cssi/SciSciGPT-SciSciNet huggingface dataset:
The Transformation of U.S. Immigration Federalism: A Critical Reading of Arizona v. United States

In the United States, the legal challenges to a recent spate of state and local laws aimed at regulating migration have revolved primarily around questions of immigration federalism. The primary argument of litigants challenging state and local ordinances such as Arizona’s S.B. 1070 or Hazelton, Pennsylvania’s ordinance concerning the employment and housing of unauthorized migrants has been a federal preemption argument. Simply put, the argument is that state and local immigration regulations are preempted by the comprehensive federal scheme regulating immigration. Defenders of the laws have taken the position—again relying on the jurisprudence that has evolved in the context of immigration federalism—that these laws and ordinances are not preempted because they exist in the interstices of and do not conflict with federal immigration regulation. Additional constitutional questions such as equal protection arguments or Fourth Amendment arguments have been raised as well, but those questions are being litigated in the shadows of the preemption arguments. Thus, the body of law concerning immigration federalism has been the primary tool used by courts thus far to resolve increasingly common questions about sub-federal immigration regulation.
Early Hypertension and Diabetes After Living Kidney Donation: A National Cohort Study.

Background Living kidney donors have an increased risk of end-stage renal disease, with hypertension and diabetes as the predominant causes. In this study, we sought to better understand the timeline when these diseases occur, focusing on the early postdonation period. Methods We studied 41 260 living kidney donors in the United States between 2008 and 2014 from the Scientific Registry of Transplant Recipients and modeled incidence rates and risk factors for hypertension and diabetes. Results At 6 months, 1 year, and 2 years postdonation, there were 74, 162, and 310 cases, respectively, of hypertension per 10 000 donors. Donors who were older (per 10 y, adjusted incidence rate ratio [aIRR], 1.40; 95% confidence interval [CI], 1.29-1.51), male (aIRR, 1.31; 95% CI, 1.14-1.50), had higher body mass index (per 5 units, aIRR, 1.29; 95% CI, 1.17-1.43), and were related to their recipient (first-degree relative: aIRR, 1.28; 95% CI, 1.08-1.52; spouse: aIRR, 1.34; 95% CI, 1.08-1.66) were more likely to develop hypertension, whereas donors who were Hispanic/Latino were less likely (aIRR, 0.71; 95% CI, 0.55-0.93). At 6 months, 1 year, and 2 years, there were 2, 6, and 15 cases of diabetes per 10 000 donors. Donors who were older (per 10 y: aIRR, 1.42; 95% CI, 1.11-1.82), had higher body mass index (per 5 units: aIRR, 1.52; 95% CI, 1.04-2.21), and were Hispanic/Latino (aIRR, 2.45; 95% CI, 1.14-5.26) were more likely to develop diabetes. Conclusions In this national study, new-onset diabetes was rare, but 3% of donors developed hypertension within 2 years of nephrectomy. These findings reaffirm that disease pathways for kidney failure differ by donor phenotype and estimate the population most at-risk for later kidney failure.
Sarcomatoid carcinoma in cytology: Report of a rare entity presenting in pleural and pericardial fluid preparations.

Sarcomatoid carcinoma is rarely found in pleural or pericardial fluid, with very few cases published to date. Here, we describe a 59-year-old female who presented with cough persisting for 5 months. Chest CT scan revealed a 6.0 cm cavitary mass in the left lung base with bulky mediastinal and hilar lymphadenopathy. An additional 1.2 cm right adrenal mass was seen and was suspicious for metastatic disease. The patient developed dyspnea, tachycardia, pleuritic chest pain and generalized weakness and was admitted to the hospital. She was found to have pleural and pericardial effusions, which were drained and sent to cytology. The fluid revealed enlarged highly pleomorphic malignant cells, some displaying multinucleation with irregular nuclear borders, coarse chromatin and prominent nucleoli. Tumor cells were positive for CK7 and Vimentin and negative for MOC-31, Ber-EP4, B72.3, Sox10, Melan-A, TTF-1, Napsin-A and CK20. A concurrent surgical biopsy of the tumor mass displayed immunopositivity for AE1/AE3 and CAM5.2. The tumor was negative for p40, TTF-1, calretinin, D2-40 and STAT6. A diagnosis of sarcomatoid carcinoma with giant cells and spindle cells was rendered. Sarcomatoid carcinomas of the lung are very uncommon consisting of 1% of non-small-cell lung carcinomas and are even more unusual in cytology specimens. Despite its rarity, it is important to keep this entity in mind in the differential diagnosis of a fluid specimen with bizarre nuclear atypia and the above staining pattern.
The Thermal Neutron Capture Cross Sections and Resonance Integrals of 144Sm and 145Sm

Two-group integral neutron capture cross sections have been measured for 144Sm and 145Sm. Mass spectrographic assays were carried out on highly enriched samples of 144Sm that were irradiated in a h...
Single cell analysis of the effects of developmental lead (Pb) exposure on the hippocampus

Background: Lead (Pb) exposure is ubiquitous and has permanent developmental effects on childhood intelligence and behavior and adulthood risk of dementia. The hippocampus is a key brain region involved in learning and memory, and its cellular composition is highly heterogeneous. Pb acts on the hippocampus by altering gene expression, but the cell type-specific responses are unknown. Objective: Examine the effects of perinatal Pb treatment on adult hippocampus gene expression, at the level of individual cells, in mice. Methods: In mice perinatally exposed to control water (n=4) or a human physiologically-relevant level (32 ppm in maternal drinking water) of Pb (n=4), two weeks prior to mating through weaning, we tested for gene expression and cellular differences in the hippocampus at 5-months of age. Analysis was performed using single cell RNA-sequencing of 5,258 cells from the hippocampus by 10x Genomics Chromium to 1) test for gene expression differences averaged across all cells by treatment; 2) compare cell cluster composition by treatment; and 3) test for gene expression and pathway differences within cell clusters by treatment. Results: Gene expression patterns revealed 12 cell clusters in the hippocampus, mapping to major expected cell types (e.g. microglia, astrocytes, neurons, oligodendrocytes). Perinatal Pb treatment was associated with 12.4% more oligodendrocytes (P=4.4x10-21) in adult mice. Across all cells, differential gene expression analysis by Pb treatment revealed cluster marker genes. Within cell clusters, differential gene expression with Pb treatment (q<0.05) was observed in endothelial, microglial, pericyte, and astrocyte cells. Pathways up-regulated with Pb treatment were protein folding in microglia (P=3.4x10-9) and stress response in oligodendrocytes (P=3.2x10-5). Conclusion: Bulk tissue analysis may be confounded by changes in cell type composition and may obscure effects within vulnerable cell types. This study serves as a biological reference for future single cell studies of toxicant or neuronal complications, to ultimately characterize the molecular basis by which Pb influences cognition and behavior.
The impact of stroma admixture on molecular subtypes and prognostic gene signatures in serous ovarian cancer

Background: Recent efforts to improve outcomes for high-grade serous ovarian cancer, a leading cause of cancer death in women, have focused on identifying molecular subtypes and prognostic gene signatures, but existing subtypes have poor cross-study robustness. We tested the contribution of cell admixture in published ovarian cancer molecular subtypes and prognostic gene signatures. Methods: Gene signatures of tumor and stroma were developed using paired microdissected tissue from two independent studies. Stromal genes were investigated in two molecular subtype classifications and 61 published gene signatures. Prognostic performance of gene signatures of stromal admixture was evaluated in 2,527 ovarian tumors (16 studies). Computational simulations of increasing stromal cell proportion were performed by mixing gene-expression profiles of paired microdissected ovarian tumor and stroma. Results: Recently described ovarian cancer molecular subtypes are strongly associated with the cell admixture. Tumors were classified as different molecular subtypes in simulations where the percentage of stromal cells increased. Stromal gene expression in bulk tumors was associated with overall survival (hazard ratio, 1.17; 95% confidence interval, 1.11–1.23), and in one data set, increased stroma was associated with anatomic sampling location. Five published prognostic gene signatures were no longer prognostic in a multivariate model that adjusted for stromal content. Conclusions: Cell admixture affects the interpretation and reproduction of ovarian cancer molecular subtypes and gene signatures derived from bulk tissue. Elucidating the role of stroma in the tumor microenvironment and in prognosis is important. Impact: Single-cell analyses may be required to refine the molecular subtypes of high-grade serous ovarian cancer.
Clone granular soils with mixed particle morphological characteristics by integrating spherical harmonics with Gaussian mixture model, expectation–maximization, and Dirichlet process

Computers have been taught to clone granular soil particles for discrete element method simulations to alleviate difficulties of using three-dimensional imaging techniques for scanning a large number of particles. In this process, computers analyze a few scanned particles to extract morphological characteristics of the target soil, which are used to clone as many particles as necessary. However, many natural granular soils contain a wide range of particle shapes mixing more than one type of morphological characteristics, causing difficulties in cloning. This research aims to address this challenge by integrating spherical harmonics with Gaussian mixture model, expectation–maximization, and Dirichlet process. Spherical harmonics coefficients are used to characterize morphological information of the granular soil. Gaussian mixture model is used to fit a function to the mixed morphological characteristics. The expectation–maximization and Dirichlet process are used to estimate the fitting parameters in Gaussian mixture model. Then, Gaussian mixture model is used to generate new spherical harmonics coefficients and then generate new particles. The effectiveness and accuracy of the proposed methodology are verified using a Griffin sand. Although this approach is developed for granular soils, the proposed technique can also be used to clone other particulate materials.
Reflection on ERISA Claims Administration and the Exhaustion Requirement

This essay, prepared in connection with the Drexel Law Review Symposium, ERISA at 40: What Were They Thinking?, examines ERISA’s regime for administering benefit claims and, in particular, the requirement that participants exhaust their plan’s review procedures before filing suit to recover benefits. Like other key elements of ERISA’s claims regime, the exhaustion requirement is a judicial creation that is not articulated in ERISA’s text. Interestingly, former congressional staffers who attended the Symposium said they assumed participants would be required to exhaust plan review procedures but failed to include such a requirement in the legislation. After reviewing the development of the exhaustion requirement and the debate over its merit as a matter of policy, the essay concludes with an examination of evidence from the text and legislative history of ERISA’s remedial provisions. This evidence suggests that ERISA’s drafters rejected the idea that participants should have to satisfy a prerequisite, such as the exhaustion requirement, before filing suit to enforce benefit rights.
Incoming medical students' knowledge of and attitudes toward people with substance use disorders: Implications for curricular training.

Medical students may be in an ideal position to identify patients with substance use disorders (SUDs) and provide them with information about harm reduction and treatment options. Specific educatio...
Perioperative Antibiotic Prophylaxis: Single and 24-Hour Antibiotic Dosages are Equally Effective at Preventing Periprosthetic Joint Infection in Total Joint Arthroplasty

Abstract Background Perioperative antibiotic prophylaxis is used to prevent surgical site infection and periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). Secondary to a national shortage of cefazolin, patients at our institution began receiving a single preoperative prophylactic antibiotic dose for primary TJA and no 24-hour postoperative antibiotic prophylaxis. The purpose of the study was to compare the efficacy of single-dose antibiotic use versus 24-hour dosing of prophylactic antibiotics in the prevention of acute PJI and short-term complications after primary TJA. Methods A retrospective review of 3317 patients undergoing primary TJA performed from January 2015 to December 2019 identified 554 patients who received a single dose of preoperative antibiotic prophylaxis during the antibiotic shortage and 2763 patients who received post-TJA 24-hour antibiotic prophylaxis before the shortage. Patient records were evaluated for acute PJI, superficial infection, 90-day reoperation, and 90-day complications. Results There were no significant differences in patient characteristics between single-dose and 24-hour antibiotic groups. Similarly, there were no significant differences in rates of acute PJI (0.7% vs 0.2%; P = .301), superficial infection (2.4% vs 1.4%; P = .221), 90-day reoperation (2.1% vs 1.1%; P = .155), and 90-day complications (9.9% vs 7.9%; P = .169) between single and 24-hour antibiotic dose. Post hoc power analysis demonstrated adequate sample size, beta = 93%. Conclusion Single-dose prophylactic antibiotics did not lead to an increased risk of acute PJI or short-term complications after TJA. Our study suggests that administration of a single antibiotic dose may be safely considered in patients undergoing routine primary TJA.
Physical Activity and Sleep Measures Using a Fitness Tracking Device during Hematopoietic Cell Transplantation: A Pilot Study.

ABSTRACT Patients undergoing hematopoietic cell transplantation (HCT) experience decline in their physical activity during their transplant admission. There is limited experience with prospective monitoring of transplant recipients. We therefore measured physical activity and sleep patterns of subjects undergoing autologous and allogeneic HCT. Eighty-three patients were consented for this study. Sixty-three patients competed the study and had their physical activity prospectively assessed using the fitness-tracking device Fitbit HR. Outcomes included adherence, physical activity, readmission, hematopoietic engraftment, and 100-day survival. Sixty percent of patients (n = 37) underwent autologous HCT, and 40% (n = 26) underwent allogenic HCT. Both groups had a comparable number of steps at admission to the hospital. The number of daily steps during the study period was lower in the allogeneic group (2159 versus 3008, P = .07), as was the minimum number of steps recorded over the transplant admission (allogeneic HCT = 395 versus autologous HCT = 848, P = .01). Patients undergoing allogeneic HCT were less active on the day before discharge (1956 steps versus 3183 steps, P = .08). In multivariate analysis, physical activity was not associated with HCT-related outcomes. Patients undergoing HCT experience significant decline in their physical activity during their transplant admission that does not recover by the time of discharge. This effect can be objectively measured using fitness tracking devices.
Examination of the ‘5-2-1-0’ Recommendations in Racially Diverse Young Children Exposed to Tobacco Smoke:

Purpose:The ‘5-2-1-0’ guidelines recommend that children: eat ≥5 servings of fruits/vegetables (‘5’), have ≤2 hours of screen-time (‘2’), have ≥1 hour of activity (‘1’), and drink 0 sugar-sweetened...
A T1-based correction method for proton resonance frequency shift thermometry in breast tissue.

PURPOSE Develop and evaluate the effectiveness of a T1-based correction method for errors in proton resonant frequency shift thermometry due to non-local field effects caused by heating in fatty breast tissues. METHODS Computational models of human breast tissue were created by segmenting MRI data from a healthy human volunteer. MR-guided focused ultrasound (MRgFUS) heating and MR thermometry measurements were simulated in several locations in the heterogeneous segmented breast models. A T1-based correction method for PRF thermometry errors was applied and the maximum positive and negative errors and the root mean squared error (RMSE) in a region around each heating location was evaluated with and without correction. The method uses T1 measurements to estimate the temperature change in fatty tissues and correct for their influence. Experimental data from a heating study in cadaver breast tissue were analyzed, and the expected PRFS error computed. RESULTS The simulated MR thermometry had maximum single voxel errors ranging between 10% and 18% when no correction was applied. Applying the correction led to a considerable improvement, lowering the maximum error range to 2%-5%. The 5th to 95th percentile interval of the temperature error distribution was also lowered with correction, from approximately 3.5 to 1°C. This correction worked even when T1 times were uniformly raised or lowered by 5%-10%. The experimental data showed predicted errors of 15%. CONCLUSIONS This simulation study demonstrates that the T1-based correction method reduces MR thermometry errors due to non-local effects from heating in fatty tissues, potentially improving the accuracy of thermometry measurements during MRgFUS treatments. The presented correction method is reliant on having a patient-specific 3D model of the breast, and may be limited by the accuracy of the fat temperatures which in turn may be limited by noise or bias present in the T1 measurements.
Mortality, sepsis, and organ failure in hospitalized patients with cirrhosis vary by type of infection.

Background and aim Infection is associated with substantial morbidity and mortality in cirrhosis, but presumably, not all infections carry the same risk of mortality. We compared outcomes of different sites of infection in a nationally representative sample of inpatients with cirrhosis. Methods We queried the Nationwide Readmissions Database for patients with cirrhosis from 2011 to 2014. Cirrhosis and infection diagnoses were identified by previously used algorithms of ICD-9 codes. The following infections were compared: urinary tract infection (UTI), pneumonia, cellulitis, spontaneous bacterial peritonitis (SBP), and Clostridium difficile infection (CDI). The primary outcome was inpatient mortality. Secondary outcomes included sepsis, any organ failure, multiple organ failures, and 30-day readmission. Outcomes were analyzed using logistic regression and included a priori covariates. Results A total of 1 798 830 weighted index admissions were identified. Infection was present in 29.2% overall-including UTI (13.7%), pneumonia (8.9%), cellulitis (5.2%), CDI (2.8%), and SBP (2.0%). Mortality was significantly higher in pneumonia (19.6%), SBP (18.6%), and CDI (17.4%) compared with cellulitis (7.6%) and UTI (11.8%). Sepsis, any, and multiple organ failures were most commonly seen in pneumonia, SBP, and CDI. Multivariable analysis demonstrated that pneumonia had the highest associated mortality (odds ratio [OR] 2.73, confidence interval [CI] 2.68-2.80) and multiple organ failures (OR 3.59, CI 3.50-3.68). Significantly increased 30-day readmission was seen only with SBP (24.9%). Conclusions Outcomes of inpatients with cirrhosis vary significantly depending on the type of infection. The severity and epidemiology of infection in cirrhosis appears to be shifting with pneumonia, not SBP, having the highest prevalence of multiple organ failures and inpatient mortality.
Quantitation of Benzodiazepines in Blood and Urine Using Gas Chromatography-Mass Spectrometry (GC-MS)

The benzodiazepine assay utilizes gas chromatography-mass spectrometry (GC-MS) for the analysis of diazepam, nordiazepam, oxazepam, temazepam, lorazepam, alpha-hydroxyalprazolam, and alpha-hydroxytriazolam in blood and urine. A separate assay is employed for the analysis of alprazolam. Prior to solid phase extraction, urine specimens are subjected to enzyme hydrolysis. The specimens are fortified with deuterated internal standard and a five-point calibration curve is constructed. Specimens are extracted by mixed-mode solid phase extraction. The benzodiazepine extracts are derivatized with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSFTA) producing tert-butyldimethyl silyl derivatives; the alprazolam extracts are reconstituted in methanol without derivatization. The final extracts are then analyzed using selected ion monitoring GC-MS.
Son Preference in India: Implications for Gender Development

Abstract:Using data from the census of India and the National Family Health Survey (NFHS), this paper analyzes trends in child sex ratios (0-6 years of age) and the increase in son preference in India. Latest census data (2011) show that the child sex ratios (females per 1,000 males) have decreased compared to data from the last five decades. Increasing son preference and neglect of daughters is occurring in many states in India, despite the advances made in education, literacy, healthcare, and income attainment. A skewed sex ratio and shortage of girls is detrimental to the health and welfare of women, as well as to the human development of India. Policymakers need to formulate appropriate policies, coupled with strict enforcement laws, in order to contain this grave trend in son preference and the infanticide, neglect, and devaluation of women in India.
Unexpected death due to acute airway obstruction in daycare centers

Sudden collapse due to acute upper aerodigestive tract obstruction in infants and young children is most often caused by ingested food or toy parts.1,2 Although attention has been previously drawn to the different pattern of food asphyxiation in children compared with adults,2 the following two cases taken from the autopsy files of the Adelaide Children9s Hospital over a 20-year period demonstrate particular risk factors associated with young children eating in daycare centers. CASE REPORTS Case 1 A 19-month-old healthy boy was eating a sausage happily in a daycare center when last observed by a caretaker who was then absent for several minutes.
Understanding perceived organizational identity during crisis and change

Purpose – The purpose of this paper is to provide a framework for predicting the role and effects of perceived organizational identity (POI) on organizational members' perceptions and behaviors during crisis and change situations, and the scope of the resulting POI changes that may occur.Design/methodology/approach – The paper brings together research on crisis, change, threat/opportunity, and POI, along with case study data to create a threat/opportunity framework for making these predictions.Findings – Based on whether threat or opportunity is perceived during crisis and change situations, different aspects of individuals' POIs will become salient. In threat situations, individuals will focus on perceptions of “who we are.” In opportunity situations, individuals will also focus on “who we could be.” The focus of attention and the threat/opportunity context will influence organizational identification, learning, and openness to change; and whether incremental or transformational POI change occurs. The pe...
Automata, Probability, and Recursion

We discuss work on the modeling and analysis of systems with probabilistic and recursive features. Recursive Markov chains extend ordinary finite state Markov chains with the ability to invoke other Markov chains in a potentially recursive manner. The equivalent model of Probabilistic Pushdown Automata extends ordinary pushdown automata with probabilistic actions. Both of these are natural abstract models for probabilistic programs with procedures, and related systems. They generalize other classical well-studied stochastic models, e.g. Stochastic Context-free Grammars and (Multi-type) Branching Processes, that arise in a variety of areas. More generally, Recursive Markov Decision Processes and Recursive Stochastic Games can be used to model recursive systems that have both probabilistic and nonprobabilistic, controllable actions. In recent years there has been substantial work on the algorithmic analysis of these models, regarding basic questions of termination, reachability, and analysis of the properties of their executions. In this talk we will present some of the basic theory, algorithmic methods, results, and challenges.
Be careful what you wish for: the stock market reactions to bailing out large financial institutions

Purpose – The purpose of this paper is to examine the implicit subsidies received, in the form of stock market returns, from the perception that large banking organizations are too big to fail, and implications for financial regulation.Design/methodology/approach – The empirical analysis focuses on the responses of stock prices of various size groups of banking organizations to announcement of government capital injections to banks (troubled assets relief program) during the 2008 financial crisis, and summarizes responses of regulatory authorities to the crisis.Findings – The paper finds positive and statistically significant stock return reactions both for a portfolio of the large banking organizations that are part of the initial capital injection plan and a portfolio of the large banking organizations that are not part of the initial capital injection plan, implying a too‐big‐to‐fail (TBTF) effect, especially for the latter group of institutions.Research limitations/implications – The paper focuses on ...
Strand displacement synthesis capability of Moloney murine leukemia virus reverse transcriptase.

The accepted model of retroviral reverse transcription includes a circular DNA intermediate which requires strand displacement synthesis for linearization and creation of an integration-competent, long terminal repeat-flanked DNA product. We have used an in vitro model of this last step of reverse transcription to examine the role of the viral enzyme, reverse transcriptase (RT), in displacement synthesis. We show that Moloney murine leukemia virus RT possesses an activity which allows for displacement synthesis through a minimum of 1,334 bp of duplex DNA--an extent much greater than that required during in vivo reverse transcription and over 25-fold greater than has been previously demonstrated for a viral RT. RT does not function as a helicase in the classical sense but appears to closely couple duplex DNA melting with synthesis-driven translocation of the enzyme. In the absence of synthesis, the unwound region created by a primer-positioned RT appears to be no greater than 2 bp and does not advance along the template. Additionally, RT does not utilize ATP or any deoxynucleoside triphosphate not directly encoded by the template strand to catalyze processive duplex unwinding at a nick; nor does binding of the enzyme unwind duplex DNA in the absence of a 39 terminus. The approximate maximum chain elongation rate during strand displacement synthesis by Moloney murine leukemia virus RT falls between 0.73 and 1.5 nucleotides per s at 37 degrees C. The RNase H activity of RT does not appear to play a role in displacement synthesis; however, a 181-amino-acid C-terminal truncation of RT displays a dramatically reduced ability to catalyze synthesis through duplex DNA. Images
Explicit multistep methods in system simulation

The digital simulation of continuous-time linear time-invariant systems is based on methods for the numerical solution of differential equations. While there are many methods for the same, the transformation methods are very convenient in a systems context. In this work, the author seeks to improve the stability and accuracy properties of explicit multistep transformation methods. The second-order transformations that are derived show improved performance during simulations, confirming the theory. >
Location of argon and water in cordierite

Evaluation of X-ray powder diffraction data shows that argon atoms (radius 1·9 A) lie at the centres of the large holes in the cordierite structure. The reflection intensities for hydrous cordierite differ from those for anhydrous cordierite but to a lesser degree than those for argon-bearing cordierite. Although analysis is uncertain, it appears that the smaller water molecules (radius 1·4 A) do not occupy either the centres of the six-membered rings or the centres of the large cavities. It is possible that they may be attached to the walls of the large cavities or occur partly as hydroxyl groups in the framework. Single-crystal X-ray analysis is necessary to resolve this problem.
Characterizing the epistemological development of physics majors

Students in introductory physics courses are likely to have views about physics that differ from those of experts. However, students who continue to study physics eventually become experts themselves. Presumably these students either possess or develop more expertlike views. To investigate this process, the views of introductory physics students majoring in physics are compared with the views of introductory physics students majoring in engineering. In addition, the views of physics majors are assessed at various stages of degree progress. The Colorado learning attitudes about science survey is used to evaluate students' views about physics, and students' overall survey scores and responses to individual survey items are analyzed. Beginning physics majors are significantly more expertlike than nonmajors in introductory physics courses, and this high level of sophistication is consistent for most of undergraduate study.
Wave effects in gravitational lensing of electromagnetic radiation.

Wave effects in the gravitational lensing of electromagnetic radiation by compact objects in astrophysics are treated. In the regime where the influence of diffraction is severe, solutions of the wave equation appropriate for lensing in astrophysics (which is of the form of the Schroumldinger equation for Coulomb scattering) are obtained. In the WKB regime, previous formulations are refined and extended to the case in which a part of the source is directly behind the lensing mass. Wave effects tend to be largest for this geometry which requires that radiation at a caustic be treated. The autocorrelation function of the electric field and the related frequency dependence of the radiation are emphasized, in addition to the diffraction pattern, to measure the deviations from the solutions obtained in the approximation of geometrical optics. In contrast, gravitational lensing is independent of frequency in the usual treatment which is based upon geometrical optics. Numerical computations are performed to indicate how the wave effects depend upon the relevant parameters including especially the size of the source. Wave effects are most significant at radio frequencies and for lensing by stellar and planetary masses. The importance of wave effects is governed by the ratio of the Schwarzschild radius of the lensing mass to the wavelength of the radiation.
Analysis of Nonlinear Gene Expression Progression Reveals Extensive Pathway and Age-Specific Transitions in Aging Human Brains

Several recent gene expression studies identified hundreds of genes that are correlated with age in brain and other tissues in human. However, these studies used linear models of age correlation, which are not well equipped to model abrupt changes associated with particular ages. We developed a computational algorithm for age estimation in which the expression of each gene is treated as a dichotomized biomarker for whether the subject is older or younger than a particular age. In addition, for each age-informative gene our algorithm identifies the age threshold with the most drastic change in expression level, which allows us to associate genes with particular age periods. Analysis of human aging brain expression datasets from three frontal cortex regions showed that different pathways undergo transitions at different ages, and the distribution of pathways and age thresholds varies across brain regions. Our study reveals age-correlated expression changes at particular age points and allows one to estimate the age of an individual with better accuracy than previously published methods.
SU‐FF‐T‐43: A Planar Dose Calculation Algorithm for IMRT Quality Assurance

Purpose: To develop a fast algorithm for independent planar dose verification of IMRT plans delivered with an MLC as part of the IMRTquality assurance procedure. Methods and Materials: A fast empirical IMRT planner dose calculation algorithm was implemented. In‐air output factors were used to model the source distribution, which is used to calculate the planar fluence at the detector plane based on the projected source integration on the source plane shaped by the combined positions of the jaws and MLC. The planner dose is obtained by convolving the planner fluence with a kernel, which is modified from the published kernel by fitting to standard field profiles at the specified depth. MLC‐introduced dosimetric effects, such as leaf transmission, rounded leaf end, and tongue‐and‐groove effects were accounted for explicitly by empirical fits to measured data. The algorithm was applied to two linac models with completely different head designs: a Varian 2100 C/D with 120‐leaf MLC and an Elekta Synergy S with Beam Modulator (40‐leaf MLC with no backup jaws). The calculated planner dose distributions were compared with both the MapCHECK measurements and with calculations using a commercial planning system (Pinnacle3, version 7.6) for several clinical cases. Comparison was done using the MapCHECK software in absolute dose mode with 3% dose error and 3‐mm distance‐to‐agreement criteria. Results: The passing rate for most of the cases is above 95% with most of the failing points in the field edges. The calculation time for each field is about 5 sec using a personal laptop computer and is independent of field size.Conclusions: A fast algorithm has been developed for independent planar dose verification of IMRT plans as part of the IMRTquality assurance procedure. The algorithm was applied to two linac models with excellent results. Research sponsored by Sun Nuclear Corp.
LitLinker: capturing connections across the biomedical literature

The explosive growth in the biomedical literature has made it difficult for researchers to keep up with advancements, even in their own narrow specializations. In addition, this current volume of information has created barriers that prevent researchers from exploring connections to their own work from other parts of the literature. Although potentially useful connections might permeate the literature, they will remain buried without new kinds of tools to help researchers capture new knowledge that bridges gaps across distinct sections of the literature. In this paper, we present LitLinker, a system that incorporates knowledge-based methodologies, natural-language processing techniques, and a data-mining algorithm to mine the biomedical literature for new, potential causal links between biomedical terms. Our results from a well-known text-mining example show that LitLinker can capture these novel, interesting connections in an open-ended fashion, with less manual intervention than in previous systems.
Solvation of Biomolecules by the Soft Sticky Dipole-Quadrupole-Octupole Water Model.

The soft sticky dipole-quadrupole-octupole (SSDQO) potential energy function represents a water molecule by a single site with a van der Waals sphere and point multipoles. Previously, SSDQO was shown to give good properties for liquid water and solvation of simple ions and is faster than three point models. Here, SSDQO is assessed for solvating biologically relevant molecules having a multi-site, partial charge description. Monte Carlo simulations of ethanol, benzene, and Nmethylacetamide in SSDQO with SPC/E moments showed the water structure was as good as in SPC/E. Thus, SSDQO is potentially useful for simulations of biological macromolecules in aqueous solution.
A wireless smart grid testbed in lab

State-of-the-art Smart Grid design needs innovation in a number of dimensions: distributed and dynamic network with two-way information and energy transmission, seamless integration of renewable energy sources, management of intermittent power supplies, realtime demand response, and energy pricing strategy. To realize these, we have designed SmartGridLab, a wireless Smart Grid testbed to help the Smart Grid research community analyze and evaluate their designs and developed protocols in a lab environment.
IMMUNOCHEMICAL STUDIES ON THE CROSS-REACTIVITY BETWEEN STREPTOCOCCAL AND STAPHYLOCOCCAL MUCOPEPTIDE

Particulate mucopeptides of Group A-variant streptococci and Staphylococcus aureus , solubilized by ultrasonic treatment, give a precipitin reaction with the sera of rabbits immunized with Group A-variant streptococci. γ-G globulin antibodies have been recovered from these sera which react with the mucopeptides but not with the Group A-variant carbohydrate. The immunochemical basis for the cross-reactivity between the streptococcal and staphylococcal mucopeptides was investigated in detail. Three chemically different fractions have been isolated from enzymatic digests of staphylococcal mucopeptide and were employed as haptenic inhibitors of the precipitin reaction. A fraction consisting of the peptide moiety of mucopeptide was the strongest inhibitor, whereas the hexosamine-rich fraction was less effective. The third fraction, rich in glycine, was least effective. It is suggested that the immunologic cross-reactivity between streptococcal and staphylococcal mucopeptide is due to the fact that these two substances contain chemically similar tetrapeptides. The hexosamine polymer which is identical for both mucopeptides may also contribute to their cross-reactivity.
A pressure correction scheme for generalized form of energy-stable open boundary conditions for incompressible flows

We present a generalized form of open boundary conditions, and an associated numerical algorithm, for simulating incompressible flows involving open or outflow boundaries. The generalized form represents a family of open boundary conditions, which all ensure the energy stability of the system, even in situations where strong vortices or backflows occur at the open/outflow boundaries. Our numerical algorithm for treating these open boundary conditions is based on a rotational pressure correction-type strategy, with a formulation suitable for C 0 spectral-element spatial discretizations. We have introduced a discrete equation and associated boundary conditions for an auxiliary variable. The algorithm contains constructions that prevent a numerical locking at the open/outflow boundary. In addition, we have developed a scheme with a provable unconditional stability for a sub-class of the open boundary conditions. Extensive numerical experiments have been presented to demonstrate the performance of our method for several flow problems involving open/outflow boundaries. We compare simulation results with the experimental data to demonstrate the accuracy of our algorithm. Long-time simulations have been performed for a range of Reynolds numbers at which strong vortices or backflows occur at the open/outflow boundaries. We show that the open boundary conditions and the numerical algorithm developed herein produce stable simulations in such situations.
The effects of the elimination of rehearsal on primacy and recency

The role of rehearsal in free recall was investigated by varying the amount of rehearsal during learning. An intentional learning condition (INT) and an intentional learning condition with a subsidiary task (INT-T) compared recall under conditions of full and reduced rehearsal, respectively. An incidental learning condition (INC) was also used to examine recall with rehearsal eliminated. Performance under INT-T revealed the usual serial position effect, but overall recall was reduced relative to INT. Performance under INC was described by the presence of recency but the absence of primacy. The results question the necessity of a rehearsal buffer mechanism as an explanation of recency.
Quality of experience for HTTP adaptive streaming services

The growing consumer demand for mobile video services is one of the key drivers of the evolution of new wireless multimedia solutions requiring exploration of new ways to optimize future wireless networks for video services towards delivering enhanced quality of experience (QoE). One of these key video enhancing solutions is HTTP adaptive streaming (HAS), which has recently been spreading as a form of Internet video delivery and is expected to be deployed more broadly over the next few years. As a relatively new technology in comparison with traditional push-based adaptive streaming techniques, deployment of HAS presents new challenges and opportunities for content developers, service providers, network operators and device manufacturers. One of these important challenges is developing evaluation methodologies and performance metrics to accurately assess user QoE for HAS services, and effectively utilizing these metrics for service provisioning and optimizing network adaptation. In that vein, this article provides an overview of HAS concepts, and reviews the recently standardized QoE metrics and reporting framework in 3GPP. Furthermore, we present an end-to-end QoE evaluation study on HAS conducted over 3GPP LTE networks and conclude with a discussion of future challenges and opportunities in QoE optimization for HAS services.
mTORC1-dependent and -independent regulation of stem cell renewal, differentiation, and mobilization

The Tuberous Sclerosis Complex component, TSC1, functions as a tumor suppressor via its regulation of diverse cellular processes, particularly cell growth. TSC1 exists in a complex with TSC2 and functions primarily as a key negative regulator of mammalian target of rapamycin complex 1 (mTORC1) signaling and protein synthesis, although the TSC1/TSC2 complex also shows mTORC1-independent outputs to other pathways. Here, we explored the role of TSC1 in various aspects of stem cell biology and dissected the extent to which TSC1 functions are executed via mTORC1-dependent versus mTORC1-independent pathways. Using hematopoietic stem cells (HSCs) as a model system, we demonstrate that somatic deletion of TSC1 produces striking stem cell and derivative effector cell phenotypes characterized by increased HSC cell cycling, mobilization, marked progressive depletion, defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. On the mechanistic level, we further establish that TSC1 regulation of HSC quiescence and long-term repopulating potential and hematopoietic lineage development is mediated through mTORC1 signaling. In contrast, TSC1 regulation of HSC mobilization is effected in an mTORC1-independent manner, and gene profiling and functional analyses reveals the actin-bundling protein FSCN1 as a key TSC1/TSC2 target in the regulation of HSC mobilization. Thus, TSC1 is a critical regulator of HSC self-renewal, mobilization, and multilineage development and executes these actions via both mTORC1-dependent and -independent pathways.
Bone: Does TSH concentration influence skeletal health?

Controversy surrounds the skeletal consequences of altered thyroid function. According to the latest report from the Tromso population survey, however, variations of serum TSH concentration that remain within the normal range do not greatly influence BMD.
Computer simulation in pores with rectangular cross-sections

Abstract Monte Carlo computer simulations are reported for the sorption of Ar at 90 K in several pores of different shapes. In all cases, the pore walls were modeled as perfectly flat graphitic planes that have been assembled to form pores with rectangular cross-sections characterized by having one dimension fixed at a value that allows four layers of argon in the full pore (with one exception). The second dimension of the rectangle was varied from four to eight to 12 argon atom diameters to infinite (simple slit). A pore having dimensions of 7×7 argon atoms was also studied. It is shown that the presence of corners in these pores has a profound effect upon their adsorptive behavior; that adsorption in the corners can be quantitatively treated in terms of one-dimensional theory; and that the remaining adsorption on the walls gives monolayer packings with liquid-like two-dimensional densities. The effect of pore shape upon capillary condensation and hysteresis is also investigated.
Effect of Indomethacin on Blood Pressure Lowering by Captopril and Losartan in Hypertensive Patients

NSAIDs are known to attenuate the effects of some antihypertensive medications. It is not known whether the new class of angiotensin II receptor antagonists is similarly affected. We conducted a multicenter study assessing the effect of indomethacin on the antihypertensive effects of losartan and captopril. After 4 weeks of placebo washout, hypertensive patients received 6 weeks of active antihypertensive therapy with either 50 mg losartan once daily (n=111) or 25 mg captopril twice daily for 1 week, which was increased to 50 mg twice daily for 5 weeks (n=105). This was followed by 1 week of concomitant therapy with indomethacin (75 mg daily). The primary outcome measure was the change in mean 24-hour ambulatory diastolic blood pressure after the addition of indomethacin. Both captopril and losartan significantly lowered ambulatory diastolic blood pressure (losartan -5.3 mm Hg, P:<0.001; captopril -5.6 mm Hg, P:<0.001) after 6 weeks of therapy. Indomethacin significantly attenuated the 24-hour ambulatory diastolic blood pressure for both losartan (2.2 mm Hg, P:<0.05) and captopril (2.7 mm Hg, P:<0.001) and also attenuated the effect of captopril on trough sitting diastolic blood pressure. Changes in daytime diastolic blood pressure (7:00 AM to 11:00 PM) were similar to the 24-hour response in both groups. Nighttime diastolic blood pressure (11:01 PM to 6:59 AM) was significantly attenuated in captopril-treated patients (2.0 mm Hg, P:<0.05), but losartan was unaffected (0.4 mm Hg). Thus, concurrent treatment with indomethacin similarly attenuates the 24-hour antihypertensive response to losartan and captopril.
From crisis to community: the Pittsburgh oil spill

The interdependence of metropolitan communities generates a stubborn paradox in crisis. The infrastructure created to link local systems in productive action operates, with equal facility, to transmit failure, distortion and neglect. This function serves to escalate failure in a single system to failure in multiple systems in the metropolitan community. This article examines the effects of interdependence in escalating the 1988 tank collapse at the Ashland Oil Com pany's storage site on the Monongahela River near Pittsburgh, Pennsylvania, to a full-scale crisis spanning two weeks and three states, and affecting ad versely the lives of approximately 830,000 people. An interactive information system is proposed as an alternative method of reducing risk and facilitating response to minimize crisis in metropolitan communities.