cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal Control of Ordinary Differential Equations

This chapter discusses the optimal control of ordinary differential equations. The formulation of the standard problem; existence of minimizing relaxed and approximate solutions; necessary conditions for a minimum; contingent equations and equivalent control functions; unbounded contingent sets and compactified parametric problems; variable initial conditions; and free time, infinite time, staging, and advance-delay differential problems are the major topics covered in the chapter. Most present-day space vehicles have multiple stages, that is, rocket engines mounted on top of one another with the payload on top of the highest stage. The lowest stage is activated first, and when its fuel is used up, it is jettisoned. When needed, the thrust is provided by the second stage and then the following ones. The control of a k -stage rocket thus involves k additional parameters, that is, the times when each of the rocket stages is discarded.
Lawnmowers Versus Children: The Devastation Continues.

Accidents with lawnmowers can cause mutilating injuries to children. Safety guidelines regarding the use of lawnmowers were promoted by professional organizations beginning in 2001. The Pennsylvania Trauma Systems Foundation maintains a database including all admissions to accredited Levels 1 to 4 trauma centers in the state. The annual rates of admission for children in our state and the severity of injuries subsequent to introduction of safety guidelines have not been reported, to our knowledge. Ride-on lawnmowers have been associated with more severe injuries in children. We asked: (1) What was the incidence of hospital admissions for children with lawnmower-related injuries during 2002 to 2013 and did the incidence vary by age? (2) What was the severity of injuries and did the severity vary by age? (3) How often did these injuries result in amputation? (4) What types of lawnmowers were involved? This was a retrospective study using a statewide trauma registry. We queried the Pennsylvania Trauma Outcome Study database for children 0 to 17 years old admitted to trauma centers in Pennsylvania between January 2002 and January 2014 with injuries resulting from lawnmower-related accidents. All accredited Levels 1 to 4 trauma centers in the state are required to submit their data to the Pennsylvania Trauma Systems Foundation which maintains the Pennsylvania Trauma Outcome Study database. Demographic information, Injury Severity Scores, International Classification of Diseases procedure codes, and injury location codes were recorded. Type of lawnmower was determined from the narratives and was identified in 60% (119/199) of patients. Traumatic and surgical amputations performed during the index hospitalization were included in the analysis. Information on later surgeries was not available. Subjects were stratified by age: 0 to 6, 7 to 12, and 13 to 17 years old. The incidence of lawnmower injuries in Pennsylvania was a median five of 100,000 children (range, 4–12/100,000) during the study period. The median age was 6 years (range, 1–17 years). The median Injury Severity Score was 4 (range, 1–75). Children 0 to 6 years old had higher median Injury Severity Scores (median, 8; range, 1–75) compared with those 13–17 years old (median, 4; range, 1–20; difference of the medians, 4; p < 0.001). A total of 53% of the patients (106/199) underwent at least one amputation. There were 83 amputations in or of the foot, 18 in the leg, 14 in the hand, and three in the arm. Ride-on lawnmowers accounted for 92% (110/119) of mowers identified by type. The incidence of serious injuries to children owing to lawnmower-related trauma did not change during the 12-year study period. If children younger than 6 years had not been near the lawnmower and those younger than 12 years had not been operating one, at least 69% of the accidents might have been prevented. We recommend annual publicity campaigns during spring to remind the public of the dangers of lawnmowers to children. Level IV, therapeutic study.
Verifying equivalence of digital signal processing circuits

Verifying the equivalence of digital signal processing circuits is not only important in designing architectures, but also in designing secure circuits. If the functionality equivalence cannot be easily verified, then the security can be improved. In this paper, we present novel use of high-level transformations to hide the functionalities of DSP circuits, which include retiming, pipelining, folding, unfolding, and interleaving. We show that we can design circuits which are harder to reverse engineer by adopting high-level transformations. However, other techniques, such as modifying the switch instances, adding dummy loops, and manipulating inputs, can also be exploited for both verifying equivalence as well as designing secure circuits.
Mechanism of Ru(II)-Catalyzed Rearrangements of Allenyl- and Alkynylcyclopropanols to Cyclopentenones

A comparison study of the Ru(II)-catalyzed rearrangements of allenyl- and alkynylcyclopropanols to the corresponding cyclopentenones has been undertaken with the aid of an alkyl substituent on the three-membered ring. These ring expansion reactions proceed with exceptional regioselectivity irrespective of the cis/trans stereochemistry of the substituents on the three-membered ring. β-Carbon elimination is the common feature in the absence of a chelating group at the 4′-position in the alkyne chain.
Optimizing the treatment of ovarian cancer: Neoadjuvant chemotherapy and interval debulking versus primary debulking surgery for epithelial ovarian cancers likely to have suboptimal resection.

Abstract Objective To: a) identify prognostic factors in patients with epithelial ovarian cancer treated with neoadjuvant chemotherapy (NACT) and interval debulking surgery (IDS), and b) compare post-surgical survival between patients treated with NACT/IDS for presumed unresectable disease and stage IIIC/IV patients who underwent suboptimal primary debulking surgery (PDS). Methods This was a retrospective study of consecutive stage IIIC or IV patients undergoing IDS after NACT at Mayo Clinic from January 2007 to December 2013. A subset of patients receiving NACT/IDS for the indication of unresectable disease were matched 1:1 on age and stage to a cohort of patients who underwent suboptimal PDS between 2003 and 2011. Hazard ratios and corresponding 95% confidence intervals were estimated from Cox proportional hazards models. Results We identified 87 patients treated with NACT/IDS: the median OS and PFS following surgery was 2.4 and 1.0years, respectively. Factors associated with significantly worse OS were older age (adjusted HR 1.60 per 10-year increase in age, 95% CI 1.18, 2.16) and elevated CA-125 before IDS (adjusted HR 2.30 for CA-125 >35U/mL, 95% CI 1.25, 4.23). Number of adjuvant chemotherapy cycles administered did not have a significant effect on survival. In the matched cohort analysis of presumed unresectable cases undergoing NACT/IDS vs suboptimal PDS cases (n=45 each), the NACT/IDS group had a significant OS advantage (HR 0.53; 95% CI 0.32, 0.88), and fewer patients experienced a 30-day postoperative Accordion grade 3/4 complication (11% vs 36%, P=0.01). Conclusions Younger age and normalization of CA-125 prior to IDS are associated with improved survival with NACT/IDS. For primary EOC where resection to residual disease of 1cm or less is unlikely, NACT/IDS is associated with improved survival and reduced perioperative morbidity compared to PDS. As these patients are likely best served by NACT/IDS, more reliable predictors of resectability would be valuable.
Studies of the very early responses of a receptor tyrosine kinase to growth factor binding and their application to the purification and identification of proteins that are tyrosine phosphorylated in the growth factor response

Growth factors whose effects are mediated via receptor tyrosine kinases induce changes in these receptors and other membrane and cytoplasmic proteins within 30 sec of addition. This paper describes kinetic analyses of these changes using the colony stimulating factor-1 (CSF-1)/CSF-1 receptor system and indicates how these studies have been useful in developing methods for the purification and identification of proteins that are rapidly phosphorylated in tyrosine in response to growth factor addition.
Agricultural Biotechnology and Crop Productivity: Macro-level Evidences on Contribution of Bt Cotton in India

While farm-level empirical studies demonstrate the contribution of Bt technology in increasing crop productivity, there are still questions about its contribution to long-term growth in productivity at the macro-level. Our study examines major technological and seed policy breakthroughs relevant for the cotton crop, and reviews their impact on overall performance of the cotton sector and agricultural biotechnology industry in India. Using state-level panel data on cotton production from all the major cotton-producing zones, we provide empirical evidences on structural change in the cotton yield since the introduction of Bt technology and its impact on long-term growth in productivity at the national level.
A Novel Latching Relay Fabricated Using an Oxide Molded Tungsten Process

In this paper we describe an oxide molded tungsten process applied to the fabrication of a novel latching relay. The steps in the process are: deposition of a sacrificial oxide, patterning of the oxide, filling of the resulting mold with a blanket film of tungsten using chemical vapor deposition (CVD), and then the removal and planarization of excess tungsten through chemical mechanical polishing (CMP). The process for the incorporation of dielectric isolation has also been developed. The resulting tungsten structures are under high tensile stress, which appears to be compensated in process by the compressive stress of the oxide mold. All the steps are low temperature and the entire process is backend CMOS compatible. This process has been used to fabricate a latching relay which relies on the internal stress of the tungsten and always generates force in a pulling mode. Parts have been successfully fabricated and tested, the devices generate very high forces for a MEMS device and give reasonable contact resistances even without noble metal contacts.
The Case for Cold-Calling: Initiating Active Participation in the Classroom

After ten years teaching my large lecture course, Infancy and Child Development, I found myself at a roadblock. Disillusioned with the passivity adopted by my students in the classroom, I knew some...
A Planning Model for Disaster Response

Two major characteristics of disaster complicate man’s ability to respond to them effectively. First, they happen with little or no warning, and second, disasters are unique in time and place. Therefore, to best address a planning model that provides a timely and efficient approach to response, it is necessary to review the experiences of previous actual incidences, extract the common elements, and evaluate the response performance. Using this process, the following model was developed.
Separation of Epithelial Cells from Gastric and Intestinal Mucosa

Publisher Summary Cellular heterogeneity underlies the integrated regulatory function of the gastrointestinal tract. The heterogeneity of gastrointestinal epithelium dictates the use of isolated cell preparations in studying the physiology of a specific cell type. The gastric glandular region is characterized by a complexity of epithelial cells, including mucous cells, chief cells, parietal cells, mast cells, and endocrine cells. The use of in vivo models to investigate gastrointestinal cell physiology cannot unravel the existing functional complexity. The use of isolated cell systems provides an improved method for defining the regulation of epithelial function at the cell level. Dispersed mucosal cells, separated and enriched for a specific cell type, can be used to characterize cell surface receptors and to elucidate receptor-mediated mechanisms of cell activation. It is essential to relate the physiological importance of receptors and release mechanisms identified using isolated cell systems to the integrated regulation of the gastrointestinal tract. Receptor-mediated regulation of cell function is generally linked to either cAMP-dependent or calcium-dependent mechanisms. The use of isolated cell fractions highly enriched for a particular cell type is critical for elucidating the role of intracellular second-messenger pathways.
COMPARATIVE REGULATION OF α1, 4-GLUCAN SYNTHESIS IN PHOTOSYNTHETIC AND NON-PHOTOSYNTHETIC SYSTEMS

ABSTRACT ADPglucose (ADPG) pyrophosphorylase catalyzes the biosynthesis of ADPglucose from ATP and α-glucose-1-P and is the first unique enzyme in the bacterial glycogen and plant starch biosynthetic pathways. It is activated by glycolytic intermediates in most if not all bacterial and plant extracts and may be inhibited by 5′-AMP, ADP and/or P i (see Preiss, J., in Adv. in Enzymol., Vol. 46, pp. 317-381 (1978)). The major activators are pyruvate (usually observed for the photosynthetic bacterial enzyme), 3-P-glycerate (the major activator for the higher plant, algal and blue green bacterial ADPG pyrophosphorylases), fructose-6-P and fructose-P 2 . The last two activators are usually observed for ADPG pyrophosphorylases from bacteria that catabolize sugars via the Entner Doudoroff and glycolytic pathways, respectively. Thus, the activator specificity of the bacterial and plant ADPglucose pyrophosphorylases roughly correlates with the ability of the organism to metabolize various carbon sources for energy and growth. The activator specificity may also be used in certain classes of organisms as a taxonomic marker. Causal data with plants and bacteria correlating fluctuation of inhibitor and activator concentrations in vivo with rates of α-glucan synthesis strongly suggest that the activator and inhibitor effects observed in vitro are physiologically operative. Furthermore isolation of a class of mutants of E. coli and S. typhimurium altered in their ability to accumulate α-glucan can be correlated with altered affinities of the inhibitor AMP and the activator, fructose-P 2 for the organism's ADPglucose pyrophosphorylase. Covalent attachment of [ 3 H] pyridoxal-P (PLP) to the activator binding site of the E. coli enzyme has enabled us to determine the amino acid sequence around the activator site and determine it to be a lysyl residue 37 amino acid residues from the amino-terminus of the enzyme. The sequence is: NH 2 -Val-Ser-Leu-Glu-Lys-Asn-Asp-His-Leu-Met-Leu-Ala-Arg-Gln-Leu-Pro-Leu-Lys-Ser-Val-Ala-Leu-Ile-Leu-Ala-Gly-Gly-Arg-Gly-Thr-Arg-Leu-Lys-Asp-Leu-Thr-Asn-Lys-(PLP)-Arg-Ala-Lys-Pro-Ala-Val-His-Phe-Gly-Gly-Lys….
Prevalence and antimicrobial resistance profile of Campylobacter isolated from conventional and antibiotic free swine farms in three geographic locations

Background: The prevalence and antimicrobial resistance of Campylobacter were exammed from swine reared in conventional and ant1m1crobial-free (ABF) production systems m three geographical locations: North Carolina (NC), Ohio (OH) and Wisconsin (WI). Methods: A total of 1500 p1gs and 1930 carcass swab samples were evaluated for the prevalence of Campylobacter. Fecal samples from 662 pigs from NC (370 conventional farms and 292 ABF farms), 379 from OH (268 conventional and 111 ABF) and 459 from WI (160 conventional and 299 ABF) were included. Antimicrobial susceptibility testing was performed using agar dilution method against a panel of six antimicrobials. Results: Campylobacter was commonly found in swine herds 1n all the three states w1th a prevalence of 54.2% (NC), 54.1% {OH) and 58.2% (WI). The prevalence of Campylobacter in conventional farms (56.1 %) was not Significantly different from ABF farms (54.6%) (p > 0 05) However, the prevalence of Campylobacter m WI farms was higher m conventional farms (70 6%) th an ABF (51 .5%) (p 4 mg/L} was h1gher among OH and WI isolates than NC Erythromycin and tetracycline resistance was significantly higher in conventional farms than ABF Farms (p<0.05). Cipronoxacin and Nalidixic acid res1stance was more common 1n ABF farms (p<0.05). The predominant resistance patterns were erythromycin­ tetracycline (Ery-Tet) and tetracycline only (Tel}. Discussion· Th1s study showed h1gh prevalence of Campylobacter among sw1ne herds m the three states with no s1gn1ficant difference by geographical locations and product1on systems (regardless of the antimicrobial use status). The h1gh proport1on of c1pronoxacm res1stant 1solates from ABF herds may have important Implications on the potential role of risk factors other than mere ant1m1crob1al use for production purposes and probably producer compliance.
Modulation of Sympathetic Overactivity to Treat Resistant Hypertension

To review the role and evidence for sympathetic overactivity in resistant hypertension and review the therapies that have been studied to modulate the sympathetic nervous system to treat resistant hypertension, with a focus on non-pharmacologic therapies such as renal denervation, baroreflex activation therapy, and carotid body ablation. Based on the two best current techniques available for assessing sympathetic nerve activity, resistant hypertension is characterized by increased sympathetic nerve activity. Several device therapies, including renal denervation baroreflex activation therapy and carotid body ablation, have been developed as non-pharmacologic means of reducing blood pressure in resistant hypertension. With respect to renal denervation, the technologies for renal denervation have evolved since the unfavorable results from the HTN-3 study, and the revised technologies are being actively studied. Data from the first phase of the SPYRAL HTN Clinical Trial Program have been published. Results from the SPYRAL HTN-OFF MED trial suggest that ablating renal nerves can reduce blood pressure in patients with untreated mild-to-moderate hypertension. The SPYRAL HTN-ON MED trial demonstrated the safety and efficacy of catheter-based renal denervation in patients with uncontrolled hypertension on antihypertensive treatment. Interestingly, there was a high rate of medication non-adherence among patients with hypertension in this study. One attractive alternative to radiofrequency ablation is the use of ultrasound for renal denervation. Proof of concept data for the Paradise endovascular ultrasound renal denervation system was recently published in the RADIANCE-HTN SOLO trial. The results of this trial indicate that, among patients with mild to moderate hypertension on no medications, renal denervation with the Paradise system results in a greater reduction in both SBP and DBP at 2months compared with a sham procedure. Overall reductions were similar in magnitude to those noted in the SPYRAL HTN-OFF MED study. With respect to carotid body ablation, there is an ongoing proof of concept study that is investigating the safety and feasibility of ultrasound-based endovascular carotid body ablation in 30 subjects with treatment-resistant hypertension outside of the USA. The sympathetic nervous system is an important contributor to resistant hypertension. Modulation of sympathetic overactivity should be an important goal of treatment. Innovative therapies using non-pharmacologic means to suppress the sympathetic nervous system are actively being studied to treat resistant hypertension.
Selection Bias and Endowment Effect

Natalie was a 26-year-old woman who suffered from depression. She was not suicidal and was still able to go to work. However, she was tired much of the time and found little joy in activities she formerly found pleasurable. She wanted to treat her condition “naturally,” and found a practitioner of holistic medicine whose blogs she admired. She wrote to the doctor and was sent long questionnaire, shown below, about her symptoms, beliefs, and willingness to change her lifestyle.
Association of Preoperative, Subjective Pediatric Tonsil Size With Tonsillectomy Outcomes: A Systematic Review

Importance Tonsil size assessment on physical examination is often used as a key component of clinical decision-making, specifically in estimating the success or failure of adenotonsillectomy surgery. The accuracy of this approach is not specifically known. Objective To systematically review the biomedical literature for data comparing subjective preoperative tonsil (and adenoid) size (0- to >4-point scale) with adenotonsillectomy outcomes using polysomnography and/or quality of life outcomes. Evidence Review A PubMed and Embase search was conducted from June 1, 2018, through November 1, 2018, to identify articles comparing preoperative subjective tonsil and adenoid size with surgical outcomes. Key search terms includedadenotonsillectomy,tonsil size,Brodsky scale,apnea-hypopnea index,OSA-18,polysomnography, andquality of life, with limits of 0 to 18 years of age. Inclusion criteria included articles on pediatric patients only, articles on patients who underwent tonsillectomy or adenotonsillectomy, and articles that included presurgical and postsurgical data. Exclusion criteria included patients who received surgery beyond adenotonsillectomy and studies that did not compare tonsil and adenoid size grades with surgical outcomes. Findings A total of 27 studies were included in the final data set. The mean sample size was 79.7 (range, 17-250), and the mean age was 6.3 years (range, 4.2-12.8 years). Case series was the predominant study design (20 studies). Fourteen studies specifically excluded obesity and craniofacial syndromes, whereas 2 studies addressed patients with trisomy 21 only, and 5 studies focused on patients with obesity. Outcome measures included polysomnography (19 studies), Obstructive Sleep Apnea 18 survey (4 studies), Obstructive Sleep Apnea 6 (1 study), oxygen desaturation index (1 study), and overnight pulse oximetry (1 study). Ten studies conducted postoperative evaluations within 90 days of the intervention, and 17 studies had greater than 90-day follow-up. A total of 22 of the 27 studies (81.5%) concluded that there was no association between tonsil and adenoid size and surgical outcome, whereas 5 studies (18.5%) concluded that there was an association. Studies that found no association had a higher mean quality score than those that found an association (15.6 vs 14.5; difference in means, 1.13; 95% CI, 0.07-2.19). Conclusions and Relevance Most published clinical evidence suggests that subjective tonsil and adenoid size is not reliably associated with adenotonsillectomy success or failure because success rates are typically high regardless of tonsil size. Physicians should understand the potential limitations of using tonsil size alone as the key component of clinical decision-making for adenotonsillectomy.
Special Topic on Spin–Orbit Coupling Effects for Advanced Logic and Memory

The first effect resulting from spin–orbit coupling (SOC), the spin Hall effect (SHE), was discovered by Dyakonov and Perel nearly 50 years ago. However, it belonged largely to the realm of fundamental physics rather than technology. Only ten years ago, I asked a university professor presenting on SHE experiments a question about possible device applications. The answer was that it is up to industrial technologists to figure out. The breakthrough came in 2011 from the Barcelona–Grenoble collaboration and from the Cornell University group as the magnetization was switched via the spin–orbit torque (SOT). In the following years, the explosive growth of both theoretical research and experimental research followed.
Role of CD68 immunohistochemistry in categorizing benign nonmesothelial cell population and refining “atypical” category in serous fluid cytology

Background Body fluids are rich in histiocytes and may mimic atypical epithelial cells morphologically. Histiocytes can pose a significant challenge in serous fluid cytology as they tend to appear atypical due to prolonged accumulation in serous fluids in vivo and processing by liquid-based cytology in vitro. Not many studies have documented the utilization of histiocytic marker such as CD68 in serous fluid cytology, which can subsequently reduce the "atypical" diagnostic category. Methods One thousand one hundred and twenty-nine cases of serous fluid cytology from 2016 to 2019 were reviewed and reclassified based on proposed classification of the international system for reporting serous fluid cytology. There were 133 cases with atypical diagnoses, out of which 51 cases had cellblocks. An immunohistochemistry (IHC) panel, including two mesothelial markers, two epithelial markers, and one histiocytic marker was applied to the atypical samples. Same IHC panel was utilized to evaluate 15 cases each from negative for malignancy (NFM), suspicious for malignancy (SFM), and malignant (MAL) categories for further comparison. Results After reevaluation of the cytology material with IHC stains, 924 (82%), 133 (12%), 23 (2%), and 49 (4%) of the cases were reclassified as NFM, atypia of uncertain significance, SFM, and MAL, respectively. Twenty-five out of 51 atypical cases (49%) were downgraded to "benign" after reevaluation with CD68 IHC. Conclusion Histiocytes can mimic atypical epithelial cells in body fluids. Effective utilization of CD68 IHC will be beneficial in further refining the "atypical" diagnostic category in serous fluid cytology.
Analysis of Temperature Characteristics of Electric Field Distribution in Oil-Paper Insulation

The converter transformer is a vital equipment in the HVDC transmission system, which connects a DC system and an AC system. In another word, it will withstand many kinds of yoltages, such as AC, DC, AC+DC, poplarity reversal voltage. The converter transformer will have a higher fault ratio when withstanding a poplarity reversal voltage. So more and more experiments on characteristics of converter transformer are carried out by researchers home and abroad. But the results are perfect, there is no systematic theory until now. In this paper, Ansys software is used to establish the model of oil-paper insulation placed between to plate electrodes to simulate electric field distribution under poplarity reversal voltage. Three temperature points are used to simulate the influence of different insulation resistivity values on the electric field distribution of oil-paper insulation under different temperatures.
Effects of fact-checking social media vaccine misinformation on attitudes toward vaccines.

Social media vaccine misinformation can negatively influence vaccine attitudes. It is urgent to develop communication approaches to reduce the misinformation's impact. This study aimed to test the effects of fact-checking labels for misinformation on attitudes toward vaccines. An online survey experiment with 1198 participants recruited from a U.S. national sample was conducted in 2018. Participants were randomly assigned to six conditions: misinformation control, or fact-checking label conditions attributed to algorithms, news media, health institutions, research universities, or fact-checking organizations. We analyzed differences in vaccine attitudes between the fact-checking label and control conditions. Further, we compared perceived expertise and trustworthiness of the five categories of fact-checking sources. Fact-checking labels attached to misinformation posts made vaccine attitudes more positive compared to the misinformation control condition (P = .003, Cohen's d= 0.21). Conspiracy ideation moderated the effect of the labels on vaccine attitudes (P = .02). Universities and health institutions were rated significantly higher on source expertise than other sources. Mediation analyses showed labels attributed to universities and health institutions indirectly resulted in more positive attitudes than other sources through perceived expertise. Exposure to fact-checking labels on misinformation can generate more positive attitudes toward vaccines in comparison to exposure to misinformation. Incorporating labels from trusted universities and health institutions on social media platforms is a promising direction for addressing the vaccine misinformation problem. This points to the necessity for closer collaboration between public health and research institutions and social media companies to join efforts in addressing the current misinformation threat.
Effects of Different Urban-Vegetation Morphology on the Canopy-level Thermal Comfort and the Cooling Benefits of Shade Trees: Case-study in Philadelphia

Abstract Urban morphology directly influences heating or cooling rate in street canopies. This paper assessed cooling benefits of street-trees in Philadelphia city, PA considering morphological elements. We assessed summertime thermal comfort for humid subtropical climate (i.e. Philadelphia) by studying human-biometeorological parameters such as Mean-radiant temperature (Tmrt) and Physically Equivalent Temperature (PET) utilizing Rayman model. This paper will; 1. Quantify impacts of built environment with and without existing vegetation on pedestrian level temperature, 2. Observe impacts of Tmrt, surface temperature (Ts), PET and global radiation at road intersections in five different scenarios where urban canopies are characterized as: a) built environment without vegetation (BE), b) built environment with existing vegetation (BEEV), c) built environment with additional vegetation after 1-year (BEAV-1), d) built environment after 5-years (BEAV-5) and e) built environment after 10-years growth period (BEAV-10). Compared results with the BE scenario suggest that, planting trees in residential and mixed-use sites with higher Sky-view factor (SVF) can improve pedestrian comfort in the long-term by reducing Tmrt, and PET, compared to the commercial sites with lower SVF and Ts. Mixed-use sites were observed to provide highest thermal comfort and further benefit from tree plantation, while commercial sites receive lowest cooling benefit from street trees.
Comparison of e-cigarette use prevalence and frequency by smoking status among youth in the United States, 2014-19.

BACKGROUND AND AIMS Reports of youth e-cigarette use often do not disaggregate by underlying smoking status. This study compared annual 2014-19 youth estimates of past 30-day e-cigarette use prevalence and frequency by smoking status in the United States. DESIGN Nationally representative, cross-sectional, school-based survey [National Youth Tobacco Surveys (NYTS)]. General linear models accounting for complex survey design compared e-cigarette use prevalence by smoking status by year, overall and stratified by frequency, separately for high school (HS) and middle school (MS) students. The 2019 survey was analyzed separately because of its change in survey methodology. SETTING MSs and HSs in the United States. PARTICIPANTS A total of 116 704 students from 1268 schools, ages 9-19. MEASUREMENTS Students self-reported (paper 2014-18, electronic 2019) ever and past 30-day (current) use of e-cigarettes and cigarettes, as well as frequent use (20-30 days of month). FINDINGS From 2014 to 2018, current e-cigarette use prevalence increased among never, current and former smokers in HS, but only among never and current smokers in MS (each P-value < 0.001). E-cigarette use increases for current HS smokers were primarily among frequent e-cigarette users. In 2018, the absolute number of HS frequent users who were never or former smokers (420 000 combined) surpassed current smokers (370 000). In 2019, current e-cigarette use prevalence for never, former and current smokers was 17.5% [95% confidence interval (CI) = 16.0-19.0], 53.6% (95% CI = 45.2-61.9) and 85.8% (95% CI = 81.6-89.9) for HS students, respectively, and 6.8% (95% CI = 5.9-7.7), 40.8% (95% CI = 34.7-47.0) and 78.0% (95% CI = 71.9-84.2) for MS students. That year, the number of HS never (420 000) and former smokers (570 000) using e-cigarettes frequently eclipsed that of current smokers (390 000). CONCLUSIONS E-cigarette use prevalence and frequency among youth vary by smoking status, with highest levels of use among current smokers. However frequent e-cigarette use among never smokers and former smokers has increased.
Global Trade and Food Safety: Winners and Losers in a Fragmented System

How food safety is addressed in the world trade system is critical for developing countries that continue to rely on agricultural exports. An analysis shows that adopting a worldwide standard for a toxin affecting nuts and grains could increase trade in these commodities by $38 billion compared with levels under today's widely divergent national standards. Food safety standards and the tradeoff between these standards and agricultural export growth are at the forefront of the trade policy debate. How food safety is addressed in the world trade system is critical for developing countries that continue to rely on agricultural exports. In a fragmented system of conflicting national food safety standards and no globally accepted standards, export prospects for the least developed countries can be severely limited. Wilson and Otsuki examine the impact that adopting international food safety standards and harmonizing standards would have on global food trade patterns. They estimate the effect of aflatoxin standards in 15 importing countries (including 4 developing countries) on exports from 31 countries (21 of them developing). Aflatoxin is a natural substance that can contaminate certain nuts and grains when storage and drying facilities are inadequate. The analysis shows that adopting a worldwide standard for aflatoxin B1 (potentially the most toxic of aflatoxins) based on current international guidelines would increase nut and cereal trade among the countries studied by $6.1 billion compared with 1998 levels. This harmonization of standards would increase world exports by $38.8 billion. This paper - a product of Trade, Development Research Group - is part of a larger effort in the group to expand empirical and policy understanding of the link between trade, development, and standards. The authors may be contacted at jswilson@worldbank.org or totsuki@worldbank.org.
The Anatomy of Valuing Stock in Closely Held Corporations: Pursuing the Phantom of Objectivity into the New Millennium

Valuing stock in closely-held corporations is perplexing for most courts. Valuation techniques are complex and courts are often unfamiliar with accounting and financial theory. However, valuation of stock in close corporations is required in order to assess income taxes from purchases or sales, for corporations which are reorganizing, or when someone dies and bequeaths shares in a closely held corporation which are subject to estate tax. Gifts of shares in a closely-held corporation are also subject to taxation. No objective standard exists to guide judges, academic commentators and practitioners. Although both the IRS and the courts strive to conform to meaningful financial theories and legal precedents, the resulting valuations often differ. This paper discusses a number of different valuation approaches that the courts have followed, particularly with respect to contested valuations in income, estate, and gift taxation cases.
Aspects Of The Atmospheric Surface Layers On Mars And Earth

The structures of mean flow and turbulence in the atmospheric surface boundary layer have been extensively studied on Earth, and to a far less extent on Mars, where only the Viking missions and the Pathfinder mission have delivered in-situ data. Largely the behaviour of surface-layer turbulence and mean flow on Mars is found to obey the same scaling laws as on Earth. The largest micrometeorological differences between the two atmospheres are associated with the low air density of the Martian atmosphere. Together with the virtual absence of water vapour, it reduces the importance of the atmospheric heat flux in the surface energy budget. This increases the temperature variation of the surface forcing the near-surface temperature gradient and thereby the diabatic heat flux to higher values than are typical on the Earth, resulting in turn in a deeper daytime boundary layer. As wind speed is much like that of the Earth, this larger diabatic heat flux is carried mostly by larger maximal values of T*, the surface scale temperature. The higher kinematic viscosity yields a Kolmogorov scale of the order of ten times larger than on Earth, influencing the transition between rough and smooth flow for the same surface features.The scaling laws have been validated analysing the Martian surface-layer data for the relations between the power spectra of wind and temperature turbulence and the corresponding mean values of wind speed and temperature. Usual spectral formulations were used based on the scaling laws ruling the Earth atmospheric surface layer, whereby the Earth's atmosphere is used as a standard for the Martian atmosphere.
Studies of 17-hydroxycorticosteroids in children. II. Response of blood levels to the injection of certain hormones.

Summary 1. The response of 17-hydroxycorticosteroid plasma levels to the administration of ACTH, cortisone, and epinephrine is reported both in well and in sick children. 2. The injection of ACTH causes a prompt but transient elevation of 17-hydroxycorticosteroid levels. Cortisone administered orally likewise causes a prompt and transient elevation of these levels but cortisone administered intramuscularly in a single dose results in a somewhat variable response. 3. The injection of epinephrine results in no consistent pattern of response of 17-hydroxycorticosteroid plasma levels. On the basis of these data the validity of the previously postulated mechanism of action of epinephrine is questioned. 4. The preliminary data concerning responses of 17-hydroxycorticosteroid plasma levels to these three stimulating agents do not show major differences in the groups of children reported here.
Basic factors in the formation and stability of nonsoap lubricating greases: II. The mechanism of gel formation

Abstract High-area hydrophobic and hydrophilic solids flocculate in pure or dry liquids to form grease gels by particle-to-particle contact. In these systems, particle diameter and concentration of thickener are more important in gel formation and resulting consistency than the degree of polarity of the solid surface or of the liquid. When water is present, on the other hand, the formation of structure depends greatly on whether the dispersed solid is hydrophilic or hydrophobic. Trace water markedly influences the flocculation of hydrophilic solids dispersed in polar or nonpolar vehicles; however, trace water has little effect on the flocculation process of hydrophobic thickeners. In nonpolar vehicles, water enhances the flocculating ability of polar solids; in polar vehicles, the opposite effect is found. Heptyl alcohol and amine (and their benzene analogs) drastically thin greases built with polar solids. Heptyl aldehyde, chloride, and acid generally have small influence. As the polarity of the solid is increased, the thinning ability of the additives increases. Distinctly different are carbon black built greases which are not influenced by these additives. Greases built with Estersil, which possess a predominantly but not entirely hydrophobic surface, are affected somewhat differently from the greases made from predominantly polar solids. In the presence of additives and water, the degree of surface polarity determines whether one component (water or additive) will be displaced by increasing concentrations of the second component.
The Evolution of Education and Literacy in Western Civilization

Education and literacy have contributed to how people in Western Civilization communicate and learn about everything in life from the humanities to science and technology. As a result, literacy and education have been the indicators of whether or not a person is “well off” or “disadvantaged” (Kraus, 2000, p. 323). Other civilizations and cultures also value education and literacy because it gives them the new knowledge of people, places, and inventions.
Media Bias, Perspective, and State Repression: The Black Panther Party

Introduction Part I. Conceptualization: 1. Objectivity and subjectivity in event catalogs 2. The Rashomon effect, observation and data generation 3. Understanding state repressive behavior Part II. Cases: 4. The Black Panther Party vs. the United States, 1967-73: background 5. An event catalog of dissent and repression: the BPP in the Bay Area 6. A mosaic of coercion: five cases of anti-Panther repressive behavior Part III. Conclusion: 7. Conclusion: conflict, events and catalogs Appendix 1: The Black Panther-U.S. Government event catalogs.
THE ELECTRIC GUN: A NEW METHOD FOR GENERATING SHOCK PRESSURES IN EXCESS OF 1 TPa

By combining the electrically-driven, flying-plate, high-explosive initiator with well-known gas-gun technology, a novel method of generating and measuring shock pressures greater than 1 TPa has been developed. Called the electric gun, this system is competitive with laser or nuclear-driven, shock-wave, equation-of-state experiments in the 1 to 5 TPa range. Compared to those other methods, it has the advantage of simplicity, high precision, and low cost. In addition, its small size and low total energy allow it to be easily contained for experiments with toxic materials.
Interpretation of solar extinction data for stratospheric aerosols

This paper discusses the inversion problem for aerosols using the solar extinction method. A series of numerical experiments is described in which solar extinction measurement systems are modeled. A numerical model of a solar extinction measurement system has been coupled with model atmospheres that exhibit fine scale structures to produce numerically generated data signals. These signals were then inverted to study the effect that measurement errors and desired vertical resolution produce in the inverted results. Knowledge o2 the trade off between vertical resolution and the accuracy of inversion aid in the interpretation of the inverted results.
A Critique of Renzulli's Theory into Practice Models for Gifted Learners:

In this paper, I offer my views on the theory and practice models of Dr. Joseph Renzulli, a leading researcher and theorist within the field of gifted education. Renzulli's model is critiqued against a set of criteria proposed by the author for a “good” gifted program. There are many strengths to Renzulli's model; but a major weakness is the lack of school-based assessment procedures that can guide decisions about a broader range of accelerative, enrichment, and other types of program options for gifted students with different needs. The major ideas underlying Renzulli's theory were also critically examined, including the broadening of the talent pool, the emphasis on products, and the focus on the development of creative productivity as a basis for educational programs for gifted children.
Steady State and Pulsed Thermal Simulation of Gateless AlGaN/GaN Heterostructures

Due to the complex nature of the failure in reliability of GaN electronics, a multiphysics model was developed to describe the evolution of electrical, thermal, and mechanical stress fields in devices under operational conditions. Electrical, thermal and mechanical characteristics of an AlGaN/GaN transmission line measurement (TLM) structure were modeled under steady state and pulse operational conditions for varying input powers. The electric field and power dissipation in the device was determined by solving Maxwell’s equations while the peak temperature was obtained by solving the thermal energy equation. By coupling the solutions, the impact on device current-voltage characteristics was obtained. Under pulse conditions, devices showed higher currents and lower temperature rises owing to reduced Joule heating compared to steady state. Finally, a one way coupling to a thermo-mechanical model of the device allowed for the analysis of the thermal-induced stress fields which have an impact on the overall device reliability. It was found that the peak temperature and stress in the simulated device at 40 V in steady state was 765 K and −0.60 GPa, while in pulsed mode the peak temperatures and stress were significantly lower at 562 K and −0.38 GPa for a 5 μs pulse and 652 K and −0.48 GPa for a 25 μs pulse.Copyright © 2010 by ASME
Carbohydrate-controlled precipitation of apatite with coprecipitation of organic molecules in human saliva: stabilizing role of polyols.

Addition of common dietary carbohydrates to Millipore-treated human whole saliva either enhances or inhibits the formation of salivary precipitates, some carbohydrates showing no effect. The purpose of this study was to investigate the precipitation conditions more thoroughly and to elucidate the chemical nature of the precipitates formed. D-Xylose either enhanced precipitation (in long-term incubations) or had no appreciable effect (in 10 minute incubations). Other aldo- and ketosugars and disaccharides (maltose, sucrose, lactose) generally enhanced precipitation, whereas all polyols (xylitol, D-sorbitol, mannitol, and maltitol) retarded the formation of turbidity in saliva. Xylitol inhibited formation of precipitates also in the presence of D-xylose, dextrans, and starch. Fast protein liquid chromatography (FPLC) of EDTA-soluble pellets obtained by centrifugation of the precipitates produced two major protein fractions (I and II) with a molecular weight of 112,000 and 46,000, respectively. The carbohydrates exerted a selective effect on the relative size of I and II in that polyol incubations resulted in a I to II ratio of 1∶3, whereas control incubations (without added sugars) and incubations with other carbohydrates gave ratios of 1∶6 to 1∶10. Both peaks contained large amounts of acidic amino acids, proline, and glycine. The saliva precipitates contained a substantial portion of a crystalline phase that had the crystal structure of apatite, the individual crystallites being extremely small (<1 μm) with a Ca∶P ratio of 1.46. The carbohydrates had a similar effect on the overall inorganic composition of the precipitates, but they ahd a clearly selective effect on the rate of formation of precipitates and on the relative amount of coprecipitating salivary proteins. This selectivity indicates that these carbohydrates, when consumed habitually, may exert different effects on the precipitation of Ca-salts at mineral-deficient enamel and dentine sites.
Interactive dynamic force analysis using constraint-based approach

This paper discusses the interactive dynamic force analysis of a planar mechanism using the constraint-based approach. The constraint network provided by the design tool, which includes geometric, dimensional and algebraic constraints, is utilized to impose relations among the skeleton-form mechanism and associated velocity, acceleration and force polygons. The slider-crank mechanism in a reciprocating engine is selected to demonstrate this new approach, with an emphasis on inertia forces and the effect of different mechanism positions on them. When one of links in the mechanism is dragged to produce an input motion, the imposed constraints force all the vector polygons to animate their shapes and sizes in tandem with the animated motion of skeleton mechanism. With such a powerful animation feature, the dynamic force analysis as exhibited in this study proves to be effective. In addition, the design evaluation involving dimension modification can be swiftly performed for any link in the mechanism to study its effect on inertia forces.