cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure of a Eukaryotic CLC Transporter Defines an Intermediate State in the Transport Cycle

CLC proteins transport chloride (Cl(-)) ions across cell membranes to control the electrical potential of muscle cells, transfer electrolytes across epithelia, and control the pH and electrolyte composition of intracellular organelles. Some members of this protein family are Cl(-) ion channels, whereas others are secondary active transporters that exchange Cl(-) ions and protons (H(+)) with a 2:1 stoichiometry. We have determined the structure of a eukaryotic CLC transporter at 3.5 angstrom resolution. Cytoplasmic cystathionine beta-synthase (CBS) domains are strategically positioned to regulate the ion-transport pathway, and many disease-causing mutations in human CLCs reside on the CBS-transmembrane interface. Comparison with prokaryotic CLC shows that a gating glutamate residue changes conformation and suggests a basis for 2:1 Cl(-)/H(+) exchange and a simple mechanistic connection between CLC channels and transporters.
Household assets, academic expectations, and academic performance among Ghanaian junior high school students: Investigating mediation

Abstract The potential relevance of households' asset ownership in promoting academic success of children has spurred empirical investigation into the relationship between assets and academic performance. However, current research has mostly ignored the diverse pathways by which asset ownership may be connected to academic performance. This study focuses on one of these largely ignored pathways by examining how parents' and youth's expectations may intervene in the relationship between household asset ownership and the academic performance of junior high school students in Ghana. Using the asset-effect framework as a theoretical guide, the study uses observational data and multilevel structural equation modeling to address the aims of the study. Results show that at the 95% confidence level, there is no direct relationship between household asset ownership and academic performance but compelling evidence that assets are associated indirectly with academic performance through youth's academic expectations. A group invariance test also finds no statistically significant gender difference in the mediational role of youth's expectations. Policy initiatives ought to reflect the many ways that asset ownership affects students' academic success. Teachers should be trained to not only teach course content but also help improve students' academic expectations and psychological well-being.
Protein conformational search with geometric projections

Protein structure prediction remains a central challenge in computational structural biology. Even at the coarse-grained level of detail, the protein conformational space is vast, and available energy functions contain many false local minima. In order to effectively characterize this space, a conformational search must sample a geometrically-diverse set of low-energy conformations. Our recently published FeLTr framework achieves this goal by employing a low-dimensional geometric projection layer to bias conformational sampling towards unexplored regions of the search space. In this work we present a new geometric projection layer based on the effective connectivity measure, which encapsulates interatomic distances within a conformation. Extensive analysis indicates that effective connectivity allows equipping the high-dimensional conformational search with an effective projection layer. On several target proteins, this layer improves significantly over our previous work, resulting in sampling of conformations with significantly lower lRMSDs to the known native structure.
Heritability of the Plasma Transferrin Protein in Three Species of Microtus

ALTHOUGH variation in the electrophoretic mobility of the plasma transferrin protein has been demonstrated in a number of mammals1–13, not all investigations include work on the actual heritability of the protein. Cohen6, Shreffler7 and Ashton and Braden14 have all worked on the genetical control of this protein in the laboratory mouse (Mus musculus), but while the first two workers refer to the transferrin proteins, the latter two make reference to β-globulins. This occurs also in other instances in the literature. I therefore suggest that when an iron-binding method is used to identify this protein, as is the case in most of the work already carried out, perhaps the functional name, transferrin, would be more accurate than the general term, β-globulin, for it is possible that not all the latter is being stained. This communication reports data gathered on the inheritance of the transferrin protein in the meadow vole (Microtus pennsylvanicus), the prairie vole (M. ochrogaster), and the beach vole (M. breweri).
Rapid Chromosome and Sex-Chromatin Staining with Pinacyanol

This simple and reliable 10-min procedure for producing uniformly and intensely stained, as well as fade-resistant, chromosome and sex-chromatin preparations uses pinacyanol chloride as the dye. Slides are extracted in 5 N HC1 at 20-23 C for 2 min, washed in running tap water for 2 min, stained in 0.25% pinacyanol chloride solution (made up in 70% methanol) for 45 sec, differentiated in Wright's buffer solution (pH 6.4-6.5) for 45 sec, washed in running tap water for 5 sec, dehydrated in 2 changes, 1 min each, of absolute tertiary butanol, cleared in 3 changes of xylene, a minimum of 30 sec each, and mounted in a neutral synthetic resin such as Permount.
Ultrastructure of a new cell in the gills of the air-breathing fish Helostoma temmincki.

A cell which has not been previously described was observed in the gills of Helostoma temmincki . This cell contains long mitochondria, over 3 μ , in parallel array, surrounded by an extensive system of coated channels. There is a 200 A space between the membranes of the mitochondria and the channels. The particles coating the channels are seen in the center of this space. These particles are about 80 A in diameter with 60 A spaces between them. A connection is sometimes seen between the membranes of the channels and the particles. The close association between mitochondria and the coated channels is a characteristic of cells thought to be functioning in the active transport of ions and water. This morphological similarity to other transport cells, and additional experiments in which the specimens were subjected to gradients of hypertonic and hypotonic water, suggest that this cell also functions in the active transport of a substance.
Have we achieved a unified model of photoreceptor cell fate specification in vertebrates

How does a retinal progenitor choose to differentiate as a rod or a cone and, if it becomes a cone, which one of their different subtypes? The mechanisms of photoreceptor cell fate specification and differentiation have been extensively investigated in a variety of animal model systems, including human and non-human primates, rodents (mice and rats), chickens, frogs (Xenopus) and fish. It appears timely to discuss whether it is possible to synthesize the resulting information into a unified model applicable to all vertebrates. In this review we focus on several widely used experimental animal model systems to highlight differences in photoreceptor properties among species, the diversity of developmental strategies and solutions that vertebrates use to create retinas with photoreceptors that are adapted to the visual needs of their species, and the limitations of the methods currently available for the investigation of photoreceptor cell fate specification. Based on these considerations, we conclude that we are not yet ready to construct a unified model of photoreceptor cell fate specification in the developing vertebrate retina.
The use of bond paths for quantitatively characterizing bond strain

Abstract The concept of the bond path as a means for characterizing individual strained bonds is developed in detail and applied to a variety of molecules. A reference path is defined in terms of the superposed electronic densities of the free atoms, and a “bond deviation index” is introduced, for expressing quantitatively the difference between the actual and the reference bond paths. This difference is taken as indicating the degree of strain in the bond. It is shown that bond paths can be significantly affected by not only neighboring bonding electrons, but by lone pairs as well, as in the H 2 O and NH 3 molecules.
The allocative equivalence of contracting and regulation

Demsetz broke new ground in the analysis of natural monopoly when he proposed that "the theory of natural monopoly is deficient for it fails to reveal the logical steps that carry it from scale economies in production to monopoly price in the market place" [1968, p. 56]. Rather than the conventional alternatives stressed by economists to deal with natural monopolyprivate monopoly, public monopoly, or public regulation-Demsetz proposed an ingenious bidcling competition to cut the link between unfettered natural monopoly and monopoly price.' This bidding competition consists of potential suppliers submitting price bids with the implicit proviso that a firm will serve all demanders at that price (prices). What results from this competition is that competitive bidding promotes a market outcome where the bidder with the lowest tong-run average cost function wins the contract to operate the natural monopoly at an average-cost price. By the route of competitive bidding and a contracting mechanism Demsetz is able to effect an average-cost pricing solution for natural monopolies, and in his model there is no reason that scale economies bear any particular relation to the number of bidders for the right to operate the natural monopoly. By contrast the regulator attempts to set price equal to the average cost of the regulated firm, but information about the firm's cost conditions is not free. Demsetz's system generates the lowest available average-cost price while the regulator presumably lacks the relevant information to perform the same feat.: As Demsetz wou!d
Cutting the leash

The structural comparison of a Gag fragment comprising matrix and the N-terminal domain of capsid with mature matrix and capsid provides insight into the structural rearrangement upon viral maturation. Proteolytic cleavage of Gag triggers β-hairpin formation in capsid.
Deep vein thrombosis of lower extremity: direct intraclot injection of alteplase once daily with systemic anticoagulation--results of pilot study.

Purpose: To prospectively evaluate the outcome of patients with acute deep vein thrombosis (DVT) of the lower extremity treated with “lacing” of the thrombus with alteplase (recombinant tissue plasminogen activator, or rTPA). Materials and Methods: This HIPAA-compliant study was approved by the Institutional Review Board of the National Heart, Lung, and Blood Institute and was funded by the National Institutes of Health. After giving written consent, 20 patients with first-onset acute DVT were treated with direct intraclot lacing of the thrombus with alteplase (maximum daily dose, 50 mg per leg per day; maximum of four treatments) and full systemic anticoagulation. Alteplase was chosen because its high fibrin affinity obviates continuous infusion of this thrombolytic agent. Ventilation-perfusion (V/Q) scans were performed for evaluation of embolic risks, and clinical and imaging examinations were supplemented with pharmacokinetic studies to enable further assessment of treatment outcomes. Results: The 20 ...
Precedence-enabled per-hop behaviour: impact on TCP and UDP flows

The author proposes and analyses an approach to support both precedence and preemption (P&P) and QoS handling in common packet transport infrastructures. Precedence has to do with the relative importance of the information content, whereas preemption has to do with mechanisms to deny lower precedence traffic access to network resources in favour of higher precedence traffic, when necessary. The author's approach to this duality is to enhance active queue management (AQM) techniques to provide P&P capabilities and rely on standard, well-studied QoS schedulers, for example, Weighted Round Robin, Class-Based Weighted Fair Queuing, etc., for handling QoS requirements. The present scheme allows low-order queues (within the context of QoS handling) to plead up to the next higher-order queue for help in alleviating queue congestion under periods of communication link overload. The scheme is referred as the cross-queue-AQM (CQ-ACM) scheme and can be extended to higher numbers of queues and any type of scheduler. Through extensive simulation studies, the performance of CQ-AQM scheme under heavy traffic limits is investigated, where preemption is required. The performance metrics of interest to this analysis are packet delay, packet loss and throughput as a function of the packet QoS class and P-L. Further, two new metrics of merit, Gain and System Efficiency, are defined, which are specific to P&P considerations. The studies concentrated on both flow-controlled and non-flow-controlled traffic, as well as mixed traffic conditions. Simulation results show that the algorithms perform extremely well for all cases studied.
Level structure of 101Rh from the decay of 8.5 h 101Pd

Abstract The level structure of 101 Rh has been investigated from the decay of 8.5 h 101 Pd. Singles γ-ray energy and intensity measurements were taken with a 25 cm 3 high-resolution Ge(Li) detector in an anti-Compton arrangement which employed a large Nal(TI) annular detector. Extensive γγ coincidence measurements were made with a Ge(Li)-Ge(Li) and a NaI-Ge(Li) arrangement with the Ge(Li) detector under Compton suppression. Triple γγγ coincidence measurements were taken in a NaI-Ge(Li)-NaI arrangement with the Ge(Li) detector under Compton suppression. The low-energy γ-rays and X-rays were studied with a high-resolution Si(Li) X-ray spectrometer. Conversion electron measurements were made with Si(Li) detectors and α K values were determined for the most intense transitions. From these data it was concluded that levels at 157.32, 181.78, 305.3, 355.14, 478.00, 747.67, 905.61, 974.7, 978.42, 1035.5, 1057.7, 1320.4, 1359.31, 1470.82, 1696.27, 1789.26, 1820.22 and 1911.23 keV are populated in the decay of 8.5 h 101 Pd. From log ft and α K values determined in this work and from γ-ray intensity information definite J π assignments were made to a number of levels and limits for the J π values were placed for the rest of the levels in 101 Rh. The fraction of decay of the 4.5 d isomeric state by an isomeric transition was measured to be 0.072±0.004. The level structure and the level trends in the 99, 101,103, 105 Rh isotopes are examined and discussed in relation to recently published results on calculated levels in these isotopes on the basis of an extended pairing-plusquadrupole model for the nucleus.
Empirical Green's function study of the January 17, 1994 Northridge, California earthquake

The January 17, 1994 Northridge main-shock was analyzed using an empirical Green's function approach to estimate the spatial and temporal distribution of fault slip. Far-field source time functions obtained from seismograms recorded by the Berkeley Digital Seismic Network (BDSN) and TERRAscope stations reveal the distributed nature of the source and the presence of a second large subevent. The location of the fault beneath the San Fernando valley as well as the updip directivity of the rupture contributed to the locally heavy damage due to this earthquake.
Across the Divide: Reflecting on University Collaboration

This paper is a reflective accounting of a collaboration between a mathematician, interested in the mathematics content being delivered in education courses, and a mathematics educator, eager to learn more mathematics in order to know what questions to ask her students to provoke their thinking. Two university professors from different disciplines describe a type of teaming between academics in which two teachers can have a profound effect on each other's teaching methodology without ever setting foot in each other's classrooms. The professors met regularly, out of class, to share their passion, pedagogy and content knowledge. As they reflect on the 'lessons learned' from this noninvasive collaboration model they discover that these metacognitive discussions led to dramatic and subtle changes in their teaching practices, as well as a refinement of their individual beliefs about teaching and learning mathematics.
Glorin-regulated protein synthesis in Polyspondylium violaceum.

Abstract Protein synthesis by Polyspondylium violaceum in response to the chemoattractant glorin was analyzed by two-dimensional gel electrophoresis to determine if glorin can affect gene expression. When cells developing in a shaking suspension culture were given glorin, five proteins exhibited significantly increased and three proteins exhibited decreased incorporation of l -[35S]methionine. Glorin was active from 10–1000 nM, a concentration range within which cells are chemotactically active. The extent of the response was dependent on the concentration and the length of exposure to glorin. This evidence suggests that glorin may act in part to mediate changes in gene expression during development.
Nitrate retention in a sand plains stream and the importance of groundwater discharge

We measured net nitrate retention by mass balance in a 700-m upwelling reach of a third-order sand plains stream, Emmons Creek, from January 2007 to November 2008. Surface water and groundwater fluxes of nitrate were determined from continuous records of discharge and from nitrate concentrations based on weekly and biweekly sampling at three surface water stations and in 23 in-stream piezometers, respectively. Surface water nitrate concentration in Emmons Creek was relatively high (mean of 2.25 mg NO3–N l−1) and exhibited strong seasonal variation. Net nitrate retention averaged 429 mg NO3–N m−2 d−1 and about 2% of nitrate inputs to the reach. Net nitrate retention was highest during the spring and autumn when groundwater discharge was elevated. Groundwater discharge explained 57–65% of the variation in areal net nitrate retention. Specific discharge and groundwater nitrate concentration varied spatially. Weighting groundwater solute concentrations by specific discharge improved the water balance and resulted in higher estimates of nitrate retention. Our results suggest that groundwater inputs of nitrate can drive nitrate retention in streams with high groundwater discharge.
Using Moment Equations to Understand Stochastically Driven Spatial Pattern Formation in Ecological Systems

Abstract Spatial patterns in biological populations and the effect of spatial patterns on ecological interactions are central topics in mathematical ecology. Various approaches to modeling have been developed to enable us to understand spatial patterns ranging from plant distributions to plankton aggregation. We present a new approach to modeling spatial interactions by deriving approximations for the time evolution of the moments (mean and spatial covariance) of ensembles of distributions of organisms; the analysis is made possible by “moment closure,” neglecting higher-order spatial structure in the population. We use the growth and competition of plants in an explicitly spatial environment as a starting point for exploring the properties of second-order moment equations and comparing them to realizations of spatial stochastic models. We find that for a wide range of effective neighborhood sizes (each plant interacting with several to dozens of neighbors), the mean-covariance model provides a useful and analytically tractable approximation to the stochastic spatial model, and combines useful features of stochastic models and traditional reaction-diffusion-like models.
Adaptive feature annotation for large video sensor networks

We present an adaptive feature extraction and annotation algorithm for articulating traffic events from surveillance cameras. We use approximate median filter for moving object detection, motion energy image and convex hull for lane detection, and adap- tive proportion models for vehicle classification. It is found that our approach outperforms three-dimensional modeling and scale-inde- pendent feature transformation algorithms in terms of robustness. The multiresolution-based video codec algorithm enables a qual- ity-of-service-aware video streaming according to the data traffic. Furthermore, our empirical data shows that it is feasible to use the metadata to facilitate the real-time communication between an infrastructure and a vehicle for safer and more efficient traffic control. © 2013 SPIE and IS&T (DOI: 10.1117/1.JEI.22.4.041110)
The development of experimental techniques for the study of helicopter rotor noise

The features of existing wind tunnels involved in noise studies are discussed. The acoustic characteristics of the MIT low noise open jet wind tunnel are obtained by employing calibration techniques: one technique is to measure the decay of sound pressure with distance in the far field; the other technique is to utilize a speaker, which was calibrated, as a sound source. The sound pressure level versus frequency was obtained in the wind tunnel chamber and compared with the corresponding calibrated values. Fiberglas board-block units were installed on the chamber interior. The free field was increased significantly after this treatment and the chamber cut-off frequency was reduced to 160 Hz from the original designed 250 Hz. The flow field characteristics of the rotor-tunnel configuration were studied by using flow visualization techniques. The influence of open-jet shear layer on the sound transmission was studied by using an Aeolian tone as the sound source. A dynamometer system was designed to measure the steady and low harmonics of the rotor thrust. A theoretical Mach number scaling formula was developed to scale the rotational noise and blade slap noise data of model rotors to full scale helicopter rotors.
Graded metareflectors for wave manipulation and control at the nanoscale

Optical metasurfaces, or planarized metamaterials, are based on engineered subwavelength inclusions intentionally designed to provide desired advanced functionalities, unavailable with conventional gratings, by exploiting their anomalous localized response. Metasurfaces have been investigated both theoretically and experimentally in various recent studies, but most of the available examples are limited to strictly periodic structures. In this work we introduce a novel planarized metasurface reflector composed of deeply subwavelength nonperiodic inclusions arranged to impart the desired arbitrary phase distribution at the nanoscale. We obtain exciting and unique wave interaction properties, and we outline their potential applications at optical frequencies, demonstrating a novel photon management approach for broadband light absorption enhancement in thin-film solar cells, an efficient, low-dispersion integrated on-chip coupler, and a new concept for ultrathin optical carpet cloaks.
Hydro-ecology of groundwater-dependent ecosystems: applying basic science to groundwater management

AbstractEffective policies to protect groundwater-dependent ecosystems require robust methods to determine the environmental flows and levels required to support species and processes. Frameworks to support groundwater management must incorporate the relationships between hydrology and species and ecological processes. These hydro-ecological relationships can be used to develop quantitative, measurable thresholds that are sensitive to changes in groundwater quantity. Here we provide a case study from a group of fens in central Oregon, USA, that are used for cattle watering, but also support numerous sensitive species. We developed quantitative relationships between the position of the water table and wetland indicator plant species and the process of peat development, to propose groundwater withdrawal thresholds. A maximum depth to water table of –0.9 to –34.8 cm for fen plants and –16.6 to –32.2 cm for peat accretion can be tolerated in these wetlands. Defining hydro-ecological relationships as threshold...
Behaviour of the female beaugregory damselfish (Stegastes leucostictus)

Much less is known about the behaviour of female beaugregory damselfish than about males of the species. This study was initiated to determine behavioural patterns and interactions of female beaugregories on the back reef of Discovery Bay Marine Laboratory, North shore of Jamaica. Females fed, patrolled, and chased intruders in a significantly larger area and ate significantly more per 15-min observation period than did males. Males spent significantly more time patrolling their territories and chased significantly more total intruders than did females. However, this difference in total chases comes from the fact that males chased the bluehead wrasse, an egg predator, significantly more often than did females while all other species of intruder were chased the same by both sexes. The distance that females travelled from their homesite to court was significantly positively correlated to female body length. This increased distance travelled may relate to mate assessment. Female beaugregory damselfish may be able to be more selective in their choice of mate with increased size and distance travelled.
Tissue levels of active and total renin, angiotensinogen, human chorionic gonadotropin, estradiol, and progesterone in human placentas from different methods of delivery

The components of the renin system are present in placental tissue, but their function in this tissue is not known. We investigated the relative distribution of the various components throughout the placenta to determine whether the distribution is consistent with a role for them in parturition or in stimulation or inhibition of placental hormone biosynthesis. Thus, active and total renin were measured in fetal membranes (chorion laeve and amnion) and in discoid placenta (chorion frondosum and chorion plate) of women who were delivered vaginally (n = 12) or by cesarean section with (n = 6) or without labor (n = 9). The interrelationships between active and total renin and angiotensinogen, progesterone, hCG, and estradiol concentrations were investigated. Labor had no significant effect on the concentration of active or total renin, angiotensinogen, hCG, or estradiol in any part of the placenta. Tissue progesterone concentrations were higher in placentas from women who underwent vaginal deliveries than in those who had cesarean sections with or without labor (P less than 0.02). The chorion laeve had 20 times more total renin per g than the discoid placenta and 3 times more than the amnion. In contrast the discoid placenta had 5 times more hCG per g and 3 times more progesterone per g than the fetal membranes. The concentration of estradiol was lower in amnion, while that of angiotensinogen was lower in the chorion frondosum than in all other regions. The tissue concentrations of active renin, prorenin, or total renin were not related to those of any of the other hormones. Altogether these data do not provide evidence of a role for the placental renin system in parturition or placental hormone biosynthesis.
In the words of experts: the interpretive process of the food irradiation debate

Irradiation has been touted as a way to safeguard the food supply. When we asked oyster harvesters in Southern Louisiana about their awareness and knowledge concerning this postharvest technology, we found that nearly half of them had never heard about it. We decided to look closer at the irradiation debate that has been taking place in two regional newspapers (Louisiana and Florida) to try to understand why the coverage of this issue may not be of interest to oyster harvesters. We interviewed reporters and sources who were involved in this coverage, and argue that one possible reason is that journalists have decided who the experts are on the issue, and have framed the controversy over irradiation as a public relations battle, and sources have not been overly opposed to this type of newswork. This type of journalism may have the effect of alienating those individuals whose livelihoods may be greatly impacted by the adoption of this technology. In addition, these findings have implications for individuals and groups interested in attracting the media spotlight concerning food safety issues. L'irradiation est une technologie utilisable pour proteger les aliments. Cependant il se trouve que pres de la moitie des ostreiculteurs du sud de la Louisiane n'a jamais entendu parler de cette technologie. La couverture du debat sur l'irradiation des aliments dans deux journaux locaux americains montre que les journalistes ont designe eux-memes les experts du domaine et qu'ils ont presente la polemique sur l'irradiation comme un combat entre deux opinions. Ce type de journalisme risque de decourager les personnes dont les moyens d'existence peuvent etre largement modifies par l'adoption de cette technologie.
Technical Note Simulation of radiances for future AVHRR platforms with the AVIRIS spectral radiometer

Abstract The spectral waveband and spatial resolution of two new satellite imaging channels is simulated through the use of airborne multi-spectral radiometer observations. Numerical integration of multiple radiances obtained by the NASA AVIRIS instrument is used to represent the 1.6μm channel of the AVHRR-K scanning radiometer and the 0-85μm channel which may be included on AVHRR-N. Pixel averaging of the high spatial resolution AVIRIS scans is used to study the impact of the satellite field of view. The AVIRIS instrument allows specific wavelengths to be identified which most effectively separate cloud and land types. In addition, near-infrared channel ratios are shown to discriminate scene type populations. Spectral coherence scattergrams are also tested as a method of improving the distinction between pixel types.
Anodic Polarization of Titanium and Titanium Alloys in Hydrochloric Acid

Abstract : Commercially pure titanium and the alloys studied exhibited active to passive transitions in HCl. Increasing the acid concentration increased the critical current for passivity and shifted the critical potential for passivity in the noble direction. Increasing the temperature served only to increase the critical current for passivity. Activation energies for the anodic polarization process were the right order of magnitude for a reaction controlled by reactivity at the metal surface. For the alpha-beta alloy 6Al-6V-2Sn the critical current for passivity increased as the ratio of amounts of beta-to-alpha phase decreased with increasing strength level. The addition of Fe(3+) and Cu(2+) (0.03 M) to the HCl facilitated passivation of the metal and its alloys. The maximum dissolution current densities for the metal and alloys in HCl were double those in H2SO4. Pitting of several of the alloys occurred in HCl but not in H2SO4. (Author)
Fatty acid composition of phospholipids from chick neural retina during development

The fatty acid composition of retina phospholipids from developing chicks was investigated to determine what changes, if any, occur in the relative levels of polyunsaturated fatty acids. Embryonic chicks were killed at 3-day intervals from day 6 through hatching (day 21), and at 1 week post-hatch. Fatty acids were prepared from retina phospholipids and were analysed by capillary gas-liquid chromatography. A comparison of the composition of yolk taken on day 6 with retinas isolated on that day revealed a much greater proportion of polyunsaturated fatty acids in the latter, suggesting an ability of the embryo to metabolize selectively unsaturated fatty acids at this early stage of development. Throughout the time course studied, saturated fatty acids constituted 50% of all fatty acids, most of which was due to palmitic acid (16:0; 33-41%). Among other saturated fatty acids, myristic acid (14:0) increased to maximal levels by day 18, then declined, while stearic acid (18:0) was minimal on day 12 and then increased. Polyunsaturated fatty acids varied between 14 and 23% of total fatty acids, depending on the developmental stage. One of the most remarkable changes in polyunsaturated fatty acids occurred in the levels of 22:4 (n-6). The proportion of this single fatty acid decreased from 9.4 to 2.4% between days 15 and 18. Relative levels of 22:5 (n-6) increased significantly between day 21 and 1 week post-hatch, from 1.1 to 3.2%. In this same time period, the proportion of 22:6 (n-3), the fatty acid known to be prominent in the outer segments of rod-dominant retinas, did not change.(ABSTRACT TRUNCATED AT 250 WORDS)
The podocyte cell coat in experimental nephrosis.

We have investigated by light and electron microscopy the cell coat morphology of podocytes in rats with aminonucleoside-induced nephrotic syndrome. Blocks of tissue were stained before embedding with two different preparations of colloidal iron (CI) and with ruthenium red (RR). Ultrathin sections of Epon-embedded tissue were stained with acid solution of phosphotungstic acid (PTA) and with the periodic acid-silver methenamine technique (PASM). On light microscopy reduced stainability of the glomeruli after CI impregnation, as shown by the Prussian blue reaction, was evident in all the test animals as compared with controls. On electron microscopy the same CI techniques showed a well-preserved cell coat in all the test animals especially on the outer surface of podocytes. The same results were obtained with RR. This procedure stained also the lamina densa of the basement membrane and the thin cell coat of podocytes facing the basement membrane. In the PASM and PTA preparations, the cell coat was much thinner than after CI or RR and appeared as a continuous layer on the surface of podocytes in test and control animals. We suggest that the reduced CI staining is a consequence of the reduction of podocyte surface associated with foot process loss.
Target Tracking By Three-Dimensional Cellular Logic

AbstractCellular logic has been available to accomplish image processing since the early 1960s. With the rapid decline in the cost of digital circuitry, it is now practical todevelop advanced systems employing cellular logic and other types of parallelism that arewell suited to image and sensor array analysis. Three recent systems, CLIP4 DAP, and1MPPshow use of these principles and can attain, respectively, rates of 109, 101u, and 101pixel operations per second. This paper describes: 1) the nature of cellular logic, 2)the relationship of cellular computers to the diverse digital devices available today, 3)the concerns in applying three -dimensional cellular logic to track detection and, 4) trackdetection experiments.IntroductionThe commercial use of two -dimensional cellular logic to detect points objects (bloodcells) in medical images' at Perkin -Elmer and in infrared (FLIR) data2 at EnvironmentalResearch Institute of Michigan (ERIM) prompted our investigating the applicability ofthree -dimensional cellular logic to the detection and description of target tracks.
Histamine-sensitive Adenylate Cyclase in Mammalian Brain

THERE is increasing interest in the possibility that histamine may be a neurotransmitter in the mammalian central nervous system (CNS). Electrophysiological evidence supports the existence of histamine receptors in nervous tissue through which neuronal excitability can be regulated. For example, the firing rate of certain neurones in the brain is depressed by histamine and this depression is specifically blocked by the H2 antagonist, metiamide1. In addition, histamine influences the electrical excitability of neurones in the superior cervical ganglion2. Certain neurotransmitters may exert some of their effects in nervous tissue by stimulating the formation of cyclic AMP. It is therefore of interest that histamine raises cyclic AMP levels in brain slices3–7, as do several other putative neurotransmitters, such as noradrenaline, dopamine and 5-hydroxytryptamine (5-HT). Furthermore, a dopamine-sensitive adenylate cyclase has been found in homogenates of rat caudate nucleus and olfactory tubercle, with properties very similar to those of the dopamine receptor in mammalian brain8–10. We report here the occurrence of an adenylate cyclase which is activated by low concentrations of histamine in several regions of guinea pig brain. This histamine-sensitive adenylate cyclase has the pharmacological properties of an H2 receptor. The results indicate that the actions of histamine on H2 receptors in the CNS may be mediated through cyclic AMP.
Stimulation of cell-free ring expansion of penicillin N by sonication and Triton X-100

Cell-free protoplast lysates of Cephalosporium acremonium convert penicillin N to deacetoxycephalosporin C by ring expansion. Filtration eliminates 90% of their activity, indicating that the enzyme activity is particulate. The surfactant Triton X-100 or sonication of the lysate stimulates protoplast lysate activity. Active extracts could be produced by merely sonicating intact mycelia.
An intelligent web-based decision support tool for enhancing asthma guideline adherence

Asthma is a leading chronic disease of children and currently affects about 6.2 million (8.5%) children in the United States. National Asthma Education and Prevention Program (NAEPP) Guidelines recommend a multimodal chronic care approach. However, both of the 1997 and 2007 NAEPP guidelines have not been widely adopted by primary care clinicians because implementing the guidelines in primary care setting requires changes and redesign in clinical practice and the use of Health Information Technology (HIT) to facilitate the changes. Existing electronic asthma care systems are either inefficient to be used in real clinical encounter or provide only after-fact feedback. This paper introduces a web-based clinical decision support system that integrates intelligent computer technology, complex guideline guidance and knowledge necessary for operationalizing guidelines to improve decision making for asthma care. This system is capable of collecting guideline-suggested diagnostic measures, automatically assessing asthmatic severity and control categories based on collected measures as well as providing guideline-appropriate medication regimen. The system is implemented in a model-view-controller principle with three tiers: web-server, core reasoning algorithms and back-end database. We develop the system in conjunction with University of Connecticut Health Center to enable preliminary evaluation of the decision support system and to design an efficient and user-friendly interface that requires minimum changes in the clinical routine for primary care physicians to adapt to the system when deployed into clinical settings.
Recruitment of Minority Teachers: Issues, Problems, Facts, Possible Solutions:

Spellman addresses issues and prob lems in recruiting minorities into teach ing, including the diminution of minority teacher candidates, the influence of competency tests for admittance to teacher...
Change of parasites

Modern Parasitology: A Textbook of Parasitology. Edited by F.E.G. Cox. Blackwell Scientific/Blackwell Mosby: 1982. Pp.346. Pbk £12.50, $23.95.
Particulate air pollutants: A comparison of British “Smoke” with optical absorption coefficient and elemental carbon concentration

Abstract Atmospheric aerosol samples collected simultaneously on four different filter media support the hypothesis that reflectance, as measured by the British “Smoke” method, is controlled by the optical absorption coefficient of the aerosol. An additional comparison shows that the British “Smoke” measure may be used to estimate concentrations of sub-μm, particulate, elemental carbon. Poorer correlations are suggested for the mass concentration of the particles suspended in air.
Preparing End User Support Specialists

Abstract Specializations within the field of information systems (IS) have become common. End user support (EUS) is a growing area that requires further examination by academia and consideration as a new IS specialization. In this article, the authors examine two views of an IS course dealing with EUS. Each course went through a similar evolution, but faculty expertise prevailed in the final development of each course. Both academic programs use a traditional approach combining theory and student projects to simulate the duties required in user support. The evolution of both courses continues.
Correlation of the Bender-Gestalt and WISC for Negro children.

A significant relationship between Bender-Gestalt performance and intellectual functioning has been demonstrated for children from "abnormal" populations such as institutionalized Ss and those referred for psychological evaluation because of emotional and, or, learning difficulties (1, 2, 3 ) . In contrast, a significant correlation was not obtained for a normal population ( 1 ) . The present study was designed to investigate the influence of the type of adjustment and age on the correlation of the Bender-Gestalt, as scored by the Koppitz Developmental Bender Scoring System, and intelligence, as measured by the WISC, for a Negro population. Ss ( N = 40) ranged in age from 6 yr. 7 mo. to 11 yr. 7 mo. (Grades 1 to 4 ) . Twenty Ss had been identified by teachers as those with learning difficulties, emotional problems, or both, while the remaining 20 Ss were chosen at random from the pool of students without school adjustment problems, except to control for grade and sex. Each S was tested individually by the same examiner. Acceptable reliability ( 9 4 and above) was demonstrated for scoring with the Koppitz system as well as with verbal sub-tests of the WISC. For all 40 Ss, the correlation of the Bender and the Full Scale IQ of the WISC is significantly different from zero (-.44; p < .01), though this is attributed mainly to the significant correlation between the Bender and the Performance IQ (-.72; p < .01). Other values are: r,, l,a = -.43, r,, a,, = -.46, r.,,, = -.63, rr.t = -.25 (ns = 20). Values of r for Bender scores and the Verbal IQs are insignificant for the total sample (-.14), as well as sub-groups (r,, = .32, r,, a,, = -.32, r,,.,,, = -.44, r,.f = .36; ns = 20). whereas the correlations of the Bender scores and the Performance IQs consistently are significant. The Bender-Performance IQ correlation of -.72 is significantly higher ( p < .05) than the mean (.47) of the 6 correlations, corrected for contamination, of individual performance sub-tests and the Performance score reported in the WISC manual for 74/2-yr.-old children. The Bender-performance IQ I is significantly higher ( p < .O5) in the present referral group ( 3 9 ) than in the normal group (-.58), but there is no significant difference between rs in our younger (-.66) and older (-.78) grades. The present data are compatible with results which led Koppitz to conclude that "the Bender Test measures many of the same functions as the WISC Performance Scale" (4, p. 48) but do not agree with the results obtained by Baer and Gale (1 ) with noninstitutional children. Race may contribute to this, but since the mean IQ of the normal Ss tested by Baer and Gale was 120.4, it is possible that a restricted range of IQ scores lowered the correlation to a non-significant level (-.23, with n = 6 9 ) . The present normal sample had a mean IQ of 97 (SD of 12.4).
Influence of dietary arachidonic acid on metabolism in vivo of 8 cis, 11 cis, 14-eicosatrienoic acid in humans

This study investigated the influence of dietary arachidonic acid (20∶4n-6) on Δ5 desaturation and incorporation of deuterium-labeled 8cis, 11cis, 14-eicosatrienoic acid (20∶3n-6) into human plasma lipids. Adult male subjects (n=4) were fed diets containing either 1.7 g/d (H120∶4 diet) or 0.21 g/d (LO20∶4 diet) of arachidonic acid for 50 d and then dosed with a mixture containing ethyl esters of 20∶3n-6[d4] and 18∶1n-9[d2]. A series of blood samples was sequentially drawn over a 72-h period, and methyl esters of plasma total lipid, triacylglycerol, phospholipids, and cholesteryl ester were analyzed by gas chromatography-mass spectrometry. Based on the concentration of 20∶3n-6[d4] in total plasma lipid, the estimated conversion of 20∶3n-6[d4] to 20∶4n-6[d4] was 17.7.±0.79% (HI20∶4 diet) and 2.13±1.44% (LO20∶4 diet). The concentrations of 20∶4n-6[d4] in total plasma lipids from subjects fed the HI20∶4 and LO20∶4 diets were 2.10±0.6 and 0.29±0.2 μmole/mL plasma/mmole of 20∶3n-6[d4] fed/kg of body weight. These data indicate that conversion of 20∶3n-6[d4] to 20∶4n-6[d4] was stimulated 7-8-fold by the HI20∶4 diet. Phospholipid acyltransferase was 2.5-fold more selective for 20∶3n-6[d4] than 18∶1n-9[d2], and lecithin:cholesterol acyltransferase was 2-fold more selective for 18∶1n-9[d2] than 20∶3n-6[d4]. These differences in selectivity were not significantly influenced by diet. Absorption of ethyl 20∶3n-6[d4] was about 33% less than ethyl 18∶1n-9[d2]. The sum of the n-6 retroconversion products from 20∶3n-6[d4] in total plasma lipids was about 2% of the total deuterated fatty acids. Neither absorption nor retroconversion appears to be influenced by diet.
Three sources of criterion variance: Static dimensionality, dynamic dimensionality, and individual dimensionality☆

Abstract This paper examines traditional usage of criterion measures and finds these traditional methods inadequate for retaining the lawful variance of the measures. Three sources of lawful variance are investigated, and evidence is found for the multidimensionality of each source: static dimensionality, dynamic dimensionality, and individual dimensionality. The dimensional complexity of the criteria coupled with traditional usage which discards lawful variance and the use of inappropriate predictors may contribute to the discouraging validities reported in the prediction of performance. The paper outlines a procedure which analyzes the sources of criterion variance and proposes two possible methods for criterion usage which may retain more of the lawful variance.
Changing Characteristics of Carotid Endarterectomy

We have noted significant differences in terms of our preoperative work-up, length of stay, morbidity, and mortality of patients undergoing carotid endarterectomy (CEA) from findings reported in large published randomized clinical trials. To further investigate these differences, we have reviewed our recent experience. CEA has proved to be the most effective approach to avert stokes caused by significant atherosclerotic disease of the carotid bifurcation. Between January 1, 1996 and December 31, 1998, 552 patients underwent CEA at our institution. Forty percent were performed in symptomatic patients with stenotic lesions >60% in diameter by duplex ultrasonography. The remainder were performed for asymptomatic lesions >60% in diameter. No patient underwent contrast angiography. Fifty-two percent of the patients were males. The mean age was 74 ± 8 years old. General anesthesia was used in 97% of the cases and regional block, in 3%. All patients underwent routine postoperative measurement of serum creatinine phosphokinase (CPK) isoenzymes. Patients were discharged when deemed clinically stable. The patients' follow-up visits at 1 week and at 3–5 months after the procedure (mean, 3.4 months) included a neurological exam and duplex exam. Patient results suggest that CEAs can be performed in the modern era without contrast arteriography. Most patients can be discharged on the first postoperative day. In addition, previously acceptable rates of postoperative morbidity and mortality should perhaps be revised to meet current standards. Contrary to the previous concept that most postoperative strokes are due to embolic phenomena, hyperperfusion syndrome played an increasingly important role in this review.