cssi/SciSciGPT-SciSciNet huggingface dataset:
Job Satisfaction Among the Expatriates in the UAE

The aim of the present study was to identify the specific factors associated with Job Satisfaction among the expatriates in the UAE. For this purpose employees at a leading global remittance and foreign exchange organization having partners across the world, representing over 40 nationalities and having over 7000 employees were chosen. The study focuses on revealing the influence of various demographic characteristics that these employees exhibited, which affect their satisfaction level. The questionnaires were distributed among 1202 employees (972 males and 230 females) working in the 4 regions of the UAE. The Factor Analysis (KMO Test) was done to identify the critical factors associated with job satisfaction vis-a-vis their Tenure, Age, Gender and Nationality. A total of 14 factors explained 56.273 % of the total variance. Overall the employees were moderately satisfied with the jobs but more satisfied with the following aspects of their current work situation: Future prospects, Team Work, Work Environment and Supervisor Behaviour and Training Programmes (being the Top 5 Satisfiers) and least satisfied with: Incentives, Social Recognition Programmes and Compensation (being the bottom 3 i.e. dissatisfiers). The data also revealed the influence of the demographic factors chosen for the study on the over-all impact on job-satisfaction. The analysis revealed that a total of 14 factors were important for the males whereas the responses from females indicated that a total of 20 factors were important for females. The dominant factors: Customer satisfaction, Ethics, Events, etc. came out to be as important factors for females over and above the 14 factors which were important for males.
Point of No Return From Water Loss in Coptotermes formosanus (Isoptera: Rhinotermitidae).

Describing desiccation stages based on the physical appearance of termites has not been evaluated previously. Formosan subterranean termites were studied to determine the rate of water loss, singly and in groups, in the laboratory. The stages of water loss are described based on changes in physical appearance and percent total body water loss evaluated at 2- to 8-h time intervals up to 32 h. Workers in groups lost water slower than individual worker trials. Weight loss was linear over time for worker groups and individuals, as was individual soldier only trials. Water loss in individual workers was significantly faster than in soldiers. Three physical stages of desiccation are described for living workers: (I) curling of antennae, (II) on back but with assistance able to right themselves and walk, and (III) unable to get off back; and two stages for living soldiers (II and III). Recovery was determined from termites in a second trial by transferring stage I, II, and III individuals from open, dry Petri dishes to those with moist filter paper at 4, 6, 10, 12, 14, 16, 24, 26 and 28 h. After 12 h on moist filter paper, stage I workers had a 83% recovery rate, stage II had a 33%, and stage III had a 7% recovery. Soldiers had a 56% recovery at stage II and was similar to the recovery of workers at stage III. Most termites that reached stage III were destined to die.
Growth and survival of Yersinia enterocolitica at acidic pH

Abstract The ability of three strains of Yersinia enterocolitica to survive and grow in tryptic soy broth (TSB) at pH 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0 was determined. In addition, experiments were done to assess survival of Y. enterocolitica in mayonnaise, spoonable salad dressing, and tartar sauce. Two of the strains were able to grow in TSB at pH 4.5 and above when incubated at 25°C. Cell concentrations of all strains decreased at lower pH values at this temperature. No growth of Yersinia was observed when TSB was incubated at 5°C for any pH tested, although survival was prolonged. Viable cells were not recovered from artificially contaminated tartar sauce (pH 3.2) or spoonable salad dressing (pH 3.4) at any time. Cells survived for at least 48 h in artificially contaminated mayonnaise (pH 3.8) held at 5°C. No viable cells were recovered after 24 h from mayonnaise held at 21°C.
ABSENCE OF APPARENT HORIZONS IN TRANSLATIONALLY-INVARIANT EINSTEIN–MAXWELL SPACETIMES

We show that (3+1) Einstein–Maxwell spacetimes admitting a global, spacelike, one-parameter Lie group of isometries of translational type cannot contain apparent horizons. The only assumption made is that of the existence of a global spacelike Killing vector field with infinite open orbits; the four-dimensional spacetime metric is otherwise completely arbitrary. We discuss the implications of this result for the hoop and cosmic censorship conjectures.
Foliar uptake and translocation of rubidium in bean plants as affected by root absorbed growth regulators

The absorption and subsequent transport of foliar applied Rb86 labeled Rb Cl (10 mM) was studied on bean plants (Phaseolus vulgaris, L. cv. Black Seeded Blue Lake) exposed to physiologically tolerable levels of certain plant growth substances in the solution culture root media. Gibberellin A3 (10-5 M) increased Rb uptake but did not affect total translocation from the treated leaf. Translocation was directed to the upper vegetative parts and markedly reduced to the roots. Foliar influx of Rb and transport to the roots were greatly enhanced by 1-naphthaleneacetic acid (10-6 M) but mobilization of Rb into the leaves and upper stem was reduced. 2-Chloroethyltrimethylammonium chloride (10-3 M) and N,N-dimethylaminosuccinamic acid (3×10-4 M) decreased the mobility of Rb to the upper stem, increased it to the roots, and had no effect on initial uptake. Rb absorption was depressed by 2,4-dichlorobenzyltributylphosphonium chloride (10-5 M) with no effect on subsequent translocation. Both uptake and mobility were strikingly inhibited by N6-benzyladenine (10-6 M).
Rational design of reinforced rubber

Filled elastomer systems have been studied extensively over the past several decades, especially in the application to tire performance. During this time, many attempts have been made to explain reinforcement of an elastomer when fillers are added. These reinforced properties include enhanced strength, modulus, abrasion resistance, and dynamic mechanical properties. Several approaches have been used to separate the contributing influences and to explain how they work. The majority of these approaches look at the structure and property relationships of the fillers and rubbers independently and as a synergistic combination. These approaches have evolved into the following major areas: filler structure, hydrodynamic reinforcement, and interactions involving fillers and elastomers. This paper will review the major works in each of these areas and attempt to offer an overall view of reinforcement of elastomers. Special attention will be paid to the relationships between filler structure and how it may be used to predict reinforcement properties. The general topics that will be covered included filler structure and characterization, rubber and filler interactions, mechanical reinforcement/hydrodynamic effect, and a fractal approach to explaining reinforcement.
The Navy's new standard digital signal processor, the AN/UYS-2

Current Navy signal processing requirements range from tens of millions to hundreds of millions of multiply-add operations per second. It is expected that these requirements will increase tenfold within the next ten years. To accommodate these expanding requirements, the Navy is building the Signal Processor (AN/UYS-2). The AN/UYS-2 design is driven by the fact that it is the Navy standard signal processor. Being a stantard, it must satisfy more requirements than just high throughput. It must be programmable, modular, expandable, flexible supportable, reliable and provide this capability for the next 20 years to support existing and future users. In order to make it programmable (and therefore reduce the total life cycle ownership cost), the AN/UYS-2 utilizes a Navy developed signal processing graph language methodology called PGM. The implementation of PGM on AN/UYS-2, provides the AN/UYS-2 user with a convenient and cost effective way of specifying the signal proccessing algorithms to be executed for a given application. The AN/UYS-2 desgin approach is to implement PGM and to develop a modular, multiprocessor that could meet a wide range of air, sea, and shore signal processing applications. In order to meet this requirement, a hybrid control-flow/data-flow architecture was chosen to enable evolutionary technology infusion. VLSI component technology is required to implement the primary processing engine in the architecture. The AN/UYS-2 architecture consists of a variable combination of multiple types of Functional Elements (FEs), a data transfer network, a control bus, and a built-in-test (BIT) control bus. This paper provides a review of AN/UYS-2 basic design and growth potential.
Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Abstract Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, ( Dipp L)ZnEt ( 3 , Dipp L = [(2,6- i PrC 6 H 3 )NC(CH 3 )] 2 CH − ), a product assigned as the zinc-phosphide ( Dipp L)ZnPHPh ( 6 ) was observed but could not be isolated as a pure compound. A new, less bulky β -diketiminate complex ( Tol L)ZnEt ( 2 , Tol L = [(p-CH 3 C 6 H 4 )NC(CH 3 )] 2 CH − ) was reacted with primary phosphines to give a precipitate and the bis( β -diketiminate)zinc complex ( Tol L) 2 Zn ( 5 ), an apparent product of comproportionation. ( Mes AI)ZnEt ( 1 , Mes AI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.
Mechanisms of VF maintenance: Wandering wavelets, mother rotors, or foci

Ventricular fibrillation (VF), despite its declining incidence as a cause of sudden cardiac death, is still a major health problem. The underlying mechanisms for the maintenance of VF are still disputed. Studies suggest that VF is unlikely one static mechanism but rather a dynamic process of electrical derangement that changes with duration. The 2 principal proposed mechanisms of VF are multiple wavelets and mother rotors. Most studies of these proposed mechanisms for VF maintenance have been during the first minute of VF. However, the time to external defibrillation in the community and pre-hospital settings, where the majority of sudden cardiac death occurs, ranges from 4 to 10 min and the time to defibrillation seems crucial because the odds of survival worsen with delay. Recent studies during the first 10 min of VF suggest that Purkinje fibers are important in maintaining VF after the first 1 to 2 min, either as a part of a reentrant circuit or as a source of focal activations.
Does Comprehensive Emergency Management Work? A Longitudinal Study in The Commonwealth of The Bahamas

Disaster risk cannot be wholly eliminated and communities will continue to be affected by hazards. While governments, organizations and individuals work to limit exposure and reduce susceptibility to the negative social, economic, and environmental impacts of disasters, effective emergency response capabilities must also be developed and exercised, in order to reduce losses, better cope with impacts that do occur, and facilitate recovery. In 2002, the nation of The Bahamas established a comprehensive emergency management (CEM) system intended to improve disaster response capabilities. This paper describes the application of Quarantelli's methodology (1997) in evaluating response operations associated with six hurricanes that affected The Bahamas from 1992 to 2005. The research presented here is part of a 9 year longitudinal study begun in 2001 and designed to examine the influence of CEM on emergency response in an island nation. Results indicated that the implementation of a CEM system improved disaster response in several key areas, providing evidence that CEM is an effective strategy for an archipelagic nation.
Cu-Ni Nanocatalysts in Mesoporous MCM-41 and TiO2 to Produce Hydrogen for Fuel Cells via Steam Reforming Reactions

We have synthesized mesoporous SiO 2 (MCM-41) and TiO 2 encapsulated bimetallic Cu- Ni nanocatalysts using an optimized one-pot hydrothermal procedure. The catalysts were characterized using N 2 adsorption-desorption isotherms (BET), X-ray diffraction (XRD), thermo- gravimetric and differential calorimetric analysis (TGA-DSC) and high-resolution transmission electron microscopy (HRTEM) techniques. Results show that bimetallic Cu-Ni/MCM-41catalysts possessed significantly high surface area in the range of 634-1000 m 2 /g compared to Cu-Ni/TiO 2 which showed a surface area in the range 250-350 m 2 /g depending on the total metal loading (5-10 wt%). The small angle XRD studies confirmed a long range ordered structure in the Cu-Ni/MCM- 41 catalysts. Wide angle XRD studies affirmed the presence of the catalytically active anatase phase in the crystalline Cu-Ni/TiO 2 bimetallic system. The results from HRTEM studies were consistent with the mesoporosity of both supports. These catalysts are tested for methanol conversion and H2/CO selectivity via steam reforming of methanol (SRM) reactions in a down flow fixed bed reactor. Our investigations revealed a distinct contrast in the performance of both supports. While Cu is mainly responsible for the reforming activity in MCM-41, Ni bolstered the methanol conversion in TiO 2 supported catalysts. Bimetallic 3.33%Cu6.67%Ni/TiO 2 catalyst showed an impressive 99% H 2 selectivity at as low as 150 o C and a maximum conversion of 92% at 250 °C but 3.33%Cu6.67%Ni/MCM-41 catalyst did not show any H 2 selectivity at 150 o C and only ~12% conversion at 250 o C. The effect of each support and relative metal loadings on the activity and selectivity of the SRM reaction products at different temperatures is discussed.
Formotion of serine and glyceric acid by the glycolate pathway

Abstract Distribution of C 14 in the C 3 compounds, phosphoglycerate, glycerate, alanine, and serine from five different species of plants was determined after 20 sec. of photosynthesis with C 14 O 2 . In each experiment phosphoglycerate, glycerate, and alanine were predominately carboxyl labeled, but serine was uniformly labeled. Thus, serine biosynthesis must proceed by a different route than that for the other C 3 compounds. Since glycerate was labeled less in the carboxyl carbon than phosphoglycerate, part of the glycerate may have been synthesized from a precursor other than carboxyl-labeled phosphoglycerate. When glycolate-2-C 14 was fed to the same plants, serine-2,3-C 14 and glycerate-2,3-C 14 were major products. When serine-3-C 14 was fed, glycerate-3-C 14 was formed. The C 14 labeling was consistent with a glycolate pathway which started with phosphoglycolate and glycolate and led to the synthesis of glycine, then serine, and finally glycerate. This sequence was substantiated by studies on the time and rate of labeling of these products during glycolate-2-C 14 metabolism. The significance of the glycolate pathway was indicated by the high percentage of fixed C 14 which was found in the products of the pathway after brief periods of photosynthesis with C 14 O 2 . A diurnal variation was observed for the ratio of C 14 photosynthetically incorporated into serine compared to glycine.
Characterizing the dependence of pure-tone frequency difference limens on frequency, duration, and level

This study examined the relationship between the difference limen for frequency (DLF) of pure tones and three commonly explored stimulus parameters of frequency, duration, and sensation level. Data from 12 published studies of pure-tone frequency discrimination (a total of 583 DLF measurements across 77 normal-hearing listeners) were analyzed using hierarchical (or “mixed-effects”) generalized linear models. Model parameters were estimated using two approaches (Bayesian and maximum likelihood). A model in which log-transformed DLFs were predicted using a sum of power-law functions plus a random subject- or group-specific term was found to explain a substantial proportion of the variability in the psychophysical data. The results confirmed earlier findings of an inverse-square-root relationship between log-transformed DLFs and duration, and of an inverse relationship between log(DLF) and sensation level. However, they did not confirm earlier suggestions that log(DLF) increases approximately linearly with the square-root of frequency; instead, the relationship between frequency and log(DLF) was best fitted using a power function of frequency with an exponent of about 0.8. These results, and the comprehensive quantitative analysis of pure-tone frequency discrimination on which they are based, provide a new reference for the quantitative evaluation of models of frequency (or pitch) discrimination.
Regime shifts in ecological systems can occur with no warning

Predicting regime shifts - drastic changes in dynamic behaviour - is a key challenge in ecology and other fields. Here we show that the class of ecological systems that will exhibit leading indicators of regime shifts is limited, and that there is a set of ecological models and, therefore, also likely to be a class of natural systems for which there will be no forewarning of a regime change. We first describe how nonlinearities in combination with environmental variability lead to model descriptions that will not have smooth potentials, concluding that many ecological systems are described by systems without smooth potentials and thus will not show typical leading indicators of regime shifts. We then illustrate the impact of these general arguments by numerically examining the dynamics of several model ecological systems under slowly changing conditions. Our results offer a cautionary note about the generality of forecasting sudden changes in ecosystems.
Rivals Search for Buried Treasure: Competition and Duplication in R&D ∗

We model an R&D race in which each fi rm decides in each period between two research projects, only one of which has positive success probability and it is not known which. There is symmetric information and hence scope for strategic search. If the prize is shared when discovery is simultaneous there is too much duplication of projects. If neither is rewarded in this event then equilibrium is efficient unless projects have asymmetric costs, in which case there is a bias toward the high-cost project, or asymmetric success probabilities, in which case too little duplication is possible. If one firm is informed, it may choose the wrong project to put the other off the scent.
Stone dropping by Conomyrma bicolor (Hymenoptera: Formicidae): A new technique of interference competition

1. The dolichoderine ant Conomyrma bicolor interferes with the activity of other desert ants when their nest entrances are in close proximity. C. bicolor workers surround these nests, pick up small stones and other objects with their mandibles, and drop them down the nest entrances. 2. Interactions of C. bicolor with three species of Myrmecocystus (M. mexicanus, M. mimicus, and M. depilis) were investigated. ‘Stone dropping’ and associated behaviors prevent the Myrmecocystus colonies from foraging. Periodic checks throughout the summer revealed a consistently adverse effect on these Myrmecocystus species. 3. Considerable overlap in food resources, activity times, as well as space among C. bicolor and the Myrmecocystus species suggest that ‘stone dropping’ is a technique of interference competition. 4. We were not able to completely analyze the mechanism which keeps the victimized colonies from foraging. However, we report circumstantial evidence supporting the hypothesis that the stones function as a mechanical signal.
Synchronic Vs. Diachronic Emergence: A Reappraisal

In this paper, I put forward a benchmark account of emergence in terms of non-explainability and explicate the relationship that exists between its synchronic and diachronic declinations. I develop an argument whose conclusion is that emergence is essentially a “two-faceted” notion, i.e. it always encapsulates both synchronic and diachronic dimensions. I then compare this account with alternative recent accounts of (diachronic) emergence that define the concept through the notion of unpredictability or topological non-equivalence.
To Protect and to Serve Alliances And Foreign Policy Portfolios

The consequences of alliance formation for other foreign policies of a state, including defense spending and the initiation of militarized disputes, are examined using a theory of foreign policy that is based on several assumptions. First, states pursue two goods-change (defending those aspects of the status quo that one likes) and maintenance (altering those aspects of the status quo that one dislikes)-through their foreign policies. Second, states select a portfolio of policies designed to produce the most preferred mix of the two goods. Third, all foreign policy behavior, including alliance involvement, requires resources. Fourth, states are rational in their allocation of resources. Together, these imply that an observed alliance must have been the most efficient mechanism available for acquiring the most desired and achievable foreign policy portfolio and have implications for the observation of foreign policy substitutability. The empirical implications of this implication are tested, and results su...
The Ambiguous and Underappreciated Role of Middle Managers in Healthcare Organizations

Balancing strategic awareness with operating experience has become the new mantra for successful high-impact middle managers. Recently, however, the value of middle managers has come under attack. ...
Fatigue-Induced ACL Injury Risk Stems from a Degradation in Central Control

ABSTRACTPurpose:Fatigue contributes directly to anterior cruciate ligament (ACL) injury via promotion of high risk biomechanics. The potential for central fatigue to dominate this process, however, remains unclear. With centrally mediated movement behaviors being trainable, establishing this link se
The effect of solvent short range order on the solvent sensitivity of merocy anine dyes

Abstract A theory of solvent sensitivity is presented which uses the Kirkwood-Frohlich theory of polar liquids to describe short range order in the solvent. This yields a consistent description of hydrogen bonding and non-hydrogen bonding solvents.
Controlled fluorination of clays

Abstract The fluorination of clays by a mild fluorinating reagent, HPF6 was investigated using a sample of bentonite. The reaction resulted in the fluorination at the aluminum sites to form octahedral aluminum oxyfluoride species. This led to considerable modification of the surface characteristics such as surface area, porosity and particle size of nano-clay particles. The fluorinated clay was characterized by X-ray powder diffraction, XPS, SEM, EDS, infrared spectroscopy and solid-state NMR.
A deglitching circuit for the AA50 D/A converter

Switching transients or “glitches” are frequently encountered in signal processing applications involving digital-to-analog (D/A) conversion. A low-cost “deglitching” circuit is described and implemented for the Digital Equipment Corporation AA50 D/A converter option on the PDP-8/e minicomputer. Switching transients were eliminated using a noninverting, unity-gain sample-and-hold circuit (employing Datei System’s SHM-IC-1). Switching transients were reduced to below-noise levels across a wide range of output levels and sampling rates.
The history of parathyroid surgery, 1850-1996: the Excelsior Surgical Society 1998 Edward D Churchill Lecture.

I am honored to deliver the 1998 Excelsior Surgical Society/Edward D Churchill Lecture. This society was the product of military surgery during World War II in the North African and Mediterranean theaters of operation. In periods between their stressful work, surgeons in the theater were provided opportunities for exchanging ideas and promoting social graces. The second auxiliary surgical teams and other surgical officers developed new friendships and renewed old acquaintances. It was only natural that thoughts toward perpetuation of these friendships would develop after the war. The initial meeting of this society was held in October 1946 in Boston, MA. In May 1951, its name was officially changed to the Excelsior Surgical Society. Frank Simeone has reminded us that societies, clubs, and publications are the hallmark of physicians and surgeons. American medical personnel actively participated in conferences held in the Institute of Health at the University of Rome, which were later published as the Proceedings of the Conference of Army Surgeons, Central Mediterranean Forces. Other societies developed, ie, The Constantian Society, the Biserte County Medical Society of Tunisia, and the North Caserte Medical Society (Italy). The Excelsior Hotels in Rome and Florence were frequent sites for these interludes, so the club was named after the Excelsior Hotel in Rome (Fig. 1). This society later established a Churchill Lecture. The initial lecture was given by Alfred Blalock, of Johns Hopkins. The first Churchill Lecture under the auspices of the American College of Surgeons was delivered by W Dean Warren, of Emory University (Fig. 2). The Excelsior Society was founded to honor Colonel Edward Delos Churchill, who would become the one and only honorary member (Fig. 3). Early in his career, Dr Churchill distinguished himself as a pioneer in thoracic surgery. He performed and reported the first pericardiectomy in America for constrictive pericarditis, clarified the physiology and surgical anatomy of the lung, developed a rational approach to the treatment of pulmonary tuberculosis, bronchiectasis, adenoma and carcinoma of the lung, and surgery of the esophagus. Dr Churchill succeeded Edward P Richardson as the John Homans Professor of Surgery at the Harvard Medical School, a position he held until 1962. Churchill, a surgeon’s surgeon, deplored the fragmentation of surgery, believed that young surgeons should become well grounded in the principles of surgery, and advised his residents to spend at least 1 year with a master in the basic sciences during residency. Edward Churchill was indeed a surgical biologist.
Influence of head position and proprioceptive cues on short latency postural reflexes evoked by galvanic stimulation of the human labyrinth.

Abstract This study described the effects of low level (75–250 μA) galvanic stimulation of the labyrinths of the human posture control system. Experiments demonstrated a transient EMG response in gastrocnemius-soleus (GS) muscle with a latency of 100 msec after initiation of galvanic current pulses of 75–250 μA and 50–150 msec duration. These transient EMG responses were modulated by position of the head. With the head turned 90° to one side so that the positive electrode faced posterior resulted in excitation of GS muscles. Turning the head 90° to the other side so that the positive electrode faced anterior resulted in inhibition of GS muscles. The transient EMG response was absent if the head were in its normal forward facing position. A 2 df platform enabled the ankle joints of subjects to be maintained at a fixed angle during sway; thus making vestibular cues critical during control of postural sway. With vestibular cues critical, the transient EMG response caused marked swaying and compensatory responses correlated with galvanic stimulus. Dynamics of these postural responses were tested using both currents of 150 msec duration (to gain an approximate measure of the impulse response of the system) and of 5 sec duration (to measure the step response of the system). A simplified third order model of the results showed that dynamic characteristics of body sway to galvanic stimulation resembled those induced by motion disturbances. The initial postural response to galvanic stimulation was uneffected by the availability of cues from the feet and lower legs, although later components were strongly effected.
Effect of digitalis on the clotting of the blood in normal subjects and in patients with congestive heart failure.

Two groups of subjects were studied in order to evaluate the effect of digitalis on the coagulation of blood. One consisted of hospital patients in congestive heart failure, the other of normal interns. Control determinations were made of clotting and prothrombin times. Various preparations of digitalis were then administered in therapeutic doses. During administration, serial determinations were made of clotting and prothrombin times. The results were tabulated and the effect of digitalis appraised.
Two-dimensional biochemical imaging sensor for spatially resolved glutamate monitoring

A two-dimensional biochemical sensor has been developed for spatially resolved imaging and sensing with 0.2 μM glutamate sensitivity and fast response. The glutamate sensor was made by covalently immobilizing glutamate dehydrogenase onto flat silica plates. The two-dimensional sensor has the advantage of capturing simultaneous measurements at multiple points and may thus allow better understanding of many biological and chemical processes through spatially resolved sensing and imaging.
Two-photon absorption in the vicinity of the exciton absorption in CdS☆

Abstract The two-photon absorption spectrum of CdS in the wavelength region of the free and bound exciton lines has been measured using a pulsed dye laser and a differential transmittance technique. An intense absorption band is observed which is possibly due to the interference of the contributions of different intermediate states to the interband two-photon absorption. No absorption is observed which can be attributed to the formation of free excitonic molecules.
Continuous measurement of nontidal variations of gravity

Records from seven superconducting gravimeters operated at five different locations in California and one in Boulder, CO, are examined after removal of tides and the gravitational attraction of the atmosphere. Fluctuations over periods between a few days and several months were observed at all sites with peak amplitudes of order 10 microgal. By contrast, a 640-day record obtained with one of the instruments in Germany showed peak fluctuations of only 2 microgal. In most of the records the causes of these aperiodic variations were not determined so that they serve to set limits on the vertical motion or displacement of mass at the respective locations. However, at The Geysers geothermal field, much of the gravity variation is correlated with seismic activity, reinjection rate, and rainfall. Measurements of this type were not possible prior to the development of the superconducting device. Consequently, these results provide the first evidence for the existence of gravity variations on the time scale and of the magnitude described here. Vertical crustal motion, motion related to seismic events, and hydrological phenomena can lead to variations on this scale. Unambiguous identification of causal relationships will require either special circumstances such as found at The Geysers or operation of the instruments in pairs.
Income inequality and population health: Correlation and causality ☆

A large literature now exists on the cross-national correlation between income inequality and population health, but existing studies suffer from sparse data, poor operationalization of income inequality, and the use of low-power statistical models. This paper sets out to estimate the ecological correlation between income inequality and indicators of population health in a very broad panel of countries, to demonstrate that this relationship is largely non-artifactual, and to test whether this relationship might be causal. Gini coefficients of national income inequality in 1970 and 1995 are correlated with life expectancy, infant mortality rates, and murder rates, controlling for national income per capita. In cross-sectional analyses, inequality is significantly correlated with life expectancy, infant mortality, and (inconsistently) the murder rate. The health correlations are shown to be not primarily due to the "convexity effect" of the non-linear relationship between individual income and individual health, which seems to account for no more than one-third of the relationship between inequality and health, and likely much less. Change in inequality 1970-1995 is significantly related to change in life expectancy and infant mortality, suggesting a causal relationship, but these correlations are not robust with respect to sample or controls. It can be concluded that there is a strong, consistent, statistically significant, non-artifactual correlation between national income inequality and population health, but though there is some evidence that this relationship is causal, the relative stability of income inequality over time in most countries makes causality difficult to test.
Transport properties of polycrystalline type-I Sn clathrates

Thermal conductivity, resistivity, Seebeck coefficient, and Hall measurements on polycrystalline Sn-clathrate compounds with the type-I hydrate crystal structure are reported. Interstitial alkali-metal atoms in these compounds reside inside polyhedral cavities formed by the tetrahedrally bonded Sn network atoms. Localized disorder associated with "rattling" motion of these interstitial atoms contributes to the low thermal conductivity of these semiconducting compounds. The Hall coefficient and resistivity for some compounds exhibit nonmonotonic temperature dependences consistent with a crossover with decreasing temperature from conduction-band to impurity-band conduction. The carrier mobility is found to be low even in the absence of interstitial atoms within the Sn framework, suggesting a large effective mass and/or scattering rate. We discuss the properties in the context of potential thermoelectric applications.
Patterns of family location.

Theoretical propositions from human ecology are used to develop a model that explains the centralization or decentralization of various types of families, such as married couples with children, in the Cleveland, Ohio, Metropolitan Area. The model shows how proximity to the Central Business District affects neighborhoods in terms of three characteristics: Age or period of development, both internal and external housing Space, and Site features such as industrial and recreational activity. These structural characteristics are seen, in turn, as the causes of the location of families in relationship to the center of Cleveland. Of the three characteristics, Space generally plays the most important and Site the least important role in determining the location of types of families. However, the location of most types of families is affected by a variety of interrelation-ships among neighborhood characteristics.
Green's-tensor approach in the theory of the surface or interface vibrational contribution to thermodynamic properties of solids

We present a theory of the surface or interface contribution to vibrational thermodynamic properties of solids. We express the thermodynamic quantities such as the free energy and specific heat in terms of the surface or interface density of vibrational states. We derive a simple analytic expression for this function in terms of a static Green's tensor of the system. We redefine the dynamical Green's tensor compared with some earlier works, requiring that it correspond to a Hermitian differential operator. In order to calculate the free energy, we modify the Debye model to apply it to surface or interface problems. The free energy and specific heat are calculated for the cases of an isotropic solid bounded by a stress-free planar surface and two isotropic solids separated by a flat interface. \textcopyright{} 1996 The American Physical Society.
A robust weighted Kaplan-Meier approach for data with dependent censoring using linear combinations of prognostic covariates

The weighted Kaplan-Meier (WKM) estimator is often used to incorporate prognostic covariates into survival analysis to improve efficiency and correct for potential bias. In this paper, we generalize the WKM estimator to handle a situation with multiple prognostic covariates and potential-dependent censoring through the use of prognostic covariates. We propose to combine multiple prognostic covariates into two risk scores derived from two working proportional hazards models. One model is for the event times. The other model is for the censoring times. These two risk scores are then categorized to define the risk groups needed for the WKM estimator. A method of defining categories based on principal components is proposed. We show that the WKM estimator is robust to misspecification of either one of the two working models. In simulation studies, we show that the robust WKM approach can reduce bias due to dependent censoring and improve efficiency. We apply the robust WKM approach to a prostate cancer data set.
Policies related to combating desertification in the United States of America

Desertification in the United States of America is very complex and difficult to combat on a continuing basis and on a large scale. It can be due to improper agricultural practices, livestock grazing, mining, fire management, recreation practices, deforestation, urbanization, and introduction of exotic species. Thus, national, state, and local policies must deal with a wide range of circumstances and land uses, and they must be comprehensive and dynamic, providing flexibility as issues, knowledge, and needs change. The United States can demonstrate many causations, but also successes, in combating desertification. However, much more work is needed to assure sustainable use of millions of hectares, particularly in the drylands of the western United States. A vigilance on policies and their implementation is required to assure that efforts to combat desertification are effective. Over time, some policies outlive their purpose and require change, but that is not always easy to achieve, and many times it takes a concentrated effort over several years or more to bring about, especially if that policy has its basis in law. Although this process sometimes seems slow, new laws continue to be enacted and policies are adopted that address land uses and the difficult task of combating desertification. Several examples are offered to show the variety of actions taken and processes used in the United States. © 1998 John Wiley & Sons, Ltd.
The effect of limited proteolysis on enzymatic, binding and immunological properties of ligandin.

Abstract The peptide mixture obtained from controlled proteolytic digestion of ligandin with proteinase K or subtilisin retained 40% of glutathione-S-transferase and steroid isomerase activities, immunological reactivity and lower affinity bilirubin binding but binding at the primary site was abolished. When these limited proteolytic digests, which had no intact ligandin as determined by SDS gel electrophoresis, were subjected to Sephadex G-75 column chromatography, 40–50% of the peptide fragments were recovered in fractions where intact ligandin eluted. The results suggest that intact ligandin is not required for enzymatic activities, binding of bilirubin at the secondary site, or immunological reactivity; steroid isomerase and glutathione-S-transferase activities are modulated in a parallel manner and may be mediated by the same region of the protein, and primary and secondary binding sites for bilirubin are distinct and independent, despite nicks introduced by proteolysis in ligandin's subunits, some of the fragments remain associated under non-denaturing conditions and the susceptibility of the two subunits to the proteases is different.
Variation in frequency of hybrids and spatial structure among Ipomopsis (Polemoniaceae) contact sites.

Summary • Rates of hybridization vary among angiosperm taxa. Among-taxon variation in hybridization rate has been used to compare the importance of pre- and post-zygotic reproductive isolating mechanisms. Variation in rates of hybridization within a single-species pair would suggest that local conditions also affect reproductive isolation within a single taxonomic context. • In this study, contact sites of Ipomopsis aggregata–Ipomopsis tenuituba were surveyed for variation in frequency of hybrids, and spatial structure. Floral morphology was used to identify parent species and hybrids in seven contact sites in the western Rocky Mountains, USA. • Contact sites varied widely in elevational range, the degree to which morphological variation was clinal rather than mosaic and the frequency of hybrids. Two sites provided a strong contrast between a clinal, unimodal site and a mosaic, bimodal site. • This natural variation among contact sites of the same species pair provides an opportunity to assess the effect of local ecological conditions and spatial structure of parent populations on reproductive isolation, while controlling for between-taxon variation.
Dose-dependent effects of prostaglandin D2 on hemodynamics, renal function, and blood gas analyses

Dose-response effects of prostaglandin D2 (0.125, 0.25, 0.5, and 0.75 micrograms/kg/min) infused intravenously in pentobarbital-anesthetized dogs were studied with particular reference to renal, pulmonary, and systemic effects. Another group receiving the vehicle alone served as controls. Prostaglandin D2 administration resulted in a significant dose-dependent increase in renal artery flow, urine output, creatinine clearance, plasma renin activity, sodium excretion, potassium excretion, and pulmonary artery pressure. A significant decrease occurred in renal resistance and arterial PO2. There were no appreciable changes in mean arterial pressure, heart rate, hematocrit, platelet count, arterial pH, and PCO2. In the vehicle control group, all other parameters remained relatively stable, except for some increase in the mean arterial pressure, plasma renin activity, and potassium excretion. The results of this study suggest that prostaglandin D2 administered intravenously at levels lower than those required to produce adverse pulmonary and systemic effects will improve the renal blood flow and function.
Method for Increasing the Operating Distance of MEMS LIDAR beyond Brownian Noise Limitation

A LIDAR based on a MEMS tunable VCSEL uses resonance tuning to increase the maximum range ten-fold. A novel demodulator reduces the peak electrical beat frequency from 52GHz to 235MHz for compatibility with standard CMOS.
Conformation-Switching in Adenylate Kinase Revisited with a Path-Ensemble Simulation

Adenylate kinase (ADK), which reversibly converts ATP and AMP to two ADP molecules, has two conformational states, inactive (open) and active (closed); crystal structures of both states were solved in mid 1990s. Numerous studies using experiments as well as computer simulations have aimed to elucidate the relationship between conformational rearrangement and ADK function. However, the detailed mechanism of the switching between the states has not been fully understood. Computationally, sampling the conformation space is the key limitation. We therefore employ the “weighted ensemble” (WE) simulation technique, a parallel, enhanced sampling method for characterizing non-equilibrium and equilibrium processes that would be impractical to observe using brute force simulation. Because it yields an ensemble of transition events, WE provides a unique lens for examining the mechanism (i.e., the time sequence of intermediate states), including possible heterogeneity, of conformational switching in all-atom ADK.
Comparative effects of amphetamine, scopolamine, chlordiazepoxide, and diphenylhydantoin on operant and extinction behavior with brain stimulation and food reward

Abstract The effects of amphetamine, scopolamine, chlordiazepoxide and diphenylhydantoin have been investigated on operant behavior for brain and food reward, and during extinction with both rewards. The aim was to obtain evidence for a possible mode of action of these facilitatory compounds on self-stimulation behavior. The first 3 drugs increased responding for brain reinforcement, but diphenylhydantoin did not when the reward was a shock in the posterior lateral hypothalamus. Only amphetamine produced striking resistance to extinction of self-stimulation behavior. The facilitation of self-stimulation observed with chlordiazepoxide was independent of the rate of self-stimulation; it was rate-dependent with amphetamine and scopolamine. Operant behavior with food reward was facilitated with amphetamine although consumption of food was depressed. Chlordiazepoxide had no effect on operant behavior for food reward but increased food consumption; scopolamine and diphenylhydantoin depressed responding. During extinction with food reward, amphetamine caused long-lasting resistance to extinction; scopolamine had similar but transient effects; chlordiazepoxide had no effect, and diphenylhydantoin decreased resistance to extinction. The significance of these results are discussed in relation to the concept of arousal: the effects of the drugs seem to depend on their adding to or subtracting from the state of behavioral excitation of the animal induced either by self-stimulation or by hunger. It is concluded that the facilitation of moderate self-stimulators by amphetamine and scopolamine was due at least partially to their action on gross behavioral activity, that of chlordiazepoxide was not.
A Comparison of Imaging of Compression Ignition Phenomena of Iso-Octane, Indolene, and Gasoline Fuels in a Single-Cylinder Research Engine

High-speed imaging combined with the optical access provided by a research engine offer the ability to directly image and compare ignition and combustion phenomena of various fuels. Such data provide valuable insight into the physical and chemical mechanisms important in each system. In this study, crank-angle resolved imaging data were used to investigate homogeneous charge compression ignition (HCCI) operation of a single-cylinder four-valve optical engine fueled using gasoline, indolene, and iso-octane. Lean operating limits were the focus of the study with the primary objective of identifying different modes of reaction front initiation and propagation for each fuel. HCCI combustion was initiated and maintained over a range of lean conditions for various fuels, from φ = 0.77 to 0.27. The time-resolved imaging and pressure data show high rates of heat release in HCCI combustion correlate temporally to simultaneous, intense volumetric blue emission. Lower rates of heat release are characteristic of spatially-resolved blue emission. Gasoline supported leaner HCCI operation than indolene. Iso-octane showed a dramatic transition into misfire. Similar regions of preferential ignition were identified for each of the fuels considered using the imaging data.Copyright © 2006 by ASME