cssi/SciSciGPT-SciSciNet huggingface dataset:
Aggregation kinetics of nanosized activated carbons in aquatic environments

Abstract Nanosized activated carbons (NACs) are emerging as a new class of engineered nanomaterials, but their colloidal stability governing the fate and transport in aquatic environments has not yet been evaluated. We have characterized four representative NAC materials and examined their colloidal stability and early-stage aggregation kinetics under various water chemistry conditions. The results showed that these NAC particles had intensity-weighted hydrodynamic diameters (Dh) and number-weighted averaged diameters (Dn) of approximately 200 and 100 nm, respectively, and that their aggregation kinetics exhibited both reaction- and diffusion-limited regimes in the presence of monovalent (NaCl) or divalent (CaCl2) salt with distinct critical coagulation concentrations (CCC), indicating that their colloidal stability under the tested aqueous conditions was consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The fitting of the aggregation kinetics with predictions based on DLVO theory yielded the Hamaker constant of 2.1–2.7 × 10−20 J (ACWC, aqueous medium). The study demonstrated that NACs may be relatively stable under typical freshwater chemistry conditions, suggesting their potential applications as reactive agents for remedy of contaminated water and soil systems where long-time suspension of introduced particles is desired. The observed strong colloidal stability may also indicate high possibility of NACs being nanosized pollutants in natural and engineered environmental systems.
Bacteriological Quality of Selected Delicatessen Foods

Warm and cold delicatessen foods were purchased from local retail stores and were subsequently analyzed for total plate counts, Staphylococcus aureus and coagulase positive staphylococci, Clostridium perfringens, and coliforms. Foods were analyzed immediately after purchase, after holding 3 h at 37 C, and after holding at 9 C for 4 days. The total viable bacteria, staphylococci, coliform, and C. perfringens numbers did not vary much during storage at 37 C for 3 h and 4 days at 9 C. The average total count was 350,000 cells per gram for all foods examined. More than 30% of the staphylococcal colonies tested were coagulase positive. Meat salads contained the highest total counts and warm meats contained the lowest numbers of cells.
"Better Than Bank Robbery": Yuezi Centers and Neoliberal Appeals to Market Birth Tourism to Pregnant Chinese Women.

“Birth tourism” has rarely been addressed by scholars. The ways that pregnant women are encouraged to leave their homelands and give birth abroad have not been investigated. Birth tourism agencies ...
Immanuel Kant – Justice as Freedom

After a short explanation of Kant’s distinction between right (justice) and virtue (ethics), I sketch his theory of “private right,” which are the rights individuals have in relation to each other. Subsequently, I address the question of why we have states and public legal-political systems, followed by the issue of states’ rights (public right), specifically, the question of whether the state has (public) rights that extend beyond the (private) rights individuals have in relation to each other. The final two parts of this introduction focus on the distinction between “active” and “passive citizens,” the relation between right (justice) and politics, the issue of global justice, and, briefly, the historical influence of Kant’s ideas about justice.
Elevated intrabolus pressure identifies obstructive processes when integrated relaxation pressure is normal on esophageal high-resolution manometry

Integrated relaxation pressure (IRP) above the upper limit of normal defines esophageal outflow obstruction using high-resolution manometry. In patients with normal IRP, elevated intrabolus pressur...
Data provenance assurance in the cloud using blockchain

Ever increasing adoption of cloud technology scales up the activities like creation, exchange, and alteration of cloud data objects, which create challenges to track malicious activities and security violations. Addressing this issue requires implementation of data provenance framework so that each data object in the federated cloud environment can be tracked and recorded but cannot be modified. The blockchain technology gives a promising decentralized platform to build tamper-proof systems. Its incorruptible distributed ledger/blockchain complements the need of maintaining cloud data provenance. In this paper, we present a cloud based data provenance framework using block chain which traces data record operations and generates provenance data. We anchor provenance data records into block chain transactions, which provide validation on provenance data and preserve user privacy at the same time. Once the provenance data is uploaded to the global block chain network, it is extremely challenging to tamper the provenance data. Besides, the provenance data uses hashed user identifiers prior to uploading so the blockchain nodes cannot link the operations to a particular user. The framework ensures that the privacy is preserved. We implemented the architecture on ownCloud, uploaded records to blockchain network, stored records in a provenance database and developed a prototype in form of a web service.
Meaning Engendering Environments

Finding solutions to problems prevailing in real life situation is the transactional environment of a human adaptive control organism. In this environment, the clients approach to problem-solving should be modeled and thus enhanced by the helping professional. Episodic information processing involves helpful interactions in the statement of information requirements and in the search Process. The sequential information processing has the goal of integrating and functioning of the self, based on the patrons capacity to process any integrate environment. Professional librarians' role as a learning consultant to client (readers), particularly in articulating his information needs, is discussed. Highlights that the techniques of subject analysis and suggsets that the construction of subject catalogue should be based on models close to the real life information-processing.
Unemployment shocks for individuals on the margin: Exploring recidivism effects

Abstract This paper analyzes the impact of unemployment on the likelihood of returning to criminal activity for a sample of individuals with criminal records who are actively seeking employment. I use administrative data from the New York State Division of Criminal Justice Services, Department of Labor, and Department of Health, to track unemployment and arrest outcomes for this sample between 2008 and 2014. To identify the unemployment–arrest relationship, I use industry-specific variation in unemployment trends caused by the recession in 2008–2009, along with individual fixed effects to control for time-constant individual heterogeneity. The 2SLS estimates suggest that increased unemployment has large effects on rearrests for individuals with criminal records who are now active in the labor market, with substantial heterogeneity by race and sex. The results suggest larger estimates than those typically found in literature, indicating that targeting employment programs at those “on the margin” could substantially reduce rearrest rates for such individuals.
Length, Body Depth, and Gape Relationships and Inference on Piscivory Among Common North American Centrarchids

Species of Centrarchidae are major components of inland fisheries in much of North America. Thus, information gained from the assessment of interspecies interactions and/or quantifying predator-prey relationships is a useful tool for fisheries managers. Using preserved fish specimens (n = 717) from 20 species of centrarchids, we made measurements of total length (TL), standard length (SL), horizontal gape, and body depth for each individual. We fitted mathematical models that included horizontal gape and body depth as functions of TL and SL, and TL as a function of SL. Linear-regression-model fits were generally good (r2 = 0.764-0.998) for all 20 species, with 61 of 78 possible models having r2 values exceeding 0.90. Horizontal gape–SL (F3,702 = 77.18, P < 0.001) and body depth-SL (F3,702 = 91.79, P < 0.001) ratios differed significantly along a gradient that reflected the species' likelihood of piscivory. Slopes of TL–SL regressions did not vary by species, which enabled development of a generalized TL–SL model for centrarchids. Supplemental analyses supported that morphometric measurements had not been influenced significantly by preservation. Results of this study are useful to fisheries managers involved with understanding species interactions within centrarchid-dominated food webs, which are of high priority in most fisheries-management plans.
Crash and Near-Crash Risk Assessment of Distracted Driving and Engagement in Secondary Tasks: A Naturalistic Driving Study:

Distracted driving behavior is a perennial safety concern that affects not only the vehicle’s occupants but other road users as well. Distraction is typically caused by engagement in secondary task...
Quantum-Informed Multiscale M&S for Energetic Materials

Abstract A nonempirical, physics-based modeling and simulation (M&S) capability for energetic materials can only be obtained within a multiscale M&S framework that has a quantum mechanical foundation. In this chapter, quantum mechanical methods and applications to investigate these challenging materials will be given, along with descriptions of how these can be used to enable a quantum-informed multiscale M&S capability for energetic materials. Current capability gaps will be presented, along with suggestions for research advances needed to address these deficiencies.
Applications of Targeted Proteomics in ADME for IVIVE

Membrane transporters act as physiological “gatekeepers” that regulate the distribution of endogenous and exogenous compounds. It is therefore imperative that drug discovery/development research considers the function and expression of drug transporters, which can dictate drug concentration to pharmacological targets or may be the drug target themselves. Variation in transporter expression across species and in vitro models is recognized as a major complicating factor encountered during in vitro–in vivo extrapolations that can limit a model’s predictive power. This is particularly problematic in scenarios such as biliary secretion that are dependent upon in vitro and preclinical data due to lack of clinical bile samples. Consequently, quantification of drug transport proteins becomes a fundamental element in establishing important correlations for pharmacokinetic predictions that are of significant interest during drug discovery. In this chapter we provide an overview of methodologies relevant to protein quantification and their important limitations, followed by a review of recent studies in which mass spectrometry-based targeted quantifications of drug transporters are applied in predictions of transporter-mediated drug clearance.
New Immunotherapies in Oncology Treatment and Their Side Effect Profiles.

Background: Immunotherapies in cancer treatment have a long history going all the way back to the very beginning of the field, and recent advances are extremely promising. These therapies are becoming a larger part in many patients9 oncology treatment as the number of approaches, individual medicines, and indications increase. Furthermore, these novel therapies have different side effect profiles from those traditional chemotherapies which have, until recently, typified the oncologist9s approach to treatment together with surgery and radiation. Methods: An electronic literature search was conducted in May and June 2017 and March 2018 with the PubMed and Ebscohost databases. Articles were chosen for their relevance to the drugs in question, cancer physiology, or historic significance. Conclusions: Checkpoint inhibitors are becoming very common and possess autoimmune side effects such as pneumonitis, hypothyroidism, and colitis. These may present at any time the patient is on the medications but are more common several weeks to several months from beginning therapy. Chimeric antigen receptor T-cell therapies are powerful but have strong side effects such as cytokine release syndrome. Neoantigens are currently in the early stages of clinical trials and may become an exciting avenue for personalized cancer treatment but are not yet typical.
Abstract SY29-03: The impact of aerobic exercise on breast cancer progression

In 1924, Otto Warburg first postulated that cancer was caused by altered metabolism, specifically the reliance of cancer cells on glycolysis. Since then, this altered metabolism has been recognized as a "hallmark of cancer," with numerous studies supporting this. It is now clear that pathologies resulting in perturbed homeostasis at the level of the organism, such as obesity, diabetes, and hypercholesterolemia, are also associated with tumor progression. Since aerobic exercise is known to alter systemic homeostasis, we reasoned that it may also impact tumor progression. In this regard, emerging epidemiologic evidence indicates an inverse correlation between exercise and the onset of many forms of cancer, including breast cancer. Intriguingly, several studies have found that self-reported physical activity is associated with decreased recurrence. We have now directly tested the impact of exercise on the progression of breast cancer, using several murine models of mammary cancer, finding that exercise significantly reduces tumor growth and metastasis. Subsequent work has been focused on delineating the molecular mechanisms by which exercise hinders the progression of breast cancer. We will discuss these results and present our current understanding of how exercise influences tumor pathophysiology. Collectively, our work suggests that aerobic exercise may offer an effective complementary adjunct therapy with current standard of care. Citation Format: Erik R. Nelson. The impact of aerobic exercise on breast cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr SY29-03.
Reflection of Modulated Radio (ReMoRa): Link Analysis of Ambient Scatter Radio Using Perfect Pulses

This paper explores the range and signalling limitations of ambient scatter wireless communications. Using previously modulated and transmitted electromagnetic waves as a means of power and as the RF carrier for their own communications, Reflection of Modulated Radio (ReMoRa) systems require little to no power to establish a communication link. However, employing a carrier the ReMoRa users have no control over poses a set of signalling problems that must be addressed to ensure a functioning communication link. This paper seeks to outline these obstacles and the unique demands they place on ambient scatter systems. A novel waveform, the perfect pulse, is further characterized to better solidify their candidacy as a powerful tool for the ambient communications problem, paying specific attention to DC-nulling behaviors and synchronization benefits. Spectral Exceedance is proposed as a means to compare the depth and width of DC-nulling waveforms. A realistic RF link budget is proposed to model expected RF returns and range limitations of ReMoRa systems.
Agricultural Crop Forecasting for Large Geographical Areas

Crop forecasting is important to national and international trade and food security. Although sample surveys continue to have a role in many national crop forecasting programs, the increasing chall...
Three Perspectives on Mental Health Problems of Young Adults and their Parents at a 15-Year Follow-up of the Family Bereavement Program

Objective Effects are reported of the Family Bereavement Program (FBP) on the mental health of bereaved youth and their surviving parent 15 years following the program. Method On-hundred and 56 families (244 children ages 8-16; 54% male; 67% Non-Hispanic White) were randomly assigned to receive either the FBP (N = 90) or a literature control condition (N = 66). At the 15-year follow-up 80% of the youth and 76% of the bereaved parents were reinterviewed. Mental health problems and service use were self-reported by young adults and their parents. Key informants reported on mental health problems of young adults. Results Young adults in the FBP reported significantly less use of mental health services and of psychiatric medication than controls. Key informants reported significantly lower mental health problems for young adults who were in FBP as compared with controls and for those who were younger lower internalizing and externalizing problems for those in the FBP as compared with controls. Bereaved parents reported a significantly lower rate of alcoholism and less use of support groups than controls. Conclusions The results provided evidence that FBP led to lower mental health problems and less service use by bereaved young adults and their parents as compared with controls. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
The Cost of War: Attachment and MMO Gamers' Online and Offline Relationships

This study examined attachment styles, online behaviours, offline relationships, and sexuality of individuals engaged in a popular massive multiplayer online (MMO) game (Game of War: Fire Age). 178 players currently involved in romantic relationships completed surveys for in-game currency. Time spent gaming predicted less time with others, less relationship satisfaction, more relationship uncertainty, more sexual anxiety, and more external sexual control. However, attachment avoidance partially mediated the relationship between time spent online gaming and time spent with immediate family and friends; relationship satisfaction; self-partner, and relationship uncertainty; sexual anxiety; and external sexual control.
Universal influenza vaccine approaches using full-length or head-only hemagglutinin proteins.

There is currently an unmet need to develop an effective broadly reactive or universal vaccine against influenza viruses capable of conferring protection against both seasonal and prepandemic strains. Influenza vaccines elicit immune responses that are protective against antigenically similar viruses within a subtype. These vaccines elicit antibodies that target the surface viral glycoproteins hemagglutinin and neuraminidase. If there is an antigenic mismatch between these proteins in the influenza vaccines and cocirculating influenza isolates, there is a decrease in the vaccine effectiveness in vaccinated persons. Various novel influenza vaccine candidates are being evaluated in animal studies and clinical human trials. This article focuses on the advantages and potential shortcomings of broadly reactive or universal vaccine candidates based on the hemagglutinin globular head and the thoughts about using this antigen as the basis for future influenza vaccine strategies.
Life history and ecology of the endangered Poweshiek skipperling Oarisma poweshiek in Michigan prairie fens

Poweshiek skipperling (Oarisma poweshiek, Lepidoptera: Hesperiidae) has experienced a range-wide decline resulting in six reported extant sites. Critical knowledge gaps related to Poweshiek skipperling adult behavior, phenology, habitat structure, and potential larval host plants are limiting the ability to manage this federally endangered species. To address these information needs, we conducted extensive surveys in the last remaining stronghold of four extant prairie fens in Michigan. We used point transect surveys to collect data on plant structure, and Poweshiek skipperling behavior and detection. We estimated Poweshiek skipperling abundance and modeled the influence of local vegetation on Poweshiek skipperling presence/absence. We estimated the abundance of adult Poweshiek skipperling in Michigan prairie fens to be 231 (95% CI 160–332), further highlighting the imperiled status of this species. Presence of Poweshiek skipperling along our transects was negatively associated with obstructive vegetation and positively associated with the availability of the nectar source Dasiphora fruticosa. Our observation data indicated females nectared most frequently on D. fruticosa, whereas males nectared most often on Rudbeckia hirta. Across the field season we observed 7 oviposition events on four plant species (Muhlenbergia richardsonis, Muhlenbergia glomerata, Carex sterilis, and D. fruticosa), three of which had no previous documentation as a possible host plant. Results from this study can be used to evaluate management decisions and inform both in situ and ex situ conservation efforts. It is critical to continue monitoring remaining populations, not only to assess conservation efforts, but also to discern the patterns and processes influencing species extinction.
Abstract 530: Cardiac Fibroblast GSK-3α Contributes to Ventricular Remodeling and Dysfunction of the Failing Heart

Background: Heart failure is the leading cause of mortality, morbidity, and healthcare expenditures worldwide. Numerous studies from our lab and others have implicated Glycogen Synthase Kinase-3 (G...
A Look at Behavioral Antitrust from 2018

Behavioral antitrust has proved to have staying power, with continued attention as an area of scholarly inquiry now two decades after the foundational work in behavioral law and economics was published. This short article revisits the origin and meaning of behavioral antitrust and highlights a few areas of its application. The article shows that nothing has been written that directly challenges the applications. It does address critiques of behavioral antitrust, which are several and in some cases strong, and shows how they do not engage the proponents of behavioral antitrust directly. Instead, while proponents identify areas of application, detractors rue the lack of a general theory. The paper concludes that the progress of antitrust law and economics accommodates new information whether from behavioral economics or any other source, and as that information becomes sufficiently well understood it may lead to an adjustment of standards.
Early Estimates of the Indirect Effects of the Coronavirus Pandemic on Maternal and Child Mortality in Low- and Middle-Income Countries

Background: While the coronavirus pandemic will increase mortality due to COVID-19, the indirect effects of the pandemic will likely increase mortality from oth
Examining Relationships between Education Abroad Program Design and College Students' Global Learning

Education abroad is a high impact practice that can lead to transformational learning because it challenges students emotionally and intellectually. However, differences in program design may have differential impacts on students’ learning. The purpose of this study was to understand the relationships between desi gn features of education abroad programs specifically, program duration and the extent of students’ engagement in learning and with local communities while abroad and participants’ pre test to post test growth in global learning, measured via the nationall y validated Global Perspective Inventory survey. Using structural equation models, we found program duration and frequency of engagement in certain learning and engagement abroad to have positive effects on participants’ growth, although the relationships varied depending on the dimension of global perspective being measured. Nonetheless, our results provide further support for the need tointentionally design education abroad programs that facilitate deep learning and community interaction in order to ensure student learning.
Familial and Parental Ethnic Socialization Within Majority, Minority, and Multiracial Groups:

As ethnic diversity grows within the United States, so does the need for understanding ethnic identity (EI), which develops through ethnic socialization (ES). In a family context, this is known as ...
Durability Assessment of 15- to 20-Year-Old GFRP Bars Extracted from Bridges in the US. I: Selected Bridges, Bar Extraction, and Concrete Assessment

Abstract Glass fiber–reinforced polymer (GFRP) bars have been used in concrete structures as an alternative to steel bars due to their noncorrosive behavior. However, due to the lack of full unders...
The Experience of Women in Hospital Medicine Leadership: a Qualitative Study

Since 2017, women have made up over 50% of medical school matriculants; however, only 16% of department chairs are women—a number that has remained stagnant and demonstrates the underrepresentation of women in leadership positions in medicine. To better understand the challenges women face in leadership positions and to inform how best to advance women leaders in Hospital Medicine. Using hermeneutical phenomenological methods, we performed semi-structured qualitative interviews of ten female division heads from hospital medicine groups in the USA, transcribed verbatim, and coded for thematic saturation using Atlas.ti software. Qualitative themes and subthemes. Ten women hospitalist leaders were interviewed from September through November 2019. Participants identified four key challenges in their leadership journeys: lack of support to pursue leadership training, bullying, a sense of sacrifice in order to achieve balance, and the need for internal and external validation. Participants also suggested key interventions in order to support women leaders in the future: recommending a platform to share experiences, combat bullying, advocate for themselves, and bolster each other in sponsorship and mentorship roles. Finally, participants identified how they have unique strengths as women in leadership, and are transforming the culture of medicine with a focus on diversity and flexibility. Women in leadership positions face unique challenges, but also have a unique perspective as to how to support the next generation of leaders.
Commentary on “A Biomechanical and Microstructural Analysis of Bovine and Porcine Pericardium for Use in Bioprosthetic Heart Valves”

The use of replacement heart valves continues to grow due to the increased prevalence of valvular heart disease resulting from an aging population worldwide. For approximately the last two decades,...
Weakly-supervised Graph Meta-learning for Few-shot Node Classification.

Graphs are widely used to model the relational structure of data, and the research of graph machine learning (ML) has a wide spectrum of applications ranging from drug design in molecular graphs to friendship recommendation in social networks. Prevailing approaches for graph ML typically require abundant labeled instances in achieving satisfactory results, which is commonly infeasible in real-world scenarios since labeled data for newly emerged concepts (e.g., new categorizations of nodes) on graphs is limited. Though meta-learning has been applied to different few-shot graph learning problems, most existing efforts predominately assume that all the data from those seen classes is gold-labeled, while those methods may lose their efficacy when the seen data is weakly-labeled with severe label noise. As such, we aim to investigate a novel problem of weakly-supervised graph meta-learning for improving the model robustness in terms of knowledge transfer. To achieve this goal, we propose a new graph meta-learning framework -- Graph Hallucination Networks (Meta-GHN) in this paper. Based on a new robustness-enhanced episodic training, Meta-GHN is meta-learned to hallucinate clean node representations from weakly-labeled data and extracts highly transferable meta-knowledge, which enables the model to quickly adapt to unseen tasks with few labeled instances. Extensive experiments demonstrate the superiority of Meta-GHN over existing graph meta-learning studies on the task of weakly-supervised few-shot node classification.
Heterodimerization of H3K9 histone methyltransferases G9a and GLP activates methyl reading and writing capabilities.

Unique among metazoan repressive histone methyltransferases, G9a and GLP, which chiefly target histone 3 lysine 9 (H3K9), require dimerization for productive H3K9 mono (me1)- and dimethylation (me2) in vivo. Intriguingly, even though each enzyme can independently methylate H3K9, the predominant active form in vivo is a heterodimer of G9a and GLP. How dimerization influences the central H3K9 methyl binding ("reading") and deposition ("writing") activity of G9a and GLP and why heterodimerization is essential in vivo remains opaque. Here, we examine the H3K9me "reading" and "writing" activities of defined, recombinantly produced homo- and heterodimers of G9a and GLP. We find that both reading and writing are significantly enhanced in the heterodimer. Compared with the homodimers, the heterodimer has higher recognition of H3K9me2, and a striking ∼10-fold increased turnover rate for nucleosomal substrates under multiple turnover conditions, which is not evident on histone tail peptide substrates. Cross-linking Mass Spectrometry suggests that differences between the homodimers and the unique activity of the heterodimer may be encoded in altered ground state conformations, as each dimer displays different domain contacts. Our results indicate that heterodimerization may be required to relieve autoinhibition of H3K9me reading and chromatin methylation evident in G9a and GLP homodimers. Relieving this inhibition may be particularly important in early differentiation when large tracts of H3K9me2 are typically deposited by G9a-GLP, which may require a more active form of the enzyme.
Modeling the impact of vaccination strategies for nursing homes in the context of increased SARS-CoV-2 community transmission and variants

Nursing homes (NH) were among the first settings to receive COVID-19 vaccines in the United States, but staff vaccination coverage remains low at an average of 64%. Using an agent-based model, we examined the impact of community prevalence, the Delta variant, staff vaccination coverage, and boosters for residents on outbreak dynamics in nursing homes. We found that increased staff primary series coverage and high booster vaccine effectiveness (VE) in residents leads to fewer infections and that the cumulative incidence is highly dependent on community transmission. Despite high VE, high community transmission resulted in continued symptomatic infections in NHs.
Abstract 77: Posterior Circulation Stroke in Children Due to Cervical Spine Abnormalities

Background: Vertebral artery dissection due to dynamic compression by abnormal C1-C2 anatomy is under-recognized in childhood stroke. Our aim was to describe underlying pathologic variants of C1-C2 soft tissue or bone in children with vertebral artery dissection and posterior circulation strokes. Methods: A series of five children diagnosed with vertebral artery dissection from compression by C1-C2 soft tissue or bone were identified at a single pediatric stroke center. Diagnostic evaluation, anatomic cause of dissection, and treatment were abstracted from medical records. Results: Five children (all boys, ages 6 - 14) were identified with a diagnosis of posterior circulation embolic strokes due to focal vertebral artery dissection and presumed compression against adjacent C1-C2 abnormalities. Four had recurrent events, including basilar artery thrombosis, before the cervical abnormality was identified. Vertebral artery dissections were caused by bony (congenital arcuate foramen, post-traumatic os odontoideum) and soft tissue pathology (ruptured atlantoaxial bursa, anomalous C1-C2 connective tissue bands) (Table). Vertebral artery compression at dissection sites during head rotation was confirmed by angiography with head in neutral and rotated in children with soft tissue anomalies. No other etiology for stroke or dissection was found in any of the cases. For secondary stroke prevention, four children underwent direct surgical decompression of the vertebral artery or spinal fusion; one opted for activity restriction and aspirin. None had further recurrences after treatment with a median follow-up of 9 months (range 1 to 61). Conclusions: In children with recurrent vertebral artery dissection and strokes, C1-C2 bone imaging and dynamic angiogram with neck rotation can identify cervical pathology that may otherwise be missed. Cervical stabilization or resection of the compressive pathology should be considered to prevent stroke recurrence.
Transport and Fate of Chemicals in the Environment, Introduction

Estimating the fate and transport of chemicals released into the environment is an interesting and challenging task. The environment can rarely be approximated as well mixed, and the chemicals in the environment often are not close to equilibrium. Thus, chemical fate and transport in the environment requires a background in the physics of fluid flow and transport, chemical thermodynamics, chemical kinetics, and the biology that interacts with all of these processes. The goal is to follow chemicals as they move, diffuse, and disperse through the environment. These chemicals will inevitably react to form other chemicals, in a manner that approaches, but rarely achieves, a local equilibrium. Many times, these reactions are biologically mediated, with a rate of reaction that more closely relates to an organism being hungry, or not hungry, than to first-order kinetics.
Oxidative precipitation of groundwater-derived ferrous iron in the subterranean estuary of a coastal bay

[1] Sediment cores from the intertidal zone of Waquoit Bay (Cape Cod, Massachusetts) yielded iron oxide-coated sands in the subterranean estuary, which underlies the head of the bay. The oxides were dark red, yellow and orange colors and are formed by the oxidation of ferrous iron-rich groundwater near the groundwater-seawater interface. Within these iron oxide-rich sediments, the concentration of the combined amorphous and crystalline forms of iron oxides ranged between 2500 and 4100 ppm of Fe. These concentrations were 4–6 times greater than the surface sands, and 10–15 times more Fe rich than sands collected from an off-site location. The precipitation of iron oxides in subterranean estuaries could act as a geochemical barrier by retaining and accumulating certain dissolved chemical species carried to the coast by groundwater. Indeed, phosphorus concentrations in the iron oxide-rich sands of Waquoit Bay were 5–7 times greater than the overlying surface sands.
NP-Click: A Programming Model for the Intel IXP1200

Publisher Summary A programming model inevitably balances a programmer's two competing needs: desire for ease of programming and the requirement for efficient implementation. This chapter describes NP-Click, a programming model for a common network processor, the Intel IXP 1200. The approach is illustrated by using NP-Click to implement an IPv4 packet forwarder. The IXP 1200 family is one of Intel's recent network processor product lines based on their Internet Exchange Architecture. Click is a domain-specific language designed for describing networking applications. It is based on a set of simple principles tailored for the networking community. NP-Click combines an efficient abstraction of the target architecture with features of a domain-specific language for networking. The model is designed to ease three major difficulties of programming network processors: taking advantage of hardware parallelism, arbitration of shared resources, and efficient data layout. The result is a natural abstraction that enables programmers to quickly write efficient code.
Hydrologic History, Problems, and Perspectives

Since humans first settled along the banks of lakes and rivers, there has been a keen interest in the proper management of fresh water resources both as a necessity for life as well as to avoid potential health hazards. Along the Indus in Pakistan, the Tigris and Euphrates in Mesopotamia, the Hwang Ho in China, and the Nile in Egypt, the first “hydraulic engineers” created canals, levees, dams, subsurface water conduits, and wells as early as 5000–6000 years ago. Hydrologic information became vital to these early civilizations. The flow rates and yields of rivers were monitored by the Egyptians as early as 3800 years ago, and rainfall measuring instruments were first used approximately 2400 years ago by Kautilya of India. The idea that a global hydrologic cycle actually exists dates back at least 3000 years when early Greek philosophers such as Thales, Anaxagoras, Herodotus, Hippocrates, Plato, and Aristotle conceptualized the basic ideas governing the process. Many initial ideas established by the Greeks about the hydrologic cycle were quite reasonable. However, many of the initial mechanisms concerning the routes by which water returned from the sea and entered rivers were devoid of as much logic. Despite apparent gaps in hydrologic mechanisms, the Romans developed aqueduct systems reflecting an extensive practical understanding of hydrology and hydraulics and did so using the basic hydrologic ideas established and passed along by the Greeks. Keywords: climate; education; engineering; history; hydrologic sciences; modeling; perspectives; physical processes; pollution; population; problems; research; reserves; resources; water management
Stack and area tritium monitoring systems for the Tokamak Fusion Test Reactor (TFTR)

The TFTR tritium stack and area monitoring systems have been developed to provide the required level of reliability in a cost-effective manner consistent with the mission of the tritium handling system on TFTR. Personnel protection, environmental responsibility, and tritium-containing-system integrity have been the considerations in system design. A variety of monitors has been used. Real-time area and stack monitors are tied to HVAC control systems, and passive samplers provide a continuous effluent monitoring without AC power. It is concluded that the challenge of TFTR's radiological and electrical environment has been met. >
Diffusion-Limited Contamination and Decontamination in a Layered Aquitard: Forensic and Predictive Analysis of Field Data

Subsurface zones of low hydraulic conductivity serve as sinks and sources of chemical contamination for adjacent regions of comparatively high groundwater flow, and may often control the overall rate of remediation at sites contaminated by hazardous substances. At Dover Air Force Base, DE, we have extensively characterized the concentrations and transport of chlorinated organic contaminants in a silty aquitard that underlies an unconfined aquifer, as part of a field-scale investigation involving the installation of sheet-pile enclosures to hydraulically isolate a portion of a long-extant contamination plume. Vertical contaminant concentration profiles within the test cells were obtained by means of subsurface coring, high-resolution sub-sampling and a rigorous hot-methanol extraction of total (sorbed plus aqueous) contaminants. Through independent characterization of the sorption properties and porosity in the various strata of porous media, we have explored and validated a hypothesis that the chlorinated organic chemicals have behaved conservatively and that their transport within the aquitard was dominated by a process of sorption-retarded vertical diffusion. A new analytical solution to a multi-layer diffusion model has been developed and was used both to make inferences about the historical conditions of contamination in the overlying aquifer and to make predictions regarding future rates of release. Our predictions of on-going diffusion, including back transport to the aquifer, were tested by re-coring at the site following a 15-month period during which no-flow conditions were maintained within the test cells. Overall, the project illustrates how the aquitard will be a long-term limiting factor to contaminant remediation at this site, and that rates of release will be affected both by the geologic stratification within the aquitard and by the initially complex initial conditions within this zone. These characteristics of the problem could not have been understood without the given combination of high-resolution sampling, extensive laboratory characterization, and mathematical modeling analysis.
Competition for Access and Full Revelation of Evidence

A decision maker must divide a prize between multiple agents. The prize may be divisible (e.g., a budget, pork-barrel spending) in which case he prefers to award larger shares of the prize to relatively more-qualified agents, or it may be non-divisible (e.g., jobs, college admissions) in which case he prefers to award the limited number of prizes to the most-qualified agents. He is, however, ex ante uncertain about agent quali cations. Agents may directly reveal verifiable evidence about their qualifications to the decision maker only if the decision maker grants them \access" (e.g., he takes time to review their applications, hold interviews, or conduct an investigation). The time-constrained decision maker must decide which agents receive access, as he cannot grant access to everyone. One way to award access is through a competition, where agents submit payments (e.g., time, money) and higher payments correspond to a greater likelihood of receiving access. The analysis shows that there always exists competition for access mechanisms in which the decision maker becomes fully informed about the qualifications of all agents (even though only some agents reveal their qualifications through access). That is, the decision maker can award access in such a way that he always becomes fully informed and chooses his preferred prize allocation. The paper derives such full-revelation mechanisms, and determines when awarding access through a traditional all-pay auction is sufficient for full revelation.
Pulsar-irradiated stars in dense globular clusters

We discuss the properties of stars irradiated by millisecond pulsars in 'hard' binaries of dense globular clusters. Irradiation by a relativistic pulsar wind as in the case of the eclipsing millisecond pulsar PSR 1957+20 alter both the magnitude and color of the companion star. Some of the blue stragglers (BSs) recently discovered in dense globular clusters can be irradiated stars in binaries containing powerful millisecond pulsars. The discovery of pulsar-driven orbital modulations of BS brightness and color with periods of a few hours together with evidence for radio and/or gamma-ray emission from BS binaries would valuably contribute to the understanding of the evolution of collapsed stars in globular clusters. Pulsar-driven optical modulation of cluster stars might be the only observable effect of a new class of binary pulsars, i.e., hidden millisecond pulsars enshrouded in the evaporated material lifted off from the irradiated companion star.
Artificial atoms and molecules for spintronic applications

Single spin manipulation in single and double quantum dots provides the necessary ingredients for a plausible scenario toward the realization of a scalable quantum computer with GaAs semiconductor technology.
Robust and efficient robotic mapping

Mobile robots are dependent upon a model of the environment for many of their basic functions. Locally accurate maps are critical to collision avoidance, while large-scale maps (accurate both metrically and topologically) are necessary for efficient route planning. Solutions to these problems have immediate and important applications to autonomous vehicles, precision surveying, and domestic robots. Building accurate maps can be cast as an optimization problem: find the map that is most probable given the set of observations of the environment. However, the problem rapidly becomes difficult when dealing with large maps or large numbers of observations. Sensor noise and non-linearities make the problem even more difficult—especially when using inexpensive (and therefore preferable) sensors. This thesis describes an optimization algorithm that can rapidly estimate the maximum likelihood map given a set of observations. The algorithm, which iteratively reduces map error by considering a single observation at a time, scales well to large environments with many observations. The approach is particularly robust to noise and non-linearities, quickly escaping local minima that trap current methods. Both batch and online versions of the algorithm are described. In order to build a map, however, a robot must first be able to recognize places that it has previously seen. Limitations in sensor processing algorithms, coupled with environmental ambiguity, make this difficult. Incorrect place recognitions can rapidly lead to divergence of the map. This thesis describes a place recognition algorithm that can robustly handle ambiguous data. We evaluate these algorithms on a number of challenging datasets and provide quantitative comparisons to other state-of-the-art methods, illustrating the advantages of our methods. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
Considerations of adoption.

A childbirth educator asks for advice relative to a married couple in her class who plans to give up their baby for adoption.
Determination of bromine in regulated foods with a field-portable X-ray fluorescence analyzer.

A field-portable X-ray fluorescence analyzer, factory-calibrated for soil analysis, was used to measure bromine (Br) mass fractions in reference materials, flour, bakery products, malted barley, selected U.S. Food and Drug Administration Total Diet Study foods, and other food products. By using a calibration based on instrumental neutron activation analysis results for Br in reference materials, accurate quantitative results, confirmed by z-scores, could be obtained for mass fractions of about 2–55 mg/kg. These results confirmed accuracy of results (with larger uncertainties) obtained by applying a simple correction factor to the analyzer’s output value. Results showed that very short analysis times (2 min) would be needed to screen foods for Br content at regulatory levels for brominated and enriched brominated flour (24 mg/kg Br) and whole wheat flour and bakery products (36 mg/kg Br). Feasibility for determination of Br in malted barley at the regulatory level (75 mg/kg Br) was demonstrated, but quantitative results at that level could not be assured because no reference material with a suitable mass fraction was available. Br mass fractions for all foods tested were well below regulatory levels.
The invisible and visible stigmatization of Parkinson's disease.

Purpose To discuss the visible and invisible stigma shared by seven men and seven women with Parkinson's disease (PD), a chronic, progressive, neurodegenerative disorder characterized by overt physical and covert psychological manifestations. Data sources An ethnographic approach using interview data, participant observations, and fieldwork was used. Field data were generated from a 2-year exposure to two PD support groups in east Texas. The question “what does it mean to you to have Parkinson's disease"? illuminated the experience of everyday life and the existential meaning of what it means to live with this disease. Conclusions The invisible stigma was that of a changing self, a self with PD, a form of disability, which attested to the stigma and mounting isolation. Feelings of isolation were exacerbated by both the stigmatization associated with being different, coupled with the realization that life would never be the same. Facial masking was identified as one of the visible features that were commonly reported by all participants. Implications for practice Healthcare professionals can be more attuned to the visible and invisible manifestations of PD that are associated with stigma through the incorporation of a holistic assessment to identify perceived stigma in persons living with the disease.
A Strong and Mechanizable Grand Logic

The purpose of this paper is to describe a "grand logic", that is, a system of higher order logic capable of use as a general purpose foundation for mathematics. This logic has developed as the logic of a theorem proving system which has had a number of names in its career (EFTTP, Mark2, and currently Watson), and the suitability of this logic for computer-assisted formal proof is an aspect which will be considered, though not thoroughly. A distinguishing feature of this system is its relationship to Quine's set theory NF and related untyped λ-calculi studied by the author.