cssi/SciSciGPT-SciSciNet huggingface dataset:
Physiological and Biochemical Mechanisms in Host Resistance and Susceptibility to Wilt Pathogens

The literature on plant host-pathogen interactions which contribute to symptom development in vascular wilt diseases is extensive, controversial and comprises some elegant and some notso elegant studies. Certain controversies revolve around the possible roles of wilt toxins, the importance of mechanical plugging of xylem elements, the involvement of cell wall degrading enzymes, the effects and origin of plant growth regulating substances that appear to influence the wilting of plants, and the mechanisms of susceptibility and resistance to pathogens and disease development. Another poorly understood process in wilt diseases involves recognition phenomena between host and pathogen. The more we know about the various processes that contribute to a compatible or incompatible association of a plant host-pathogen relationship, the more we can appreciate the many subtle transitions and the sequential interdependence of physiological interactions between host and parasite that lead to disease development. A reading of the many excellent monographs, reviews, and symposium articles that have been written on various topics concerning wilt diseases of plants, hardly leaves much more to be said (Beckman 1964 and 1967, Duniway 1973, Mace et al 1981); yet there are concepts and some new information to be reviewed that may contribute to a better understanding of wilt diseases. The object of this essay is to focus on certain phenomena which may involve recognition between host and pathogen and the apparent cause and effect relationships among ethylene, induction of polygalacturonase activity, vascular gelation and the resulting changes in plant-water relationships that contribute to vascular wilt symptoms.
Models of the Patient-Machine-Clinician Relationship in Closed-Loop Machine Neuromodulation

Closed-loop neuromodulation represents an emerging area in clinical medicine. Neural devices capable of measuring brain function and using measurements to iteratively guide output, such as deep brain stimulation, will be a significant advance in neuromodulatory technology. The introduction of closed-loop devices, particularly “smart” machines, will require changes in clinical ethical practice. A model of the clinical relationship could be a useful tool for addressing ethical challenges arising in this new area. Traditional models of the clinical relationship, like Emanuel and Emanuel’s “four models,” are suited to current unidirectional forms of neuromodulation. An adequate model of the patient-machine-clinician relationship may need to move beyond traditional models. Thus, I explore three new models: the design model, the customer service model, and the quality monitoring model. The exploration of these models of the patient-machine-clinician relationship will benefit from keeping an Aristotelian ideal of friendship in mind.
Phosphatidic acid inhibits SNARE priming by inducing conformational changes in Sec18 protomers

Eukaryotic homeostasis relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are re-activated by Sec18/NSF driven disassembly to enable a new round of fusion. We previously found that phosphatidic acid (PA) binds Sec18 to sequester it from SNAREs. Dephosphorylation of PA dissociates Sec18 from the membrane allowing it to engage SNARE complexes. We now report that PA induces conformational changes in Sec18 protomers, while hexameric Sec18 cannot bind PA membranes. The association of Sec18 with PA was shown to be sensitive to membrane curvature, suggesting that regulation could vary on different organelles in a curvature dependent manner. Molecular dynamics showed that PA binding sites exist on the D1 and D2 domains of Sec18 and that residues needed for binding were masked in the hexameric form of the protein. Together these data indicate that PA regulates Sec18 function through altering protein architecture and stabilizing membrane-bound protomers.
Predicting Protein Functional Sites with Phylogenetic Motifs: Past, Present and Beyond

More than sequence or structure, function imposes very tight constraints on the evolutionary variability within a protein family. As such, numerous functional site prediction methods are based on algorithms to uncover conserved regions that lead to conserved function. Nevertheless, evolution does allow for some systematic variability within functional regions. Based on this tenet, we have introduced the MINER algorithm to predict functional regions from phylogenetic motifs. Specifically, our approach identifies alignment fragments that parallel the overall phylogeny of the family, which are more likely to be functional due to increased evolutionary signature. In this chapter, we provide an overview of the method, summarize recent developments, and comment on future work.
l-Glutamine and the Dawn of Combination Therapy for Sickle Cell Disease.

In 2017, the U.S. Food and Drug Administration approved l-glutamine (USAN, glutamine) for the prevention of acute vaso-occlusive pain events in persons with sickle cell disease who are older than 5...
Opportunistic Measurement of Skeletal Muscle Size and Muscle Attenuation on Computed Tomography Predicts 1-Year Mortality in Medicare Patients.

BACKGROUND Opportunistic assessment of sarcopenia on CT examinations is becoming increasingly common. This study aimed to determine relationships between CT-measured skeletal muscle size and attenuation with 1-year risk of mortality in older adults enrolled in a Medicare Shared Savings Program (MSSP). METHODS Relationships between skeletal muscle metrics and all-cause mortality were determined in 436 participants (52% women, mean age 75 years) who had abdominopelvic CT examinations. On CT images, skeletal muscles were segmented at the level of L3 using two methods: (a) all muscles with a threshold of -29 to +150 Hounsfield units (HU), using a dedicated segmentation software, (b) left psoas muscle using a free-hand region of interest tool on a clinical workstation. Muscle cross-sectional area (CSA) and muscle attenuation were measured. Cox regression models were fit to determine the associations between muscle metrics and mortality, adjusting for age, sex, race, smoking status, cancer diagnosis, and Charlson comorbidity index. RESULTS Within 1 year of follow-up, 20.6% (90/436) participants died. In the fully-adjusted model, higher muscle index and muscle attenuation were associated with lower risk of mortality. A one-unit standard deviation (SD) increase was associated with a HR = 0.69 (95% CI = 0.49, 0.96; p = .03) for total muscle index, HR = 0.67 (95% CI = 0.49, 0.90; p < .01) for psoas muscle index, HR = 0.54 (95% CI = 0.40, 0.74; p < .01) for total muscle attenuation, and HR = 0.79 (95% CI = 0.66, 0.95; p = .01) for psoas muscle attenuation. CONCLUSION In older adults, higher skeletal muscle index and muscle attenuation on abdominopelvic CT examinations were associated with better survival, after adjusting for multiple risk factors.
Prenatal Point-of-Care Tobacco Screening and Clinical Relationships.

PURPOSE Up to one-third of female smokers with Medicaid deny tobacco use during pregnancy. Point-of-care urine tests for cotinine, a tobacco metabolite, can help to identify women who may benefit from cessation counseling. We sought to evaluate patient and clinician perspectives about using such tests during prenatal care to identify smokers, with particular focus on the impact of testing on clinical relationships and the potential for tobacco cessation. METHODS We conducted 19 individual interviews and 4 focus groups with 40 pregnant or postpartum women covered by Medicaid who smoked before or during pregnancy. Patients also took the urine cotinine test and received sample results. Interviews were conducted with 20 health care practitioners. We analyzed the transcripts using an inductive approach and developed a model of how prenatal testing for cotinine could affect the patient-clinician relationship. RESULTS Patients were more likely than clinicians to believe that testing could encourage discussions on tobacco cessation but emphasized that the clinician’s approach to testing was critical. Clinicians feared that testing would negatively affect relationships. CONCLUSIONS Despite having reservations, low-income patients had a surprisingly favorable view of using point-of-care urine testing to promote smoking cessation during pregnancy, which could increase the availability of cessation resources to women who do not disclose their tobacco use to clinicians.
Twin-Twin Transfusion Syndrome and Laser Ablation

Twin-twin transfusion syndrome is a result of placental vascular anastomoses across the placenta, with these anastomoses being either arteriovenous, venoarterial, arterial-arterial, or venoarterial. Twin-twin transfusion syndrome occurs primarily from arteriovenous blood flow from donor placental arteries to recipient placental veins. This imbalance results in the donor twin maintaining normal cardiac function but relative oligohydramnios compared to the recipient twin who has an increased preload, right ventricular hypertrophy, and eventually cardiomyopathy. It may be treated by ligation of the anastomosis fetoscopically with the anesthetic requirement being monitored anesthesia care.
An historical political economy analysis and review of Texas oil and gas well flaring laws and policy

Abstract Flaring (i.e., burning natural gas extracted at an oil or gas well) is an economically wasteful and environmental harmful industrial practice. Although initially banned in Texas, Texas Statewide Rule 32 currently allows oil wells to obtain a permit to legally flare gas. Through a thick description based on archival research, this paper explains: (1) how Texas flaring regulations emerged and weakened over time, (2) why Texas flaring regulations weakened, and (3) the implications of formal policy changes. This paper argues historical political-legal developments created new opportunities for companies to legitimately flare extracted natural gas. As new shale oil and gas development occurs in previously unreachable areas, incentives for immediate profits often outweigh the benefits of investing in the infrastructure and technology necessary to use extracted natural gas for productive purposes. This paper concludes that waste and pollution by oil and gas industry flaring practices can be minimized if state law and administrative code is changed to eliminate legal opportunities for companies to routinely flare natural gas and provide incentives for companies to immediately invest in the technology and infrastructure necessary to collect, store, and/or transport extracted natural gas to be used for energy production.
Phosphoinositides regulate the TRPV1 channel via two functionally distinct binding sites

Abstract Regulation of the heat- and capsaicin-activated Transient Receptor Potential Vanilloid 1 (TRPV1) channel by phosphoinositides is controversial. In a recent cryoEM structure, an endogenous phosphoinositide was detected in the vanilloid binding site, and phosphoinositides were proposed to act as competitive vanilloid antagonists. This model is difficult to reconcile with phosphatidylinositol 4,5- bisphosphate [PtdIns(4,5)P2] being a well established positive regulator of TRPV1. To resolve this controversy, we propose that phosphoinositides regulate TRPV1 via two functionally distinct binding sites. Our molecular dynamics simulations show that phosphatidylinositol (PtdIns) is more stable in the vanilloid binding site, whereas a distinct site responsible for activation is preferentially occupied by PtdIns(4,5)P2. Consistently, we show that in the presence of PtdIns(4,5)P2 in excised patches PtdIns partially inhibited TRPV1 activity induced by low, but not high capsaicin concentrations. In the absence of PtdIns(4,5)P2 on the other hand, PtdIns partially stimulated TRPV1 activity presumably by binding to the activating site. Overall, our data resolve a major controversy in the regulation of TRPV1.
Precarity and the HIV/AIDS pandemic in the Caribbean: Structural stigma, constitutionality, legality in development practice.

The social stigma of sexual immorality is inscripted in constitutions, laws, and statutes in the Caribbean and justified and legitimated through references to Christian doxa. This induces forms of ...
Multidisciplinary Team Management in Heart Failure: Worth it? A Middle-Eastern Experience

Background In recent years, there has been an emphasis on multidisciplinary team (MDT) care of the heart failure (HF) patient. A dedicated HF MDT was created on the 1stof January 2017 at Cleveland Clinic Abu Dhabi; consisting of HF cardiologists, clinical pharmacists and HF nurses. This study aims to assess the impact of a dedicated HF MDT on the mortality, length of stay and readmission rate in patients who are admitted with acute HF decompensation. Methods A retrospective review of the patients’ charts was conducted. We identified patients who were admitted for acute exacerbation of HF between the years 2015 and 2017. Group 1 consisted of 90 patients who were admitted prior to the creation of the HF MDT, while Group 2 consisted of 94 patients who were admitted after the establishment of the team. The groups were propensity-matched in order to account for any confounding variables between the two patient populations. Results Table 1 shows the baseline characteristics on admission of patients in both Group 1 and Group 2. The majority of patients in both groups had HFrEF. There were no significant differences between the two groups in terms of the baseline characteristics outlined. Table 2 highlights the differences in outcomes between the two groups. After the establishment of the HF MDT, there was a significant decrease in the 30 day readmission rate (25.84 % vs 5.98 %, P Conclusions Management of patients with HF by a dedicated HF MDT in the inpatient and outpatient setting results in a significant reduction in morbidity; with reduced 30-day readmission rates, length of stay in hospital, number of days for follow up post-discharge and the need for inotropic support.
Positive Distractions and Play in the Public Spaces of Pediatric Healthcare Environments: A Literature Review.

Background:A positive distraction is a significant environmental feature that introduces positive feelings by diverting attention from stress or anxious thoughts. Existing research has deemed the a...
Noncontact Multiscale Speckle Contrast Diffuse Correlation Tomography (scDCT) of Deep Tissue Hemodynamics

This paper summarizes our recent progresses in developing and applying an innovative noncontact, multiscale, speckle contrast diffuse correlation tomography (scDCT) for rapid and high-density 3D imaging of tissue blood flow distributions in animals and humans.
Effects of using a variety of kinesthetic classroom equipment on elementary students’ on-task behaviour: a pilot study

The ability for students to maintain attention to classroom instruction is a critical factor for learning because loss of instructional time due to off-task behaviour has negative impacts on academic achievement. Early studies suggest that use of kinesthetic equipment in place of traditional seating in classrooms can improve student on-task behaviour. To date, however, limitations of the kinesthetic classroom research literature include small sample sizes, often without controls, use of a single equipment type (e.g. standing desks or exercise balls) and lack of objective measures of student on-task behaviour. We report a pilot study of the impact of using a variety of kinesthetic equipment in elementary classrooms on objectively-measured student on-task behaviour.
Truth and lies in the Caliphate: The use of deception in Islamic State propaganda:

Deception has a long history in information warfare. Recent technological advances have increased the ability of militants to utilize deception in propaganda, but this subject has not been the focu...
Can Skin Cells Improve Outcomes for Patients With Deep Burns

Early excision and split-thickness skin autografts (STSGs) have become standard care for full-thickness burns, but healing the donor site challenges these patients who are already at metabolic and microbial risks, increasing with the total body surface area (TBSA) burned. Engineered skin substitutes containing 1 or more cellular or acellular components of the epidermis, dermis, or hypodermal components have been designed to function as potential STSG replacements, supplementing the barrier or scaffold functions of lost skin. They have reduced the area of STSG tissue needed, helping to improve mortality and healing of patients with large-area, full-thickness burns. Randomized clinical trials (RCTs) continue to explore new ways to optimize scarring, healing, tissue viability, timing, costs, and infection for patients with full-thickness burns2 or chronic wounds. Results for chronic wounds were often inconclusive, based on small studies using varied standards of care with non-blinded outcome evaluation, but evidence on burns is becoming more compelling. This Evidence Corner reviews recent studies that support further improvement of clinical or patient-centered outcomes for hospitalized patients with deep burn wounds managed with STSGs and autologous cultured epidermal cells5 or non-cultured autologous skin cell suspensions.
Future of dairy farming from the Dairy Brain perspective: Data integration, analytics, and applications

Abstract Data integration is one of the biggest challenges the dairy industry faces nowadays due to increased number of technologies and data overflow at the farm. Here we review the current situation of precision dairy farming technologies that use integrated data and its application on the management decision process at the dairy farm. The most common data connections were those from activity monitors, dairy herd improvement records, herd management, and milking recordings. Algorithms used can be defined in general as artificial intelligence and machine learning approaches. Most of the 22 revised papers, research or review, demonstrated that applying different algorithms to integrated data provides additional and complementary insights to improve decision-making tools and therefore enhance economic, management and animal welfare, and hence the sustainability of dairy farms. All revised studies acknowledge the importance of live data integration to develop relevant decision support tools to improve decision making.
Risk of Drug Overdose Mortality for Island-Born and US-Born Puerto Ricans, 2013–2019

In the United States (US), individuals of Puerto Rican heritage die of drug overdoses at higher rates than other Hispanic groups or non-Hispanic Whites; yet, little is known about the extent to which drug overdose mortality affects island-born, versus US-born, Puerto Ricans. The distinction between Puerto Rican-born and US-born provides a starting point for culturally tailored services and interventions, as place of birth often informs language preferences and cultural identifications. Therefore, this study analyzed 2013–2019 death certificate data from the National Center for Health Statistics for 415,111 US deaths attributed to drug overdose. Drug overdose deaths were compared for island-born Puerto Ricans (N=3516), US-born Puerto Ricans (N=4949), and individuals not of Puerto Rican heritage (N=406,646). Drug overdose mortality rates, including age-specific and directly age-standardized rates, were calculated for each subgroup using population estimates from the US Census Bureau’s American Community Survey. Results indicated that age-adjusted drug overdose mortality rates over the period of 2013–2019 were significantly higher for island-born than US-born Puerto Rican men (46.8 versus 34.6, per 100,000), with rates in both groups significantly higher than for men not of Puerto Rican heritage (24.0 per 100,000). For women, in contrast, drug overdose mortality rates were lower for island-born than US-born Puerto Ricans (8.6 versus 11.1, per 100,000). Within stateside Puerto Rican communities, island-born men experience a disproportionate burden of drug overdose mortality, necessitating targeted, culturally appropriate interventions built around the specific norms, circumstances, and lived experiences shared by Puerto Rican migrants who use drugs.
Phases of QCD at High Baryon Density

We review recent work on the phase structure of QCD at very high baryon density. We introduce the phenomenon of color superconductivity and discuss how the quark masses and chemical potentials determine the structure of the superfluid quark phase.We comment on the possibility of kaon condensation at very high baryon density and study the competition between superfluid, density wave, and chiral crystal phases at intermediate density.
Improving the stability of bridge column rebar cages during construction

Rebar cages are the skeletons of reinforced concrete columns formed by connecting the longitudinal to the transverse reinforcement with tie wire connections. The collapse of several bridge rebar cages recently showed the need to establish guidelines to enhance the lateral stability of these temporary structures. The results of experimental and analytical studies on the stability of bridge column rebar cages are presented in this paper. An experimental investigation was conducted on two full-scale rebar cages to determine their lateral behavior and to calibrate nonlinear computational models. Using these calibrated models, the effects of various cage parameters on the lateral stability of rebar cages were investigated. Based on this investigation, it was concluded that the internal bracings provide the significant component of the cage lateral stiffness and strength. Guidelines to improve the lateral stability of column rebar cages are proposed.
GENDER AND SPOUSAL VIOLENCE: A TEST OF SOCIAL CONTROL AND POWER-CONTROL THEORIES

This research will provide an explanation of spousal violence that previously has been lacking in the family violence literature--a social control approach. This research tests the hypothesis that those with stronger bonds to society will be less likely to engage in Spousal violence. Furthermore, this research will incorporate the role that family structures have in stratifying social control for males and females by testing power-control theory. This theory suggests that women from egalitarian households of origin will be more likely to commit wife to husband violence than those from patriarchal households. Results derived from log it models provide partial support for social control theory; however, there is a lack of evidence to support power-control theory's explanation of wife to husband violence.
Using Cost-Sensitive Learning to Determine Gene Conversions

Gene conversion, a non-reciprocal transfer of genetic information from one sequence to another, is a biological process whose importance in affecting both short-term and long-term evolution cannot be overemphasized. Knowing where gene conversion has occurred gives us important insights into gene duplication and evolution in general. In this paper we present an ensemble-based learning method for predicting gene conversions using two different models of reticulate evolution. Since detecting gene conversion is a rare-class problem, we implement cost-sensitive learning in the form of a generated cost matrix that is used to modify various underlying classifiers. Results show that our method combines the predictive power of different models and is able to predict gene conversion more accurately than any of the two studied models. Our work provides a useful framwork for future improvement of gene conversion predictions through multiple models of gene conversion.
Preliminary Findings on the Effects of Self-Referring and Evaluative Stimuli on Stimulus Equivalence Class Formation.

Thirty-two subjects completed 2 stimulus equivalence tasks using a matching-to-sample paradigm. One task involved direct reinforcement of conditional discriminations designed to produce derived relations between self-referring stimuli (e.g., me, myself, I) and positive evaluation words (e.g., whole, desirable, perfect). The other task was designed to produce derived relations between self-referring stimuli and negative evaluation wordls (e.g., unworthy, flawed, inadequate). Performance on each task was recorded via response latency and percent correct. Prior to completion of the equivalence tasks, subjects completed 2 self-report measures: the Outcome Ouestionnaire-45 (OQ-45) and the Rosenberg Self-Esteem Scale (RSE). Subjects were divided into groups based on their OQ-45 score (high or low distress) and RSE score (high or low self-esteem). Significant differences in percent correct were found between both the OQ-45 groups and the RSE groups. Subjects who reported high distress and a negative sense of self made significantly more errors on the tests for equivalence for the task that required matching self-referential stimuli with positive evaluation words.
A Technique for Quantitatively Measuring Microstructurally Induced Ultrasonic Noise

In ultrasonic inspections of aircraft engine components, the detectability of critical defects can be limited by grain noise. This is likely to be the case for subtle defects, such as hard-alpha-phase inclusions in titanium alloys, where the difference between the acoustic impedances of the defect and host is small. A sound quantitative description of grain noise in such alloys is essential for accurate estimates of flaw detection reliability. In this work we present a method for quantifying backscattered grain noise by using positional averaging to determine the root-mean-squared (rms) noise level. The measured noise level will depend on details of the measurement system, as well as on inherent material properties of the alloy. We present a preliminary model of the noise measurement process which accounts for system effects, and we compare its predictions with experiment. We then indicate how the rms noise data can be processed to extract a factor which parameterizes the inherent noise severity independent of the measurement process.
8 Stimulus classes and the untrained acquisition of stimulus functions

Publisher Summary The chapter discusses stimulus classes and the untrained acquisition of stimulus functions. The relation between stimulus classes and the untrained acquisition or emergence of stimulus function is interesting and complex. However, one of the problems in interpreting and integrating the stimulus class literature is that there is an inconsistent terminology for talking about stimulus classes. The other problem is the identification of the prerequisites for the formation of stimulus classes and the variables that control their union. The stimulus classes were distinguished among three types of classes: (1) stimulus classes, (2) functional equivalence classes, and (3) stimulus equivalence classes (Dougher and Markham). The chapter provides a conceptual scheme for integrating the various findings from the stimulus class literature and identifies the classes of variables that may shed light on the relevant issues in the field. Untrained acquisition of stimulus function is one of the most interesting findings to emerge from the recent and growing body of research on stimulus classes, and it is the primary topic of this chapter.
Experiential Learning In An Organizational Leadership Program

This paper is a case study of an experiential learning process in a research methods course. All students work together to complete a research project pertaining to their graduate program.
A network of fast-spiking cells in the neocortex connected by electrical synapses.

Encoding of information in the cortex is thought to depend on synchronous firing of cortical neurons1,2. Inhibitory neurons are known to be critical in the coordination of cortical activity3,4,5, but how interaction among inhibitory cells promotes synchrony is not well understood4,6,7,8,9,10,11,12. To address this issue directly, we have recorded simultaneously from pairs of fast-spiking (FS) cells, a type of γ-aminobutyric acid (GABA)-containing neocortical interneuron13. Here we report a high occurrence of electrical coupling among FS cells. Electrical synapses were not found among pyramidal neurons or between FS cells and other cortical cells. Some FS cells were interconnected by both electrical and GABAergic synapses. We show that communication through electrical synapses allows excitatory signalling among inhibitory cells and promotes their synchronous spiking. These results indicate that electrical synapses establish a network of fast-spiking cells in the neocortex which may play a key role in coordinating cortical activity.
Proximity effect in Cu-Nb-Sn composites

Heat capacities have been measured in the presence of magnetic fields for Cu-Nb and Cu-Nb/sub 3/Sn in situ composites in order to determine the size of the superconducting pair potential which is induced in the normal Cu region as a function of magnetic field. For the Cu-Nb composites the induced pair potential is found to be about 0.35 MeV in zero field, in agreement with de Gennes boundary conditions. With the application of a magnetic field, the energy gap declines quickly and above about 17 mT the Cu behaves as a gapless superconductor. A family of life-time broadened density of states which gives the measured C/sub es/(Cu) is calculated based on the relation between the entropy S and density of states N(..omega..) derived for superconductors doped with paramagnetic impurities. Similar results are found in Cu-Nb/sub 3/Sn composites.
Multicenter trial validation for quantitative analysis of same-day rest-stress technetium-99m-sestamibi myocardial tomograms

UNLABELLED The accuracy of an automated quantitative analysis of same-day rest/stress 99mTc sestamibi SPECT images for detection and localization of coronary artery disease (CAD) was assessed in a multicenter trial consisting of 161 patients from 7 different clinical sites utilizing various camera computer systems. METHODS Of the 161 patients, 102 had angiographically documented coronary artery disease, 22 had normal coronary arteriograms, and 37 had a low (< 5%) likelihood of coronary artery disease based on their age, sex, symptoms and the results of their exercise electrocardiograms. The patients were studied using previously optimized image acquisition and processing protocols. An additional population consisting of 45 patients with single-vessel disease were evaluated to determine the optimal criteria for detection of CAD. RESULTS The quantitative analysis method was associated with an overall sensitivity of 87%, specificity of 36%, and normalcy rate (true negative rate in the low likelihood patients) of 81%. Sensitivity for overall detection of disease was similar (90%) in patients with and without myocardial infarction (90% versus 89%). The sensitivities and specificities for identification of disease in individual coronary arteries were, respectively, 69% and 76% for LAD, 70% and 80% for LCX, and 77% and 85% for RCA. CONCLUSION The results of this study demonstrate that the new objective quantitative method for analysis of same-day rest/stress 99mTc sestamibi SPECT images is accurate for detection and localization of CAD and correlates highly with expert visual interpretation.
Spalling and Cracking in Alumina by Compression

Crack damage produced by compressive loads in a dense alumina ceramic was studied with a replication technique that recorded damage done to the specimen's surface. The characteristics of the spalling produced in an externally pressurized, tubular specimen were evaluated at twelve stress levels up to failure. The study revealed that crack extension begins at a compressive stress approximately one quarter of that required to cause failure and that the amount of crack damage increases greatly as the failure stress is approached. The nature of the spalled particles and the mechanisms of spalling are discussed. Mechanisms of compressive failure are suggested.
Hydrobiology and organic production in a marl lake of Kashmir Himalayan Valley

L. Naranbagh (alt. 1587 m) is a polymictic, shallow marl lake in the flood-plain valley of Kashmir, India. Macrofloral affinities resemble ‘Potamogeton Type’ of Forsberg (1965) with alkaline waters, not rich in phosphorus. CaCO3 precipitation coupled with decline in Ca2+ and alkalinity values are characteristic of the lake. Fluctuations in Mg2+, Na+, K+, and Cl− were relatively conservative. The levels of PO inf4 sup3− -P and NO inf3 sup− -N indicate moderate fertility of the lake water. Persistence of a summer-autumn planktonic algal pulse is related to favourable irradiance, high water temperatures, and increased photosynthetic efficiency values. The most striking seasonality in photosynthetic rates (m−2 h−1) between winter minimum (Σ3 mg Cassim) and summer maximum (Σ75.4 mg Cassim) is determined by mainly climatic changes. Energy flow gave annual phytoplankton production of 51.95 × 102 KJ m−2 for the ecosystem. The nutrient levels and productivity rates suggest mesotrophic status of L. Naranbagh in classic oligoeutrophic classification of lake types.
Recent results in auroral-zone scintillation studies

Abstract Nighttime data from the Defense Nuclear Agency's Wideband satellite have consistently shown a pronounced scintillation enhancement at the point where the propagation vector lies within the local L-shell. Simultaneous observations at two well-separated stations and spaced-receiver measurements have shown that this feature is caused by a latitudinally narrow, unstable F-region ionization enhancement that produces sheet-like intermediate-scale structures. A more detailed characterization of the source region has been derived from simultaneous measurements from the TRIAD satellite and the Chatanika radar. The source region is typically convecting southward, whereby the poleward gradient at its southern boundary is stable to the gradient-drift instability. Thus, Ossakow and Chaturvedi (1979) postulated the current-convective instability as a source mechanism. Birkeland currents, when sufficiently intense, can destabilize a region that is otherwise stable to the gradient-drift instability. The sheet-like anisotropy of the irregularities is perhaps the most intriguing feature of the instability. Two mechanisms have been postulated to explain it. This paper reviews the development and current status of our understanding of this recently discovered high-latitude instability.
A double quantum 129Xe NMR experiment for probing xenon in multiply-occupied cavities of solid-state inclusion compounds

A method is presented for detecting multiple xenon atoms in cavities of solid-state inclusion compounds using 129Xe double quantum NMR spectroscopy. Double quantum filtered 129Xe NMR spectra, performed on the xenon clathrate of Dianin’s compound were obtained under high-resolution Magic-Angle Spinning (MAS) conditions, by recoupling the weak 129Xe–129Xe dipole–dipole couplings that exist between xenon atoms in close spatial proximity. Because the 129Xe–129Xe dipole–dipole couplings are generally weak due to dynamics of the atoms and to large internuclear separations, and since the 129Xe Chemical Shift Anisotropy (CSA) tends to be relatively large, a very robust dipolar recoupling sequence was necessary, with the symmetry-based SR26114 dipolar recoupling sequence proving appropriate. We have also attempted to measure the 129Xe–129Xe dipole–dipole coupling constant between xenon atoms in the cavities of the xenon–Dianin’s compound clathrate and have found that the dynamics of the xenon atoms (as investigated with molecular dynamics simulations) as well as 129Xe multiple spin effects complicate the analysis. The double quantum NMR method is useful for peak assignment in 129Xe NMR spectra because peaks arising from different types of absorption/inclusion sites or from different levels of occupancy of single sites can be distinguished. The method can also help resolve ambiguities in diffraction experiments concerning the order/disorder in a material.
Effect of mutations in Pneumocystis carinii dihydropteroate synthase gene on outcome of P carinii pneumonia in patients with HIV-1: a prospective study

Summary Background Investigators have reported that patients infected with Pneumocystis carinii containing mutations in the DHPS (dihydropteroate synthase) gene have a worse outcome than those infected with P carinii containing wild-type DHPS . We investigated patients with HIV-1 infection and P carinii pneumonia to determine if DHPS mutations were associated with poor outcomes in these patients. Methods We compared presence of mutations at the DHPS locus with survival and response of patients to co-trimoxazole or other drugs. Findings For patients initially given co-trimoxazole, nine (14%) of 66 with DHPS mutant died, compared with nine (25%) of 36 with wild type (risk ratio=0·55 [95% CI=0·24–1·25]; p=0·15). Ten (15%) of 66 patients with a DHPS mutant did not respond to treatment, compared with 13 (36%) of 36 patients with the wild type (0·42 [0·20–0·86]; p=0·02). For patients aged 40 years or older, four (14%) of 29 with the mutant and nine (56%) of 16 with the wild type died (0·25 [0·09–0·67]; p=0·005). Interpretation These results, by contrast with those of previous studies, suggest that patients with wild-type P carinii do not have a better outcome than patients with the mutant when given co-trimoxazole. Our results suggest that presence of a DHPS mutation should be only one of several criteria guiding the choice of initial drug treatment of P carinii pneumonia in patients with HIV-1 infection.
Lessons learned in Liberia: preliminary examination of the psychometric properties of trust and teamwork among maternal healthcare workers

Post-conflict Liberia has one of the fastest growing populations on the continent and one of the highest maternal mortality rates among the world. However, in the rural regions, less than half of all births are attended by a skilled birth attendant. There is a need to evaluate the relationship between trained traditional healthcare providers and skilled birth attendants to improve maternal health outcomes. This evaluation must also take into consideration the needs and desires of the patients. The purpose of this pilot study was to establish the validity and reliability of a survey tool to evaluate trust and teamwork in the working relationships between trained traditional midwives and certified midwives in a post-conflict country. A previously established scale, the Trust and Teambuilding Scale, was used with non- and low-literate trained traditional midwives (n=48) in rural Liberia to evaluate trust and teamwork with certified midwives in their communities. Initial results indicated that the scale and response keys were culturally inadequate for this population. A revised version of the scale, the Trust and Teamwork Scale – Liberia, was created and administered to an additional group of non- and low-literate, trained traditional midwives (n=42). Exploratory factor analysis using Mplus for dichotomous variables was used to determine the psychometric properties of the revised scale and was then confirmed with the full sample (n=90). Additional analyses included contrast validity, convergent validity, and Kuder-Richardson reliability. Exploratory factor analysis revealed two factors in the revised Trust and Teamwork Scale – Liberia. These two factors, labeled trust and teamwork, included eleven of the original eighteen items used in the Trust and Teamwork Scale and demonstrated contrast and convergent validity and adequate reliability. The revised scale is suitable for use with non- and low-literate, trained traditional midwives in rural Liberia. Continued cross-cultural validation of tools is essential to ensure scale adequacy across populations. Future work should continue to evaluate the use of the Trust and Teamwork Scale – Liberia across cultures and additional work is needed to confirm the factor structure.
Effect of limiting snack food variety on long-term sensory-specific satiety and monotony during obesity treatment.

Abstract Limiting meal variety decreases hedonic ratings of eaten foods more so than non-eaten foods, demonstrating sensory-specific satiety. Exposure to a food over time decreases the food's hedonic ratings, indicating monotony. The effect of limiting food group variety over time on long-term sensory-specific satiety and monotony is unknown. Thirty overweight adults were randomized to one of two 8-week behavioral weight loss interventions. One condition limited snack food intake to one chosen snack food (reduced variety), while the other limited snack food intake to
ALTERNATE INTEGRAL-FORMULATION METHOD FOR PREDICTING ACOUSTIC RADIATION

Algorithms for an alternative integral-formulation method (AIM) are developed for predicting acoustic radiation from an arbitrary source in a free field. The main advantages of these algorithms are that the solution is always unique and the efficiency in numerical computations is very high. The input data to these algorithms consist of the normal and tangential components of the particle velocities that are specified on a hypothetical surface enclosing the source, and output data are the acoustic quantities that include the acoustic pressure, particle velocity, and acoustic intensity on and beyond the enclosure. To speed up the numerical computations, the Dijistra algorithm is adopted that searches automatically the shortest path between two neighboring nodes in carrying out line integral. Experiments in both interior and exterior regions are conducted, and the predicted acoustic pressure is checked against the benchmark value measured at the same location. The efficiency of AIM is examined and compared with that of conventional boundary element method (BEM) based Helmholtz integral formulations.
Columbus in the Twilight Zone: Bruce Ackerman's “Discovery” of the Constitution

If Bruce Ackerman is right, the most contentious issues of modern constitutional theory have been fought out on a map that misses the most significant features of our political landscape. For the last decade constitutional theorists have hotly debated whether the U.S. Constitution is best understood through one or the other of an amazing variety of philosophical traditions including Lockean liberalism, Kantean ethics, hermeneutic theory, and the Atlantic Republican tradition. On Ackerman's account these theorists have failed to appreciate the uniquely American innovations in democratic theory and practice, as they strived mightily to fit them into the glass slipper of European political theory. In We the People, and two more promised volumes, Ackerman sets out to redescribe our constitutional past and reinterpret our present impasses in light of his discovery of America's great invention in 1787-"dualist democracy." Like Columbus's "discovery" of America, the five hundredth anniversary of which is being celebrated and critiqued this year, Ackerman's self-pronounced "discovery" of the Constitution raises troubling questions. How do we come to grips with our dependence on a past we cannot help but reshape by rethinking? How can we escape the reproduction of the processes of domination that marked the past? To his great credit Ackerman wrestles with these problems. The continent he claims for us is empowering in its rediscovered
A refractive focusing lens system for small-angle neutron scattering

Simple neutron optics measurements have been performed using optical-quality concave lenses as a function of neutron wavelength on a 30 m SANS instrument. The variation in the width of the beam spot on the detector at wavelengths different from the focused condition has been observed. The movement of the beam on the detector when the centerline of the lens combination is shifted from the incident-beam centerline has also been observed. These results are compared with theoretical predictions.
The future beckons [electric power industry]

This paper discusses the challenges that the US electric power industry has to face to continue to maintain the stable, reliable, and efficient system over the next few years. These challenges include an aging transmission system suffering from substantial underinvestment, the need for a regulatory framework that will spur independent investment, ownership and management of the nation's grid, and an aging workforce and the need for a succession plan to ensure the existence of the next generation of technical expertise in the industry. Through the efforts of many and by working together through concerned organizations, the industry can move forward to the benefit of the public and the US as a whole.
The chemistry of stratospheric ozone: its response to natural and anthropogenic influences☆

Abstract The current rapid changes in the composition of the atmosphere reflect both the metabolism of the biosphere and the broad range of influencing human activities. However, the only known sources of CFCs are industrial. In predicting future changes in ozone depletion and global warming it is necessary to understand the role of the biosphere in regulating emissions as well as future industrial emissions. This paper discusses theoretical predictions and trends in global ozone concentrations from 1969–1986. Antarctic and Arctic ozone trends and the global implications of the Antarctic ozone hole are described in detail. It is concluded that even if the control measures of the Montreal Protocol are implemented by all nations, the atmospheric abundance of chlorine will at least double during the next few decades. Future global ozone depletion could be larger than originally predicted because the PSC-induced chemical reactions that cause ozone depletion were not included in the stratospheric ozone assessment models on which the Montreal Protocol was based. To return the Antarctic ozone layer to its natural state will require very strong measures, including a complere phase out of all fully halogenated CFCs, halons, carbon tetrachloride and methyl chloroform, as well as careful use of HCFC substitutes.