cssi/SciSciGPT-SciSciNet huggingface dataset:
Regulation of pancreatic duct cell differentiation by phosphatidylinositol-3 kinase.

We have previously demonstrated that the phosphatidylinositol-3 kinase (PI3K)/Akt signaling is essential for pancreatic regeneration after partial pancreatectomy in mice. In the present study, we examined a role of PI3K/Akt signaling for pancreatic duct cell differentiation into insulin-producing cells. Epithelial-like cells were isolated from mouse pancreas and confirmed to be positive for a duct cell marker cytokeratin-20 (CK-20) but negative for insulin. Incubation of these cells with epidermal growth factor, exhibited a gradual increase in Akt phosphorylation and expression of pancreatic duodenal homeobox-1 (PDX-1), a regulator of β-cell differentiation. Three weeks later, these CK-20-positive cells were noted to express insulin as determined by immunofluorescent double-staining. Akt phosphorylation, PDX-1 expression, and insulin production were effectively reduced by blocking the PI3K/Akt pathway using siRNA to the p85α regulatory subunit of PI3K. Our results demonstrate that PI3K/Akt activation has a critical role for pancreatic duct cell differentiation into insulin-producing cells.
Virtual separation approach to study porous ultra-thin films by combined spectroscopic ellipsometry and quartz crystal microbalance methods

Abstract Spectroscopic ellipsometry (SE) and quartz crystal microbalance with dissipation (QCM-D) techniques have been extensively used as independent surface characterization tools to monitor in-situ thin film formation. They provide different information for ultra-thin films because QCM-D is sensitive to the solvent content while SE is not. For using these two techniques in tandem, we present a virtual separation approach to enable the determination of both ultra-thin film thickness and porosity. Assumptions for the intrinsic molecular polarizability (index of refraction n o ) and density ( ρ o ) of the organic adsorbent must be made, and the consequences for these parameters' values are discussed.
Effect of decreased oxygen on in vitro release of endogenous 3,4-dihydroxyphenylethylamine from mouse striatum.

: The effects of hypoxia on release of endogenous 3,4-dihydroxyphenylethylamine (DA, dopamine) were investigated in mouse striatal slices. Following a 60-min pre-incubation, potassium increased DA release 12 times between zero and 1 min. By 10 min, uptake processes exceeded release and DA levels in the media decreased. Hypoxia (low oxygen) and anoxia (no oxygen) increased DA in the media by 120 and 205%, respectively, but did not alter dihydroxyphenylacetic acid concentrations. Under similar conditions, anoxia increased [3H]DA uptake eightfold. For the uptake studies, the amount of DA added to the media was critical; in the presence of high concentrations of DA, anoxia reduced reuptake. Regardless of exogenous DA, hypoxia and anoxia increased extracellular DA, which may play a role in ischemic cell damage.
Lifetime measurements in the excited S states of K, Rb, and Cs by the cascade Hanle effect*

The cascade Hanle-effect technique has been described in detail. It has been used to measure the radiative lifetimes of several excited S states in heavy alkali metal atoms. We obtained the following measurements (in nanoseconds): τ(K, 6 2S1/2) = 68 ± 9, τ(Rb, 7 2S1/2) = 91 ± 11, τ(Cs, 8 2S1/2) = 96 ± 14, and τ(Cs, 9 2S1/2) = 231 ± 35.
Electric fields and wound healing

Abstract There are many points of view from which one may consider the healing of wounded skin, several of which are dealt with in earlier chapters. We would like to focus on one aspect of wound healing that has received only scant attention: the possible role of electric fields in the migration of epithelial cells that must occur in order to heal wounded skin. This cell migration is one of the earliest signs of epithelial repair of epidermal wounds, both in mammals and in amphibians. 1 One important reason for the lack of attention to electrical aspects of skin healing can be attributed to the paucity of information, useful to an understanding of wound healing, about the mammalian skin's ability to generate electrical currents. The bulk of the literature on the electrical properties of mammalian skin is concerned with psychophysiology. 2 4 There is some information about electrical properties of skin that may be relevant to wound healing. Some years ago, Herlitzka 5 confirmed DuBois-Reymond's 1860 observation 6 that about 1 microampere of current leaves small epidermal wounds made in human fingers when the wounds are immersed in saline. Much more recently. Illingworth and Barker 7 have found currents with densities ranging from 10 to 30 μA/cm 2 leaving the stumps of accidentally amputated children's fingertips when the stumps are immersed in saline. We, working with Barker, have added to this information 8 by studying the current-generating capacity of the glabrous epidermis of the cavy, and, particularly, the gradients of electrical potential that exist in the vicinity of wounds made in such skin. Subsequently, we have begun study of wound healing in a simpler system, larval Xenopus skin. We here will review this information, present some previously unpublished observations, and speculate on the possible relevance of this information to wound healing.
REGRESSION METHODOLOGY WITH GROSS OBSERVATION ERRORS IN THE EXPLANATORY VARIABLES

The robustness of linear programming regression estimators is examined where the disturbance terms are normally distributed and there are observation errors in the explanatory variables. These errors are occasional gross biases between one set of observations and another. The simulation of short series data offers preliminary evidence that when these biases have a non-zero mean, MSAE estimation is more robust than least squares.
Geospace electrodynamic connections

Abstract As part of NASA's Solar Terrestrial Probe (STP) line of spacecraft, the planned Geospace Electrodynamic Connections (GEC) mission is designed to finally explore in depth the intricacies of electrodynamic coupling processes in the lower ionosphere, where magnetospheric processes couple with the thermosphere. It is currently envisioned as a 4-spacecraft (identically instrumented) mission, which will measure all relevant in situ plasma and neutral atmosphere parameters with the option of including remote observations for a wider perspective. The parking orbits will be 200X2000 km with weeklong dipping campaigns planned down below 130 km where the neutral atmosphere begins to dominate the dissipation of plasma energy and momentum. Each spacecraft will carry hundreds of kilograms of propellant to enable deep dipping campaigns and to have the maneuverability to investigate a broad spectrum of relevant electrodynamic coupling scale sizes. Thruster firings will be used to provide different spacings between spacecraft - either along a common pearls-on-a-string configuration, or by separating the planes of the orbits in local time, or by relative changes in the latitude of the argument of perigee. GEC has the exciting potential for resolving many of the uncertainties in our understanding of the ionosphere as an inseparable part of the electrodynamic physics chain connecting the sun's magnetoplasma with the Earth's upper atmosphere.
A High Efficiency Frequency Doubler for 100 GHz

Development of a high efficiency varactor frequency doubler for 100 GHz is reported. The efficiency of the doubler is greater than 32% at any frequency between 97 GHz and 102 GHz and reaches 35% at 98 GHz. This is the highest efficiency ever reported for a frequency multiplier above 75 GHz. The measured efficiency is in very good agreement with a theoretically predicted value. The doubler is very suitable for the realization of a W-band, all solid-state, local oscillator source.
Chromosomes of Lemuriformes. IV. Karyotype evolution in Lemur fulvus collaris (E. Geoffroy 1812)

The G-banded karyotype of a feral Lemur fulvus collaris has a diploid number of 52; the nombre fondamental is 64. The karyotype consists of 6 pairs of biarmed autosomes, 19 pairs of acrocentric autosomes, and acrocentric sex chromosomes. Comparisons of the 2N = 52 complement with the 2N = 50 and 2N = 51 karyotypes published by Hamilton et al. ('77) supports the view that hybridization occurs naturally between animals with diploid numbers of 50 and 52.
Provider Education To Promote Implementation of Clinical Practice Guidelines

Study objectives Although the interest in and promulgation of clinical practice guidelines have significantly increased in the past 2 decades, concern exists about their actual implementation. This article focuses on one strategy to encourage guideline implementation at the clinician level: clinician education. The objectives of the article are to review educational strategies, to consider them within the context of complementary strategies carried out at the organizational and clinic setting levels, and to outline challenges and recommendations for clinicians' continuing education. Methods Experience and data from relevant randomized clinical trials within an educational framework are reviewed. Observations Implementation of clinical practice guidelines requires a variety of skills, including assessment, appropriate delineation of a treatment and monitoring plan, patient tracking, and patient counseling and education skills. Continuing education strategies must reflect the content and teaching methods that best match the learning objectives. The pressures of current-day practices place limits on the resources, particularly clinician time, that are available for continuing education. Organizational resources must be committed to build the complementary supportive systems necessary for improved clinician practice. In addition to physicians, education must be directed at nonphysician clinicians, office staff, and administrators who also are responsible for guideline implementation. Conclusions To meet the challenges of developing clinician motivation, balancing competing demands, and treating patients with complex medical conditions, all within time constraints, clinical leaders need to design education activities that have leadership support, reflect compelling evidence, use multiple strategies and teaching techniques, and engage learners in skill building and problem solving.
Human CCAAT-binding proteins have heterologous subunits

Abstract We have characterized three distinct proteins present in HeLa cell extracts that specifically recognize different subsets of transcriptional elements containing the pentanucleotide sequence CCAAT. One of these CCAAT-binding proteins, CP1, binds with high affinity to CCAAT elements present in the human a-globin promoter and the adenovirus major late promoter (MLP). A second protein, CP2, binds with high affinity to a CCAAT element present in the rat γ-fibrinogen promoter. Finally, the third CCAAT-binding protein is nuclear factor I (NF-I), a cellular DNA-binding protein that binds to the adenovirus origin of replication and is required for the initiation of adenoviral replication. CPi, CP2, and NF-I are distinct activities in that each binds to its own recognition site with an affinity that is at least three orders of magnitude higher than that with which it binds to the recognition sites of the other two proteins. Surprisingly, CP1, CP2, and NF-I each appear to recognize their binding site with highest affinity as a multisubunit complex composed of heterologous subunits. In the case of CP1, two different types of subunits form a stable complex in the absence of a DNA-binding site. Moreover, both subunits are present in the CP1-DNA complex. We thus propose the existence of a family of related multisubunit CCAAT-binding proteins that are composed of heterologous subunits.
Optimization of lateral-directional dynamics for an aircraft operating at high angle of attack

In this paper, the control laws for the lateral-directional dynamics of a supermaneuverable aircraft is analyzed with a view to reducing the levels of lateral acceleration and sideslip, which are encountered during aggressive rolling maneuvers at high angles of attack. The analysis uses a linearized model of the lateral-directional dynamics and thus H-free-flow techniques can be applied. It is shown that trade-offs exist between simultaneously minimizing lateral acceleration measured at the pilot's station, ny(p), minimizing sideslip and minimizing tracking errors between the roll-rate about the velocity vector and its command. The paper concludes that a significant reduction in ny(p) is only attainable by compromising the roll-rate performance.
Perioperative Myocardial Infarction: A Diagnostic Dilemma

Patients undergoing coronary bypass grafting were studied for incidence of perioperative myocardial infarction (MI) using three modalities: serial electrocardiograms (ECG), serial creatine phosphokinase isoenzymes (MB-CPK), and serial technetium 99m-labeled pyrophosphate scans. A definite perioperative MI was diagnosed if the results were positive in two of the three variables studied. The perioperative infarction rate for the entire group was 8%. The operative mortality was 2.9%. Seven of 8 perioperative MIs were diagnosed by the use of scanning alone. The combination of isoenzyme and ECG analysis diagnosed 5 of 8 perioperative MIs. The MB-CPK and ECG studies were associated with a higher incidence of false-positive diagnoses than myocardial scanning. Patients with perioperative MI had a benign clinical course. Justification for performing three routine 99mTc-pyrophosphate scans on all patients undergoing aortocoronary bypass operation is still to be determined.
Fair bandwidth allocation framework for heterogeneous multi-radio Wireless Mesh Networks

To reap the benefits of advances in wireless technologies as well as provide backward compatibility with current investments, future wireless routers that constitute the backbone of Wireless Mesh Networks (WMNs) will be equipped with multiple radios of different technology standards. The multiplicity of channels, radios and technology standards makes the problem of efficient network utilization in a WMN more challenging. Unlike previous works that focused only on homogeneous WMNs, in this paper, we focus on determining an effective routing, channel assignment and scheduling scheme that maximizes the network capacity, while maintaining node level fairness in a heterogeneous network setting. We first introduce a novel graph model that captures the WMN heterogeneity in terms of the number of radios and radio technologies. Using this model, we provide an optimization formulation that determines the effective routing scheme and traffic values on each edge. To determine an interference-free channel assignment of these traffic values, we introduce a joint channel assignment and scheduling algorithm that preserves node level fairness. We perform an extensive evaluation of our solution in homogeneous and heterogeneous networks and study the impact of the number of orthogonal channels, radios, gateways and the aggregate traffic demand on the performance of our solution. Our results show that the proposed scheme obtains node level fairness while maximizing the network capacity.
Transcriptional Activators Enhance Polyadenylation of mRNA Precursors

Summary Polyadenylation of mRNA precursors is frequently coupled to transcription by RNA polymerase II. Although this coupling is known to involve interactions with the C-terminal domain of the RNA polymerase II largest subunit, the possible role of other factors is not known. Here we show that a prototypical transcriptional activator, GAL4-VP16, stimulates transcription-coupled polyadenylation in vitro. In the absence of GAL4-VP16, specifically initiated transcripts accumulated but little polyadenylation was observed, while in its presence polyadenylation was strongly enhanced. We further show that this stimulation requires the transcription elongation-associated PAF complex (PAF1c), as PAF1c depletion blocked GAL4-VP16-stimulated polyadenylation. Furthermore, knockdown of PAF subunits by siRNA resulted in decreased 3′ cleavage, and nuclear export, of mRNA in vivo. Finally, we show that GAL4-VP16 interacts directly with PAF1c and recruits it to DNA templates. Our results indicate that a transcription activator can stimulate transcription-coupled 3′ processing and does so via interaction with PAF1c.
Pax2/8 proteins coordinate sequential induction of otic and epibranchial placodes through differential regulation of foxi1, sox3 and fgf24

Vertebrate cranial placodes contribute vitally to development of sensory structures of the head. Amongst posterior placodes, the otic placode forms the inner ear whereas nearby epibranchial placodes produce sensory ganglia within branchial clefts. Though diverse in fate, these placodes show striking similarities in their early regulation. In zebrafish, both are initiated by localized Fgf signaling plus the ubiquitous competence factor Foxi1, and both express pax8 and sox3 in response. It has been suggested that Fgf initially induces a common otic/epibranchial field, which later subdivides in response to other signals. However, we find that otic and epibranchial placodes form at different times and by distinct mechanisms. Initially, Fgf from surrounding tissues induces otic expression of pax8 and sox3, which cooperate synergistically to establish otic fate. Subsequently, pax8 works with related genes pax2a/pax2b to downregulate otic expression of foxi1, a necessary step for further otic development. Additionally, pax2/8 activate otic expression of fgf24, which induces epibranchial expression of sox3. Knockdown of fgf24 or sox3 causes severe epibranchial deficiencies but has little effect on otic development. These findings clarify the roles of pax8 and sox3 and support a model whereby the otic placode forms first and induces epibranchial placodes through an Fgf-relay.
On Imitation to Innovation: The Dynamics of Korea's Technological Learning

How does a nation transform itself from an imitative one to an innovative one? This is a challenge that most catching-up countries face as they make their way up the ladder in the world economy. In...
Collisional activation mass spectra of pentene and hexene molecular ions

The collisional activation spectra of the molecular ions from fourteen pentene and hexene isomers show substantial differences, some of which can be rationalized using known ion fragmentation mechanisms. These differences, and their negligible dependence on ion internal energy, are advantageous for the structural characterization of such isomeric ions, including those produced by fragmentation of larger molecules. The decompositions of metastable ions of the pentenes were nearly identical, but those of the hexenes showed some differences useful for structural charactrization.
Measuring the social rate of return to R&D in coal, petroleum and nuclear manufacturing: A study of the OECD countries

This paper estimates the social rate of return to research and development (R&D) in the energy manufacturing industry. Our model tries to quantify the positive contribution that lagged R&D has on total factor productivity (TFP) growth in the manufacturing of coal, petroleum products and nuclear fuel for a number of OECD countries. Using a panel of data from the OECD STAN database we are able to obtain results suggesting that R&D has a positive and significant rate of return that varies for each country.
Acupuncture reduces the trigeminal evoked response in decerebrate cats

Abstract Electroacupuncture was administered to 52 decerebrate, unanesthetized cats in which the trigeminal electrically evoked response was recorded from the surface of the brain stem. In 15 of these, the first negative wave of the evoked potential was reliably depressed by 20 to 80% after electroacupuncture, and spontaneous recovery of the responses occurred in 3 to 15 min. This is a previously unreported finding and is discussed in the light of current theories of acupuncture and analgesia.
Changes in Right Ventricular Structure and Function Assessed Using Cardiac Magnetic Resonance Imaging in Bosentan-Treated Patients With Pulmonary Arterial Hypertension

Patients with pulmonary arterial hypertension (PAH) usually show improvements in symptoms, exercise capacity, and hemodynamics after treatment with approved medical therapies. This study sought to determine whether improvement in right-sided cardiac function measured using cardiac magnetic resonance imaging would also be seen and whether these changes would correlate with improvement in exercise capacity. Sixteen patients with PAH underwent evaluation at baseline and after 12 months of treatment with bosentan. After treatment, cardiac index, pulmonary vascular resistance, and 6-minute walk distance improved, and there was a trend toward improvement in right ventricular (RV) stroke volume (70 ± 27 to 81 ± 30 ml; p = 0.08), but no change in RV ejection fraction (RVEF) or RV end-diastolic volume. Six-minute walk distance improved by 59 m (p
Asymmetric syntheses of a GPR40 receptor agonist via diastereoselective and enantioselective conjugate alkynylation

Abstract Two asymmetric methods to synthesize a potent GPR40 receptor agonist are reported. Both synthetic routes utilize readily available, inexpensive starting materials and reagents. The first route relies on a highly diastereoselective conjugate alkynylation of an ephedrine-derived oxazepanedione acceptor. The second route features the enantioselective alkynylation of a Meldrum’s acid-derived acceptor mediated by a chiral zinc cinchonidine reagent.
Ecstasy (MDMA) exposure and neuropsychological functioning: A polydrug perspective

Ecstasy (MDMA) is a popular drug that can act as a selective serotonin neurotoxin in several species. The goal of the present study was to examine the relationship between ecstasy exposure and cognitive functioning after controlling for other drug use and demographic variables. Furthermore, we assessed whether gender was a moderator of the relationship between cognitive functioning and ecstasy use. Data were collected from 31 men and 34 women with a wide range of ecstasy use (17 marijuana users with no ecstasy use and 48 ecstasy users ranging from low to heavy use). Participants were interviewed and administered a battery of neuropsychological tests. The primary finding was that ecstasy exposure was significantly related to poorer verbal learning and memory ability in a dose-dependent manner, while no such relationship was observed between ecstasy exposure and executive functioning or attentional ability. Gender was found to significantly moderate the relationship between ecstasy consumption and design fluency. These results suggest primary memory dysfunction among abstinent recreational ecstasy users. This finding is consistent with reports of hippocampal vulnerability, particularly among heavy users.
Toward prevention of alcohol exposed pregnancies: characteristics that relate to ineffective contraception and risky drinking

Alcohol-exposed pregnancy is a leading cause of preventable birth defects in the United States. This paper describes the motivational patterns that relate to risky drinking and ineffective contraception, two behaviors that can result in alcohol-exposed pregnancy. As part of an intervention study aimed at reducing alcohol-exposed pregnancy 124 women were recruited and reported demographic characteristics, readiness to change, stages of change, drinking, contraception, and sexual behavior history. Our results showed the following. Drinking: A significant positive correlation was found between the number of drinks consumed in 90 days and the Importance to reduce drinking (r = .23, p = .008). A significant negative correlation between number of drinks and confidence to reduce drinking (r = −.39, p = .000) was found as well. Significant differences were found in the total number of drinks consumed in 90 days between the five stages of change (F = (4,118), 3.12, p = .01). Women in Preparation reported drinking a significantly higher number of drinks than women in other stages of change. Contraception: There were significant negative correlations between ineffective contraception and Importance (r = −.38, p = .00), confidence (r = −.20, p = .02) and Readiness (r = −.43, p = .00) to use contraception effectively. Significant differences in contraception ineffectiveness were found for women in different stages of change (F = (4,115) 8.58, p = .000). Women in Precontemplation reported significantly higher levels of contraception ineffectiveness compared to women in other stages of change. Results show a clear relationship between higher alcohol consumption and higher levels of motivation to reduce drinking. In contrast, higher levels of ineffective contraception were related to lower levels of motivation to use contraception effectively. This suggests risky drinking may be better targeted with brief skills building interventions and ineffective contraception may require interventions that enhance problem awareness and motivation.
Supportive Networks: Life Ties for the Elderly

Recent studies suggest that the increased vulnerability of the older person to physical and/or mental breakdown is related to loss or deficiency in the pattern of supportive ties. With increases in the geographical separation of adult children from their parents, and with greater longevity, the needs of the elderly are increasingly being transferred from the family either to public service settings or to voluntary associations. The resource needs depend in part on the individual's existing contacts and state of health, as well as upon the psychological history of the person. Various programs have addressed the differences in social support for older people in markedly different ways. Six different programs are examined to illustrate the importance of attention to health status, ethnicity, and style of life in the provision of social support. By evaluating the offerings of these programs against the concepts of network theory we are able to show how the needs for social support among the elderly are highly differentiated and deserving of equally differentiated forms of response.
Backscatter and attenuation imaging from ultrasonic scanning in medicine

Images of backscatter, attenuation, and frequency dependence of attenuation are obtained based on a three-parameter model and computation techniques described in this paper. There are several critical sources of error: backscatter speckle, beamwidth distortion, and cross-coupling artifacts between attenuation and backscatter. An iterative method of imaging and filtering is developed which effectively reduces these errors. Stability of the numerical solution involving the large number of unknowns is obtained by image iteration as opposed to parameter iteration along individual transmitter rays. This method incorporates three basic functional aspects: (1) multiple scans to reduce speckle, beamwidth distortions, and certain cross-coupling artifacts, (2) pre-image filtering to decrease beam distortions and post-image filtering to reduce cross-coupling artifacts, and (3) proper sequencing of image reconstruction and filtering. Backscatter images formed by this image iteration method are significantly superior to standard B-scan images. Further, the image iteration method yields three images of the same scan field. The present investigation is based on simulated echo data from cyst-like and complex targets.
Auditory and visual hallucinations in a sample of severely mentally ill Puerto Rican women: an examination of the cultural context

The content, interpretation, and structure of hallucinations experienced by individuals with severe mental illness are influenced by the culture of the individuals who experience them. We analyzed the content of visual and auditory hallucinations of 53 Puerto Rican women in northeastern Ohio with a diagnosis of a severe mental illness (SMI) who were participating in a study of HIV risk among Hispanic women with SMI. Compared to non-hallucinators, hallucinators had lower global assessment of functioning scores and greater suicidality. Hallucinations reflected three themes: religious themes, command hallucinations, and unidentifiable voices. Hallucinators’ subjective experience of their hallucinations ranged from a sense of security to significant distress. Participants developed a wide range of strategies to deal with threatening hallucinations. Provider response to individuals’ experience appeared to impact the quality of the patient–provider relationship. We recommend the inclusion of religious history i...
Unidirectional crystallization of potassium disilicate II. Experimental study

Abstract Directional crystallization of a glass consisting of 61.1 wt% SiO 2 and 38.9 wt% K 2 O was achieved by translating the sample through a temperature gradient of 13°C/mm. Translation rates of 0.8, 1.33 and 5 mm/h were tried in conjunction with starting temperatures ranging from 800 to 1000°C. Good morphological and crystallographic alignment was obtained with 1.33 mm/h and 950°C. The microstructure of samples prepared using these conditions was examined with reflected and transmitted light microscopy, SEM and X-ray diffraction. The crystals were identified as potassium disilicate lamellae; these were several mm in height, about 1 mm wide and 0.05 mm thick. The crystal growth rate was measured for two translation rates by quenching the sample after specified times of heat treatment.
Global Good Samaritans: When do we Heed 'the Responsibility to Protect'?

What is the current outlook for the creation of humanitarian interventions? Can the normative advancement of 'the responsibility to protect' (R2P) translate into actual humanitarian commitments? This paper surveys the prospects for the realisation of R2P given the post-11 September 2001 environment. Human need and legal progress are not the only factors driving international humanitarianism and the idea of a 'responsibility to protect'. Moreover, we know that humanitarian interventions are not conducted as discreet impulses. To map the variety of factors that influence the creation of humanitarian operations, this article suggests a preliminary model to assist in charting when international and domestic environments are conducive to the creation of a specific humanitarian intervention. To survey the likelihood of implementing a 'responsibility to protect', the paper identifies several relevant factors that are important for the realisation of 'global Good Samaritan' operations.
Activation of unsaturated alkyl chlorides by photogenerated [Pd(CNMe)3].+ radicals. Transient absorbance kinetics studies of the formation of η3-allyl and “oxaallyl” palladium complexes

Abstract The reactions of photogenerated [Pd(CNMe)3].+ radicals with the unsaturated alkyl chlorides, RCl = allyl chloride and chloroacetone, have been investigated by laser flash photolysis. Irradiation (λ > 290 nm) of acetonitrile solutions of [Pd2(CNMe)6][PF6]2 (1), in the presence of allyl chloride yields a mixture of the η3-allyl complex [Pd(C3H5)(CNMe)2][PF6] and [PdCl(CNMe)3][PF6]. In the presence of chloroacetone, Cl-atom abstraction by photogenerated [Pd(CNMe)3].+ radicals yields the “oxaallyl” complex [Pd(CH2C(O)Me)(CNMe)2][PF6] and [PdCl (CNMe)3][PF6]. The disappearance of 1 in the presence of RCl occurs with a limiting quantum yield of 0.07 ± 0.01 (R  C3H5) and 0.05 ± 0.01 (R  MeC(O) CH2) at 313 nm. The rate of disappearance of [Pd(CNMe)3].+, generated by laser flash photolysis (355 nm), depends on [RCl]. The reaction is first-order over the concentration range 0.062–1.23 M for allyl chloride and 0.63–1.89 M for chloroacetone. The rate constants for the bimolecular reactions with allyl chloride and chloroacetone are 500 and 200 M−1 s−1, respectively. Mechanisms for the reactions of photogenerated [Pd(CNMe)3].+ with allyl chloride and chloroacetone are interpreted in terms of rate limiting Cl-atom abstraction to form [PdCl(CNMe)3][PF6] followed by rapid combination of a second [Pd(CNMe)3].+ radical with the resulting allylic radical.
A Multilevel Framework Exploring Domestic Violence Against Immigrant Indian and Pakistani Women in the United States

The purpose of this study was to gather preliminary data about the experience of domestic violence from the perspective of immigrant Indian and Pakistani women residing in the United States. Using hierarchical linear regression, we explored the association between individual-, familial-, and cultural-level variables and the experience of domestic violence as assessed by the four aggression subscales of the Revised Conflict Tactics Scale. Our sample consisted of 78 women who were Indian, residents of Illinois, between 18 and 35 years old, college educated, and employed. Most of the women were married. Results showed a 77% prevalence rate and a 71% incidence rate for the experience of domestic violence for the women in our sample. Results of the hierarchical linear regression analysis indicated that level of education, employment status, domestic violence among immediate and extended family members, and cultural belief in male domination were significantly associated with domestic violence.
Implantation by electrophysiologists of 100 consecutive cardioverter defibrillators with nonthoracotomy lead systems.

BACKGROUND Traditional lead systems for implantable cardioverter defibrillators (ICDs) require a thoracotomy for placement. Nonthoracotomy lead systems are available and are usually implanted by an electrophysiologist and a surgeon. The purpose of this study was to prospectively evaluate the safety and efficacy of ICD implantation with a nonthoracotomy lead system by electrophysiologists. METHODS AND RESULTS A consecutive series of 100 patients (mean age, 61 +/- 13 years, +/- SD) underwent ICD implantation with a nonthoracotomy lead system while intubated and under general anesthesia. Seventy-seven patients had coronary artery disease, 15 had idiopathic cardiomyopathy, 6 had miscellaneous heart disease, and 2 had structurally normal hearts. The mean ejection fraction was 0.29 +/- 0.13. Sixty-eight patients had suffered a cardiac arrest, and 32 had had ventricular tachycardia or syncope. All patients except 9 underwent electrophysiological testing and had failed 1 +/- 1 drug trials before ICD implantation. Three types of nonthoracotomy lead systems were used. The nonthoracotomy lead with an ICD was successfully implanted in 96 patients (96%). Of the unsuccessful implants, 1 patient did not have venous access, the passive fixation lead in 1 would not remain lodged, 1 had elevated defibrillation thresholds, and 1 developed a hemopneumothorax while venous access was being obtained. The mean defibrillation threshold was 17 +/- 6 J. The mean procedure duration was 161 +/- 57 minutes. When a subcutaneous patch was used (n = 58), the procedure duration was 189 +/- 5 minutes, and when a subcutaneous patch was not required (n = 40), the procedure lasted 123 +/- 37 minutes (P CONCLUSIONS (1) Electrophysiologists can implant an ICD with a nonthoracotomy lead system safely and with a high success rate; (2) use of a subcutaneous patch correlates with longer procedure durations; and (3) special precautions should be taken in patients with previous abdominal surgery.
Magnetic Field Structure Associated with Coronal Streamers.

Magnetic field structure associated with coronal streamers observed during solar eclipse of May 30, 1965
Gamma-ray astronomy using a high pressure gas scintillation drift chamber with a waveshifting fiber readout

We describe a balloon-borne hard X-ray telescope called SIGHT (Scintillation Imaging Gas-filled Hard X-ray Telescope). SIGHT is a high sensitivity, good energy resolution instrument that images in the 30 to 300 keV region. We discuss the development of a large area, 20 atmosphere, position sensitive xenon gas scintillation drift chamber which is the gamma-ray detector at the heart of the telescope package. Results of the development of the novel waveshifting fiber readout for this chamber are presented.
Strain rate sensitivity of hydroxyapatite coatings

Abstract The strain-rate sensitivity of strength is a significant factor to evaluate the deformation mode of crystalline materials. The strain rate sensitivity of hardness is experimentally investigated here for hydroxyapatite coatings that are sputter deposited onto titanium-coated silicon wafers. These biocompatible HA coatings can provide a strong, dense interface between metal alloy implants and porous hydroxyapatite that can help in-growth of tissue. The interface to the metal alloy implant is important to transfer stress during loading. So, it is very important to know the behavior of the coating under different conditions of loading. Our dynamic test procedure now takes advantage of nanoscratch testing to measure the change in scratch hardness of the coating over a strain rate range that may well simulate the mechanical loading conditions found at the interface between implants and hydroxyapatite coatings.
Glucocorticoid signaling defines a novel commitment state during adipogenesis in vitro.

Differentiation of 3T3-L1 preadipocytes can be induced by a 2-d treatment with a factor “cocktail” (DIM) containing the synthetic glucocorticoid dexamethasone (dex), insulin, the phosphodiesterase inhibitor methylisobutylxanthine (IBMX) and fetal bovine serum (FBS). We temporally uncoupled the activities of the four DIM components and found that treatment with dex for 48 h followed by IBMX treatment for 48 h was sufficient for adipogenesis, whereas treatment with IBMX followed by dex failed to induce significant differentiation. Similar results were obtained with C3H10T1/2 and primary mesenchymal stem cells. The 3T3-L1 adipocytes differentiated by sequential treatment with dex and IBMX displayed insulin sensitivity equivalent to DIM adipocytes, but had lower sensitivity to ISO-stimulated lipolysis and reduced triglyceride content. The nondifferentiating IBMX–then-dex treatment produced transient expression of adipogenic transcriptional regulatory factors C/EBPβ and C/EBPδ, and little induction of terminal differentiation factors C/EBPα and PPARγ. Moreover, the adipogenesis inhibitor preadipocyte factor-1 (Pref-1) was repressed by DIM or by dex-then-IBMX, but not by IBMX-then-dex treatment. We conclude that glucocorticoids drive preadipocytes to a novel intermediate cellular state, the dex-primed preadipocyte, during adipogenesis in cell culture, and that Pref-1 repression may be a cell fate determinant in preadipocytes.
Natural History of Heterophylly in Nymphaea odorata ssp. tuberosa (Nymphaeaceae)

Abstract Nymphaea odorata (American white water lily) is an aquatic plant that displays pronounced heterophylly, the appearance of different leaf forms on a single plant. Water lilies produce leaves that either float or are held above the water's surface. In this paper, we describe the natural history of water lily leaf forms and examine some of the factors that stimulate heterophylly. Over the course of a growing season, the predominant leaf form switches from surface leaves in the early season to aerial leaves in the midseason and then back to surface leaves at season's end. While many factors are known to contribute to heterophylly, our results suggest that changes in the light environment may be the controlling factor in this system.
Genetic Variation and Cultural Evolution1

The breakdown of isolation between groups is theoretically expected to increase the amount of variation within groups. One measure of the in-group variation is the frequency of heterozygosity; this should increase in accordance with the evolution of culture. Concurrently, the variation between groups should diminish. A survey of mean AB, MN, and Cc heterozygosity is undertaken on 252 ethnic groups. Each is classified by level of socio-cultural integration: band, tribe, chiefdom, and state. The geographical distribution of the variables is mapped. Individual ethnic groups are organized into thirteen regions (heterographic areas) which provide reasonably independent tests of the hypothesis in question. Mean blood group heterozygosity for the three loci investigated is 32.47%±0.59 among states as compared to 24.86%±0.49 among primitive societies. The difference (7.61%) is highly significant. Furthermore, in-group heterozygosity increases with each stage of social evolution. The variance between groups diminishes consecutively. It is concluded that the distribution of heterozygosity is strongly dependent upon cultural evolution. Primitive societies are genetically more homogeneous. Empiric evidence supports the Law of Biocultural Evolution. Multiple factor traits would be expected to show an analogous pattern. In contrast to man in general, human paleontologists should find primitive societies to provide closer models of the in-group and between-group variance of fossil hominids. The role of biocultural evolution toward maintaining and increasing human variation is discussed.
Habitat preference of mosasaurs indicated by rare earth element (REE) content of fossils from the Upper Cretaceous marine deposits of Alabama, New Jersey, and South Dakota (USA)

Knowledge of habitat segregation of mosasaurs has been based on lithology and faunal assemblages associated with fossil remains of mosasaurs and stable isotopes (δ13C). These approaches have sometimes provided equivocal or insufficient information and, therefore, the preference of habitat by different mosasaur taxa is still suboptimally constrained. The present study is focused on the analysis of rare earth element (REE) ratios of mosasaur fossils from the Upper Cretaceous formations of western Alabama, USA. Results of the REE analysis are used to infer the relative paleobathymetry associated with the mosasaur specimens and then to determine if certain taxonomic groups showed a preference for a particular water depth. Comparisons are then made with mosasaur specimens reported in the literature from other regions of North America from different depositional environments. Results indicate that Mosasaurus, Platecarpus and Plioplatecarpus may have preferred more restricted habitats based on water depth whereas Tylosaurus and Clidastes favoured a wider range of environments. Results also suggest that Plioplatecarpus lived in a shallower environment than its Platecarpus predecessor. Although the results of this study are encouraging, caution must be exercised before drawing any final conclusions due to the small sample size of most of the taxa analysed.
Vacuum Selection on the String Landscape

I examine some nonanthropic approaches to the string landscape. These approaches are based on finding the initial conditions of the universe using the wave function of the multiverse to select the most probable vacuum out of this landscape. All approaches tackled so far seem to have their own problems and there is no clear-cut alternative to anthropic reasoning. I suggest that finding the initial conditions may be irrelevant since all possible vacua on the landscape are possible initial state conditions and eternal inflation could generate all the other vacua. We are now left to reason out why we are observing the small value of the cosmological constant. I address this issue in the context of noncritical string theory in which all values of the cosmological constant on the landscape are departures from the critical equilibrium state.
Predicting disulfide bond connectivity in proteins by correlated mutations analysis

Motivation: Prediction of disulfide bond connectivity facilitates structural and functional annotation of proteins. Previous studies suggest that cysteines of a disulfide bond mutate in a correlated manner. Results: We developed a method that analyzes correlated mutation patterns in multiple sequence alignments in order to predict disulfide bond connectivity. Proteins with known experimental structures and varying numbers of disulfide bonds, and that spanned various evolutionary distances, were aligned. We observed frequent variation of disulfide bond connectivity within members of the same protein families, and it was also observed that in 99% of the cases, cysteine pairs forming non-conserved disulfide bonds mutated in concert. Our data support the notion that substitution of a cysteine in a disulfide bond prompts the substitution of its cysteine partner and that oxidized cysteines appear in pairs. The method we developed predicts disulfide bond connectivity patterns with accuracies of 73, 69 and 61% for proteins with two, three and four disulfide bonds, respectively. Contact: rrubinst@aecom.yu.edu, andras@fiserlab.org
Geographical space, social space, and the realm of the department store

Over the past decade a number of scholars have examined the rise of the mass production and distribution of goods, and the concurrent emergence of a nineteenth- and twentieth-century consumer society or ‘culture of consumption’. This body of work has featured the department store prominently in several roles: as a venue for the distribution of consumer goods; as a material fantasyland in which women were encouraged to play out their dreams of conspicuous consumption; and as a place of white-collar employment for working-class clerks. Whatever their focus, these accounts generally view all department stores as homogeneous middle-class institutions, located in a similarly consistent ‘downtown’ in any (and all) large American and European cities. There are serious flaws in such a portrayal. Very real distinctions between department stores in a given city and the social implications of these differences in terms of social status and class are not addressed. Further, the contribution of the built environment and urban topography to the shaping of these status and class distinctions and, ultimately, women's shopping experience, is likewise overlooked. This article examines a set of surveys and marketing reports prepared in 1932 for the Higbee Company of Cleveland, Ohio, in order to situate more precisely one department store within its urban context. These sources document the relationship of the Higbee Company to the city's other department stores and in so doing reveal some of the ways in which stratification between and among classes was interpreted in terms of geographical and social space. Examination of the hierarchy of stores that existed in what was at the time the nation's sixth largest city provides a corrective to the image of the department store as a homogeneous democratic phenomenon, and thus provides an invaluable basis for a reinterpretation of the department store as an urban institution in early twentieth- century America.
Dysprosium as a nonabsorbable fecal marker in studies of zinc homeostasis

Background: Dysprosium is a nonabsorbable rare earth element that has had successful application as a marker for fecal excretion of unabsorbed zinc. Objective: Our goals were 1) to evaluate the efficacy of administering dysprosium with all meals over several days as a method of determining the completeness of fecal collections, 2) to determine the similarity of gastrointestinal transit kinetics and excretion patterns of dysprosium and zinc tracer administered simultaneously over several days, and 3) to evaluate alternative methods of using the data for fecal excretion of orally administered zinc tracer and dysprosium to measure the fractional absorption of zinc. Design: 7 0 Zn and dysprosium were administered orally with all meals for 5 consecutive days to 7 healthy, free-living adults consuming a constant diet based on habitual intake. Additional tracers, 6 7 Zn and 6 8 Zn, were administered intravenously. Urine and fecal samples were collected during tracer administration and for 8 d after the last dose. Isotope ratios were measured in urine and feces, and total zinc and dysprosium were measured in fecal samples. Results: The mean recovery of dysprosium was 101.3 ′ 2.4%. The zinc oral tracer and dysprosium had similar fecal excretory patterns; the correlation coefficient for 7 0 Zn and dysprosium in fecal samples exceeded 0.99 (P 0.95) with those from the fecal monitoring and dual-isotope-tracer ratio methods. Conclusion: Administration of dysprosium is a useful means of determining the completeness of fecal collections and of measuring zinc absorption.