cssi/SciSciGPT-SciSciNet huggingface dataset:
Developing a project-based curriculum for the design and analysis of algorithms for intractable problems

In Computer Science, problems for which no fast algorithms are known are called intractable. The class of NP-complete problems is an important collection of intractable problems. The need to solve intractable problems arises in numerous practical settings. However, the only algorithms that are known to solve these problems at the present time require an exponential amount of time. In recent years, algorithm designers have focused their attention on feasible techniques for solving these problems such as approximate algorithms, probabilistic algorithms, and others. Approximate algorithms will compute a sub-optimal solution that is guaranteed to be within a factor of the optimal solution. Probabilistic algorithms may only guarantee that a solution will be found with a certain probability. These algorithms can be used to develop software programs that solve some instances of intractable problems. As computers have continued to become more powerful and affordable, the computing power available in industry and research is increasingly sufficient to run these solvers on useful, often large, instances of some intractable problems.
Computed Tomography Guidance for Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia.

BACKGROUND Percutaneous glycerol rhizotomy (PGR) is a well-described treatment for trigeminal neuralgia; however, the technique in using surface landmarks and fluoroscopy has not drastically changed since being first introduced. In this paper, we describe a protocol for PGR using computed tomography (CT) guidance based on an experience of over 7 yr and 200 patients. OBJECTIVE To introduce an approach for PGR using CT guidance and, in doing so, demonstrate possible benefits over the traditional fluoroscopic technique. METHODS Using a standard CT scanner, patients are placed supine with head in extension. Barium paste and a CT scout image are used to identify and plan a trajectory to the foramen ovale. A laser localization system built into the CT scanner helps to guide placement of the spinal needle into the foramen ovale. The needle position in the foramen is confirmed with a short-sequence CT scan. RESULTS CT-guided PGR provides multiple benefits over standard fluoroscopy, including improved visualization of the skull base and significant reduction in radiation exposure to the surgeon and staff. Side benefits include improved procedure efficiency, definitive imaging evidence of correct needle placement, and potentially increased patient safety. We have had no significant complications in over 200 patients. CONCLUSION CT-guided PGR is a useful technique for treating trigeminal neuralgia based on better imaging of the skull base, better efficiency of the procedure, and elimination of radiation exposure for the surgeon and staff compared to traditional fluoroscopic based techniques.
Trembr: Exploring Road Networks for Trajectory Representation Learning

In this article, we propose a novel representation learning framework, namely TRajectory EMBedding via Road networks (Trembr), to learn trajectory embeddings (low-dimensional feature vectors) for use in a variety of trajectory applications. The novelty of Trembr lies in (1) the design of a recurrent neural network--(RNN) based encoder--decoder model, namely Traj2Vec, that encodes spatial and temporal properties inherent in trajectories into trajectory embeddings by exploiting the underlying road networks to constrain the learning process in accordance with the matched road segments obtained using road network matching techniques (e.g., Barefoot [24, 27]), and (2) the design of a neural network--based model, namely Road2Vec, to learn road segment embeddings in road networks that captures various relationships amongst road segments in preparation for trajectory representation learning. In addition to model design, several unique technical issues raising in Trembr, including data preparation in Road2Vec, the road segment relevance-aware loss, and the network topology constraint in Traj2Vec, are examined. To validate our ideas, we learn trajectory embeddings using multiple large-scale real-world trajectory datasets and use them in three tasks, including trajectory similarity measure, travel time prediction, and destination prediction. Empirical results show that Trembr soundly outperforms the state-of-the-art trajectory representation learning models, trajectory2vec and t2vec, by at least one order of magnitude in terms of mean rank in trajectory similarity measure, 23.3% to 41.7% in terms of mean absolute error (MAE) in travel time prediction, and 39.6% to 52.4% in terms of MAE in destination prediction.
Improved Environmental DNA Reference Library Detects Overlooked Marine Fishes in New Jersey, United States

An accurate, comprehensive reference sequence library maximizes information gained from eDNA metabarcoding of marine fishes. Here we used a regional checklist and early results from an ongoing eDNA time series to target mid-Atlantic U.S. coastal fishes lacking reference sequences. We obtained 60 specimens representing 31 species from NOAA trawl surveys and institutional collections, and analyzed 12S and COI barcode regions, the latter to confirm specimen identification. Combined with existing GenBank accessions, the enhanced 12S dataset covered most (74%) of 341 fishes on New Jersey State checklist including 95% of those categorized abundant or common. For eDNA time series, we collected water samples approximately twice monthly for 24 months at an ocean and a bay site in New Jersey. Metabarcoding was performed using separate 12S primer sets targeting bony and cartilaginous fishes. Bioinformatic analysis of Illumina MiSeq fastq files with the augmented library yielded exact matches for 90% of the 104 fish amplicon sequence variants generated from field samples. Newly obtained reference sequences revealed two southern U.S. species as relatively common warm season migrants: Gulf kingfish (Menticirrhus littoralis) and Brazilian cownose ray (Rhinoptera brasiliensis). A beach wrack specimen corroborated the local presence of Brazilian cownose ray. Our results highlight the value of strengthening reference libraries and demonstrate eDNA can help detect range shifts including for species overlooked by traditional surveys.
Hidden variation: cultivars and wild plants differ in trait variation with surprising root trait outcomes

Restoration practitioners have many seed material choices when restoring plant communities, and cultivars may be the most affordable and accessible material available for some species. However, the process of plant selection and commercial seed production can limit trait variability critical to survival and persistence in heterogeneous environments. Several studies show the impacts of plant selection and commercial production on trait values and variation in aboveground traits. Yet, researchers rarely assess impacts on root traits in wild‐collected material relative to cultivars. This is a critical gap, especially in arid environments where root traits play key roles in plant survival. We grew Pseudoroegneria spicata seedlings from three wild accessions and three cultivars (the cultivars “Whitmar” and “Goldar,” and the “selected germplasm polycross” “P‐7”) to compare root and shoot traits and variability. We grew seedlings in a growth chamber for 4 weeks in sand, which had low moisture content and few added nutrients, resulting in stressful conditions. We harvested the plants and compared trait variation and averages between wild‐collected versus cultivars for four shoot and four root traits. We found that wild accessions had marginally greater variation in root tip count, root mass fraction, and shoot mass fraction. Importantly, wild‐collected plants had 51% more root tips on average, greater variability in four of seven traits that exhibited differing variability between collection types, and greater survival compared to cultivars. These results indicate differences in traits and variation in wild and cultivated accessions that should be considered when choosing material for restoration use.
Abstract P781: Ischemic Postconditioning Protects Against Hemorrhagic Transformation Induced by Hyperglycemia in Ischemic Stroke

Background: Hyperglycemia occurs in over 40% of ischemic stroke patients, which induces hemorrhagic transformation (HT) and worsens stroke outcomes. The management of hyperglycemia with insulin did...
Optimization algorithms for parameter identification in parabolic partial differential equations

The problem of estimating model parameters from data representing near-equilibrium patterns in PDEs is considered. This problem is formulated as an optimization problem by determining the nearest state on a manifold of equilibria. Algorithms to solve this optimization problem are proposed, by first regularizing the problem and using explicit search directions on the tangent space of the equilibrium manifold. Some rigorous results on local converge are obtained. Several examples of pattern forming systems are used to test the proposed methodology. Comparisons to synthetic data are made showing the ability of obtaining excellent estimates even when significant noise is present.
Liver Granulocytic Sarcoma With Megakaryocytic Differentiation: A Rare Extra Medullary Involvement That Warrants Liver Biopsy for Prompt Diagnosis.

Granulocytic sarcoma (GS) is an extramedullary manifestation of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) or myeloproliferative neoplasms. The diagnosis depends on morphology, immunohistochemistry and flow cytometry. An unusual location of this tumor may mask its primary source, therefore, a strategy involving immediate symptom control, and investigation is crucial in preventing clinical deterioration. We present a case of a 53-year-old man who initially presented with tumor lysis syndrome and transaminitis, with a subsequent CT Scan that revealed multiple liver lesions. This case describes a rare clinical entity of granulocytic sarcoma as multiple hypoattenuating liver lesions mimicking metastatic disease in its radiographic appearance. Since the imaging features of hepatic masses are nonspecific, and considering the aggressive nature of AML with concomitant tumor lysis syndrome, a confirmatory prompt biopsy should routinely be considered.
Perioperative Neurologic Outcomes of Right vs. Left Upper Extremity Access for Fenestrated-Branched Endovascular Aortic Aneurysm Repair (F-BEVAR)

Objective Upper extremity (UE) access is frequently used for F-BEVAR, particularly for complex repairs. Traditionally, left-side UE access has been used to avoid crossing the arch and the origin of the supra-aortic vessels, which could potentially result in cerebral embolization and an increased risk of perioperative cerebrovascular events. More recently, right UE has been more frequently used as it is more convenient and ergonomic. The purpose of this study was to assess the outcomes and cerebrovascular events after F-BEVAR with the use of right vs. left-side upper extremity access. Methods During an 8-year period, 453 patients (71% male) underwent F-BEVAR at a single institution. UE access was used in more complex repairs. Left UE access was favored in the past, whereas right UE access is currently the preferred UE access side. Brachial artery cutdown was used in all patients for the placement of a 12F sheath. Outcomes were compared between patients undergoing right vs. left UE access. Endpoints included cerebrovascular events, perioperative mortality, technical success and local access related complications. Results UE access was used in 361 (80%) patients. The right-side was used in 232 (64%) and the left-side in 129 (36%) patients for the treatment of 88 (25%) juxtarenal, 135 (38%) suprarenal and 137 (38%) thoracoabdominal aortic aneurysms. Most procedures were elective (94%). Technical success was achieved in 354 patients (98%). In-patient or 30-day mortality was 3.3%. Five (1%) perioperative strokes occurred in patients undergoing right UE access, of which 3 were ischemic and 2 were hemorrhagic. No transient ischemic attacks (TIAs) occurred perioperatively. Two hemorrhagic strokes were associated to permissive hypertension to prevent spinal cord ischemia. No perioperative strokes occurred in patients undergoing left UE access (P=.16). Overall, perioperative strokes occurred with similar frequency in patients undergoing UE (5, 1%) and femoral access only (1, 1%) (P=.99). Arm access related complications occurred in 15 (5%) patients, 11 (4.8%) on the right-side and 4 (6%) on the left-side (P=.74). Conclusions Right upper extremity access can be used for F-BEVAR with low morbidity and minimal risk of perioperative ischemic stroke or TIAs. In general, upper extremity access is not associated with an increased risk of perioperative stroke compared to femoral access only. Tight blood pressure control is, however, critical to avoid intracranial bleeding related to uncontrolled hypertension.
Incidence, Diagnosis and Treatment of Broad Ligament Fibroids in Women Undergoing Minimally Invasive (MIS) Myomectomy: A Chart Review

Study Objective The incidence of broad ligament fibroids is reported to be approximately 1% in the literature, however based on our surgical population, we propose that the incidence is much higher. Broad ligament fibroids are commonly misdiagnosed on preoperative MRI imaging. We aim to determine preoperative imaging characteristics that suggest a diagnosis of broad ligament fibroid. We aim to determine the true incidence of broad ligament fibroids in women undergoing MIS myomectomy at a single institution. Design Retrospective chart review was performed to identify preoperative imaging, operative reports, and postoperative data in the acute postoperative period (10 weeks following surgery). Setting N/A. Patients or Participants Patients were identified for inclusion via review of the surgical schedule during the study period (January 2018 – December 2020). Women ≥18 years-old undergoing MIS myomectomy were eligible for inclusion. 227 patients were identified for inclusion and chart review. Interventions N/A. Measurements and Main Results A total of 27 (11.9%) patients were identified to have a broad ligament fibroid at the time of surgery. One additional patient was identified in whom the fibroid had significant adhesions to the broad ligament but did not arise from the broad ligament itself. No patients had preoperative imaging correctly identifying the location of the fibroid as within the broad ligament. Complications included pelvic sidewall hematoma (1), thermal colon injury (1), postoperative hypotension (1), incisional hernia (1), readmission for hemoperitoneum (1), reoperation for hemoperitoneum (1), incisional cellulitis (1), and unexpected salpingo-oophorectomy secondary to adhesions (1). Conclusion The 11.9% incidence reported here is significantly higher than previously reported. Correct preoperative diagnosis is exceedingly rare, making accurate surgical counseling difficult. A goal of gynecologic imaging should be to identify common characteristics of broad ligament fibroids on MRI imaging because such patients can have increased rates of complications after MIS myomectomy. Accurate imaging and preoperative diagnosis are critical for proper surgical counseling, planning and intraoperative management.
Automated Prediction of Voter’s Party Affiliation Using AI

The goal of this research is to develop the foundation of a cross-platform app, Litics360, that helps political election campaigns utilize data-driven methods, and high-performance prediction models, to align candidates with voters who share similar socio-political ambitions. To attain this goal, the first step is to understand a voter’s currently aligned political party affiliation, based primarily on historical records of their turnout at previous elections, and basic demographic information. This chapter aims to find a solution to this first step, by comparing varied performance measures to find a reliable prediction model from learning algorithms, including decision tree, random forest, and gradient boosting machine XGBoost binary classifiers. Significant correlations between independent variables and the target prediction class, i.e., voter’s registered party affiliation, contribute toward the development of an automated predictive ML model. The Ohio Secretary of State public voter database was used to collect voter demographics and election turnout data, then prepared using preprocessing methods, and finally used to identify the best performing ML model. Hyperparameter grid search with XGBoost proved to be the superior binary logistic classifier, reproducing a nearly perfect skillful model. Tracking the alignment between voters and PEC candidates the proposed future of Litics360; i.e., to develop an application that promotes a healthy and transparent platform for voters to communicate their socio-political grievances to PECs, enabling efficient appropriation of a PEC’s funds and resources to engineer successful marketing campaigns.
The level of association between functional performance status measures and patient-reported outcomes in cancer patients: a systematic review

Purpose The process of assessing patient symptoms and functionality using patient-reported outcomes (PROs) and functional performance status (FPS) is an essential aspect of patient-centered oncology research and care. However, PRO and FPS measures are often employed separately or inconsistently combined. Thus, the purpose of this study was to conduct a systematic review of the level of association between PRO and FPS measures to determine their differential or combined utility.
Killing Us Softly: How Sub-Theraputic Dosing of Livestock Causes Drug-Resistant Bacteria in Humans

This Note explores antibiotic-resistant bacterial strains in humans and their roots in American industrial livestock practices. Factory farms promote the growth of antibiotic-resistant bacteria—or “superbugs” —by giving animals subtherapeutic doses of antibiotics to prevent the diseases that result from confinement and unhygienic conditions. Although Congress has repeatedly attempted to pass legislation to curtail the use of subtherapeutic antibiotic dosing in livestock, those efforts have yielded little change for nearly a decade. Similarly, the Food and Drug Administration (FDA) has stood by while antibiotic-resistance in human bacteria has exploded into a critical public health issue. This Note advocates for citizen action under the Administrative Procedure Act to prompt the FDA to withdraw animal approval for antibiotics that are important to human health. A citizen petition has a greater chance of success today than in past years due to the newly available scientific data and international recognition of the dangers of the overuse of antibiotics in factory farming.
U.S. Foreign Economic Policy and the Significance of the National Economic Council

Research demonstrates that the National Economic Council (NEC) and the decision-making process through which economic issues must pass are essential components in the evolution of American foreign economic policy. This article will examine the functions and responsibilities of the NEC in the making of U.S. foreign economic policy under Presidents Bill Clinton and George W. Bush. It selects key policies, namely international monetary policy, fiscal policy, and trade liberalization, and examines key issues within each in order to provide tentative answers to questions regarding foreign economic policy and the emergence and development of the NEC. Also, this article supplies an overview of the large body of research on international economics and foreign economic policy. Furthermore, it identifies key U.S. foreign economic policy issues developed and coordinated by the NEC. The article concludes with a discussion of to what extent the NEC is a significant development in U.S. foreign economic policy and in the making of foreign policy.
StatsMonkey: A Data-Driven Sports Narrative Writer

There are certain types of stories that are often told in very structured ways; sports stories or financial reports are two examples. Readers care about these narratives because they are passionately interested in the topic and want to read about the specific details of the event. In other words, they care about the data and want to read a story that presents that data to them. However, in order to be compelling these narratives cannot merely repeat the data, rather they must tell a story from the data. In this paper, we will present a model for data-driven story-telling and discuss StatsMonkey, a system that automatically writes baseball stories from raw baseball game numerical data available online. We will show that a machine can generate interesting, readable stories and that it can make editorial decisions about what aspects of a situation to highlight. Further we will show that a machine can determine in what manner those aspects should be shared.
Only connect: Why government often ignores research

Most academic research on public policy achieves little influence in government. The disconnect reflects the different ways researchers and government learn about policy. In social policy, typically, scholars make rigorous but narrow arguments about how to improve social conditions while saying little about politics or government. Policymakers, however, reason in broader, integrative ways and pay more attention to program experience and institutions. Evaluations have influence in part because they serve the governmental style. By reasoning more like policymakers, scholars could have greater influence. But to make that connection, the teaching of public policy and academic incentives must change.
Appropriate utilization and cost control of the hospital laboratory : panel testing and repeat orders

Analysis of hospital laboratory utilization shows a bi-exponential relationship between the many different test combinations ordered and their frequency of use. This suggests two opposite strategies to reduce test volume. Policy could discourage use of the most popular request combinations to reduce volume, or policy could discourage use of the least popular request combinations to reduce order variety. Analysis of biochemical test orders further suggests that the largest part of test requests is associated with a small number of pathophysiological issues, namely those involving electrolytes, fluid balance, blood lipids, heart, liver, kidney or bone disease. Therefore, efficiency results when a limited number of standard test panels addressing these issues reduce order variety by discouraging infrequently used test combinations. Standard panels can be developed from an analysis of the most popular existing orders, accepting some degree of discrepancy among otherwise overlapping requests. This empiric approach avoids sterile debate about the composition of ideal panels. Since the resources of the laboratory, the mix of patients served and local medical tradition affect test orders, each institution providing health care must develop the standard panels best suited to its needs. Analysis of standing repeat orders suggests they are often used to anticipate potential pathology in stable patients. Therefore, economy results when test volume is reduced by discouraging series of futile repeat tests with unchanging normal results. Unfortunately, an empiric approach to regulate repeat orders is not available and only a more cumbersome process to build a locally agreed upon consensus between providers and users of laboratory services offers itself as a promising solution.
Inotropic Therapy for End-Stage Heart Failure Patients

Positive inotropic agents play an important role in the management of acute decompensated heart failure (HF) patients with reduced cardiac output and poor end-organ perfusion. However, despite their acute hemodynamic benefits, the role of inotropes in the management of chronic advanced HF remains limited. Although digoxin has demonstrated the ability to improve symptoms in HF patients, numerous small, mostly nonrandomized studies have shown that patients with advanced HF improve symptomatically when administered continuous or intermittent intravenous β-agonists or phosphodiesterase inhibitors. However, this improvement occurs at the expense of an increased risk of cardiac arrhythmias, sudden cardiac death, and mortality. Similarly, several oral inotropes have been developed and studied in larger randomized clinical trials. The PROMISE study found that oral milrinone is associated with increased mortality, whereas the ESSENTIAL study showed that oral enoximone does not result in any significant improvement in symptoms, exercise capacity, or survival. The calcium-sensitizing inotrope levosimendan has shown some promise in the management of acute HF patients, but the PERSIST trial showed no improvement in survival or hospitalization rates with chronic oral therapy. This agent is still under investigation and is not available in the United States. Istaroxime, an inotrope with lusitropic properties, is also being investigated for its potential use in advanced HF patients. The current American College of Cardiology/American Heart Association, European Society of Cardiology, and Heart Failure Society of America guidelines indicate that, other than digoxin, inotropic agents should be reserved for patients presenting with acute decompensated HF and low-output states and reduced end-organ perfusion, who typically are admitted to an intensive care unit. These agents also are of benefit in advanced HF patients as a bridge to transplantation to optimize end-organ function and may be used in the outpatient setting, usually in patients with an implantable cardioverter–defibrillator. Finally, inotropes should be used to palliate symptoms in end-stage HF patients who have severe symptoms and are not candidates for heart transplantation or mechanical circulatory support.
Evaluation of methods for the determination of halogenated hydrocarbons in air.

(1959). Evaluation of Methods for the Determination of Halogenated Hydrocarbons in Air. American Industrial Hygiene Association Journal: Vol. 20, No. 2, pp. 138-141.
Cultural Dialogue and Schooling in Schoenhausen and Roseville: A Comparative Analysis

Our study examines schooling cross-culturally by looking at two examples of school culture. We suggest that the recent movement in educational anthropology and ethnography away from cross-cultural or comparative focus to concerns with classrooms, schools, and schooling in our own society may have contributed to a blurring of focus on culture itself. We define what is meant by the study of culture and then discuss our current research in Schoenhausen, Germany and Roseville, United States (these place names are pseudonyms). Because we see education as cultural transmission, we want to look at the learning that takes place in classrooms as the result of calculated intervention. We use ethnography, the instrumental activities model, and films as evocative stimuli in reflective cross-cultural interviews.
Longing, Nostalgia, and Golden Age Politics: The American Jeremiad and the Power of the Past

I assess several politically powerful ways of drawing on the past in the search for solutions to problems in the present. To probe these dynamics, I turn to the American jeremiad, a longstanding form of political rhetoric that explicitly invokes the past and laments the nation's falling-away from its virtuous foundations. I begin by focusing on the Christian Right's traditionalist jeremiad, which offers both nostalgic and Golden Age rhetoric in its assessment of the United States' imperiled national promise. I argue that, despite differences in the historical location of their ideals and the significant rhetorical power that they bring to political life, such nostalgic and Golden Age narratives represent a constraining political ideal, one ultimately incapable of doing justice to an increasingly diverse American society. I argue furthermore that there is another strand of the American jeremiad and conclude by sketching a different way of drawing on the past, a progressive jeremiad epitomized by the thought of Abraham Lincoln and Frederick Douglass. Such a jeremiad is also deeply rooted in the American tradition and offers a far more promising contribution to a diverse and pluralistic American future.
Thymectomy in the treatment of ocular myasthenia gravis

Abstract Background: Thymectomy is an effective and accepted treatment for myasthenia gravis, but thymectomy for ocular myasthenia gravis (Osserman stage I) is controversial. Objective: To assess the efficacy and propriety of thymectomy for the treatment of ocular myasthenia gravis. Methods: We conducted a review and follow-up of all patients who had thymectomy for the treatment of ocular myasthenia gravis between 1970 and 1998 at the University of California, Davis, Medical Center, and the University of Rome, “La Sapienza,” Rome, Italy. Patient response to thymectomy was categorized as follows: cured, patients who became symptom-free and required no further medication; improved, patients who required less medication and whose symptoms were less severe; unchanged, patients whose symptoms and medications were the same; worse, patients who had more severe symptoms, needed more medication, or died. Results: Sixty-one patients (mean age 37 years; range 14–73 years) were followed up for a mean duration of 9 years (range 0.5–29 years). Ocular myasthenia gravis with mixed and cortical thymomas, stages I to IV, occurred in 12 patients, and ocular myasthenia without thymomas occurred in 49 patients. Transsternal thymectomy (n = 55) and transcervical thymectomy (n = 6) resulted in cure in 31 (51%) patients, improvement in 12 (20%) patients, no change in 16 (26%) patients, and worsening of symptoms (including 1 postoperative death) in 2 patients. Patient outcomes were statistically independent of the duration of preoperative symptoms (mean 9.5 months), patient age, or the presence or absence of thymoma. In patients with ocular myasthenia, 70% were cured or improved after thymectomy; in the subgroup of patients with ocular myasthenia and thymoma, 67% were cured or improved. Conclusion: Thymectomy is an effective and safe treatment for patients with ocular myasthenia gravis.
Nature of the emitting 3MLCT manifold of rhenium(I) (diimine) (CO)3Cl complexes

Abstract Spectroscopic investigations of four Re(NN) (CO) 3 Cl complexes (NN = 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, 1,10-phenanthroline,or 2,9-dimethyl-1,10-phenanthroline) in the 77—4 K range reveal a single 3 MLCT emitting configuration. Temperature dependences of the phosphorescence lifetimes have been analyzed in terms of a multiple state model that yields rate constants and level splittings. A model based on C 2v symmetry that depends on second-order spin-orbit coupling between dπ* configurations is proposed to rationalize the results. Implications for the well-studied Ru(NN) 2+ 3 and Os(II) (NN) 2+ 3 manifolds are discussed.
An Empirical Comparison of the Four Channel Flow Model and Adventure Experience Paradigm

The objective of this study was to conduct empirical comparisons between two models of optimal experience within an on-site whitewater kayaking setting using a modification of the Experience Sampling Method. Four concerns are examined: (1) differences in explanatory power between the four channel flow model and the Adventure Experience Paradigm, (2) convergent validity among measures used to determine conditions within these models, (3) differences among measures of perceived challenge and risk between test times of Class I-V river difficulty, and (4) differences among measures of perceived skill and competence between test times of Class I-V river difficulty. Questionnaires were administered in the Cheat River Canyon in West Virginia to 52 whitewater kayakers at eight sites of various levels of river difficulty. Data were analyzed at the experience level, rather than between subjects, using 409 experience sampling observations. Hypothesis testing, performed with statistical analyses (stepwise regression,...
Empirical analysis of current approaches to incidental findings.

Researchers in the health sciences regularly discover information of potential health importance unrelated to their object of study in the course of their research. However, there appears to be little guidance available on what researchers should do with this information, known in the scientific literature as incidental findings (IFs). The study described here was designed to determine the extent of guidance available to researchers from public sources. This empirical study was part of a larger two-year project funded by the National Human Genome Research Institute (NHGRI) to generate guidance on how incidental findings should be managed in human subjects research, especially genetics, genomics, and imaging research. We generated empirical analysis of publicly available guidance and consent forms to help guide a multidisciplinary Working Group of experts in their formulation of normative recommendations reported in this symposium.1 Specifically, we set out to determine what information was publicly available through the Internet, focusing the search on research in genetics and genomics, neuroimaging, and computed tomography (CT) colonography. This paper highlights important findings; a more detailed account will be published elsewhere.2 Results showed that there is very little public guidance available for researchers as to how to deal with incidental findings, and that the available guidance is not consistent.
Solid phase synthesis of phosphinopeptoids as transition state analog inhibitors

Abstract A procedure for preparing novel phosphinopeptoids, 1 , on a solid support is described. The key step in the synthesis includes a conjugate addition of the trivalent form of a protected aminomethylphosphinic acid ( 5 ) to a resin-bound acrylate.
Meta-iodobenzylguanidine in children

Meta-iodobenzylguanidine (MIBG) is an effective imaging agent for neuroblastoma and pheochromocytoma in children. MIBG is concentrated by the neurosecretory granules of normal and neoplastic tissues of neural crest origin. The typical normal scintigraphic uptake pattern of MIBG includes the salivary glands, lung, myocardium, liver, gastrointestinal tract, and contents of the urinary bladder. When MIBG is labeled with iodine-123 ( 123 I), the adrenal glands often are seen. The sensitivity and specificity of MIBG imaging is extremely high in both neuroblastoma and pheochromocytoma. MIBG may detect extensive bone and bone marrow involvement in neuroblastoma, in the absence of findings on bone marrow aspiration and biopsy, plain radiographs, and bone scintigraphy. MIBG labeled with 131 I has been used with moderate success in the palliation of advanced neuroblastoma and pheochromocytoma. Early therapeutic intervention in advanced neuroblastoma is promising. Current controversies in the application of MIBG include (1) 131 I versus 123 I as a label for imaging studies: Although improved image quality and reduced absorbed radiation dose are achieved with [ 123 I]MIBG imaging, is it actually more efficacious in the detection of neuroblastoma? (2) Use of bone scintgraphy in neuroblastoma: Given the small number of false-negative MIBG scans for bone involvement, can the bone scan be dropped as a routine study in the follow-up of neuroblastoma? (3) Other new imaging agents: Is there a role for labeled monoclonal antibodies, somatostatin analogs, and magnetic resonance imaging of marrow in the routine follow-up of neuroblastoma? (4) Iodine-125 MIBG therapy in neuroblastoma: Is the improved energy deposition of 125 I at extremely short range useful in the ablation of micrometastases? (5) Early therapy with MIBG in neuroblastoma: Is there a role for MIBG therapy in the initial therapeutic regimens of children with advanced neuroblastoma? Twelve years after the initial report of its use in humans, MIBG has become an important imaging agent in pediatric neural tumors, one that is used routinely and efficaciously in many centers. In the next few years we will continue to learn more about its use, particularly in the therapy of advanced neural crest tumors.
Working through theoretical tensions in contemporary archaeology: A practical attempt from southwestern Colorado

Archaeology should actively combine different paradigms to obtain a more complete understanding of the past. This paper argues for a practical combination of elements of the culture-historical, processual, and postprocessual approaches into a two-tier model. The first tierreconstructs the events of the past, using culture-historical and middle-range principles, and the secondconstructs a reflexive explanation of these events, which situates an analysis of the internal and external constraints on past human behavior within the specific theoretical and political positions of the analyst. The theoretical arguments are developed by means of an analysis of the prehistory of a segment of the mountains of southwestern Colorado.
Particle-in-cell/Monte Carlo simulation of dusty plasmas near spacecraft surfaces

The electrodynamics of particulate contamination in an ionospheric plasma near spacecraft surfaces is being investigated by a new 2D particle-in-cell (PIC) simulation. Particulate charging in the PIC simulation is treated as a collisional event and is implemented in a Monte Carlo fashion. The simulation has been applied to dusty plasmas both in an unbounded plasma and near a bounded plasma (spacecraft surface). Results from the simulation include estimates of the charge and potential structure of finite-size dust clouds. Low-density dust clouds do not perturb the electric potential of the plasma, similar to the case for isolated particulates. In high-density dust clouds, the potential forms a sheath-like structure while the charge forms a double layer on the outer boundary of the cloud. Particulates can have negative or positive charges depending on the applied surface potential, thus raising the possibility of controlling particulate contamination by controlling the spacecraft potential.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The basis of synchronization by repetitive dilution of a growing culture

Cultures of Escherichia coli have been synchronized by periodic dilution with fresh growth medium in the laboratory of Francois Kepes. When diluted by a large factor into complete test medium, the treated cultures undergo up to 12 synchronous divisions. This long term synchrony must result from an adjustment process during the periodic dilution procedure so that all cells have nearly identical biochemical properties. Robert Pritchard (University of Leicester, personal communication) suggested that this phasing would happen if the uptake of a critical nutrient was limited by the surface area of the cell during a portion of the dilution cycle. If his suggestion is valid, a general method for synchronization of almost any organism that grows exponentially and divides by binary fission into equal sized daughters should be achievable. A computer program was devised to simulate the growth of an initially asynchronous culture under periodic dilution with medium containing a single limiting nutrient. Various models of cell shape and growth were tested along with various models for the growth-limiting substrate uptake.
Direct Detection vs Heterodyning In Optical Beam Tracking

Optical spatial tracking of a laser beam can be accomplished using quadrant detector error signals obtained from either direct detection or heterodyning. In the direct detection system the received beam is focused directly on the quadrant, and error signals are generated as the beam moves over the detector. In heterodyned systems the received field is mixed with a local laser field on the quadrant detector for error generation. Expressions to evaluate angle error variance due to receiver noise are formulated. The tracking error variance depends on signal-to-noise ratio, quantum efficiency, and the slope of the loop S curve. The loop S curve is derived differently for the two cases, and its specific form is important to the overall performance analysis. Heterodyne detection receivers are less susceptible to background radiation and device noise than direct detection receivers. However, this advantage can be compensated for direct detection system by increasing the received signal power, reducing front end bandwidth, or reducing the number of spatial modes. Design considerations of the laser beam propagating in turbulent atr hphere and multi-mode results are also addressed. Degradation due to heterodyning misalignment is also considered. The results of the study allow direct comparison of both system as possible beacon tracking subsystems. Curves will be shown to relate the key parameter that will determine which method is the most advantageous.
Failure of single dose methotrexate followed by citrovorum factor in nonmetastatic gestational trophoblastic neoplasia

With increasing cost of medical care, newer methods of administering chemotherapy on an outpatient basis are being sought to reduce the need for hospitalization and protracted losses of valuable time for patients with nonmetastatic gestational trophoblastic neoplasia (NMGTN). To achieve this end, two NMGTN patients were treated with a single course of one dose of methotrexate (MTX) followed by multidose Citrovorum Factor (CF) without observing the expected response. Failure to respond appeared to be due to the schedule of administration. Although the dose and plasma concentrations of MTX were considered to be adequate for cell kill, fractionation--as established by conventional schedules of MTX administration--appeared necessary for response by exposing the maximum number of trophoblastic cells to inhibitory levels of MTX during the S-phase of the cell cycle.
Durability and Failure Analyses of a Silane Treated Alpha-A1203/Polyethylene Joint in Wet Environment.

The durability of the joints, consisting of α-Al2O3 primed with γ-aminopropyl triethoxysilane (γ-APS) and polyethylene (PE), in wet environment is investigated as a function of the γ-APS thickness, dehydration of γ-APS prior to joint formation and redrying the joint after a certain exposure. The joint strength measured by 180°s peel is found to decrease with exposure time in wet environment more rapidly in water than in 100 percent RH. With exposure time, the debonded area increases from the edges toward the central area of the joint. Relatively thin γ-APS treatments on α-Al2O3 appear to provide a more durable joint than thicker γ-APS treatments resulting in an optimal thickness in the range of 0.3 ∼ 1 percent γ-APS concentration level. Dehydration of γ-APS leads to more durable joints with an optimal condition found between 1 ∼ 2 days of dehydration at 100°C in vacuum. Regardless of the γ-APS thickness and dehydration history, the failure in the de-bonded area seems to occur by the hydrolysis of γ-APS near the α-Al2O3 side and by the deformation of polyethylene (cohesive failure) in the peeled area, as characterized by SEM and ESCA. The debonded area in the dried joint recovers little strength, but in the central bonded areas, the strength is mostly recovered, characterized by cohesive failure of polyethylene. Diffusion of water in γ-APS near the α-Al2O3 side rather than the PE side can explain at least qualitatively most of the observed trends. The effects of γ-APS thickness and dehydration on the durability in wet environments are compared with those on adhesion promotion in dry environments as well as on their respective failure mode.
Real-time combining of optical array signals

The results of field experiments designed to demonstrate key enabling concepts of optical array receivers are presented, in a field environment similar to actual operating conditions. The theoretical framework and analytical evaluation of optical array receivers have been developed and documented in previous articles. This article describes the implementation and field evaluation of a two-element optical array receiver incorporating photon-counting, signal conditioning, high-speed digital sample distribution, adaptive delay compensation and sample combining operations required for array reception of intensity-modulated optical pulse-position modulated (PPM) signals. Data collected in the field was processed offline to determine communications performance of a two-element optical array, and demonstrate the inherent advantages of optical array reception.
Fatalities following allergen immunotherapy.

Allergen immunotherapy has been in use for nearly 100 yr and has become an important method of reducing allergic symptoms in select patients with allergic rhinitis, asthma, and insect venom hypersensitivity. Unfortunately, immunotherapy has been associated with anaphylaxis and death. Although the relative risk of severe reactions to immunotherapy is low, the number of such reactions has increased since the introduction of standardized and more potent extracts. There are a number of risk factors associated with such severe anaphylactic reactions. Such risk factors include errors in dosage, failure to reduce the dosage after a longer than scheduled interval, administration of the wrong extract, inadvertent intravenous administration, failure to postpone injection because of infection or asthma exacerbation, failure to observe patients for appropriate length of time, failure to adhere to guidelines for established contraindications, concurrent use of β-adrenergic blocking agents, uses of mixtures of allergens, immunotherapy during the active allergy season, and types of allergens. In this review, we focus on these and other risk factors in attempts to reduce the risk of anaphylaxis following allergen immunotherapy.
Production of φ , ψ , and charmed hadrons in strong interactions

It is shown that an SU(4) quark-gluon model is a specific realization of a scaling rule proposed by the authors for understanding hadronic production of heavy particles, including the recently discovered psi particles. The model leads to predominantly associated production of phi and psi (e.g., pairs). It is emphasized that tests of the charmonium picture for psi particles can be made independently by looking to see whether phi mesons are predominantly associatively produced. (AIP)
A comparison of object oriented simulation languages (abstract)

A network computer system was simulated as a single server queuing system using several computer languages including two object oriented languages. An initial simulation using Smalltalk-V was implemented on a Mackintosh II microcomputer. A procedure oriented Pascal program was then implemented on the Mack II machine. A HP Vectra PC was then used to implement the same problem in Pascal, with and without an object oriented option on Turbo Pascal 5.5.The programming was performed by two undergraduate computer science students with considerable programming experience, but who were using object oriented concepts for the first time. Developing the model of the network system to be simulated and implementing it in an object oriented language took several weeks. However, once the task was complete, implementing the model in the three other methods described was fairly simple.Both students found that using an object oriented system in a programming environment supplied by Smalltalk V was a little different than programming in a procedure oriented language such as Pascal. Once they became familiar with the Smalltalk environment, they both felt that they would prefer to develop simulation systems in Smalltalk.The code lengths of the programs were each about 500 lines, with Smalltalk V being somewhat less and Turbo Pascal 5.5 somewhat more. Run times were significantly different, however. Smalltalk-V run time for 10 replications of the simulation was 2.7 minutes, with structured Pascal taking 5.5 minutes, each on the Mack II microcomputer. Structured Pascal took 1.5 minutes on the HP Vectra, but Turbo 5.5 took 36 minutes. If this same ratio of times applies (i.e., the HP Vectra being 5.5/1.5 time as fast as the Mack II), then we would expect object oriented Turbo 5.5 to take 132 minutes to run on the Mack II. At least we found that the object oriented approach can be either faster or slower than a structured approach.