cssi/SciSciGPT-SciSciNet huggingface dataset:
Virtual World Consumer Behavior

This research will look at consumer behaviors in Virtual Worlds (VW) in order to fill the research gap and build a model to explain why users chose to purchase in VWs. Results from this study will help Information Systems (IS) researchers and game developers understand specific user attributes that may affect their intentions to purchase. With this knowledge IS researchers and developers may have the opportunity to manipulate system components in ways to improve business processes and stimulate profits for businesses. This study will rely on the Theory of Reasoned Action (TRA), Flow Theory and the concept of desire for uniqueness (DFU). The study's data will come from online survey volunteer VW users in one region of the United States testing both the model's measurement tool and hypotheses with Structural Equation Modeling (SEM) with Partial Least Squares (PLS). The validity and reliability and the strength and polarity relationships between the variables (user skill, challenge and DFU; VW shopping attitude, subjective norms (SN); and VW purchase intentions) will be assessed. With the results of the study, suggestions for further research will be made.
Imaging and Creating Alternative Environments with Children

The Children Creating Alternative Futures project began in 1981 when a group of us with diverse professional experience, technical skills, and academic backgrounds initiated an environmentally focused, action-research process for children.
Issues in the Structural Reform of Chinese Agriculture1

Publisher Summary This chapter focuses on the issues in the structural reform of Chinese agriculture. In the long run, because of Engel's Law, Chinese agriculture—excluding nonfarm activities—should be targeted at nearly 5% real growth per year to induce rapid development of nonfarm activities, which in turn can absorb surplus labor and generate new sources of rural income. This requires emphasis on quality improvement and a quest for new market opportunities to resolve demand limitations; quantitative growth also requires emphasis on the livestock sector and its growing demand for feed. However, without improved incentives, such a growth rate cannot be sustained for the want of sufficient investment and managerial interest. Continuing administrative control, particularly over grain procurements, and official underpricing of grain and oilseeds, because of the political difficulty of passing further price increases through to urban consumers, threatens the agricultural incentives. If price increases were largely offset by increased rural taxes or land use fees, then there venues could be used to compensate urban consumers for retail price increases.
Pathologic Features of Primary Pancreatic Malignancies

This chapter explores the pathologic features of benign and malignant lesions of the pancreas. As pathologic classifications evolve, particularly for cystic lesions and neuroendocrine tumors, it is important for physicians who treat patients with pancreatic neoplasms to fully evaluate these pathologic classifications.
Social Media in Disaster Relief

As social media has become more integrated into peoples’ daily lives, its users have begun turning to it in times of distress. People use Twitter, Facebook, YouTube, and other social media platforms to broadcast their needs, propagate rumors and news, and stay abreast of evolving crisis situations. Disaster relief organizations have begun to craft their efforts around pulling data about where aid is needed from social media and broadcasting their own needs and perceptions of the situation. They have begun deploying new software platforms to better analyze incoming data from social media, as well as to deploy new technologies to specifically harvest messages from disaster situations.
CHAPTER 20 – Structural Basis of Signaling Events Involving Fibrinogen and Fibrin

Fibrinogen is an extracellular protein found in significant concentrations in the blood plasmas of all vertebrate animals. It is a large, multi-domained protein, some portions of which share common ancestry with lectins and other cytotactic proteins found throughout the animal kingdom. Although the principal role of fibrinogen has to do with its polymerization into fibrin clots, the protein also interacts with a number of other extracellular proteins, blood platelets, and a variety of cells. Directly or indirectly, the fibrinogen-fibrin system is involved in hemostasis, inflammation, wound healing, and angiogenesis. Fibrinogen also interacts with various bacteria, especially certain strains of Staphylococcus. Over the years, there have been numerous reports describing regions of fibrinogen or fibrin responsible for binding various macromolecules or cells. The availability of X-ray structures now provides a backdrop for visualizing some of these at atomic resolution. Among the cells and particles known to bind fibrin(ogen) are platelets, endothelial cells, monocytes, lymphocytes, neutrophils, and fibroblasts, all of which are actively involved in hemostasis, wound healing, inflammation, or angiogenesis. For the most part, studies have utilized fragments of fibrin(ogen), antibodies directed against localized features, site-directed mutagenesis of recombinant fibrinogens, or synthetic peptides corresponding to specific regions.
Arthopor 2 Acetabular Component With Screw Fixation in Primary Hip Arthroplasty A 7- to 9-Year Follow-up Study

Abstract The first 100 consecutive primary hip arthroplasties with the Arthopor 2 acetabular component (Joint Medical Products, Stamford, CT) with supplemental screw fixation performed by the senior author were prospectively studied. The mean patient age was 57 years. Seventy-seven cemented and 23 cementless stems were placed, with 32-mm femoral heads used in most of the patients. Eighty-six hips were reviewed at 7–8.8 years (mean, 7.8 years). The mean Harris hip score at final follow-up evaluation was 94 points. No cups have been revised, although 2 cups in patients with radiation osteonecrosis were loose radiographically. One patient underwent revision of a severely worn liner. Despite a relatively high mean linear wear rate of 0.27 mm/y (range, 0.13–0.57 mm/y), no radiographic evidence of pelvic osteolysis was seen. The Arthopor 2 cup performed well with respect to pelvic osteolysis, despite the presence of substantial polyethylene debris. The relatively high polyethylene wear rate is attributed in part to the younger patient population and the use of 32-mm femoral heads paired with thin polyethylene liners.
Semiparametric Estimation of Longitudinal Medical Cost Trajectory

AbstractEstimating the average monthly medical costs from disease diagnosis to a terminal event such as death for an incident cohort of patients is a topic of immense interest to researchers in health policy and health economics because patterns of average monthly costs over time reveal how medical costs vary across phases of care. The statistical challenges to estimating monthly medical costs longitudinally are multifold; the longitudinal cost trajectory (formed by plotting the average monthly costs from diagnosis to the terminal event) is likely to be nonlinear, with its shape depending on the time of the terminal event, which can be subject to right censoring. The goal of this paper is to tackle this statistically challenging topic by estimating the conditional mean cost at any month t given the time of the terminal event s. The longitudinal cost trajectories with different terminal event times form a bivariate surface of t and s, under the constraint t ≤ s. We propose to estimate this surface using bi...
Population survey and management strategies of free-roaming dogs (Canis familiaris) on Saipan, Commonwealth of the Northern Mariana Islands

The island of Saipan, Commonwealth of the Northern Mariana Islands, is populated by free-roaming dogs who were introduced during World War II. The local nonhuman animal control agency manages this population; however, the demographic information and public perception of this population remain unknown. To characterize the free-roaming dog population, an island-wide survey on Saipan was conducted. Photographic, mark-recapture data were used to estimate the population size per land type. Age, sex, sociality, and behavior per land type were documented and associations between these variables were tested using G tests. The effects of land type and urbanization on dog abundance were also analyzed. Lastly, in-person surveys provided data on the public perception of free-roaming dogs. Four main findings are reported: (a) The population size of free-roaming dogs on Saipan is estimated at 21,316. (b) Most dogs encountered were sentry adults. (c) Dog abundance increased with urbanization level and was highest in urban areas. (d) The public perceived free-roaming dogs as a health concern and suggested the implementation of leash laws and sheltering initiatives. This article discusses potential and existing population management strategies for free-roaming dogs on Saipan.
Accessibility drives species exposure to recreation in a fragmented urban reserve network

Abstract Outdoor recreation is a valuable ecosystem service permitted in most protected areas globally. Land-use planners and managers are often responsible for providing access to natural areas for recreation while avoiding environmental impacts such as declines of threatened species. Since recreation can have harmful effects on biodiversity, reliable information about protected-area visitation patterns is vital for managers. Our goal was to quantify recreational use in a fragmented urban reserve network and identify factors that influenced visitation. We empirically measured visitation rates at 18 reserves in San Diego County, California. Using random forest models, we identified biophysical and socioeconomic factors that influenced spatial variation in visitation rates and made projections to 27 additional reserves, validating with an expert opinion survey. Visitation rates varied widely across the reserve network. Accessibility variables, such as numbers of housing units and parking lots, were key explanatory variables that had positive relationships with visitation rates. To illustrate the applications of our models, we assessed the exposure of 7 species and subspecies of conservation concern to recreation by comparing predicted occurrence to projected visitation intensities. We found that several species and subspecies, including the orange-throated whiptail (Aspidoscelis hyperythra), western spadefoot (Spea hammondii), and the federally-threatened coastal California gnatcatcher (Polioptila californica californica), are likely exposed to high levels of recreational activity. Our results can be used to identify species for further research, highlight areas with potential conflict between recreation and conservation objectives, and forecast future changes in visitation.
Nonbonded Interatomic Potential Functions and Crystal Structure: Non Hydrogen-Bonded Organic Molecules

Nonbonded interatomic potential energies are responsible in large part for the packing of solids and of highly organized macromolecules, such as enzymes, in solution. Considerable effort is being devoted to apply this principle to crystal structures of synthetic polymers1–3 and the conformation of proteins.5,6 With this application in mind, we have analyzed known crystal structures to determine those potential functions which are in best agreement with the packing of molecules in crystals.7,8
Microbial production of flavonoids and terpenoids

Abstract: Flavonoids and terpenoids are two classes of natural products that are currently used as food ingredients, natural food colorants, nutraceuticals and pharmaceuticals. The chapter provides an overview of these two classes of compounds, their biosynthetic pathways, significance in human health and the importance of microbial production. It then discusses strategies for optimizing production in microorganisms, including host selection, redirection of carbon flux, protein engineering and production of non-natural analogs.
Genetic Algorithms for Optimization of Composite Laminates

The design of composite laminates is a combinatorial problem well suited for solution via genetic algorithms. However, the number of analyses required for genetic optimization of even single laminates may be many thousands. Consequently, it is important to tailor standard genetic algorithms to the special problems associated with composite laminates. Two examples are used to demonstrate the importance of specialized codings and operators for the efficiency of genetic optimization of composite laminates. An unstiffened panel example demonstrates the usefulness of repair for handling constraints. A stiffened panel example shows the usefulness of specialized mutation operators.
Path-Referenced Assessment of Individual Differences

Assessment plays a critical role in meeting instructional needs related to individual differences in student competence. Assessment devices have long been central in determining the educational placement of students with special learning needs. Assessment techniques have also been used to diagnose individual learning problems and to place students in curriculum sequences (Glaser & Nitko, 1971).
Disaster recovery steps to maintain and improve urban forest resilience

Considerable research demonstrates the broad range of ecosystem services (i.e., benefits) attributed to urban trees either individually or in groups as part of parks, natural areas, riparian buffers, in green stormwater infrastructure, along streets, and in other urban public landscapes. Environmental services contributed by urban trees include stormwater management, carbon sequestration, and impacts on human health that include air quality and lower urban temperatures (urban heat island mitigation). Communities that adopt arboricultural standards and practices and implement comprehensive urban forest management can provide the longterm outlook needed to manage and maintain these environmental services. One component of this management is disaster response and recovery and this chapter will look specifically at a disaster response/recovery protocol that helps communities maintain viable and valuable urban tree canopy following destructive storm events. The objective of this chapter is to introduce disaster planning, preparedness, response, and recovery utilizing professional arborists and urban foresters as a component of a comprehensively managed urban forest (i.e., community stewardship). It is intended to provide community groups, nongovernmental organizations, civic leaders, and state and federal land and program managers with background on the Urban Forest Strike Team (UFST) disaster response and recovery program.
Multiple Stakeholders' Perspectives Regarding Barriers to Hospice Enrollment in Diverse Patient Populations: A Qualitative Study.

Abstract Context Although studies show disparities in hospice care utilization, many questions remain regarding the causes of these disparities. Most studies focus on a single ethnic/racial group, and most use physician informants. None compare and contrast views of multiple stakeholders or use a systems approach within a single geographic region. Objectives To gain an in-depth understanding of causes of hospice enrollment disparities in diverse patient populations within one state in the U.S. Methods We conducted in-depth, individual interviews with multiple stakeholders in hospice care for diverse communities in Rhode Island. We identified participants through purposeful and snowball sampling strategies, aiming for a maximum variation sample. Interviews were audio-recorded, transcribed verbatim, and analyzed using a multistep grounded theory approach. Results Participants, self-identifying from a wide variety of ethnic backgrounds, included physicians, nurses, social workers, chaplains, nursing assistants, administrators, and caregivers. Five themes emerged regarding patient- and provider-level barriers to hospice enrollment: 1) universal challenges of goals of care (GOC) conversations; 2) cultural norms and beliefs; 3) language barriers; 4) provider-specific challenges; and 5) trust. In minority populations, the central theme of GOC conversation challenges was intensified by the other four themes. Suggested solutions included 1) increased palliative care training; 2) “cultural interpreters” from local communities; 3) specially trained “GOC language interpreters”; 4) improved workforce diversity; and 5) community-level advocacy. Conclusion The disparity in hospice enrollment among diverse patient populations is a complex and nuanced problem, involving numerous interrelated barriers. Addressing this disparity will require innovative solutions at multiple levels.
The other side of an airport’s two-sided market: issues in planning and pricing airport surface access

The first part of the paper considers the two-sided nature of airport platforms, and argues that on the land-side, analysis and policy has generally over-stated the items that should be included. In this context, the paper’s focus is on airport access and how it should be embraced, along with airside considerations, in a two-sided framework when establishing prices and investment. In the second part, the more theoretical argument is juxta positioned with prior empirical analysis of landside access which has largely been treated in a rather ad hoc way, usually implicitly assuming it involves a one-sided market. The subsequent arguments of what needs to be done, are suggestive rather than specific given the diverse institutional and physical nature of airports and their surroundings.
High-speed and High-dynamic Variable Frequency Drive Using Modular Multilevel Converter and SiC Devices

This paper presents a high-speed and high-dynamic variable frequency drive (VFD) based on the modular multilevel converter (MMC) and silicon carbide (SiC) devices. A compact submodule design with the straightforward extension feature is introduced. An integrated control scheme including the low- and high- speed control is developed. Based on the designed prototype and the advanced control scheme, the dynamic response including speed acceleration and torque step-change capabilities are investigated. Besides, the steady-state performance in the high-speed range is also examined in terms of speed control accuracy and current distortion. Validated by the experimental results, the developed VFD prototype with the proposed control scheme can successfully reach the high speed (6000 rpm). It has accurate speed control (±1%) and low current distortion (THD%=2.54%) in high-speed operation, as well as the robust dynamic response.
Dietary Trace Minerals

Dietary trace minerals are pivotal and hold a key role in numerous metabolic processes. Trace mineral deficiencies (except for iodine, iron, and zinc) do not often develop spontaneously in adults on ordinary diets; infants are more vulnerable because their growth is rapid and intake varies. Trace mineral imbalances can result from hereditary disorders (e.g., hemochromatosis, Wilson disease), kidney dialysis, parenteral nutrition, restrictive diets prescribed for people with inborn errors of metabolism, or various popular diet plans. The Special Issue “Dietary Trace Minerals” comprised 13 peer-reviewed papers on the most recent evidence regarding the dietary intake of trace minerals, as well as their effect toward the prevention and treatment of non-communicable diseases. Original contributions and literature reviews further demonstrated the crucial and central part that dietary trace minerals play in human health and development. This editorial provides a brief and concise overview that addresses and summarizes the content of the Dietary Trace Minerals Special Issue.
“Wearing Vintage with a Shaved Head”: Balancing Historic Authenticity with Personal Authenticity in Retro Sewing

Retro sewers, who sew their own versions of historic styles to wear as part of their everyday lives, represent a unique intersection between the vintage clothing market and the home sewing market. For the retro sewers interviewed, although their clothing is historically influenced, much of their style tends to be a negotiation between historic authenticity and personal authenticity, with one often being set against the other. Similar to people who wear vintage clothing, retro sewers are situated at different points on a continuum from a modern look with subtle retro elements to head-to-toe period ensembles. Although both historic authenticity and personal authenticity are important to the participants to at least some degree, typically either one or the other is given priority. This study found that retro clothing is a fusion of historic authenticity with personal authenticity, with one or the other being assigned higher priority depending on the sewer’s preferences and/or the event for which the ensemble is being worn.
Gap Junctions in the Nervous System

Gap junctions in the nervous system fulfill vital functions of signal transmission and metabolite delivery and buffering. Between neurons, gap junctions form electrotonic synapses providing rapid bidirectional relay that is essential for rapid and synchronous activities. Between glial cells, gap junctions provide a route for long-range intercellular calcium signaling, as well as delivery of glucose and buffering of potassium ions. A family of connexin proteins comprises gap junctions with cell-specific expression, and mutations in the genes that encode connexins are responsible for a number of neurological diseases including the X-linked form of Charcot–Marie–Tooth disease, hereditary nonsyndromic deafness, and oculodentodigital dysplasia.
Water arsenic, fluoride and chloride detection capability assessment of the drinking water monitoring Labs in Guangdong province

Objective To assess the proficiency of water monitoring laboratory at rural, county, and provincial levels in Guangdong province, to ensure the province's drinking water monitoring results accurate and reliable. Methods State quality of certified reference materials as water arsenic, fluoride and chloride of 90 copies each were numbered and distributed to 90 monitoring laboratories in the province for testing, The measurement results of the participatory labs were evaluated through normative values and expanded uncertainty, and were compared with those of robust statistics method. Results All participatory labs had timely feedback of their measurement results. The qualified rate was higher when arsenic was tested by hydride generation atomic fluorescence spectrometry and zinc-new silver salt of sulfuric acid spectrophotometric system, while fluoride and chloride by ion chromatography. The average qualified rates of water arsenic, fluoride and chloride of the province's rural drinking water quality monitoring laboratory were 66% (59/90), 72% (65/90) and 72% (65/90), respectively.Seven participatory labs failed the proficiency testing of all three analytes and unqualified rate was 7.8% (7/90)among the ninety participated monitoring labs. The qualified rates of robust statistics method for arsenic fluoride and chloride were greater than those evaluated by the expanded uncertainty, and large deviations with small sample sizes. Conclusions The testing ability of drink-water monitoring labs in Guangdong province has improved.However, by comparison with the requirements of national quality control and testing skills, there is still a gap. It is suggested that internal quality control be included in routine inspeetion to improve laboratory testing technology. Key words: Drinking; Quality control ; Arsenates; Fluorides; Chlorides
Realised volatility and parametric estimation of Heston SDEs

We present a detailed analysis of observable moment-based parameter estimators for the Heston SDEs jointly driving the rate of returns $(R_{t})$ and the squared volatilities $(V_{t})$ . Since volatilities are not directly observable, our parameter estimators are constructed from empirical moments of realised volatilities $(Y_{t})$ , which are of course observable. Realised volatilities are computed over sliding windows of size $\varepsilon $ , partitioned into $J(\varepsilon )$ intervals. We establish criteria for the joint selection of $J(\varepsilon )$ and of the subsampling frequency of return rates data. We obtain explicit bounds for the $L^{q}$ speed of convergence of realised volatilities to true volatilities as $\varepsilon \to 0$ . In turn, these bounds provide also $L^{q}$ speeds of convergence of our observable estimators for the parameters of the Heston volatility SDE. Our theoretical analysis is supplemented by extensive numerical simulations of joint Heston SDEs to investigate the actual performances of our moment-based parameter estimators. Our results provide practical guidelines for adequately fitting Heston SDE parameters to observed stock price series.
Regulators of G protein Signaling (RGS) proteins (version 2020.5) in the IUPHAR/BPS Guide to Pharmacology Database

Regulator of G protein Signaling, or RGS, proteins serve an important regulatory role in signaling mediated by G protein-coupled receptors (GPCRs). They all share a common RGS domain that directly interacts with active, GTP-bound Gα subunits of heterotrimeric G proteins. RGS proteins stabilize the transition state for GTP hydrolysis on Gα and thus induce a conformational change in the Gα subunit that accelerates GTP hydrolysis, thereby effectively turning off signaling cascades mediated by GPCRs. This GTPase accelerating protein (GAP) activity is the canonical mechanism of action for RGS proteins, although many also possess additional functions and domains. RGS proteins are divided into four families, R4, R7, R12 and RZ based on sequence homology, domain structure as well as specificity towards Gα subunits. For reviews on RGS proteins and their potential as therapeutic targets, see e.g. [183, 411, 446, 450, 451, 558, 566, 345, 9].
Early development in Kelletia kelletii (Forbes, 1850) (Gastropoda: Buccinidae), an Eastern Pacific gastropod with planktonic larvae

Kelletia kelletii (Forbes, 1850) is an intertidal to subtidal marine buccinid gastropod with a range from California, USA, to Baja California, Mexico. Many characteristics of its mating behavior, general life history, and larval biology are known, but details about its larval morphology and behavior are lacking. Here, aspects of its larval development and morphology during early ontogeny are chronicled, including larval velar form and function, asymmetrical development, particle ingestion, larval yolk reserves, and larval shell morphology. Snail oviposition behavior was observed in aquaria and egg capsules were dissected at different stages of development and examined under optical and scanning electron microscopy. Egg capsules had undeveloped eggs and/or embryos that were not ingested by K. kelletii larvae. Hatching time (natural excapsulation) varied between 37 to 55 d depending on water conditions, and endogenous yolk reserves were present in most veligers at capsule emergence. Pre-hatching veligers could swim in the plankton if excapsulated at 27 d and had symmetrical velar lobes but different sized cephalic tentacles. At 2.5 weeks in the plankton, both cephalic tentacles and velar lobes were asymmetrical, with those on the larvae’s right larger than those on their left. Larval shells were brittle and poorly mineralized at excapsulation but fully mineralized with an apertural beak and proto-siphonal canal by 2.5 weeks in the plankton. Particle capture and transport through the velar lobes to the mouth was possible in pre-hatching veligers, but ingestion only occurred in emerged veligers when yolk stores were depleted. Chronicling early ontogeny and its sequence, as in this study, is essential to the understanding of larval development and its evolution in gastropods, and to comparative studies of larval biology in the Buccinidae.
Drug Policy: Insights from Mathematical Analysis

Illicit drugs create serious health problems whose management is complicated by illegality, poor data, and market dynamics. Quantitative analysis can and does play a key role in clarifying implications of strategic choices concerning collective response to these problems. This chapter summarizes key arguments and findings concerning the effectiveness of various prevention and treatment strategies, including supply control measures. Among them are that conventional prevention programs are not very effective in an absolute sense, but they are so cheap that they are cost-effective. Likewise, treatment programs can be cost-effective despite very high relapse rates, in part because periods of heavy use impose such enormous costs on society. Enforcement can play a key role in diffusing the positive feedback loop created by contagious spread of initiation during the early phase of new drug epidemics because of its unique ability among diverse drug control interventions to focus its impact on the present.
Software Product Certification

Here, we examine the process and challenges of certifying software-intensive systems. We will first review the interpretation of the term, certification. We then review different types of certification processes, and discuss challenges to forming software certification procedures. And finally, we discuss a strategy for gaining the maximum benefit from performing certification by formulating the correct procedures that are needed to roll out a certification plan by recommending appropriate guidelines to those developers whose products will be judged. Keywords: quality of service; decertification; miscertification; recertification; verification and validation; systems of systems
Towards the design and development of an active needle for therapeutic procedures

The accuracy of many needle-based therapeutic procedures depends on the placement of the needle tip to desired locations. In many of these procedures, lack of actuation and dexterity of the device limits the surgeon's capability to compensate for the probable errors. To overcome these limitations shape memory alloy (SMA) wire actuators were attached to the needle body to provide contraction forces to bend the needle tip. In this paper a miniature prototype of a SMA activated needle was designed and developed. To obtain an enhanced deflection a flexure element was included in the design. A shape memory polymer (SMP) was used as the flexure component to provide dexterity and to electrically insulate the two segments of our needle. The SMP's properties to recover its initial shape, upon applying heat above its glass transition temperature, was utilized to bring the device back to its original configuration after each time of activation.
Fabrication and operating characteristics of carbon nanotube diode

Carbon nanotubes (CNTs) are one of the most diverse nano-scale materials that have been investigated for many practical and commercial applications. In this work we have fabricated a diode using CNTs and the operating characteristics of a CNT diode are presented.
Abstract 353: Characterization Of Human Plasma Proteome Dynamics Using Deuterium Oxide

Protein turnover half-life is a critical determinant of cardiac homeostasis and can reveal previously unknown disease mechanisms. We recently developed a theoretical method to quantify protein half-life in human using stable isotopes in deuterium oxide (D2O). Our goal in the present study is to demonstrate the immediate clinical translation potential of the method by evaluating its safety, feasibility, efficacy, and reproducibility in 10 healthy human subjects. The enrolled human subjects (4 females/6 males; age 22 - 51 y/o; body weight 51 - 108 kg) were labeled with a tailored protocol (UCLA IRB#12-000899), wherein each subject orally consumed weight-adjusted doses of (~45 mL each) 70% D2O daily for 14 days to enrich body water and proteins with deuterium. Throughout labeling, the subjects maintained regular food and fluid intake, and normal daily activities. Vital signs and medical health questionnaires were taken daily till 14 days post-labeling. We followed long-term physical conditions and the physiological clearance of D2O from body water for up to 240 days post-labeling, finding no physiological effects or signs of discomfort. To monitor label enrichment and post-labeling clearance in the subjects, we measured the D2O level of plasma and saliva samples with GC-MS. Both body fluids were reliable sources for monitoring label enrichment kinetics, giving consistent values of individual enrichment levels (0.9-2.2%) and rates (0.15-0.40 d−1) in all subjects. Post-labeling D2O level naturally subsided with a characteristic half-life of ~7 days (0.1 d−1). With LC-MS and the in-house informatics platform Proturn, we successfully characterized the turnover dynamics of >600 human plasma proteins, the largest such human dataset to-date. We detected diverse protein half-life in plasma, e.g., from albumin (18.3 d) to IGF2 (8 h). Importantly, the method can quantify protein half-life with only a single time point, suggesting it can be used to study the dynamics of one single cardiac biopsy (e.g., during heart transplant). In summary, D2O labeling is a safe, accessible, and effective technique for widespread clinical investigations of protein turnover dynamics. We further discuss its implications in understanding cardiac disease mechanisms.
Paracrine Regulation of Epithelial Progesterone Receptor by Estradiol in the Mouse Female Reproductive Tract

Regulation of progesterone receptor (PR) by estradiol-17beta (E(2)) in mouse uterine and vaginal epithelia was studied. In ovariectomized mice, PR expression was low in both vaginal stroma and epithelium, but high in uterine epithelium. E(2) induced PR in vaginal epithelium and stroma, but down-regulated PR in uterine epithelium. Analysis of estrogen receptor alpha (ERalpha) knockout (ERKO) mice showed that ERalpha is essential for E(2)-induced PR expression in both vaginal epithelium and stroma, and for E(2)-induced down-regulation, but not constitutive expression of PR in uterine epithelium. Regulation of PR by E(2) was studied in vaginal and uterine tissue recombinants made with epithelium and stroma from wild-type and ERKO mice. In the vaginal tissue recombinants, PR was induced by E(2) only in wild-type epithelium and/or stroma. Hence, in vagina, E(2) induces PR directly via ERalpha within the tissue. Conversely, E(2) down-regulated epithelial PR only in uterine tissue recombinants constructed with wild-type stroma. Therefore, down-regulation of uterine epithelial PR by E(2) requires stromal, but not epithelial, ERalpha. In vitro, isolated uterine epithelial cells retained a high PR level with or without E(2), which is consistent with an indirect regulation of uterine epithelial PR in vivo. Thus, E(2) down-regulates PR in uterine epithelium through paracrine mechanisms mediated by stromal ERalpha.
The Relationship of the Prepartum Diet to the Carotene and Vitamin A Content of Bovine Colostrum

Summary A study has been made of the relationship of the prepartum diet to the vitamin A and carotene content of bovine colostrum. Four different rations were fed to 29 Holstein and 4 Guernsey heifers during the last 60 days of their gestation periods. The rations were a low-carotene ration of wheat straw and a concentrate mixture; a standard dry-cow ration of concentrate, mixed hay and corn silage; the standard ration supplemented with one million I.U. of carotene daily; and the standard ration supplemented with one million I.U. of vitamin A daily. Colostrum from cows receiving the low-carotene ration contained significantly less vitamin A per gram of butterfat than did colostrum from cows receiving the standard dry-cow ration. The carotene content per gram of butterfat in the colostrum from the carotene-supplemented cows was significantly higher than that from the other groups, although the vitamin A content was not increased. Colostrum from cows receiving the vitamin A supplement contained an average of 687 μ g. per 100ml. or 164.5 μ g. per gram of butterfat, while the colostrum from the standard dry-cow ration group contained only 374 μ g. per 100ml. or 91 μ g. per gram of butterfat, showing that the vitamin A content of colostrum may be influenced by the prepartum diet. Regardless of the form of vitamin A in the ration, the ester form of vitamin A predominated in the colostrum. Highly significant positive correlations were found between the plasma carotene and vitamin A of the cows 18 days before calving and the carotene and vitamin A content of the colostrum.
The antagonism of nicotine-induced cardiovascular responses by DMAE and DEO analogs.

A series of quaternary ammonium compounds consisting of 4,4′-bis-[N-(2′,2-diethoxyethyl)-N,N-dimethylammonioacetyl]-biphenyl dibromide (DMAE) and 4,4′-bis-[N,N-di(2-ethoxyethyl)-N-methylammonioacetyl]-biphenyl dibromide (DEO) analogs was investigated for selective nicotine antagonism. Each series of compounds contained the monophenyl (MPh.DMAE, MPh.DEO); biphenyl (DMAE, DEO); terphenyl (TPh.DMAE, TPh.DEO); half-molecule (12DMAE, 12DEO); p-phenyl half-molecule (p-PH.−12DMAE, p-Ph.−12DEO) and biphenyl half-molecule p-BPh.−12DMAE, p-BPh.−12DEO) analogs. Studies were conducted on isolated spontaneously beating guinea pig atria and anesthetized dogs. Relative potencies of the DMAE and DEO series to antagonize the nicotine (20 μg/ml) induced positive chronotropic effect of the guinea pig atria were determined as follows: DMAE (1.0); TPh.DMAE (0.82); p-Ph.−12DMAE (0.59); DEO (0.54); MPh.DMAE (0.27); TPh.DEO (0.26); MPh.DEO (0.18); p-Ph.−12DEO (0.16); 12DMAE (0.03); 12DEO (0.02); p-BPh.−12DMAE (<0.01); p-BPh.−12DEO (<0.01) and C-6 (0.85). The I50 to antagonize nicotine induced responses by DMAE was 0.13 μM (0.10 μg/ml). Several of the above analogs were studied in the dog and their ability to antagonize nicotine (100 μg/kg) induced positive chronotropic effects were compared with their ability to inhibit transmission through the stellate or the superior cervical ganglia. The I50 doses of the drugs antagonizing nicotine, impairing superior cervical ganglionic transmission' and the corresponding fold shifts in the dose—response curves follow: DMAE (120 μg/kg, 3.0 mg/kg, 25); TPh.DMAE (40 μg/kg, 1.10 mg/kg, 30), DEO (45 μg/kg, 1.30 mg/kg, 25) and C-6 (140 μg/kg, 0.42 mg/kg, 3.0). These findings are suggestive of the hypothesis that receptors normally activated by endogenously ACh in the stellate or superior cervical ganglia of the dog may be dissociated from those receptors activated by nicotine which results in an increase in blood pressure or heart rate. Clinical implications are that TPh.DMAE as well as other DMAE analogs may pose less of a problem with hypotension than hexamethonium as a nicotine antagonist.
The electrical resistivity and thermoelectric power of Ca and Sr above 300 K

Abstract The electrical resistivity and thermoelectric power of pure Ca and Sr and of intentionally hydrogenated Sr have been determined from 300 K to 850 K. The f.c.c.-b.c.c. transition in Ca was found to occur near 718 K and to have a large effect on the thermopower, while apparently not affecting the resistivity. By comparison, the literature values are of a complex nature, probably owing to a variety of undefined impurities and phases. Pure Sr also undergoes a high temperature f.c.c.-b.c.c. transition, which has a large effect on both resistivity and thermopower. Hydrogenation of Sr causes an additional, h.c.p., phase to appear, which has a very large effect on the resistivity.
Interfacial properties of amphipathic β strand consensus peptides of apolipoprotein B at oil/water interfaces

The region between residues 968 and 1882 of apolipoprotein B (apoB-21 to apoB-41) is rich in amphipathic β strands (AβSs) and promotes the assembly of primordial triacylglyceride (TAG)-rich lipoproteins. To understand the importance of AβS in recruiting TAG, the interfacial properties of two AβS consensus peptides, P12 and P27, were studied at dodecane/water (DD/W) and triolein/water (TO/W) interfaces. P12 (acetyl-LSLSLNADLRLK-amide) and P27 (acetyl-LSLSLNADLRLKNGNLSLSLNADLRLK-amide), when added into the aqueous phase surrounding a suspended oil drop (dodecane or triolein), decreased the interfacial tension (γ) in a concentration-dependent manner. At the DD/W interface, 1 × 10−5 M P12 decreased γ to ∼20 mN/m and 6.6 × 10−6 M P27 decreased γ to ∼13 mN/m. At the TO/W interface, 1.5 × 10−5 M P12 decreased γ to ∼14 mN/m and 9.0 × 10−6 M P27 decreased γ to ∼12 mN/m. The surface area of both peptides was between 11.2 and 15.1 A2 per residue, consistent with β sheets lying flat on DD/W and TO/W interfaces. P12 and P27 are almost purely elastic on DD/W, TO/W, and air/water interfaces. When P12 and P27 were compressed beyond the equilibrium γ to as low as 4 mN/m, they could not be readily desorbed from either interface. These properties probably help in assembling nascent TAG-rich lipoproteins, and AβS may anchor apoB to β lipoproteins.
Expression of c-fos protein in lumbosacral spinal cord in response to vaginocervical stimulation in rats.

Abstract The pattern of vaginocervical stimulation-evoked expression of the proto-oncogene c- fos in lumbar 5-sacral 1 segments of the spinal cord of ovariectomized adult rats was mapped using immunocytochemistry. A calibrated force of mechanostimulation was applied to the vaginal cervix of experimental animals and to the perineum of control animals while they were gently restrained. The number of cells expressing c- fos was significant greater in the experimental than the control animals in laminae I, IV, V-VI and X. The implications of the present findings for elucidating the spinal pathways mediating the various behavioral, neuroendocrine and autonomic effects of vaginocervical stimulation (VS) are discussed.
Popliteal sciatic nerve block: posterior approach

The sciatic nerve may be one solid nerve, or the tibial and common peroneal nerves may be visualized within the sciatic nerve, the tibial nerve located medially and the common peroneal nerve laterally. Occasionally, the tibial and peroneal nerves are two separate nerves as soon as they descend from the sacrosciatic foramen. If the sciatic nerve is one nerve, it may divide into the tibial and common peroneal branches between 4 and 13 cm above the popliteal crease. The posterior approach to sciatic nerve block in the popliteals fossa can be performed with the patient in the prone, lateral, or supine postitions. The supine and lateral positions are ideal in the postoperative period, when the patient has difficulty assuming the prone position. The site of needle insertion is at a point 7 cm superior to a crease behind the knee and 1 cm lateral to a line that bissects the superior part of the popliteal fossa. The needle is inserted at a 45° angle and advanced to a depth of 2.5 to 5 cm until a motor response of the foot is elicited with 0.3 to 0.8 mA stimulating current. Elicited inversion or combined inversion/plantar flexion is the preferred motor response. If either one of these motor responses is not elicited easily, then the double injection technique is used. In this technique, two 15-mL injections are performed after identification of the tibial (elicited plantar flexion) and peroneal components (elicited dorsiflexion or eversion) of the sciatic nerve. If the tibial response is elicited first, the needles is moved laterally until the peroneal response is elicited. If the peroneal response is elicited first, the needle is moved medially to elicit the tibial response. A total of 35 to 40 mL mepivacaine, bupivacaine, or ropivacaine, with epinephrine, is used. Although the block is used for intraoperative anesthesia, it is increasingly being performed for postoperative analgesia.
A System for Measurement of Oxygen Consumption and Control of Inspired Carbon Dioxide

A system that monitors oxygen consumptions and replaces oxygen as needed to a spirometer under automatic control is presented. The system permits the regulation of the inspired carbon dioxide concentration at a specified level and monitoring of the expired carbon dioxide concentration.
Residents and residencies.

Abstract Residency training programs in thoracic surgery are expensive apprenticeships based in a hospital. Our present thoracic surgery residency programs evolved from nineteenth century German models, which were transferred to this country with the founding of The Johns Hopkins Hospital. Dr. William S. Halsted of that institution determined the pattern, still in use, for thoracic surgery residency programs. At present, residencies in thoracic surgery are governed by regulations dictated by the specialty board. The quality of diplomates is controlled at the distal end of the system by a harassing, expensive, and complicated system of examinations. A change in the status of board certification from that of the mark of an elite surgeon to that of a license to practice surgery is now becoming evident. To reorient residency programs to fit the times, it is suggested that the American College of Surgeons be made responsible for all surgical residency programs and that supervision of clinical residencies in general, including surgery, be through the American Medical Association. If a more widely based source of authority could be secured for the boards, their time and effort could be directed toward careful appraisal of programs and evaluation of candidates entering the programs. It is important to remember that one characteristic of a profession that separates it from a vocation is the ability of the profession to ensure its own high standards of excellence.
Ability of MEQ-Deleted MDV Vaccine Candidates to Adversely Affect Lymphoid Organs and Chicken Weight Gain

SUMMARY. CVI988 (Rispens) is currently the most effective vaccine used to protect against Marek's disease, a lymphoproliferative disease of chickens. A MEQ-deleted Marek's disease virus strain has shown promise as a vaccine candidate; however, unpublished results from vaccine safety trials suggest that this candidate vaccine induces unwanted lymphoid atrophy. The current study evaluated lymphoid atrophy at multiple time points between 2- and 8-wk postinoculation and attempted to correlate results with virus replication in the thymus. Results confirm reports that MEQ-deleted virus strains are able to cause thymus and bursa atrophy, which is most severe at 2-wk postinoculation. The MEQ-deleted virus strains induced lower body weights and relative thymus and bursa weights compared to uninoculated and Rispens-vaccinated chickens at multiple time points between 2- and 8-wk postinoculation. Both MEQ-deleted virus strains produced high levels of in vivo virus replication in the thymus at rates significantly grea...
DOUBLE-BLIND ASSESSMENT OF STIMULANT MEDICATION FOR ATTENTION DEFICIT DISORDER: A Model for Clinical Application

A double-blind procedure is presented for assessing the response to stimulant medication among children with attention deficit disorder. Of 94 children treated with methylphenidate and placebo, 70 demonstrated a positive response to active medication. It is suggested that a double-blind investigation is an efficient means of securing meaningful treatment information, particularly in difficult family or clinical situations.
Bleeding following endoscopic sphincterotomy: angiographic management by transcatheter embolization

Transcatheter embolization is a well-established and effective method for the control of bleeding from the upper gastrointestinal tract and often represents the preferred alternative to more invasive surgical management. The applications of this technique for the management of bleeding following endoscopic sphincterotomy have not been reported previously. Of five patients referred for arteriography with life-threatening postsphincterotomy bleeding, active bleeding from branches of the gastroduodenal artery was demonstrated in four. Embolization of this vessel with Gelfoam controlled the bleeding in all three patients in whom it was attempted. Arterial stenosis and spasm precluded such treatment in one patient. The fifth patient was not bleeding at the time of arteriography. There were no complications from these procedures. Our experience shows that postsphincterotomy bleeding can be safely and effectively controlled by transcatheter embolization, thereby avoiding surgery which is associated with significant morbidity and mortality in this setting.