cssi/SciSciGPT-SciSciNet huggingface dataset:
PiRNAs Rise to Rescue Koalas

PIWI-interacting small RNAs (piRNAs) establish sequence-specific adaptive restriction of resident genomic parasites to guard genome integrity. In this issue of Cell, Yu, Koppetsch, et al. describe an innate piRNA-response that specifically fragments the viral RNA genome in the germline of recently invaded koalas. This first line of defense might ensure survival until adaptive immunity develops.
Measurements and Discussion of a Balanced Photonic Link Utilizing Dual-Core Optical Fiber

The use of dual-core optical fibers in balanced photonic links is explored. The gain and noise performance improvements are demonstrated. The optical crosstalk is measured as a function of frequency, and the balanced phase tolerance as a function of temperature is discussed.
Teaching and Research on Plasma-Based Green Energy Technologies and Some Associated Environmental and Societal Impacts

Plasma-based green energy technologies and associated environmental and societal impacts are discussed in this paper. The reported work is a portion of integrated research and academic programs established at Boston University for plasma-based technologies, viz., plasma photonics and nanotechnology, plasma medicine, spacecraft propulsion, laser and magnetic plasma fusion as green energy sources, and solar powered systems. Focused for discussions in this paper is our ongoing research work applicable to “plasma fusion energy” and “solar powered systems” because of the public awareness and interest in those subjects. Some potential environmental issues associated with green energy technologies are addressed, to ensure their safe operations to protect our planet. Relevant courses are scheduled in the university curriculum as well as planned as IEEE short courses to broaden the learning of science, technology, engineering and mathematics (STEM) for the public.
The Lure of the New and the Hold of the Dogmatic

In this article, St.Pierre argues that the dualist Cartesian ontology of the human, social, empirical sciences, along with that ontology’s Cartesian cogito and its research methodologies, has produ...
Evaluating the Impact of Mobile Phone Technology on Health Outcomes for Latinos with Type 2 Diabetes

To assess whether a Spanish-language text messaging program helps Latinos with diabetes better manage their disease. Spanish-speaking Latinos with type 2 diabetes and HbA1c ≥ 8% (N = 38) were recruited January 1, 2016–May 31, 2016, at a large integrated healthcare delivery system. Participants received 1–3 Spanish-language text messages about diabetes self-care per day for 3 months with an optional 3-month extension. The Wilcoxon signed-rank test for paired data was used to compare pre-post intervention HbA1c. The Wilcoxon-Mann-Whitney nonparametric test was used to compare changes in HbA1c across groups. After 3 months, the median HbA1c reduction overall was 1.4 percentage points (IQR: 0.5–3.3, p 10.0% had a greater reduction in median HbA1c (3.8, IQR: 0.5–5.3) compared with those having pre-intervention HbA1c ≤ 10.0% (0.9, IQR: 0.1–1.9, p < 0.05). This reduction in median HbA1c persisted after 6 months (1.3, IQR: 0.2–2.9, p < 0.01). A Spanish-language text messaging program was an effective way to improve glycemic control for Latinos with type 2 diabetes. Culturally and linguistically tailored text messaging programs for managing diabetes should be considered.
Utilization by Long-Term Nursing Home Residents Under Accountable Care Organizations.

Abstract Objectives Nursing home care is common and costly. Accountable care organization (ACO) payment models, which have incentives for care that is better coordinated and less reliant on acute settings, have the potential to improve care for this high-cost population. We examined the association between ACO attribution status and utilization and Medicare spending among long-term nursing home residents and hypothesized that attribution of nursing home residents to an ACO will be associated with lower total spending and acute care use. Design Observational propensity-matched study. Setting and Participants Medicare fee-for-service beneficiaries who were long-term nursing home residents residing in areas with ≥5% ACO penetration. Methods ACO attribution and covariates used in propensity matching were measured in 2013 and outcomes were measured in 2014, including hospitalization (total and ambulatory care sensitive conditions), outpatient emergency department visits, and Medicare spending. Results Nearly one-quarter (23.3%) of nursing home residents who survived into 2014 (n = 522,085, 76.1% of 2013 residents) were attributed to an ACO in 2013 in areas with ≥5% ACO penetration. After propensity score matching, ACO-attributed residents had significantly (P Conclusions and Implications ACO nursing home residents had fewer hospitalizations and ED visits, but did not have significantly lower total Medicare spending. Among residents, attribution was not stable year over year.
Systemic evaluation of spatio-temporal variations in travel time reliability due to a toll road over time

This paper evaluates the effectiveness of toll roads in reducing congestion and improving travel time reliability on streets within its vicinity, over time. The data, from the year 2013 to 2017, fo...
The Ocean and Climate Change Law: Exploring the Relationships

Given the close physical interconnections between the ocean and climate change, should the legal regimes governing them be more closely tied? Could climate change law do more to address ocean issues and, if so, in what ways? The chapter argues that, in general, the current division of labor between climate change and ocean law makes sense: the UN climate change regime should focus on mitigating climate change, which is the most important way it can help the ocean; conversely, ocean law is better equipped to address how the ocean might adapt to the impacts of climate change. However, the chapter suggests two ways that a stronger focus by the climate change regime on ocean issues might help it both limit climate change and better protect the ocean. First, it should do more to encourage the conservation and enhancement of ocean sinks, including potentially in areas beyond national jurisdiction, if that proves legally and technically feasible. Second, it should give extra consideration to reducing CO2 emissions relative to other greenhouse gases, given their role in causing ocean acidification.
Accounting Comparability and the Value Relevance of Earnings and Book Value

The value relevance of financial statements is of great significance to investors and standard setters. The present research examines whether accounting comparability among industry peers enhances the value relevance of earnings and book value. This is an important question because both the Financial Accounting Standards Board and the Securities Exchange Commission seek greater comparability in financial reporting. However, there is limited empirical evidence on how comparability affects the value relevance of accounting information in the U.S. Our results show that accounting comparability increases the value relevance of earnings, but not book value. That is, when firms exhibit greater accounting comparability vis-a-vis industry peers, investors attach higher value to reported earnings. In terms of economic significance, the value relevance of earnings is 25.2 percent higher when accounting comparability is higher by one standard deviation. However, the incremental benefits of accounting comparability are attenuated when financial reporting opacity is high or when there exists an internal control material weakness over financial reporting. In contrast, comparability benefits are enhanced when an industry specialist auditor is employed. Our results are robust to using different model specifications.
Obesity and Critical Illness in COVID-19: Respiratory Pathophysiology.

Author(s): Wolf, Molly; Alladina, Jehan; Navarrete-Welton, Allison; Shoults, Benjamin; Brait, Kelsey; Ziehr, David; Malhotra, Atul; Hardin, C Corey; Hibbert, Kathryn A | Abstract: ObjectiveRecent cohort studies have identified obesity as a risk factor for poor outcomes in coronavirus disease 2019 (COVID-19). To further explore the relationship between obesity and critical illness in COVID-19, the association of BMI with baseline demographic and intensive care unit (ICU) parameters, laboratory values, and outcomes in a critically ill patient cohort was examined.MethodsIn this retrospective study, the first 277 consecutive patients admitted to Massachusetts General Hospital ICUs with laboratory-confirmed COVID-19 were examined. BMI class, initial ICU laboratory values, physiologic characteristics including gas exchange and ventilatory mechanics, and ICU interventions as clinically available were measured. Mortality, length of ICU admission, and duration of mechanical ventilation were also measured.ResultsThere was no difference found in respiratory system compliance or oxygenation between patients with and without obesity. Patients without obesity had higher initial ferritin and D-dimer levels than patients with obesity. Standard acute respiratory distress syndrome management, including prone ventilation, was equally distributed between BMI groups. There was no difference found in outcomes between BMI groups, including 30- and 60-day mortality and duration of mechanical ventilation.ConclusionsIn this cohort of critically ill patients with COVID-19, obesity was not associated with meaningful differences in respiratory physiology, inflammatory profile, or clinical outcomes.
Parent Attitudes Toward Enhancing Cognition and Clinical Research Trials in Down Syndrome: A Mixed Methods Study.

OBJECTIVE As understanding of the neurobiological basis of cognitive impairment in Down syndrome (DS) advances and new pharmaceutical interventions targeting neurodevelopment become available, an in-depth understanding of the family perspective is essential to inform research efforts. A mixed methods study was conducted with parents of individuals with DS to learn about attitudes toward pharmacological interventions to enhance cognition, participation in clinical research trials in DS, and the relationship between child/family-specific factors and parent attitudes. METHOD Parents completed an online survey (N = 37) assessing family/child sociodemographic factors and to capture thoughts on cognitive enhancement and participation in clinical drug trials. A subset of interested parents participated in a follow-up phone interview (N = 21) or focus group (N = 3; 1 FG). Double-blind thematic analysis was used to analyze qualitative data. RESULTS Parents' attitudes toward improving cognition, reversing intellectual disability, and participation in clinical trials correlated with each other and were informed by specific parent and child factors (e.g., child attention-deficit hyperactivity disorder/behavioral diagnosis and parent education). Qualitative themes included advantages, disadvantages, and ethical implications of enhancing cognition. In addition, themes emerged regarding the need to understand the mechanism and potential side effects of experimental drugs, logistical factors relating to willingness to participate in clinical trials, and the evolution of parents' attitudes over time. CONCLUSION The findings highlight the complexity of issues and implications of clinical trials for enhancing cognition in DS. Child-specific factors, logistical and safety considerations, and personal belief systems all inform parent attitudes and decision making. The findings reflect the importance of incorporating parent perspectives and values in research direction and design.
Chlorophyll a and non-pigmented biomass are sufficient predictors for estimating light attenuation during cultivation of Dunaliella viridis

Abstract Characterizing light in microalgal cultivation vessels is needed for modeling and optimizing microalgal growth for large-scale cultivation. Dynamic changes in light intensity over space due to geometry, refraction/reflection, and the interactive impacts of algal growth and their biocomponents with light make this characterization challenging. Understanding which biocomponents within microalgal cultures are key variables in accurately estimating light attenuation is fundamentally important, yet, inconsistent and wide-ranging applications of the Beer-Lambert law are often used to estimate light attenuation. This research rigorously evaluated which biocomponents (total biomass, cell count, and chl a, chl b, and total photosynthesizing pigments), or biocomponent combinations, serve as best predictors for light attenuation when modeling with the Beer-Lambert law. Calibration and validation experiments were performed using salt-water species Dunaliella viridis microalgal cultures grown in 3-L flat-plate PBRs with continuous light monitoring. Results at the various light and nitrogen levels tested showed Beer-Lambert's law predicted photosynthetic light attenuation well when both biomass and chlorophyll a were considered as distinct attenuating components, providing light estimates with less than 6% error on average over validation experiments. If the model included only one component as a predictor for attenuation, pigments were best, with a 20% error in estimating light, as compared to ~70%, 60%, 40% for models that used solely biomass, cells, or chlorophyll a as an attenuating component., respectively. These results suggest that when using the Beer-Lambert's law to estimate photosynthetic light attenuation in microalgal cultures, both a chlorophyll a and biomass component should be consistently included.
Moving Towards Proficiency: A Grounded Theory Study of Early Childhood Teacher Candidates and Professional Development Schools

Demands placed on early childhood teacher development, teacher candidates, and professionals who prepare future teachers, continue to increase. Although inquiry addresses high-stakes teacher development, research on programs in early childhood professional development schools as a pathway to mediate the increased demand is needed. The purpose of this study is to develop a framework to evaluate teacher candidate development that is aligned with state measures of teacher effectiveness in a professional development school. Constructivist grounded theory (Charmaz, Constructing grounded theory, Sage, 2014) guided the collection and analysis of forty-three semi-structured interviews. A theoretical framework of three interrelated categories was identified: Engaged Teacher Candidate, Professional Teacher Candidate, and Reflective Teacher Candidate. Even further, seven interrelated sub-categories in the teacher candidates’ development were identified: establish relationships, classroom management, technical aspects of teaching, teacher quality standards, professional dispositions, self-reflection, and goal setting. The overarching framework was named Proficient Teacher Candidate. The framework will be evaluated against a taxonomy of development in relation to a professional development school.
Vortex: Extending the RISC-V ISA for GPGPU and 3D-Graphics

The importance of open-source hardware and software has been increasing. However, despite GPUs being one of the more popular accelerators across various applications, there is very little open-source GPU infrastructure in the public domain. We argue that one of the reasons for the lack of open-source infrastructure for GPUs is rooted in the complexity of their ISA and software stacks. In this work, we first propose an ISA extension to RISC-V that supports GPGPUs and graphics. The main goal of the ISA extension proposal is to minimize the ISA changes so that the corresponding changes to the open-source ecosystem are also minimal, which makes for a sustainable development ecosystem. To demonstrate the feasibility of the minimally extended RISC-V ISA, we implemented the complete software and hardware stacks of Vortex on FPGA. Vortex is a PCIe-based soft GPU that supports OpenCL and OpenGL. Vortex can be used in a variety of applications, including machine learning, graph analytics, and graphics rendering. Vortex can scale up to 32 cores on an Altera Stratix 10 FPGA, delivering a peak performance of 25.6 GFlops at 200 Mhz.
Affinity Purification of a Recombinant Protein Expressed as a Fusion with the Maltose-Binding Protein (MBP) Tag

Expression of fusion proteins such as MBP fusions can be used as a way to improve the solubility of the expressed protein in E. coli (Fox and Waugh, 2003; Nallamsetty et al., 2005; Nallamsetty and Waugh, 2006) and as a way to introduce an affinity purification tag. The protocol that follows was designed by the authors as a first step in the purification of a recombinant protein fused with MBP, using fast protein liquid chromatography (FPLC). Cells should have been thawed, resuspended in binding buffer, and lysed by sonication or microfluidization before mixing with the amylose resin or loading on the column. Slight modifications to this protocol may be made to accommodate both the protein of interest and the availability of equipment.
The Use of Social Networking Sites by Adolescents with Psychiatric Illnesses: A Qualitative Study

Background: Social networking sites (SNSs) are increasingly dominant platforms for communication among adolescents. Recently, concerns have been raised about the risks involved with SNS use, particularly among more vulnerable adolescents. Objective: Our goal was to explore the experience of SNS use by adolescents with psychiatric illnesses. We also sought to understand the ways in which these sites may be a useful way to communicate—as well as a potential source of increased stress—for this vulnerable population. Methods: We performed a qualitative study by conducting in-depth, semi-structured interviews with 20 adolescents (mean age, 16 years; 15 female and 5 male participants) attending the Yale Adolescent Intensive Outpatient Program, which includes 3 hours of outpatient treatment 3 or 4 days per week. Results: The participants in our study described multiple ways in which SNSs possessed unique utility as platforms for communication. Participants found that SNSs allowed them to reach out to a broader audience and to “broadcast” feelings of distress without forcing any specific person into a supportive discussion. In addition, SNSs were described as lower-stress means of communication that allowed responses to be carefully formulated; this led to participants sharing information that they would not have shared during face-to-face interactions. However, participants also described anxiety surrounding the pressure to be active on SNSs, and they found it stressful to be exposed to pictures and posts involving former romantic partners. Conclusion: SNSs provide a useful platform for adolescents with psychiatric illnesses to use to communicate, particularly with regard to communicating any feelings of distress. However, there are many ways in which SNSs can increase levels of anxiety, and this aspect may be an important focus of future clinical attention.
Constitutional Economics of the WTO

This chapter examines the World Trade Organization (WTO) from the social scientific perspective of constitutional economics. This chapter thus seeks to identify the causes and consequences of constitutionalization. Assuming that states act with intentionality and accuracy in their establishment of organizational features, the cause of constitutionalization is the desire to effect the consequences of constitutionalization, so the focus here is on the potential consequences of constitutionalization in and in connection with the WTO.
Impact of the global crisis on the achievement of the MDGs in Latin America

Progress towards the MDGs is expected to slow as a consequence of the global economic downturn. This study uses a dynamic-recursive CGE analysis for six Latin American countries and finds that a projected recession in 2009-2010, followed by a slow and gradual recovery, would put some of the region’s low-income countries substantially further off track towards several of the goals. Extra spending of 1.5 to 2.0 per cent of GDP per year until 2015 would be required to achieve the goals, and this would come on top of another 2 to 7 per cent of GDP per annum of additional spending estimated in absence of the crisis. Additional costs owing to the crisis would stretch government finances should recovery and sustained growth not set in swiftly. At the same time, however, the additional public spending on education, health and water and sanitation is shown to contribute to recovery as part of a counter-cyclical response, which would be stronger if complemented by investments in public infrastructure. For full recovery, however, other factors need to contribute as well, especially the resumption of external demand which in turn would require globally concerted stimulus measures to take effect.
Left ventricular assist device implantation strategies and outcomes

Over the past 15 years, the field of mechanical circulatory support has developed significantly. Currently, there are a multitude of options for both short and long term cardiac support. Choosing the appropriate device for each patient depends on the amount of support needed and the goals of care. This article focuses on long term, implantable devices for both bridge to transplantation and destination therapy indications. Implantation strategies, including the appropriate concomitant surgeries are discussed as well as expected long term outcomes. As device technology continues to improve, long term mechanical circulatory support may become a viable alternative to transplantation.
Poor, Rural Women: Spirituality, Religion, and Wellness Across the Life Span

Researchers have suggested strategies in the spiritual domain for improving wellness. This study explored relationships among spirituality, religiosity, and wellness for poor, rural women in early adulthood, early–middle adulthood, and middle–later adulthood. Implications for evidence-based strategies to improve wellness for poor, rural women across the life span are provided.
A probabilistic screening model for evaluating pyrethroid surface water monitoring data.

Synthetic pyrethroids have been detected in recent California surface water monitoring. Filtration is avoided during sample workup because pyrethroids are extremely hydrophobic, tending to sorb to most surfaces. The resultant analytical pyrethroid concentrations reflect both dissolved pyrethroid and pyrethroid associated with suspended sediment in the water column. Such “whole-water” analytical data are not directly comparable to aquatic acute toxicity effect concentrations measured in laboratory sediment-free water. Consequently, any potential aquatic toxicity risk is indeterminate. In this study a simple probabilistic model was developed to allow a screening-level assessment of pyrethroid whole-water monitoring data. The results suggest that water column toxicity of pyrethroids is possible in California's agriculturally-dominated tributaries, and indicate that additional monitoring to better characterize pyrethroid water-column concentrations are warranted. Model refinement will depend on future work that more firmly establishes the relationship between pyrethroid partitioning and bioavailability, and that addresses the potential influence of dissolved organic carbon on pyrethroid sorption and bioavailability.
Visual-Evoked Response Differentiation of Ischemic Optic Neuritis from the Optic Neuritis of Multiple Sclerosis

Fifteen patients with ischemic optic neuritis studied electrophysiologically had a characteristic change of marked reduction in the amplitude of the visual-evoked response even when loss of vision was moderate. The optic neuritis of multiple sclerosis rarely produced this change. Occasionally, small increases in the latent period of the visual-evoked response were recorded from the patients with ischemic optic neuritis. The optic neuritis of multiple sclerosis usually produced significant increases in the latent period. When the normal nerve was tested in patients with ischemic optic neuritis, the visual evoked response was normal. In patients with optic neuritis of multiple sclerosis, stimulation of the "normal" nerve usually produced an increase in the latent period similar to that seen when the involved nerve was stimulated.
Eye contact while lying during an interview

Male and female subjects were placed into an interview situation with male and female confederates of the experimenter’s. Eye contact measures were taken during the interview. Then, the subjects were instructed to continue the interview but to give untruthful answers. Eye contact measures were again taken. The difference between the eye contact measures while lying and while being truthful served as the major data. The results showed that males gazed longer into the female conderates’ eyes while lying, and the females gazed longer into the male confederates’ eyes while lying.
Patterns of Circulating Luteinizing Hormone and Their Relation to Plasma Progesterone Levels During the Menstrual Cycle of the Rhesus Monkey

Using a specific radioimmunoassay for rhesus monkey luteinizing hormone (LH) the concentration of this hormone in peripheral plasma and its temporal relationship to that of progesterone, as measured by a competitive protein binding assay, are described throughout the menstrual cycle. The preovulatory LH surge, lasting 1–3 days, occurred most frequently on days 10–12 of the cycle with a range of 9–21 days. This variability was limited to the portion of the cycle preceding the LH peak, the remainder being remarkably constant (14–16 days). The increase in plasma progesterone levels did not precede, but followed the LH surge. It is concluded that ovulation in this species occurs within 24 hr after the LH peak and that the patterns of circulating LH and progesterone during the menstrual cycle of the rhesus monkey closely resemble those in the human female. (Endocrinology 87: 453,1970)
In vitro selection of highly modified cyclic peptides that act as tight binding inhibitors.

There is a great demand for the discovery of new therapeutic molecules that combine the high specificity and affinity of biologic drugs with the bioavailability and lower cost of small molecules. Small, natural-product-like peptides hold great promise in bridging this gap; however, access to libraries of these compounds has been a limitation. Since ribosomal peptides may be subjected to in vitro selection techniques, the generation of extremely large libraries (>1013) of highly modified macrocyclic peptides may provide a powerful alternative for the generation and selection of new useful bioactive molecules. Moreover, the incorporation of many non-proteinogenic amino acids into ribosomal peptides in conjunction with macrocyclization should enhance the drug-like features of these libraries. Here we show that mRNA-display, a technique that allows the in vitro selection of peptides, can be applied to the evolution of macrocyclic peptides that contain a majority of unnatural amino acids. We describe the isola...
Curves in Affine and Semi-Euclidean Spaces

In this paper we define centroaffine invariant arc length and curvature functions of a curve in affine n-space. Then we consider the properties and relations of the curves in affine space and Semi-Euclidean space. Using these notions and conclusions, by solving certain differential equations, we give some examples and classifications of the curves in affine 2-space and 3-space.
Optimal design of heterostructure tunnel diode with nonlinear current-voltage characteristic

Abstract Optimal design applied to an Al ξ Ga 1 − ξ As heterostructure tunnel diode is used to achieve a parametrically defined nonlinear current–voltage characteristic. The design predicts that a significant reduction in spurious frequency components from a switching RF mixer can be realized using a device that is less than 17 nm thick.
Tomato growth, nitrogen fraction and mineral composition in response to nitrate and ammonium foliar sprays 1

Abstract Tomato plants were grown in sand culture with NO3 or NH4 N at two levels of light. Foliar sprays at three levels of N as well as combinations of foliar and root feeding were used. Shade increased NH4 toxicity in plants sprayed with NH4 but decreased the toxicity in plants receiving NH4 through the roots. NH4‐N greatly reduced growth and cation uptake when supplied through the roots but not with foliar application. Plants sprayed with NH4 showed better growth, higher K, Ca, and Mg content and lower free NH4 in shoot, compared to plants receiving NH4 through the roots. The overall free amino acid contents of shoots was higher for NH4‐fed plants regardless of how the N was applied. Plants sprayed with NH4 incorporated a greater amount of N into insoluble compounds compared with NO3 nutrition. The N uptake per unit of leaf area was higher for plants grown under full sun light whereas N content was higher for plants grown under hade. N content in tissue increased with N concentration in foliar spray, ...
Density of comet Shoemaker–Levy 9 deduced by modelling breakup of the parent 'rubble pile'

FOR a week beginning 16 July 1994, fragments of comet Shoemaker-Levy 9 will collide with Jupiter each day. Although the fragments are probably smaller than originally estimated1, the impacts may nevertheless have observable consequences that will provide valuable insight into the properties of comets and the dynamics of planetary atmospheres. Interpretation of these observations will depend sensitively on parameters such as the mass, density and overall structure of the fragments. To deduce some of these parameters, we have simulated the event that created the fragments—the passage of the parent comet through the tidal field of Jupiter in 1992. Modelling the comet as a strengthless aggregate consisting of a large number of grains, we find that the tidally disrupted body condenses rapidly into clumps, driven by their selfgravity. Formation of a fragment chain resembling Shoemaker-Levy 9 occurs for a narrow range of the simulated comet's bulk density, 0.3–0.7 g cm −3. A chain of ∼20 similar-sized fragments matching observations is obtained for a non-rotating parent comet of 1.5 km diameter and bulk density 0.5 g cm−3, suggesting that the clusters will each liberate ∼1027 erg on impact. A slightly larger initial density leads to significant mass variation among the clusters and the possibility of a few ∼1028-erg events.
SINUS ARREST INDUCED BY TRIVIAL NASAL STIMULATION DURING ALFENTANIL-NITROUS OXIDE ANAESTHESIA

A case is reported of bradycardia and sinus arrest induced by insertion of a nasal temperature probe. Other possible causes of bradycardia and sinus arrest under anaesthesia are reviewed briefly. Evidence for the neurological basis of a nasocardiac reflex, similar to the oculocardiac reflex, is presented. A minor, trivial stimulus may elicit this reflex.
Chapter 2 Lipid metabolism in procrayotes

Publisher Summary This chapter provides an overview of the regulatory mechanisms of lipid metabolism in prokaryotes. The main advantage that bacteria offer over other systems is the use of the genetic approach to manipulate the experimental system. In E. coli, phospholipids are synthesized exclusively for use in the biogenesis of membranes, and there does not appear to be any significant alternative fate for these lipids. The chapter indicates that the mechanisms that operate to produce the observed distribution of phospholipid polar head groups have not been uncovered, and the details of how phospholipid and macromolecular biosynthesis are coordinated during normal growth and nutritional stress remain to be established. The regulatory point that controls the divergence of 20% of the acyl-acyl-carrier protein (ACP) to lipid A biosynthesis rather than to phospholipid production is also a mystery. The genetic approach will continue to be an important tool for this, and recent advances in genetic-cloning procedures have begun to have a profound effect on the understanding of both the biochemistry and physiology of E.coli.
Manufacturing considerations for implementation of scatterometry for process monitoring

The continuing demand for higher frequency microprocessors and larger memory arrays has led to decreasing device dimensions and smaller process control windows. Decreasing process control windows have created a need for higher precision metrology to maintain an acceptable precision to tolerance ratio with a reasonable sampling rate. In order to determine and reduce across chip, across wafer, and across lot linewidth variations, higher sampling is required which, in turn, demands faster move acquire measure (MAM) times to maintain throughput. Finally, the need to detect and quantify sidewall angle changes in addition to CD measurements is becoming critical. Spectroscopic Scatterometry is a metrology technique which offers the potential to meet these requirements. This work explores some of the fundamental technology concerns for implementing scatterometry in a manufacturing environment. These concerns include mark requirements and characterization necessary for library generation. Comparison of scatterometry data to in-line CD SEM, x-section SEM, and AFM results will be presented.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The role of endothelial nitric oxide synthase in the pathogenesis of a rat model of hepatopulmonary syndrome.

Abstract BACKGROUND & AIMS: The hepatopulmonary syndrome occurs when intrapulmonary vasodilatation causes impaired arterial gas exchange in liver disease. The pathogenesis is poorly understood, although nitric oxide may be involved. Common bile duct ligation in the rat is a model of the hepatopulmonary syndrome, but no studies have evaluated NO in pulmonary vasodilatation in this model. The aim of this study was to determine whether NO contributes to intrapulmonary vasodilatation after bile duct ligation. METHODS: Endothelial and inducible NO synthase (NOS) levels and localization and NO activity in pulmonary artery rings were assessed after bile duct ligation. RESULTS: Pulmonary endothelial NOS levels increased and alveolar vascular staining was enhanced after bile duct ligation. No change in pulmonary inducible NOS levels or localization was detected. Increased endothelial NOS levels correlated with alterations in gas exchange and were accompanied by enhanced NO activity and a blunted response to phenylephrine, reversible by NOS inhibition, in pulmonary artery rings. Portal-vein-ligated animals, which do not develop intrapulmonary vasodilatation, had no changes in pulmonary NOS production or in NO activity in pulmonary artery rings. CONCLUSIONS: NO, derived from pulmonary vascular endothelial NOS, contributes to intrapulmonary vasodilation in animal hepatopulmonary syndrome. (Gastroenterology 1997 Aug;113(2):606-14)
Magnetic Resonance Characterization of the Peri-Infarction Zone of Reperfused Myocardial Infarction With Necrosis-Specific and Extracellular Nonspecific Contrast Media

Background—Because ischemically injured myocardium is frequently composed of viable and nonviable portions, a method to discriminate the two is useful for clinical management. Methods and Results—Ischemically injured myocardium was characterized with extracellular nonspecific (Gd-DTPA) and necrosis-specific (mesoporphyrin) MR contrast media in rats. Relaxation rates (R1) were measured on day 1 and day 2 by inversion-recovery echoplanar imaging. Spin-echo imaging was used to define contrast-enhanced regions and regional wall thickening. Gadolinium concentration, area at risk, and infarct size were measured at postmortem examination. ΔR1 ratio (ΔR1myocardium/ΔR1blood) after administration of Gd-DTPA was greater in ischemically injured myocardium (1.20±0.15) than in normal myocardium (0.47±0.05, P<0.05), which was attributed to differences in gadolinium concentration and water content. The Gd-DTPA–enhanced region on day 2 was larger (32.8±0.9%) than true infarction as demonstrated by triphenyltetrazolium chl...
Heat-sensitive development of the phagocytotic organelle in a Tetrahymena mutant.

Abstract A laboratory-induced mutant with heat-sensitive development of the phagocytotic organelle has been isolated in Tetrahymena pyriformis , syngen 1; the mutant cells form food vacuoles at 30 °C, but not after incubation at 37 °C. Mutant cells transferred to 37 °C undergo a maximum of 3–5 doublings, but a sizeable fraction remains viable for several days. Results of temperature shift-up experiments reveal that an oral apparatus (OA) constructed at 30 °C remains functional at 37 °C, while one constructed at 37 °C is non-functional with regard to phagocytosis. Preliminary cytological observations reveal severe structural abnormalities of the OA. Thus the mutant appears to be primarily affected in the morphogenesis of the OA. The phenotypic effect of the mutation is reversible by a temperature shiftdown. Changes in phenotype caused by temperature shifts in either direction can occur even in stationary or starved cultures. Cell division is not required for the resumption of phagocytosis after a temperature shiftdown. Null-formers obtained at the first doubling after a temperature shift-up can divide at least once more, indicating that a functional OA is not required for cell division at any stage of the cell cycle. Mutants defective in phagocytosis may prove useful in gaining deeper understanding of this mechanism and its relationship to other cellular processes.
Reconnection of vorticity lines and magnetic lines

Magnetic field and fluid vorticity share many features. First, as divergence‐free vector fields they are conveniently visualized in terms of their field lines, curves that are everywhere tangent to the field. The lines indicate direction and their density indicates field strength. The question arises of the extent to which the evolution of the fields can be treated in terms of the evolution of their field lines. The essential answer has been given by Newcomb [Ann. Phys. (NY) 3, 347 (1958)]. He derived the general conditions on the evolution of vector fields that permit the identification of field lines from one instant to the next. The equations of evolution of the vorticity field and the magnetic field fall within Newcomb’s analysis. The dynamics of the flows differs between these two systems, so that geometrically similar phenomena happen in different ways in the two systems. This provides opportunity for comparison and contrast. In this paper the geometrical similarities are emphasized. Reconnection will be defined here as evolution in which it is not possible to preserve the global identification of some field lines. There is a close relation between reconnection and the topology of the vector field lines. Nontrivial topology occurs where the field has null points or there are field lines that are closed loops.
Dietary supplementation with orotate and uracil increases adaptive growth of jejunal mucosa after massive small bowel resection in rats.

Background Massive small-bowel resection (SBR) increases adaptive growth of residual intestine in animal models of short-bowel syndrome (SBS). Pyrimidine nucleotides are critical for DNA and RNA synthesis, but no previous study has evaluated whether supplementation of pyrimidines or their precursors in the diet enhances adaptive gut growth after SBR. This study determined growth responses in jejunal mucosa after 7 days of dietary supplementation with uracil, or its precursor, orotate, after massive SBR in rats. Methods Sprague-Dawley rats ( approximately 200 g) underwent 80% jejunoileal resection (RX) or ileal transection (TX; control). Rats were pair-fed a purified (AIN-93G) powdered diet supplemented with or without 1% (wt/wt) orotate or uracil until killing at 7 days postsurgery. Defined jejunal segments were obtained for analysis of mucosal villus height (VH), crypt depth (CD), total mucosal height, bromodeoxyuridine (BrdU) incorporation, an index of cell proliferation, and full-thickness DNA and protein content as measures of intestinal adaptive growth. Results Jejunal VH increased significantly with SBR, as expected, and orotate further stimulated this response. Jejunal CD and total mucosal height increased significantly with both orotate and uracil supplementation compared with resected animals receiving standard diet. Orotate administration also increased jejunal DNA content compared with the increase observed with SBR alone. Finally, orotate, but not uracil, supplementation increased BrdU incorporation compared with resected rats fed standard or uracil-supplemented diet after SBR. Conclusions Supplementation of oral diet with the pyrimidine precursor orotate and uracil stimulated adaptive jejunal growth after massive SBR in rats. Dietary orotate had more potent growth-stimulatory effects than uracil in this animal model. Dietary supplementation with orotate and uracil represents a novel nutrition approach to enhance small-bowel mucosal adaptive growth and absorptive capacity in SBS.
Complement in glomerulonephritis.

Decades after the first report of a complement-activating factor in the serum of some people with chronic glomerulonephritis, its causal role in the disease is still debated. In a new study, mice engineered to lack a regulatory protein, factor H, uniformly develop glomerulonephritis, and have ongoing consumption of serum complement similar to that seen in humans.
Running elicited by hypothalamic stimulation

Electrical stimulation of the posterior hypothalamus elicited wheel running in rats. The speed of running was directly related to the intensity of the electrical stimulus. Results suggest that hypothalamic mechanisms mediate locomotor behavior.
Is Trypanosoma cruzi a new threat to our blood supply

Excerpt Chagas disease (American trypanosomiasis), a zoonosis caused by the protozoan parasite,Trypanosoma cruzi(1-3), is a typical "exotic" disease in that it is a major cause of morbidity and dea...
ENDOCRINE FACTORS INFLUENCING TUMOR DEVELOPMENT, THE EFFECT OF THE GONADOTROPINS AND OF THEEL1N UPON THE MARSH-BUFFALO ADENOCARCINOMA AND LYMPHQSARCOMA1

IT IS GENERALLY CONCEDED that the mammary gland adenocarcinoma which occurs spontaneously in a number of strains of mice can occur only in a gland which has undergone a certain degree of development (1). This development is dependent upon the hormones of the ovary and pituitary and possibly adrenals. The explanation of the mechanism is still controversial, there being two theories: a), that the hormones or their products of metabolism have a direct carcinogenic effect; or b), that the hormones merely produce the anatomical development of the gland and n i so doing give the opportunity for a mutation in the multiplying cells, leading to the production of carcinoma. We previously pointed out that in experiments recorded so far the estrogenic hormones used to promote enhanced or early cancer formation have always been of exogenous origin (2). In order to study the effect of endogenous estrin-like substances, prolan was administered parenterally so as to stimulate the ovaries of mice of the Marsh-Buffalo stra...
Transient analysis of electro-osmotic transport by a reduced-order modelling approach

Transient behaviour of electro-osmotic transport in typical electrokinetic channels is studied in this paper. The time needed for the electro-osmotic flow to reach steady-state exhibits multiple time scales depending on whether the flow is governed by either a viscous force, electrokinetic force or by a combination of both. When an intersection is present in the electrokinetic channel, such as in a cross or a T-channel, the flow in the main channel and in the intersection gets to steady-state at different times. A weighted Karhunen–Loeve (KL) decomposition method is proposed in this paper to generate the global basis function for reduced-order simulation. The key idea in a weighted KL approach is that, instead of minimizing a least-squares measure of ‘error’ between the linear subspace spanned by the basis functions and the observation space, we minimize the weighted ‘error’ between the two spaces. The global basis functions in a weighted KL approach can be generated by computing the singular value decomposition (SVD) of the matrix containing the weighted snapshots. We show that the weighted KL decomposition based reduced-order model is computationally more efficient and can capture the multiple time scales encountered in electro-osmotic transport much more effectively compared to the classical KL decomposition based reduced-order model. Copyright © 2003 John Wiley & Sons, Ltd.
Behavioral components of impulsivity predict alcohol consumption in adults with ADHD and healthy controls.

Background The degree to which distinct behavioral components of impulsivity predict alcohol consumption is as yet not well-understood. Further, the possibility that this relation might be more pronounced in groups characterized by heightened impulsivity (i.e., individuals with ADHD) has not been tested.
Seawater desalination using Dewvaporation technique: theoretical development and design evolution

Abstract Dewvaporation is a relatively new technique for seawater desalination. This technique uses air as a carrier gas to evaporate liquid from a saline solution, using cross flow configuration, at atmospheric pressure. A mathematical model was developed which related the production density (kg/h.m2) to the energy reuse factor. However, an approximate solution was established that could be used instead of the rigorous model to predict the energy reuse factor at a given production density. The cross flow was also modeled to evaluate the effect of such flow on the energy reuse factor. It was concluded that with passes greater than 15, the cross flow effect was negligible. Mylar, polypropylene, and twin wall plastic materials were used in studying the Dewvaporation technique. Different designs were constructed and tested which varied from counter flow to cross flow with spacers and without spacers on the evaporation and/or dewformation sides. Different attempts were made to maintain air streams balanced on either side of the heat transfer wall to obtain the maximum heat transfer area. The final design included cross flow with twin wall polypropylene plastics and spacers on the evaporation side only.
Hemodynamic Theory of Progressive Renal Disease: A 10-Year Update in Brief Review

Experimental studies have suggested that glomerular hypertension is ultimately damaging to the kidney. Prevention of glomerular hypertension by dietary protein restriction or antihypertensive therapy lessens glomerular injury in several experimental models of chronic renal disease. Glomerular hypertension and hyperfiltration also occur in humans with diabetes mellitus, solitary or remnant kidneys, and various forms of acquired renal disease. Clinical studies are beginning to show that dietary protein restriction and antihypertensive therapy may slow progression in these disorders. Large multicenter trials are currently under way to better define the effects of these therapeutic maneuvers on the progression of chronic renal disease.