cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrating a Digital Textbook into a Statics Course

This innovative practice work-in-progress paper presents the findings of the first implementation of a digital textbook developed by the authors. Recognizing that technology offers new ways to conceive of what a textbook is and does, the digital statics textbook is designed to be a personalized learning experience for students. It includes numerous innovations to provide real-world context and motivation for the theory, scaffold learning, support students in developing systematic and structured problem solving processes, and provide immediate feedback. The online materials were integrated into a lecture- and lab-based, active-learning course offered for approximately 80 students in a 10-week quarter. The online resources were accessible to the students through the university’s learning management system. While students learned the material and performed well, they were challenged by this new method of accessing a textbook and identified several limitations of the integration of the digital resource in the course. Instructors need to determine the right mix of online problem solving with immediate feedback and paper-based homework that reinforces a structured problem solving approach. A second offering was underway at the time of writing this paper.
Rigid segmental cervical spine instrumentation is safe and efficacious in younger children.

The utilization of cervical spine instrumentation in the young pediatric patient is not well reported. This study presents outcomes and complications of cervical spine instrumentation in patients who underwent cervical spine fusion surgery before age 10. Radiographic and clinical data were collected on all patients who underwent cervical spine surgery with instrumentation at a single institution between January 1, 2006, and March 31, 2015. Patients were ≤ 10 years of age at the time of surgery with any cervical spine deformity/injury diagnosis. Patient demographics, details on cervical spine diagnosis, procedural data, imaging data, and postoperative follow-up data were collected. Twenty children met the criteria and were included in the study with a mean follow-up of 10.6 months (3 months–2 years). Initial indication for cervical spine correction surgery included deformity (7 cases), trauma (6 cases), instability (3 cases), stenosis (2 cases), rotary subluxation (1 case), and infection (1 case). Fifteen cases were treated with adult 3.5-mm cervical spine instrumentation, 3 with wiring (1 sublaminar and 2 spinous process), and 2 with cannulated screws. Postoperative immobilization included 16 halo fixation, 3 collars, and 1 CTO. Overall, there were five complications related to the surgery. Two patients who had wiring (1 sublaminar and 1 spinous process) developed a non-union and required revision surgery (1 with cannulated screws and 1 with 3.5-mm segmental cervical spine instrumentation). One patient developed a postoperative infection that required incision and drainage. Five patients developed superficial pin infections for their halo. Two deformity patients experienced neurological complications that were likely unrelated to the cervical instrumentation. Rigid segmental fixation can be safe and efficacious when used in pediatric cervical spine patients. Whether used with halo or orthosis, patients experience minimal to no complications from the instrumentation and achieve successful fusion. Cervical spine wiring had a high risk of non-union requiring revision surgery. The incidence of wound infection was low with one in 20 cases.
Intervention, aid, and institution-building in Iraq and Afghanistan: A review and critique of comparative lessons

Since 2001 international attention has focused on the conflicts in Iraq and Afghanistan, and specifically on the question of whether external intervention can assist weak or fragile states in successfully making the transition to stable democracies. Despite their differences, Iraq and Afghanistan are often considered together in analyses of state-building, and multiple observers have explored the lessons of one for the other. Yet Iraq and Afghanistan are not the first cases of US military intervention and occupation for the purposes of transforming a foreign regime. This paper provides a review and critique of the literature on why some of these interventions were more successful than others in building robust and effective state institutions.
Authenticating Resolutions of Agency Authority in Large Transactions: Justifying Doubt Suppression

When a large transaction closes, lawyers routinely obtain from each party a certification (i) authorizing the deal and (ii) affirming that signing parties have authority to sign. The certification is usually obtained from an officer called a "secretary." No one seeks assurance that the secretary has authority to certify. Smart lawyers wonder whether they should trust the secretary, but they suppress doubts and go forward. Case law generally encourages their doubt suppression without explaining why — under agency law — secretaries have such authority. The full agency law analysis is not straightforward, but this paper explains it in full, mostly justifying the case law.
Growth stunting in single ventricle patients after heart transplantation.

BACKGROUND Malnutrition is common among children with single ventricle (SV) congenital heart disease (CHD). The impact of heart transplantation (HT) on nutritional status in SV patients is understudied. Our aim was to evaluate anthropometric changes in SV patients after HT, compared with those transplanted for cardiomyopathy (CM). METHODS We performed a single-center retrospective chart review of SV and CM patients < 18 years who underwent HT from January 01, 2010 to December 05, 2017. Wasting and stunting were defined as z-scores for weight-for-age or height-for-age ≤-2, respectively. Changes in these indices between HT and 3 years post-HT were analyzed. RESULTS Of 86 eligible patients, 28 (33%) had SV CHD and 58 (67%) had CM. Data were available at 3 years post-HT for 57 patients. At transplant, wasting was equally present in SV versus CM patients (7/28, 25% vs. 9/58, 16%, P = .22), which remained true at 3 years post-HT (2/16, 13% vs. 3/41, 7%, P = .61). At transplant, stunting was more common in SV than CM patients (17/28, 61% vs. 8/58, 14%, P < .001). At 3 years post-HT, 6 of 16 (38%) SV patients and 3 of 41 (7%) CM patients remained stunted (P = .01). Among all patients, wasting decreased from transplant to end-point (19% vs. 9%, P = .05), but stunting did not (29% vs. 16%, P = .2), such that wasting and stunting were associated at transplant (P < .001) but not at end-point (P = .17). CONCLUSIONS Longitudinal growth remains impaired for several years after HT in SV patients, even when weight gain is achieved, suggesting that some factors contributing to growth impairment persist despite resolution of SV physiology.
The 2017 Hurricane Public Health Responses: Case Studies Illustrating the Role of Centers for Disease Control and Prevention's Public Health Emergency Preparedness Program - Erratum.

The Centers for Disease Control and Prevention (CDC), Division of State and Local Readiness (DSLR), Public Health Emergency Preparedness(PHEP) program funds 62 recipients to strengthen capability standards to prepare for and respond to public health emergencies. Recipients use these PHEP resources in addition to CDC's administrative and scientific guidance to support preparedness and response program planning and requirements. It is expected that public health agencies develop and maintain comprehensive emergency preparedness and response plans in preparation for disasters such as hurricanes. The 2017 historic hurricane season highlighted how emergency planning and collaborative operational execution is important for public health agencies to effectively prepare for and respond to both the immediate and long-term population health consequences of these disasters. In 2017, the southeastern United States (US) and US Caribbean territories experienced 3 Category 4 or higher Atlantic hurricanes (Harvey, Irma, and Maria) within a 5-week period. This paper highlights selected case studies that illustrate the contributions and impact of jurisdictional emergency management planning and operational capacity supported by capability standards during the 2017 hurricane season. Although the magnitude of the 2017 hurricanes required public health officials to seek additional assistance, the following case studies describe the use of public health preparedness systems and recovery resources supported by the PHEP program.
To App or Not to App: A Business-To-Business Seller's Decision

Abstract Although business-to-business (B2B) selling firms increasingly realize the benefits of adoption and usage of B2B mobile applications (apps), few studies examine this topic. Building on the technology organization environment and the technology acceptance model adoption frameworks, this research provides an integrative framework to identify and investigate the key determinants of B2B mobile apps for sellers that have not implemented B2B mobile apps for their buyers to use in their decision making. The results from 360 marketing executives at B2B selling firms indicate that perceived usefulness, top management support, and competitive pressure positively influence the decision to adopt B2B mobile apps in the near future. In addition, relative advantage and perceived ease of use indirectly affect adoption of B2B mobile apps through perceived usefulness. The research findings provide several theoretical and managerial implications related to B2B mobile apps adoption.
Evaluation of Soft Clay Field Consolidation Using MEMS-Based In-Place Inclinometer–Accelerometer Array

The objectives of this study are: (1) to compare data recorded with a recently developed in-place inclinometer–accelerometer system to data measured with other established instrumentation through full-scale laminar box tests and field test sites, and (2) to evaluate possible causes for discrepancies between the measured and theoretical soil settlement at a bridge replacement site on soft clay. The performance of the three-dimensional (3D) micro-electro-mechanical systems (MEMS)-based in-place inclinometer–accelerometer array is evaluated for monitoring the settlement and lateral spreading of a very soft, 30-m-deep clay deposit at a New York State Department of Transportation (NYSDOT) bridge realignment site. Brief design details are given of the developed instrumentation system, which utilizes MEMS devices to measure angles relative to gravity, in addition to signals proportional to acceleration. The estimated theoretical accuracy of the system-displacement measurement is assessed empirically using thousands of datasets from several long-term field installations. This new instrumentation system was also included in a full-scale laminar box test of a sloping saturated fine sand deposit. This full-scale test provides a means of evaluating measured acceleration data. In all cases, data recorded with the developed in-place inclinometer–accelerometer system is compared to data measured with state-of-the-practice instrumentation. These comparisons were extremely favorable and justified the future use of this instrumentation for many geotechnical applications. This study also includes an evaluation of commercially available geotechnical software settlement predictions as compared to measured data at the NYSDOT bridge realignment site. The results of this study indicate that the effectiveness of the prefabricated vertical drains (PVDs) is not constant throughout the monitoring period and that the changes in effectiveness cannot be captured in commercial software using a constant ch.
Structural Competency in Mental Health and Medicine: A Case-Based Approach to Treating the Social Determinants of Health

Laynor reviews Structural Competency in Mental Health and Medicine: A Case-Based Approach to Treating the Social Determinants of Health edited by Helena Hansen and Jonathan Metzl.
Positive Childhood Experiences Promote School Success

Educational attainment has been demonstrated as a protective factor for the physical and mental health of children into adulthood, yet there has been limited research on the association between positive childhood experiences (PCEs) and school success. The purpose of this study is to examine the associations between PCEs and challenges to school success. This cross-sectional study used data of 33,450 children from the 2017–2018 National Survey of Children’s Health to examine PCEs and two challenges to school success (school absenteeism and repeated grades), using multivariable logistic regression analysis. The most prevalent types of PCEs were mentor for advice or guidance (89.8%), family resilience (81.1%), and after-school activity participation (79.8%). Children who participated in after-school activities had lower odds of reported school absenteeism (aOR 0.59; 95% CI 0.46–0.76) and repeating a grade (aOR 0.75; 95% CI 0.59–0.97) than their counterparts. Children who shared ideas with their caregiver had lower odds of repeating a grade (aOR 0.78; 95% CI 0.63–0.97) than children who did not share ideas with their caregiver. Children who lived in a supportive neighborhood were less likely to have reported school absenteeism than children who did not live in a supportive neighborhood (aOR 0.77; 95% CI 0.60–0.98). Participation in after-school activities had optimal associations with both school absenteeism and repeated grade, suggesting its potential protective effect for school success. Promoting PCEs at the school, family, and community levels may help address school absenteeism and grade retention.
A polarization system for persistent chemical detection

We report on the development of a prototype polarization tag based system for detecting chemical vapors. The system primarily consists of two components, a chemically sensitive tag that experiences a change in its optical polarization properties when exposed to a specific chemical of interest, and an optical imaging polarimeter that is used to measure the polarization properties of the tags. Although the system concept could be extended to other chemicals, for the initial system prototype presented here the tags were developed to be sensitive to hydrogen fluoride (HF) vapors. HF is used in many industrial processes but is highly toxic and thus monitoring for its presence and concentration is often of interest for personnel and environmental safety. The tags are periodic multilayer structures that are produced using standard photolithographic processes. The polarimetric imager has been designed to measure the degree of linear polarization reflected from the tags in the short wave infrared. By monitoring the change in the reflected polarization signature from the tags, the polarimeter can be used to determine if the tag was exposed to HF gas. In this paper, a review of the system development effort and preliminary test results are presented and discussed, as well as our plan for future work.
Structural studies of parathyroid hormone analogue with C-terminal aldehyde function.

Introduction The C-terminal function affects the structure (CD) and bioactivity of hPTH(1-28) analogues [1]. The hPTH with an amide C-terminus is more helical and bioactive than the analogue in a natural carboxyl form. The monomethylamide exhibited the greatest helicity and binding activity in contrast to the dimethylamide, which has helical parameters similar to the acid. Thus, removal of potential H-bond NH donors on the C-terminus destabilizes α-helix structure and decreases bioactivity. The CD profile of the aldehyde analogue is close to the bioactive monomethylamide, implying that the aldehyde function stabilizes the C-terminal helical structure of hPTH(1-28). However, the aldehyde, like the dimethylamide, demonstrated a weaker receptor binding than the monomethylamide. The structure of hPTH(1-28) analogues with C-terminal aldehyde, monoand dimethylamides were studied by high resolution 2D-NMR in aqueous solution at neutral pH.
Text classification for data loss prevention

Businesses, governments, and individuals leak confidential information, both accidentally and maliciously, at tremendous cost in money, privacy, national security, and reputation. Several security software vendors now offer "data loss prevention" (DLP) solutions that use simple algorithms, such as keyword lists and hashing, which are too coarse to capture the features what makes sensitive documents secret. In this paper, we present automatic text classification algorithms for classifying enterprise documents as either sensitive or non-sensitive. We also introduce a novel training strategy, supplement and adjust, to create a classifier that has a low false discovery rate, even when presented with documents unrelated to the enterprise. We evaluated our algorithm on several corpora that we assembled from confidential documents published on WikiLeaks and other archives. Our classifier had a false negative rate of less than 3.0% and a false discovery rate of less than 1.0% on all our tests (i.e, in a real deployment, the classifier can identify more than 97% of information leaks while raising at most 1 false alarm every 100th time).
A highly sensitive fluorescent sensor for palladium based on the allylic oxidative insertion mechanism.

Although palladium catalysts are powerful reagents in organic synthesis, hazardous palladium is often found in reaction products even after purifications. Thus, the detection of palladium is an important process in the production of fine chemicals and active pharmaceutical ingredients. We have developed a highly sensitive fluorescent sensor that is capable of detecting 1 ng of palladium quantitatively with the naked eye. Using this method, we were able to selectively detect palladium contamination in aspirin tablets (10 ppm Pd in 1 mg aspirin; mixed in the laboratory for this study), on the surface of flasks previously exposed to palladium, and in rocks containing palladium.
Brief, High Intensity Interventions with Children and Adolescents with Anxiety Disorders: Introductory Comments

In this series of brief papers, high intensity (HI) cognitive behavior therapy (CBT) interventions are reviewed for use with the anxiety disorders in youth. HI CBT approaches are defined as those t...
Association arrays in assessing forms of dependencies between bivariate random variables.

Abstract The bivariate distribution of pairs of random variables (X,Y) is said to be associated with respect to the classes of functions [unk] and [unk] if the product-moment correlation r[Φ(X),Ψ(Y)] ≥ 0 for all Φ € [unk] and Ψ € [unk]. In the case in which both [unk] = [unk] = [unk]* consist of all increasing functions, then the bivariate distribution of (X,Y) is said to be positive quadrant dependent. To apply the concept to data, I examine the correlations for classes of extremal functions that span by positive combinations the totality of functions Φ € [unk] and Ψ € [unk] to investigate whether the pair of random variables (X,Y) are associated with respect to [unk] and [unk] and to assess the relative degree (or strength) of association when comparing two sets of random variables (X,Y) and (Z,W).
Environmental Impact Statements—Worthwhile or worthless?

A geological evaluation of Environmental Impact Statements (EIS) reveals that many contain erroneous, irrelevant, misleading, and grammatically poor geological statements. We stress the need for use of pertinent geological information, such as general bedrock and soil conditions, geologic hazards, mineral and water resources, and regional seismicity, as well as the need for suggestions for remedial actions.
An incremental model for coal evaluation—I. Liquefaction

Abstract Because of differences in requirements for specific applications, coal values can vary greatly. We have devised a model to evaluate feedstock coals for hydrogenative liquefaction. In this method, incremental values are assigned to conventionally available quality parameters of coal based on stoichiometry, technology and general process economics. In addition, incremental values for variations in chemical reactivity, mechanical property and transportation cost were derived. These incremental values represent quantitative expressions for premium and discount of the coal with variations in quality. The relative values of coal may be calculated from these incremental values by using a simple procedure. The model provides a guide in technical and marketing studies. As a feedstock to liquefaction, the most desirable qualities of coal decrease in the order: high hydrogen content > low oxygen content > low sulfur content > low nitrogen content > low ash > low moisture. Thus, a W. Virginia bituminous A coal is highly valuable as a feedstock for liquefaction but a New Mexico sub-bituminous coal is not. The model may be updated, but it is relatively insensitive to technology and remains useful even if the technology should advance substantially. The major factors determining these incremental values are stoichiometric requirements which cannot be altered by technology.
Prolonged acute mechanical ventilation and hospital bed utilization in 2020 in the United States: implications for budgets, plant and personnel planning

Adult patients on prolonged acute mechanical ventilation (PAMV) comprise 1/3 of all adult MV patients, consume 2/3 of hospital resources allocated to MV population, and are nearly twice as likely to require a discharge to a skilled nursing facility (SNF). Their numbers are projected to double by year 2020. To aid in planning for this growth, we projected their annualized days and costs of hospital use and SNF discharges in year 2020 in the US. We constructed a model estimating the relevant components of hospital utilization. We computed the total days and costs for each component; we also applied the risk for SNF discharge to the total 2020 PAMV population. The underlying assumption was that process of care does not change over the time horizon. We performed Monte Carlo simulations to establish 95% confidence intervals (CI) for the point estimates. Given 2020 projected PAMV volume of 605,898 cases, they will require 3.6 (95% CI 2.7–4.8) million MV, 5.5 (95% CI 4.3–7.0) million ICU and 10.3 (95% CI 8.1–13.0) million hospital days, representing an absolute increase of 2.1 million MV, 3.2 million ICU and 6.5 million hospital days over year 2000, at a total inflation-adjusted cost of over $64 billion. Expected discharges to SNF are 218,123 (95% CI 177,268–266,739), compared to 90,928 in 2000. Our model suggest that the projected growth in the US in PAMV population by 2020 will result in annualized increases of more than 2, 3, and 6 million MV, ICU and hospital days, respectively, over year 2000. Such growth requires careful planning efforts and attention to efficiency of healthcare delivery.
Re-evaluation of the metabolism of oral doses of racemic carbon-6 isomers of formyltetrahydrofolate in human subjects.

The racemic mixture, [6 RS ]-5-formyltetrahydrofolate, is widely used clinically. In human subjects, orally-administered pure unnatural C-6 isomers, [6 R ]-5-formyltetrahydrofolate and [6 S ]-5,10-methenyltetrahydrofolate, were recently shown to be metabolized to the natural isomer, [6 S ]-5-methyltetrahydrofolate. We re-analysed the data from human studies published during the past four decades in which oral doses (≤10 mg) of racemic mixtures of these folates were used. We re-evaluated the data to determine whether these racemic mixtures are only 50 % bioactive or, as we now predict, more than 50 % bioactive. Our analyses indicate that, in human subjects, oral doses of the racemic mixture of the two formyltetrahydrofolates are 20–84 % more bioactive than would be predicted. These data are consistent with the following pathway: chemical conversion of these folates to 10-formyltetrahydrofolate; oxidation of 10-formyltetrahydrofolate to 10-formyldihydrofolate; subsequent enzymic conversion of 10-formyldihydrofolate to dihydrofolate by 5-amino-4-imidazolecarboxamide ribotide transformylase; and finally the well-established metabolism of dihydrofolate to [6 S ]-5-methyltetrahydrofolate. An additional review of the literature supports the in vivo oxidation of 10-formyltetrahydrofolate occurring to a certain extent, as 10-formyl-folic acid is rapidly formed after the administration of folic acid (pteroylglutamic acid) or 5-formyltetrahydrofolate in human subjects. The dogma that an oral dose of the unnatural C-6 isomer of 5-formyltetrahydrofolate is not bioactive in human subjects does not withstand scrutiny, most probably due to the previously unrecognized in vivo oxidation of 10-formyltetrahydrofolate. This discovery unveils new folate metabolism in human subjects.
Increased incidence of serendipitously discovered renal cell carcinoma

Abstract Objectives. To determine the proportion of renal cell carcinomas that are discovered serendipitously, and to compare the tumor stages of symptomatic versus incidental tumors. Methods. We reviewed the charts of 131 consecutive patients who had a nephrectomy for renal cell carcinoma between 1989 and 1993. We excluded from the numerator any patients with abdominal pain or mass related to the tumor, even if the diagnosis of renal cell carcinoma had not been entertained before imaging studies. Results. Eighty (61%) of 131 patients were diagnosed with renal cell tumors in the absence of flank pain, flank mass, or hematuria. Of these 131 patients, 31 (24%) presented with gross hematuria, 13 (10%) with flank pain, and 10 (8%) with flank or abdominal mass. Only 1 patient presented with the classic triad of flank pain, flank mass, and gross hematuria. Eighty-five percent of asymptomatic tumors were Stage I or II, and 77% of symptomatic tumors were Stage I or II. Conclusions. The great majority of renal cell tumors are found incidentally. The tumor stage is the same in the incidentally discovered cases as it is in the symptomatic cases.
Robust constrained trajectory tracking for magnetically controlled linear actuators with hysteresis

This paper extends the results of the dual-loop proportional and derivative controller discussed in [1] to magnetically controlled linear (MCL) actuator systems with state and input constraints and unknown but bounded disturbances. These actuators include both electromagnetic and smart actuators, such as moving coil, moving iron controllable, linear reluctance, magnetostrictive, and magnetically controlled shape memory alloy actuators. MCL actuators exhibit complex hysteresis with minor-loop closure and output saturation. In the aforementioned papers, the authors discuss how to utilize two output feedbacks for trajectory tracking control of disturbance-free hysteretic systems. In the case of MCL actuators, one can utilize both position feedback and induced voltage feedback to derive the input current. However, if the trajectory to be tracked is not known in its entirety, the output measurements are perturbed, or the plant contains parameters with uncertainties, then the system is no longer disturbance-free. The controller must achieve tracking under such exogenous disturbances while keeping the input current within its rated conditions. Here, sufficient conditions on controller gains are derived for ultimate bounded control while maintaining the input current within the rated conditions and maintaining closed-loop system stability for bounded input disturbance signals.
Observation of the collapse and revival of a Rydberg electronic wave packet.

We report an observation of the long-term evolution of a radially localized electronic wave packet formed by the coherent superposition of Rydberg states of atomic potassium. Initially, the wave packet can be described classically. Subsequent dephasing of the discrete states in the superposition leads to a loss of spatial localization so that the evolution can no longer be described classically. However, the wave packet revives at a later time. Theory and experiment show good agreement including an accurate measurement of the phase shift of the wave packet on revival.
How Do Transfers Survive after “Transfer Shock”? A Longitudinal Study of Transfer Student Departure at a Four-Year Institution

Prompted by the notion of “Transfer Shock”, numerous studies examined academic performance of transfer students at senior institutions. However, few studies are found that examine how the varying nature of semester GPAs impact subsequent persistence behavior of transfer students after the initial drop in their college GPAs. Using an institutional data set, this study longitudinally investigated departure behavior of transfer students at a senior institution. Particular attention was given to how entry at different times and semester GPAs affected transfer student departure. Results indicate that during their first semester, sophomore and junior transfer students were 73% less likely to depart than freshman transfer students. After controlling for explanatory variables, higher semester GPAs were positively associated with higher persistence rates throughout the observation period.
Integration of Clinical Data, Pathology, and cDNA Microarrays in Influenza Virus-Infected Pigtailed Macaques (Macaca nemestrina)

For most severe viral pandemics such as influenza and AIDS, the exact contribution of individual viral genes to pathogenicity is still largely unknown. A necessary step toward that understanding is a systematic comparison of different influenza virus strains at the level of transcriptional regulation in the host as a whole and interpretation of these complex genetic changes in the context of multifactorial clinical outcomes and pathology. We conducted a study by infecting pigtailed macaques (Macaca nemestrina) with a genetically reconstructed strain of human influenza H1N1 A/Texas/36/91 virus and hypothesized not only that these animals would respond to the virus similarly to humans, but that gene expression patterns in the lungs and tracheobronchial lymph nodes would fit into a coherent and complete picture of the host-virus interactions during infection. The disease observed in infected macaques simulated uncomplicated influenza in humans. Clinical signs and an antibody response appeared with induction of interferon and B-cell activation pathways, respectively. Transcriptional activation of inflammatory cells and apoptotic pathways coincided with gross and histopathological signs of inflammation, with tissue damage and concurrent signs of repair. Additionally, cDNA microarrays offered new evidence of the importance of cytotoxic T cells and natural killer cells throughout infection. With this experiment, we confirmed the suitability of the nonhuman primate model in the quest for understanding the individual and joint contributions of viral genes to influenza virus pathogenesis by using cDNA microarray technology and a reverse genetics approach.
A zebrafish retinal graded photochemical stress model.

Abstract Introduction In order to develop a model for investigating the genes that contribute to retinal degeneration, we examined the early graded photochemical stress response in the adult zebrafish (Danio rerio) retina and investigated the role of an NMDA inhibitor, thiokynurenate. Methods Following intravitreal injection of rose bengal (6 or 12 mg/mL), light (37 × 103 or 83 × 103 lx) was directed onto the central retina with and without 400 nM thiokynurenate. Histologic and electron microscopic analysis was performed at 2 and 4 h and gene expression analysis was carried out at 2, 4 and 6 h. Results Light and electron microscopy demonstrated a graded photochemical response in photoreceptor, nuclear, and ganglion cell layer thickness. Increased vacuolation of the inner plexiform layer was also observed. The inhibitor produced a distinct lesion pattern. Cellular stress genes were elevated in low and high lesions, while some homeobox gene expression was reduced with thiokynurenate. Discussion The phenotypic and genetic changes observed from this model can serve as a basis for understanding the pathology of retinal oxidative and cellular stress. These changes may aid our understanding of aging and macular degeneration.
Leptospirosis: case reports of an outbreak in Guyana

AbstractAlthough leptospirosis is a globally important zoonotic disease that affects humans on all continents, in both urban and rural areas, it often goes undiagnosed because its clinical manifestations are frequently non-specific. Even when leptospirosis is suspected, confirmation is made difficult by problems in isolating the causative organism in culture and by the low sensitivity of the available serological tests.Following torrential rains and flooding in January–February 2005, an outbreak of leptospirosis was suspected in Guyana, South America. Overall, 108 suspected cases presented at a medical post in the East Coast area of Guyana, and some of these cases are described in detail here. A better understanding of the clinical and paraclinical characteristics of leptospirosis should improve the recognition and appropriate treatment of the disease. Health education could reduce exposure, and physicians and primary healthcare workers could be made more aware of the signs and symptoms of leptospirosis.
Detecting fluorescence hot-spots using mosaic maps generated from multimodal endoscope imaging

Fluorescence labeled biomarkers can be detected during endoscopy to guide early cancer biopsies, such as high-grade dysplasia in Barrett's Esophagus. To enhance intraoperative visualization of the fluorescence hot-spots, a mosaicking technique was developed to create full anatomical maps of the lower esophagus and associated fluorescent hot-spots. The resultant mosaic map contains overlaid reflectance and fluorescence images. It can be used to assist biopsy and document findings. The mosaicking algorithm uses reflectance images to calculate image registration between successive frames, and apply this registration to simultaneously acquired fluorescence images. During this mosaicking process, the fluorescence signal is enhanced through multi-frame averaging. Preliminary results showed that the technique promises to enhance the detectability of the hot-spots due to enhanced fluorescence signal.
Antenna effective area and directivity viewed from photon theory

The lower limit on the effective area of an antenna and its directivity dependence on area are explained on the basis of the limited localizability of a photon and Heisenberg's principle of uncertainty.
Evolution of relativistic multiquark systems

The short-distance behavior of multiquark wave functions can be systematically computed in perturbative QCD. In this paper we analyze the wave function of a four-quark color-singlet bound state in SU(2${)}_{C}$ as an analogue to the six-quark problem in QCD. We first solve the QCD evolution equation for the multiquark distribution amplitude at short distances in the basis of completely antisymmetrized quark representations. The eigensolutions of the evolution kernel correspond to a spectrum of candidate states of the relativistic multiquark system. We then connect the four-quark antisymmetric representations and the eigensolutions to the physical two-cluster basis of SU(2${)}_{C}$ dibaryon (NN,N\ensuremath{\Delta},\ensuremath{\Delta}\ensuremath{\Delta}) and hidden-color (CC) components and derive constraints on the effective nuclear potential between two clusters. We also find anomalous states in the spectrum which cannot exist without substantial hidden-color degrees of freedom.
Narrow-band EUV multilayer coating for the MOSES sounding rocket

The Multi-order Solar EUV Spectrograph (MOSES) is a slitless spectrograph designed to study solar He II emission at 303.8 Angstroms, to be launched on a sounding rocket payload. One difference between MOSES and other slitless spectrographs is that the images are recorded simultaneously at three spectral orders, m = -1,0, +l. Another is the addition of a narrow-band multilayer coating on both the grating and the fold flat, which will reject out-of-band lines that normally contaminate the image of a slitless instrument. The primary metrics f a the mating were high peak reflectivity and suppression of Fe XV and XVI emission lines at 284 Angstroms and 335 Angstroms, respectively. We chose B4C/Mg2Si for our material combination since it provides better values for all three metrics together than the other leading candidates Si/Ir, Si/B4C or Si/SiC. Measurements of witness flats at NIST indicate the peak reflectivity at 303.6 is 38.5% for a 15 bilayer stack, while the suppression at 284 Angstroms, is 4.5x and at 335 Angstroms is 18.3x for each of two reflections in the instrument. We present the results of coating the MOSES flight gratings and fold flat, including the spectral response of the fold flat and grating as measured at NIST's SURF III and Brookhaven's X24C beamline.
A thermodynamic study of magnesium(II) interactions with mono- and dinucleotides

Abstract The equilibrium constants for the interaction between magnesium(II) and a number of mono- and dinucleotides (AMP, TMP, GMP, CMP, d-ApA, d-TpT, d-GpG, d-CpC, d-pTpT) have been determined accurately at 25.0 °C and an ionic strength of 0.2 M by a computerized, multiparamagnetic curve fitting analysis of pH titration curves. The data are consistent with inner sphere binding of magnesium(II) with the phosphate group. The presence of an additional base in those dinucleotides without a terminal phosphate causes a decrease in the magnesium(II) association constant.
In Vitro Susceptibility of Varicella Zoster Virus to Adenine Arabinoside and Hypoxanthine Arabinoside

Abstract The in vitro susceptibility of varicella zoster (VZ) isolates to adenine arabinoside (ara-A) and hypoxanthine arabinoside (ara-Hx) was determined in human skin fibroblasts. Using a system in which deamination was inhibited, and using a modified plaque reduction method, the antiviral activities of ara-A and ara-Hx were separated. The plaque inhibitory concentration of ara-A for all VZ isolates tested was 1 to 2 μg/ml and 80 to 100 μg/ml for ara-Hx. A comparison of antiviral activity based upon total plaque suppression gave a rate of 40 to 50:1, in favor of ara-A.
Reaction kinetics in dilute solutions of chain molecules carrying randomly spaced reactive and catalytic chain substituents. I. Estimation of ring closure probabilities from kinetic data and computer simulation

Acrylamide was copolymerized with small proportions of monomers containing a p-nitrophenyl ester group and a small amount of a monomer containing a pyridine residue. The hydrolysis of the ester groups was studied under conditions where the rate of the process was controlled by interaction with pyridine residues attached to the same chain. Variables studied included the mode of attachment of the ester groups to the chain backbone, the concentration of the catalytic pyridine residues in the chain and the fraction of the pyridine present in the unprotonated, catalytically active form. Kinetic data obtained at different pH values gave the same results if the extent of reaction was expressed as a function of the product of the experimental time and the fraction of pyridine residues in the basic form. This proves that the intramolecular process is not controlled by the rate at which cyclic conformations are formed but by their probability. The reaction deviated from first-order kinetics because the reactive groups had varying spacings from the catalytic groups. Experimental data were in good agreement with the kinetics derived by computer simulation if the probability of group interaction was made inversely proportional to the square of their separation along the chain molecule. Initial apparent first-order rate constants were about 40% of the value predicted on the basis of a simple theory based on the average extension of the polymer coils.
The dynamics of rotational isomerism in crystals as studied by vibrational spectroscopy

Abstract Vibrational spectroscopy is uniquely capable of determining the structure and dynamics arising from the rotational degrees of freedom in molecular solids. Vibrational spectroscopy is sensitive to phenomena occurring on a time scale between the slow scale of magnetic, resonance methods and fast scale of diffraction methods; a time scale appropriate for both internal and overall rotation. Rotational motion of molecules in crystals provide examples of very simple reactions. Our understanding of the spectra of reacting molecules can thus be tested on these systems, and we conclude that Redfield equations can describe such spectra. A rich variety of motional effects are described: (1) The libration of the water of hydration in sodium perchlorate which illustrates a simple reacting system. (2) The libration of the adamantane molecule in both its ordered and disordered crystal phases which illustrates intermolecular interactions in organic crystals and the consequences of disorder. (3) The libration of the ammonium ion in crystals of ammonium salts which illustrated both change of orientational position by tunneling and the subtle orientating effects of isotopic substitution. (4) The internal rotation in n-alkane crystals which illustrates the ability to determine conformers and the relationship between the occurrence of disordered conformers and the occurrence of phase transitions.
Chloroplast biogenesis: Quantitative determination of monovinyl and divinyl chlorophyll(ide) a and b by spectrofluorometry☆☆☆

Abstract Simultaneous equations for the determination of monovinyl (MV) and divinyl (DV) Chl a and b by spectrofluorometry in unsegregated mixtures of these tetrapyrroles were derived. The same equations can also be used for the quantitative determination of MV and DV chlorophyllide (Chlide) a and b in unpurified mixtures, after extraction of the Chls in hexane. The equations used differences in the Soret excitation maxima of these tetrapyrroles in ether at 77°K, in order to correct the Soret excitation overlap between MV and DV Chl(ide) a and between MV and DV Chl(ide) b.
Effects of prolactin and growth hormone on DNA synthesis of rat mammary carcinomas in vitro

Explants derived from mammary carcinomas of DMBA-treated female Sprague-Dawley rats were cultured for 5 days in Medium 199 containing insulin and corticosterone. The addition of ovine prolactin to the culture media resulted in a consistent significant increase in H3-thymidine incorporation into DNA. DNA synthesis of explants treated with either ovine or human growth hormone was intermediary to prolactin-treated cultures and control cultures. A combination of prolactin and human growth hormone often increased DNA synthesis above either hormone alone, suggesting a possible growth synergism between these peptides.
Herpes simplex virus-1 replication in histiotypic rotation-mediated reaggregated murine brain

Inbred mouse strains exhibit varying susceptibilities to severe herpes simplex virus (HSV)-1 -related neurologic disease. HSV-1 replication was examined in neural tissue obtained from mouse strains susceptible (A/J, SJL), moderately resistant (Balb/c), or resistant (C57BL/6) to severe HSV-1 disease. Reaggregated brain cultures were prepared from mechanically dissociated fetal mouse brains maintained with constant rotation. The resulting aggregates each contain neurons, astrocytes, oligodendrocytes, and microglia. These were inoculated with 10−2−104 plaque-forming units (pfu) HSV-1 Maclntyre/aggregate. Aggregates and media were harvested at 24, 48, 72, and 96 hr post-inoculation (p.i.) and assayed for virus production by plaque titration. Brain cultures prepared from A/J, SJL, Balb/c, and C57BL/6 mice supported HSV-1 replication equally well: by 96 hr p.i., titers of 106 pfu/ml were produced by each strain at each inoculum. ID50s were similar for A/J and C57BL/6 cultures. There was no increased capacity for HSV-1 replication or for permissiveness for HSV-1 infection in histiotypic brain cultures from mouse strains susceptible to severe HSV-1 disease. © 1995 Wiley-Liss, Inc.
Seasons within the Wildfire Season: Marking Weather-Related Fire Occurrence Regimes

Weather and climate contribute to the multidecadal, seasonal, and daily cycles of the potential for fire ignitions and for the severity of fires. We used a long-term dataset of weather parameters to characterize comparatively homogeneous periods, or subseasons, within the fire season. First, we conducted an exploratory analysis of weather conditions using the univariate t-test to determine if natural breaks in the weather conditions could be identified. Then, we used multivariate analysis of variance (MANOVA) of each calendar day, based on before and after periods of twelve days to identify the most distinct, natural breaks as expressed by the combination of weather variables as they change throughout the fire season. From this analysis, we identified six subseasons between March 1 and September 30 and explored the average weather conditions during each subseason. These results were partially validated against databases containing 29 years of historical fires and 16 years of historical Energy Release Component (ERC) data. From these results, we concluded that fire-weather can assume a uniform state for anywhere from two to six weeks, and then change into a considerably different regime. The quantitative establishment of these fire subseasons defines homogeneous periods of weather regimes that will improve the outputs of some fire models by controlling for seasonality. Our method for identifying subseasons could be applied by scientists using data from other regions to obtain subseason boundaries appropriate for their climatic regimes. The definition of subseasons also enhances our understanding of plant growth and development throughout the seasons, and provides managers with an objective tool to anticipate and adapt to the changing weather conditions.
Emission of Volatile Organic Compounds to the Atmosphere in the Solvent Sublation Process. I. Toluene

Abstract The mass of volatile organic compounds emitted to the atmosphere during solvent sublation was determined experimentally, using toluene as a test compound. It is shown that the emission of toluene to the atmosphere can be significantly reduced by using solvent sublation instead of air stripping under the same experimental conditions. The parameters which affect emission are the air flow rate, the nature and thickness of the organic layer, and the nature and concentrations of the co-solutes. Emissions are reduced as the thickness of the organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emission to a greater extent than does paraffin oil. The emission of toluene during solvent sublation is further reduced as the air flow rate is lowered. The rate of toluene removal from water in solvent sublation is somewhat higher than in air stripping under the same experimental conditions. The effect of added anionic or cationic surfactants or alcohol wa...
Failure Mechanics—Part III: A Call to Service With Solid Mechanics

The case is made for the present and future revitalization of the discipline of materials failure, including needed educational reforms.
Applications of the Sherman-Morrison Matrix Inversion Formula in Linear and Non-Linear Vibrations, Controls and Acoustics

Applications of the Sherman-Morrison matrix inversion formula are reviewed and demonstrated for several problems in sound and vibration control. The inversion formula enables one to easily separate the effect of a perturbation or subcomponent on the dynamic behavior of the overall system. Applications of this technique that are demonstrated here include: identifying optimal PZT electrical shunt parameter values to minimize sound radiation from a PZT-plate structure, identifying the optimal location and parameter values of a tuned dynamic vibration absorber attached to a multi-degree of freedom, damped system, and identifying and quantifying an isolated non-linearity in an otherwise linear system. Extensions to active control system design are also discussed.Copyright © 2003 by ASME