cssi/SciSciGPT-SciSciNet huggingface dataset:
A hidden Markov model of customer relationship dynamics

This research models the dynamics of customer relationships using typical transaction data. Our proposed model permits not only capturing the dynamics of customer relationships, but also incorporating the effect of the sequence of customer-firm encounters on the dynamics of customer relationships and the subsequent buying behavior. Our approach to modeling relationship dynamics is structurally different from existing approaches. Specifically, we construct and estimate a nonhomogeneous hidden Markov model to model the transitions among latent relationship states and effects on buying behavior. In the proposed model, the transitions between the states are a function of time-varying covariates such as customer-firm encounters that could have an enduring impact by shifting the customer to a different (unobservable) relationship state. The proposed model enables marketers to dynamically segment their customer base and to examine methods by which the firm can alter long-term buying behavior. We use a hierarchical Bayes approach to capture the unobserved heterogeneity across customers. We calibrate the model in the context of alumni relations using a longitudinal gift-giving data set. Using the proposed model, we probabilistically classify the alumni base into three relationship states and estimate the effect of alumni-university interactions, such as reunions, on the movement of alumni between these states. Additionally, we demonstrate improved prediction ability on a hold-out sample.
Attachment, Mentalization, and Criterion B of the Alternative DSM-5 Model for Personality Disorders (AMPD).

The mentalization theory posits that interpersonal difficulties and maladaptive personality traits develop from an insecure attachment pattern with one’s caregiver and corresponding deficits in mentalizing—the ability to understand others’ and one’s own mental states. Mentalizing deficits have been theorized as the basis for all psychopathology, with the paradigmatic case being Borderline Personality Disorder. Nevertheless, developments in the personality field indicate personality pathology is best represented dimensionally, and such a proposal was outlined by the Alternative DSM-5 Model for Personality Disorders (AMPD). Despite evidence linking the mentalization theory to personality disorders, however, it has yet to be applied to Criterion B of the AMPD. The aim of the present study was to evaluate the moderating role of mentalizing in the relation between attachment and Criterion B maladaptive trait function in a sample of undergraduates. We hypothesized a model in which: (1) attachment insecurity would be positively associated with the Negative Affectivity, Antagonism, and Disinhibition personality domains; (2) mentalizing ability would be negatively associated with these domains; and, (3) there would be an interaction effect between attachment and mentalizing when predicting these same domains. Personality domains were measured dimensionally via the Personality Inventory for DSM-5 (PID-5-SF), while the dependence and avoidance domains of attachment were assessed via the Relationship Questionnaire (RQ). Mentalizing ability was tapped by the Movie for the Assessment of Social Cognition (MASC). The AMPD personality domains and trait facets were examined as dependent variables; attachment dependence, attachment avoidance, and overall mentalizing ability were entered as independent variables; and interaction terms between mentalizing and each attachment dimension were used to test moderation via MANCOVAs. Consistent with expectations, results indicated overall mentalizing moderated the relation between attachment avoidance and Negative Affectivity. Posthoc analyses revealed similar effects on the relations between attachment avoidance and the Emotional Lability, Hostility, and Perseveration trait facets; however, there were no significant moderation findings related to attachment dependence. These results support the mentalization theory’s application to Criterion B of the AMPD, particularly in relation to the links between Negative Affectivity and borderline-related traits, and encourage future research of dimensional maladaptive personality. They further bolster support for understanding maladaptive personality as a dimensional construct.
Surgical Management of Tubo-Ovarian Abscesses That Failed Percutaneous Drainage

Study Objective Report outcomes in the management of tubo-ovarian abscesses (TOA) initially managed with percutaneous drainage. Design Retrospective chart review. Setting Tertiary University-affiliated Medical Center. Patients or Participants Patients who underwent percutaneous drain placement for TOA from 2003 to 2020 were included. Percutaneous drainage CPT codes were used to retrieve patient cases. Charts were subsequently reviewed manually. Cases with retrospective diagnoses of: Endometriosis or non-genital etiology of TOA were excluded. Interventions percutaneous drainage. Measurements and Main Results Sixty-six patients were identified, nine met exclusion criteria, and 57 were analyzed. Percutaneous drainage was successful in 42 patients, while surgery was ultimately required in 15 cases. Of 15 surgical cases only 4 occurred during the initial admission, whereas 11 were delayed and performed due to recurrence of TOA (5), persistence of symptomatic mass (3), or development of chronic pelvic pain (3). Three patients underwent salpingo-oophorectomy. Eight underwent hysterectomy with unilateral or bilateral salpingo-oophorectomy. All but one patient who underwent delayed intervention had it within 1 year of initial presentation. Conclusion Percutaneous drainage of TOA is initially successful in 93% of patients, however ultimately 26% of patients ultimately require surgical intervention.
An integrative review of literature: virtual exchange models, learning outcomes, and programmatic insights

This integrative review explores English language publications to determine trends present in Virtual Exchange (VE) research over a span of ten years. The review presents a brief introduction to VE, highlights key scholars in the field, and describes various VE models. In addition, learning outcomes and programmatic insights present in current scholarship are categorized and examined. This review can serve as a helpful tool for practitioners new to VE, as well as for scholars interested in expanding the VE research field.
Asymmetric synthesis of functionalized 2,3-dihydrobenzofurans using salicyl N-phosphonyl imines facilitated by group-assisted purification (GAP) chemistry

In this work, we present a strategy for the preparation of functionalized 2,3-dihydrobenzofuran derivatives via the Cs2CO3-catalyzed domino annulation of enantiopure chiral salicyl N-phosphonyl imines with bromo malonates, which offers an avenue for the construction of 2,3-dihydrobenzofurans. Nineteen examples were synthesized in impressive chemical yields and diastereoselectivity. The products were purified simply by washing the crude mixtures with hexanes following group-assisted purification chemistry/technology to bypass traditional separation methods which often result in a loss of product. The absolute configuration was unambiguously assigned by X-ray structural analysis.
(Dis)citizenship constructed in same-sex wedding narratives

Abstract Citizenship as institutional participation includes marriage and weddings, and the lack of rights to legal marriage constructs dis-citizenship. Not only are hierarchies reproduced through language, but individuals who are affected by such processes negotiate (dis)citizen-identities through talk. Through sociolinguistic interviews with couples about their weddings, this research examines that negotiation as two same-sex couples construct identities that produce authenticity and legitimacy for their participation in officially recognized couplehood. Mark and Javier (married in 2010) index social, financial, and legal constraints surrounding their legally-recognized wedding, and Barb and Heidi (married in 2000) index tradition, thus constructing legitimacy despite their ceremony that was not legally recognized. Both couples navigate constraints and possibilities in the ways they linguistically construct their coupled identities in these conversations about their weddings, thus producing (dis)citizenship.
A semi-autonomous wheelchair with helpstar

This paper describes a semi-autonomous wheelchair enabled with "HelpStar" that provides a user who is visually impaired with mobility independence. Our "HelpStar" enabled semi-autonomous wheelchair functions more like a personal assistant, allowing much greater user independence. When the user finds themself in an unforeseen circumstance, the "HelpStar" feature can be activated to allow a remote operator to use Virtual Reality technologies to provide helpful navigational instructions or to send commands directly to the wheelchair. This paper demonstrates the successful integration of assistive technologies that allow a person who is visually impaired and using a wheelchair to navigate through everyday environments.
Cytokine Stimulation of Nitric Oxide Formation and Differential Regulation in Hepatocytes and Nonparenchymal Cells of Endotoxemic Rats

Some disease processes in which increased endotoxin and cytokine levels exist (e.g., sepsis and infantile diarrhea) are also associated with increased levels of blood nitrates, the stable and products of nitric oxide. Available evidence suggests that the effects of an endotoxic environment, with its attendant complex cytokine networks, on liver function are mediated in part by modulation of hepatic nitric oxide synthesis. This hypothesis was tested by means of studying nitric oxide formation and its regulation in liver parenchymal and nonparenchymal cells of rats that had been continuously infused with endotoxin for 30 hr. Hepatocytes of such rats responded to in vitro stimulation for 20 hr by single cytokines, tumor necrosis factor, interleukin-1s and interferon-γ with enhanced nitric oxide formation. In combination, interferon-γ and endotoxin had greater synergistic effect on hepatocytes than did tumor necrosis factor and endotoxin. Kupffer cells of these endotoxic rats responded to 20 hr of interferon-γ stimulation with the same enhanced nitric oxide formation we documented previously for endotoxin. Potentiation of the effect, through combination of endotoxin and interferon-γ, was not as marked as it was with hepatocytes. Challenge of Kupffer cells with tumor necrosis factor or interleukin-1s evoked no response. Hepatocytes and Kupffer cells of time-matched, saline solution-treated rats were unresponsive to endotoxin or cytokine stimulation. Small quantities of nitric oxide were produced by endothelial cells spontaneously; this production was somewhat enhanced in cells of the endotoxin-infused rats by a 20-hr in vitro endotoxin challenge. Studies with inhibitors suggest that enhanced nitric oxide formation by endotoxic hepatocytes and Kupffer cells in response to in vitro endotoxin stimulation is differentially regulated. Our findings indicate modulation of nitric oxide generation by cytokines in vitro in various liver cell types of endotoxic rats. A similar scenario may exist in vivo because of the prevailing inflammatory response to endotoxin administration. (Hepatology 1994;19:217–228).
Two-Dimensional Hidden Markov Model for Classification of Continuous-Valued Noisy Vector Fields

In this paper we present a statistical model with a nonsymmetric half-plane (NSHP) region of support for two-dimensional continuous-valued vector fields. It has the simplicity, efficiency, and ease of use of the well-known hidden Markov model (HMM) and associated Baum-Welch algorithms for time-series and other one-dimensional problems. At the same time it is able to learn textures on a two-dimensional field. We describe a fast approximate forward procedure for computation of the joint probability density function (pdf) of the vector field as well as an approximate Baum-Welch algorithm for parameter reestimation. Radar and sonar applications include classification of two-dimensional fields such as range versus azimuth or range versus aspect angle data wherein each data point in the field consists of a multi-dimensional feature vector. We test the method using synthetic textures.
Effects of sulphur substituents on the geometries of dipalladium μ-thiolato complexes: Crystal structures of Pd2Cl2(μ-Cl)(μ-SR)(PMe3)2 (R Me, t-Bu and Ph) and Pd2Cl2(μ-SPh)2(PEt3)2

Abstract The mono(μ-alkylthiolato) complexes, cis-Pd2Cl2(μ-Cl)(μ-SR)(PMe3)2 (R  Me, 1; t-Bu, 2) are obtained as the exclusive products of the reaction of acetone solutions of trans-[PdCl(μ-Cl)(PMe3)]2 with the corresponding thiols at 25°C, whereas reaction with stoichiometric amounts of thiophenol gives mixtures of cis-Pd2Cl2(μ-Cl)(μ-SPh)(PMe3)2 (3) and trans-Pd2Cl2(μ-SPh)2(PMe3)2 (5). Reaction of trans-[PdCl(μ-Cl)(PR3)]2 with thiophenol in a 1 : 2 stoichiometry gives exclusively trans-Pd2Cl2(μ-SPh)2(PR3)2 (R = Et, 4; Me, 5). The molecular structures of 1, 2, 3·CH2Cl2 and 4 have been determined by X-ray diffraction. Complexes 1 and 2 have non-planar geometries with dihedral angles of 140 and 146°, respectively, between the coordination planes of the palladium atoms. By contrast, the μ-arylthiolato complexes are planar with dihedral angles of 180° between the coordination planes of the palladium atoms. The PdS bond distances 2.262(2)–2.272(2) A in complexes 1 and 2 are significantly shorter than the PdS distances in 3, 2.288(2) and 2.301(2) A, indicating enhanced metal-sulphur bonding in the alkylthiolato complexes. The bent geometries of the alkylthiolato complexes as well as the dichotomy of cis and trans phosphine geometries preferred by M2Cl2(μ-SR)2(PR′3)2 (M = Pd, Pt) alkylthiolato and arylthiolato complexes, respectively, are discussed in view of the enhanced sulphur-metal donor interactions in the alkylthiolato complexes. The isolation of mono(μ-thiolato) complexes from the reaction of trans-[PdCl(μ-Cl)(PMe3)]2 with alkylthiols and not arylthiols is also accounted for by the additional stabilization of the metal-sulphur bonds in the alkylthiolato complexes. Crystallographic data : for 1, orthorhombic, Pbc21, Z = 4, a = 11.630(6), b = 11.667(3), c = 12.816(4) A, V = 1739(1) A3, ϱcalc. = 1.980 g cm−3; for 2, orthorhombic, P21cn, Z = 4, a = 8.158(3), b = 10.345(3), c = 24.106(6) A, V = 2035(1) A3, ϱcalc. = 1.830 g cm−3; for 3·CH2Cl2, monoclinic C2/2, Z = 8, a = 27.38(1), b = 11.477(9), c = 16.506(7) A, β = 124.12(3)°, V = 4294(4) A3, ϱcalc. = 1.924 g cm−3; for 4, triclinic P 1 , Z = 2, a = 8.694(5), b = 9.570(6), c = 10.203(7) A, α = 68.72(5), β = 76.86(5), γ = 85.27(5)°, V = 770.3(8) A3, ϱcalc. = 1.592 g cm−3.
Effect of implementing instructional videos in a physical examination course: an alternative paradigm for chiropractic physical examination teaching.

OBJECTIVE This study examined the effect of implementing instructional video in ophthalmic physical examination teaching on chiropractic students' laboratory physical examination skills and written test results. METHODS Instructional video clips of ophthalmic physical examination, consisting of both standard procedures and common mistakes, were created and used for laboratory teaching. The video clips were also available for student review after class. Students' laboratory skills and written test results were analyzed and compared using one-way analysis of variance (ANOVA) and post hoc multiple comparison tests among three study cohorts: the comparison cohort who did not utilize the instructional videos as a tool, the standard video cohort who viewed only the standard procedure of video clips, and the mistake-referenced video cohort who viewed video clips containing both standard procedure and common mistakes. RESULTS One-way ANOVA suggested a significant difference of lab results among the three cohorts. Post hoc multiple comparisons further revealed that the mean scores of both video cohorts were significantly higher than that of the comparison cohort (p .05). However, the percentage of students having a perfect score was the highest in the mistake-referenced video cohort. There was no significant difference of written test scores among all three cohorts (p > .05). CONCLUSION The instructional video of the standard procedure improves chiropractic students' ophthalmic physical examination skills, which may be further enhanced by implementing a mistake-referenced instructional video.
African Americans and HIV/AIDS – the epidemic continues: an intervention to address the HIV/AIDS pandemic in the black community.

The Black community continues to be ravished by HIV/AIDS infection despite the marked expenditures utilized to reduce incidence among this cohort. Efforts to produce culturally appropriate programs that work continues to elude officials and HIV/AIDS has become endemic among specific subgroups in this cohort (e.g., Black men who have sex with men). Large-scale prevention programs have not worked and although community-based interventions have proven to be effective in eliciting behavior change, the numbers that they have been producing have not been enough to make a substantial impact on HIV incidence. The purpose of this exploratory article is to rehash how HIV/AIDS infection continues to devastate the African American community in an effort to elicit renewed vigilance in combating the disease in this community, describe the elements that continue to impede prevention and risk reduction efforts, and present a potential framework that may work to decrease incidence in this community. This article presents ...
Fine structure and development of two polyhedrosis viruses

Abstract Some characteristics of two viruses of the Douglas-fir tussock moth are described. Viral development appears to start in the nuclei of infected cells with the formation of tubes believed to be the capsids. Subsequently, the tubes are filled with viral nucleoprotein. Filaments which may be molecules of DNA are illustrated. Objects believed to be defective virus particles, consisting of capsids containing a subnormal quantity of nucleoprotein, are described. The bearing of these observations on the existence of an “intimate membrane” is discussed.
The generalized matching law as a predictor of choice between cocaine and food in rhesus monkeys.

Rationale: The generalized matching law predicts that the relative rate of behavior maintained by different reinforcers will match the relative rate of reinforcement. It has previously been shown that responding maintained by either food deliveries or cocaine injections under concurrent variable-interval (conc VI) schedules is well described by the generalized matching law. However, the generality of this conclusion to the choice between a drug and a non-drug reinforcer has not been well established. Objective: The objective of the present study was to determine the extent to which the generalized matching law could account for choice between cocaine and food. Methods: Four male rhesus monkeys (Macaca mulatta) lever pressed under various pairs of conc VI schedules with food and/or cocaine injection as the maintaining events. Two doses of cocaine (0.025 and 0.05 mg/kg per injection) were selected to provide information about reinforcer magnitude. Results: As has been found in a context of choice between identical reinforcers, the generalized matching law accounted for most behavior. As in earlier studies with identical reinforcers, there was less responding apportioned to the alternative with the greater reinforcement frequency than predicted by the generalized matching law, i.e., undermatching was observed frequently. There was a tendency for more responding to be emitted toward the food alternative when the lower dose of cocaine was available and toward the drug alternative when the higher dose of cocaine was available. Conclusion: These results suggest that, as proposed by the generalized matching law, relative reinforcement rate is an important determinant of choice between a drug and a non-drug reinforcer.
The movement of bound ligands over cell surfaces

Abstract The long range movements of membrane-bound ligands into surface caps and into the pseudopods of phagocytizing cells, the uropods of motile cells and the cleavage furrow of dividing cells appear to be analogous processes. A common mechanism to explain these movements must take into account several new and central observations: ligand-receptor complexes can migrate to regions of existing microfilament accumulation; laser photobleaching studies with fluorescent Con A indicate that ligand-receptor movement occurs unidirectionally; video computer analyses of Con A redistribution show that movement may exceed the maximum rates measured for protein diffusion in membranes. These observations are not consistent with models in which ligand-receptor movement occurs by diffusion or by direct interaction with contractile microfilaments. However, they can be satisfied by a new model that proposes the entrainment of selected membrane determinants on membrane waves directed towards regions such as caps, pseudopodia, uropods or cleavage furrow. These oriented waves are initiated by tension due to asymmetric microfilamentmembrane interaction.
The growth of randomized experiments in policing: the vital few and the salience of mentoring

The population of randomized experiments in policing is used to examine co-author and mentoring relations in the professional network of scholars and assess if experimental criminology is on the path to creating the necessary social capital to promote the use of randomized controlled trials in criminology and criminal justice research. We use systematic review methods to identify the population of policing experiments. Narrative review and descriptive statistics are used to examine the growth of policing experiments over time. Social network analysis techniques are used to analyze and describe the co-authoring and mentoring connections of the scholars responsible for completing policing experiments. We find that the number of policing experiments increased substantially between 1970 and 2011. The growth in policing randomized experiments has been largely generated by a very small number of scholars who account for the bulk of policing experiments and have been very active in mentoring the next generation of experimentalists. Another important factor associated with the rise in policing experiment is the availability of federal funding. Our analysis of policing experiments suggests that the experimental criminology movement is developing the necessary human and social capital to advance the discipline of criminology. However, it is a very small network that could benefit from the addition of new members and increased training and mentoring of graduate students.
The Effects of Aging, Deboning, and Brine Solutions on Japanese Quail (Coturnix coturnix japonica) Tenderness and Cooked Yields,

Abstract Two trials were performed on Coturnix quail carcasses to document the effects of aging and deboning on tenderness of the pectoralis muscle. Carcasses were aged 2 or 24 hr. Half of all carcasses were deboned prior to aging and the rest after the appropriate aging interval. All samples aged before deboning were significantly (P≤.05) more tender than those deboned prior to aging as assessed by Warner-Bratzler and Allo-Kramer shear results of the cooled product. The addition of 2.5% salt to the aging solution further increased tenderness. The toughness associated with deboning the pectoralis major before aging could be partially offset by longer aging times after deboning or using salt or phosphate in the aging solution. The addition of salt to the aging solution also resulted in better cooked yields. The results from this study suggest a minimum aging of 2 hr prior to deboning Coturnix quail carcasses to allow for tenderization to occur.
Advances in reduced-rank adaptive beamforming

In this work we first analyze two methods of finding low rank solutions: Steering Independent Conjugate Gradient (SI-CG) and Steering Dependent Conjugate Gradient (SD-CG). These low-rank beamformers have a rank where the output SINR is maximized and a large drop in the output SINR can occur if the beamformer operates at an improper rank. Indirect Dominant Mode Rejection (IDMR) is proposed wherein one first employs a high-resolution spatial spectrum estimation technique to estimate the directions and powers of the dominant interferers. Subsequently, this information is used to construct an estimate of the signal-free (interference plus noise only) autocorrelation matrix (for a given look-direction.) In this process, any residual correlations between the interferers and the signal arriving from the look-direction due to finite sample averaging is effectively removed. Simulations reveal that IDMR yields a dramatic improvement in output SINR relative to CG and PCI/DMR, even when the latter operate at the optimal rank. In the case of correlated signals IDMR shows not to degrade the output SINR, different from CG and PCI/DMR.
A Laboratory Project on the Theory, Fabrication, and Characterization of a Silicon-On-Insulator Micro-Comb Drive Actuator With Fixed-Fixed Beams

A laboratory course on the theory, fabrication, and characterization of microelectromechanical systems (MEMS) devices for a multidisciplinary audience of graduate students at the University of New Mexico, Albuquerque, has been developed. Hands-on experience in the cleanroom has attracted graduate students from across the university's engineering and science campuses, including students from the Nano-Science and Micro Systems program, itself an interdisciplinary program. This course has been offered yearly for the last four years (since 2007) at the University of New Mexico. In one project from the class, a MEMS actuator is fabricated. This paper details the theory, fabrication steps, and characterization of a silicon-on-insulator (SOI) comb drive actuator that relies on fixed-fixed beams for its restoring force. Discussions include force generation by comb drives and a linear and nonlinear description of the restoring force applied by the fixed-fixed beams. Course assessment data is given from 79 students from three semesters, based on which the effectiveness of the laboratory project is evaluated.
Estimating reservoir parameters from seismic and electromagnetic data using stochastic rock‐ physics models and Markov chain Monte Carlo methods

A Bayesian model is developed to estimate porosity, fluid saturation, and pore pressure in reservoirs using seismic and electromagnetic (EM) data. Within the Bayesian framework, unknown reservoir parameters at each pixel in space are considered as random variables and the co-located geophysical properties (seismic Pand S-wave velocity, density, and electrical conductivity), inverted from seismic and EM measurements, are considered as data. Rock-physics models are derived from borehole logs and are considered as random functions between the reservoir parameters and the geophysical properties. Using Markov chain Monte Carlo (MCMC) methods, many samples of each unknown variable are obtained from the Bayesian model, which subsequently are used to infer the unknown variable (reservoir parameter) as well as its uncertainty. A study, based on borehole data from a site in the Troll field, shows that the developed method is more effective for reservoir parameter estimation than traditional regression methods.
Pod Dehiscence of Soybean: Identification of Quantitative Trait Loci

The dehiscence of pods (shattering) prior to harvest is an undesirable trait of soybean, Glycine max (L.) Merr. Pod dehiscence (PD) is relatively uncommon in modern North American soybean cultivars, but is often observed when unimproved germplasm or the wild species, G. soja Siebold & Zucc., are used as parents to introgress useful genes or to develop genetically diverse breeding populations. In light of the potential for efficient selection using DNA markers, the objective of this study was to identify quantitative trait loci (QTL) that condition resistance to PD. A map of 140 linked restriction fragment length polymorphism (RFLP) markers was constructed using 120 F4-derived lines from a soybean population (Young x PI 416937) that segregated for resistance to PD. These lines were scored for PD on a visual scale of 1 to 10 at both Athens, Georgia, and Windblow, North Carolina, in 1994. Heritability of pod dehiscence was 92%. Associations of marker loci with QTL that condition resistance to PD were tested using homozygous RFLP class means in a single-factor ANOVA. A total of five putatively independent RFLP markers were associated with PD at both locations and in a combined analysis over locations. A single RFLP locus on linkage group J of the USDA/Iowa State University map accounted for 44% of the variation in PD score. Epistasis was observed between one pair of significant marker loci. These results establish the genomic location of one major and a few minor QTL, identify an epistatic interaction, and indicate transgressive segregation which is plausibly the result of susceptibility alleles contributed by the resistant parent.
Non-condon effects in the X→A electronic absorption band system of sulphur dioxide

Abstract The anomalously long bending-mode progressions observed in the X → A absorption band of SO 2 are interpreted as a non-Condon effect due to a large change in OSO angle between the coupled A and B states.
Higher levels of coated-platelets are observed in patients with subarachnoid hemorrhage but lower levels are associated with increased mortality at 30 days.

Abstract Background Coated-platelets are procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin. Coated-platelet levels are elevated in non-lacunar ischemic stroke compared to either lacunar stroke or controls. In contrast, coated-platelet levels are decreased in spontaneous intracerebral hemorrhage (ICH) and inversely correlated with bleed size. We now report the first investigation of coated-platelets in patients with subarachnoid hemorrhage (SAH). Methods Coated-platelet levels were determined in 40 consecutive patients with spontaneous SAH and in 40 controls. Results are reported as percent of cells converted to coated-platelets. Mortality at one month was recorded for all patients. Results Coated-platelet levels (mean ± SD) were significantly higher in SAH patients compared to controls (41.8 ± 11.4% vs. 30.7 ± 12.2%, p 46.2%). The 1-month mortality differed significantly between the coated-platelet tertiles (p = 0.01) with 46% mortality (6/13) among patients in the lowest tertile (lowest levels) compared to 14.3% (2/14) among those in the middle tertile and 0% in the highest tertile. Conclusions Coated-platelet levels are higher in SAH patients compared to controls. However, lower coated-platelet levels are associated with increased 1-month mortality in SAH patients, a finding compatible with prior observations of an inverse relationship between coated-platelet levels and bleed volume in ICH. The current data support the role played by these prothrombotic platelets in thrombosis or hemorrhage and suggest a potential place for coated-platelet levels in predicting prognosis after SAH.
Tunneling times: a critical review

The old question of "How long does it take to tunnel through a barrier?" has acquired new urgency with the advent of techniques for the fabrication of semiconductor structures in the nanometer range. For the restricted problem of tunneling in a scattering configuration, a coherent picture is now emerging. The dwell time ${\ensuremath{\tau}}_{D}$ has the status of an exact statement of the time spent in a region of space, averaged over all incoming particles. The phase times ${\ensuremath{\tau}}_{T}^{\ensuremath{\phi}}$ and ${\ensuremath{\tau}}_{R}^{\ensuremath{\phi}}$ are defined separately for transmitted and reflected particles. They are asymptotic statements on completed scattering events and include self-interference delays as well as the time spent in the barrier. Consequently, neither the dwell time nor the phase times can answer the question of how much time a transmitted (alternatively, reflected) particle spent in the barrier region. Our discussion of this question relies on a few simple criteria: (1) The average duration of a physical process must be real. (2) Since transmission and reflection are mutually exclusive events, the times ${\ensuremath{\tau}}_{T}$ and ${\ensuremath{\tau}}_{R}$ spent in the barrier region are, if they exist, conditional averages. Consequently, they must obey the identity ${\ensuremath{\tau}}_{D}=T{\ensuremath{\tau}}_{T}+R{\ensuremath{\tau}}_{R}$, where $T$ and $R$ are the transmission and reflection probabilities, respectively. The existence of this identity distinguishes tunneling in a scattering configuration from tunneling out of a metastable state. (3) Any proposed ${\ensuremath{\tau}}_{T}$ and ${\ensuremath{\tau}}_{R}$ must meet every requirement that can be constructed from ${\ensuremath{\tau}}_{D}$. On the basis of (2), the naively extrapolated phase times, as well as the B\"uttiker-Landauer time, must be rejected. The local Larmor times, as introduced by Baz', satisfy (2), but not every criterion of type (3). The local Larmor clock is therefore unreliable. The asymptotic Larmor clock shows the phase times, as it should. Finally, the inverse characteristic frequency of an oscillating barrier cannot always be defined. It is shown not to represent the duration of the tunneling process. This leaves the dwell time and the phase times as the only well-established times in this context. It also leaves open the question of the length of time a transmitted particle spends in the barrier region. It is not clear that a generally valid answer to this question exists.
A Statistical Analysis of Radial Keratotomy in Human Cadaver Eyes

We performed radial keratotomy using the Fyodorov techniques on 14 Eye Bank eyes. Using stepwise regression and best subset statistical analysis, we examined the effects of incision depth, corneal curvature, corneal thickness, corneal diameter, and incision length. We found that the most significant variables affecting postoperative corneal curvature were the incision depth and length. The histologic examination of serial sections of the Eye Bank eyes after this procedure revealed that the average achieved incision depth, using a standard blade depth setting, had variations of up to 30% between eyes. This inability to standardize incision depth may lead to the variable surgical results reported in radial keratotomy.
Association of Lp-PLA2 with digital reactive hyperemia, coronary flow reserve, carotid atherosclerosis and arterial stiffness in coronary artery disease

Abstract Background Lipoprotein-associated Phospholipase A2 (Lp-PLA2), has a powerful inflammatory and atherogenic action in the vascular wall and is an independent marker of poor prognosis in coronary artery disease (CAD). We investigate the association of Lp-PLA2 with markers of vascular dysfunction and atherosclerosis with proven prognostic value in CAD. Methods In 111 patients with angiographically documented chronic CAD, we measured 1) carotid intima-media thickness (CIMT), 2) reactive hyperemia using fingertip peripheral arterial tonometry (RH-PAT), 3) coronary flow reserve (CFR), by Doppler echocardiography 4) pulse wave velocity (PWV) and 5) blood levels of Lp-PLA2. Results Patients with Lp-PLA2 concentration >234.5 ng/ml (50th percentile) had higher CIMT (1.44 ± 0.07 vs. 1.06 ± 0.06 mm), PWV (11.0 ± 2.36 vs. 9.7 ± 2.38 m/s) and lower RH-PAT(1.24 ± 0.25 vs. 1.51 ± 0.53) and CFR (2.39 ± 0.75 vs. 2.9 ± 0.86) compared to those with lower Lp-PLA ( p p = 0.02), PWV (b:0.201, p = 0.04) and inversely with RHI-PAT (b: −0.371, p p = 0.002). In multivariate analysis, Lp-PLA2 was an independent determinant of RHI-PAT, CFR, CIMT and PWV in a model including age, sex, smoking, diabetes, dyslipidemia and hypertension ( p Conclusions Elevated Lp-PLA2 concentration is related with endothelial dysfunction, carotid atherosclerosis, impaired coronary flow reserve and increased arterial stiffness and adverse outcome in CAD patients. These findings suggest that the prognostic role of Lp-PLA2 in chronic CAD may be explained by a generalized detrimental effect of this lipase on endothelial function and arterial wall properties.
Laser-Excited Atomic Fluorescence of Eu, Y, and Tm in a Miniature Glow Discharge Atom Reservoir

A miniature glow discharge (GD) is evaluated as an atom reservoir for laser-excited atomic fluorescence spectrometric measurements of Eu, Y, and Tm. Nanoliter-sized aqueous samples are deposited and dried on the Ni cathode and atomized upon ignition of the GD. The atom population is probed by a copper vapor laser pumped dye laser, and direct-line fluorescence is detected. The optimum chamber pressures and operating currents are 1 Torr and 10 mA for Eu, 2 Torr and 10 mA for Y, and 3 Torr and 40 mA for Tm. The fluorescence temporal profiles are found to consist of short (~20-ms duration) transient spikes, followed by long tails which last more than 60 s as a result of sample redeposition on the cathode surface. The limits of detection (3σ) are 2 fg, 1.2 pg, and 0.08 fg for Eu, Y, and Tm, respectively, with the use of signal area integration over a 6-s duration. Theoretically simulated signals for a particular sample mass, considering the geometry of the GD atomizer, were found to fall within one order of magnitude of those obtained by experiment.
A decoupled load flow method for distribution power networks: algorithms, analysis and convergence study

Abstract In this paper, several solution algorithms for solving distribution power flow equations are investigated. The solution algorithms make use of special characteristics of distribution power networks to achieve computational efficiency. The solution algorithms appear to always converge to load flow solutions when applied to several practical distribution networks. Both analytical results and physical arguments are provided to explain why the solution algorithms always converge. Numerical properties and the robustness issue associated with the solution algorithms are discussed. Properties regarding the convergence and rate of convergence of the solution algorithms are examined. A 69-bus distribution power network is used to demonstrate the efficiency of the solution algorithms.
Femtomolar Zn(II) affinity in a peptide-based ligand designed to model thiolate-rich metalloprotein active sites.

Metal-ligand interactions are critical components of metalloprotein assembly, folding, stability, electrochemistry, and catalytic function. Research over the past 3 decades on the interaction of metals with peptide and protein ligands has progressed from the characterization of amino acid-metal and polypeptide-metal complexes to the design of folded protein scaffolds containing multiple metal cofactors. De novo metalloprotein design has emerged as a valuable tool both for the modular synthesis of these complex metalloproteins and for revealing the fundamental tenets of metalloprotein structure-function relationships. Our research has focused on using the coordination chemistry of de novo designed metalloproteins to probe the interactions of metal cofactors with protein ligands relevant to biological phenomena. Herein, we present a detailed thermodynamic analysis of Fe(ll), Co(II), Zn(ll), and [4Fe-45] 2+ binding to IGA, a 16 amino acid peptide ligand containing four cysteine residues, H 2 N-KLCEGG-CIGCGAC-GGW-CONH 2 . These studies were conducted to delineate the inherent metal-ion preferences of this unfolded tetrathiolate peptide ligand as well as to evaluate the role of the solution pH on metal-peptide complex speciation. The [4Fe-4S] 2+/+ -IGA complex is both an excellent peptide-based synthetic analogue for natural ferredoxins and is flexible enough to accommodate mononuclear metal-ion binding. Incorporation of a single ferrous ion provides the Fe II -IGA complex, a spectroscopic model of a reduced rubredoxin active site that possesses limited stability in aqueous buffers. As expected based on the Irving-Williams series and hard-soft acid-base theory, the Co( II ) and Zn(ll) complexes of IGA are significantly more stable than the Fe(ll) complex. Direct proton competition experiments, coupled with determinations of the conditional dissociation constants over a range of pH values, fully define the thermodynamic stabilities and speciation of each M II -IGA complex. The data demonstrate that Fe II -IGA and Co II -IGA have formation constant values of 5.0 x 10 8 and 4.2 x 10 11 M -1 , which are highly attenuated at physiological pH values. The data also evince that the formation constant for Zn II -IGA is 8.0 x 10 15 M -1 , a value that exceeds the tightest natural protein Zn(ll)-binding affinities. The formation constant demonstrates that the metal-ligand binding energy of a Zn II (S-Cys) 4 site can stabilize a metalloprotein by -21.6 kcal/mol. Rigorous thermodynamic analyses such as those demonstrated here are critical to current research efforts in metalloprotein design, metal-induced protein folding, and metal-ion trafficking.
An optimal incentive scheme for planning with targets

Abstract In socialist economies incentive schemes that contain targets are useful to planners since planners must allocate output to various users. We use a principal-agent model to show that under certain circumstances a first-best Pareto-optimal incentive scheme containing a target exists.
Reliability and Durability of Ceramic Regenerators in a Gas Turbine

The two major causes of failure of ceramic regenerators in a gas turbine engine are excessive thermal stress and chemical attack of the basic ceramic material. Data are presented which show that regenerator life can be correlated on the basis of rim thermal-stress safety factor. Durability gains can be achieved through improved mechanical design of the regenerator system, as well as through improved ceramic materials. The test results from almost 50,000 hr of gas turbine operation on several different candidate materials and design concepts are also presented. Two materials, aluminum silicate and magnesium aluminum silicate, show promise of achieving the durability goals required for automotive and industrial turbine applications.
ELIOT OF HARVARD

Several years ago, I was asked to deliver a mid-summer lecture to a group of university presidents on the subject of leadership. With the unusual luxury of having some time to prepare, I chose not to reflect upon my personal experiences, but to seek inspiration from history. Initially, I planned to draw lessons from the work of the greatest of my Yale predecessors, as well as several presidents with distinguished records at other institutions. The more I read, the more convinced I became that one leader stands above all others in the history of American higher education. He, alas, was not a Yale man.
Parameters affecting the restoration of activity to inactive mutants of thymidylate synthase via subunit exchange: further evidence that thymidylate synthase is a half-of-the-sites activity enzyme.

In a previous study we demonstrated that Escherichia coli thymidylate synthase activity could be restored completely by incubating basically inactive mutants of this enzyme at room temperature with...
Time to first take-back operation predicts successful primary fascial closure in patients undergoing damage control laparotomy

Background Failure to achieve primary fascial closure (PFC) after damage control laparotomy is costly and carries great morbidity. We hypothesized that time from the initial laparotomy to the first take-back operation would be predictive of successful PFC. Methods Trauma patients managed with open abdominal techniques after damage control laparotomy were prospectively followed at 14 Level 1 trauma centers during a 2-year period. Time to the first take-back was evaluated as a predictor of PFC using hierarchical multivariate logistic regression analysis. Results A total of 499 patients underwent damage control laparotomy and were included in this analysis. PFC was achieved in 327 (65.5%) patients. Median time to the first take-back operation was 36 hours (interquartile range 24–48). After we adjusted for patient demographics, resuscitation volumes, and operative characteristics, increasing time to the first take-back was associated with a decreased likelihood of PFC. Specifically, each hour delay in return to the operating room (24 hours after initial laparotomy) was associated with a 1.1% decrease in the odds of PFC (odds ratio 0.989; 95% confidence interval 0.978–0.999; P = .045). In addition, there was a trend towards increased intra-abdominal complications in patients returning after 48 hours (odds ratio 1.80; 95% confidence interval 1.00–3.25; P = .05). Conclusion Data from this prospective, multicenter study demonstrate that delays in returning to the operating room after damage control laparotomy are associated with reductions in PFC. These findings suggest that emphasis should be placed on returning to the operating room within 24 hours after the initial laparotomy if possible (and no later than 48 hours).
Kinetics and mechanistic studies of the atmospheric oxidation of alkynes.

Kinetics studies of the OH-initiated oxidation of 2-butyne, propyne, and acetylene were conducted at 100 Torr and 298 K using turbulent flow chemical ionization mass spectrometry. The major oxidation products were identified, and with the aid of supporting electronic structure thermodynamics calculations, a general OH-initiated oxidation mechanism for the alkynes is proposed. The major product branching ratio and the product-forming rate constants for the 2-butyne-OH adduct + O2 reaction were experimentally determined as well. The atmospheric implications of the chemical oxidation mechanism and kinetics results are discussed.
Induction of tyrosine aminotransferase by dibutyryl cyclic-AMP employing hepatoma cells in tissue culture☆

Abstract Tyrosine aminotransferase (TAT) activity in monolayers of H-35 cells was elevated in response to dibutyryl cyclic-AMP (DBC). Hydrocortisone appeared to potentiate the effect of DBC on TAT. On the basis of cycloheximide studies it appeared that continued protein synthesis was required in order for DBC to elevate TAT enzyme activity. Low levels of actinomycin D (0.2 μg/ml), which inhibited RNA synthesis by 60%, only partially blocked the induction of TAT by DBC. This same level of actinomycin D had no effect on the induction of TAT by insulin. Actinomycin D (5 μg/ml) inhibited RNA synthesis 95% but did not alter the elevation of TAT activity in response to DBC. These results suggest that insulin and DBC act at some post-transcriptional event. It is also suggested that comparative studies with the H-35 cells and HTC cells might provide some insight into the mechanism of cyclic-AMP action in enzyme induction since the H-35 cells respond to DBC and the HTC cells do not.
Berry's phase and the Wess-Zumino effective action in 3HeA

Abstract We show how a Wess-Zumino arises in 3 HeA as a consequence of the nontrivial Berry phase in the ground state.
The physical basis for absorption of light

The effects of light absorption on the wave functions of gas-phase molecules and atoms are investigated by high resolution spectral measurements of radiation emerging from a sample. A Stark-modulated sample of methyl fluoride was irradiated at the 102 GHz rotational transition and the emergent radiation was resolved by means of a spectrum analyzer. For signal oscillator frequencies below or above the molecular resonance by one modulation frequency, the amplitudes of the upper and lower modulation sidebands are found to be of nonuniform intensity, which is inconsistent with amplitude modulation. Emission due to polarization is, however, calculated to be consistent with the results observed, indicating that light absorption should be considered as a subtractive stimulated emission.