cssi/SciSciGPT-SciSciNet huggingface dataset:
First Passage in an Interval

Introduction We now develop the ideas of the previous chapter to determine basic first-passage properties for both continuum diffusion and the discrete randomwalk in a finite one-dimensional interval. This is a simple system with which we can illustrate the physical implications of first-passage processes and the basic techniques for their solution. Essentially all of the results of this chapter are well known, but they are scattered throughout the literature. Much information about the finite-interval system is contained in texts such as Cox and Miller (1965), Feller (1968), Gardiner (1985), Risken (1988), and Gillespie (1992). An important early contribution for the finite-interval system is given by Darling and Siegert (1953). Finally, some of the approaches discussed in this chapter are similar in spirit to those of Fisher (1988). For continuum diffusion, we start with the direct approach of first solving the diffusion equation and then computing first-passage properties from the time dependence of the flux leaving the system. Much of this is classical and well-known material. These same results will then be rederived more elegantly by the electrostatic analogies introduced in Chap. 1. This provides a striking illustration of the power of these analogies and sets the stage for their use in higher dimensions and in more complex geometries (Chaps. 5–7). We also derive parallel results for the discrete random walk. One reason for this redundancy is that random walks are often more familiar than diffusion because the former often arise in elementary courses. It will therefore be satisfying to see the essential unity of their first-passage properties. It is also instructive to introduce various methods for analyzing the recursion relations for the discrete randomwalk.
MTQuant: "Seeing" Beyond the Diffraction Limit in Fluorescence Images to Quantify Neuronal Microtubule Organization

Motivation: Microtubules (MTs) are polarized polymers that are critical for cell structure and axonal transport. They form a bundle in neurons, but beyond that, their organization is relatively unstudied. Results: We present MTQuant, a method for quantifying MT organization using light microscopy, which distills three parameters from MT images: the spacing of MT minus-ends, their average length, and the average number of MTs in a cross-section of the bundle. This method allows for robust and rapid in vivo analysis of MTs, rendering it more practical and more widely applicable than commonly-used electron microscopy reconstructions. MTQuant was successfully validated with three ground truth data sets and applied to over 3000 images of MTs in a C. elegans motor neuron.
Loss of Viability by Listeria monocytogenes in Commercial Calf Rennet Extract.

Loss of viability by Listeria monocytogenes (strain California) in three lots of commercial calf rennet extract was determined during storage for 56 d at 7°C. Four levels (3 × 103 to 107/ml) of L. monocytogenes were added to the rennet extract, and McBride Listeria Agar was used to determine numbers of survivors. Selected colonies thought to be L. monocytogenes were confirmed biochemically. Samples were also tested during and after completion of cold enrichment (up to 8 weeks at 4°C). Samples of rennet extract inoculated with 103 to 104 L. monocytogenes /ml were always free of viable cells of the bacterium after 28 d and sometimes after 14 d, as determined by direct plating and cold enrichment. When the inoculum was 105 to 107/ml, samples of rennet extract usually were free of viable L. monocytogenes (direct plating and cold enrichment) after 42 d and sometimes after 28 d at 7°C. In this work, results of cold enrichment correlated well with those of direct plating. All lots of rennet extract, before inoculation, were free of L. monocytogenes (direct plating and cold enrichment).
E2f-2 Regulates Caspase-3 Expression and Mitotic Checkpoint Control during End-Stage Erythroid Maturation.

E2f-2 is a member of the E2F superfamily of transcription factors that plays multiple roles in regulating cell cycle progression, cell cycle exit and checkpoint control [1]. While over-expression studies have ascribed a role for E2f-2 as a transcriptional activator of cell cycle genes, our loss of function studies performed in vivo have revealed a novel role for E2f-2 in repressing cellular proliferation and mediating differentiation. Our expression analyses demonstrate that E2f-2 is up-regulated in hematopoietic tissues, and is most strongly expressed in differentiating erythroblasts. Furthermore, E2f-2 is the major pRb-associated E2F in hematopoietic tissues, suggesting E2f-2 can function as a co-repressor of cell cycle genes during end-stage differentiation. Compound Rb−/−;E2f2−/− mice were generated to understand how deregulated E2f-2 activity contributes to the erythroid defects in Rb null mice. Loss of E2f-2 restored end-stage erythroid differentiation and enucleation to Rb null erythroblasts and extended survival of Rb null mice. Loss of E2f-2 was sufficient to bypass the mitotic arrest observed in Rb null erythroblasts [2] and was associated with reduced expression of known E2f target genes involved in M phase checkpoint control, such as Aurora B and Survivin. In addition, we observed a significant increase in caspase-3 expression in E2f-2 null erythroblasts and demonstrate, for the first time, direct regulation of caspase-3 expression by E2f-2. Given known roles for caspases in promoting erythroid differentiation and enucleation, we have over-expressed caspase-3 in Rb null erythroblasts and are currently analyzing its effects on cell cycle and maturation. Thus, our work identifies caspase-3 as a key downstream target of E2f-2 during end-stage erythroid differentiation whose expression may alleviate enucleation and mitotic defects in Rb null erythroblasts. Future work aims to understand which E2f-2 target genes ensure mitotic checkpoint control, and the molecular mechanism by which caspase-3 coordinates cell cycle control with erythroid differentiation.
Tableside Justice: Racial Differences in Retributive Reactions to Dissatisfaction

Existing evidence indicates that racial discrimination is a common, if not pervasive, feature of Black Americans’ experiences in U.S. consumer markets. However, few studies have quantitatively expl...
A Computer Based Data File Management System for Telemetry Studies on Free Ranging Animals

Telemetry studies on free ranging animals quickly generate large quantities of location data which are often difficult to analyze. A computer based data file management system, based on a modification of the Statistical Package for the Social Sciences, was developed for acquisition, update and analyses of such data. Field data are recorded directly on a miniature remote data terminal, eliminating need for field data forms and verification. Location coordinates are subsequently plotted by a computer program interfaced with the Tectronix remote terminal. Time elapsed from data acquisition to update and/or analyses is less than 24 h.
Clinical Disparities between Primary Versus Secondary MGUS in Veteran Patients.

Background: Monoclonal gammopathy of unknown significance (MGUS) is characterized by low levels of a monoclonal protein (M protein) in the serum or urine that is produced by a single clone of plasma cells. Though published evidence indicates that the incidence of MGUS increases with age, the clinical differences between young versus older MGUS patients are not completely understood. We investigated the age-dependent clinical characteristics of veteran patients with MGUS. Objective: To identify age-dependent disparities in the clinical characteristics of veteran patients with primary versus secondary MGUS. Methods: A retrospective chart review of 327 MGUS patients seen at the Kansas City Veteran Affairs Medical Center over the last 20 years was performed. “Primary” MGUS was defined as presence of monoclonal immunoglobulin protein (M-spike) in the absence of multiple myeloma (MM), primary amyloidosis, or leukemia/lymphoma. In this report, we use the term “Secondary” MGUS when an M-spike is associated with HIV, or non-HIV-infections, and/or autoimmune diseases. In the final analysis, we broadly subdivided patient with MGUS into age-group ≤ 55 years and ≥ 55 years. Results: Of the total 327 patients, 14% (44/327) belonged to the age group ≤ 55 years. In our analysis, “Secondary” MGUS was more prevalent in patients ≤ 55 years (30/44; 68%) as compared to that in the ≥ 55 years age group (25/283; 8.5%; p-value p-value Conclusion: MGUS in young patients (age ≤ 55 years) is often found in conditions associated with chronic antigenic stimulation or immunosuppression, such as chronic hepatitis B or C, HIV infections, and autoimmune diseases. We thus recommend that young patients (age ≤ 55 years) with MGUS undergo testing for hepatitis B/C, HIV infection if there is a possible history of exposure to these viruses. Our analysis also suggests that these so-called “secondary” MGUS are benign disorders.
A command-level study of Linux kernel bugs

As computer systems increase in size and complexity, bugs become ever subtler and more difficult to detect and diagnose. A bug could exist at different layers of computer systems (e.g., applications, shared libraries, file systems, device firmware), or could be caused by the incompatibility among layers. In many cases, bugs would require a very specific combination of events to be triggered and are difficult to replicate, making detection and diagnosis more complicated. Most existing tools for debugging focus on a single layer of the systems (e.g., applications), which are intrusive to the target layer and are fundamentally limited for analyzing issues involving multiple layers. As the first step towards building a multi-layer diagnostic framework, this paper presents our efforts to study the behaviors of Linux kernel bugs at the host-device interface. More specifically, we designed workloads to trigger known kernel bugs, recorded the SCSI commands observed under different kernels, and analyzed the impact of kernel bug patches after multiple runs of the workloads by counting the occurrence of individual SCSI commands. Our preliminary results show that it is possible to identify potential synchronization bugs in the kernel from information at the host-device interface level.
Measurement of UV Emission from a Diffusing Optical Fiber Using Radiochromic Film.

Analysis of the emission pattern from optical diffuser tips is vital to their usage in biomedical applications, especially as they find growing functionality beyond established phototherapy techniques. The use of ultraviolet radiation with diffuser tips increases the need to accurately characterize these devices, both for effective application and to avoid potentially dangerous exposure conditions. This work presents a new method to capture the diffusion pattern at a high resolution through the use of radiochromic film. The film is positioned in a cylinder around the diffuser, light is emitted from the diffuser onto the film, and the film expresses a color change relative to the exposure amount. The resulting emission map shows the distribution of power from the diffuser in all direction. This method, which is both quick and inexpensive, generates high resolution data much simpler than previously published works which required precise goniometric positioning. This article is protected by copyright. All rights reserved.
Purification and Properties of Cytochrome C-553 from the Green Sulfur Bacterium Chlorobium Tepidum

The green sulfur photosynthetic bacteria have a reaction center that is similar in some ways to photosystem 1. The oxidized donor P840 is reduced by a membrane-bound cytochrome c which may accept electrons from external reducing agents such as sulfide and thiosulfate, through a series of water-soluble c-type cytochromes.
Are Women More Ethical Lawyers? An Empirical Study

This is a statistical study of all publicly-reported attorney disciplinary actions decided in the United States in calendar year 2000, about 3500 cases. The study concludes that female attorneys are, in fact, disciplined at a significantly lower rate than male attorneys, relative to their respective proportions in the United States attorney population, and incur less severe sanctions than their male counterparts. For example, although male and female attorneys comprised 76.4% and 23.6% of all licensed attorneys in the United States, 88.3% of the disciplined attorneys were male and 11.7% were female. The article examines the overall rates of discipline imposed, the frequency with which different types of sanctions (such as disbarment and suspension) were imposed, the frequency with which male and female attorneys committed different types of ethical violations (such as incompetence or failure to communicate with clients), and other potentially relevant differences. Regression analyses modeled from the available data suggest that gender is not a significant predictor of the length of term suspensions. The article concludes with a discussion of possible factors contributing to the gender differences that were found in the study, with attention to other empirical studies of gender and moral reasoning.
The chain reaction of the blood clotting mechanism in relation to the theory of hemostasis and thrombosis.

Detailed evidence has been accumulating that at least one chain reaction occurs during the coagulation of blood. Both the metamorphosis of platelets and the development of thrombokinase appear to be involved. The autocatalytic effect may serve a function in making possible the growth of a hemostatic plug. It also offers advantages in the physiologic control of the clotting mechanism. It is likely that the chain reaction occurs in most instances where a thrombus forms, and plays some part in its propagation. The chain reaction is a potentially explosive phenomenon which demands an adequate countermechanism. With materials derived from blood, reactions have long since been demonstrated which can reduce thrombokinase activity, inactivate thrombin and liquefy fibrin. These reactions may help to maintain the fluidity of the circulating blood by removing the products of smoldering clotting reactions. Such effects could help to delimit the growth of a hemostatic plug, or to end the propagation of a thrombus. While it is now possible to correlate in this way the data on blood coagulation with present knowledge of hemostasis and thrombosis, critical gaps in our understanding still remain.
Author Meets Her Critics: Black Feminist Politics from Kennedy to Obama – Duchess Harris

DescriptionThis panel is designed to bring an author of a recent book deemed to be important contributions to Black Women’s Studies together with discussants chosen to provide different viewpoints. Duchess Harris’ 2009, 2011 book, Black Feminist Politics From Kennedy to Obama (published by Palgrave Macmillan), has been selected discussion.Taking an interdisciplinary approach, this book analyzes Black women’s involvement in American political life, focusing on what they did to gain political power between 1986 and the present, and why, in many cases, they did not succeed. Duchess Harris demonstrates that Black women have tried to gain centrality through their participation in Presidential Commissions, Black feminist organizations, theatrical productions, film adaptations of literature, beauty pageants, electoral politics, and Presidential appointments. She contends that “success” in this area means that the feminist identified Black women in the Congressional Black Caucus who voted against Clarence Thomas’s appointment would have spoken on half of Anita Hill; Senator Carol Moseley Braun would have won re-election; and Shirley Sherrod wouldn’t have been forced to resign from her USDA position. Harris contends that if this truly a post-racial America, there should be no obstacles to discussing issues concerning racism at the national level.ParticipantsOur roundtable confirmed participant and invited participants are expert observers of Black women’s politics. We anticipate a lively discussion, informed equally by empirical analysis and by panelists’ lived experiences as politically engaged and civic minded Black women. We expect spirited participation by the audience, and will set aside ample time for open discussion.
Psychopathology and the Polyglot

The polyglot—the person who possesses linguistic competence in more than one language—presents a fascinating series of challenges and problems for both the psycholinguist and the clinical psychologist. When two or more linguistic codes are available, what factors determine the selection of one over the other in the encoding of psychopathological experiences? In terms of the Sapir-Whorf (linguistic relativity) hypothesis, does the possession of more than a single language code imply the possession of more than one Weltanschauung? Are delusional and hallucinatory formations susceptible to influences from competing linguistic systems within the bilingual individual? Does bilingualism contribute in any significant way to emotional instability? These and many more intriguing questions are raised by the phenomenon of multilingualism vis-a-vis psychopathology.
Approximation by circles

The problem considered is to assign a measure of circularity to a given compact set in the plane. The measure adopted is the size of the smallest annulus containing the given set. Two different notions of the size of an annulus, that of area and that of difference of radii are studied.
Predicting Information Spreading in Twitter

We present a new methodology for predicting the spread of information in a social network. We focus on the Twitter network, where information is in the form of 140 character messages called tweets, and information is spread by users forwarding tweets, a practice known as retweeting. Using data of who and what was retweeted, we train a probabilistic collaborative filter model to predict future retweets. We find that the most important features for prediction are the identity of the source of the tweet and retweeter. Our methodology is quite flexible and be used as a basis for other prediction models in social networks.
Phototriggered Depolymerization of Flexible Poly(phthalaldehyde) Substrates by Integrated Organic Light-Emitting Diodes.

We demonstrate phototriggered depolymerization of a low ceiling temperature (Tc) polymer, poly(phthalaldehyde) (PPHA), via internal light emission from integrated organic light-emitting diodes (OLEDs) fabricated directly on flexible PPHA substrates with silver nanowire electrodes. The depolymerization of the PPHA substrates is triggered by absorption of the OLED emission by a sensitizer that activates a photoacid generator via energetically favorable electron transfer. We confirm with Fourier-transform infrared spectroscopy that the photon doses delivered by the integrated OLED are sufficient to depolymerize the PPHA substrates. We determine this critical dosage by measuring the operating lifetimes of the OLEDs whose failure is believed to be due to significant mechanical softening during the liquefaction of decomposed phthalaldehyde monomers.
Assessing Quality of Pharmacist-Led Education for Patients with COPD Using the Lung Information Needs Questionnaire: A Pilot Study.

Background: Transitioning a patient from the hospital to home is an area of vulnerability for patients with Chronic Obstructive Pulmonary Disease (COPD). Patients with COPD frequently readmit as they often do not understand their disease state, medications or when to seek medical attention. Objectives: The objective of this study is to determine the impact that pharmacist-led education has on a patient’s understanding of their disease state by assessing the results of the Lung Information Needs Questionnaire (LINQ). Methods: This study uses a quasi-experimental design to formally assess pharmacist-led education provided to patients with COPD using the LINQ. The LINQ was used to assess knowledge of the disease state and medications before and after receiving education on disease state management, smoking cessation and proper medication use. Results: A total of 17 patients completed the LINQ. The survey results showed a statistically significant improvement in patient understanding in 4 of the 6 targeted areas. Conclusion: Results from the formal assessment using the LINQ suggest that pharmacist-lead education for COPD patients is beneficial and reliable. This study presents a continued need for patient education and research in this high-risk patient population. Article Type: Original Research
Increased Plant Growth with Hematite Nanoparticle Fertilizer Drop and Determining Nanoparticle Uptake in Plants Using Multimodal Approach

There is an emerging scientific interest in the use of nanoparticle fertilizers for enhanced agricultural and bioenergy crop production to meet the growing food and energy demands of the world. The objective of designing the nanoparticle fertilizers is to effectively deliver the required nutrients for the plants without adding large quantities of fertilizer to the environment. However, most reports on nanoparticle fertilizers so far, involved the addition of nanoparticles to the hydroponic system or the soil. In this study, we report a new modified seed presoak strategy using a drop of Fe-enriching hematite nanoparticle dispersion to enhance plant growth and production in four different legume species, i.e., chickpea, green gram, black bean, and red bean. The hematite nanoparticle fertilizer drop promoted a 230-830% increase in plant growth with green gram showing the highest increase, based on our prolonged and statistically reliable growth studies. In general, we observed an increase in the survival span of plants, a twofold increase in fruit production per plant, nearly two times faster fruit production, and healthy second-generation plants with the nanoparticle treatment; however, there were slight species-specific variations. We used a novel multimodal material characterization approach combining three techniques, hyperspectral imaging, Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma optical emission spectroscopy (ICP-OES), to evaluate the internalization and transport of the nanoparticle fertilizer within the plants. Our results indicated that the hematite nanoparticles were transported through the roots and stems and were localized in the leaves after 10 days of growth in pots of soil. Therefore, the modified seed presoaking method using a drop of hematite nanoparticle will be highly attractive in enhancing plant growth and health, while minimizing environmental impacts.
Off‐label use of prescription analgesics among hospitalized children in the United States

PURPOSE Analgesics are the most frequently administered medications among hospitalized children. However, current analgesic prescribing patterns have not been well defined among hospitalized children. In addition, it is unknown what proportion of prescription analgesics is approved for use in children and what proportion is used "off-label." METHODS Nationally representative data from 52 tertiary care children's hospitals in the Pediatric Health Information System were queried to determine prescribing rates of analgesic medications. We analyzed hospitalizations for children <18 years occurring between 1 April 2010 and 30 June 2018. Food and Drug Administration (FDA) drug labels were reviewed for pediatric information, and prescriptions were classified as on- or off-label based on age, route, and formulation. RESULTS Among 4.9 million hospitalizations, 1.8 million (37.6%, 95% confidence interval [CI] = 37.6-37.7) were associated with use of a prescription analgesic. Overall, 36.7% (95% CI = 36.7-36.7) of hospitalizations included off-label analgesic therapy, with 26.4% (95% CI = 26.4-26.5) associated with two or more off-label analgesics. Off-label analgesic use was higher among hospitalizations in the intensive care unit (61.5%) or with an operating room procedure (92.8%). Rates of off-label prescribing increased with age, peaking at 50.5% for adolescents. Prescription analgesics administered most frequently were morphine, fentanyl, and ketorolac, with off-label use occurring in 24.5%, 23.1%, and 11.3% of hospitalizations, respectively. CONCLUSIONS Over a third of pediatric hospitalizations were associated with the administration of prescription analgesics that have not been labeled for use in children. Our findings highlight the critical need to ensure that safe and effective analgesics are developed for children and that pediatric labeling is expanded for existing analgesics to inform treatment decisions.
Experience is not Required: Designing a Sailing Experience for Individuals with Tetraplegia

Sailing has a range of positive impacts on mental and physical health-related quality of life for individuals with tetraplegia. This work describes the iterative design process of creating an adaptive sailing experience that requires minimal training and preparation for individuals with tetraplegia. The Tetra-Sail is an adaptive sailing experience that uses a Shared-Control approach to accept input from both the main user and an experienced adaptive instructor (control partner). This approach was used to create a usable experience for individuals with all types of physical abilities, including participants with high-level and complete spinal cord injuries characterized by loss of sensation and function below their site of injury, with minimal preliminary training. A study of nine participants (five first-time users of Tetra-Sail and four who had used previous iterations) suggested that participants found Tetra-Sail usable and enjoyable. Participants expressed feelings of empowerment, which they attributed to the flexible adaptation to their abilities supported by the implementation of Shared-Control.
刻板印象与男性气质：性别视角下的男护士 (Stereotype and Masculinity: A Gender Perspective to Review the Male Nurse)

Chinese Abstract: 随着社会和护理行业的发展，男护士逐渐活跃在这个曾经被视作只有女性才会从事的行业之中。本文从社会学和性别研究的理论视角出发，在对两家医院两个月的参与式观察与26位相关人士的深度访谈后，通过对与男护士相关的最明显的一优一缺点——“力气大”与“不细心”进行了细致的梳理与批判，对目前男护士的学术研究和现实管理中存在的过分偏重于生物性别解释与性别本质主义的问题进行了再讨论。本文发现，这种基于生物性别的刻板印象似的优缺点虽然突出了男护士在特殊科室的重要作用，但无益于其护士身份自我认同的稳固和发展，亦使得其陷入了更深的自我与外界规训之中，并对改善护理质量的要求可能会产生一定的误导。本文也会以男护士为主体，分析他们是如何通过对信息的裁剪和展演对自我身份与其男性气质进行重新的建构与展示的。 English Abstract: With the development of the society and the nursing profession, male nurses are gradually becoming active in the profession that was once considered to be only women. From the theoretical perspective of sociology and gender studies, this paper, after two months of participatory observations of two hospitals and in-depth interviews with 26 relevant individuals, thoroughly examine the most stereotypical advantages and disadvantages associated with male nurses - The "great strength" and "not careful enough." This paper finds that the advantages and disadvantages of this kind of gender-based stereotypes highlight the important role of male nurses in special departments, but they are not conducive to the stability and development of their identity as a nurse, which also makes them fall into a deeper self-doubt and discipline. This article also examines how male nurses reconstruct and display their identity and masculinity through the strategically display/hide information.
Lessons From Research for Implementing An Instructional Accommodations Model in Secondary Inclusion

Inclusion teachers at the secondary level need research-based guidance on how to support students with disabilities using accommodations in the classroom. A team of general education and special education teachers developed a model for planning, implementing, and monitoring instructional accommodations. The model calls for students’ active engagement. Findings from two studies on students with high incidence disabilities learning a strategy for “self-accommodating” inform on how general educators and special educators can implement the Secondary Classroom Accommodations Model with active student involvement. Subscribe to LDMJ
TH‐CD‐207‐01: BEST IN PHYSICS (IMAGING): Correction of the First‐Pass Distortion in Arterial Input Function of DCE MRI for Perfusion Quantification

Purpose: To quantify perfusion in an abdominal organ (liver, spleen or kidney) from dynamic contrast-enhanced (DCE) MRI, an arterial input function(AIF) is commonly sampled in a volume of interest (VOI) on the descending aorta. However, the peak of the first pass of the AIF could be corrupted, due to the T2* effect of high contrast-concentration, particularly at 3T MR, and other factors. This study aimed to correct this distortion in the AIF for DCE MRI perfusion quantification of an abdominal organ. Methods: A post-processing correction method was developed to automatically recognize the distortion portion in the first pass of an AIF and fit it with a gamma-variate function. The fitting of the first pass was incorporated in pharmacokinetic(PK) modeling of the DCE curves from VOIs in both spleen and kidney. The optimal solution was determined by balancing between best fitting the PK model and matching the fitted first pass with the measured one. The corrected AIFs were applied to quantify hepatic perfusion from DCE MRI of 6 patients, which were acquired on a 3T scanner using a VIBE sequence. Results: In the DCE-MRI of 6 patients, the original AIFs had 20%±6% saturation in the first-pass peak compared with the corrected AIFs. Using the corrected AIFs to quantify hepatic perfusion yielded average differences of-36% (p=0.002) and 17% (p=0.01) in respective arterial perfusion and portal venous perfusion on VOIs of normal hepatic tissue, compared to those estimated using the original uncorrected AIFs. Conclusion: The proposed method corrects the distortion in the first pass of the AIF sampled in the aorta, and could improve DCE-MRI perfusion quantification in the liver and other abdominal organs. The resultant perfusion may assess tissue function and tumor response to radiation and provide tools to support physiologically adaptive RT. The work is supported in part by RO1CA132834 and PO1CA59827 The work is supported in part by NIH RO1CA132834 and PO1CA59827
Na/K Pumps and Passive K+ Transport in Large and Small Reticulocytes of Anemic Low- and High-Potassium Sheep

Publisher Summary This chapter discusses the membrane transport events accompanying the cellular maturation of erythrocyte precursors into enucleate high potassium (HK) as well as low potassium (LK) red cells. This study is of interest because of its general aspect of the relationship between active and passive cation transport systems during cellular differentiation and maturation. The basic strategy of the study is to isolate cells by centrifugal elutriation and characterize by flow cytophotometry the reticulocyte population newly produced in response to massive bleeding. Then eluate is measured in the separated cells active K+ pump and passive K+ leak fluxes, the number of ouabain binding is also measured, this leads to pump sites per cell. In the course of the response of both HK and LK sheep to massive hemorrhage, the simultaneous appearance in the peripheral blood of two distinct reticulocyte populations was detected cyto­photometrically. As a result, a large macrocytic population (population M cells) and a small population with rather normocytic reticulocytes whose cell volume was indistinguishable from that of the older LK red cells.
Controller design and evaluation for vehicle run-off-the-road and recovery

Run-off-the-road (ROR) and unsuccessful recovery events account for a significant percentage of fatal vehicle crashes. Changes to roadway infrastructure have reduced the severity of automotive crashes; however, it is driver performance which remains a primary contributing factor to these incidents. An on-board vehicle control system, using combined steering and differential braking, provides enhanced safety by removing driver error from the recovery process once the ROR event has been identified. In this study, two control algorithms, based on sliding mode and state flow theories, have been designed to automatically recover a vehicle from this dangerous scenario. A driver model was also developed based on experimental data gathered at a tire manufacturer's test track. The controllers were numerically evaluated for a common road departure and return situation with comparison to the empirical driver model. The results show that both controllers safely recovered the vehicle and outperformed the driver steering model. Specifically, the state flow controller reduced recovery time by 40% compared to the sliding mode controller, while the driver model resulted in vehicle spin out.
Wildfire Outreach and Citizen Entrepreneurs in the Wildland–Urban Interface: A Cross-Case Analysis in Colorado

Due to rapid growth in the wildland-urban interface (WUI), the risk to lives and property from wildfires is increasing in the western United States. While previous studies have identified factors that influence residents’ perceptions of wildfire risk and responsibility for mitigation, less research has been conducted on how mitigation information is disseminated to residents or the most effective strategies for doing so. During an examination of two case studies of catastrophic wildfires in Colorado, an important actor involved in wildfire outreach emerged that we label the citizen entrepreneur. Citizen entrepreneurs are highly motivated community members who can help resource-constrained wildfire agencies encourage mitigation on private property by directly engaging with WUI residents. Using data from interviews with wildfire professionals and focus groups with residents, this research note introduces the concept of citizen entrepreneurs and provides an initial examination of the important role they can ...
Myopathy in Status Asthmaticus: Relation to Neuromuscular Blockade and Corticosteroid Administration

Myopathy is a rare complication that arises during management of status asthmaticus that may be related to administration of corticosteroids and neuromuscular blocking agents. We present 4 patients with myopathy and a review of the 31 previously reported patients in the literature. All patients received corticosteroids, and 33 of the 35 patients received neuromuscular blocking agents. Muscle weakness was often diffuse and, in several patients, involved the muscles of respiration. Creatine kinase values ranged from normal to markedly elevated. Diagnosis was obtained by electromyogram and muscle biopsy in most patients. Resolution of the muscle weakness occurred over a period of days to months. Patients in whom myopathy developed required mechanical ventilation for longer periods than patients intubated for status asthmaticus without myopathy.
Minority students, affirmative action, and the admission process: a literature review, 1987-1998.

Background: Despite numerous initiatives, medical educators have failed to effect a sustainable increase in the number of underrepresented minority students at medical colleges in the United States. This study reviewed the recent literature regarding the admission process to specifically examine and determine if current policies are helping facilitate the proper representation of minority students. Papers were selected on the basis of their relevance to the topic of underrepresented minority students and medical school admission policies and were limited to the years between 1987 and 1998. Each paper was individually evaluated on the basis of its study design and soundness of its contribution to the field. Summary: The articles are organized under 4 major themes: Cognitive factors (mostly Medical College Admission Test scores and grade point average), noncognitive factors (e.g., leadership ability, interpersonal skills, motivation), the admission interview, and enrichment programs. Table 1 briefly summari...
A study of the oxidation of tantalum nitride by ellipsometry and auger electron spectroscopy

Abstract Ellipsometry and Auger electron spectroscopy in conjunction with in-situ ion sputtering have been used to study the thermal and anodic oxidation of thin tantalum nitride (Ta2N) resistor films which are used in microelectronic circuits. In addition, the effects of thermal oxidation on the resistor-conductor contact resistance and conductor adhesion have been investigated. Thermal oxide thickness and stoichometry were estimated by Auger electron spectroscopy. A more accurate determination of oxide thickness was obtained by using multiple angle-of incidence ellipsometry. The thermal oxide was found to demonstrate a parabolic growth rate, in agreement with other workers. It was determined that the contact resistance should not be adversely affected by oxidation of the tantalum nitride at room temperature for storage times of several months; no significant decrease in the conductor adhesion was observed for oxide thicknesses up to 8 nm. A significant difference in the stoichiometry and refractive index of the thermally and anodically oxidized films was found, however. Depletion of the nitrogen from the surface of the anodically oxidized Ta2N films resulted in an increase in the refractive index of the anodic oxide layer to a value close to that of pure Ta2O5.
Structural characterization of colonic cell types and correlation with specific functions.

In conclusion, the adult colon is lined by at least eight distinct epithelial cell types, each of which has one or more important functions. Collectively, they constitute a structural and functional barrier protecting the internal milieu from direct contact with luminal components such as the indigenous bacterial flora or exogenously introduced antigens or viruses. Furthermore, each cell type performs one or more functions related to osmoregulation, mucin synthesis and release, cell renewal, hormonal regulation of absorption/secretion, motility, and blood supply, plus a variety of immune functions. There are, nonetheless still cells types with unknown function(s), and it is likely that additional function(s) for the existing cells will be defined. It is likely, too, that further regional differences in cell types and/or functions will be elucidated.
Assessing and Facilitating Milk Transfer During Breastfeeding for the Premature Infant

Abstract Premature infants often experience problems when direct at-breastfeeding is initiated. More specifically, these difficulties include an inability to maintain attachment to the maternal nipple and/or falling asleep soon after attaching to the breast. Although studies show that premature infants are more physiologically stable during breastfeeding compared to bottle feeding for these initial feedings, milk transfer rates are generally lower at the breast. When clinicians have a better understanding of maternal and infant factors contributing to milk transfer during breastfeeding, interventions conducive to improving outcomes can be developed. This article seeks to describe the concept of milk transfer and the factors contributing to milk intake during breastfeeding for the premature infant.
Reflections on becoming a specialty and its impact on global emergency medical care: Our challenge for the future

International emergency medicine development includes many activities. Among them are efforts to establish and support the development of the specialty of emergency medicine. In carrying out such activities, it is important for emergency physicians to be aware of the story of the establishment and development of the specialty of emergency medicine in the United States and to seek ways to support similar efforts in other countries. The benefits of specialty development toward improving emergency care globally are likely to be immense.
Characterization of a Novel Baboon Virus Closely Resembling Human T-Cell Leukemia Virus

Abstract We report the isolation of a virus from a baboon imported from Kenya and the analysis of the nucleotide sequence of the env gene. Comparison of the complete nucleotide sequence of the env gene of different HTLV-1 strains and the baboon T-cell leukemia virus (designated BTLV) indicated similarities ranging from 92.5 to 97.4%. In contrast, only 89.1% similarity was observed between the BTLV env sequence and that of simian T-cell leukemia virus (PtM3). The sequences corresponding to the glycosylation sites, endoproteolytic processing site, and major immunological determinants were strictly conserved between BTLV and HTLV-1. To characterize the expressed protein we used a vaccinia expression system, which indicated that a protein of 62 kDa is encoded by the envelope gene. The protein acquired mostly high mannose modifications and was localized predominantly in the endoplasmic reticulum. A fraction of the protein was expressed at the cell surface, where it could induce membrane fusion of target cells. The existence of HTLV-1-like viruses in baboons indicates the potential risk of transmission of such virus from these nonhuman primates to humans, thus highlighting the need for specific screening for such viruses during xenotransplantation.
Reactive Intermediates from DMDO Oxidation of Ynamides. Trapping of a de novo Chiral Push−Pull Carbene via Cyclopropanation

The reaction profile of DMDO oxidations of ynamides is described. This work illustrates the first examples of highly diastereoselective intramolecular cyclopropanations of a push−pull carbene derived from alkyne oxidation. In addition, the ynamide oxidation provides facile access to ketoimides and reveals mechanistic insights into the chemistry of electronically biased oxirenes.
The effects of microcomputer‐based laboratory exercises on the acquisition of line graph construction and interpretation skills by high school biology students

Effects of microcomputer-based laboratories and level of cognitive development on tenth-grade biology students' ability to construct and interpret line graphs was investigated. Fortysix students enrolled in general biology classes at a rural high school volunteered to participate in the study. These students were administered instruments to assess level of cognitive development and line-graphing ability. Ten students that scored between zero and three and ten students that scored between six and ten on the graphing assessment were chosen to participate in the study. The 20 students were then assigned to either experimental or conventional groups to achieve a matched design with relation to gender and line-graphing ability. Statistical analysis of the data indicated no effect due to instructional method on graph-interpretation abilities. An instructional effect was demonstrated for graph-construction tasks (p < 0.10) with the conventional group outperforming the microcomputer-based laboratory group. Effect sizes of −1.01 and 0.48 were found for graph-construction and -interpretation skills, respectively. Effects related to cognitive development were indicated with those students classified as high cognitive development outscoring those classified as low (p < 0.10) This was true for both graph-construction and graph-interpretation tasks. No two-way interactions were found.
Chemical modifications of transfer RNA species. Metal ion binding to monoperphthalate-treated tRNA

Abstract Oxidation of the “exposed” adenosine moieties in intact tRNA's enhances the binding of heavy metal ions to the tRNA's. Experiments utilizing copper, cadmium and samarium ions indicated that binding enhancement was directly proportional to the degree of oxidation.
Effects of catalyst material and atomic layer deposited TiO2 oxide thickness on the water oxidation performance of metal–insulator–silicon anodes

We report on the effects on water oxidation performance of varying (1) the nanoscale TiO2 thickness and (2) the catalyst material in catalyst/TiO2/SiO2/Si anodes. Uniform films of atomic layer deposited TiO2 are prepared in the thickness range ∼1–12 nm on degenerately-doped p+-Si, yielding water oxidation overpotentials at 1 mA cm−2 of 300 mV to 600 mV in aqueous solution (pH 0 to 14). Electron/hole transport through Schottky tunnel junction structures of varying TiO2 thickness was studied using the reversible redox couple ferri/ferrocyanide. The dependence of the water oxidation overpotential on ALD-TiO2 thickness, with all other anode design features unchanged, exhibits a linear trend corresponding to ∼21 mV of added overpotential at 1 mA cm−2 per nanometer of TiO2 for TiO2 thicknesses greater than ∼2 nm. For thinner TiO2 layers, an approximately thickness-independent overpotential is observed. The linear behavior for anodes with thicker TiO2 layers is consistent with the predicted effect of bulk TiO2-limited electronic conduction on the voltage required to sustain the current density across the TiO2/SiO2 insulator stack. Eight different oxygen evolution catalysts of thickness 1–3 nm are studied. For the anodes investigated, 3 nm of Ir or Ru gave the best water oxidation performance, but both thinner layers and other catalysts can be quite effective, suggesting the potential for reduced materials cost. Lastly, a flat band voltage analysis of solid state thin film capacitors was done for five different gate metals on n-Si to probe junction energetics directly relevant to a photoanode. The results are consistent with a Schottky junction in which the Fermi level at the semiconductor surface is unpinned.
Building the 3-D Integral DMO Operator In the Slant-stack Domain

We propose a 3-D integral dip-moveout (DMO) approach based on constructing the DMO operator in the slant-stack domain. The kinematics of the operator is first computed in the ray parameter domain and described as three parametric functions for the zero-offset trace location x0-, y0-, and zero-offset traveltime t0. 3-D slant-stack transform is used to merge the three functions into one that defines the same operator in the slant-stack domain. Each input sample is smeared as a sinc function onto the output panel in the slant-stack domain, along the DMO operator trajectory. Then, an accurate and efficient inverse 3-D slant-stack transform reconstructs the data in the conventional timespace domain. Two significant advantages arise from this implementation. First, it can kinematically and dynamically handle triplications associated with v(z) media; second, this integral implementation has no constraint on the sampling or geometry of the input data.
Enzyme kinetics: Inhibition equations derived from the inelastic collision hypothesis

The inelastic collision hypothesis of enzyme action has been proposed by G. Medwedew. This theory has been here extended to the cases of competitive and non-competitive inhibitors, which form enzyme-inhibitor complexes, and to the cases of competitive and non-competitive substrates. The resulting equations are discussed and contrasted to those derived from the classical enzyme-substrate hypothesis. The original formulation of Medwedew neglects the presence of the enzyme-substrate complex although the general theory admits the formation of this complex. The formulation has been revised and extended to include complex formation. The resulting equation is discussed in terms of the usual criteria used to evaluate the Michaelis-Menten-Briggs-Haldane equation.
An initial measurement of photosynthetic productivity in Lake Tanganyika

Measurements of 14C uptake and oxygen evolution by phytoplankton in Lake Tanganyika provide the first direct estimates of the lake's primary productivity. These measurements at the expected nadir of the annual range suggest that Lake Tanganyika is as productive as other large, deep tropical lakes.