important ecosystem functions. The mechanisms that lead to VTC and subsequent changes to ecosystem processes following VTC are important to understand as they have regional and global implications for ecosystem services, climate change, land management, and policy. The main drivers of VTC are altered fire regimes, aridity, and anthropogenic disturbance. Some changes to ecosystem function are certain to occur with VTC, but their magnitudes are unclear, whereas other changes are unpredictable. I present two hypotheses: 1) VTC leads to warming that creates a positive feedback promoting additional VTC; and 2) altered nitrogen dynamics create negative feedbacks and promote an alternative stable state in which communities are dominated by herbs. The patterns described for California are mostly relevant to the other mediterranean-type shrublands of the globe, which are biodiversity hotspots and threatened by VTC. This review examines the extent and causes of VTC, ecosystem effects, and future research priorities. This article is protected by copyright. All rights reserved.
Tower Stories: An Oral History of 9/11

Reviewed Medium: book Authors: Damon DiMarco Year: 2007 Pages: 528 Publisher: Santa Monica Press ISBN: 978-1595800213 (hard cover). Prices: $27.95 USD(hard cover).
Spinoza's summum bonum

: As Spinoza presents it, the knowledge of God is knowledge, primarily, of oneself and, secondarily, of other things. Without this know-ledge, a mind may not consciously desire to persevere in being. That is why Spinoza claims that the knowledge of God is the most useful thing to the mind at IVP28. He claims that the knowledge of God is the highest good, however, not because it is instrumental to perseverance, but because it is also the best among those goods that we seek for their own sakes. It is acquiescentia in se ipso, the highest form of laetitia.
H1N1 influenza in lung transplant patients: A follow up after one year

The 2009 outbreak of H1N1 caused significant morbidity and mortality. Long term outcome of H1N1 in lung transplant (LT) patients have not been well characterized. We did a retrospective study of LT patients diagnosed with H1N1 between July and November 2009. Data pertaining to LT, history of influenza, admission information, pulmonary function, radiograph, computer tomography scans, and echocardiograms were identified. Among 181 LT patients, there were 10 PCR confirmed cases of H1N1. Patients had a median of 4 months time since LT to infection, received immunosuppressive therapy, and had not received vaccination against H1N1. 60% of patients presented with fever and cough, others had non-pulmonary complaints and all received oseltamivir upon diagnosis. Consolidation was seen by imaging in 60% of patients. Median FEV1 decreased and remained low over a one-year follow up period (1.72 – 1.51 – 1.54) despite clinical improvement. Two patients progressed to respiratory failure and severe LV dysfunction (EF 20-30%) despite previous normal LV function. These patients were on ECMO and had improvement in cardiac and respiratory status but developed gangrene, vascular necrosis, sepsis, and died. One patient developed acute rejection and two patients developed chronic rejection with one retransplanted in February 2010. LT patients contracting H1N1 infection have significant morbidity ranging from mild disease to severe respiratory failure with cardiac dysfunction. Rapidly deteriorating patients had developed myocardial dysfunction, but continued to decline even when this dysfunction resolved. Increased incidence of chronic rejection and extended decreased pulmonary function is seen among LT patients infected with H1N1.
MIS project teams: an investigation of cognitive style implications

A profusion of technology is insufficient to implement effective computer systems without the full utilization of human resources to develop such systems. The issue of fully developing and utilizing available human resources is currently receiving careful scrutiny in the MIS literature. One methodology for fully utilizing human resources has been maximizing productivity by stressing team effort. This research focuses on evaluating the systems development activities of two MIS project teams. Empirical evidence was gathered from interviews with MIS personnel and key users concerning strengths/weaknesses of the two project teams. Analysis was performed to determine the personality characteristics (as measured by the Myers-Briggs Type Indicator) of the MIS staff. The results of this analysis indicated a void of certain personality styles in project team one. This void correlated with weaknesses ascertained from the interview data for project team one. Project team two, with all four personality types represented, was evaluated as very successful. Recommendations are made for assembling project teams based on these findings.
Studies on the control of antibody synthesis. XV. Effect of nonspecific immunodepression on antibody affinity.

Abstract The effect on antibody affinity of marked nonspecific immunodepression early in the primary response was studied using three different immunosuppressive agents: 6-mercaptopurine, cyclophosphamide, and heterologous antilymphocyte antiserum. Marked nonspecific immunosuppression, even if limited to an early period in the primary response, resulted in a profound decrease in high-affinity plaque-forming cells (PFC) late in the primary response. Boosting led to the rapid appearance of high-affinity PFC, but the average affinity of the secondary PFC population was low in animals immunosuppressed early in the primary response. It would appear that selection for high-affinity B memory cells took place during the primary response despite the absence of detectable high-affinity PFC in the immunodepressed mice. Finally, the data suggest that in the absence of high-affinity antibody production, there may be an increased production of low-affinity antibodies, presumably as a consequence of a lack of antibody-mediated immunoregulation.
Monitoring the fabrication process for as-built analysis and generation

The objective of this paper is to present a theoretical model which will create a computer vision system capable of monitoring the fabrication of a facil- ity. The monitoring process would be able to identify out-of-position components and to re-create an as-built CAD model from the construction process. An as-built schedule would be a direct output and would provide for improved scheduling inter action and analysis. While computer vision .technology has not reached maturity where arbitrarily complex scenes can be processed and "understood", there h reason to believe that a vision system for monitoring the fabrication of a facility can be developed. To create such a vision system will require a number of tasks. The focus of this project is to use the information in the CAD system together with the camera model, the camera location, the orientation of the opti- cal axis and the positions of the illuminators to predict how the objects in the facility should appear. This information can then be used in "top-down" analysis of the scene. In a top-down analysis a scene model is used to guide the search for the objects in the scene. While developing sophisticated computer vision systems has, in general, been difficult, developing sophisticated top-down vision systems has not.
Spectral biomarkers for chemoprevention of colonic neoplasia: A placebo-controlled double-blinded trial with aspirin

Objective A major impediment to translating chemoprevention to clinical practice has been lack of intermediate biomarkers. We previously reported that rectal interrogation with low-coherence enhanced backscattering spectroscopy (LEBS) detected microarchitectural manifestations of field carcinogenesis. We now wanted to ascertain if reversion of two LEBS markers spectral slope (SPEC) and fractal dimension (FRAC) could serve as a marker for chemopreventive efficacy. Design We conducted a multicentre, prospective, randomised, double-blind placebo-controlled, clinical trial in subjects with a history of colonic neoplasia who manifested altered SPEC/FRAC in histologically normal colonic mucosa. Subjects (n=79) were randomised to 325 mg aspirin or placebo. The primary endpoint changed in FRAC and SPEC spectral markers after 3 months. Mucosal levels of prostaglandin E2 (PGE2) and UDP-glucuronosyltransferase (UGT)1A6 genotypes were planned secondary endpoints. Results At 3 months, the aspirin group manifested alterations in SPEC (48.9%, p=0.055) and FRAC (55.4%, p=0.200) with the direction towards non-neoplastic status. As a measure of aspirin9s pharmacological efficacy, we assessed changes in rectal PGE2 levels and noted that it correlated with SPEC and FRAC alterations (R=−0.55, p=0.01 and R=0.57, p=0.009, respectively) whereas there was no significant correlation in placebo specimens. While UGT1A6 subgroup analysis did not achieve statistical significance, the changes in SPEC and FRAC to a less neoplastic direction occurred only in the variant consonant with epidemiological evidence of chemoprevention. Conclusions We provide the first proof of concept, albeit somewhat underpowered, that spectral markers reversion mirrors antineoplastic efficacy providing a potential modality for titration of agent type/dose to optimise chemopreventive strategies in clinical practice. Trial Number NCT00468910
Heart transplantation in patients aged 70 years and older: a two-decade experience.

Abstract Objective Advanced age has been viewed as a contraindication to orthotopic heart transplantation (OHT). We analyzed the outcome of OHT in patients who were aged 70 years or older and compared the results with those in younger patients during a two-decade period. Methods A total of 519 patients underwent first-time single-organ OHT at our institution from 1988 to 2009. Patients were divided into three groups by age: ≥ 70-years old (group 1, n = 37), 60 to 69-years old (group 2, n = 206), and ≤60-years old (group 3, n = 276). Primary endpoints were 30-days, and 1-, 5-, and 10-years survival. Secondary outcomes included re-operation for bleeding, postoperative need for dialysis, and length of postoperative intubation. Results There was no significant difference in survival between the greater than or equal to 70-year-old group and the two younger age groups for the first 10 years after OHT. Survival rates at 30 days, and 1-, 5-, and 10-years, and median survival in group 1 recipients were 100%, 94.6%, 83.2%, 51.7%, and 10.9 years (CI 7.1–11.0), respectively; in group 2 those numbers were 97.6%, 92.7%, 73.8%, 47.7%, and 9.1 years (CI 6.7–10.9), respectively; and in group 3 those numbers were 96.4%, 92.0%, 74.7%, 57.1%, and 12.2 years (CI 10.7–15.4; P = NS), respectively. There was no significant difference in secondary outcomes of re-operation for bleeding, postoperative need for dialysis, and prolonged intubation among the three age groups. Conclusions Patients who are aged 70 years and older can undergo heart transplantation with similar morbidity and mortality when compared with younger recipients. Advanced heart failure patients who are aged 70 years and older should not be excluded from transplant consideration based solely on an age criterion. Stringent patient selection, however, is necessary.
Temporal patterns in the occurrence of Salmonella in raw meat and poultry products and their relationship to human illnesses in the United States

The prevalence and level of microbial pathogens on various commodities often exhibit seasonal patterns. As a consequence, the incidence of foodborne illness tends to follow these trends. Of the various product classes, the occurrence of microbial contamination can be high on raw meat and poultry products, with Salmonella potentially occurring in all meat and poultry product classes. Since 1999, the Food Safety and Inspection Service in the United States has collected samples of meat and poultry products and analyzed them for the presence of Salmonella. This study uses a common modeling approach to estimate the seasonal change in the proportion of test-positive samples for seven classes of raw meat and poultry products. The results generally support the hypothesis of a seasonal increase of Salmonella during the summer months. The proportions of test-positive samples decrease rapidly in the late fall for all product classes except chicken and ground turkey, which remain somewhat elevated through late winter. A comparison of the pathogens' seasonal pattern in meat and poultry with human cases reveals that the seasonal increase in human cases precedes the seasonal increase in meat and poultry by between one and three months. These results suggest that while contaminated meat and poultry products may be responsible for a substantial number of human cases, they are not necessarily the primary driver of the seasonal pattern in human salmonellosis.
Two paradoxes in stuttering treatment

Abstract The premise of this article is that effective communication should be a central, overarching goal in the treatment of stuttering. Not focusing on communication may have some unintended negative consequences on treatment. The negative consequences are the result of two paradoxes that confront clinicians and clients: the listener paradox and the communication paradox. The listener paradox concerns the different ways that typical listeners and clinicians respond to stuttering. The communication paradox concerns the use of treatment procedures that may have negative consequences on communication. Clinicians and clients need to evaluate treatment procedures in terms of the effect they may have on communication. Understanding these two paradoxes and making effective communication the focus of treatment may improve the long-term treatment outcomes of people who stutter. Educational objectives: The reader will learn about (1) why effective communication should be the central goal in the treatment of stuttering; (2) how the listener and communication paradoxes may negatively impact on communication; and (3) how understanding these paradoxes may improve the long-term outcomes of people who stutter and also improve the comfort level clinicians have in treating individuals who stutter.
Morphological variation in a population of grey-crowned babblers: Correlations with variables affecting social behavior

Variation in weight, wing length and bill length in a population of grey-crowned babblers is influenced primarily by sex and age, but correlations with size of social unit, with reproductive success, and with vegetation are also detectable (Table 1). The latter correlations vary with sex, age, and status as helper or breeder. Differential wear according to behavioral role, competition for status, incubation, and inheritance are discussed as possible causal mechanisms. Helpers were not detectably smaller in any dimension than breeders of the same age and sex. Male and female non-breeding helpers differ in patterns of morphological correlation, suggesting that they have different behavioral roles. Breeding males have a unique pattern of morphological correlation, suggesting that their foraging behavior differs from breeding females and non-breeders.
Use of CCl4 and CHCl3 in gas source molecular beam epitaxy for carbon doping of GaAs and GaxIn1−xP

Carbon tetrachloride (CCl4) and chloroform (CHCl3) have been studied as carbon doping sources for the compound semiconductors GaAs, GaP, InP, and Ga0.51In0.49P grown by gas source MBE from elemental Group III sources and thermally cracked Group V hydride sources. Hole concentrations up to 1.3×1020 cm−3 have been measured by Hall effect in CCl4-doped GaAs, which agrees closely with the atomic C concentration from secondary ion mass spectrometry, indicating complete electrical activity of the incorporated carbon. For comparable dopant flow rates, use of CHCl3 results in carbon and hole concentrations approximately a factor of 15 lower than that from CCl4. The sensitivity of carbon incorporation to varying substrate temperature and V/III ratio has been observed to be significantly reduced with CCl4 and CHCl3 from that obtained under similar growth conditions with trimethylgallium (TMG) in metalorganic MBE (MOMBE). The GaAs growth rate is unaffected by the CCl4 flux over the range of CCl4 flow investigated. CCl4 has also been successfully employed as a carbon doping source for GaP, with a hole concentration of 1×1020 cm−3 achieved for growth at 600°C. Films of Ga0.51In0.49P grown at 515°C exhibit only marginal p-type conductivity with p = 5 × 1016cm−3 when doped with CCl4, despite an incorporated atomic concentration of [C] = 5 × 1019cm−3. Films of InP grown at 515°C are n-type with n = 9 × 1017cm−3 despite substantial incorporated carbon equal to 1 × 1020 cm−3.
Interrelationships of circannian rhythms in the ground squirrel, Citellus lateralis

Abstract 1. 1. Experimental abolition, by food deprivation, of the body-weight circannian rhythm in Citellus lateralis did not prevent the onset of hibernation at the same time as in control animals. 2. 2. The experiment makes it necessary to modify a previous postulate that the attainment of a certain maximum body weight was a prerequisite to the onset of hibernation. 3. 3. By comparison with the data from circadian rhythms in other species and various theories concerning these, an attempt has been made to determine whether there is one master circannian clock with various manifestations, or two indepedent clocks which are normally phase-locked. It is argued that the available evidence suggests the latter.
Clostridium difficile toxin B is an inflammatory enterotoxin in human intestine

Abstract Background & aims: Clostridium difficile causes antibiotic-associated diarrhea and pseudomembranous colitis, diseases afflicting millions of people each year. Although C. difficile releases 2 structurally similar exotoxins, toxin A and toxin B, animal experiments suggest that only toxin A mediates diarrhea and enterocolitis. However, toxin A-negative/toxin B-positive strains of C. difficile recently were isolated from patients with antibiotic-associated diarrhea and colitis, indicating that toxin B also may be pathogenic in humans. Methods: Here we used subcutaneously transplanted human intestinal xenografts in immunodeficient mice to generate a chimeric animal model for C. difficile toxin-induced pathology of human intestine. Results: We found that intraluminal toxin B, like equivalent concentrations of toxin A, induced intestinal epithelial cell damage, increased mucosal permeability, stimulated interleukin (IL)-8 synthesis, and caused an acute inflammatory response characterized by neutrophil recruitment and tissue damage. Laser capture microdissection and real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) showed that intestinal epithelial cell-specific IL-8 gene expression also was increased significantly after luminal exposure to C. difficile toxins in vivo. Conclusions: We conclude that C. difficile toxin B, like toxin A, is a potent inflammatory enterotoxin for human intestine. Future therapeutic or vaccine strategies for C. difficile infection therefore need to target both toxins.
Use of vertebroplasty to prevent proximal junctional fractures in adult deformity surgery: A biomechanical cadaveric study

Abstract Background context Vertebral compression fractures at the proximal junction are common complications of long spinal fusion surgeries that can contribute to the development of proximal junctional kyphosis or proximal junctional failure. To our knowledge, no biomechanical studies have addressed the effect of vertebral augmentation at the proximal junction. Purpose To evaluate the effectiveness of prophylactic vertebroplasty in reducing the incidence of vertebral compression fractures at the proximal junction after a long spinal fusion in a cadaveric spine model. Study design Biomechanical cadaveric study. Methods We divided 18 cadaveric spine specimens into three groups of six spines each: a control group, a group treated with one-level prophylactic vertebroplasty at the upper instrumented vertebra, and a group treated with two-level prophylactic vertebroplasty at the upper instrumented vertebra and the supra-adjacent vertebra. In all spines, the pedicles were instrumented from L5 to T10. Using eccentric axial loading, the specimens were then compressed until failure. Failure was defined as a precipitous decrease in load with increasing compression. The effect of augmentation on load-to-failure was checked using linear regression. The effect of augmentation on incidence of adjacent fractures was checked using logistic regression. Differences at the level of p Results Fractures occurred in 12 of 18 specimens: five in the control group, six in the one-level group, and only one in the two-level group; these differences were statistically significant. Conclusions Prophylactic vertebroplasty at the upper instrumented level and its supra-adjacent vertebra reduced the incidence of junctional fractures after long posterior spinal instrumentation in this axially loaded cadaveric model. Additional studies are necessary to determine if these results are translatable to clinical practice.
Evaluation of 'period-generated' control laws for the time-optimal control of reactor power

Time-optimal control of neutronic power has recently been achieved by developing control laws that determine the actuator mechanism velocity necessary to produce a specified reactor period. These laws, designated as the MIT-SNL period-generated minimum-time control laws, function by altering the rate of change of reactivity so that the instantaneous period is stepped from infinity to its minimum allowed value, held at that value until the desired power level is attained, and then stepped back to infinity. The results of a systematic evaluation of these laws are presented. The behavior of each term in the control laws is shown, and the capability of these laws to control properly the reactor is demonstrated. Factors affecting the implementation of these laws are discussed. The results of an experimental study in which these laws were used to adjust the power of the 5 MWt MIT research reactor are shown. >
Metal Speciation and Its Role in Bioaccessibility and Bioavailability

Metals play important but varied roles in human health. Some metals are required for normal metabolic function, with optimal amounts for maximum benefit. Others are only known to cause toxic effects. Most of our knowledge of the function of metals in human health has been acquired in the last 100 years. However, evidence of adverse health effects attributed to metal exposures dates back to early civilizations. For example, it has been deduced that extensive mining and smelting of lead and its widespread use in the Roman Empire caused significant incidence of lead poisoning (Nriagu 1983; Hong et al. 1994). The source of metals in the environment ultimately can be traced back to their occurrence primarily in rocks, with their release to soil, water, and air facilitated by weathering processes. Consequently, the natural occurrences of metals in soils and waters are strongly correlated to the varied distribution of rock types and the compositions of the constituent minerals. More than 2000 years ago the Greek physician Hippocrates recognized relationships between disease and location, illustrating that environmental factors influenced human health. Today there are many known geographic patterns of disease that have been correlated with properties of soils or waters, or even aerosol particles. It has been difficult to demonstrate cause-effect relationships for many correlations, and efforts to relate total concentration of a metal contaminant to toxic impact have proven difficult (Davies et al. 2005). This point illustrates the essential concept that the total amount of an element in an environmental setting is not necessarily a good measure of its potential health threat. Within the last two centuries human activities have been highly effective in redistributing metals on local, regional, and even global scales. This has contributed to a greater exposure to humans. We have also changed the chemical forms of …
Acoustic angiography of tumor vascular perfusion following high intensity focused ultrasound ablation

Perfluorocarbon contrast agents, both microbubbles and nanodroplets, are known to enhance high intensity focused ultrasound (HIFU) ablation. While it is known that HIFU ablation reduces vascular perfusion in tissue these effects have not been mapped with high-resolution imaging, such as acoustic angiography. We aimed to determine the acute and chronic effects of HIFU on tumors in the presence and absence of both microbubbles and nanodroplets. Pulsed HIFU (2 MPa, 1 MHz, 10% duty cycle, 1 Hz PRF for 5 s) was delivered to flank fibrosarcoma tumors (n=9). During HIFU, 4.5×108 microbubbles or nanodroplets were infused via tail vein catheter (n=3 per group). Tumor perfusion was assessed 15 minutes and 72 hours after HIFU delivery. Only microbubbles resulted in a significant reduction in vascular perfusion (66.2±15.2%, p<;0.05). Both nanodroplets and microbubbles reduced the growth rates of tumors, although not significantly. Tumors treated with microbubbles and nanodroplets during HIFU resulted in only 121±41% and 106±47% volume increases respectively compared to 177±65% for HIFU-only treated controls. These results suggest that vascular perfusion can be drastically reduced, and tumor vasculature can be remodeled with sub-ablative HIFU. Low pressure HIFU when combined with microbubbles has the potential to enhance the safety of HIFU therapy. The acoustic angiography technique applied herein is especially applicable for determining sub-ablative effects of ultrasound and contrast agents on vascular perfusion.
An approach to the measurement of suitability for psychotherapy.

As a first step toward the measurement of the complex variable, “suitability for psychotherapy,” this essay defines this variable by a set of criteria. These criteria may be applied to content analysis of transcribed interviews; and they allow a differentiation of patients into “easy” and “difficult” candidates for psychotherapy. In the “difficult” group, patients: (1) cannot describe feelings; (2) they exhibit relationships in which the “object” is essential but is not overvalued; (3) they tend to use nonspecific pronouns; (4) they make bizarre interpretations of sensations; and (5) they display circumstantiality in their accounts of past experiences.
Photoregulation of the expression of lactate dehydrogenase isozymes in Fundulus heteroclitus (Linnaeus)

Abstract 1. 1. Fundulus heteroclitus possesses two codominant alleles, B and B ′, coding for the B-type subunits of lactate dehydrogenase (LDH) isozymes and normally expresses three LDH phenotypes, BB, BB′ and B′B′. 2. 2. In dark-adapted animals the B -locus polymorphism disappears and all individuals express identical LDH isozyme patterns. 3. 3. Apparently, lack of photo-stimulation simultaneously represses the B-locus and derepresses other loci coding for immunologically related, but electrophoretically dissimilar subunits.
Discrete scattering theory : Green's function for a square lattice

Abstract It is well known that, under certain circumstances, discrete plane waves can propagate through lattices. Waves can also be generated by oscillating one point in the lattice: the corresponding solution of the governing partial difference equations is the discrete Green’s function, g mn . The far-field behaviour of g mn is obtained using three methods: textbook derivations are corrected and a formula for g nn as a Legendre function is derived. The low-frequency behaviour of g mn is also obtained using Mellin transforms. These results are useful in the development of a discrete scattering theory.
A pointing system design concept for Space Station attached payloads

A study has been conducted to recommend a pointing system design and architecture that can accommodate the articulated pointing requirements levied on the Space Station Freedom Attached Payload Pointing System. A conceptual design of a control system is developed using classical rate and position control techniques. A high fidelity simulation testbed has been developed as the principal tool for the pointing performance evaluation. Techniques of model reduction are applied to reduce the model order to a manageable size for incorporation into the testbed. The disturbance rich space station environment has been modeled, and nonlinearities such as bearing friction, motor and sensor noise are also considered. Simulations were performed with representatie payloads at nominal pointing orientations. The results show that the tight instrument pointing requirements and the severe Space Station disturbance environment render a marginal performance for a conventional (direct drive and hardmount) gimbal pointing system, particularly for lightweight payloads. A gimbal system that incorporates a passive base isolator and reactionless actuation appears to provide a significant imporvement in pointing performance over the conventional pointing systems.
Pharmacokinetics of Buspirone Extended-Release Tablets: A Single-Dose Study

The objective of this study is to evaluate the absorption of buspirone and its biotransformation to 1-(2-pyrimidinyl) piperazine (1-PP) from two different extended-release (ER) formulations of buspirone HCl tablets (12-hour and 24-hour in vitro release) and from a commercially available immediate-release (IR) tablet. A single dose of the 30 mg ER tablets was compared with two doses of the 15 mg IR tablet administered 12 hours apart. Eighteen healthy male subjects participated in this randomized, open-label, three-treatment crossover study. Blood samples were obtained at 22 time points from predose (0 hour) until 36 hours postdose, and plasma concentration of buspirone and 1-PP was determined by LC/tandem mass spectrometry method. The pharmacokinetic parameters AUC0-t, AUC0-infinity, Cmax, tmax, Ke, and t1/2 were calculated and statistically analyzed. The results indicated extended release of buspirone from the two test products in vivo with a 70% to 90% greater bioavailability in comparison with the IR formulation. The bioavailability of 1-PP from ER formulations appears to be equal to that from the IR formulation. Both buspirone ER tablets successfully delivered bioavailable buspirone with a reduction in peak drug and metabolite plasma levels, prolonged buspirone plasma concentrations, and decreased ratio of 1-PP to buspirone concentration with less intersubject variation when evaluated as a single-dose study in healthy human subjects.
Comparison of PPVT-R and WISC-R in a mild/moderate handicapped sample.

The Peabody Picture Vocabulary Test—Revised, Form L was compared with the Wechsler Intelligence Scale for Children—Revised with a sample of 32 mild/moderate handicapped students (24 boys, 8 girls)....
Automatic generation of high coverage usability tests

Software systems are often complex in the number of features that are available through the user interface and consequently, the number of interactions that can occur. Such systems are prone to errors when interactions do not work as anticipated. This research introduces a combinatorial method for setting up task-based usability tests. The method bridges contributions from mathematics, design of experiments, software test, and algorithms for application to usability testing.
A phase I trial of sorafenib plus gemcitabine and capecitabine for patients with advanced renal cell carcinoma: New York Cancer Consortium Trial NCI 6981.

OBJECTIVE: To define the safety [dose limiting toxicity (DLT)] and recommended phase II dose of the combination of sorafenib plus gemcitabine and capecitabine for advanced renal cell carcinoma (RCC). METHODS: In this phase I dose-escalation study, cohorts of 3 to 6 patients with metastatic RCC received sorafenib (200 or 400 mg po BID), gemcitabine (750 or 1000 mg/m(2) intravenous on days 1 and 8), and capecitabine (415 or 622 mg/m(2) po BID days 1-14) every 21 days using a standard 3+3 design. RESULTS: Fifteen patients with advanced RCC (93% with clear cell histology and 87% treatment naive) received treatment. The recommended phase II doses for the combination were sorafenib 200 mg/m(2) BID continuously plus gemcitabine 750 mg/m(2) intravenous days 1 and 8 and capecitabine 415 mg/m(2) BID days 1 to 14, every 21 days. Of the 15 patients, 3 developed dose-limiting hand-foot syndrome during the first 2 cycles; 2 additional DLT's were grade 3 mucositis and transaminase elevation. Four of 14 evaluable patients had a partial response by response evaluation criteria in solid tumors (29%; 95% confidence interval (CI): 8, 58%). Median progression-free survival was 7.5 months (95% CI-0, 18.7), and median overall survival has not been reached at a median follow-up of 28.8 months. The median number of treatment cycles given was 7 (range, 2-38+). CONCLUSIONS: The combination of sorafenib plus gemcitabine and capecitabine is tolerable, but requires attenuation of sorafenib and capecitabine dosing because of the overlapping toxicity of hand-foot syndrome. Antitumor activity was observed leading to an ongoing phase II trial.
THE REDSHIFT EVOLUTION OF QSO HEAVY ELEMENT ABSORPTION SYSTEMS

Recent results on the evolution of various classes of QSO heavy element absorption line systems are summarized. A general scenario for interpreting the observed evolution is suggested, with emphasis on the implications for the evolution of gas in galaxies from z=4 to the present.
Nasopharyngeal Branchial Cysts—Diagnosis and Management: A Case Series

Nasopharyngeal branchial cysts (NBCs) have been discussed in the literature in only a limited number of publications. Differing from Tornwaldt cysts, NBCs present laterally and arise from the fossa of Rosenmuller and may track superiorly within the bony confines of the Eustachian tube. Initially patients are asymptomatic but may present with aural fullness, unilateral conductive hearing loss, and serous otitis media as the cyst mass grows. Two of our three patients had the lesion incidentally identified at the time of assessment for another diagnosis. In this case series, imaging characteristics and response to treatment are reviewed. A literature search was performed to summarize the management options for this entity.
Modulation of fibronectin, laminin, and cellular adhesion in the transformation and differentiation of murine AKR fibroblasts

The functional relationship between membrane/cell surface expression of fibronectin and laminin and transformation/differentiation was examined in an AKR mouse fibroblastic cell model. This model consisted of the untransformed AKR-2B cells, their chemically transformed counterpart (AKR-MCA cells) and the chemically differentiated from of the AKR-MCA cells. The transformed AKR-MCA cells were found to express more surface laminin and less fibronectin than the untransformed AKR-2B cells. The transformed AKR-MCA cells were slower to attach and spread on both plastic and type IV collagen-coated dishes in comparison of the AKR-2B cells. However, a higher percentage of the AKR-MCA cells ultimately attached and spread on the type IV collagen-coated dishes. The induction of differentiation in the AKR-MCA cells by N, N-dimethylformamide (DMF) restored fibronection to the surface of the AKR-MCA cells but reduced laminin expression only slightly. The DMF-treated AKR-MCA cells resembled the AKR-2B cells in that they rapidly attached and spread on plastic dishes and dishes coated with type IV collagen. They also resembled the AKR- MCA cells in that a high proportion ultimately attached and spread on the collagen-coated dishes.
MDA435/LCC6 and MDA435/LCC6MDR1 : ascites models of human breast cancer

We have established a novel ascites tumour model (MDA435/LCC6) from the oestrogen receptor-negative, invasive and metastatic MDA-MB-435 human breast cancer cell line. MDA435/LCC6 cells grow as both malignant ascites and solid tumours in vivo in nude mice and nude rats, with a tumour incidence of approximately 100%. Untreated mice develop ascites following i.p. inoculation of 1 x 10(6) cells and have a reproducible life span of approximately 30 days, with all animals dying within a 48 h period. The in vivo response of MDA435/LCC6 ascites to several cytotoxic drugs, including doxorubicin, etoposide (VP-16), BCNU and mitomycin C, closely reflects the activity of these single agents in previously untreated breast cancer patients. MDA435/LCC6 cells also retain the anchorage-dependent and anchorage-independent in vitro growth properties of the parental MDA-MB-435 cells, and can be used in standard in vitro drug screening assays. The drug resistance pattern of the MDA435/LCC6 cells suggests that they may have few active endogenous drug resistance mechanisms. To generate a model for the screening of MDR1-reversing agents, MDA435/LCC6 were transduced with a retroviral vector directing the constitutive expression of the MDR1 cDNA, producing a cell line with a classical MDR1 resistance pattern (MDA435/LCC6MDR1). THese ascites models may be a viable alternative to the murine leukaemia ascites (L1210, P388) and, in conjunction with other breast cancer cell lines, facilitate the in vitro and in vivo screening of new cytotoxic drugs and drug combinations.
Vapor phase surface preparation (etching) of 4H–SiC substrates using tetrafluorosilane (SiF4) in a hydrogen ambient for SiC epitaxy

Abstract Tetrafluorosilane (SiF 4 ) was demonstrated to be a good etchant of SiC substrates. Etch rates of silicon carbide (SiC) substrates using SiF 4 +H 2 , SiCl 2 H 2 (DCS)+H 2 , and C 3 H 8 +H 2 (at typical SiC growth conditions) were compared to the etch rates found using only H 2 . While H 2 is responsible for C removal, we find that the SiC etch rate is limited by the Si removal rate, leading to liquid Si on the SiC surface. By using propane to prevent Si-droplet formation, the etch rate is significantly reduced to −1 . SiF 4 enhances Si removal from the surface through the formation of SiF 2 gas, resulting in an improved liquid Si-free surface with r.m.s. roughness 0.45 nm and etch rates as high as 43 µm h −1 . Weak off-cut dependency was observed for SiF 4 etching. At high etch rates (>15 µm h −1 ) the etching becomes more isotropic in the SiC kink and step directions, leading to increased step bunching by the Schwoebel effect. DCS was found to be an ineffective etchant, depositing significant amounts of Si on the surface of SiC (~1–23 µm h −1 ), despite the fact that SiCl 2 is a volatile species at this temperature. These differences were explained by comparing Gibbs free energies for various Si-removal pathways.
Regulation of acetylcholinesterase appearance at neuromuscular junctions in vitro

The appearance of acetylcholinesterase (AChE) at newly formed nerve–muscle synapses depends on synaptic transmission. Synapses form when cultures are grown in the presence of acetylcholine receptor antagonists, but AChE does not accumulate at these synapses. The important component of transmission seems to be muscle activity. Treatment with dibutyryl cyclic GMP mimics muscle activity, directly inducing synaptic AChE appearance.