cssi/SciSciGPT-SciSciNet huggingface dataset:
Acute neonatal glucocorticoid exposure produces selective and rapid cerebellar neural progenitor cell apoptotic death

There has been a growing controversy regarding the continued use of glucocorticoid therapy to treat respiratory dysfunction associated with prematurity, as mounting clinical evidence has shown neonatal exposure produces permanent neuromotor and cognitive deficits. Here we report that, during a selective neonatal window of vulnerability, a single glucocorticoid injection in the mouse produces rapid and selective apoptotic cell death of the proliferating neural progenitor cells in the cerebellar external granule layer and permanent reductions in neuronal cell counts of their progeny, the cerebellar internal granule layer neurons. Our estimates suggest that this mouse window of vulnerability would correspond in the human to a period extending from approximately 20 weeks gestation to 6.5 weeks after birth. This death pathway is critically regulated by the proapoptotic Bcl-2 family member Puma and is independent of p53 expression. These rodent data indicate that there exists a previously unknown window of vulnerability during which a single glucocorticoid exposure at clinically relevant doses can produce neural progenitor cell apoptosis and permanent cerebellar pathology that may be responsible for some of the iatrogenically induced neurodevelopmental abnormalities seen in children exposed to this drug. This vulnerability may be related to the physiological role of glucocorticoids in regulating programmed cell death in the mammalian cerebellum.
Reaction of ozone with phospholipid vesicles and human erythrocyte ghosts

Abstract Phospholipid vesicles (unilamellar) and liposomes (multilamellar) made from egg phosphatidylcholine reacted similarly with ozone, producing hydrogen peroxide and malonaldehyde. On the basis of amount of ozone reacted, there was a 20% yield of hydrogen peroxide and 2.4% yield of malonaldehyde. The reactivity of the egg phosphatidylcholine membranes was a function of exposed membrane surface area. Large amounts of ozone caused no change in erythrocyte ghost phospholipid, fatty acid, or cholesterol composition. Thiobarbituric acid-positive material and conjugated dienes were present in very small quantities, suggesting some lipid oxidation which was below the limits of chromatographic detection. Ozone inhibited glyceraldehyde 3-phosphate dehydrogenase more than (Na + + K + ) adenosine triphosphate in exposed unsealed erythrocyte ghosts. The (Na + + K + ) adenosine triphosphatase activity sensitive to ozone was the ouabain-insensitive activity. Acetylcholinesterase activity was not significantly inhibited.
Solvent and frequency dependence of vibrational dephasing on femtosecond time-scales

The results of degenerate wavenumber third-order polarization (pump-probe) measurements of vibrational dephasing and relaxation in a variety of solvents are reported. The 20 fs duration pulses are sufficiently short to allow the preparation and detection of vibrational coherences (i.e. wavepackets) to 800 cm−1 oscillator wavenumber. The high quality of the pump-probe data permits the unique determination of eight underdamped modes for the cyanine dye under study. The relaxation of the underdamped modes does not show a significant solvent dependence. The relaxation mechanisms that give rise to loss of vibrational coherence and to the solvent-dependent relaxation of low-wavenumber (<100 cm−1) modes are discussed. The wavenumber dependence of the vibrational dephasing rate varies with a scaled exponential dependence exp( —ω/ω0), or equally well with the inverse square of the vibrational wavenumber. The exponential form would imply that vibrational dephasing occurs by population relaxation. The latter form, however, may imply higher order coupling between the bath and solute through the solute vibrational anharmonicity such that the off-diagonal contributions to the prepared wavepacket relax by pure dephasing. Exponentially decaying contributions to the pump—probe signal are found to arise from overdamped modes that are excited by the short laser pulses as opposed to a solvation response. The solvent-dependent relaxation of these overdamped modes is determined to be similar to diffusive unimolecular barrier crossing dynamics observed in dense media.
Expression and purification of soluble monomeric streptavidin in Escherichia coli

We recently reported the engineering of monomeric streptavidin (mSA) for use in monomeric detection of biotinylated ligands. Although mSA can be expressed functionally on the surface of mammalian cells and yeast, the molecule does not fold correctly when expressed in Escherichia coli. Refolding from inclusion bodies is cumbersome and yields a limited amount of purified protein. Improving the final yield should facilitate its use in biotechnology. We tested the expression and purification of mSA fused to GST, MBP, thioredoxin, and sumo tags to simplify its purification and improve the yield. The fusion proteins can be expressed solubly in E. coli and increase the yield by more than 20-fold. Unmodified mSA can be obtained by proteolytically removing the fusion tag. Purified mSA can be immobilized on a solid matrix to purify biotinylated ligands. Together, expressing mSA as a fusion with a solubilization tag vastly simplifies its preparation and increases its usability in biotechnology.
Catheter-directed thrombolysis reduced the postthrombotic syndrome in acute iliofemoral DVT

Source Citation Enden T, Haig Y, Klow NE, et al; CaVenT Study Group. Long-term outcome after additional catheter-directed thrombolysis versus standard treatment for acute iliofemoral deep vein thro...
Effect of hypophysectomy and growth hormone on estrogen-induced vitellogenesis in the freshwater turtle, Chrysemys picta.

Abstract Vitellogenesis was induced by multiple injections of estradiol-17β in male and female freshwater turtles, Chrysemys picta , and the rate of vitellogenesis was measured by the appearance of plasma 32 P-labeled phosphoprotein in plasma. This was linear for the first 10 hr post- 32 P injection and declined thereafter. The initial linear release was taken as a measure of the rate of synthesis of vitellogenin. This was significantly reduced by hypophysectomy in male and female turtles when compared to that of intact estrogen-treated controls. Ovine growth hormone injection (12 × 100 μg) in hypophysectomized turtles of both sexes restored the estrogen-induced vitellogenesis to a level comparable to that of intact animals. These data strongly suggest a role of the pituitary in regulating the estrogen sensitivity of the vitellogenic response.
Leveraging higher education for workforce development

Leveraging higher education resources to build a state's workforce takes dedicated commitments from business, education, and public policy leaders. Consortia can play an important role as facilitator and convener.
Thresholds for Activation of Rabbit Retinal Ganglion Cells with Relatively Large, Extracellular Microelectrodes

RESULTS. Both short-latency (SL; 3–5 ms) and long-latency (LL; 9 ms) responses were observed after electrical stimulation within the receptive field of an RGC. With short, 0.1-ms current pulses, the threshold current for the SL cell response was significantly lower than that for the LL cell response. With long (10- to 20-ms) pulses, the threshold currents for the SL and LL cell responses were very similar. The threshold current for the SL cell response increased more steeply than did the LL cell response when the electrode was displaced from the point of lowest electrical threshold, either above or along the surface of the retina. Stimulation of an RGC axon outside of the cell’s receptive field produced only an SL response. For 0.1-ms duration pulses, the threshold current for the axonal response was significantly higher than the threshold current for the SL cell response. At pulse durations 1 ms, the thresholds were very similar. CONCLUSIONS. RGC responses to electrical stimulation depend on the current pulse duration and location of the stimulating electrode. For an epiretinal prosthesis, short-duration current pulses may be preferable since they result in a more localized activation of the retina. (Invest Ophthalmol Vis Sci. 2005;46: 1486 –1496) DOI:10.1167/iovs.04-1018
Screening for PTSD among Somali adolescent refugees: Psychometric properties of the UCLA PTSD Index

This study presents the psychometric properties for the UCLA Posttraumatic Stress Disorder Index among a sample of Somali adolescents. Data were derived from a sample of English-speaking Somali adolescent refugees between the ages of 12 and 19 years (n = 76). The UCLA PTSD Index showed good reliability (Cronbach's α = .85). Convergent validity was assessed through bivariate correlations with the Depression Self Rating Scale (r = .72, p < .001) and the War Trauma Screening Scale (r = 59, p < .001). Results suggest that the UCLA PTSD Index may be a reliable and valid screening tool for PTSD symptoms for use with Somali adolescent refugees.
Optical effects of photochemically deposited contaminant films

ABSTRACT Two aromatic hydrocarbons, bibenzyl (BB) and dodecahydrotriphenylene (DTP) have been studied in anongoing contaminant effects measurement program. Photochemical deposition of these molecules did not proceed quickly under conditions which result in the deposition of dark, tenacious films from phthalate, siloxane, and alkene precursor molecules. Additional measurements show that DTP probably does not deposit photochemically at a substantial rate because the quantum yield for photodeposition is small, not that a DTPmolecule does not reside on the surface long enough to absorb light. The initial sticking coefficient of DTP appears to depend on surface temperature. Films of DTP scatter visible and near-ultraviolet light very efficiently, which is consistent with the observed heats of vaporization and desorption for this molecule. 1. INTRODUCTION AND SUMMARYIt has become well recognized that contaminant films, deposited either during ground operations or gradually on orbit, can have significant deleterious effects on the optical and thermal properties of spacecraft surfaces.
The type II insulin-like growth factor (IGF) receptor has low affinity for IGF-I analogs: pleiotypic actions of IGFs on myoblasts are apparently mediated by the type I receptor.

We have characterized binding and several actions of the somatomedins [insulin-like growth factors I and II (IGF-I and IGF-II)] on L6 myoblasts. Both IGF-I and IGF-II are potent stimulators of amino acid uptake, cell proliferation, and differentiation; they also suppress protein degradation in these cells. In all measurements, the relative potencies are IGFI > IGF-II > insulin. Two recombinant DNA-produced analogs of IGF-I, (Thr69)IGF-I and (N-Met)IGF-I, were as active as native IGF-I in all four assays. However, when 125I-labeled hormones were used for studies of binding to IGF receptors, there was a striking difference between the native and recombinant IGF-I molecules. Both were bound significantly by the type I receptor (a 350K molecule that is dissociated upon sulfhydryl reduction), but the recombinant analogs exhibited little cross-reactivity with the type II receptor (a 220K molecule that is not dissociated by reduction). Thus, the equal activity of native IGF-I and its recombinant DNA-produced ana...
Magnetic resonance investigation of blood flow after aortic valve bypass (apicoaortic conduit).

Background Aortic valve bypass (AVB, apicoaortic conduit) is an alternative to aortic valve replacement (AVR) for high-risk patients with aortic stenosis (AS). The redistribution of blood flow after AVB has been poorly characterized. In order to understand cardiovascular physiology after AVB, we performed cardiac magnetic resonance (CMR) imaging of AVB recipients. Methods Fifteen patients with symptomatic AS underwent beating-heart AVB. Electrocardiography-gated two-dimensional phase-contrast velocity mapping CMR imaging was conducted on each patient. Instantaneous flow was acquired at discrete intervals within the cardiac cycle and ventricular function and volumes were evaluated. Five age-matched patients without aortic valve disease served as controls. Results Conduit flow (as a percent of total cardiac output) was 65% ± 5%. Ejection fraction was unchanged compared with before AVB (50% ± 17% versus 57% ± 13%; p = 0.91). Ventricular volumes and cardiac indices were within normal limits and similar to those values in controls (cardiac index 2.9 ± 1.0 versus 2.3 L/min/m 2 ; p = 0.26; end-diastolic volume index 59 ± 17 mL versus 55 ± 20 mL; p = 0.66; end-systolic volume index, 25 ± 12 versus 25 ± 18 mL; p = 0.91; stroke volume index, 33 ± 11 versus 30 ± 6 mL; p = 0.57 for AVB and control patients, respectively). There was a small degree of retrograde blood flow in the descending aorta above the level of the conduit insertion (10% ± 8% of cardiac output). Conclusions Aortic valve bypass results in a predictable blood flow distribution between the native aorta and conduit and is associated with normal ventricular volumes and function.
Efficiency and cost trade-offs for designing module integrated converter photovoltaic systems

Photovoltaic (PV) systems are moving away from the traditional series-string PV structure and towards a module-integrated-converter (MIC) configuration for improved energy capture. A MIC approach trades off increased power production with increased cost and overhead power consumption. This research compares efficiency and cost of series-string, micro-converter, and micro-inverter PV system configurations. Analytical models for power production, cost, and cost per watt are developed for each configuration. Design choices such as the current sensor type, microcontroller, and maximum power point tracking (MPPT) algorithm affect power production and cost. Various design cases are explored to identify the number of MICs that minimize system cost per watt.
Parallel programming for multimedia applications

Computing capabilities are continuing to increase with the availability of multi core and many core processors. The wide availability of multi core processors has made parallel programming possible for end user applications running on desktops, workstations, and mobile devices. While parallel hardware has become common, software that exploits parallel capabilities is just beginning to take hold. Multimedia applications, with their data parallel nature and large computing requirements will benefit significantly from parallel programming. In this paper an overview of parallel programming is presented and languages and tools for parallel programming such as OpenMP and CUDA are introduced within the scope of multimedia applications.
Efficient high order positivity preserving DG-FEM methods for multi-dimensional Vlasov simulations of plasma

Summary form only given. Discontinuous Galerkin finite element methods (DG-FEM) are a powerful solution technique for nonlinear hyperbolic conservation laws, such as those that arise in the modeling of plasma. DG-FEM can be applied to achieve high-order spatial accuracy; however, one drawback of classical DG-FEM with explicit time-stepping is their poor CFL restriction compared to high-order finite difference or finite volume counterparts. In kinetic models of collisionless plasma, i.e. kinetic Vlasov models, this small time step problem is further exacerbated due to the possibility that some particles in the system may travel at moderate to large velocities. In this work, we extend our single dimension, 1D-1V semi-Lagrangian discontinuous Galerkin (SLDG) method1 to 2D-2V, two dimensions for configuration space, and two dimensions for velocity space. The DG representation allows us to capture complicated geometries in configuration space through the use of unstructured grids. Our method uses operator splitting techniques that enable us to apply different time stepping options in each direction. For velocity space, we use the semi-Lagrangian DG method on a structured grid that removes CFL limitations on the electric field. For configuration space, we apply explicit Runge-Kutta time stepping on unstructured grids. In order to mitigate restrictive CFL conditions, each sub-problem is sub-cycled according to a local velocity. Due to the fact that the proposed scheme is mesh-based and high-order accurate, we can compute solutions with much less statistical noise than what is found in traditional particle-in-cell (PIC) solutions of comparable resolution. We present simulation results for the formation of a plasma sheath in a collisionless plasma. We start with a 1D problem, and then demonstrate how the multi-D extension performs on a radially symmetric cylinder. We argue that our high-order mesh based method allows us to simultaneously produce accurate results for the plasma sheath near the wall as well as the quasi-neutral region.
Developing an Online Information System Prototype for Global Satellite Precipitation Algorithm Validation and Intercomparison

Abstract Over the decades, significant progress has been made in satellite precipitation product development. In particular, temporal resolution and timely availability have been improved by blended techniques. The resulting products, including near-real-time precipitation products, are widely used in various research and applications. However, the lack of support for user-defined areas or points of interest poses a major obstacle to quickly gaining knowledge of product quality and behavior on a local or regional scale. Current online operational intercomparison and validation services have not addressed this issue adequately. This paper describes an ongoing work to develop an online information system prototype for global satellite precipitation algorithm validation and intercomparison, to overcome current shortcomings by providing dynamic and customized information to users on the expected bias and accuracy of the products, and to give algorithm developers a better understanding of the strengths and wea...
On The Time Scale of Internal Energy Relaxation of AP-MALDI and nano-ESI Ions in a Quadrupole Ion Trap

Recently reported results (Konn et al. [14]) on the collisional cooling of atmospheric pressure matrix assisted laser desorption ionization (AP-MALDI) and nano-electrospray ionization (nano-ESI) generated ions in a quadrupole ion trap mass spectrometer (QITMS) are inconsistent with measured collisional cooling rates. The work reported here presents a re-examination of those previous results. Collision induced dissociation (CID) has been used to probe various properties of ions contained in a QITMS. It is shown experimentally that when trapping large numbers of ions, an effective dc trapping voltage is induced that varies with changes in the size of the ion cloud. A decrease in the resonant frequency for maximum CID efficiency is observed as the cool time between parent ion isolation and CID is increased. Ion trajectories in a QITMS are simulated to demonstrate how ion density changes over the course of parent ion isolation. The effect of space charge on ion motion is simulated, and Fourier transformations of ion axial motion plus simple calculations corroborate the experimentally observed transient frequency shifts. The relative stability of ions formed by AP-MALDI and nano-ESI is compared under low charge density conditions. These data show that the ions have reached equilibrium internal energy and, thus, that differences in dissociation onsets and “50% fragmentation efficiency points” between the ionization mechanisms are due to the formation of distinct ion conformations as previously shown in reference [28]. The conclusions of Konn et al. [14] are based on invalid experimental procedures as well as inappropriate comparisons of QITMS data to low-pressure FT-ICR data.
Effects of Epidermal Hydration on Skin Potential Responses and Levels

Hydration of the epidermis promotes swelling of the stratum corneum, mechanical blockages of the sweat gland pore in the epidermis, and subsequent inhibition of surface sweating. If sweating continues in combination with poral closure, the resultant increase in hydrostatic pressure in the sweat duct is likely to alter the permeability of the sweat gland membrane. The experiments reported here investigated the significance of these effects for negative and positive skin potential responses (SPRs), and for the prestimulus levels associated with these responses. Hydration was found to virtually eliminate positive SPRs and to greatly reduce the prestimulus levels. A similar, though somewhat less drastic, effect was found for negative SPRs and prestimulus level. The hydration produced by a standard electrolyte (0.5% KCl in an agar jelly medium) appears to show a curvilinear time course with a rapid initial phase followed by slowly increasing hydration throughout a 20-min period. The results were attributed to poral closure and to increased conductance through the epidermal pathway and were discussed in connection with recently suggested models of the electrodermal effector system.
Adenosine Receptor Mediates Motility in Human Melanoma Cells

Cell motility is an essential component of tumor progression and metastasis. A number of factors, both autocrine and paracrine, have been found to influence cell motility. In the present study, adenosine and adenine nucleotides directly stimulated chemotaxis of A2058 melanoma cells in the absence of exogenous factors. Three adenosine receptor agonists stimulated motility in the melanoma cells and two adenosine receptor antagonists strongly inhibited the chemotactic response to both adenosine and AMP. The chemotactic stimulation by adenosine and AMP was pertussis toxin sensitive. Otherwise unresponsive Chinese hamster ovary cells which were transfected with the adenosine A1 receptor cDNA acquired the direct, pertussis toxin sensitive, chemotactic response to adenosine, and this response was inhibited by adenosine receptor antagonists. These findings demonstrate that adenosine and adenine nucleotides are capable of stimulating chemotaxis of tumor cells mediated through an adenosine receptor, probably of the A1 subtype. The possibility of antimetastatic therapies based on inhibition of adenosine receptor activity is raised.
The Mechanism of Locomotion of Flagellates. II. Function of the Mastigonemes of Ochromonas

SYNOPSIS. Mastigonemes occur on flagella of many species of Protozoa, but the only function so far proposed for the mastigonemes is to increase the effective surface of the flagellum. Locomotion of Ochromonas malhamensis, O. danica, and an unidentified marine chrysomonad was examined by means of high speed microcinematography up to 600 pictures per second. In addition, analyses were performed on the movement of the organism in a suspension of polystyrene spheres (1.17 μ in diameter). The films clearly show that the organisms move by means of a planar sine wave in the long anteriorly-directed flagellum. The wave starts at the basal end of the flagellum and progresses distally. It is apparent that the organisms are pulled forward by the action of the long flagellum, and that the flagellum does not push backward as would ordinarily be expected with a forwardly-directed sine wave. It is well known that flagellar sine waves usually start at the base, move distally, and produce a push toward the point of attachment. It also is known (2) that in Mastigamoeba a helical wave may start at the tip, progress proximally toward the base, and pull the organism. However, in the present organisms the wave begins at the base, moves distally (i.e., forward), and pulls the organism. The flagellum is a true tractellum. The theoretical calculations of Taylor (1952, Proc. Roy. Soc., 214A, 158) show that if a thin cylinder, undergoing sinuous movements produced by a traveling sine wave of active bending, has a roughness of surface which is sufficiently great and has a certain directional character, propulsion may be achieved in the direction opposite to that expected of a smooth cylinder bending in exactly the same manner. It is known that the long flagellum of the chrysomonads is pantonematic, i.e., has numerous stiff lateral mastigonemes on at least two and probably all sides. It is proposed that one function of these mastigonemes is to provide a roughness of surface which brings about this type of reversal.
Exploring Leptin Antagonism in Ophthalmic Cell Models

Background Emerging evidence suggests that angiogenic and pro-inflammatory cytokine leptin might be implicated in ocular neovascularization. However, the potential of inhibiting leptin function in ophthalmic cells has never been explored. Here we assessed mitogenic, angiogenic, and signaling leptin activities in retinal and corneal endothelial cells and examined the capability of a specific leptin receptor (ObR) antagonist, Allo-aca, to inhibit these functions. Methods and Results The experiments were carried out in monkey retinal (RF/6A) and bovine corneal (BCE) endothelial cells. Leptin at 50-250 ng/mL stimulated the growth of both cell lines in a dose-dependent manner. The maximal mitogenic response (35±7 and 27±3% in RF6A and BCE cells, respectively) was noted at 24 h of 250 ng/mL leptin treatments. Leptin-dependent proliferation was reduced to base levels with 10 and 100 nM Allo-aca in BCE and RF6A cells, respectively. In both cell lines, leptin promoted angiogenic responses, with the maximal increase in tube formation (163±10 and 133±8% in RF6A and BCE cultures, respectively) observed under a 250 ng/mL leptin treatment for 3 h. Furthermore, in both cell lines 250 ng/mL leptin modulated the activity or expression of several signaling molecules involved in proliferation, inflammatory activity and angiogenesis, such as STAT3, Akt, and ERK1/2, COX2, and NFκB. In both cell lines, leptin-induced angiogenic and signaling responses were significantly inhibited with 100 nM Allo-aca. We also found that leptin increased its own mRNA and protein expression in both cell lines, and this autocrine effect was abolished by 100-250 nM Allo-aca. Conclusions Our data provide new insights into the role of leptin in ocular endothelial cells and represent the first original report on targeting ObR in ophthalmic cell models.
Stereotaxic atlas of the trigeminal ganglion in rat, cat, and monkey

Abstract Stereotaxic maps of the trigeminal ganglion of rat, cat, and monkey are presented. Each ganglion drawing is a composite composed from means of coordinates from several ganglions sampled. Depth coordinates are supplied in relation to both the dorsal surface of each ganglion and the cranial bone directly underlying the ganglion.
Equilibrium mechanisms of length regulation in linear protein aggregates

Statistical thermodynamic theories have been developed in order to explore the consequences of two prominent models of length regulation in linear protein aggregates: the length-determining factor model and the cumulated strain model. In the former, the possibility that the final subunit is bound with extra stability has been incorporated. Calculations explore the dependence of the sharpness of the onset of extensive polymerization, and the breadth, shape, and most probable value of the distribution as functions of concentrations of template and polymerizing subunit, of subunit association constant, of the strain free energy, and of the maximum length and extra stability of the last subunit in the length-determining factor model. Numerical calculations are made with particular reference to the parameters of bacteriophage T4 tail-core polymerization. Both models predict suitably narrow length distributions with plausible values of the thermodynamic parameters. The length-determining factor model may exhibit highly cooperative behaviour, with either fully polymerized or very short aggregates being observed as the product K[C] of association constant and free monomer constant is varied. This cooperativity is accentuated as binding of the final subunit becomes more stable. Species of intermediate length will be observable only if the length-determining factor is shortened. In the cumulated strain model, if K[C] is lowered at constant strain free energy per subunit, shorter aggregates will be observed; but increasing K[C] will not yield appreciably longer polymers. As [C] is lowered, the distribution will remain narrow.
Initial Roentgenographic Manifestations of Pulmonary Mycobacterium Tuberculosis, M Kansasii, and M Intracellularis Infections

The initial radiographic features of 188 patients with pulmonary infections due to Mycobacterium tuberculosis were compared to 184 patients with M kansasii and 100 patients with M intracellularis infections. The patients were all from the University of Texas Health Center at Tyler, all had at least two positive sputum cultures and no other potential pathogen, and none had a past medical history of any type of tuberculosis. The comparison showed that all three organisms have a strong tendency to produce cavitary infiltrates in the posterior portions of the upper lobes. No distinctive or pathognomonic feature could be found. The atypical organisms were more likely to produce thin-walled cavities and far advanced unilateral disease, but both of these patterns also occurred with M tuberculosis. Endobronchial spread and volume loss were common in all three diseases. The only definite difference seems to be the absence of a primary or juvenile form of atypical tuberculosis and a much greater incidence of empyema and postprimary pleural effusions with M tuberculosis. In an individual case, the roentgenographic manifestations of the three diseases are indistinguishable.
Differential effects of past climate warming on mountain and flatland species distributions: a multispecies North American mammal assessment

Aim The magnitude of predicted range shifts during climate change is likely to be different for species living in mountainous environments compared with those living in flatland environments. The southern edges of ranges in mountain species may not shift northwards during warming as populations instead migrate up available elevational gradients; overall latitudinal range appears therefore to expand. In contrast, flatland species should shift range centroids northwards but not expand or contract their latitudinal range extent. These hypotheses were tested utilizing Late Pleistocene and modern occurrence data. Location North America. Methods The location and elevation of modern and Late Pleistocene species occurrences were collected from data bases for 26 species living in mountain or flatland environments. Regressions of elevation change over latitude, and southern and northern range edges were calculated for each species for modern and fossil data sets. A combination of regressions and anovas were used to test whether flatland species shift range edges and latitudinal extents more than mountain species do. Results Flatland species had significantly larger northward shifts at southern range edges than did mountain-dwelling species from the Late Pleistocene to the present. There was also a significant negative correlation between the amount of change in the latitude of the southern edge of the range and the amount of elevational shifting from the Late Pleistocene to the present. Although significant, only c. 25% of the variance could be explained by this relationship. In addition, there was a weak indication that overall range expansion was less in flatland-dwelling than in mountain-dwelling species. Main conclusions The approach used here was to examine past species’ range responses to warming that occurred after the last ice ages as a means to better predict potential future responses to continued warming. The results confirm predictions of differential southern edge and overall range shifts for species occupying mountain and flatland regions in North America. The findings may be broadly applicable in other regions, thus allowing better modelling of future range and distribution related responses.
A method of estimating monthly average solar radiation on shaded receivers

Abstract The geometry of vertical solar radiation receivers shaded by overhangs is described. The instantaneous mean solar radiation on a shaded receiver is defined leading to a method of estimating H s , the monthly average daily radiation on a shaded receiver. Values of the monthly average beam irradiated fraction of the receiver area, f i , are presented in a series of figures. The effects of overhang extension and receiver azimuth on H s are considered. Example calculations are presented and the overall effect of an overhang as a shading device is discussed.
Hydroxyapatite: mechanism of formation and properties.

Hydroxyapatite (HA) was prepared by stirring amorphous calcium phosphate (ACP), which contained occluded Cl− as a tracer ion, in distilled water buffered to pH 7.4 by tris-HCl at 25, 37, 60, 80 and 100°. HA made in this manner contained from less than 1% (25°) to 11% (100°) of the amount originally occluded in the precursor ACP. These results suggest that the principal mechanism of conversion is a series of solution- mediated rate processes that enable ions to move away from the dissolving ACP before the onset of HA nucleation.In situ ACP rearrangement does not provide for ion escape and is probably not involved in the conversion. The infrared spectra of high specific surface HA prepared at 25° and 37° showed no OH stretching or OH librational bands, while the lower specific surface HA (60°, 80°, 100°) displayed sharp bands of these vibrational modes. This effect is attributed to hydrogen bonding of structural OH groups on the surface on HA crystals with the strongly adsorbed water monolayer present on HA. As in other systems, hydrogen bond formation probably smears out the OH absorption bands so that only OH groups in the crystal interior yield sharp, unperturbed OH bands. As the HA specific surface decreases, the smearing effect becomes minimal due to a concomitant decrease in the percentage of surface-located OH groups. This may explain the observed absence of OH vibrational modes in the infrared spectrum of bone mineral, since bone apatite has a specific surface comparable to that of HA synthesized at 25° and 37°.
Which Aspects of ADHD Are Associated with Tobacco Use in Early Adolescence

Several studies have found a relationship between attention-deficit hyperactivity disorder (ADHD) and substance use, primarily in the context of co-occurring conduct disorder (CD). However, very few have examined the associations between the individual dimensions of ADHD (hyperactivity-impulsivity and inattention) and substance use, even though these dimensions reflect distinct symptom groupings, both by clinical definition (DSM-IV, American Psychiatric Association, 1994) and through empirical demonstration (Lahey et al., 1988; McBurnett et al., 1999). This longitudinal study examines the relationship between dimensions of ADHD (as described by DSM) and substance use, accounting for other psychopathology and factors potentially related to substance use. Participants were 177 clinic-referred boys (initially between ages 7 and 12) followed up over nine annual phases until all participants had reached age 15. Annual assessment included structured clinical interviews with parent and child and self-report questionnaires of substance use, as well as questionnaires related to family factors and parenting behaviors. Seventy-eight per cent of participants reported use of tobacco, alcohol, marijuana, or other illicit drugs during adolescence, with 51% reporting any tobacco use. The inclusion of CD rendered all bivariate relationships with the full diagnosis of ADHD nonsignificant. However, adolescent inattention, considered independently, was associated with a 2‐2 times greater risk for concurrent tobacco use, even after controlling for CD. Even when other factors, selected based on their associations with tobacco use in adolescence, were included in a regression model (concurrent adolescent CD odds ratio [OR] fl 6‐08), duration of tobacco use by age 12 (OR fl 5‐11), poor parental communication in childhood (OR fl 2‐9), African-American ethnicity (inversely predictive; OR fl 0‐15), inattention (OR fl 2‐3) remained significantly associated with tobacco use in early adolescence. These findings highlight the importance of considering the risks for comorbid substance use separately by individual dimensions of ADHD.
Adaptations in muscular activation of the knee extensor muscles with strength training in young and older adults

The purpose of this study was to compare the extent of muscular activation during maximal voluntary knee extension contractions in old and young individuals and to examine the effects of resistance training on muscular activation in each group. The interpolated twitch technique was used to estimate muscular activation during two pre-training baseline tests, and after two and six weeks of resistance training. Throughout the study, the older group was 30% less strong than the young group (p=0.02). The training protocol was effective in both groups with overall isometric strength gains of 30 and 36% in the older (p=0.01) and young (p<0.01) groups, respectively. 10-RM training loads increased by 66% in the old group (p<0.01) and by 77% in the young group (p<0.01) throughout training. At the first baseline test, a 2% difference in muscular activation between groups (p=0.3) did not explain the large disparity in strength. Muscular activation increased by 2% in both groups throughout training (p<0.01). Despite considerably less muscular strength in the older group, muscular activation was greater than 95% of maximum and appears to be equal in both young and older individuals. Both groups demonstrated similar but small increases in muscular activation throughout training.
MORPHOLOGY AND DISTRIBUTION OF NUCLEI DURING DEVELOPMENT IN CYMOPOLIA BARBATA (CHLOROPHYCOPHYTA, DASYCLADALES)1

The morphology and distribution of a variety of types of nucleus in the apex, in young and mature gametangia, and in older regions of the Cymopolia cell were studied by light and electron microscopy. Spherical and convoluted nuclei 2–7μm in diameter were observed in apical regions of the vegetative siphon. Nuclei 4 μm in diameter were present in the young primary laterals and in developing gametangia. A single characteristic nucleus migrates from the siphon into the primary lateral of the second basipetal whorl. It is further transported into one of several possible secondary laterals and determines the development of gametangia which become multinucleate in the fourth or fifth whorls. Nuclei are characterized by size, shape, nucleolar morphology, nucleoplasmic inclusions and the ultrastructure of the perinuclear cytoplasm. Although no “primary nucleus” characteristic of the uninucleate genera, Acetabularia and Batophora was observed, some nuclei of Cymopolia have features in common with secondary nuclei of these genera.
Prediction of end-bearing capacity of rock-socketed shafts considering rock quality designation (RQD)

Existing empirical methods for determining the end-bearing capacity, qmax, use empirical relations between qmax and the unconfined compressive strength of intact rock, σc. As rock-socketed shafts a...
Dependence of Drosophila wing imaginal disc cytonemes on Decapentaplegic

The anterior/posterior (A/P) and dorsal/ventral (D/V) compartment borders that subdivide the wing imaginal discs of Drosophila third instar larvae are each associated with a developmental organizer. Decapentaplegic (Dpp), a member of the transforming growth factor-beta (TGF-beta) superfamily, embodies the activity of the A/P organizer. It is produced at the A/P organizer and distributes in a gradient of decreasing concentration to regulate target genes, functioning non-autonomously to regulate growth and patterning of both the anterior and posterior compartments. Wingless (Wg) is produced at the D/V organizer and embodies its activity. The mechanisms that distribute Dpp and Wg are not known, but proposed mechanisms include extracellular diffusion, successive transfers between neighbouring cells, vesicle-mediated movement, and direct transfer via cytonemes. Cytonemes are actin-based filopodial extensions that have been found to orient towards the A/P organizer from outlying cells. Here we show that in the wing disc, cytonemes orient towards both the A/P and D/V organizers, and that their presence and orientation correlates with Dpp signalling. We also show that the Dpp receptor, Thickveins (Tkv), is present in punctae that move along cytonemes. These observations are consistent with a role for cytonemes in signal transduction.
Therapeutic alternatives in the treatment of life-threatening vasoformative tumors.

Although classified as benign vasoformative tumors, a small percentage of hemangiomas and lymphangiomas follow an unpredictable biologic course. Rapid growth and the involvement of vital structures can lead to a variety of life-threatening complications. Aggressive treatment using a variety of therapeutic modalities is required in these situations. Our clinical experience with three children with life-threatening benign vasoformative tumors is presented, followed by a discussion of the diagnostic and therapeutic considerations bearing on such aggressive lesions.
Thin layer chromatographic analyses of amino acids in Echinostoma revolutum (Trematoda) adults

Abstract Bailey R. S. Jr. and Fried B. 1977. Thin layer Chromatographic analyses of amino acids in Echinostoma revolutum (Trematoda) adults. International Journal for Parasitology 7: 497–499. Thin layer Chromatographic analyses were made on free pool amino acids and those obtained from the incubate fluid of Echinostoma revolutum adults maintained in a non-nutrient salt solution. The major free pool amino acids detected were alanine, proline, serine and methionine. Alpha-amino- n -butyric acid was also tentatively identified. Amino acids detected in the incubate fluid were leucine-isoleucine, valine, methionine, tyrosine, proline, alanine, glutamic acid, serine, arginine, and aplha-amino- n -butyric acid was also tentatively identified. Amino acids presumably isolated from either worm egesta or the protonephridial system were qualitively similar to those obtained from worm incubate fluid.
A comparative study of three methods for intracellular loading of the calcium indicator aequorin in ferret papillary muscles.

We compared the results of loading the bioluminescent Ca++ indicator aequorin by standard microinjection techniques to those obtained with two new chemical approaches to loading that utilize low concentrations of Ca++ chelator; i.e., 1) Immersion and 2) Macroinjection. After loading with the immersion and macroinjection methods, twitch tension returned to pre-load values indicating lack of damage to the muscles. The aequorin signals obtained with all three methods were similar and converted to similar quantitative values for [Ca++]i. Our data suggest that chemical loading (in particular macroinjection) may be preferable to microinjection, particularly in muscles with increased connective tissue content.
Electronic drop sensing in microfluidic devices: automated operation of a nanoliter viscometer

We describe three droplet sensing techniques: a digital electrode, an analog electrode, and a thermal method. All three techniques use a single layer of metal lines that is easy to microfabricate and an electronic signal can be produced using low DC voltages. While the electrode methods utilize changes in electrical conductivity when the air/liquid interface of the droplet passes over a pair of electrodes, the thermal method is based on convective heat loss from a locally heated region. For the electrode method, the analog technique is able to detect 25 nL droplets while the digital technique is capable of detecting droplets as small as 100 pL. For thermal sensing, temperature profiles in the range of 36 °C and higher were used. Finally, we have used the digital electrode method and an array of electrodes located at preset distances to automate the operation of a previously described microfluidic viscometer. The viscometer is completely controlled by a laptop computer, and the total time for operation including setup, calibration, sample addition and viscosity calculation is approximately 4 minutes.
On the footsteps of Triadin and its role in skeletal muscle.

Calcium is a crucial element for striated muscle function. As such, myoplasmic free Ca2+ concentration is delicately regulated through the concerted action of multiple Ca2+ pathways that relay excitation of the plasma membrane to the intracellular contractile machinery. In skeletal muscle, one of these major Ca2+ pathways is Ca2+ release from intracellular Ca2+ stores through type-1 ryanodine receptor/Ca2+ release channels (RyR1), which positions RyR1 in a strategic cross point to regulate Ca2+ homeostasis. This major Ca2+ traffic point appears to be highly sensitive to the intracellular environment, which senses through a plethora of chemical and protein-protein interactions. Among these modulators, perhaps one of the most elusive is Triadin, a muscle-specific protein that is involved in many crucial aspect of muscle function. This family of proteins mediates complex interactions with various Ca2+ modulators and seems poised to be a relevant modulator of Ca2+ signaling in cardiac and skeletal muscles. The purpose of this review is to examine the most recent evidence and current understanding of the role of Triadin in muscle function, in general, with particular emphasis on its contribution to Ca2+ homeostasis.
DIPOLE THEORY IN ELECTROCARDIOGRAPHY.

Abstract The equivalent cardiac generator consists of fictitious sources in an appropriate volume conductor which simulate all surface electrocardiograms on a given subject. It is convenient to consider the equivalent generator concept since it is not possible to determine the actual internal sources from surface measurements. Theory and research have been dominated by the idea of using the dipole as an equivalent source. The dipole, for example, forms the basis of vectorcardiography. Evidence gathered to date indicates that the dipole is inadequate on physical grounds, if not current clinical ones. Alternative approaches include the use of a multiple dipole source or a multipole source. The multipole source is appealing because of the evidence that the dipole approximation is less adequate for persons with known heart disease than it is for normal individuals.
Coplanar waveguide feed for microstrip patch antennas

A coplanar waveguide (CPW) loop is shown to be an effective low VSWR feed for microstrip antennas. The low VSWR transition between the CPW and the antenna is obtained without the use of a matching circuit, and it is relatively insensitive to the position of the antenna and the feed.
Handling and Environmental Effects on Viability of Mechanically Dispensed Green Lacewing Eggs

Abstract Mechanical distribution and release of commercially produced green lacewing eggs, Chrysoperla rufilabris Burmeister (Neuroptera, Chrysopidae), was simulated by dispensing an egg/vermiculite mixture through a prototype mechanical distributor. The distributor was subjected to vibration similar to that measured on a tractor traveling in a field. Lacewing egg survival was determined following passage through the vibrating distributor and exposure to environmental conditions that simulated greenhouse and vineyard canopy conditions. The hatching rate from all treatments was no different from the hatching rate from untreated controls. Consistency of egg distribution, as measured by rate of egg release (the product of concentration of eggs in vermiculite carrier, eggs/ml, and discharge rate of carrier, ml/min) was uniform over 60 min of vibration and release. The results establish the feasibility of mechanical distribution of viable green lacewing eggs.