cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal performance of helical coils with reversed loops and wire coil inserts

Abstract Flow and heat transfer characteristics of water in a newly designed helical coil heat transfer device were investigated in this experimental study. The conventional helical coil configuration was structurally modified aiming to improve its heat transfer performance. Specifically, 360° plastic tubing with or without wire coil inserts was added after each 180° of the main helical coil loop to enhance fluid mixing and redistribute the flow, which should have a direct effect on the thermal performance of the helical coil heat transfer device. Experimental results show that the structural modifications of the conventional helical coil configuration led to enhanced heat transfer in the test section while the pressure drop penalty increased slightly. Furthermore, the heat transfer performance of the overall test section improved by using wire coil inserts in the plastic tubing after every 180° of the main helical coil loop. The results reveal that the modified helical coil section offers a good trade-off between heat transfer enhancement and pressure drop penalty.
It Takes a Village: Utilizing a Community‐based Longitudinal Integrated Clerkship Model at a Regional Medical Campus to Provide the Core Emergency Medicine Clerkship Experience

Objectives The objective was to evaluate the efficacy of a required emergency medicine (EM) experience embedded in a new community-based longitudinal integrated clerkship (LIC) for participating students and faculty. Methods We developed and implemented a community-based LIC EM experience. The experience included 10 clinical shifts, one emergency medical services prehospital care shift, four didactic sessions, one reflection, and an emergency medicine simulation session. Students' outcomes were assessed using end-of-year surveys, focus groups, an emergency medicine subject examination, simulation performance, and clinical evaluations of the students by faculty. Faculty were recruited, underwent faculty development, and were evaluated by students. Faculty perceptions were gathered from a focus group and faculty retention rates were collected. Results Three cohorts of LIC students (total N = 61) have completed their core emergency medicine experience in our community-based LIC. Among students, 76% to 95% rated the overall quality of teaching as very good or excellent and 66% to 100% rated the quality of learning in their community-based setting as very good or excellent. All students who passed the EM subject examination achieved the clinical competencies of the experience based on clinical evaluations. Among faculty, we have retained greater than 95% each year and they have reflected positively on their precepting experience. Conclusions Implementing a required EM experience within a community-based LIC model can be an effective learning experience for students and perceived positively by community-based faculty. This model may offer an opportunity to expand clinical learning experiences in EM.
Acute vasodilator testing following Fontan palliation: an opportunity to guide precision care?

Background Pulmonary vasodilators improve the functional capacity of some patients with pulmonary arterial hypertension. However, pulmonary vasodilators frequently fail to improve unequivocal endpoints of efficacy in patients with lower pulmonary arterial pressures who have been palliated with a Fontan procedure. Objective Haemodynamic measurements and the results of acute vasodilator testing in a subset of patients were reviewed to determine whether some patients acutely respond more favourably to sildenafil and might be candidates for precision care with a phosphodiesterase V inhibitor long term. Materials and methods Heart catheterisation was performed in 11 patients with a Fontan procedure. Haemodynamic measurements were performed before and after treatment with intravenous sildenafil (mean 0.14, range 0.05-0.20 mg/kg). Results (mean ± standard deviation) were compared by paired and unpaired t-tests to identify statistically significant changes. Results Sildenafil was acutely associated with changes in mean pulmonary arterial pressure, transpulmonary gradient, indexed blood flow, and indexed vascular resistance. Changes in mean pulmonary arterial pressure were greater for patients with a mean pulmonary arterial pressure greater than 14 mmHg compared to patients with a lower mean pulmonary arterial pressure. Changes in transpulmonary gradient were greater for patients with a transpulmonary gradient greater than 5 mmHg compared to patients with a lower transpulmonary gradient. Conclusion Sildenafil acutely decreases mean pulmonary arterial pressure and transpulmonary gradient and causes greater acute changes in patients with higher mean pulmonary arterial pressures and transpulmonary gradients. Haemodynamic measurements and vasodilator testing might help to guide precision care following Fontan palliation.
Analysis of 206 critical hand-foot-mouth disease cases with hypertension

手足口病(HFMD)是由肠道病毒引起的儿童肠道急性传染病,近年来该病的发病率及危重病例报告数呈上升趋势,严重威胁儿童的健康.我院为云南省、昆明市重症HFMD定点收治医院.现将我院2012年1-6月收治的206例具有高血压表现的危重型HFMD病例分析如下. 关键词：手足口病;高血压;病原学;治疗
Axial and pseudoscalar form factors from charged current quasielastic neutrino-nucleon scattering

We study the scattering of neutrinos on polarized and unpolarized free nucleons, and also the polarization of recoil particles in these scatters. In contrast to electromagnetic processes, the parity-violating weak interaction gives rise to large spin asymmetries at leading order. Future polarization measurements could provide independent access to the proton axial structure and allow the first extraction of the pseudoscalar form factor from neutrino data without the conventional partially conserved axial current (PCAC) ansatz and assumptions about the pion-pole dominance. The pseudoscalar form factor can be accessed with precise measurements with muon (anti)neutrinos of a few hundreds MeV of energy or with tau (anti)neutrinos. The axial form factor can be extracted from scattering measurements using accelerator neutrinos of all energies.
E-233 Ruptured intracranial aneurysms treated with the pipeline embolization device: a systematic review and pooled analysis of individual patient data

Objectives The pipeline embolization device (PED) is a flow diverting stent used for the treatment of intracranial aneurysms. This technique necessitates dual antiplatelet therapy (DAPT) and aneurysm occlusion is delayed. Despite these limitations, the PED is used for a subset of ruptured aneurysms not amendable to traditional treatment techniques. We seek to evaluate the safety and efficacy of this practice. Methods A systematic review of the PubMed and MEDLINE databases from January of 2011 to October of 2019 was performed to identify studies of ruptured intracranial aneurysms treated with the PED. Inclusion required publication in English, a minimum of 5 cases and reporting of clinical outcome and complications. Duplicate patient reports from the same author(s) were excluded. Individual patient data was collected for pooled analysis. Results Individual patient data was collected for 140 patients with 140 ruptured aneurysms treated with the PED from 11 studies. Seventy-four (73.3%) out of 101 patients were female and the mean age 50.9 years. Hunt and Hess score was 1–3 for 84.2% of patients. Mean aneurysm size was 6.0 mm and the majority were blister (51.0%) or dissecting (26.9%) in morphology. Aneurysms re-hemorrhaged following PED placement in 3 (2.1%) cases: 3 mm saccular ICA aneurysm, 21 mm saccular ICA aneurysm, and 34 mm fusiform ICA aneurysm. Larger aneurysm size (p=0.05) and saccular morphology (p=0.01) were associated with aneurysm re-hemorrhage. Of the 125 patients with radiographic follow up, 104 (83.2%) had complete aneurysm occlusion. Smaller aneurysm size was associated with complete aneurysm occlusion (p=0.03). Symptomatic neurologic complications occurred in 18 (12.4%) and symptomatic neurologic complications were associated with increasing Hunt and Hess score and Fisher grade. Conclusion The majority of ruptured aneurysms treated with the PED and reported in the literature were blister or dissecting in morphology. Treatment of ruptured aneurysms was associated with a re-hemorrhage rate of 2.1% and complete occlusion rate of 83.2%. Flow diversion with the PED is a viable option for ruptured aneurysms not amendable to traditional surgical and endovascular treatment options. Disclosures P. Foreman: None. A. Ilyas: None. M. Cress: None. J. Vachhani: None. R. Hirschl: None. C. Griessenauer: None.
Conducting Epidemiological Research and Clinical Trials in a Lifestyle Medicine Program

Cardiometabolic diseases, including obesity, type 2 diabetes, and a variety of cardiovascular diseases constitute a global pandemic. The prevalence of cardiometabolic diseases and associated medical costs have increased dramatically in recent years, bringing greater health care burden to communities, families, and individuals. Therefore, identifying the strategies for disease prevention, particularly those that are safe, cost-effective, and readily accessible, is of both public health and clinical significance. This chapter provides the detailed logistics, principles, and methods of building academic resources, including infrastructure, that are essential for conducting epidemiological research and clinical trials in an academic health science center, with a special focus on lifestyle medicine. For illustration, substantive work studying the roles of dietary factors in relation to cardiometabolic health outcomes and comprehensive lifestyle medicine are presented in the context of projects conducted at two academic research institutions: University of California, Los Angeles (UCLA) and Brown University.
Conference Report From The 57th Design Automation Conference

The 57th Design Automation Conference (DAC) was the first virtual DAC in its 57th year history. It was originally planned to be held at the Moscone West Conference Center from July 19 to July 23, 2020, but due to COVID-19, the DAC executive committee and sponsors, ACM/IEEE, jointly decided to go for a virtual event. DAC 2020 was held virtually from July 21 to July 24, and the virtual content was extended for one additional week for the registered participants. It is a great honor to serve as the Chair of the first virtual DAC.
Quantitative Prediction of Perovskite Stability Using Accelerated Testing and Machine Learning

PV technologies based on hybrid perovskites offer the potential for reducing solar cell costs, but they are particularly vulnerable to degradation by environmental factors such as moisture, oxygen, and illumination. Commercialization will require not only stable materials and device architectures but also accelerated testing protocols and models that can predict degradation from the accelerated testing data. Here, we report results from in situ photoluminescence (PL) and photoconductivity (PC) measurements during perovskite degradation with simultaneous optical transmittance (Tr) measurements or reflected dark field (DF) imaging. From PL, PC, Tr, and DF, we determine (respectively) the steady-state quasi-Fermi level splitting, the mean effective carrier diffusion length, the extent of conversion of perovskite to higher bandgap degradation products, and the extent of scattering from domains with different orientation or composition, all as a function of time during degradation. Simultaneous measurement of PL-PC-Tr or PL-PC-DF on perovskite absorbers in an environmental chamber over a wide range of humidity, oxygen, temperature, and illumination levels yields a rich data set. We use machine learning to develop a model that accurately predicts (within 10%) the time for the diffusion length to decrease to 85% of its initial value. The model takes the environmental conditions and the first few measurements from the PL-PC-Tr or PL-PC-DF experiment as input. Thus, the model provides a framework to interpret the results of accelerated testing of absorber materials. One of the dominant features in the model of degradation for CH3NH3PbI3 is the initial rate at which transmittance increase. For devices with opaque contacts, the pixel-averaged rate of change of the intensity in dark-field images can be used in place of transmittance. Results are also presented on full PV devices with in-situ current-voltage (JV) measurements. The data from simultaneous PL-DF-JV under environmental stresses reveal intimate connection between degradation and shunts and provide a framework to extend accelerated testing to devices. Further, the presentation reveals underlying universal behavior in degradation pathways over a broad range of environmental stresses and perovskite compositions.
What improves the likelihood of people receiving genetic test results communicating to their families about genetic risk

Abstract Objective We currently rely on probands to communicate genetic testing results and health risks within a family to stimulate preventive behaviors, such as cascade testing. Rates of guidelines-based cascade testing are low, possibly due to low frequency or non-urgent communication of risk among family members. Understanding what is being communicated and why may help improve interventions that increase communication and rates of cascade testing. Methods Participants (n = 189) who were to receive both positive and negative colorectal cancer (CRC) sequencing results completed surveys on family communication, family functioning, impact of cancer in the family, and future communication of risk and were participants in eMERGE3. Questions were taken from existing surveys and administered electronically using email and a web driven tool. Results Common family member targets of CRC risk communication, before results were received, were mothers and fathers, then sisters and grandchildren and finally, children and brothers. A communication impact score of 0.66 (sd = 0.83) indicated low-to-moderate communication impact. Age and education were significantly associated with frequency of familial communication, but not on the cancer-related impact of familial communication. Conclusions There is infrequent communication about cancer risk from probands to family members. Practice Implications These results demonstrate an opportunity to help families improve communication.
Computer/experiment integration for unsteady aerodynamic research

The use of a minicomputer for the acquisition and analysis of unsteady aerodynamic data is described. Some of the novel features of the system include: on-line digitization, a signal-averaging algorithm, Fourier decomposition, graphical display, and on-line theoretical computations to compare with the ongoing experiment. The system's capabilities are described using some data from a recently completed oscillating airfoil experiment.
Implementing specification freedoms

Abstract The process of converting formal specifications into valid implementations is central in the development of reliable software. As formal specification languages are enriched with constructs to enhance their expressive capabilities and as they increasingly afford specificational freedoms by requiring only a description of intended behavior rather than a prescription of particular algorithms, the gap between specification and implementation widens so that converting specifications into implementations becomes even more difficult. A major problem lies in the mapping of high-level specification constructs into an implementation that effects the desired behavior. In this paper, we consider the issues involved in eliminating occurrences of high-level specification-oriented constructs during this process. Mapping issues are discussed in the context of our development methodology, in which implementations are derived via the application of correctness-preserving transformations applied to a specification language whose high-level expressive capabilities are modeled after natural language. After the general discussion, we demonstrate the techniques on a real system whose specification is written in this language.
A new soft-switching pulse-width-modulated boost converter

In this paper, we propose a zero-current/voltage-switching (ZCVS) pulse-width-modulated (PWM) boost converter which is accomplished by adding a second switch in parallel with the resonant capacitor of the zero-current-switching (ZCS) quasi-resonant boost converter. It is shown that the primary switch of the new converter possesses zero-current-switching while the other one possesses zero-voltage-switching. Since the new converter contains two switches, by properly controlling both switches, the pulse-width-modulation can be achieved. By using the state plane diagram, the steady state analysis is conducted and a complete set of the characteristic curves are generated. To verify the theoretical work, computer simulations are also provided. >
Medical Paternity and 'wrongful life'.

hen medical innovations make it possible to prevent the births of children with significant physical or mental handicaps, children who will require very expensive care during their lifetimes, litigation is a predictable aftermath. Thus, both genetic counseling and amniocentesis are the subject of an increasing number of courtroom confrontations between parents and physicians. While making physicians pay for the defects of the children of their pregnant patients seems to some to smack of "medical paternity," it is the measure of damages, not the application of traditional medical malpractice principles, that makes these cases appear novel.
Directional coupling with optical vortex soliton pair

We have demonstrated the propagation of an optical vortex soliton (OVS) in the center of a green Ar ion laser beam in a self-defocusing nonlinear medium. The dark core of an OVS has actually a graded refractive-index profile, which is the imprint of the OVS in the nonlinear medium.
Functional variation among polysaccharide-hydrolyzing microbial communities in the Gulf of Mexico

Abstract Marine polysaccharides are structurally diverse, as are the microbial communities capable of remineralizing them. Variations in the diversity, richness, and metagenome content of pelagic microbial communities are well documented, but variation in the spectrum of substrates accessible to those communities is less well understood. Here we investigate variability in the abilities of microbial communities to access specific polysaccharides along lateral and depth gradients in the Gulf of Mexico. Patterns of polysaccharide degradation during long-term incubations varied in ways that could not be predicted from bulk community measurements of bacterial production and glucose metabolism. There was greater diversity of function among epipelagic communities than among mesopelagic communities, and the communities in the two deepest water samples (700 m and 905 m) were more specialized in their abilities to access specific polysaccharide structures than were shallower-water communities. Timecourses of polysaccharide hydrolysis suggest that the capacity of communities to access specific polysaccharides may be influenced in part by variability in the composition or activity of the rare biosphere.
High-performance liquid chromatographic resolution and quantification of a dilactonic antibiotic mixture (antimycin A)

Abstract High-performance liquid chromatographic (HPLC) conditions are presented for the separation and quantitative determination of a homologous antibiotic complex (antimycin A). Combined HPLC and chemical ionization mass spectrometry proved to be exceptionally useful for the structural identification of chromatographic components. Using electrochemical, fluorescence, and ultraviolet detectors, the minimum detectable amounts of the antibiotics were found to be in the ranges 0.10–1.12, 0.31–1.69, and 4.10–28.2 ng, respectively. Advantages of the preparation of Dns derivatives for use in fluorescence detection are discussed. Application of the HPLC technique to the analysis of the antibiotic mixture in organic tissues is demonstrated.
Adaptive speed regulation of gearless wind energy transfer systems

The energy of wind can be transferred to the generator either by direct connection through a gearbox or by employing an intermediate medium such as hydraulic fluid. Gearless hydraulic wind power transfer systems are considered noble candidates to transfer wind energy to generators since they can collect the energy of multiple wind turbines in one generation unit. However, non-ideal dynamics of hydraulic systems imposed by pressure drops, leakage coefficient variations, and motor/generator damping coefficient, degrade the performance of power generation. This paper introduces a model reference adaptive controller (MRAC) to maintain and track a reference speed profile at the generator of a hydraulic wind power transfer. The mathematical modeling of a gearless hydraulic wind power transfer is presented and used to generate an accurate model of the plant. The control performance is verified with simulation results, which demonstrates a close tracking profile.
The impact of climatic variation on the yield of selected crops in three California counties

Abstract The effects of variations in agroclimatically significant variables on yield and agricultural income as exemplified by four crops in three counties in central California are in vestigated. The statistical relationships between agroclimatic variables and yield are obtained through stepwise multiple regression techniques, and polynomial carve fitting. Frequency distributions and recurrence interval analyses are used to ascertain the probable maximum and minimum values of the more important climatic variables to be expected in given periods. The coefficients of the multiple regression equations associating crop yield with agroclimatic variables are used to estimate the effects of variations on yield and income. Optimum values of significant agroclimatic variables for each crop and the return period of such values are given. The response of yield to values beyond these optima is demonstrated. It is shown, in addition, that “specific climatic variations” in the variables that account for the largest percentage of the total variance in yield can have a substantial effect on yield and income. It is argued that variations of that magnitude are likely to be exceeded with greater frequency if the variability of hemispheric climate increases. The yields of the crops examined are affected differently by increases or decreases in the agroclimatic variables, prompting the conclusion that with increasing climatic variability, cropping patterns will most likely be predicted on the relative economic impact of the variations.
Superconvergence of piecewise polynomial Galerkin approximations, for Fredholm integral equations of the second kind

Piecewise polynomial Galerkin approximations for Fredholm integral equations of the second kind are shown to posses superconvergence properties in some circumstances.
The conflicts between strength and toughness

The attainment of both strength and toughness is a vital requirement for most structural materials; unfortunately these properties are generally mutually exclusive. Although the quest continues for stronger and harder materials, these have little to no use as bulk structural materials without appropriate fracture resistance. It is the lower-strength, and hence higher-toughness, materials that find use for most safety-critical applications where premature or, worse still, catastrophic fracture is unacceptable. For these reasons, the development of strong and tough (damage-tolerant) materials has traditionally been an exercise in compromise between hardness versus ductility. Drawing examples from metallic glasses, natural and biological materials, and structural and biomimetic ceramics, we examine some of the newer strategies in dealing with this conflict. Specifically, we focus on the interplay between the mechanisms that individually contribute to strength and toughness, noting that these phenomena can originate from very different lengthscales in a material's structural architecture. We show how these new and natural materials can defeat the conflict of strength versus toughness and achieve unprecedented levels of damage tolerance within their respective material classes.
Current Assessment Practice, Personality Measurement, and Rorschach Usage by Psychologists

In this study, we investigated current personality assessment practice and attitudes toward Rorschach (Exner, 2003) usage by 215 psychologists. We administered an Internet survey to members of the Society for Personality Assessment (SPA) and the American Psychological Association. Results were similar to those of past surveys, but the importance of using tests with strong psychometric properties was greater in this study. The majority of respondents reported using the Rorschach and supporting efforts to standardize and psychometrically validate the test. However, SPA members agreed more strongly than non-SPA members that the Rorschach is an effective test. Implications and directions for future research are discussed.
Hamiltonian connectedness in 3-connected line graphs

We investigate graphs G such that the line graph L(G) is hamiltonian connected if and only if L(G) is 3-connected, and prove that if each 3-edge-cut contains an edge lying in a short cycle of G, then L(G) has the above mentioned property. Our result extends Kriesell's recent result in [M. Kriesell, All 4-connected line graphs of claw free graphs are hamiltonian-connected, J. Combin. Theory Ser. B 82 (2001) 306-315] that every 4-connected line graph of a claw free graph is hamiltonian connected. Another application of our main result shows that if L(G) does not have an hourglass (a graph isomorphic to K"5-E(C"4), where C"4 is an cycle of length 4 in K"5) as an induced subgraph, and if every 3-cut of L(G) is not independent, then L(G) is hamiltonian connected if and only if @k(L(G))>=3, which extends a recent result by Kriesell [M. Kriesell, All 4-connected line graphs of claw free graphs are hamiltonian-connected, J. Combin. Theory Ser. B 82 (2001) 306-315] that every 4-connected hourglass free line graph is hamiltonian connected.
GraphX: a resilient distributed graph system on Spark

From social networks to targeted advertising, big graphs capture the structure in data and are central to recent advances in machine learning and data mining. Unfortunately, directly applying existing data-parallel tools to graph computation tasks can be cumbersome and inefficient. The need for intuitive, scalable tools for graph computation has lead to the development of new graph-parallel systems (e.g., Pregel, PowerGraph) which are designed to efficiently execute graph algorithms. Unfortunately, these new graph-parallel systems do not address the challenges of graph construction and transformation which are often just as problematic as the subsequent computation. Furthermore, existing graph-parallel systems provide limited fault-tolerance and support for interactive data mining.We introduce GraphX, which combines the advantages of both data-parallel and graph-parallel systems by efficiently expressing graph computation within the Spark data-parallel framework. We leverage new ideas in distributed graph representation to efficiently distribute graphs as tabular data-structures. Similarly, we leverage advances in data-flow systems to exploit in-memory computation and fault-tolerance. We provide powerful new operations to simplify graph construction and transformation. Using these primitives we implement the PowerGraph and Pregel abstractions in less than 20 lines of code. Finally, by exploiting the Scala foundation of Spark, we enable users to interactively load, transform, and compute on massive graphs.
Mechanical purification of torpedo stage somatic embryos of Daucus carota L.

A filtering unit was designed and constructed that concentrates and purifies torpedo-stage embryos, from carrot (Daucus carota L.) embryo suspensions. The filtering unit was composed of three sections, each containing a screen disk. Purification efficiency of a series of three screen size combinations was evaluated using 10 to 15 ml of 23- to 30-day-old embryo suspensions. Under optimal conditions where the first screen was a 1000 micron in size, >84% of the total number of torpedo embryos were concentrated in the purified fraction. Purified fractions contained more than double the percentage of torpedo embryos when compared to unfiltered suspensions. This filtering unit provided a simple method for concentrating and purifying torpedo embryos from a suspension.
Purged: Undocumented Students, Financial Aid Policies, and Access to Higher Education:

This article examines how the denial of financial aid constrains undocumented students from pursuing higher education and discusses the interlocking relationship between federal immigration and higher education policies. Reporting on research data identifying that undocumented students pay for their education through work, family contributions, few scholarships, and strategies such as working more and taking fewer classes, this article also links the stress placed on undocumented students and their families to Latino retention and graduation rates.
Majority rule outcomes and the choice of germaneness rules

Much work in the field spatial models has concerned the conditions under which majority rule is stable in a multi-dimensional policy space. Some have suggested that legislative practices such as germaneness rules (Shepsle, 1979; Denzau and Mackay, 1981, 1983; Krehbiel, 1987) and different types of agendas (Shepsle and Weingast, 1984; Banks, 1985; McKelvey, 1986) either induce stability or limit the set of possible outcomes. However, they do not consider how stable the choice of these rules may be. This paper shows how the choice of germaneness rules inherits the instability of the policy space. While the use of any particular germaneness rule limits the set of possible outcomes (Feld and Grofman, 1988), it is shown that the process of choosing these rules is unstable.
Synthesis of serotonin by pineal glands of the rat in organ culture.

THE pineal gland of the rat has been shown to contain large quantities of the indole serotonin1. This organ can also metabolize serotonin by a unique pathway to form the hormone melatonin (5-methoxy N-acetyltryptamine)2. The content of serotonin1,3 and the activity of the melatonin-forming enzyme4 in the pineal have been found to vary with a 24 h cycle. These rhythms are controlled by information transmitted to the pineal through its sympathetic nerves3,5.
Surgical treatment of the painful temporomandibular joint.

If usual conservative therapy fails, high mandibular condylectomy brings relief of symptoms to selected patients with demonstrable articular pathologic conditions and pain definitely arising from the TMJ.
HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors

HAMP domains are signal relay modules in >26,000 receptors of bacteria, eukaryotes, and archaea that mediate processes involved in chemotaxis, pathogenesis, and biofilm formation. We identify two HAMP conformations distinguished by a four- to two-helix packing transition at the C-termini that send opposing signals in bacterial chemoreceptors. Crystal structures of signal-locked mutants establish the observed structure-to-function relationships. Pulsed dipolar electron spin resonance spectroscopy of spin-labeled soluble receptors active in cells verify that the crystallographically defined HAMP conformers are maintained in the receptors and influence the structure and activity of downstream domains accordingly. Mutation of HR2, a key residue for setting the HAMP conformation and generating an inhibitory signal, shifts HAMP structure and receptor output to an activating state. Another HR2 variant displays an inverted response with respect to ligand and demonstrates the fine energetic balance between “on” and “off” conformers. A DExG motif found in membrane proximal HAMP domains is shown to be critical for responses to extracellular ligand. Our findings directly correlate in vivo signaling with HAMP structure, stability, and dynamics to establish a comprehensive model for HAMP-mediated signal relay that consolidates existing views on how conformational signals propagate in receptors. Moreover, we have developed a rational means to manipulate HAMP structure and function that may prove useful in the engineering of bacterial taxis responses.
PCR-mediated gene replacement in Escherichia coli.

The hyper-recombinogenic properties of an E. coli strain in which the recBCD genes have been replaced by l red recombination functions were exploited in the development of a general PCR-mediated gene replacement scheme for Escherichia coli. Linear DNA substrates generated by recombinant PCR are introduced by electroporation into strains containing the recBCDD::red substitution. This technique allows for gene replacement in E. coli without prior cloning of the gene of interest. In addition, the counter-selectable marker sacB has been used to construct unmarked precise gene deletions without the need to form sacBcontaining plasmid integrates. In other experiments, electroporation of recBCDD::red strains with high concentrations of linear DNA fragments (derived from plasmid digests) gave linear transformation rates approaching 1% of the survivors of electroporation. The placement of l red and gam at a locus in the chromosome other than recBCD ( galK ) resulted in a strain that was as hyperrec as one containing the l red for recBCD substitution. The gene replacement technique described here has been used for the construction of deletion-substitution alleles of lacZ and sulA, as well as six genes important for general homologous recombination in E. coli. Three of these replacements were performed without prior cloning of the genes. © 2000 Elsevier Science B.V. All rights reserved.
Managing Business Crises: From Anticipation to Implementation

The article presents a review of the book “Managing Business Crises: From Anticipation to Implementation,” by John Burnett.
The glove rattling induction maneuver (GRIM): A valuable angiographic technique

A technique in which the attending radiologist can facilitate various angiographic maneuvers by the learning radiology resident is described. It is simple, quick, and inexpensive; its usefulness was demonstrated in a prospective study.
Variation in Invertebrate and Fish Communities Across Floodplain Ecotones of the Altamaha and Savannah Rivers

In floodplains of large rivers, different ecotones—zones of transition between adjacent ecological systems—develop where the river and uplands interact with the floodplain. Unique communities of invertebrates and fish may develop in each of these ecotones and in the floodplain interior. In our study, we sampled the river-floodplain ecotone, the upland-floodplain ecotone, and the interior of floodplains of the Altamaha and Savannah Rivers, Georgia, USA to assess how water quality, invertebrate community structure, total invertebrate abundance and biomass, and fish abundance and species richness varied across floodplains. In terms of water quality, electrical conductivity was greatest in the river-floodplain ecotone, while pH and temperature did not vary among sites. Nonmetric multidimensional scaling ordination indicated that overall invertebrate community composition across the floodplain was similar, and was dominated by wetland organisms that likely reside permanently on the floodplain. Total abundance and biomass of invertebrates was greater in the river-floodplain ecotone than the upland-floodplain ecotone, with levels in the floodplain interior being intermediary. Fish abundance and species richness was greater in the river-floodplain ecotone than other sites. Managers should consider lateral variation in invertebrate and fish assemblages across floodplains when planning management of river-floodplain ecosystems.
Pilot study of a survey of US residents purchasing medications in Mexico: Demographics, reasons, and types of medications purchased

Abstract Medications sold only by prescription in the United States are easily obtained in Mexican pharmacies without prescriptions. Few studies have research the impact of this phenomenon in the United States. The aim of this pilot study was to determine the demographics of Americans traveling to Mexico to purchase medications, their reasons for doing so, and which medications they purchased. US residents purchasing medications in Nuevo Progreso, Mexico, were given a voluntary, self-administered questionnaire. Some questions had more than 1 potential answer. A total of 103 pharmacy consumers were approached, of whom 100 agreed to participate; no data were gathered on the 3 pharmacy consumers who declined to participate. The survey results indicated that 60.0% of participants 60 participants) had private insurance, 18.0% (18 participants) had Medicare, 3.0% (3 participants) had some other form of insurance, and 19.0% (19 participants) had no insurance at all. The primary reason cited by participants for travelling to Mexico to purchase medications was lower prices (accounting for 66.7% of all reasons given). Infection was the primary disease treated, accounting for 28.2% of types of conditions cited ( 42 149 ), and ampicillin was the drug most frequently purchased, accounting for 16.8% ( 25 149 ) of all medication purchases. This pilot study indicates that US residents travel to Mexico to purchase medications for many reasons and for many different medical conditions, including chronic conditions. The most frequently cited reason for purchasing medications in Mexico was lower prices, even among participants with some form of health insurance. This finding suggests that until drug pricing is further addressed in the United States, residents will continue to seek lower-cost alternatives for purchasing their medications, including travel to Mexico.
Lower Bounds for Testing Properties of Functions over Hypergrid Domains

We show how the communication complexity method introduced in (Blais, Brody, Matulef 2012) can be used to prove lower bounds on the number of queries required to test properties of functions with non-hypercube domains. We use this method to prove strong, and in many cases optimal, lower bounds on the query complexity of testing fundamental properties of functions over hypergrid domains: monotonicity, the Lipschitz property, separate convexity, convexity and monotonicity of higher-order derivatives. There is a long line of work on upper bounds and lower bounds for many of these properties that uses a diverse set of combinatorial techniques. Our method provides a unified treatment of lower bounds for all these properties based on Fourier analysis. A key ingredient in our new lower bounds is a set of Walsh functions, a canonical Fourier basis for the set of functions on the line. The orthogonality of the Walsh functions lets us use a product construction to extend our method from properties of functions over the line to properties of functions over hypergrids. Our product construction applies to properties over hypergrids that can be expressed in terms of axis-parallel directional derivatives, such as monotonicity, the Lipschitz property and separate convexity. We illustrate the robustness of our method by making it work for convexity, which is the property of the Hessian matrix of second derivatives being positive semidefinite and thus cannot be described by axis-parallel directional derivatives alone. Such robustness contrasts with the state of the art in the upper bounds for testing properties over hypergrids: methods that work for other properties are not applicable for testing convexity, for which no nontrivial upper bounds are known for d ≥ 2.
Facilitation of repeated free operant discrimination reversals.

Abstract Two experiments are reported which studied the effects of several parameters on responses after discrimination reversals, “errors”, by retarded subjects. In Exp. 1 fixed-ratio and variable-ratio schedules of reinforcement and access to a switching key were investigated. In Exp. 2 the effects of a schedule change (FR 25 to FR 1) prior to reversal and a “count” of four reinforcements to reversal were studied with a design which permitted determining the effects of both variables simultaneously. Both experiments showed the diminution of errors after repeated reversals that has been reported in other studies of discrimination reversals and “learning set.” Access to a switching key resulted in reliably fewer errors in three of four subjects but many errors in excess of the ratios nevertheless were emitted. The number of responses after reversals may exceed FR schedules in direct relationship to the value of the FR—the higher the FR, the greater the number of responses in excess of the ratio. Schedule change prior to reversals and regularity in programming reversals resulted in errorless switching.
Fever and right upper quadrant pain in a pregnant woman at 30 weeks' gestation.

Background A 34-year-old gravid woman with a history of ileal Crohn's disease presented at 30 weeks' gestation with a 2-week history of fever and right upper quadrant pain. An intra-abdominal abscess was suspected. Ultrasound and MRI failed to demonstrate the suspected abscess. Owing to ongoing pain and fever, the risk to the fetus of a CT scan were discussed with the patient, obstetricians and radiologists, with considerable debate about the possibility of other explanations for her symptoms. Ultimately, a CT scan revealed marked thickening of the distal ileum and confirmed diagnosis of an abscess in continuity with the inflamed bowel. Investigations Ultrasound, MRI, CT scan, urinalysis, urine culture and liver function tests. Diagnosis Crohn's disease flare complicated by an intra-abdominal abscess. Management Antibiotics (ceftizoxime, metronidazole and amoxicillin/clavulanate potassium), parenteral nutrition and ileocecectomy.
Association between infant birth weight and maternal cardiovascular risk factors in the health, aging, and body composition study.

Purpose Mothers who deliver a low-birth-weight (LBW) infant may themselves be at excess risk for cardiovascular disease. We investigated whether older women who bore LBW infants had higher blood pressure, lipid, glucose, insulin, interleukin 6 (IL-6), and C-reactive protein concentrations, and pulse wave velocity compared to women with normal-weight births. Methods Participants were 446 women with a mean age of 80 years and 47% black. Women reported birth weight and complications for each pregnancy. Analysis was limited to first births not complicated by hypertension or preeclampsia. Results Women who had delivered a first-birth infant weighing less than 2500 g had a lower body mass index (BMI) compared with women with a normal-weight (≥2500 g) infant (26.7 versus 28.4 kg/m 2 ; p = 0.02), but they had a larger abdominal circumference for BMI (97.9 versus 95.5 cm; p = 0.05). They also were marginally more likely to be administered antihypertensive medication ( p = 0.06). After adjustment for BMI, race, and age, women with a history of a small infant had elevations in systolic blood pressure ( p = 0.05) and greater IL-6 levels ( p = 0.02) and were more insulin resistant ( p = 0.05) compared with women with a normal-weight infant. Conclusions These findings suggest that a history of LBW delivery identifies women with elevated cardiovascular risk factors.
Migration inhibition of endothelial cells by lymphokine-containing supernatants

Many of the reactions of cellular immunity are mediated by soluble lymphocyte-derived factors (lymphokines). One important category of lymphokine action involves effects on cell motility. These effects have been described mainly with respect to inflammatory cells. In this report, we describe the ability of a lymphocyte product to inhibit the migration of endothelial cells in a system in vitro. The responsible factor is distinct from a previously described mediator that inhibits the migration of tumor cells. The ability of lymphocytes to influence the migration properties of endothelial cells is consistent with data of others showing a relation between the immune system and processes involving neovascularization.
Effects of weather and tides on feeding and flock positions of wintering redheads in the Chandeleur Sound, Louisiana

We studied the effects of weather and tides on percent feeding and flock positions of wintering redheads (Aythya americana Eyton) in the Chandeleur Sound, Louisiana, USA. Flock scans (n = 750) were made on 55 flocks from November through March of 1988–1989. The percent of the flock that was feeding was negatively correlated with time of day, temperature, water level, and distance of the flock from shore, and was positively correlated with wind velocity, flock size, fetch, and wave height; birds also fed more in early winter and during northerly winds. Flocks were closer to land earlier in the winter on cloudy, rainy, and windy days when waves were high, and those flocks were smaller than flocks farther from shore. Conditions associated with reduced fetch by flocks included later time of day, smaller waves, warmer air temperatures, northerly wind shifts, stronger winds, increasing cloud cover, and rain. Redheads minimized energy expenditure by foraging during low tides and in shallow water closer to shore; they increased feeding and reduced fetch during times of high thermoregulatory demands.
Field work crisis: Dilemmas, dangers and opportunities

Abstract This paper looks at the many factors which are altering radically the world of practice and the ability of schools of social work to train social work students in our current situation. It approaches some of the changes as opportunities, but also holds the profession to its historic commitment to articulate clearly to society those changes which are inimical to effective response to human need. Using some of the experiences of the Smith College School for Social Work, the author discusses some ways to rethink the contexts of clinical services and the training of students in new contexts. The further complications presented by realities of students and their expectations and the pressures of agency life are also explored.
Role of endothelial cells in early pancreas and liver development

Liver and pancreas initially develop by budding from the embryonic endoderm. The formation of these organs coincides with the appearance of endothelial cells (ECs) adjacent to the endoderm. ECs either develop in situ in organs, or are recruited by organs and are induced to form blood vessels. Recent reports on liver and pancreas have now shown that ECs also induce essential steps in organ formation such as morphogenesis and cell differentiation. This review summarizes reports on EC signaling during organogenesis and cell differentiation.
ANTI-INFLAMMATORY EFFECT OF HUMAN MILK FEEDING ON CHEMICALLY INDUCED COLITIS IN RATS. ▴ 697

ANTI-INFLAMMATORY EFFECT OF HUMAN MILK FEEDING ON CHEMICALLY INDUCED COLITIS IN RATS. ▴ 697