cssi/SciSciGPT-SciSciNet huggingface dataset:
Daytime Light Intensity Modulates Spatial Learning and Hippocampal Plasticity in Female Nile Grass Rats (Arvicanthis niloticus)

Abstract Light has pervasive effects on the physiology and behavior of mammals. Several human studies have shown that light modulates cognitive functions; however, the mechanisms responsible for the effects of light remain unclear. Our previous work using diurnal male Nile grass rats (Arvicanthis niloticus) revealed that reduced illuminance during the day leads to impairments in hippocampal-dependent spatial learning/memory, reduced CA1 dendritic spine density, and attenuated hippocampal brain-derived neurotrophic factor (BDNF) expression in males. The present study examined the impact of ambient light intensity on hippocampal functions in female grass rats and explored sex differences in behavioral and hippocampal responses. Female grass rats were housed in either a 12:12-hr bright light–dark (brLD, 1000 lx) or dim light–dark (dimLD, 50 lx) cycle for four weeks. The dimLD group showed impaired spatial memory in the Morris water maze task and reduced CA1 apical dendritic spine density, similar to prior observations in males. However, the behavioral deficits seen in females were more severe than those seen in males, with dimLD females showing no evidence of long-term retention over the 24-hour periods between training sessions. In contrast to the attenuated hippocampal BDNF expression found in dimLD males, there was no significant difference in the expression of BDNF and of its receptor TrkB between females in brLD and dimLD. The results suggest that, as seen in male grass rats, reduced illuminance during the day impairs hippocampal-dependent spatial memory and hippocampal plasticity in female diurnal grass rats, but the underlying signaling pathways responsible for the effects of light restriction may differ between the sexes.
Magnetic resonance imaging response in patients treated with definitive radiation therapy for medically inoperable endometrial cancer-Does it predict treatment response?

Abstract Purpose Many patients with endometrial cancer cannot undergo surgery and instead receive definitive radiation therapy (RT). We investigate the correlation between MRI response to RT and clinical outcomes. Methods and Materials Women with inoperable, clinical Stage I endometrial cancer were treated with definitive brachytherapy (BT) with/without pelvic RT (PRT). Patients underwent MRI with functional diffusion-weighted imaging before and after RT. A radiologist retrospectively classified cases as complete, partial, or indeterminate response (CR, PR, or IR, respectively) vs. disease progression. Local control was clinicopathologically defined. Results From 2007 to 2017, 50 women underwent definitive RT. Thirty-five (70%) received BT alone (median dose 37.5 Gy). For combined therapy, the median PRT and BT doses were 45 and 25 Gy, respectively. Median gross tumor volume and high-risk clinical target volume were 7.1 cc and 90.0 cc, respectively. Median followup among living patients was 20 months. All patients underwent post-RT MRI with T1/T2 sequencing at a median of 3.2 months after RT; 40 patients (80%) underwent functional diffusion-weighted imaging sequences. On initial post-RT MRI, CR was documented in 42 patients (84%), IR in 1 patient (2%), and PR in seven patients (14%). At median followup of 16.3 months, no CR patients had uterine failure. Among eight patients with initial PR/IR, all were found to be clinicopathologically no evidence of disease at the uterus on further evaluation. Conclusions Definitive RT with BT or BT + PRT is associated with high response rates on MRI. Overall, initial CR predicted for excellent outcome with no infield failure.
Why Does Social Class Affect Subjective Well-Being? The Role of Status and Power

The link between social class and subjective well-being (SWB) has been an important topic of inquiry, with broad implications for understanding the psychology of social class and the determinants of SWB. Prior research on this topic has focused primarily on the extent to which social class affects SWB and the factors that moderate that impact. We extend prior work by examining the concerns that account for why social class shapes SWB. In particular, we examine the role of status and power in mediating the impact of one's social class on one's SWB. Across five studies, we theorize and find that status mediates the impact of social class on SWB and, moreover, that status is a stronger mediator of this link than is power. Overall, these studies advance scholarly research on the psychology of social hierarchy by clarifying the interplay between social class, status, and power in relation to SWB.
Abnormal aortic flow conduction is associated with increased viscous energy loss in patients with repaired tetralogy of Fallot.

Objectives Aortopathy in tetralogy of Fallot (TOF) is characterized by increased aortic stiffness, dilation and reduced left ventricular (LV) function. Repair in infancy normalizes aortic dimensions in early childhood. Our prior work demonstrated that early TOF repair does not normalize aortic compliance and that abnormal ascending aortic flow patterns are prevalent. The objectives of this study were to: (i) determine whether proximal aortic flow-mediated viscous energy loss (EL') is elevated in patients with early TOF repair compared with healthy controls, and (ii) determine whether the degree of EL' is associated with LV function. Methods Forty-one patients post TOF repair with normalized aortic size and 15 healthy controls underwent 4-dimenisonal-flow magnetic resonance imaging flow analysis and EL' assessment. Correlations between EL', aortic size, and LV function were assessed. Results The TOF group had increased peak systolic thoracic aorta EL' (3.8 vs 1.5 mW, P = 0.004) and increased averaged EL' throughout the cardiac cycle (1.2 vs 0.5 mW, P = 0.003). Peak and mean systolic EL' in the ascending aorta was increased 2-fold in the TOF group compared with control (peak: 2.0 vs 0.9 mW, P = 0.007). Peak EL' measured along the entire thoracic aortic length correlated with LV ejection fraction (R = -0.45, P = 0.009), indexed LV end-systolic volume (R = -0.40, P = 0.010), and right ventricular end-systolic volume (R = -0.37, P = 0.034). Conclusions Patients with repaired TOF exhibit abnormal aortic flow associated with increased EL' in the thoracic aorta. The magnitude of EL' is associated with LV function and volumes. Increased aortic EL' in TOF is likely due to inherently abnormal LV outflow geometry and or right ventricular interaction. Reduced aortic flow efficiency in TOF increases cardiac work and may be an important factor in long-term cardiac performance.
Hematocrit and Incidence of Venous Thromboembolism

Background. Polycythemia vera patients with high hematocrit have increased risk of venous thromboembolism (VTE). We tested whether high hematocrit in the general population is also associated with elevated VTE risk. Methods. The prospective Atherosclerosis Risk in Communities (ARIC) Study performed a complete blood count in 13,891 adults aged 45-64 at baseline in 1987-89. We identified and validated incident hospitalized VTEs through 2015, with provoked VTE defined as occurring within 90 days of surgery, trauma, immobilization or with cancer. We performed proportional hazards regression analyses using race-sex specific categorization of hematocrit percentiles (i.e., Results. At baseline, higher hematocrit was associated with smoking prevalence, greater pack years smoked, higher body-mass index and higher prevalence of diabetes. With 26 years median follow-up, 800 participants had incident deep vein thrombosis of the leg and/or pulmonary embolism. The figure shows a J-shaped association of hematocrit with VTE incidence. The VTE incidence at the highest level of hematocrit was approximately double that at the mid level. Low hematocrit also was associated with elevated VTE incidence but the confidence interval overlapped 1. The Table shows modeling results. Accounting for other risk factors, the risk of overall VTE was elevated 72% for participants above the 95th percentile of hematocrit compared with the reference. Specifically, hazard ratios (95% confidence interval) of incident VTE were 1.27 (0.91,1.76), 1.06 (0.87,1.28), 1 (reference), 1.17 (0.98, 1.40) and 1.72 (1.30, 2.27) across the five hematocrit percentiles, adjusted for age, race, sex, body mass index, and other potential confounding variables including smoking status and pack-years. The association of high hematocrit with VTE was limited to provoked VTE, with little evidence for unprovoked VTE. Results were similar for hemoglobin (not shown). Discussion. High hematocrit and hemoglobin in a general middle-aged population sample were associated with increased long-term risk of VTE, particularly provoked VTE. The reasons for this pattern require further study. Download : Download high-res image (175KB) Download : Download full-size image Disclosures No relevant conflicts of interest to declare.
The Use of Microcomputers in Education for Librarianship and Information Science.

The advent of microcomputers has made it possible to introduce into the curriculum of library and information science many elements of information science and computer science previously taught descriptively. The results of a survey of the accredited library education programmes in the United States indicate the increasing use of microcomputers in library education, and lead to predictions of even greater use in simulations of systems, programming library applications, statistical analysis of research results, management information systems and tutorial writing.
The effects of sidewall boundary layers in two-dimensional subsonic and transonic wind tunnels

A transonic similarity rule which accounts for the effects of attached sidewall boundary layers in two-dimensional wind tunnels is presented along with results of an experimental investigation of sidewall boundary-layer effects. The rule appears valid provided the sidewall boundary layer both remains attached in the vicinity of the model and occupies a small enough fraction of the tunnel width to avoid substantial three-dimensional interaction with the model.
Net Effect of Young Adult Dual Combusted Cigarette and E-Cigarette Users’ Anticipated Responses to Hypothetical E-Cigarette Marketing Restrictions

Background: Dual use of e-cigarettes and cigarettes is common among young adults. Earlier research has used an internet panel to assess anticipated effects of eliminating nicotine, flavors (except menthol), and customizable e-cigarettes on predicted changes in e-cigarette and cigarette consumption. This earlier analysis showed that all these policies were predicted to lower e-cigarette consumption and increase cigarette consumption among these dual users. The earlier analysis, did not, however, estimate the net effect of these policies considering both lowered and increased consumption. Methods: We computed the net effects of these policies as the difference between people predicting quitting or using cigarettes less and those predicting that they would use them more. The same calculations were done for e-cigarettes. Significance testing was done with z-tests. Results: As expected, the net effect of all three policies was to significantly lower e-cigarette consumption. The net effect was to also lower cigarette consumption for eliminating nicotine and flavors in e-cigarettes, with no significant net effect of eliminating modifiable e-cigarettes. Conclusion: Eliminating nicotine and flavors from e-cigarettes is predicted to lower cigarette as well as e-cigarette consumption.
Broadband Measurement of Quantum Radiation Pressure Noise at Room Temperature

Quantum mechanics places a fundamental limit on the precision of continuous measurements. The Heisenberg uncertainty principle dictates that as the precision of a measurement of an observable (e.g. position) increases, back action creates increased uncertainty in the conjugate variable (e.g. momentum). In interferometric gravitational-wave (GW) detectors, the laser power is increased as much as possible to reduce the position uncertainty created by shot noise , but necessarily at the expense of back action in the form of quantum radiation pressure noise (QRPN) (Caves in Phys Rev Lett 45:75–79, (1980) [1]).
The emergent interactions that govern biodiversity change.

Observational studies have not yet shown that environmental variables can explain pervasive nonlinear patterns of species abundance, because those patterns could result from (indirect) interactions with other species (e.g., competition), and models only estimate direct responses. The experiments that could extract these indirect effects at regional to continental scales are not feasible. Here, a biophysical approach quantifies environment– species interactions (ESI) that govern community change from field data. Just as species interactions depend on population abundances, so too do the effects of environment, as when drought is amplified by competition. By embedding dynamic ESI within framework that admits data gathered on different scales, we quantify responses that are induced indirectly through other species, including probabilistic uncertainty in parameters, model specification, and data. Simulation demonstrates that ESI are needed for accurate interpretation. Analysis demonstrates how nonlinear responses arise even when their direct responses to environment are linear. Applications to experimental lakes and the Breeding Bird Survey (BBS) yield contrasting estimates of ESI. In closed lakes, interactions involving phytoplankton and their zooplankton grazers play a large role. By contrast, ESI are weak in BBS, as expected where year-to-year movement degrades the link between local population growth and species interactions. In both cases, nonlinear responses to environmental gradients are induced by interactions between species. Stability analysis indicates stability in the closed-system lakes and instability in BBS. The probabilistic framework has direct application to conservation planning that must weigh risk assessments for entire habitats and communities against competing interests.
Spontaneous pneumothorax in a single lung transplant recipient-a blessing in disguise: A case report.

Spontaneous pneumothorax in a single lung transplant recipient-a blessing in disguise: A case report
A Sierpiński carpet with the co-Hopfian property

Motivated by questions in geometric group theory we define a quasisymmetric co-Hopfian property for metric spaces and provide an example of a metric Sierpinski carpet with this property. As an application we obtain a quasi-isometrically co-Hopfian Gromov hyperbolic space with a Sierpinski carpet boundary at infinity. In addition, we give a complete description of the quasisymmetry group of the constructed Sierpinski carpet. This group is uncountable and coincides with the group of bi-Lipschitz transformations.
Dynamic Training of a Novelty Classifier Algorithm for Real-Time Early Seizure Onset Detection

The objective of this study was to develop an adaptive framework for seizure detection in real-time that is practical to use in the Epilepsy Monitoring Unit (EMU) as a warning signal, and whose output helps characterize epileptiform activity. Our framework uses a one-class Support Vector Machine (SVM) that is being trained dynamically according to past activity in all available channels. This is done to evaluate the novelty of the current instance according to previous activity. Our algorithm was tested on intracranial EEG from human epilepsy patients that are admitted to the EMU for presurgical evaluation. In this study, we compared multiple configurations for using a one-class SVM to assess if there is significance over specific neural features or electrode locations. Our results show our algorithm is capable of running in real-time and achieving a high performance for early seizure-onset detection with a low false-positive rate and robustness to different types of seizure-onset patterns as well as to the number of channels used. This algorithm offers a solution to warning systems in the EMU as well as a tool for seizure characterization during post-hoc analysis of intracranial EEG data for surgical resection of the epileptogenic network. HighlightsO_LIThis study proposes a dynamic training algorithm that efficiently detects sudden novel changes in intracranial electroencephalographic activity, creating a reliable seizure onset detection algorithm that does not need prior training. C_LIO_LIThe algorithm described has the capability to be implemented in real-time, independently of the number of channels that are being analyzed. C_LIO_LIThe presented detector shows high performance and reliability to be easily implemented in the Epilepsy Monitoring Unit to quickly alert clinical staff of seizure events. C_LI
Advanced Fracture Management Principles of Procedures for Stabilization

Polytrauma patient management includes prompt identification and treatment of fractures and dislocations to stabilize the extremity or joint and reduce further damage to surrounding tissue and structures. Standard treatment includes reduction techniques (both open and closed) with procedures for temporary stabilization until definitive operative fixation can occur. The goal of this chapter is to introduce skeletal traction and external fixation as two methods to achieve closed reduction of fractures and dislocations in the unstable trauma patient. The basic principles and techniques of each will be discussed, as well as considerations, contraindications, and complications.
Towards the ultimate understanding of MUSCL: Pitfalls in achieving third-order accuracy

Abstract We present a proof by analysis and numerical results that Van Leer's MUSCL conservative scheme with the discretization parameter κ is third-order accurate for κ = 1 / 3 . We include both the original finite-volume MUSCL family, updating cell-averaged values of the solution, and the related finite-difference version, updating point values. The presentation is needed because in the CFD literature claims have been made that not κ = 1 / 3 but κ = 1 / 2 yields third-order accuracy, or even that no value of κ can yield third-order accuracy. These false claims are the consequence of mixing up finite-difference concepts with finite-volume concepts. In a series of Pitfalls, we show how incorrect conclusions can be drawn when pointwise values of the discrete solution are interchanged with cell-averaged values. All flawed schemes presented in the Pitfalls, and some correct ones for comparison, are tested numerically and shown to behave as predicted by the analysis. We conclude with firm recommendations on how to achieve third-order accuracy at all output times, or just in a steady state.
A Symphony of Government Design: Imitation in State Constitutions on the Southern Frontier, 1812-1845

The original constitutions of six Southern frontier states are compared: Louisiana's (1812), Mississippi's (1817), Alabama's (1819), Arkansas's (1836), Florida's (1839), and Texas's (1845). Identical or similar elements are examined, and the historical circumstances leading each constitutional convention to adopt this group of provisions are recounted. The duplicated elements include some of the structures of the three branches of government, some individual rights, the methods of choosing seats of government, adaptations to epidemic disease, and means of enforcing fiscal accountability. Primary sources are the constitutions, the constitutional convention journals, territorial papers, and some legislative records, letters, and newspapers. This historical study of constitutional convergence conveniently summarizes parts of antebellum Southern frontier history and also examines the diffusion of a constitutional core of techniques of self-government.
Incobotulinum toxin-A (inco-A) in restless legs syndrome (RLS) - a randomized double blind cross over study (P7.295)

Objective: to study the efficacy of incobotulinum toxin A in relieving the symptoms of RLS and improvement of quality of life. Background: Open studies in small number of patients reported improvement of RLS symptoms after injection of onabotululinum toxin A into tibialis anterior muscle (Rotenberg et al 2007). A more recent blinded study with ona- A on 6 patients however, failed to show improvement (Nahab et al 2008). Design and Methods: Seventeen patients were enrolled and 14 completed the study. The primary outcome was improvement of total IRLS score and quality of life (JohnsHopkins). Secondary outcomes: global impression of change (PGIC), discomfort level measured by visual analogue scale (VAS) at 6 weeks. Patients were injected with Inco-A or saline at baseline and then at 3 months. Patients were rated at baseline, weeks 4, 6, 8, 12, 16, 20 and 24. A total of 40 units was injected into each tibialis anterior and gastrocnemius muscles with an additional 20 units in each hamstring. Results: At 6 weeks, 6 patients in inco-A and 2 patients in the saline group demonstrated significant improvement of IRLS score (P = 0.208). The quality of life improved in 7 patients in inco-A and 1 in the saline group (P=0.03). The level of discomfort (VAS) improved in 8 patients in inco -A and 1 patient in saline group (P=0.01). Eight patients in inco-A and 4 patient in saline group reported satisfaction with treatment in PGIC (P=0.252). Conclusion: Injection of inco-A into tibialis anterior and gastrocnemius muscles (40 units per muscle) improved the quality of life and level of discomfort (measured by VAS) in patients with restless legs syndrome. Disclosure: Dr. Rostami has nothing to disclose. Dr. Machado has nothing to disclose. Dr. Richardson has nothing to disclose. Dr. Jabbari has received research support from Allergan Inc., Merz Pharma, and Ipsen.
A mechanism for the production of ethylene from methional. The generation of the hydroxyl radical by xanthine oxidase.

Ethylene was produced when methional (β-methylthio-propionaldehyde) was incubated under aerobic conditions with milk xanthine oxidase plus xanthine. The accumulation of ethylene under these conditions exhibited a brief lag phase which was overcome by small amounts of hydrogen peroxide. The production of ethylene was inhibited by either superoxide dismutase or by catalase, indicating that both superoxide anion radicals and hydrogen peroxide were required. We have proposed that the hydroxyl radical is the chemical species actually responsible for the production of ethylene from methional and that hydroxyl radicals are generated in the aerobic xanthine oxidase system. This proposal generated several predictions which were experimentally affirmed. 1. Compounds which act as scavengers of hydroxyl radicals inhibited the production of ethylene. 2. Xanthine oxidase acting on limiting amounts of xanthine accumulated less than the theoretical amount of hydrogen peroxide and superoxide dismutase increased the amount of peroxide accumulated. 3. Xanthine oxidase plus ample xanthine reduced cytochrome c to a plateau representing a balance between the reduction of ferricytochrome c by O2- and the oxidation of ferrocytochrome c by ·OH. Scavengers of the hydroxyl radical allowed more nearly complete reduction of cytochrome c. Catalase did likewise. 4. Xanthine oxidase exhibited a xanthine-dependent ferrocytochrome c peroxidase activity which was inhibited by catalase, superoxide dismutase, or by scavengers of the hydroxyl radical. These results have led to the conclusion that xanthine oxidase generates O2- and H2O2 as the primary products of the reduction of oxygen and generates ·OH as a secondary consequence of the interaction of O2- with H2O2 and that it is the hydroxyl radical rather than the superoxide anion radical which reacts with methional to generate ethylene.
Placental transfer of ampicillin.

Abstract Parameters of the transference of ampicillin among the three compartments (mother, fetus, and amniotic sac) have been studied in 103 patients. A rapid transfer occurs from the mother to the fetus, with fetal serum levels reaching levels exceeding minimal inhibitory concentrations for many organisms causing intrauterine infections. The antibiotic appears in the amniotic fluid after 90 minutes; the amniotic fluid compartment appears to form a depot for the sequestration of ampicillin. Varying rates of transfer out of the amniotic fluid are found in different stages of pregnancy and pathologic conditions. The finding of a heat-labile system, inhibitory for the growth of Sarcina lutea , is recorded.
Ultracompliant, passively decoupled thermal probe arrays: large area mapping of non-planar surfaces without force feedback

This paper describes an 8-probe system for scanning thermal microscopy. The design of the probe array, along with the choice of polyimide as the structural material provides very large compliance that virtually eliminates the need for z-axis mechanical feedback both at the chip and probe level in contact mode scans. The high compliance accommodates significant variations in the sample surface, and also prevents damage to soft samples. In addition, since integrated actuators and accompanying circuitry are no longer required, the prospect of scaling to large numbers of probes for high speed, high resolution thermal mapping of large areas with simple detection circuitry is enhanced. Based on single probes fabricated in the same process, the estimated spatial resolution, thermal conductance resolution, and temperature resolution are 50 nm, 11 pW/K, and 1.2 mK respectively. Scalability and performance of the 8-probe prototype are evaluated, addressing issues of speed vs. resolution, thermal and mechanical decoupling. Results demonstrate that contact mode scans can provide better than 2 /spl mu/m spatial resolution at speeds greater than 200 /spl mu/m/sec with each probe.
Microarray analysis reveals differential gene expression in hybrid sunflower species

This paper describes the creation of a cDNA microarray for annual sunflowers and its use to elucidate patterns of gene expression in Helianthus annuus, Helianthus petiolaris, and the homoploid hybrid species Helianthus deserticola. The array comprises 3743 ESTs (expressed sequence tags) representing approximately 2897 unique genes. It has an average clone/EST identity rate of 91%, is applicable across species boundaries within the annual sunflowers, and shows patterns of gene expression that are highly reproducible according to real-time RT–PCR (reverse transcription–polymerase chain reaction) results. Overall, 12.8% of genes on the array showed statistically significant differential expression across the three species. Helianthus deserticola displayed transgressive, or extreme, expression for 58 genes, with roughly equal numbers exhibiting up- or down-regulation relative to both parental species. Transport-related proteins were strongly over-represented among the transgressively expressed genes, which makes functional sense given the extreme desert floor habitat of H. deserticola. The potential adaptive value of differential gene expression was evaluated for five genes in two populations of early generation (BC2) hybrids between the parental species grown in the H. deserticola habitat. One gene (a G protein-coupled receptor) had a significant association with fitness and maps close to a QTL controlling traits that may be adaptive in the desert habitat.
A Rotating Disk Study of the Corrosion Behavior of Cu‐9.4Ni‐1.7Fe Alloy in Air‐Saturated Aqueous NaCl Solution

Results using a rotating disk electrode (RDE) clarify the mechanism of corrosion of commercial Cu‐9.4Ni‐1.7Fe alloy in aerated 3.4 weight percent solution at room temperature. The loosely adherent corrosion product (mainly ) formed under rotating conditions consists of two layers. Additional support is obtained for the existence of a third inner layer which is very thin and adherent to the metal surface. The anodic Tafel slope on this corrosion‐product‐covered sample is 60 mV decade −1 and is independent of rotation speed, consistent with a slow step for the anodic reaction being ionic transport in electrolyte within the porous corrosion‐product layer. Results using Pd deposits on the corrosion‐product surface show that the rate of the cathodic reaction (oxygen reduction) may be under reaction (charge transfer) control rather than transport control through a corrosion‐product inner layer. It follows that the good corrosion resistance of the cupronickels in seawater may be due to a poor catalytic nature of the corrosion‐product surfaces for the oxygen‐reduction reaction.
Attachment of myxoviruses to artificial membranes: electron microscopic studies.

Abstract An artificial lipoprotein membrane consisting of phosphatidylcholine and the glycoprotein fetuin, carrying the specific sialic acid receptor for myxoviruses, has been used in electron microscopic investigations of viral attachment. Techniques of formation and preparation of the membrane for electron microscopy are described. The membrane produced is visualized as a coherent structure approximately 70 A thick, but with no discernible substructure. Myxoviruses (the PR8 strain of influenza A 0 and the Sato strain of Newcastle disease virus) were found to become attached to the membrane, whereas viruses for which the membrane has no specific receptor (adenovirus types 2 and 5, and herpesvirus) were not attached. Membranes formed of sialic acid-free fetuin showed almost complete absence of viral attachment and appeared much thinner. Attachment was also blocked by pretreatment of the membrane with antibody directed against fetuin. Antibody binding studies were made using rabbit antiviral and antifetuin sera, and a goat antirabbit globulin conjugated with ferritin. Binding of antifetuin antibody showed that the membrane had a one-sided structure with virus bound only to the side which accepted antibody, and that soluble fetuin released from the membrane was not responsible for binding of virus aggregates. Ferritin labeling of attached virus showed that the viral envelope remained intact and was not disrupted on contact or incorporated into the membrane. The system offers a means of investigating some current problems involving viruscell interactions.
Formation and stability of mononuclear and dinuclear Eu(III) complexes and their catalytic reactivity toward cleavage of an RNA analog.

The complex between Eu(III) and 1,7-diaza-4,10,13-trioxacyclopentadecane-N,N‘-diacetic acid (L4) was characterized by pH potentiometric titration and 1H NMR spectroscopy. The conversion of the monomer to a dimeric complex is observed as the pH is increased from 7 to 10 in a reaction that releases one mol/HO- per dimer formed. The dimeric complex undergoes a further ionization with a pKa of 10.7. Kinetic parameters are reported for the cleavage of the simple phosphodiester 2-hydroxypropyl-4-nitrophenyl phosphate catalyzed by both the monomeric and the dimeric Eu(III) complexes. These data show that the monomer and dimer stabilize their bound reaction transition states with similar free energies of 7.1 and 7.6 kcal/mol, respectively. Clearly, a bridging hydroxide is not an optimal linker to promote cooperative catalysis between Eu(III) centers in macrocycles with multiple polyaminocarboxylate pendent groups.
Nicotinic acid crown ethers: synthesis, complexation and reduction

Abstract 2, 6-Bis (bromomethyl)nicotinic oxazoline 15, prepared from ethyl 2,6-dimethylnicotinate, was converted into the 1:1-macrocyclic oxazolines 19 and 22 as well as the isomeric macrocyclic dimers 20. Ethyl 2, 6-bis(bromomethyl)nicotinate 23, prepared from 6b, was converted to the corresponding 1:1-dibenzo-18-crown-6 macrocyclic analog 24. NMR and mass spectral data were used to ascertain the macrocyclic structures. Reaction of 22 with EtMgBr afforded, after oxidation, the 4-substituted pyridino macrocycle 26 in high yield. However, under identical conditions, the non-oxazoline macrocycle 27 was recovered in toto.
A Midwestern Response to the Events of September 11, 2001.

ABSTRACT The events of September 11, 2001, seemingly changed the way Americans viewed the world and their sense of vulnerability. What is not clear is the impact 9/11 had on different age groups shortly after the attacks. A quasi-experimental design was employed to study the effects of 9/11 on 298 older and younger adults. Drawing on the work of Leon Festinger, this article explores the role of cognitive dissonance in discussing the reactions of older and younger midwesterners to the events of September 11 as well as their perceptions of President George W. Bush.
Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer's disease

High levels of serum cholesterol and disruptions of the blood brain barrier (BBB) have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer's disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well) were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan's blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer's disease.
The Penems, a New Class of β‐Lactam Antibiotics. 6. Synthesis of 2‐alkylthiopenem carboxylic acids

A synthesis of 2-alkylthiopenems by an intramolecular Wittig-type reaction between a phosphorane and a trithiocarbonate ester is described.
Lattice-statics model for edge dislocations in crystals

A semianalytical lattice-statics model is described for calculating the lattice distortion due to an edge dislocation in a crystal lattice to a desired degree of approximation. The edge dislocation is created by introducing a half-plane of vacancies. The defect space is decomposed into a part that has translation symmetry and a localized end space. The displacement field in the translationally symmetric part is calculated in terms of a constant Kanzaki force that is related to the Burgers vector. The Dyson equation for the defect Green's function is then solved by using a matrix partitioning technique in the localized end space. The technique is illustrated by applying it to a sc lattice model.
Factor Analytic Scales of the Adjective Check List (ACL) Replicated Across Samples: Implications for Validity

In the original item factor analysis of the ACL, evidence was found for seven main factors. In a cross-validation sample, item factor analysis using an altered procedure showed five of the seven factors were replicated. It was concluded that a somewhat stable factor structure of the ACL does exist. However, more factor analyses of this instrument are needed before the factorial validity of the instrument can be established.
Distraction for Pediatric Immunization Pain: A Critical Review

The paper provides a critical review of distraction for pediatric immunizations in order to determine clinical practicality and efficacy of this commonly employed intervention. The MEDLINE and PsycINFO databases were searched to identify papers that included an evaluation of a distraction intervention as a method of pediatric immunization pain management. Fifteen papers were included in this review. Effect sizes were calculated to estimate the clinical significance of findings. In order to examine possible differences in effect sizes related to distraction characteristics, chi square analyses were conducted. Results indicate that distraction is clinically effective in the reduction of pain during pediatric immunizations. Support is found for behavioral and cognitive explanations of distraction mechanisms. Further, various distraction stimulus characteristics were found to be associated with the clinical significance of findings.
An asymptotic approach to transition

A unified theory of large-sized three-dimensional disturbances set up is aimed at developing a dynamical system of transition embracing incompressible fluid as well as subsonic and transonic flows. In appropriately scaled and normalised variables, incompressible and subsonic pulsations obey the same evolution equation for the instantaneous displacement thickness alone. The dynamical system for three-dimensional transonic non-linear waves involves the self-induced pressure as an additional desired function. The notion of the inviscid/inviscid interaction between the upper potential region and an adjustment sublayer at the bottom underlies the theory. In accord with available observational data, the coexistense of organised motion and irregular disturbances is the main conclusion to be drawn from the new asymptotic approach.
The Illusion of Unique Invulnerability and the Use of Effective Contraception

It was proposed that one reason people often fail to use effective contraception methods is that they engage in a systematic distortion of their likelihood of being involved in an unwanted pregnancy relative to others. A survey of undergraduate females found that sexually active women tended to see themselves as less likely than other students, other women their age, and women of childbearing age to become pregnant. The tendency to utilize this illusion of unique invulnerability was related to the use of effective contraception. The more subjects discounted their chances of becoming pregnant relative to others, the less likely they were to use effective methods of birth control.
Physical Conditions in the Orion H ii Region

The Orion Nebula is the defining Galactic H ii region and has been well studied over a broad range of wavelengths. Many of its properties are well established. The gas-phase metallicity is roughly two-thirds of solar, close to that of the star cluster. There is no evidence that grains are destroyed anywhere in the Orion environment; refractory elements such as Ca and Fe remain heavily depleted. If the grains are well mixed with the gas, then the Trapezium cluster's radiation field will drive the gas away, because of the grain opacity. This pushes the grain-bearing gas back against the photodissociation region (PDR). Radiation pressure is more important than winds in controlling the overall geometry. The nebula is in a state of energy equipartition between energy input from starlight and energy stored in gas pressure, kinetic outflow, and the magnetic field. There is much that is not clear, however. How can gas flow away from the PDR into the face of a radiation field that produces such effective radiative acceleration? Grains are photoionized by the stellar radiation field, and this charge establishes a Coulomb drag that couples the grains (which feel the force of the radiation field) to the gas (which has a far lower opacity but most of the mass). The grains drift relative to the gas, with (model dependent) speeds of order a fraction of a km s 1 . The H ii region has a physical thickness of roughly 10 12 km. The grains can drift an appreciable fraction of the thickness of the ionized layer in a timescale of 13 t ! 10 s ≈ yr. The age of the current geometry is unknown since the motion of v 1 Ori C is unknown. The likely 5 10 equilibrium is one where grains drift away from the illuminated face of the H ii region and accumulate near the PDR. The ionized gas, having lost its opacity, then expands into the direction of the central star cluster, loses its emission measure, and eventually becomes invisible. The loss of photoelectric grain heating in parts of the H ii region may cause a dramatic change in electron temperature and provide a natural explanation for the " " 2 t or temperature fluctuations phenomenon. The role of the magnetic field in controlling properties of the H ii region is unclear, although a component of turbulence equal to the Alfven speed has been seen. Clearly much work remains to be done.
THE MURAL PAINTINGS OF EL ZAPOTAL, VERACRUZ, MEXICO

During the 1970s, excavations at El Zapotal revealed a Late Classic period ossuary with multiple burials, sumptuous funerary offerings, and life-sized terracotta sculpture individually on a par with the Chinese national treasures from Xi'an. Less known are murals adorning a U-shaped banquette centering on the monumental clay sculpture of a skeletal Death God.Wyllie, through the assistance of Instituto Nacional de Antropologia e Historia, Veracruz, produced drawings of the now deteriorating paintings. The murals form part of a larger narrative program integrating sculpture, architectural elements, burial offerings, and human osteological remains connected with Mesoamerican underworld stories of creation.
Characterization and Significance of Natural Fractures in Mesaverde Reservoirs at the Multiwell Experiment Site

Natural fractures dominate the permeability of tight gas reservoirs in the Mesaverde Formation of the Piceance Creek Basin, northwestern Colorado. Roughly 450 natural fractures have been detected in reservoir sandstones and siltstones in 4200 ft of core from the US Department of Energy's Multiwell Experiment (MWX). Sixty percent of the fractures are calcite-mineralized, vertical extension fractures that are probably the greatest contributors to reservoir permeability. However, the contribution of the other mineralized fractures should not be discounted. 9 refs., 13 figs.
Discussion forum: The census depository library program

Abstract Of the various depository library programs, the one administered by the Government Printing Office (GPO) is undoubtedly the best known and most frequently mentioned in the literature. Federal legislation and the Office of Management and Budget's Circular A-130 recognize this program as the premier depository program in the United States in providing public access to government publications.1 However, other programs exist (e.g., those of the Geological Survey, Bureau of the Census, and Patent and Trademark Office), and attempts to restructure the GPO's program frequently fail to consider these other depository programs. Perhaps one of the least discussed programs in the literature is the one operated by the Bureau of the Census. The purpose of this essay is to examine the role and importance of the census depository program and to encourage further investigation of non-GPO programs. The insights reported here were gathered from interviews conducted at the Bureau of the Census, an examination of the published literature, and an analysis of the libraries currently participating in the depository program.
Structural adjustment and natural resources in sub‐Saharan Africa: The role of tenure reform

Current critiques of African resource management policies have been influenced by some of the key precepts of World Bank and International Monetary Fund “structural adjustment”; programs, especially the notion that state agencies should play a reduced role in directing and managing economic activity. Many Western donors argue that better resource management will result from policies that extend clearer property rights to users and give greater authority to local institutions, believed to be more accountable to the public. The author agrees with the need for tenure reforms, but argues that devolution of tenure rights and withdrawal of the overbearing state will not alone result in sustainable resource management. Tenure policy needs to be conceived in broad terms, with the aim of achieving an appropriate distribution of rights among all parties with interests in natural resources: farmers, communities, and the state.
Data flow analysis of communicating processes

Data flow analysis is a technique essential to the compile-time optimization of computer programs, wherein facts relevant to program optimizations are discovered by the global propagation of facts obvious locally.This paper extends flow analysis techniques developed for sequential programs to the analysis of communicating, concurrent processes.
Influence of phylogeny on posttranscriptional modification of rRNA in thermophilic prokaryotes: the complete modification map of 16S rRNA of Thermus thermophilus.

Posttranscriptional modification in RNA generally serves to fine-tune and regulate RNA structure and, in many cases, is relatively conserved and phylogenetically distinct. We report the complete modification map for SSU rRNA from Thermus thermophilus, determined primarily by HPLC/electrospray ionization MS-based methods. Thermus modification levels are significantly lower, and structures at the nucleoside level are very different from those of the archaeal thermophile Sulfolobus solfataricus growing in the same temperature range [Noon, K. R., et al. (1998) J. Bacteriol. 180, 2883−2888]. The Thermus modification map is unexpectedly similar to that of Escherichia coli (11 modified sites), with which it shares identity in 8 of the 14 modifications. Unlike the heavily methylated Sulfolobus SSU RNA, Thermus contains a single ribose-methylated residue, N4,2‘-O-dimethylcytidine-1402, suggesting that O-2‘-ribose methylation in this bacterial thermophile plays a reduced role in thermostabilization compared with th...
Short‐Term Elemental Mercury Exposures at Three Arizona Schools: Public Health Lessons Learned

Acute exposure of schoolchildren to elemental mercury continues to produce public health crises that drain available health and environmental resources. In this retrospective study, we report three incidents of limited exposure to elemental mercury in Arizona schoolchildren. Health workers screened 347 students, family, and staff by history and physical exam for exposure level and symptomatology. Urine and blood mercury testing further evaluated at-risk individuals. Environmental contamination was also assessed. Despite up to 28% of patients reporting symptoms, no individual was found to have elevated serum or urinary mercury levels requiring treatment. Elevated airborne mercury levels were demonstrated in the classrooms, dormitories, buses, and student homes and appropriate clean-up measures were instituted. Previous studies of multiple exposures to elemental mercury either focus on significant patient morbidity or lack biological data. In contrast, this study reports biological and environmental data demonstrating no clinical toxicity following acute exposure in a large sample. Confirmatory studies are necessary to develop cost-effective guidelines for the appropriate management of these public health crises.
CHARGE ASYMMETRIC DISSOCIATION INDUCED BY SEQUENTIAL AND NONSEQUENTIAL STRONG FIELD IONIZATION

Charge asymmetric dissociation (CAD) is observed, for the first time, with near-infrared 30 fs laser pulses, in small molecules, ${\mathrm{N}}_{2}$ and ${\mathrm{O}}_{2}$. ${\mathrm{N}}_{2}^{2+}$ is created by a nonsequential (vertical) transition and the dissociation fragments appear to be in excited states. Unlike ${\mathrm{N}}_{2}$, ${\mathrm{O}}_{2}^{2+}$ involves a sequential (nonvertical) transition. The charge asymmetric dipole coupling to the external field is insufficient to populate the charge transfer states leading to CAD. Rather, CAD is a natural result of strong field excitation and ionization. These results in the tunneling regime are also compared with previous experiments performed with UV radiation in the multiphoton regime.