cssi/SciSciGPT-SciSciNet huggingface dataset:
A Surgical Robotic System for Treatment of Pelvic Osteolysis Using an FBG-Equipped Continuum Manipulator and Flexible Instruments

This article presents the development and experimental evaluation of a redundant robotic system for the less-invasive treatment of osteolysis (bone degradation) behind the acetabular implant during total hip replacement revision surgery. The system comprises a rigid-link positioning robot and a continuum dexterous manipulator (CDM) equipped with highly flexible debriding tools and a fiber Bragg grating (FBG) based sensor. The robot and the continuum manipulator are controlled concurrently via an optimization-based framework using the tip position estimation (TPE) from the FBG sensor as feedback. Performance of the system is evaluated on a setup that consists of an acetabular cup and saw-bone phantom simulating the bone behind the cup. Experiments consist of performing the surgical procedure on the simulated phantom setup. CDM TPE using FBGs, target location placement, cutting performance, and the concurrent control algorithm capability in achieving the desired tasks are evaluated. Mean and standard deviation of the CDM TPE from the FBG sensor and the robotic system are 0.50 and 0.18 mm, respectively. Using the developed surgical system, accurate positioning and successful cutting of desired straight-line and curvilinear paths on saw-bone phantoms behind the cup with different densities are demonstrated. Compared to the conventional rigid tools, the workspace reach behind the acetabular cup is 2.47 times greater when using the developed robotic system.
Graph-Theoretic Properties of Sub-Graph Entropy

Sub-graph entropy has recently been applied to functional brain network analysis for identifying important brain regions associated with different brain states and for discriminating brain networks of subjects with psychiatric disorders from healthy controls. This letter describes two pertinent properties of sub-graph entropy. It is shown that when a graph is divided into multiple smaller graphs, the summation of their sub-graph entropy is always less than a constant. Additionally, this summation is always greater than the corresponding graph entropy. We also demonstrate that node entropy, a special case of sub-graph entropy, is stable. Experiments using both synthetic data and real world brain network data are carried out to further validate these points. Overall, node entropy has better stability compared to other centrality metrics. Furthermore, our results illustrate that, for human functional brain networks with two different induced states, node entropy has relatively higher change in ranking. Altogether these findings pave the way for real-world applications of sub-graph entropy as a centrality metric in graph signals.
Detection of FGFR fusions in intrahepatic cholangiocarcinoma using targeted RNA sequencing.

e16185Background: Comprehensive sequencing efforts have identified fibroblast growth factor receptor (FGFR) translocations in numerous cancers. FGFR2 fusions were recently identified as an actionab...
Intermittent Tachypnea in the Newborn.

A male infant is born at 38 weeks, 4 days of gestation via spontaneous vaginal delivery to a 20-year-old gravida 4, para 2-0-2-2 woman. The maternal history is significant for substance abuse of cocaine, inadequate prenatal care, iron-deficiency anemia, and newly diagnosed and untreated human immunodeficiency virus (HIV) infection with a viral load of 658 copies/mL. Her medical history includes a repaired congenital ventricular septal defect at the age of 4 years. The infant is vigorous at birth and admitted to the NICU for HIV antiretroviral drug therapy because of the untreated maternal HIV infection. The infant is hemodynamically stable during the first 72 hours after birth and starts having tachypnea on day 3, with respiratory rates ranging from 70 to 90 breaths/min; all his other vital signs are within normal limits. Physical examination findings are unremarkable, with no retractions, no adventitious lung sounds, or cardiac murmurs. The infant requires no respiratory support. Initial chest radiography shows diffuse perihilar interstitial markings and mild ground glass appearance (Fig 1). Because of persistent tachypnea, 2-dimensional (2D) transthoracic echocardiography (Echo) and electrocardiography (EKG) are performed on day 4. EKG shows normal sinus rhythm with rightward axis deviation (normal for age) and no ST/T wave changes. The 2D Echo is significant for the left anterior descending (LAD) coronary artery draining into right ventricle and significantly dilated left main and left anterior coronary arteries (Figs 2, 3, and 4). Follow-up Echo shows worsening of the condition, for which serial cardiac troponins levels are measured. The troponin level is initially normal and then starts to increase as follows: …
Paradoxes & Mysteries in Virus-Infected Supply Chains: Hidden Bottlenecks, Changing Consumer Behaviors, and Other Non-Usual Suspects

In the early onset of the pandemic, COVID-19, in the U.S., consumers experienced surprising shortages of essential, and unrelated at a first look to the pandemic, goods such as toilet paper, yeast and flour, and some of their favorite meat cuts. The “usual” explanations of “demand spikes,” foreign suppliers, trade tariffs, and “hoarding behavior” of panicked consumers, often were failing to explain their persistence. The shortages ended up being real “supply chain struggles,” with their true causes going beyond the “usual” ones, and revealing a set of deeper and “unusual causes.” Our detailed analysis of the affected chains identifies these overlooked failure factors and hidden causes. Such causes include demand shifts among market segments, siloed demand planning, bottlenecks in shared resources of transportation and distribution, and inflexible supply chain structures. We conclude on the lessons from the pandemic crisis on supply chains, and the implied challenges for building resilient supply chains for the future. We need to rethink what is the relevant “system” we plan and optimize (e.g., firm, industry, region, global factor resources, etc.). Building firm-specific redundancy of assets and operational flexibility might be prohibitive in the level of investment required for any one firm, or their financial stakeholders.
Improving Hospital Quality and Costs in Nonoperative Traumatic Brain Injury: The Role of Acute Care Surgeons

Importance The role of acute care surgeons is evolving; however, no guidelines exist for the selective treatment of patients with traumatic brain injury (TBI) exclusively by acute care surgeons. We implemented the Brain Injury Guidelines (BIG) for managing TBI at our institution on March 1, 2012. Objective To compare the outcomes in patients with TBI before and after implementation of the BIG protocol. Design, Setting, and Participants We conducted a 2-year analysis of our prospectively maintained database of all patients with TBI (findings of skull fracture and/or intracranial hemorrhage on an initial computed tomographic scan of the head) who presented to our level I trauma center. The pre-BIG group included patients with TBI from March 1, 2011, through February 29, 2012, and the post-BIG group included patients from July 1, 2012, through June 30, 2013. Main Outcomes and Measures The primary outcome measures were patients with repeated computed tomography of the head and neurosurgical consultations. Secondary outcome measures were findings of progression of intracranial hemorrhage on repeated computed tomographic scans, neurosurgical intervention, hospital admission, intensive care unit admission, hospital and intensive care unit length of stay, 30-day readmission rate, and hospital costs per patient. Results A total of 796 patients (415 in the pre-BIG group and 381 in the post-BIG group) were included. There was a significant reduction (19.0%) in the rate of neurosurgical consultation (post-BIG group, 273 patients [71.7%]; pre-BIG group, 376 [90.6%]; P P P P = .01), hospital length of stay (post-BIG group, 5.4 [4.5] days; pre-BIG group, 6.1 [4.8] days; P = .03), and hospital costs per patient ($4772 per patient; P = .03) with implementation of BIG. There was no difference in the in-hospital mortality rate (post-BIG group, 62 patients [16.3%]; pre-BIG group, 69 patients [16.6%]; P = .89), progression of intracranial hemorrhage on repeated scans (post-BIG group, 41 patients [10.8%]; pre-BIG group, 59 patients [14.2%]; P = .14), neurosurgical intervention (post-BIG group, 61 patients [16.0%]; pre-BIG group, 59 patients [14.2%]; P = .48), and 30-day readmission rate (post-BIG group, 31 patients [8.1%]; pre-BIG group, 37 patients [8.9%]; P = .69) after implementation of BIG. Conclusions and Relevance Implementation of BIG is safe and cost-effective. BIG defines the management of TBI without the need for neurosurgical consultation and unnecessary imaging. Establishing a national, multi-institutional study implementing the BIG protocol is warranted.
The Psychological Impacts of Cyberlife Engagement

This essay synthesizes scientific research across two decades on the influence of cyberlife engagement on cognitive processes, mental and physical health, and interpersonal interactions, highlighting the increasingly pervasive presence of digital innovation in society. New possibilities afforded by the integration of technology in commerce, relationships, therapy, and education are discussed, as are prevalent topics of interest within cyberpsychological research. We present an analysis of the positivity with which information and communication technology is portrayed in scientific literature since its emergence in society and discuss important future directions of study as technology's presence and influence continue to grow on an exponential scale. Last, we present current voids in cyberpsychological research, focusing particularly on the question of digital culture, or the impact of cyberlife engagement on global cultures as both geographical and custom-based barriers are traversed with increasing ease. Keywords: cyberpsychology; cyberlife engagement; information technology; digital culture; Internet; media; computers; health
Bushman Letters: Interpreting |Xam Narratives

Reviewed Medium: book Authors: Michael Wessels Year: 2010 Pages: 256 Publisher: Wits University Press ISBN: 978-1868145065 (soft cover).
Integrating Variables and Operations into Rule-Based Forward Chaining Systems

The features of a rule-based programming language called PICASSO are surveyed that provides modular structures for rule-based programming and allows to interface sets of rules by operations. Furthermore, the proposed language provides encapsulation by generalizing the notation of variables in three ways. First, it extends the scope of variables to modules, which can be considered as sets of rule sets cooperating in a given, fixed context. Second, we introduce the concept of multi-instantiated variables, which facilitates the exchange of results and inputs between rule-based programs as well as the formulation of repetitive loops. Third, relationships between variables can be defined, which facilitates the formulation of tasks for related objects, e.g., married couples.
Getting the Message In: A Global Company's Experience with the New Generation of Low-Cost, High Performance Machine Translation Systems

Most large companies are very good at "getting the message out" - publishing reams of announcements and documentation to their employees and customers. More challenging by far is "getting the message in" - ensuring that these messages are read, understood, and acted upon by the recipients. This paper describes NCR Corporation's experience with the selection and implementation of a machine translation (MT) system in the Global Learning division of Human Resources. The author summarizes NCR's vision for the use of MT, the competitive "fly-off" evaluation process he conducted in the spring of 2000, the current MT production environment, and the reactions of the MT users. Although the vision is not yet fulfilled, progress is being made. The author describes NCR's plans to extend its current MT architecture to provide real-time translation of web pages and other intranet resources.
The Oldest, Toughest Cells in the Heart

We review here the evolution and development of the earliest components of the cardiac pacemaking and conduction system (PCS) and the turnover or persistence of such cells into old age in the adult vertebrate heart. Heart rate is paced by upstream foci of cardiac muscle near the future sinoatrial junction even before contraction begins. As the tubular heart loops, directional blood flow is maintained through coordinated sphincter function in the forming atrioventricular (AV) canal and outflow segments. Propagation of initially peristaltoid contraction along and between these segments appears to be influenced by physical conditioning and orientation of inner muscle layers as well as by their slow relaxation; all characteristic of definitive conduction tissue. As classical elements of the mature conduction system emerge, such inner 'contour fibres' maintain muscular and electrical continuity between atrial and ventricular compartments. Elements of such primordial architecture are visible also in histological and optical electrical study of fish and frog hearts. In the maturing chick heart, cells within core conducting tissues retain early thymidine labels from the tubular heart stage into adult life, dividing only slowly, if at all. Preliminary evidence from mammals suggest similar function and kinetics for these 'oldest, toughest' cells in the hearts of all vertebrates.
Renal Failure During the First Year of Life

All cases of persistent renal failure in infants less than 1 year of age were reviewed to determine whether the prognosis has improved equally for infants as for adults. During a ten-year period, 52 infants were treated by applying uniform therapy; 28, more than half, were less than 4 weeks old. All cases were separated into two groups; 19 infants without and 33 infants with congenital renal or urinary tract anomalies. In 20 patients of the latter group, additional serious anomalies of other organs were present. The age distribution was strikingly different: in 18 of 21 infants, renal anomalies were present, as diagnosed on the first day of life. In contrast, only 3 of 11 infants, 4 to 12 months old, had urinary tract anomalies. In infants without renal anomalies, renal failure was caused by hypotension or shock in 10 of 19 cases, by pyelonephritis or sepsis un 6 of 19. Of this group, eight infants (42%) recovered completely, nine (47%) died. Death occurred within one to two days of hospitalization in all but three cases, caused by shock or sepsis. In this group medical problems that are amenable to therapy have caused either renal failure or contributed to the infant's death. In infants with renal or urinary tract anomalies, renal failure was caused by renal dysplasia or agenesis in 16 of 33 infants, by urinary tract obstruction in 12 of 33. Only three patients (9%) recovered, all older than 4 months, 20 (61%) died, and 10 are living with signs of chronic renal failure. Death usually occurred within one week of hospitalization and, in 16 of 20, it was caused by renal failure and multiple additional anomalies. The multiplicity and complexity of the congenital anomalies in most instances precluded effective, lifesaving therapy. Renal failure in infants is still a serious disease accompained by a high mortality rate in which therapeutic possibilities are limited. No improvement in prognosis can be expected in the near future. Pediatrics, 59:987-994, 1977, RENAL FAILURE, CONGENITAL RENAL ANOMALIES, INFANT, ISCHEMIC RENAL DAMAGE.
Metal-metal interactions of aqueous lead(II) and tin(II) ions with the ground and excited states of tetrakis(μ-diphosphito)diplatinate(II)

Abstract The interactions of the metal-metal bonded compound tetrakis(μ-diphosphito)diplatinate(II), Pt 2 (P 2 0 5 H 2 ) 4 4− , in its ground state (Pt 2 ; λ abs =368 nm) and lowest energy triplet excited state ( * Pt 2 ; λ lum =514 nm) with the metal ions Pb 2+ and Sn 2+ in aqueous solution are investigated by electronic absorption and photoluminescence spectroscopies. New bands in the visible region of the absorption spectrum are assigned to charge transfer transitions from Pt 2 to Pb 2+ and Sn 2+ . These transitions are proposed to result from ground state metal-metal interactions of Pb 2+ and Sn 2+ with Pt at the axial sites of Pt 2 , interactions which also appear to be responsible for the observed static quenching of * Pt 2 by these ions. In the case of Pb 2+ in aqueous acid solutions ionic strength-dependent diffusional quenching of * Pt 2 occurs ( k ≈ 10 9 −10 10 l mol −1 s −1 ), and no evidence for ground state interactions was found. The quenching process is proposed to be due to an excited state electron transfer reaction from * Pt 2 to Pb 2+ yielding Pt 2 + and Pb + . These results are consistent with recent estimates of the reduction potentials of the Pt 2 + / * Pt 2 and Pb 2+ /Pb + redox couples and enable an estimate of E o >−1.6 V versus NHE for the aqueous Sn 2+ /Sn + couple to be made. The sharply contrasting behavior between the isoelectronic Pb 2+ and Tl + ions towards Pt 2 and * Pt 2 is discussed in the context of these results.
Electroporation-mediated transient gene expression in intact cells of sweetpotato

Transient expression of the β-glucuronidase (GUS) gene has been studied in leaf-derived embryogenic callus of sweetpotatoIpomoea batatas L. (Lam.) by electroporation. The influence of several factors including electric field strength, buffer composition, time course of transientGUS gene expression, DNA concentration, enzyme, and polyethylene glycol (PEG) treatment was examined onGUS gene expression (number of blue spots). MaximumGUS gene expression (an average of 90 blue spots/fifty mg fresh weight callus tissue) was observed after 48 h when callus pieces were preincubated with electroporation (EPR) buffer for 1 h, followed by electroporation with a single electric pulse of 500 V/cm discharged from a 960-μF capacitor in the presence of 20 μg DNA/ml and 8.3 μl NaCl (3M). Changing the electroporation buffer conductivity (by varying the buffer composition with low-high salt concentrations), had only slight effect on the number of blue spots. Similarly, the time course study ofGUS gene expression revealed that GUS activity could be detected 12 h after electroporation with a maximum activity after 72 h (112 blue spots). Increasing the amount of DNA from 5 to 50 μg/ml in the EPR buffer had a slight effect on the expression frequency (from 20–110 blue spots, and 112 blue spots with 20 μg/ml). The number of blue spots was increased by enzymatic wounding of callus pieces for 10 min and by addition of 200 μl PEG 4000 (15%) before electroporation. These results suggest that intact cell electroporation can be used for producing transgenic sweetpotato tissue.
Disruption of epidermal specific gene expression and delayed skin development in AP-2γ mutant mice

The development of the epidermis, a stratified squamous epithelium, is dependent on the regulated differentiation of keratinocytes. Differentiation begins with the initiation of stratification, a process tightly controlled through proper gene expression. AP-2γ is expressed in skin and previous research suggested a pathway where p63 gene induction results in increased expression of AP-2γ which in turn is responsible for induction of K14. This study uses a conditional gene ablation model to further explore the role of AP-2γ in skin development. Mice deficient for AP-2γ exhibited delayed expression of p63, K14, and K1, key genes required for development and differentiation of the epidermis. In addition, microarray analysis of E16.5 skin revealed delayed expression of additional late epidermal differentiation genes: filaggrin, repetin and secreted Ly6/Plaur domain containing 1, in mutant mice. The genetic delay in skin development was further confirmed by a functional delay in the formation of an epidermal barrier. These results document an important role for AP-2γ in skin development, and reveal the existence of regulatory factors that can compensate for AP-2γ in its absence.
Late Removal of Titanium Hardware from the Elbow Is Problematic

A retrospective review of 21 patients that underwent bone screw removal from the elbow was studied in relation to the type of metal, duration of implantation, and the location of the screws about the elbow. Screw failure during extraction was the dependent variable. Five of 21 patients experienced hardware failure during extraction. Fourteen patients had titanium alloy implants. In four cases, titanium screws broke during extraction. Compared to stainless steel, titanium screw failure during removal was not statistically significant (𝑃=0.61). Screw removal 12 months after surgery was more likely to result in broken, retained screws in general (𝑃=0.046) and specifically for titanium alloy (𝑃=0.003). Bone screws removed from the distal humerus or proximal ulna had an equal chance of fracturing (𝑃=0.28). There appears to be a time-related association of titanium alloy bone screw failure during hardware removal cases from the elbow. This may be explained by titanium’s properties and osseointegration.
The evolution of gender identity.

1. Core gender identity is established by the age of three. 2. Other maturational levels of development follow until post-adolescent, mature gender identity is attained. 3. Disturbance in the earliest periods of development result in ambiguous gender identities that compose the group of transsexuals, transvestites, and homosexuals. 4. Mature gender identity infers a capacity for a heterosexual relationship with care and tenderness. 5. Gender identity is one aspect of personal identity. 6. The most urgent and constant need of the individual is to maintain a sense of identity in order to deal with reality effectively.
A two-dimensional polyacrylamide gel electrophoresis (PAGE) system using sodium dodecyl sulfate-PAGE in the first dimension.

Abstract A two-dimensional gel electrophoretic system for the separation of cellular proteins is described. The system utilizes sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis in the first dimension and polyacrylamide gel isoelectric focusing in the second dimension. The system offers a good starting point for many difficult protein separations requiring SDS.
Solubility and degradation of polyhydroxyalkanoate biopolymers in propylene carbonate

New biobased materials and chemicals require different processing strategies than petroleum-derived commodities. The extraction and recovery of polyhydroxyalkanoate (PHA) biopolymers from the residual cellular biomass is particularly difficult because the polymer is accumulated within the cell. PHAs have low solubility in many classical polymer solvents and are most often dissolved using undesirable chlorinated solvents. The solubility kinetics is greatly diminished when these polymers are highly crystalline. Here, 1,2-propylene carbonate is used to dissolve highly crystalline polyhydroxybutyrate at ambient pressures and moderate temperatures. We have used kinetic studies of the dissolution of the crystalline material to determine the energy barrier for dissolution of the system. Further, the degradation of polyhydroxybutyrate and similarly prepared PHA block copolymers were studied during this extraction process using molecular weight characterization by gel permeation chromatography. Finally, we have used these findings to extract PHA block copolymers from dried biomass at the bench scale. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Moral judgement in adolescents: Age differences in applying and justifying three principles of harm

This study investigated the application and justification of three principles of harm in a cross-sectional sample of adolescents in order to test recent theories concerning the source of intuitive moral judgements. Participants were 46 early (M age = 14.8 years) and 40 late adolescents (M age = 17.8 years). Participants rated the permissibility of various ethical dilemmas, and provided justifications for their judgements. Results indicated participants aligned their judgements with the three principles of harm, but had difficulty explaining their reasoning. Furthermore, although age groups were consistent in the application of the principles of harm, age differences emerged in their justifications. These differences were partly explained by differences in language ability. Additionally, participants who used emotional language in their justifications demonstrated a characteristically deontological pattern of moral judgement on certain dilemmas. We conclude adolescents in this age range apply the principle...
Experimental demonstration of ultraviolet pulse broadening in short-range non-line-of-sight communication channels

An experimental test-bed using a narrow-pulsed ultraviolet (UV) laser and high-bandwidth photomultiplier tube was set up to characterize pulse broadening effects in short-range non-line-of-sight (NLOS) scattering communication channels. Pulse broadening is reported as a function of the transmitter elevation angle, transmitter beam angle, receiver elevation angle, receiver field-of-view, and transmitter-receiver distance. The results provide insight into the channel bandwidth and achievable communication data rate.
The transcription factor DREAM represses the deubiquitinase A20 and mediates inflammation

Here we found that the transcription repressor DREAM bound to the promoter of the gene encoding A20 to repress expression of this deubiquitinase that suppresses inflammatory NF-κB signaling. DREAM-deficient mice displayed persistent and unchecked A20 expression in response to endotoxin. DREAM functioned by transcriptionally repressing A20 through binding to downstream regulatory elements (DREs). In contrast, binding of the transcription factor USF1 to the DRE-associated E-box domain in the gene encoding A20 activated its expression in response to inflammatory stimuli. Our studies define the critical opposing functions of DREAM and USF1 in inhibiting and inducing A20 expression, respectively, and thereby the strength of NF-κB signaling. Targeting of DREAM to induce USF1-mediated A20 expression is therefore a potential anti-inflammatory strategy for the treatment of diseases associated with unconstrained NF-κB activity, such as acute lung injury.
Digital computer method for quantitation of gas-liquid chromatography as applied to fatty acid esters☆

Abstract A digital computer program is described that accepts, as input, peak heights and retention time measurements, and provides, as output, tables of sample composition (both in weight and percentage terms) and information on component identification. Computations are based upon results from GLC records obtained with standard mixtures. A 5-parameter exponential function is used to correct for systematic nonlinearities of GLC. Corrections are introduced for incomplete resolution of peaks. A nonlinear function is used to correct carbon number (equivalent chain length) data for the systematic errors related to fact that each component delays the appearance of all later components. The result of these corrections is an increase in analytical accuracy by a factor of up to 10-fold.
A high-temperature chemical kinetic model for primary reference fuels

A chemical kinetic mechanism has been developed to describe the high-temperature oxidation and pyrolysis of n-heptane, iso-octane, and their mixtures. An approach previously developed by this laboratory was used here to partially reduce the mechanism while maintaining a desired level of detailed reaction information. The relevant mechanism involves 107 species undergoing 723 reactions and has been validated against an extensive set of experimental data gathered from the literature that includes shock tube ignition delay measurements, premixed laminar-burning velocities, variable pressure flow reactor, and jet-stirred reactor species profiles. The modeled experiments treat dynamic systems with pressures up to 15 atm, temperatures above 950 K, and equivalence ratios less than approximately 2.5. Given the stringent and comprehensive set of experimental conditions against which the model is tested, remarkably good agreement is obtained between experimental and model results. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 399–414, 2007
Extension of Newton's method to nonlinear functions with values in a cone

We show how Newton's method may be extended, using convex optimization techniques, to solve problems of the form $$Find \bar x such that f(\bar x) \in K$$ , whereK is a nonempty closed convex cone in a Banach spaceY, andf is a function from a reflexive Banach spaceX intoY. A generalization of the Kantorovich theorem is proved, giving convergence results and error bounds for this method.
Procedures for Obtaining and Analyzing Writing Samples of School-Age Children and Adolescents.

Purpose Many students' writing skills are below grade-level expectations, and students with oral language difficulties are at particular risk for writing difficulties. Speech-language pathologists'...
Consequences of Correlated Solvation on the Structures and Reactivities of RLi-Diamine Complexes: 1,2-Addition and α-Lithiation Reactions of Imines by TMEDA-Solvated n-Butyllithium and Phenyllithium

6Li and 13C NMR spectroscopic studies were carried out on [6Li]n-BuLi and [6Li]PhLi (RLi) in toluene-d8 containing the following diamines: N,N,N‘,N‘-tetramethylethylenediamine (TMEDA), N,N,N‘,N‘-tetraethylethylenediamine, 1,2-dipyrrolidinoethane, 1,2-dipiperidinoethane, N,N,N‘,N‘-tetramethylpropanediamine, trans-(R,R)-N,N,N‘,N‘-tetramethylcyclohexanediamine, and (−)-sparteine. Dimers of general structure (RLi)2S2 (S = chelating diamine) are formed in each case. Treatment of RLi with two different diamines (S and S‘) affords homosolvates (RLi)2S2 and (RLi)2S‘2 along with a heterosolvate (RLi)2SS‘. Relative binding constants and associated free energies for the sequential solvent substitutions are obtained by competing pairs of diamines. The high relative stabilities of certain heterosolvates indicate that solvent binding to the RLi dimer can be highly correlated. Rate studies of both the 1,2-addition of RLi/TMEDA to the N-isopropylimine of cyclohexane carboxaldehyde and the RLi/TMEDA-mediated α-lithiation...
A nuclear protein with affinity for the 5′ flanking region of a cell cycle dependent human H4 histone gene in vitro

A nuclear protein with affinity for the 5' flanking region of a cell cycle dependent human H4 histone gene has been partially purified from nuclear extracts of human HeLa S3 cells. The region involved in the binding of the protein has been localized to an upstream DNA segment using an electrophoretic mobility shift assay. This DNA segment is devoid of RNA polymerase II consensus sequences and contains both homopurinic and A/T rich tracts. Analogous experiments have identified a similar, and perhaps identical, factor that has affinity for a cell cycle dependent human H3 histone gene promoter. This protein appears to bind to a DNA segment containing A/T rich sequences that bear homology with the binding region of the H4 histone promoter. Cell synchronization experiments have shown that the overall affinity of the protein(s) for the H3 and H4 histone 5' flanking regions in vitro is not dramatically altered during the cell cycle. Although the rate of histone gene transcription is modulated during early S phase, transcription occurs throughout the cell cycle. Hence, the protein(s) we have detected here may play a role in the basal expression of these genes.
Quantification of focal dystonia in pianists using scale analysis

Focal dystonia in pianists is a task-specific movement disorder that causes loss of pianistic skills and provokes irregularities in playing. So far, no method has been available for objective quantification of the disorder. Eight professional pianists with focal dystonia and eight healthy professional pianists matched by age, gender, and handedness were examined, using a newly developed MIDI-based Scale Analysis as well as the Arm Dystonia Disability Scale (ADDS). Key velocities and timing parameters were analyzed. In 5 pianists with dystonia, follow-up examinations were carried out after treatment with botulinum toxin-A. In affected hands, significantly higher mean standard deviations of timing parameters were seen compared with healthy reference hands. After treatment with botulinum toxin-A, significant improvements in performance parameters were monitored by Scale Analysis. Mean standard deviations of inter-onset intervals correlated with ADDS scores. We conclude that Scale Analysis is an effective and precise tool for quantification of focal dystonia in pianists and provides fine resolution. It is independent of rating methods and allows reliable follow-up examinations during treatment.
A stochastic model of the HIV epidemic and the HIV infection distribution in a homosexual population

In this paper we develop a stochastic model for the HIV epidemic in a homosexual population and use the model to characterize the HIV infection distribution and seroconversion distribution. Through computer-generated infection distributions and seroconversion distributions, we assess the effects of various risk factors on these distributions. The fitting of some data sets generated by computer suggests that the three-parameter generalized log-logistic distribution should be assumed as the infection distribution for the proposed stochastic model of HIV epidemics.
The Postcolonial Caribbean as a Liminal Space: Authoring Other Modes of Contestation and Affirmation

This introductory article, by way of explicating the rationale behind the focus of this special issue, discusses some of the debate concerning the theoretic utility of tropes such as liminality and hybridity for analyzing the negotiation of identity and cultural production in the English-speaking Caribbean. The article critiques the spatial and temporal metaphors that underlie these tropes, drawing on the work of postcolonial scholars who have sought to contextualize postcolonial theory within communication studies. The article ends by proposing that performance may offer alternative perspectives for theorizing resistance to hegemony as communicatively constructed.
Portal hypertension and its complications.

Purpose of review Portal hypertension is responsible for most of the complications associated with cirrhosis, specifically variceal hemorrhage, ascites and hepatic encephalopathy. Progress in understanding the pathophysiology of portal hypertension and improvements in the diagnosis and management of its complications that have occurred over the last year are discussed. Recent findings Endothelial dysfunction contributes to the pathogenesis of portal hypertension and may represent a novel therapeutic target. Hepatic venous pressure gradient measurements, when properly performed, are useful in the management of patients with cirrhosis. Hyponatremia in cirrhosis has prognostic value and novel aquaretic and other agents may provide alternative approaches to the management of chronic liver disease. The mechanisms for bacterial translocation in cirrhosis that predisposes patients to infectious complications, such as spontaneous bacterial peritionitis, are being explored. Adrenal insufficiency is common in septic patients with advanced cirrhosis and corticosteroids may provide a survival benefit. Pulmonary disease complicates the management of patients with advanced liver disease. Summary Significant advances continue to be made in the diagnosis and management of the complications of portal hypertension in the face of an increasing burden of chronic liver disease.
Adaptive control of machine tools: the past and projected role of numerical control computers

Abstract Unattended operation has placed special demands on controls for machine tools. This paper reviews the research of the past 25 years and summarizes a variety of systems for adaptive control (AC) of machine tools. Special attention is given to the computer used and its role in the system. These systems have not been widely applied because of the high cost of the hardware in comparison to anticipated benefits. With present day computer numerical control (CNC) systems, AC is more easily implemented with lower cost software changes. Further, the increasing importance of unattended operation has greatly increased the expected benefits. Research has shown the need for the development of parameters adaptive systems which are stable and can provide on-line estimates of process parameters. Such control must insure that operations are within the constraints imposed by the machine. Equally important, the control must embody the sensing and measurement required for efficient tool management. That is, the system should measure tool wear and provide for automatic tool replacement. The authors present a state space model and associated methodology to address these issues for a CNC lathe.
Serum Inhibitors of Fibrinolysis

Four protease inhibitors have been identified in human serum and methods for their isolation are described. After removal of the euglobulin fraction, serum was submitted to ion exchange chromatography and gel filtration, and fractions were tested for inhibition of the lysis of plasminogen-deficient fibrin clots by plasmin, trypsin and elastase. In addition inhibitors of plasminogen activation were sought by studying the effects of separated fractions on the lysis of plasminogen-rich fibrin clots by urokinase. Examination by immunophoresis showed that three of the separated inhibitors were alpha2-macroglobulin, alpha1-antitrypsin and inter-alpha-trypsin inhibitor. The fourth antiprotease was a powerful inhibitor of both urokinase-induced and plasmin-induced clot lysis, and was identified as an inter-alpha-globulin from its electrophoretic mobility in agarose gels.
Structural Mechanism of GAF-Regulated σ54 Activators from Aquifex aeolicus

Abstract The σ subunits of bacterial RNA polymerase occur in many variant forms and confer promoter specificity to the holopolymerase. Members of the σ54 family of σ subunits require the action of a ‘transcriptional activator’ protein to open the promoter and initiate transcription. The activator proteins undergo regulated assembly from inactive dimers to hexamers that are active ATPases. These contact σ54 directly and, through ATP hydrolysis, drive a conformational change that enables promoter opening. σ54 activators use several different kinds of regulatory domains to respond to a wide variety of intracellular signals. One common regulatory module, the GAF domain, is used by σ54 activators to sense small-molecule ligands. The structural basis for GAF domain regulation in σ54 activators has not previously been reported. Here, we present crystal structures of GAF regulatory domains for Aquifex aeolicus σ54 activators NifA-like homolog (Nlh)2 and Nlh1 in three functional states—an ‘open’, ATPase-inactive state; a ‘closed’, ATPase-inactive state; and a ‘closed’, ligand-bound, ATPase-active state. We also present small-angle X-ray scattering data for Nlh2-linked GAF-ATPase domains in the inactive state. These GAF domain dimers regulate σ54 activator proteins by holding the ATPase domains in an inactive dimer conformation. Ligand binding of Nlh1 dramatically remodels the GAF domain dimer interface, disrupting the contacts with the ATPase domains. This mechanism has strong parallels to the response to phosphorylation in some two-component regulated σ54 activators. We describe a structural mechanism of GAF-mediated enzyme regulation that appears to be conserved among humans, plants, and bacteria.
Functional comparison of the inductions of NADPH oxidase activity and Fcγ RI in IFNγ-treated U937 cells☆

Abstract The capacity to generate Superoxide anion (O − 2 ) can be induced in U937 cells by various agents known to cause myeloid cell differentiation. Other reported differentiation events include diminished cell proliferation and the induction by gamma-interferon (IFNγ) of Fc receptors for immunoglobulin G1 (FcγRI). In this study, we differentiated U937 cells and high FeγRI-expression mutants of U937 cells by treating them with IFNγ. We compared the time courses over which surface FcγRI became maximal, NADPH oxidase activity was induced, and the antiproliferative effect of IFNγ was detected. Oxidase activity was measured by stimulating cells with PMA or by activating surface FcγRI using aggregated human IgG1 or second antibody crosslinking of mAb 32/Fcγ RI complexes. We found that IFNγ in the absence of additional lymphokines induced high levels of oxidase activity in maximally differentiated U937 cells with even higher levels in the fully differentiated high-Feγ RI expression mutants (>8 nmoles/10 6 cells/min for A12.13 cells). Over the course of differentiation, maximal induced levels of Fcγ RI were reached after 1 to 2 days of IFNγ treatment, prior to the antiproliferative effect of the lymphokine. In contrast, oxidase activity was induced after a lag of approximately 2 days, becoming maximal only after 4 to 6 days of IFNγ treatment. This comparison of the induction of FcγRI with that of oxidase activity triggered through Fcγ RI indicated that the rapid increase of surface receptor was not accompanied by a completion of the pathway of Feγ RI-mediated oxidase activity. However, the time courses of induction detected by PMA and Feγ RI-agonists were coincident suggesting that the development of oxidative capacity could be due to the induction of components required by both the PMA- and surface receptor-mediated pathways. There are several oxidase components that are known to be IFNγ-inducible, such as the oxidase flavoprotein, a b558 cytochrome peptide, and oxidase-requiring cytosolic components, and it is possible that one or a set of these components could be the limiting factor(s) for IFNγ-induced oxidase activity.
The Effect of Time Constraints and Statistics Test Anxiety on Test Performance in a Statistics Course

Abstract The performance of students who completed a statistics examination under time limits was compared with that of students under no time limits. Another purpose of the study was to determine whether students high or low in statistics test anxiety were affected differentially by these two examination conditions. Twenty-six graduate students who were enrolled in an intermediate-level statistics course were randomly assigned to the two examination groups, timed or untimed. Both low- and high-anxious students performed better on the final course examination under the untimed condition than under the timed condition. However, the benefit of the untimed examination was greater for high-anxious students than for low-anxious students. The results were interpreted using Hill's (1984) and Wine's (1980) conceptual frameworks. The results suggest that differences between high- and low-anxious students in evaluative situations are caused by differences between them in motivational disposition and attentional focus.
Creating virtual user populations by analysis of anthropometric data

Abstract Anthropometric measures that accurately represent the target user population are essential to effective designing for human variability, yet the available anthropometric data are drawn from populations that are substantially dissimilar from the target populations for most products and environments. Many designs for civilians are assessed using military anthropometric data, for example, because the only available data with sufficient detail were gathered from soldiers. Recent studies have collected detailed information from civilians, but these populations are also not representative of typical user populations. This paper presents a new statistical method for applying the available anthropometric data to estimate distributions of anthropometric data for a target population. For many design problems, the target population can be characterized by overall demographic information, such as the gender ratio, age distribution, nationality, and ethnicity. Principal component analysis and linear regression are used to create statistical models that can draw on information from two or more databases to estimate values for a large range of anthropometric variables. The approach matches the race/ethnicity distribution of the target user population and incorporates a stochastic component so that all relevant variance is retained. Finally, it generates populations of virtual users rather than summary statistics for individual variables. Summary statistics from the virtual populations are shown to be reasonable approximations for the actual measures. This work has application to a wide range of design problems, including the design of workspaces, vehicles, and medical devices. Relevance to industry: Accurate estimates of target user anthropometry are essential to spatial analyses in artifact and task design. This paper presents a methodology for using available data to synthesize new populations that better represent target users. Application of these methods in the design and assessment of products and environments will produce more accommodating designs that promote better performance and customer acceptance.
Oxygen isotope ratios in Holocene carbonates across a climatic gradient, eastern Washington State, USA: Evidence for seasonal effects on pedogenic mineral isotopic composition

Oxygen isotope ratios of pedogenic carbonates were analyzed along a climatic gradient in the Palouse region of eastern Washington State to evaluate changes in their isotopic composition with changing climate. A modern analog approach was used to assess the relationship between the istotope ratios in the pedogenic carbonates with those in soil water (measured in June when we anticipated carbonate formation might occur because of low soil water content), and meteoric water from two National Atmospheric Deposition Program (NADP) sites adjacent to our sequence. Mean annual meteoric water δ18O values (wrt VSMOW) from the two NADP sites varied slightly with elevation, —13.9‰ at the Starkey site (elevation 1253 m) and —13.0‰ at the Palouse site, (elevation 766 m) but showed distinct seasonal trends with weighted means ranging from —11.9‰ during autumn to —15.0‰ during the winter. Carbonate δ18O (wrt VPDB) varied significantly with MAP, ranging from —14.1‰ at the most arid site to —11.4‰ at the wettest site but d...
Regional and subcellular distribution of cholinergic enzyme and receptor activity in goldfish brain.

The subcellular and regional distribution of markers for cholinergic activity was studied in goldfish brain. Nicotinic-cholinergic receptor ‘activity’ was analysed by the binding of [125I]alphabungarotoxin (Kd = 0.5 nm) and muscarinic cholinergic ‘activity’ by binding of [3H]quinuclidinyl benzilidate (Kd= 0.4 nm). Choline acetyltransferase and acetylcholinesterase activities were also estimated. The subcellular distribution demonstrated an enrichment of the recovered activity in the synaptosomal fractions. In general, the pharmacological studies of receptor binding demonstrated an appropriate specificity for cholinergic receptors. The regional distribution of the markers was compared to data obtained from other species: while choline acetyltransferase in mammals is present in highest specific activity in the telecephalon, in the goldfish the activity is much greater in the hindbrain. Likewise, the binding of quinuclidinyl benzilidate by the diencephalon of the goldfish brain was greater than that by the tetencephalon; but the marked enrichment of choline acetyltransferase in the hindbrain was not accompanied by an enrichment in the material that bound quinuclidinyl benzilidate.