cssi/SciSciGPT-SciSciNet huggingface dataset:
The Surgical Knowledge "Growth Curve": Predicting ABSITE Scores and Identifying "At-Risk" Residents

OBJECTIVE Resident performance on the American Board of Surgery In-Training Examination (ABSITE) is used for evaluation of surgical knowledge and guides resident selection for institutional remediation programs. Remediation thresholds have historically been based on ABSITE percentile scores; however, this does not account for predictors that can impact a resident's exam performance. We sought to identify predictors of yearly ABSITE performance to help identify residents “at-risk” for performing below their expected growth trajectory. DESIGN The knowledge of the residents, as measured by standardized ABSITE scores, was modeled as a function of the corresponding postgraduate year via a linear mixed effects regression model. Additional model covariates included written USMLE-1-3 examination scores, gender, number of practice questions completed, and percentage correct of practice questions. For each resident, the predicted ABSITE standard score along with a 95% bootstrap prediction interval was obtained. Both resident-specific and population-level predictions for ABSITE standard scores were also estimated. SETTING The study was conducted at a single, large academic medical center (Massachusetts General Hospital, Boston, MA). PARTICIPANTS Six years of general surgery resident score reports at a single institution between 2014 and 2019 were deidentified and analyzed. RESULTS A total of 376 score reports from 130 residents were analyzed. Covariates that had a significant effect on the model included USMLE-1 score (PGY1: p = 0.013; PGY2: p = 0.007; PGY3: p = 0.011), USMLE-2 score (PGY1: p CONCLUSION Performance on USMLE-1 and -2 examinations, male gender, and number of practice questions completed were positive predictors of ABSITE performance. Creating residency-wide knowledge growth curves as well as individualized predictive ABSITE performance models allows for more efficient identification of residents potentially at risk for poor ABSITE performance and structured monitoring of surgical knowledge progression.
Exemplary and Unacceptable Workplace Communication Skills

Thematic analysis of interviews with 22 managers highlight their perspectives on exemplary and unacceptable workplace communication skills. Exemplary skills were perceived to be relatability, docum...
Papers in honor of Syd Anderson’s contributions to Bolivian and Neotropical Mammalogy

The current issue of Therya includes a number of papers honoring the legacy and notable contributions of Dr. Sydney Anderson (1927-2018) to Bolivian and Neotropical mammalogy. “El Doc,” as he was warmly referred to by hordes of Bolivians scientists and students, played a central role in the coming of age of mammalogy in Bolivia. He influenced many aspects of this development, from using his own personal funds to purchase traps and museum cases for the then mammal collection of the Bolivian Museum of Natural History, to serving as a towering example of an unassuming mammalogist who loved and honored his science so much that he enjoyed going out camping and trapping in remote areas of Bolivia for almost three decades from 1964 to 1992, and until he was well into his late 60s.
Multiplicity of X-Ray-selected T Tauri Stars in Chamaeleon*

We report on a multiplicity survey of a sample of X-ray–selected young stars in the Chamaeleon association. We used speckle interferometry and direct imaging to find companions in the separation range 013–6''. After correction for chance alignment with background stars, we find a multiplicity (number of binaries or multiples divided by number of systems) of 14.0% ± 4.3% and a companion-star frequency (number of companions divided by number of systems) of 14.7% ± 5.1%. Compared with solar-type main-sequence stars, the companion-star frequency is lower by a factor of 0.61 ± 0.27. This is remarkably different from the high multiplicity found in the Taurus-Auriga star-forming region and for T Tauri stars in Chamaeleon known before ROSAT. We find only a few binaries with projected separations of more than 70 AU, also in contrast to the results for stars known before ROSAT. This indicates that the X-ray–selected stars belong to a different population than the stars known before ROSAT, a hypothesis further supported by their Hipparcos distances and proper motions.
Meta-analysis and meta-regression of outcomes for adult living donor liver transplantation versus deceased donor liver transplantation

Prior single center or registry studies have shown that living donor liver transplantation (LDLT) decreases waitlist mortality and offers superior patient survival over deceased donor liver transplantation (DDLT). The aim of this study was to compare outcomes for adult LDLT and DDLT via systematic review. A meta-analysis was conducted to examine patient survival and graft survival, MELD, waiting time, technical complications, and postoperative infections. Out of 8600 abstracts, 19 international studies comparing adult LDLT and DDLT published between 1/2005 and 12/2017 were included. U.S. outcomes were analyzed using registry data. Overall, 4571 LDLT and 66,826 DDLT patients were examined. LDLT was associated with lower mortality at 1, 3, and 5 years posttransplant (5-year HR 0.87 [95% CI 0.81-0.93], p < .0001), similar graft survival, lower MELD at transplant (p < .04), shorter waiting time (p < .0001), and lower risk of rejection (p = .02), with a higher risk of biliary complications (OR 2.14, p < .0001). No differences were observed in rates of hepatic artery thrombosis. In meta-regression analysis, MELD difference was significantly associated with posttransplant survival (R2 0.56, p = .02). In conclusion, LDLT is associated with improved patient survival, less waiting time, and lower MELD at LT, despite posing a higher risk of biliary complications that did not affect survival posttransplant.
A Scoping Review of Burnout in Neurosurgery.

Background Burnout is a negative workplace syndrome of emotional exhaustion, cynicism, and perceived professional inefficacy that risks the patient-provider relationship, patient care, and physician well-being. Objective To assimilate the neurosurgical burnout literature in order to classify burnout among domestic and international neurosurgeons and trainees, identify contributory factors, and appraise the impact of wellness programs. Methods A scoping review identified the available literature, which was reviewed for key factors related to burnout among neurosurgeons. Two researchers queried PubMed, Embase, Google Scholar, Cochrane, and Web of Science for articles on burnout in neurosurgery and reduced 1610 results to 32 articles. Results A total of 32 studies examined burnout in neurosurgery. A total of 26 studies examined prevalence and 8 studies detailed impact of wellness programs. All were published after 2011. Burnout prevalence was measured mostly through the Maslach Burnout Inventory (n = 21). In 4 studies, participants defined their own understanding of "burnout." Domestically, burnout prevalence was 11.2% to 67% among residents and 15% to 57% among attendings. Among trainees, poor operative experience, poor faculty relationships, and social stressors were burnout risks but not age, sex, or marital status. Among attendings, the literature identified financial or legal concerns, lack of intellectual stimulation, and poor work-life balance as risks. The impact of wellness programs on trainees is unclear but group exercises may offer the most benefit. Conclusion Noticeable methodological differences in studies on trainee and attending burnout contribute to a wide range of neurosurgery burnout estimates and yield significant knowledge gaps. Environment may have greater impact on trainee burnout than demographics. Wellness programs should emphasize solidarity.
Can We Use Commercial Mobile Apps Instead of Research Mobile Apps in Healthcare Research

Scientific research has been at the front line of unlocking many innovations and opportunities as well as creating the evidence for methods and technologies. Similarly, there has been an increasing effort on mobile health research to tackle healthcare communication and access problems at individual and population level. However, there have been a number of problems limiting the progress of mobile health research. The major road blocker has been the sustainability and reach of RMA in real world use. This created a disparity between academia and industry in the development of digital health solutions and improving health outcomes for populations (1). Research for developing apps and creating evidence take time and heavily depend on research fund within pre-determined project period. Eventually, completing a research app prototype might take years. Whereas, the industry has been on the fast track in development, as creating sustainable pipeline for emerging products and apps. Inevitable systemic differences have been mostly the reason to apart the path of these two domains. Even though there has been occasional high-level convergence between industry and academia (e.g., Apple Heart Study with Stanford U) (2), the disparity mostly resulted as an increase in digital waste and lack in long-term improvements in digital health and impact on health outcomes. This problem has not been one-sided, it also affected CMA adversely, as most of the academic findings remained underutilized by the industry. Earlier studies showed that many of commercial health apps were not sufficiently generating evidence or using the science in design, which impact the utility of their apps and health outcomes (3, 4). The symbiotic relationship of RMA and CMA is apparently necessary regarding the benefits for research and industry. So, the question is: “How could we utilize CMA in healthcare research through sustainable and scalable apps that can inform the science more effectively?”
Sexual enslavement of girls and women worldwide

Foreword by Judy Kuriansky Preface Abbreviations Section Part I: Sexual Slavery of Women in Context Chapter 1:. Scope of the Problem Overview Chapter 2.: Conditions Supporting Sexual Slavery Section Part II: Types of Sexual Slavery Chapter 3: Sex Trafficking Chapter 4: War-Induced Sexual Slavery Chapter 5: Religious Sexual Slavery Chapter 6.: Forced Marriage Chapter 7.: Sexual Servitude Section Part III: Attempts to Reduce or Eliminate Sexual Slavery Chapter 8.: Success Stories: Policies and Legislative Chapter 9.: Consequences of Sexual Slavery and Trafficking of Girls and Women Chapter 10:. Initiatives to Stop Sexual Slavery: International, National, and Legislative Appendices Appendix A1: Convention on the Elimination of All Forms of Discrimination against Women Appendix 2B: Convention on the Rights of the Child Appendix 3C: U.N. Declaration on the Elimination of Violence Against Women 1993 Appendix 4D: PROTOCOL TO PREVENT, SUPPRESS AND PUNISH TRAFFICKING IN PERSONS, ESPECIALLY WOMEN AND CHILDREN, SUPPLEMENTING THE UNITED NATIONS CONVENTION AGAINST TRANSNATIONALORGANIZED CRIME Glossary References Index List of Illustrations Figure 1. The interaction of factors associated with sexual slavery Figure 2. Global trafficking patterns by source and destination countries
Evolution and Energization of Energetic Electrons in the Inner Magnetosphere

In this paper we present a review of what we know about the evolution and energization of energetic electrons in the inner magnetosphere. We emphasize what we have learned since the review by Friedel et al. [17] that discussed in detail the possible acceleration mechanisms for these electrons. The primary result has been a greater focus on local acceleration processes with significant new evidence that points to processes that are acting in the region between GPS and geosynchronous altitudes. In addition to reviewing the most recent results we also use as an example the magnetosphere’s energetic electron responses to a series of storms that occurred in the July 16–25, 2004 period. The storms had gradually increasing magnitude, in terms of their minimum DST of − 80, − 101, − 148, and − 197 nT. We followed the penetration and enhancements of the electrons as a function of L value using the HEO3 observations. We found that the two smallest storms did not cause relativistic electron enhancements for L 130 and > 230 keV down to L ∼3. 0. The two largest events cause electron enhancements at all energies from > 130 keV to > 3 MeV down to L ∼2. 5. We found that the Cluster IES observations of the source populations in the pre midnight plasma sheet were quite intense with strong field aligned distributions during the early main phase of the storm on July 24. The combined results indicate that these early main phase electron fluxes at Cluster may be directly linked to the rapid response of electrons at low L observed by HEO3 and could have been the source for the < 1 MeV fluxes observed there.
The Neurobiology and Physiology of Emotions: A Developmental Perspective

This essay discusses the physiological and neural activity associated with emotion processes, with a focus on the development of this activity in children. We review some conceptual issues about the distinctions between the components of emotion, including the physiology associated with emotions themselves, attempts to regulate emotions, and trait or state patterns of responding. Foundational work examining autonomic nervous system activity is summarized, and we highlight recent work that attempts to investigate emotion processes in multiple systems. We then suggest that two fruitful avenues of future research include the examination of the neurobiology and physiology of social emotions, and further investigation into the temporal dynamics of emotion processes. Keywords: emotion; children; autonomic nervous system; brain; HPA ; multilevel analysis; dynamics
WHAT SYMBIONTS, PATHOGENS AND CELL FUSIONS TEACH US ABOUT EVOLUTION

Over a half century of molecular genetics has transformed our view of how genomes operate in the cells of living organisms. Instead of the DNA-centric view in which the genome determines the properties of cells and organisms, we understand today that cells use their genomes as read-write (RW) data-storage systems. The ability of cells to restructure their genomes is critical to episodes of evolutionary change, where new genomic structures become necessary to survive and proliferate in a modified ecology. Contrary to conventional evolutionary views, the genome record teaches us that many of these changes involve intercellular and intracellular horizontal DNA transfer, cell fusions, novel symbiotic associations and unusual fertilization events. Illustrations of critical genome sequencing data come from all kingdoms of life (bacteria, archaea and eukarya) and from both microbes and larger organisms. Cell sensory and regulatory networks as well as the molecular toolkit for genome restructuring are central to a modern 21st Century view of the evolutionary process. The ability of cells to regulate genome restructuring at the epigenetic and other levels plays a key role in the timing of evolutionary events. It is likely that the complementary ability of cells to target change within the genome has played a significant part in the origination of evolutionary novelties, ranging from new protein domains to entire morphogenetic circuits. These ideas serve as the basis for a new way of thinking about the evolutionary process that both integrates ecological disruptions and suggests an innovative research agenda for the new century.
A versatile setup using femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering

We report a versatile setup based on the femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman scattering. The setup uses a femtosecond Ti:Sapphire oscillator source and a folded 4f pulse shaper, in which the pulse shaping is carried out through conventional optical elements and does not require a spatial light modulator. Our setup is simple in alignment, and can be easily switched between the collinear single-beam and the noncollinear two-beam configurations. We demonstrate the capability for investigating both transparent and highly scattering samples by detecting transmitted and reflected signals, respectively.
Arrival to and location of Bufo woodhousei in the breeding pond: effect on the operational sex ratio

Individual male and female Bufo woodhousei spent only two or three nights of the several week breeding season in the pond. In spite of the continual arriving and leaving of individuals the operational sex ratio (the number of females available to mate/number of males attempting to mate) varied little, either temporally across the breeding season or spatially between male groups in the pond. Male body size distributions also varied little between nights and between male groups.
Aspiration pneumonia. A clinical and experimental review.

Abstract The history, clinical features, pathophysiology, and treatment of aspiration pneumonia have been briefly reviewed. Emphasis has been placed on the discussion of the aspiration of liquid gastric contents of low pH. Comments have been made on the efficacy of present therapy and areas of future clinical and experimental investigation explored.
Relationship between expression of hepatic metallothionein and sublethal stress in channel catfish following acute exposure to copper sulphate

Abstract Copper sulphate is frequently used as a general biocide in the aquacultural industry. The acute effects of copper sulphate on sublethal endpoints of stress and tissue damage in channel catfish have not been explored previously. Consequently, the purpose of this study was to examine the effects of a therapeutically relevant dose of copper sulphate on plasma cortisol, hepatic metallothionein (MT) expression, hepatic copper content and plasma concentrations of aspartate aminotransferase (AST). Exposure of prespawn juvenile catfish to 1.7 mg/l as copper sulphate (326±9.4 μg/l copper; 175–180 mg/l CaCO 3 ; pH 7.45) led to time-dependent increases in hepatic MT expression, hepatic copper content as well as plasma cortisol concentrations. Exposure to a 1 h confinement stress led to a redistribution of copper to the liver but no significant increases in hepatic MT or plasma cortisol after 23 h. Neither stress nor copper exposure caused liver damage as measured by AST. The parallel expression of hepatic MT with plasma cortisol and hepatic copper residues suggests that MT may serve as a useful indicator of acute stress and acute exposure to copper sulphate in channel catfish.
Career paths and practice patterns of global emergency medicine physicians: a cross-sectional survey.

Abstract Background Increasing numbers of emergency medicine (EM) residents and fellows are completing additional training with the intention of pursuing careers in global emergency medicine (GEM). At the same time, many academic emergency departments (EDs) are investing in the development of GEM divisions and global/international EM fellowship programs. However, the path for a successful career in this subspecialty has still not been defined. Objective Our aim was to survey emergency physicians engaged in GEM in order to characterize their practice patterns and career paths, and to identify barriers to a successful career. Methods An online survey assessing demographics, timing and content of work, financing and barriers, and academic productivity was deployed to emergency physicians. Descriptive statistics were analyzed using STATA software. Results A total of 116 attending emergency physicians responded. Female respondents tended to be younger (51% vs. 27%; p = 0.012). Younger respondents were more likely to have completed advanced GEM training (20% vs. 7%; p = 0.037). Most (73%) respondents spent fewer than 3 months annually abroad. Self funding was the most common (47%) source of funding, while only 16% reported receiving grant support. Lack of time and funding were the most commonly encountered barriers to a career in GEM (64% and 55%, respectively). Conclusions Our survey provides an understanding of the amount of time that emergency physicians in GEM spend abroad and the types of activities in which they are currently engaged, as well as the barriers that need to be overcome in order to achieve fulfilling careers in this field.
Investigating Trauma History and Related Psychosocial Deficits of Women in Prison: Implications for Treatment and Rehabilitation

The present study was an investigation into the needs of women in prison. The purpose was to explore women's rehabilitation needs and assess whether correctional programs and policies are promoting rehabilitation. Both quantitative and qualitative data were collected for descriptive analysis. A total of 17 incarcerated women from a medium-security prison were surveyed; 11 of those inmates also agreed to be interviewed. Results indicated significant history of trauma as well as significant psychosocial deficits typically associated with trauma. Despite an apparent need for programming addressing trauma, qualitative interviews revealed a shortage of services addressing trauma victimization and institutional policies with the potential to further harm trauma survivors.
Synthesis of phosphonate derivatives of myo-inositol for use in biochemical studies of inositol-binding proteins.

Abstract Phospholipids containing the inositol headgroup (phosphoinositides) serve as membrane storage forms of a family of messenger molecules that transmit signals in cells. In this study a general synthesis of myo -inositol phosphate derivatives in which the posphorus oxygen bond is replaced with a phosphorus carbon bond (i.e. phosphonates) is presented. Four specific examples of phosphonate analogs of phosphatidylinositol (PI) are prepared which have a single alkyl chain in place of the diacylglycerol. These derivatives are stable in neutral and alkaline solutions and are designed for use in biochemical studies of PI-specific phospholipases C and other enzymes involved in the phosphoinositide signal transduction pathway.
Enriching the web by modeling reading difficulty

The ability to read and understand a text would seem to be a basic aspect of interacting with a rich information source like the Web, yet little is currently known about the nature of the Web, its users, and how users interact with content when seen through the lens of reading difficulty. For example, a document isn't relevant to a person's information need - at least, not immediately - if they can't understand it, yet Web search engines have traditionally ignored the problem of finding or providing content at the right level of difficulty as an aspect of relevance. I'll give an overview of recent research that shows how computing and applying metadata based on text readability at Web scale opens up new and sometimes surprising possibilities for enriching our interactions with the Web: from personalizing Web search results, to predicting user and site expertise, to estimating searcher motivation. I'll also highlight future challenges and opportunities in improving text readability analysis, particularly in light of the rapidly growing interest in large-scale applications for online education.
APPLICATION OF LEARNING THEORY TO AN ARTIFICIAL NEURAL NETWORK THAT DETECTS INCIPIENT FAULTS IN SINGLE-PHASE INDUCTION MOTORS

The generalization ability of a neural network in a specific application is of interest to many neural network designers. In this paper, learning theory is applied to a neural network used for incipient fault detection in single-phase induction motors. This paper will show that learning theory can help determine the proper number of training examples needed to reach a specific performance level, so that excessive and unnecessary training examples can be avoided. Comparisons of the results of learning theory and Monte Carlo estimate are presented, showing that learning theory is a useful and reliable tool to obtain information about the training process of a given neural network.
Voluntary exercise, food intake, and plasma metabolites in streptozotocin-diabetic Syrian hamsters

Diabetes mellitus was induced in Syrian hamsters by treatment with streptozotocin. The efficacy of and survival from this treatment are compared across several drug regimens, and in exercising versus sedentary hamsters. Stable diabetes, with plasma glucose levels typically below 400 mg/dl, is accompanied by a decrease of approximately 50% in voluntary wheel running in a 14L:10D cycle. Wheel running in diabetics is, however, almost completely abolished in continuous light. The diabetic hamsters are hyperphagic on chow, eating about 60% more than controls, exclusively by increasing the size of individual meals. Their intake is normalized on a high fat diet. The high fat diet greatly exacerbates the extant ketonemia in diabetics, and produces hypertriglyceridemia. Exercise has no apparent effect on plasma metabolic fuels of diabetic hamsters.
Is personalization of care coming to pancreatic oncology

The results of a phase II trial evaluating adjuvant treatment using a novel way of administering gemcitabine with radiation in patients with resected pancreatic cancer are presented in this issue of the Annals of Surgical Oncology. The trial was designed to evaluate local tumor control as the primary endpoint, using historical local tumor control rates of less than 60 % derived from results reported from cooperative group trials and seeking to show a 2-year local tumor control rate of over 80 % with this novel regimen. The authors reported that the local tumor control rate was apparently improved, without impacting overall survival. Thus, although the primary endpoint was met, there was no identifiable improvement in outcome. As the authors have concluded, future trials should focus on improving systemic disease control due to the high rate of distant metastatic disease in these patients. Adjuvant trials should be designed with overall survival as the primary endpoint. The use of local tumor control as a primary endpoint is problematic in pancreatic cancer for several reasons. Local tumor control is necessary but not sufficient to cure a patient of pancreatic cancer due to the competing risk of distant metastatic disease. Even if the local tumor is controlled, most patients will die of distant disease. As distant disease control is improved in the future with the development of novel systemic therapies, the impact of local tumor recurrence on overall survival could be greater. Until that happens, local tumor control will have a modest impact on overall survival even in the most highly selected patients. Another problem is the heterogeneity of patient selection and surgical quality in cooperative group trials as well as the lack of consistency in identifying and reporting local disease recurrence, which makes the historical local tumor control rate difficult to define. Although clearly there have been many studies that have reported high rates of local tumor recurrence after pancreaticoduodenectomy, the use of chemoradiation is controversial. Patients with resected pancreatic cancer should be enrolled on the current Radiation Therapy Oncology Group (RTOG)-led adjuvant trial, RTOG/INT 0848. That trial randomizes patients to receive gemcitabine with or without erlotinib for five cycles followed by a second randomization to chemoradiation or a sixth cycle of chemotherapy. Off-protocol, the preferred standard treatment is initial gemcitabine for 4‐6 cycles followed by consideration of chemoradiation. The sequencing strategy of chemotherapy followed by chemoradiation optimizes the impact of systemic therapy and reserves chemoradiation for those patients who are most likely to benefit. Given what we know about the genomic heterogeneity of pancreatic tumors, personalization of care should have the highest priority. Thus far, surgical pathology specimens from randomized adjuvant trials have proven to be the best source of tissue for correlative studies in pancreatic cancer.
Clinical value of minor responses after 4 doses of rituximab in Waldenström macroglobulinaemia: a follow-up of the Eastern Cooperative Oncology Group E3A98 trial.

Waldenstrom macroglobulinaemia is a low-grade, lymphoplasmacytic lymphoma that is responsive to rituximab. We report the role of a minor response in predicting overall outcomes. We extended follow-up of a previously described cohort (n = 69) treated with 4 weekly doses of rituximab and observed durable responses (median time to progression, 30 months; 5-year survival rate, 66%). Patients achieving a minor response [25-50% immunoglobulin M (IgM) reduction] appeared to do as well as those achieving an objective response (>50% IgM reduction), which suggests that more aggressive or intensive therapy for minor responders is not required. Future studies of Waldenstrom macroglobulinaemia should report minor responses because they are associated with clinically meaningful benefits. This trial was registered at http://www.clinicaltrials.gov as #NCT00005609.
How Do Religious Groups Respond to Class and Inequality?: Religion, Socioeconomics, and Political Behavior in the 2000 Election

Using a county-level population analysis, the author examines whether the interaction between religious groups and class and inequality predict voter turnout and voter preference for George W. Bush in the 2000 presidential election. Results indicate that for counties with high densities of mainline Protestants, lower income, and lower education meant depressed voter turnout and higher Bush support; with high densities of Jewish adherents, lower income yielded elevated voter turnout, while lower income along with less education equated with less Bush support; with high densities of Catholics, lower income meant higher voter turnout; with high densities of Evangelicals, lower income yielded depressed voter turnout; however, lower income and less education correlated with less Bush support. These patterns held for county income inequality when median income was controlled. The results challenge the perception that Evangelical groups in lower-SES regions persuaded members and their acquaintances to vote again...
Cost-effectiveness of digital subtraction angiography in the setting of computed tomographic angiography negative subarachnoid hemorrhage.

Background Recent studies have documented the high sensitivity of computed tomography angiography (CTA) in detecting a ruptured aneurysm in the presence of acute subarachnoid hemorrhage (SAH). The practice of digital subtraction angiography (DSA) when CTA does not reveal an aneurysm has thus been called into question. Objective We examined this dilemma from a cost-effectiveness perspective by using current decision analysis techniques. Methods A decision tree was created with the use of TreeAge Pro Suite 2012; in 1 arm, a CTA-negative SAH was followed up with DSA; in the other arm, patients were observed without further imaging. Based on literature review, costs and utilities were assigned to each potential outcome. Base-case and sensitivity analyses were performed to determine the cost-effectiveness of each strategy. A Monte Carlo simulation was then conducted by sampling each variable over a plausible distribution to evaluate the robustness of the model. Results With the use of a negative predictive value of 95.7% for CTA, observation was found to be the most cost-effective strategy ($6737/Quality Adjusted Life Year [QALY] vs $8460/QALY) in the base-case analysis. One-way sensitivity analysis demonstrated that DSA became the more cost-effective option if the negative predictive value of CTA fell below 93.72%. The Monte Carlo simulation produced an incremental cost-effectiveness ratio of $83 083/QALY. At the conventional willingness-to-pay threshold of $50 000/QALY, observation was the more cost-effective strategy in 83.6% of simulations. Conclusion The decision to perform a DSA in CTA-negative SAH depends strongly on the sensitivity of CTA, and therefore must be evaluated at each center treating these types of patients. Given the high sensitivity of CTA reported in the current literature, performing DSA on all patients with CTA negative SAH may not be cost-effective at every institution.
Viscoelastic Properties of Amorphous Polymers. 7. Changes of the Anomalous Behavior of Low Molecular Weight Polystyrene with the Addition of a Diluent

Torsional shear measurements of the recoverable creep compliance of a 54.7% solution of a narrow molecular weight distribution polystyrene of low molecular weight, 4000, in tri-m-tolyl phosphate ar...
Mode selection behavior of VHF thermal-piezoresistive self-sustained oscillators

The work demonstrates performance of thermal-piezoresistive self-sustained oscillators in both vacuum and ambient air conditions, up to 161MHz with AC peak-to-peak voltages of up to 44mV. The devices are of an I-shaped geometry fabricated from 1.6-1.9μm thick n-type silicon. While strong resonance is demonstrated in their intended in-plane longitudinal structural mode (gm up to -238 μA/V), the device oscillation was verified by laser vibration sensing to occur in a different mode. Finite element simulation suggests that the longitudinally symmetric flexural mode is the mode of oscillation.
Oxygen Preference in the Spring Cavefish, Chologaster agassizi

Abstract Chologaster agassizi exhibits a preference for high over low oxygenated water; however, the cavefish does not discriminate between oxygen concentrations of 2 mg/l or less, whether the two concentrations are relatively high or low. The tolerance point for oxygen preference appears to be near 6 mg/l with higher concentrations giving no observable preference. The stimulus to avoid light is more pronounced than the stimulus to select against low oxygen conditions. The reactions of the cavefish to oxygen conditions appear to be attributed to the fish sensing the unfavorable nature of the water and searching for a more desirable area. Included among the intrinsic factors involved in the migration of Chologaster from the cave to the epigean environment may be the preference for dark and high oxygen conditions.
Comparison of fracture behavior of nylon 6 versus an amorphous polyamide toughened with maleated poly(ethylene-1-octene) elastomers

Abstract The fracture behavior of an amorphous polyamide (Zytel 330 from DuPont), a-PA, and nylon 6 toughened by maleated poly(ethylene-1-octene) elastomers are reported. The deformation mechanisms during fracture were verified by examining an arrested crack tip and the surrounding regions using transmission electron microscopy analysis. a-PA blends show higher levels of impact strength and lower ductile–brittle transition temperatures than nylon 6 blends. Fracture toughness, characterized by both linear elastic fracture mechanics techniques in terms of the critical strain energy release rate, G IC , and the essential work of fracture methodology, i.e. the limiting specific fracture energy, u o , and the dissipative energy density, u d , using thick (6.35 mm) samples with sharp notches, depends on ligament length, rubber content, rubber particle size and test temperature. In general, a-PA blends show larger values of u d than do nylon 6 blends while the opposite is seen for u o . The amorphous polyamide shows a similar critical upper limit on rubber particle size, or interparticle distance, for toughening as the semi-crystalline nylon 6; thus, it is clear that the crystal morphology around the rubber particles must not be the dominant cause of this critical size scale. The deformation mechanisms involved include cavitation of rubber particles followed by some crazing and then massive shear yielding of the matrix.
Au/In/Pd/Te/Pd ohmic contact to n-GaSb

An Au/In/Pd/Te/Pd ohmic contact scheme has been developed to n-GaSb (n/spl sime/10/sup 18/ cm/sup -3/). Annealed at 250 and 400/spl deg/C, this contact scheme exhibits excellent electrical properties (contact resistivity <10/sup -6/ /spl Omega/-cm/sup 2/) and good thermal stability. The surface and interface morphologies were investigated using a scanning electron microscope (SEM). The ohmic contact formation mechanism is also proposed.
Condensed-matter physics: Transitions on triangles.

An exquisitely sensitive technique shows that a magnetic field only a few hundred times greater than Earth's can bring an exotic phase of matter known as a quantum spin liquid to an ordered magnetic state.
Genesis and Evolution of the 1997-98 El Niño

The 1997–98 El Nino was, by some measures, the strongest on record, with major climatic impacts felt around the world. A newly completed tropical Pacific atmosphere-ocean observing system documented this El Nino from its rapid onset to its sudden demise in greater detail than was ever before possible. The unprecedented measurements challenge existing theories about El Nino–related climate swings and suggest why climate forecast models underpredicted the strength of the El Nino before its onset.
STR‐PEM fuel cell as a reactor building block

The dynamics of the stirred tank reactor polymer electrolyte membrane (STR-PEM) fuel cell arise from the balance between water production and water removal within the cell. This results in STR-PEM fuel cell steady-state multiplicity, remarkably analogous to that of an autocatalytic exothermic STR. Model flooding effects in the cathodeside catalyst/gas diffusion layer by accounting for relevant mass-transport processes is presented. We use the resulting STR-PEM fuel cell model as a building block to construct approximations of more conventional integral (plug flow) type fuel-cell reactors. This approach bypasses more complicated, distributed gas diffusion layer models. Connecting several STR-PEM fuel cells in series, the effects of four operating parameters (temperature, external load resistance, inlet hydrogen and inlet oxygen flow rates) on the current evolution in each tank can be monitored and rationalized. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Low frequency skeletal vibrations in solid n-alkyl bromides by neutron inelastic scattering: n-pentyl, n-hexyl, n-heptyl and n-octyl bromides

Abstract The skeletal bending and torsional fundamentals in solid n -pentyl, n -hexyl, n -heptyl and n -octyl bromides are measured by the technique of cold neutron inelastic scattering. The observed frequencies are assigned on the basis of normal coordinate calculations using simplified valence force fields. The frequencies of the end-methyl torsion were observed about 240 cm −1 , virtually unchanged from that of n -paraffins. The observed and calculated data were correlated with ν 5 and ν 9 dispersion curves of polymethylene by making suitable phase-difference assignments.
On a vibronic origin for the diffuse band spectrum

Duley (1982) has proposed that many of the diffuse interstellar bands in the wavelength interval 542-677 nm arise from vibronic transitions of Cr (3+) ions in MgO grains. No explanation has been offered for the fact that as many as 85 of the possible 108 transitions of this system have not been observed in the interstellar medium. Moreover, the relative intensities of the diffuse bands which are observed appear to be inconsistent with their assignment. It is therefore concluded that this model is not consistent with the observations.
Deep brain stimulation facilitates memory in a model of Alzheimer’s disease

Based on evidence suggesting that deep brain stimulation (DBS) may promote certain cognitive processes, we have been interested in developing DBS as a means of mitigating memory and learning impairments in Alzheimer’s disease (AD). In this study we used an animal model of AD (TgCRND8 mice) to determine the effects of high-frequency stimulation (HFS) on non-amyloidogenic α-secretase activity and DBS in short-term memory. We tested our hypothesis using hippocampal slices (in vitro studies) from TgCRND8 mice to evaluate whether HFS increases α-secretase activity (non-amyloidogenic pathway) in the CA1 region. In a second set of experiments, we performed in vivo studies to evaluate whether DBS in midline thalamic region re-establishes hippocampal dependent short-term memory in TgCRND8 mice. The results showed that application of HFS to isolated hippocampal slices significantly increased synaptic plasticity in the CA1 region and promoted a 2-fold increase of non-amyloidogenic α-secretase activity, in comparison to low frequency stimulated controls from TgCRND8 mice. In the in vivo studies, DBS treatment facilitated acquisition memory in TgCRND8 mice, in comparison to their own baseline before treatment. These results provide evidence that DBS could enhance short-term memory in a mouse model of AD by increasing synaptic transmission and α-secretase activity in the CA1 region of hippocampus.
Ocean bottom seismometer technology

Seismometers have been placed on the ocean bottom for about 45 years, beginning with the work of Ewing and Vine [1938], and their current use to measure signals from earthquakes and explosions constitutes an important research method for seismological studies. Approximately 20 research groups are active in the United Kingdom, France, West Germany, Japan, Canada, and the United States. A review of ocean bottom seismometer (OBS) instrument characteristics and OBS scientific studies may be found in Whitmarsh and Lilwall [1984]. OBS instrumentation is also important for land seismology. The recording systems that have been developed have been generally more sophisticated than those available for land use, and several modern land seismic recording systems are based on OBS recording system designs. The instrumentation developed for OBS work was the topic of a meeting held at the University of California, Santa Barbara, in July 1982. This article will discuss the state of the art of OBS Technology, some of the problems remaining to be solved, and some of the solutions proposed and implemented by OBS scientists and engineers. It is not intended as a comprehensive review of existing instrumentation.
Hepatitis Vaccination and Prophylaxis

The three most commonly identified causes of viral hepatitis in the United States are hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV). Hundreds of millions of people worldwide are infected by these viruses; many experience illness as a result. This article discusses current recommendations for vaccination and other forms of prophylaxis aimed at minimizing the clinical effects of these viruses.
Correlated Piezoelectric and Electrical Properties in Individual ZnO Nanorods

Resistivity and piezoelectric response of individual ZnO nanorods were measured using scanning force microscopy. We found a variation in resistivity of 3 orders of magnitude, from 0.1 to 155 Ωcm an...
Four Novel Mutations in the PITX2 Gene in Patients with Axenfeld-Rieger Syndrome

Mutational screening and sequence analysis of the PITX2 gene was performed in four families previously diagnosed with Rieger syndrome. The results of this analysis identified four novel mutations within the coding sequence of PITX2. These mutations were not identified in the sequence of 50 control individuals. Two mutations were found in the homeobox and would be expected to result in nonconservative amino acid changes within the second and third helixes. The remaining two mutations were found in the region downstream of the homeobox and are also predicted to result in missense mutations. In conclusion, mutations within the homeobox sequence and the adjacent coding sequence of PITX2 lead to various Rieger syndrome phenotypes characterized by a high incidence of glaucoma.
Variational Calculation of Electron Scattering by a Static Potential

The Schwinger variational method, for the approximate determination of scattering amplitude, is tested for accuracy in the case of the elastic scattering of electrons from the static potential $V(\mathrm{r})=\ensuremath{-}\frac{{e}^{2}{V}_{0}{e}^{\ensuremath{-}\ensuremath{\lambda}r}}{r}$, by using eight different forms of trial wave functions. The results are compared by checking the closeness of fit of the associated scattering amplitude with an exact solution to the problem. In the course of the calculation a number of expressions, of use in more complicated problems, were obtained and are here recorded. The parameter values used in the test were ${a}_{0}\ensuremath{\lambda}=\frac{8}{3}$, ${k}^{2}={(0.72\ensuremath{\lambda})}^{2}$, ${V}_{0}=7.8$, where ${a}_{0}$ is the first Bohr orbit radius for hydrogen.
High-throughput isolation and mapping of C. elegans mutants susceptible to pathogen infection.

We present a novel strategy that uses high-throughput methods of isolating and mapping C. elegans mutants susceptible to pathogen infection. We show that C. elegans mutants that exhibit an enhanced pathogen accumulation (epa) phenotype can be rapidly identified and isolated using a sorting system that allows automation of the analysis, sorting, and dispensing of C. elegans by measuring fluorescent bacteria inside the animals. Furthermore, we validate the use of Amplifluor® as a new single nucleotide polymorphism (SNP) mapping technique in C. elegans. We show that a set of 9 SNPs allows the linkage of C. elegans mutants to a 5–8 megabase sub-chromosomal region.
High-resolution 87Sr/86Sr chemostratigraphy of the Silurian: implications for event correlation and strontium flux

Analyses of 87Sr/86Sr in Silurian conodonts recovered from localities in North America and Europe representing 13 of the 14 defined Silurian conodont zones provide a high-resolution record of seawater chemistry for the Silurian Period. These data, which are characterized by little or no scatter, depict several high-frequency cycles superimposed on a gradual longer term rise in 87Sr/86Sr for the Silurian. High-frequency cycles have a duration of about one conodont zone, and many correlate with sequence boundaries recognized around the world. These data provide a much higher resolution image of secular changes in 87Sr/86Sr during the Silurian and may require a rethinking of models of strontium isotope flux in marine basins.
Molecular Understanding and Design of Zwitterionic Materials

Zwitterionic materials have moieties possessing cationic and anionic groups. This molecular structure leads to unique properties that can be the solutions of various application problems. A typical example is that zwitterionic carboxybetaine (CB) and sulfobetaine (SB) materials resist nonspecific protein adsorption in complex media. Considering the vast number of cationic and anionic groups in the current chemical inventory, there are many possible structural variations of zwitterionic materials. The diversified structures provide the possibility to achieve many desired properties and urge a better understanding of zwitterionic materials to provide design principles. Molecular simulations and modeling are a versatile tool to understand the structure–property relationships of materials at the molecular level. This progress report summarizes recent simulation and modeling studies addressing two fundamental questions regarding zwitterionic materials and their applications as biomaterials. First, what are the differences between zwitterionic and nonionic materials? Second, what are the differences among zwitterionic materials? This report also demonstrates a molecular design of new protein-resistant zwitterionic moieties beyond conventional CB and SB based on design principles developed from these simulation studies.