cssi/SciSciGPT-SciSciNet huggingface dataset:
Zooplankton Data from High-Frequency Coastal Transects: Enriching the Contributions of Ocean Observing Systems to Ecosystem-Based Management in the Northern California Current11The opinions expressed herein are those of the authors and do not represent official policy of NOAA or the National Marine Fisheries Service.

In the northern California Current, we have employed high-frequency coastal transects (HFCTs, 12 h, cross-shelf transects, repeated at monthly or shorter intervals) to collect data on zooplankton communities and their environment. Nearly 20 years of observations of copepod community structure along the Newport Hydrographic Line has revealed links between climate variability and ecosystem productivity that now underpin ecosystem indicators and fisheries forecasting tools. More recent sampling off northern California has found substantial spatial variability within the region, thus demonstrating the value of networked HFCTs as part of ocean observing system (OOS) in spatially complex coastal ecosystems. Beyond the operational contributions of data and indices to OOS, HFCTs offer important, year-round, and cross-shelf perspectives on productivity, transport, and biophysical interactions to inform model development, and they are a source of collaborative support for the development of advanced sampling technologies.
Coherently Scattering Targets

This chapter contains sections titled: Radar Targets The Jones Matrix The Sinclair Matrix Matrices With Relative Phase FSA-BSA Conventions Relationship Between Jones and Sinclair Matrices Scattering with Circular Wave Components Backscattering Polarization Ratio of the Scattered Wave Change of Polarization Basis: The Scattering Matrix Polarizations for Maximum and Minimum Power The Polarization Fork Nonaligned Coordinate Systems Determination of Scattering Parameters References Problems ]]>
Perfluorinated Polymers, Tetrafluoroethylene–Perfluorodioxole Copolymers

Copolymers of tetrafluoroethylene–perfluorodioxole are perfluorinated amorphous polymers and have unusual combination of properties. These polymers, commonly known as Teflon AF, have high temperature stability, excellent chemical resistance, low surface energy, low water absorption, high limiting oxygen index, solubility at ambient temperature in fluorinated solvents, high transparency, and low refractive index. They are stiffer and have high gas permeability. The glass-transition temperature is sensitive to polymer composition and the structure of the dioxole monomer. These polymers can be processed by various solution processing techniques such as spin coating, dip coating, spraying, or casting. Melt-processing techniques such as extrusion and injection molding are used. They are used in antireflective coatings, low dielectric coatings, pellicles in electronic chips, plastic optical fiber, and gas separation membranes. Keywords: perfluorinated polymers; tetrafluoroethylene–perfluorodioxole copolymers; Teflon AF; perfluorodioxole; amorphous polymer
Activation and Chemisorption of Hydrogen on Aluminum Clusters

We present results from theoretical and experimental investigations of the chemical (H2 activation) and electronic properties (ionization potentials) of aluminum clusters. The chemisorption of H2 on aluminum clusters exhibits a remarkable sensitivity to the number of metal atoms in the cluster. Al6 is the smallest cluster for which chemisorption of H2 is observed experimentally and for which a stable dissociately chemisorbed state for H2 is predicted. For clusters containing more than 6 atoms, the reactivity decreases rapidly with increasing cluster size. For the bare aluminum clusters, theoretical predictions and experimental measurements of ionization thresholds are in good agreement. Using the reactive Al6 cluster as model, we discuss how electronic factors influence H2 dissociative chemisorption on metals. We find that while charge transfer from the cluster to the H2 antibonding orbital is important, the activation barrier is dominated by repulsive interactions between the H2 and the cluster. The charge state of the cluster (anion, neutral or cation) has only a small effect on the activation barrier, which suggests that similar size selectivity might be expected for charged and neutral clusters.
Biogeography and colonization history of plethodontid salamanders from the Interior Highlands of eastern North America

Aim The Interior Highlands (Ouachita Mountains and Ozark Plateau) are major physiographical regions of eastern North America and harbour many endemic species. Despite their close proximity, the Ozarks and Ouachitas have different geological histories and relatively distinct species pools. Few studies have tested the biogeographical origins of this region's fauna, and most researchers have treated the Interior Highlands as a single unit. Here, we inferred the sources and timing of colonization of the Ozarks and the Ouachitas by analysing the biogeography of three genera of plethodontid salamanders (Eurycea, Plethodon and Desmognathus). Location Eastern North America. Methods We constructed a well-sampled, time-calibrated phylogeny for the family Plethodontidae using three mitochondrial and three nuclear genes in beast. Genetic data were primarily taken from GenBank, although we also produced 76 novel sequences. Using lagrange, we reconstructed ancestral areas for North American plethodontids. We compared the frequency and timing of dispersal events between the Ozarks and Ouachitas to other putative sources such as the Eastern Highlands (Appalachian Mountains and associated limestone plateaus). Results We inferred nine dispersal events from the Eastern Highlands to the Interior Highlands, and just two dispersal events between the geographically proximate Ozarks and Ouachitas. Following one dispersal in the Oligocene, other inter-highland dispersal events occurred in the Miocene and Pliocene, including two periods of near-synchronous movements. Main conclusions Given the relatively limited faunal exchange between the Ozarks and Ouachitas, we conclude that either the river valley separating the Ozarks and Ouachitas is a more formidable barrier to plethodontid salamander dispersal than barriers separating the Interior Highlands from the Eastern Highlands, or ecological/community contingencies have limited dispersal within the Interior Highlands. In our study, geographical proximity of upland islands does not correspond with faunal similarity.
Ration density as a factor controlling food intake in ruminants.

Abstract The voluntary food intake of ruminants is probably regulated by a complex mechanism involving a variety of stimuli. It is difficult to predict the voluntary food intake of ruminants with the present understanding of this mechanism. In an effort to relate to intake such factors as ration bulk and ration form ("natural," finely ground, pelleted, i.e.), ration density was studied. Nine rations with densities varying from 0.2 to 0.8g/ml were fed to either cattle or sheep. The equation expressing the relationship between voluntary bulk intake and density of ration was X=73 ρ −1·20 (X=ml/wkg 3/4 /day; ρ =g/ml). This empirical relationship is not an all inclusive prediction of food intake of ruminants, but it may be useful in predicting intake of animals under similar conditions receiving widely varying rations.
Cr isotope fractionation factors for Cr(VI) reduction by a metabolically diverse group of bacteria

Abstract Reduction of Cr(VI) is an important process that determines the geochemical behavior, mobility and bioavailability of Cr in both terrestrial and marine environments. Many metabolically diverse microorganisms possess Cr(VI) reduction capacity. Cr(VI) reduction fractionates Cr isotopes and thus 53Cr/52Cr ratios can be used to monitor Cr(VI) reduction and redox conditions. The magnitude of isotopic fractionation (e) for a variety of microbial reduction mechanisms must be known for accurate interpretation of observed shifts in 53Cr/52Cr ratios. We determined isotopic fractionation factors for Cr(VI) reduction by metal reducers Geobacter sulfurreducens and Shewanella sp. strain NR, a denitrifying soil bacterium Pseudomonas stutzeri DCP-Ps1, and a sulfate reducer Desulfovibrio vulgaris. All bacteria investigated in this study produced significant Cr isotope fractionation. The fractionation (e) for G. sulfurreducens, Shewanella sp. (NR), P. stutzeri DCP-Ps1, and D. vulgaris were −3.03‰ ± 0.12‰, −2.17‰ ± 0.22‰, −3.14‰ ± 0.13‰, and −3.01‰ ± 0.11‰, respectively. Despite differences in microbial strains in this study, the e did not vary significantly except for Shewanella sp. (NR). Our results suggest that strong isotopic fractionation is induced during Cr(VI) reduction under electron donor poor (∼300 μM) conditions.
Intergroup Marriage: An Examination of Opportunity Structures

Though a number of authors have noted the increase in interracial marriages in the United States over the past few decades, few researchers have systematically examined variables that affect the opportunity for intergroup marriage among several different groups: Whites, African Americans, Asians, and Hispanics. In this paper we examine several “opportunity” variables and their relationship to intergroup marriage for couples age 40 or younger: immigration, military service, metropolitan residency, age, region, college attendance, and socioeconomic status. We examine these relationships for African, White, Asian, and Hispanic Americans. Results for both males and females are presented. The analysis is based on data from the 1990 census. The propensity to marry within one's own group dropped slightly for all groups but Asian Americans from 1980 to 1990. White and Black Americans continue to have the highest endogamy rates. Hispanic and Asian Americans have lower rates, and regional variations are highest for them as well. The results suggest that the opportunity variables are important factors affecting rates of intergroup marriage.
“Harpoon” Model for Cell–Cell Adhesion and Recognition of Target Cells by the Natural Killer Cells

Abstract The mechanism of recognition by natural killer (NK) cells is still unknown. A dynamic model is formulated describing recognition or NK-sensitive target cells (TCs) by NK cells of NK-like cells. This model does not assume the presence of the specific NK-receptor(s) on the membrane of NK cells and corresponding specific ligands on the NK-sensitive TCs. We suggest: (1) the expression of various kinds of “non-NK receptors” and corresponding ligands (counter-receptors) on the plasma membrane of the same NK cell and, possibly, of TCs (e.g. LFA-1 and ICAM-1-ICAM3, CD2 and LFA-3; receptors for TNF and corresponding ligand etc.); (2) the presence of multiple disorders in the organization of “extracellular matrix-surface membrane-submembrane cytoskeleton” assembly of the NK-sensitive TCs; (3) non-specific primary linking of NK cell with TCs, which induces a transfer of vesicles or membrane fragments from the NK surface to the target cell surface (and perhaps vice versa). These processes may also permit the transfer of many types of receptor and counter-receptor molecules from the surface of one conjugated cell to another by vesicles or membrane fragments. After transferral through the intercellular cleft, the free receptors and counter-receptors will be localized on both cell surfaces at the contact region between conjugated cells. By this model the NK cell can “harpoon” the TC and enhance the binding forces between cells up to the critical level and then switch on killing mechanisms for the TC. By means of this “harpoon” model of cell recognition, it seems possible to explain the nature of the wide polymorphism of TCs which are sensitive to the effect of NK and NK-like cells. A mathematical model of the NK cell cytotoxic reaction is described. The model describes many nonlinear peculiarities of the cytotoxic process and predicts some new phenomena. We suggest new approaches of manipulation of cell membranes which can transform NK-resistant target cells in NK sensitive cells and vice versa.
Reproductive biology of the female leaf-nosed bat, Macrotus californicus, in Southwestern United States: I. a morphometric analysis of the annual ovarian cycle.

In Macrotus californicus (Phyllostomatidae), normal embryogenesis (March–June) is preceded by a period of delayed development (October – March) characterized by implantation and slow growth of the embryo to the primitive streak stage. The events of the annual reproductive cycle can be correlated with ovarian dynamics. Waves of follicular growth appear to be initiated in January and June. Increased multilaminar follicles resulting from the second wave of recruitment appear from August to October. Vesiculation of these follicles is seen in both ovaries from July to January; however, the single Graafian follicle forms only in the right ovary just prior to ovulation in late October-early November. Left ovarian ovulation can be induced by right ovariectomy. High atresia from July to December may retard embryogenesis by failing to provide an optimal hormone milieu for the conceptus. In addition, luteal cells are small during the initial months of embryonic development. The first wave of follicular growth results in the appearance of an increased percentage of growing follicles in April; resultant enhanced estrogen levels may influence the resumption of normal development, an event which also coincides with luteal cell hypertrophy. It would appear possible, therefore, that delayed development in Macrotus is an expression of luteal cell insufficiency and uterine nutritional incompetence resulting from depressed steroid levels. Termination of delay may be brought about by the action of increased levels of estrogen and/or progesterone on the endometrium, perhaps by influencing the activity of mast cells whose products are known in some species to enhance vascularity which in turn could account for added substances essential to normal fetal growth.
Nobel Laureate Gary S. Becker: Ideas About Facts

In September 1952 The American Economic Review published a note on multi-country trade written by an obscure Princeton undergraduate. Two months later a paper on monetary theory by the same student and one of his Princeton instructors appeared in Economica. Thus was launched the career of one of the most influential social scientists of the second half of the twentieth century, a career that was recognized by the Nobel Prize Committee for Economics in 1992 with its award to Gary S. Becker…
Prior statistical distributions implied by dynamical threshold laws for molecular collisions

Abstract Dynamical threshold laws imply a particular translational energy dependence of the prior distribution function used in surprisal theory. The microcanonical prior distribution is not compatible with collinear and coplanar threshold laws but is compatible with three-dimensional dynamics.
Hexakis[μ2‐4‐(N‐n‐butyl­imino)pentan‐2‐onato]trimagnesium(II)

The title compound, [Mg3(C9H16NO)6], represents a trimeric complex with all Mg atoms having octa­hedral coordination. The central Mg atom occupies a special position on a crystallographic inversion centre and is coordinated by six O atoms [Mg—O = 2.069 (2), 2.083 (2) and 2.072 (2) A], all of which have bridging functions. Each of the peripheral Mg atoms is coordinated by three bridging O atoms [Mg—O = 2.090 (2), 2.086 (2) and 2.095 (2) A] and three terminal N atoms of the butyl­imino groups [Mg—N = 2.206 (2), 2.202 (2) and 2.196 (2) A].
Detection of Intracellular Tumor Necrosis Factor α in Stimulated Fetal Cells

Abstract Background. It is unknown if immature fetal cells produce tumor necrosis factor (TNF) α in the same manner that adult cells do. The aim of this study was to determine the feasibility of early detection of intracellular TNF produced by circulating human monocytes (Mo) and lymphocytes (Ly) using flow cytometry and to compare the stimulation profiles of mature and fetal cells. Material and methods. Fetal umbilical cord blood ( n = 10) and adult volunteer blood ( n = 10) were obtained. In vitro stimulation with endotoxin (LPS) and ionomycin-PMA was performed. Brefeldin A was added to prevent extracellular transport of TNF. Cell type was determined by using CD-14 marker separating monocyte and lymphocyte populations. Anti-human TNF monoclonal antibody was used to detect intracellular TNF by flow cytometry analysis. Results. Thirty to sixty thousand cells were analyzed per sample. Average TNF expression of stimulated fetal Mo was 28.2%, and that of fetal Ly was only 1.1%. Adult stimulated Ly had an average TNF expression of 31.9%, and adult Mo, 29.6% ( P Conclusion. TNF flow cytometry analysis allows assessment of individual cell types and their ability to produce that cytokine. Fetal cells are able to produce TNF when stimulated, but the stimulation profile of Ly differs from that of adult samples. This observation may be of clinical importance in evaluating the response of immature cells to a septic stimulus. Flow cytometry is reliable, reproducible, quick, and easily obtained from a small sample of peripheral blood. Clinical use will be applicable once appropriate controls are developed, as reported in this study.
Fertility options for patients with stages IA2 and IB cervical cancer: presentation of two cases and discussion of technical and ethical issues.

Abstract Background: Ten percent to 15% of women diagnosed with cervical cancer are in their childbearing years. Traditional therapy for stage IA2 and IB lesions, radical hysterectomy, negates future fertility potential. Assisted reproductive technology might offer these women fertility options. Cases: Two cases of young nulliparous women with stage IA2 cervical cancer, who underwent ovarian stimulation and oocyte retrieval followed by radical hysterectomy, were presented to illustrate the technical difficulties of oocyte stimulation and retrieval in the setting of cervical carcinoma. Conclusion: Many issues should be considered when counseling a woman with early-stage cervical cancer about future fertility. These include ethical issues of embryo freezing and gestational surrogacy and practical issues of ovarian preservation and transposition. No current guidelines exist to identify appropriate candidates for assisted reproductive technology in this setting.
Assessment of energy reserves by damselflies engaged in aerial contests for mating territories

Abstract Abstract. Male Calopteryx maculata (Odonata) damselflies engage in prolonged, highly escalated aerial contests for mating territories. A previous study (Marden & Waage 1990, Anim. Behav. , 39, 954-959) found that winners of contests had a higher fat content than losers in 88% of cases, whereas differences in physical variables related to size and flight ability were not related to the outcome of contests. Here that study is extended in order to determine whether contests proceed until one contestant reaches a lower physical limit in fat reserve, or alternatively, whether contestants are able to assess each other's fat reserves and thereby settle contests before physical limits are reached. The physical limitation hypothesis was not supported, as losers showed no reduction in variability of fat content relative to winners. The assessment hypothesis was supported by an increase in the accuracy of the 'fatter wins' rule with increasing contest duration. Winners were fatter in 17 of 25 (68%) short contests (duration 500 s), which suggests a gradual accumulation of information during contests. The assessment hypothesis was supported further by a negative relationship between contest duration and energetic asymmetry between contestants in long contests. Duration of long contests was also positively related to the total fat content of the two contestants, which suggests that the ability of contestants to perceive relative energetic status may vary depending on absolute levels of energy reserves. A model that assumes an asymptotic increase in flight performance with increasing fat content (i.e. Michaelis-Menten or 'saturation' kinetics) is proposed to explain the simultaneous effects of relative and absolute fat content on contest duration, and to examine possible mechanisms that damselflies use to assess each other's energy reserves.
COGNITIVE FUNCTION IN CONGENITAL ADRENAL HYPERPLASIA

Cognition in patients with CAH has not been as well studied as other aspects of psychologic function. Nevertheless, it is possible to make some conclusions and to offer a number of hypotheses for further study (Table 1). First, patients with CAH do not seem to have an overall intellectual advantage as a direct consequence of the disease. The high IQs reported in some groups of patients with CAH are also reported in their siblings and probably reflect sampling bias. Second, it is possible that, on average, patients with salt-wasting CAH have lower overall ability than patients with the simple-virilizing form, but both groups are well within the normal range, and there is considerable variability among both groups. Third, the evidence to date does not confirm that patients with CAH are more likely to have diagnosable learning disabilities when compared with their unaffected relatives, but this issue has not been well studied with the appropriate psychoeducational assessments. It is unlikely that patients with CAH are at substantially increased risk for frank learning disabilities, but they may be likely to have problems in specific areas. Fourth, females with CAH seem to have enhanced spatial ability as a result of exposure to high levels of androgens early in development. The neural substrate of this advantage is unknown but a subject of active research. It is unclear whether when compared with their unaffected siblings, females with CAH are better in other abilities that are typically performed best by males or worse in abilities typically performed best by females. Fifth, it is likely that patients with CAH have other cognitive changes as a consequence of disease characteristics (besides androgens) and of the treatment of the disease. Some evidence suggests that patients with CAH are more likely to have white-matter brain changes produced by the disease and its treatment. This has not been well studied but should be because of the potential clinical implications. It is reasonable to hypothesize that there will be cognitive changes that reflect effects of undertreatment (e.g., ACTH effects on attention) and other changes that reflect effects of overtreatment (e.g., glucocorticoid effects on memory). Some of these effects may be transient, reflecting acute brain changes, whereas others may become chronic as a result of permanent brain changes with repeated exposure. There is need for continuing study of cognition in patients with CAH. Such studies will provide basic information about hormonal effects on cognition and the neural mechanisms that mediate those effects. They will also provide important clinical information to guide psychologic and medical treatment of patients.
Beat Frequency is Reduced but Waveform Shape is Conserved in Chlamydomonas Flagella at High Viscosity

Motivation: Cilia and flagella are thin subcellular organelles that produce fluid movement and cell motility. Coordinated activity of the motor protein dynein causes sliding between adjacent microtubule doublets and subsequent bending of the cilium. Here, the role of mechanical feedback in dynein regulation is investigated by studying the effects of increased viscosity on the flagellar waveform.Methods: Flagellar waveforms of the unicellular green alga Chlamydomonas reinhardtii were measured in media of different viscosities. Genetic mutants missing inner dynein arms (ida1) or outer dynein arms (oda2) were used to investigate the force-dependent contributions of these molecular motors to the flagellar waveform. Media viscosity was increased from 1.5 cP to 4.7 cP using Ficoll 10% w/v. High speed videos (350 fps) of periodically-beating uniflagellate cells were processed in MATLAB to extract waveform parameters sensitive to external viscosity, and to compare mutant cells to wild-type cells.Results: Beat frequency decreased with increasing viscosity in wild-type (59.5±7.0 Hz to 31.7±9.1 Hz) and mutant cells (ida1: 50.4±6.1 Hz to 27.3±11.1 Hz; oda2: 24.9 ±4.0 Hz to 7.2±1.8 Hz). Both wild-type and oda2 cells exhibited greater maximum curvature at the higher viscosity (wild-type: 0.212±0.042 rad/μm to 0.287±0.025 rad/μm; oda2: 0.163±0.033 rad/μm to 0.230±0.014 rad/μm). Curvature differences were smaller in the ida1 mutant (0.266±0.024 rad/μm to 0.288±0.089 rad/μm). Shear rate and bend propagation speed decreased with viscosity, and the amplitude of shear was reduced slightly. Notably the qualitative shape of the waveform and relative differences between wild-type, ida1, and oda2 were maintained at the higher viscosity.Discussion: At higher viscosity, beat frequency decreases to maintain viscous force amplitudes and flagellar waveforms similar to baseline, which supports the role of mechanical feedback in dynein coordination.
Internal capital market subsidies and industry downturns

We examine whether multisegment firms tend to subsidize operations doing business in industries that experience a major downturn in investment opportunities. The results provide little evidence of subsidization. The likelihood of discontinuation of multisegment operations in these industries does not statistically differ from that of single-segment operations. Similarly, patterns of capital expenditures after the shock do not materially deviate between multisegment and single-segment operations. These results indicate that the internal capital markets of multisegment firms are no less (and no more) efficient than that of single-segment firms in their reaction to a shock to investment opportunities.
Synthesis and photophysics of 4′-R-2,2′;6′,2″-terpyridyl (R = Cl, CN, N(CH3)2) platinum(II) phenylacetylide complexes

Platinum terpyridyl (tpy) phenylacetylide complexes with –Cl, –CN, and –NMe2 substituents on the 4′-position of the tpy ligand were synthesized and characterized. Their photophysical properties were systematically investigated. In addition, theoretical electronic structure calculations using density functional theory (DFT) and time-dependent (TD-DFT) approaches were carried out for complexes 3 and 6; the results of these calculations provided additional information on the nature of the electronic structures of the low-lying electronic states of these complexes, including the electron density distribution and the composition of the frontier molecular orbitals. Complexes 4–6 exhibit moderately intense charge-transfer bands in the visible region, which are assigned to the 1MLCT/1LLCT transitions. In comparison to their corresponding chloride complexes 1–3, these charge-transfer bands become broadened and red-shifted. Complexes 4–6 emit at room temperature in CH3CN and CH2Cl2 solutions and at 77 K in butyronitrile glassy solutions. At room temperature, the emission is tentatively attributed to 3MLCT for 4 and 5, and to a mixture of 3MLCT/3ILCT/3π,π* for 6. Due to the admixture of 3ILCT/3π,π* characters in its emitting state, 6 displays a much higher emission quantum yield and longer emission lifetime compared to 4 and 5. Replacing the chloride co-ligand in 1–3 by phenylacetylide co-ligand clearly enhances the emission and prolongs the lifetime. 3–6 exhibit a broad and moderately intense triplet excited-state absorption in the visible to the NIR region, with large excited-state absorption coefficients and moderately high triplet excited state quantum yields. Therefore, complexes 3–6, especially 6, have potential applications in organic light emitting devices (OLED) and as reverse saturable absorbing materials.
Effect of biliary ligation on manganese accumulation in rat brain.

Neurologic and radiologic disorders have been reported to occur in miners inhaling manganese (Mn)-laden dust and in humans receiving long-term parenteral nutrition. These abnormalities have been attributed to Mn intoxication because of elevated serum Mn concentrations. Because the liver, by way of the bile, is the major route of Mn excretion, it is possible that anything that decreases biliary excretion could increase accumulation of Mn in the brain. The purpose of this study was to determine whether biliary ligation would increase Mn accumulation in the brain of rats that were exposed to deficient or adequate amounts of dietary manganese. The first experiment had a 2 x 3 factorial design, two levels of Mn (0 or 45 μg/g diet) and three surgical treatments (control, sham, or bile-ligation). Animals were sacrificed 10 d after being fed54Mn. In experiment 2, animals that had a sham operation or bile-ligation were sacrificed at 8 time points after being injected intraportally with54Mn complexed to albumin. The biliaryligated animals had a significantly (p < 0.001) smaller percentage of the54Mn in their brains (when expressed as a percentage of whole animal54Mn) than the sham-operated animals. Mn deficiency had a similar effect. However, we did observe an increased accumulation of the radioisotope in the brain over time. Therefore, in short-term studies, biliary-ligated rats do not appear to be a good model for Mn accumulation in the brains of people with cholestatic liver disease.
Response of an Intense Oceanic Current System to Cross-Stream Cooling Events

Abstract Shifts in location and strength of an intense oceanic flow such as the Gulf Stream to a cross-stream gradient in cooling are studied using two-dimensional numerical simulations. The gradient in cooling is imposed by removing more heat from the warm side of the associated baroclinic zone than is removed from the cold side. The initial flow is assumed to be in geostrophic balance. When only a vertical heat exchange associated with the convective overturning induced by surface cooling is allowed, the magnitude of the horizontal pressure gradient is reduced and the flow becomes supergeostrophic. The resulting cross-stream velocity will tend to shift the front toward the region of larger upward surface heat fluxes. When a vertical exchange of momentum is also allowed in the convective adjustment, the reduction of the initial surface velocities due to turbulent momentum exchange is not balanced geostrophically by a reduction in the horizontal pressure gradient. The flow becomes subgeostrophic and a cro...
Myocyte Remodeling During the Progression to Failure in Rats With Hypertension

Regional changes in cardiac myocyte shape during the progression to failure with hypertension have not been clearly established. To address this issue, we examined left and right ventricular myocytes from lean, female spontaneously hypertensive/heart failure rats with compensated hypertrophy (approximately 12 months of age) and congestive heart failure (approximately 24 months of age). During this period, body weight did not change, but heart weight increased 59% and lung weight increased 93%. Left ventricular function declined with the onset of failure. Left ventricular myocyte volume increased 27% exclusively because of myocyte lengthening (29% increase). The onset of left ventricular failure resulted in a 72% increase in right ventricular myocyte volume. Right ventricular myocyte growth, however, was proportional, with a 23% increase in myocyte length and 18% increase in myocyte width. Changes in left ventricular myocyte shape were virtually identical to data collected previously from patients with similar disease, suggesting that this is a relevant animal model. Evidence suggests that left ventricular myocyte transverse growth is defective because dilation and failure were associated with cell lengthening, without a change in myocyte diameter. Although severe hypertrophy was present in the right ventricle as a result of left ventricular failure, myocyte growth was proportional, suggesting that cell shape was properly regulated in this chamber.
Feeding success and selectivity of larval anchoveta Engraulis ringens in a fjord-type inlet from northern Patagonia (Southeast Pacific)

Se investigo la dieta y selectividad de larvas de anchoveta Engraulis ringens durante 4 dias consecutivos (primavera) en el canal Hornopiren, un ambiente tipo fiordo del sur de Chile. Este ambiente estuvo caracterizado por una marcada haloclina alrededor de los 10 m de profundidad, separando aguas salobres y saladas. La oferta potencial de presas, microzooplancton, fue recolectada a 4 profundidades (0, 5, 10 y 30 m), mientras que el ictioplancton fue recolectado en 2 estratos, superficial (0-10 m) y profundo (10-45 m). Los nauplii y copepoditos fueron los principales componentes del microzooplancton. El analisis de 487 contenidos estomacales de larvas de anchoveta indico que se ingirieron volumenes similares de presa en ambos estratos y durante ambas mareas. Sin embargo, en la capa superficial, salobre y mas calida, las larvas de E. ringens ingirieron significativamente menos presas pero de mayor tamano, como nauplii y copepoditos como presas principales. En la capa subsuperficial, en aguas mas frias y saladas, las larvas ingirieron mas presas de menor tamano, con mayor selectividad por los nauplii. La incidencia alimentaria de E. ringens se incremento 2 veces durante la marea llenante, cuando la abundancia de los copepoditos tambien se incremento. Por lo tanto, es posible detectar interacciones biofisicas complejas en los fiordos Patagonicos durante el proceso de alimentacion de los estados larvales de esta especie de importancia comercial, en estrecha relacion con la distribucion espacio-temporal de las presas.
Design issues for a digital x-ray archive accessed over Internet

The design of an electronic archive of digitized images of thousands of xrays collected as part of nationwide health surveys has raised several issues related to user interface design, image presentation and image compression. The project involves developing an image archive implemented with an optical disk jukebox, and user workstations that allow Internet access to the images. This paper describes: the physical layout design of the workstation screens; desirable image processing functions contributing to better viewing and minimizing artifacts; interface design factors contributing to ease-of-use and speed of task completion; and work toward the selection of a suitable image compression technique.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Conspecific cueing in the sea lamprey: do reproductive migrations consistently follow the most intense larval odour?

Conspecific cueing occurs when an organism receives information about habitat quality from the distribution of conspecifics. Consequently, animals should prefer to settle in habitats with high occupancy when conspecific cueing is used. Unlike salmonid fishes, which often acquire chemical recognition of natal streams in early life, sea lamprey, Petromyzon marinus , larvae produce a remarkably potent pheromone that migrating adults use to locate spawning streams. The size of the spawning migration in tributaries to the Great Lakes is correlated with the number of larvae resident to the stream, and therefore the amount of pheromone discharging into the lake. By releasing controlled amounts of larval odour into a lamprey-less stream, we tested the hypotheses that migrating sea lampreys (1) avoid swimming in waters that lack larval odour and (2) actively choose to swim in waters activated with the highest concentration of larval odour. Migrating sea lamprey clearly showed fine-scale movements (
A contextual change account of the directed forgetting effect.

The authors propose that the costs and benefits of directed forgetting in the list method result from an internal context change that occurs between the presentations of 2 lists in response to a “forget” instruction. In Experiment 1 of this study, costs and benefits akin to those found in directed forgetting were obtained in the absence of a forget instruction by a direct manipulation of cognitive context change. Experiment 2 of this study replicated those findings using a different cognitive context manipulation and investigated the effects of context reinstatement at the time of recall. Context reinstatement reduced the memorial costs and benefits of context change in the condition where context had been manipulated and in the standard forget condition. The results are consistent with a context change account of directed forgetting. Directed forgetting is a phenomenon first studied by R. A. Bjork, LaBerge, and LeGrand (1968) whereby people appear to be able to intentionally forget information, making it less accessible to later attempts at recall and reducing interference from that information. The paradigm involves two variations: the item method, which seems to reflect differential encoding of items, and the list method, which does not depend on differential encoding of items (Basden, Basden, & Gargano, 1993). The present work concerns the mechanism of directed forgetting with the list method. Participants are presented two lists of items to study but, immediately after List 1, half of the participants are instructed to forget List 1 (the “forget” group), whereas the remaining half are told to continue remembering List 1 (the “remember” group). The final test requires recall of both lists. Typically, the forget group recalls fewer items from the first list than does the remember group—a finding referred to as the costs of directed forgetting
Preparation of ultrafine FePt nanoparticles by chemical reduction in PAMAM-OH template

Abstract Using dendrimer templates, FePt nanoparticles with narrow size-distribution were prepared by a simple chemical reduction method at room temperature. In this approach, PAMAM-OH dendrimers act as templates in which metal ions are coordinated in, and NaBH4 acts as reductant. The FePt nanoparticles were synthesized in aqueous solution. The as-made FePt nanoparticles are spherical with an average size of ∼3 nm and have the chemically disordered face-center-cubic (fcc) structure. The FePt nanoparticles can be transformed to the face-center-tetragonal (fct) phase after annealing at 700 °C for 1 h. The as-prepared fcc FePt nanoparticles are found to be superparamagnetic at room temperature. After annealing in a reducing atmosphere, the FePt nanoparticles transform to ferromagnetic and show high covercivity. The structural and magnetic properties of the as-made and annealed FePt nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and alternating gradient magnetometry (AGM).
Petri dish PCR: laser-heated reactions in nanoliter droplet arrays.

We report high-speed real-time PCR performed on an unmodified disposable polystyrene Petri dish. The reaction cycle relies solely on an infrared laser for heating; no conventional heater is required. Nanoliter droplets of PCR mixture as water-in-oil emulsions printed in an array format served as individual PCR microreactors. A simple contact printing technique was developed to generate a large array of uniform sized nanoliter droplets using disposable pipette tips. Printed droplets showed variation of less than 10% in volume and the oil/water/polystyrene interface formed a compact droplet microreactor approximately spherical in shape. The uniform droplet array was used to optimize the laser power required for the two heating steps of PCR, annealing/extension and melting, while the ambient conditions were at room temperature. The optical heating allows for an extremely fast heating rate due to the selective absorption of the infrared laser by PCR buffer only and not the oil or polystyrene Petri dish, allowing completion of 40 amplification cycles in ∼6 minutes. The quantitative assay capability of the system is also presented and discussed.
HAEMODYNAMIC EFFECTS AND OUTCOME ANALYSIS OF HYPOTENSIVE EXTRADURAL ANAESTHESIA IN CONTROLLED HYPERTENSIVE PATIENTS UNDERGOING TOTAL HIP ARTHROPLASTY

We have examined the safety of induced hypotension produced by extradural anaesthesia in patients with medically controlled hypertension. The haemodynamic response to induced hypotension was assessed in 38 non-hypertensive and 31 controlled hypertensive patients. All received extradural anaesthesia to T4 or above which decreased mean arterial pressure to 52 mm Hg and 55 mm Hg in normotensive and hypertensive patients, respectively. Cardiac output (thermodilution) was maintained by low dose i.v. infusions of adrenaline (1–5 μg min−1). No differences in the haemodynamic response to induced hypotension were observed in hypertensive patients. Data were collected also from 987 consecutive patients (353 hypertensive and 634 non-hypertensive) undergoing total hip replacement. Patients with hypertension were significantly older (68 vs 60 yr; P
Data Flow Through a Double Process System

A simple model of an element in a data communications network has been investigated. It is shown that the system exhibits a rich dynamical behaviour which under certain conditions may lead to a substantial and sometimes persistent degradation in its performance. Simple guidelines are established for specifying the conditions under which such exotic behaviour, eg: periodic and aperiodic oscillations, can be avoided in order to guarantee reliable and optimal operation of the system. The model is extended to consider multi-process/processor systems.
Development of Eggs from a Hermaphroditic Sea Urchin

REPORTS of hermaphroditic sea urchins are not common. For Arbacia punctulata six examples are recorded over a period of twenty-five years by Harvey1. Since 1956, one report has been made2.
Lost source provenance

As the use of derived information has grown in recent years, the importance of provenance has been recognized, and there has been a great deal of effort devoted to developing techniques to identify individual source tuples used in the derivation of any result tuple. Often, however, the source database may have been updated since the result was derived, and the source tuples of interest are not in the database any more. In such situations, the provenance management system has to reconstruct relevant historical fragments of the source database as they were at derivation time. In this paper, we develop techniques to address this problem. Our experimental assessment shows that these techniques do so efficiently, and with low storage overhead.
Hypoxia-reoxygenation induces premature senescence in FA bone marrow hematopoietic cells

Hematopoietic cells are often exposed to transient hypoxia and reoxygenation as they develop and migrate. Given that bone marrow (BM) failure occurred in patients with Fanconi anemia (FA), we reason that hypoxia-then-reoxygenation represents a physiologically relevant stress for FA hematopoietic progenitor/stem cells. Here we show that expansion of Fancc–/– BM cells enriched for progenitor and stem cells was significantly decreased after 2 continuous cycles of hyperoxic-hypoxic-hyperoxic treatments compared with wild-type (WT) BM cells. This inhibition was attributable to a marked decrease of lineage-depleted (Lin–) ScaI– c-kit+ cells and more primitive Lin– ScaI+ c-kit+ cells in Fancc–/– BM cells following reoxygenation. Evaluation of the cell-cycle profile of long-term BM culture (LTBMC) revealed that a vast majority (70.6%) of reoxygenated Fancc–/– LTBMC cells was residing in the G0 and G1 phases compared with 55.8% in WT LTBMC cells. Fancc–/– LTBMC cells stained intensely for SA-β-galactosidase activity, a biomarker for senescence; this was associated with increased expression of senescence-associated proteins p53 and p21WAF1/CIP1. Taken together, these results suggest that reoxygenation induces premature senescence in Fancc–/– BM hematopoietic cells by signaling through p53, up-regulating p21, and causing senescent cell-cycle arrest. Thus, reoxygenation-induced premature senescence may be a novel mechanism underlying hematopoietic cell depletion and BM failure in FA.
Adhesion of styrenic triblock copolymers to miscible blends of polystyrene and a phenylene ether copolymer

Abstract The adhesion of a triblock copolymer having short styrene end-blocks and a hydrogenated mid-block to a polystyrene containing substrate was studied using both lap shear and peel test methods. The two approaches gave very similar results. Within the limits examined, the adhesive bond strength did not depend significantly on bonding temperature or time. However, the adhesive strength did increase substantially as a phenylene ether copolymer or PEC, essentially poly(phenylene oxide), was added to the substrate. This effect is believed to be the result of the exothermic mixing of PEC with polystyrene that causes an additional driving force, other than combinatorial entropy, for interpenetration of segments of the substrate and the styrenic phase of the block copolymer at the interface. Attempts to use a block copolymer having longer styrenic segments resulted in adhesive bond strengths so large that cohesive failure occurred first.
EC-STM Studies of Te and CdTe Atomic Layer Formation from a Basic Te Solution

The cyclic voltammetry of Te on Au is markedly affected by pH. This fact can be used to advantage when designing an electrodeposition cycle for CdTe. For instance, if a pH 2 Te solution is used, the underpotential deposition (UPD) potential for Te is 0.8 V positive of that for Cd. However, if a pH 9.2 Te deposition solution is used, the potential for Te UPD coincides with that for Cd, greatly simplifying the development of an electrochemical atomic layer epitaxy (EC-ALE) cycle. This report describes electrochemical scanning tunneling microscopy (EC-STM) studies of Te deposition on Au(111) and Au(100) from basic media. Several structures were observed on Au(111): a (6 × 6 ) tellurite adlayer which spontaneously adsorbed prior to Te formation, a 1/4 coverage (2 × 2)-Te, and a 1/3 coverage (2 X 10)-Te. While on Au(111), a 1/3 coverage (√3 × √3)-Te with (13 × 13) light domain walls, and two (3 × 3)-Te structures, with coverages of 4/9 and 5/9, were observed. Results of the formation of the first CdTe compound monolayer using an EC-ALE cycle which includes Te deposition from a basic solution are also included.
Commentary on “spirituality and stress management in healthy adults

The purpose of this pilot study was to determine whether a 6-week spiritual intervention (SPIRIT-6©) would reduce stress and increase spiritual well-being in healthy community residents. An additional purpose was to explore how healthy adults describe their spirituality. The SPIRIT-6© intervention required weekly attendance at 90-minute sessions that allowed for group expression of spirituality. Session topics included the meaning and importance of spirituality and religion, how spirituality is expressed to others, forgiveness, and spiritual awareness and well-bring. Four booster sessions were also held during the year to reinforce the intervention. The researchers used the term spirituality to refer to both spirituality and religion.
Functional complementation of internal deletion mutants in the lactose permease of Escherichia coli.

Abstract Using the lactose permease of Escherichia coli, a well-characterized membrane protein with 12 transmembrane domains, we demonstrated that certain paired in-frame deletion constructs complement each other functionally. Although cells expressing the deletion mutants individually are unable to catalyze active lactose accumulation, cells simultaneously expressing specific pairs of deletions catalyze transport up to 60% as do cells expressing wild-type permease. Moreover, complementation clearly does not occur at the level of DNA but probably occurs at the protein level. Remarkably, functional complementation is observed only with pairs of permease molecules containing large deletions and is not observed with missense mutations or point deletions. Although the mechanism of functional complementation is obscure, the findings indicate that certain pairs of permease molecules containing specific internal deletions can interact to form a functional complex in the same way phenomenologically as do independently expressed polypeptides corresponding to different N- and C-terminal portions of the permease.