cssi/SciSciGPT-SciSciNet huggingface dataset:
A study of the crustacean axon repetitive response. II. The effect of cations, sodium, calcium (magnesium), potassium and hydrogen (pH) in the external medium.

The effects of sodium, calcium, potassium (magnesium), potassium, and hydrogen (pH) ion concentration in the external medium on the repetitive response and the transmembrane electrical parameters of the crustacean axon have been investigated. (1) The action potential is reduced with decrease in sodium ion concentration, the relationship is linear if the spike voltage is plotted against the log (Na0). The action potential amplitude does not increase significantly, above 135 mv, attained at Na0 = 452 mM, if Na0 is increased. (2) The repetitive response and oscillatory activity in general disappears as the sodium concentration is reduced to less than 150 mM. (3) The critical firing level increases with decrease in sodium, the relationship linear with respect to log (Nao). (4) The positive after potential amplitude is not affected by the sodium concentration. (5) The membrane resistance is not affected by sodium concentration. (6) Calcium lack results in decreased critical firing level and spontaneous firing, followed by a total and irreversible loss of excitability. The membrane resistance is markedly decreased. Polarizing current, if applied early after the onset of the calcium lack effect, may restore, at least partially, the excitability phenomenon. (7) Calcium excess increases membrane resistance, depresses excitability. Calcium concentration of 150 mM abolishes the repetitive response. (8) There is a 3.3+: 1 ratio Na:Ca for threshold level of repetitive response. Lower ratio figures, by reducing Na or increasing Ca or both, eliminates repetition. Increasing the ratio figure by increasing sodium or decreasing calcium or both augments oscillatory activity. This ratio is constant between the limits 400 mM Na:125, Ca to 90 mM Na:25 mM Ca. (9) Magnesium may substitute for calcium, the Na:Mg ratio for repetitive response threshold is 3.3:2. (10) Repetitive firing may be elicited over a wide range of pH values 4.2–10.5; membrane potential and resistance values decline invariably at pH values above 9.5 and below 4.5. (11) Repetitive firing is enhanced by increasing pH values, depressed by reducing pH values. (12) Effect of excess potassium produces depolarization, reduced membrane resistance, inactivation and abolition of repetitive firing, may be relieved by applied hyperpolarization. (13) Potassium lack results in membrane potential and resistance irreversible decline, permanent inactivation, total loss of excitability. Partial restoration by strong hyperpolarization if applied before effect is complete. Potassium replacement in solution only slows or temporarily arrests the overall membrane deterioration. (14) Conclusions - sodium controls spike, potassium controls after potential, calcium (magnesium) controls membrane permeability, pH controls amount of available ionized calcium. Repetitive firing requires proper ratio 3.3/1 of (Nao)/(Ca0), pH above 7.6 and potassium at 15 mM in solution.
Modeling of sensor fidelity

The sensor response of a piezoelectric transducer embedded in a fluid loaded structure is modeled using a hybrid numerical approach. The structure is excited by an obliquely incident acoustic wave. Finite element modeling in the structure and fluid surrounding the transducer region is used and a plane wave representation is exploited to match the displacement field at the mathematical boundary. On this boundary, continuity of field derivatives is enforced by using a penalty factor. Numerical results are presented for the sensor response in different host materials piezoelectric sensor materials. It is found that the sensor at that location is not only non-intrusive but also sensitive to the characteristic of the structure.
QTLs for Energy-Related Traits in a Sweet × Grain Sorghum [Sorghum bicolor (L.)Moench] Mapping Population

To meet anticipated markets for sweet sorghum production, the development of sweet sorghum hybrids is underway. As this development is in its infancy, genetic markers will be very useful to define the genetic basis of sugar yield components and reduce the time required to deliver new hybrids to market. The purpose of this research was to characterize genetic components that influence sweet sorghum productivity and agronomics. A grain × sweet sorghum mapping population was evaluated for 16 phenotypic traits across four environments. 185 F3 derived F4 (F3:4) lines were derived from the parents ‘BTx3197’ and ‘Rio’, which are 9 dry-stalked grain and juicy-stalked sweet sorghums, respectively. A genetic map was constructed with 381 single nucleotide polymorphisms (SNPs) and quantitative trait locus (QTL) analysis was performed. A major and previously reported QTL for soluble solids was identified on chromosome 3, but in contrast to previous studies, this QTL co-localized with other QTLs that had negative influences on desirable traits. Therefore, selection for this QTL may not be advantageous. A limited number of QTLs for percent moisture were found, and results indicated that the dry-stalk phenotype does not affect moisture content as measured in this study. Thus, breeding for moisture content will be more challenging than previously expected. The absence of dominance effects for the brix trait indicated that brix must be high in both parents to produce high brix in hybrids.
Membrane dynamics of differentiating cultured embryonic chick skeletal muscle cells by fluorescence microscopy techniques

Changes in membrane fluidity during myogenesis have been studied by fluorescence microscopy of individual cells growing in monolayer cultures of embryonic chick skeletal muscle cells. Membrane fluidity was determined by the techniques of fluorescence photobleaching recovery (FPR), with the use of a lipid-soluble carbocyanine dye, and by fluorescence depolarization (FD), with perylene used as the lipid probe. The fluidity of myoblast plasma membranes, as determined from FPR measurements in membrane areas above nuclei, increased during the period of myoblast fusion and then returned to its initial level. The membrane fluidity of fibroblasts, also found in these primary cultures, remained constant. The fluidity in specific regions along the length of the myoblast membrane was studied by FD, and it was observed that the extended arms of the myoblast have the highest fluidity on the cell and that the tips at the ends of the arms had the lowest fluidity. However, since the perylene probe used in the FD experiments appeared to label cytoplasmic components, changes in fluidity measured with this probe reflect changes in membrane fluidity as well as in cytoplasmic fluidity. The relative change in each of these compartments cannot yet be ascertained. Tips have specialized surface structures, filopodia and lamellipodia, which may be accompanied by a more immobile membrane as well as a more rigid cytoplasm. Rounded cells, which may also have a more convoluted surface structure, show a lower apparent membrane fluidity than extended cells.
NASA/GSFC program in direct detection optical communications for intersatellite links

NASA-Goddard has undertaken the development of direct-detection optical communications for space applications at the Gbps data rate channel capability level. The primary challenges to optical communications designers lie in the development of reliable optical power sources, as well as of high performance pointing/acquisition/tracking systems required by the narrow widths of the transmitted optical beams. GaAlAs diodes and their arrays are currently the most attractive technology for optical transmitters; pioneering work has also been conducted on dichroic and grating techniques for combining the power of several laser diodes. Attention is given to the performance obtained for an optical link acquisition and submicroradian tracking/pointing system.
Conventions and workflows for using Situs

Situs is a modular program package for the multi-scale modeling of atomic resolution structures and low-resolution biophysical data from electron microscopy, tomography or small-angle X-ray scattering. This article provides an overview of recent developments in the Situs package, with an emphasis on workflows and conventions that are important for practical applications. The modular design of the programs facilitates scripting in the bash shell that allows specific programs to be combined in creative ways that go beyond the original intent of the developers. Several scripting-enabled functionalities, such as flexible transformations of data type, the use of symmetry constraints or the creation of two-dimensional projection images, are described. The processing of low-resolution biophysical maps in such workflows follows not only first principles but often relies on implicit conventions. Situs conventions related to map formats, resolution, correlation functions and feature detection are reviewed and summarized. The compatibility of the Situs workflow with CCP4 conventions and programs is discussed.
Special cases of diffusion from a sessile droplet through a membrane

Donnees sur 2 cas limites d'etalement des gouttelettes d'un aerosol, dans lesquels le probleme peut etre resolu avec exactitude avec certaines hypotheses sur la solubilite du compose dans la membrane
Molecular mechanisms of intracellular calcium excitability in X. laevis oocytes

Abstract Following receptor activation in Xenopus oocytes, spiral waves of intracellular Ca 2+ release were observed. We have identified key molecular elements in the pathway that give rise to Ca 2+ excitability. The patterns of Ca 2+ release produced by GTP-γ-S and by inositol 1,4,5-trisphosphate (IP 3 ) are indistinguishable from receptor-induced Ca 2+ patterns. The regenerative Ca 2+ activity is critically dependent on the presence of IP 3 and on the concentration of intracellular Ca 2+ , but is independent of extracellular Ca 2+ . Broad regions of the intracellular milieu can be synchronously excited to initiate Ca 2+ waves and produce pulsating foci of Ca 2+ release. By testing the temperature dependence of wavefront propagation, we provide evidence for an underlying process limited by diffusion, consistent with the elementary theory of excitable media. We propose a model for intracellular Ca 2+ signaling in which wave propagation is controlled by IP 3 -mediated Ca 2+ release from internal stores, but is modulated by the cytoplasmic concentration and diffusion of Ca 2+ .
Structure and Oxidation State of Silica-Supported Manganese Oxide Catalysts and Reactivity for Acetone Oxidation with Ozone

Silica-supported manganese oxide catalysts with loadings of 3, 10, 15, and 20 wt % (as MnO2) were characterized with use of X-ray absorption spectroscopy and X-ray diffraction (XRD). The edge positions in the X-ray absorption spectra indicated that the oxidation state for the manganese decreased with increasing metal oxide loading from a value close to that of Mn2O3 (+3) to a value close to that of Mn3O4 (+2(2)/3). The XRD was consistent with these results as the diffractograms for the supported catalysts of higher manganese oxide loading matched those of a Mn3O4 reference. The reactivity of the silica-supported manganese oxide catalysts in acetone oxidation with ozone as an oxidant was studied over the temperature range of 300 to 600 K. Both oxygen and ozone produced mainly CO2 as the product of oxidation, but in the case of ozone the reaction temperature and activation energy were significantly reduced. The effect of metal oxide loading was investigated, and the activity for acetone oxidation was greater for a 10 wt % MnOx/SiO2 catalyst sample compared to a 3 wt % MnOx/SiO2 sample.
Arteriographic study of variant arterial anatomy of the upper extremities.

Anatomic variations in the major arteries of the upper extremities have been reported in 11–24.4% of individuals. In a review of 100 upper extremity arteriograms, we found an overall incidence of 9%. High origin of the radial artery from the brachial artery was the most frequently encountered anomaly occurring in 7% of individuals and accounting for 78% of all anatomic variations. Origin of the radial and ulnar arteries from the axillary artery was an infrequent finding occurring in only 2% of extremities.
A mother–infant therapy group model for postpartum depression

This pilot study examined the feasibility and efficacy of a manualized, 12-week mother-infant therapy group (M-ITG) model for women with moderate to severe depressive symptoms during the postpartum period. Study participants were referred to the psychiatric clinic of a university medical center for assessment and treatment for postpartum depression. Results of pre- and post comparisons utilizing self-report and observational measures showed that women in the M-ITG groups (n = 18) reported significantly fewer depressive symptoms and experienced their infants as more reinforcing following 12 weeks of treatment than did the depressed women in the waitlist control group (WLCG) (n = 14). Mothers in the M-ITG group also were rated as exhibiting significantly more positive affective involvement and communication in interactions with their infants following treatment than did mothers in the WLCG. The M-ITG model is described, and the implications of utilizing a mother-infant treatment approach for postpartum depression that focuses on the relationships as well as the mother's depressive symptoms is discussed. The importance of further examining the efficacy of the M-ITG model for women with postpartum depression and their families in a large-scale, randomized clinical trial is underscored.
Malignant peripheral nerve sheath tumors (MPNST): the Mayo Clinic experience.

Background Malignant peripheral nerve sheath tumors (MPNST) are a rare form of soft tissue sarcoma with few studies reporting on patient outcomes and prognostic variables.
Gametogenesis and Reproduction in the Wheat Nematode, Anguina Tritici1)

Oogenesis and spermatogenesis in Anguina tritici follow the classical pattern common in diploid amphimictic animals. Gonial cell multiplication occurs in the germinal zone of the gonads through regular mitotic divisions. Following a period of growth oocytes and spermatocytes undergo two regular maturation divisions. Fusion of sperm and egg pronuclei takes place regularly. The somatic chromosome number is 38 in both sexes. No sex chromosomes could be distinguished.
“Conditioned Air”: Evaluating an Environmentally Preferable Service

As industry moves toward a world of extended producer responsibility (EPR) in which ownership of products becomes less common and product leasing and service provisioning become more pervasive, it is increasingly important to develop frameworks for assessing the environmental impacts of the service industry. In this paper, we use streamlined life cycle assessment to compare the environmental impacts of a residential air conditioning unit with a proposed “conditioned air” service. When the entire life cycle is considered, the assessments indicate that the service option is environmentally preferable. By making the producer ultimately responsible for product repair and “take-back,” the service option creates incentives for the producer to design air conditioning units and their packaging for recovery, remanufacture, and recycling. This in turn minimizes the need for new raw materials and component parts. EPR also helps to ensure responsible unit maintenance and repair, which reduces chemical and oil dissipa...
Factors related to cigarette smoking during adolescent pregnancy

Previous research suggests that maternal smoking during pregnancy remains prevalent, particularly among adolescents. However, little is known about the factors related to smoking during adolescent pregnancy. The goal of the present study is to identify intrapersonal, familial, and peer factors that are related to smoking during adolescent pregnancy, and to determine the relative degree to which they affect this behavior. Interviews were conducted with 241 unmarried pregnant adolescents who planned to carry their pregnancies to term. Consistent with previous studies, 27% of the respondents reported daily smoking during pregnancy, and whites reported higher rates of use than members of other racial groups. Smoking during adolescent pregnancy was related to intrapersonal, familial, and peer factors. The results of a regression analysis suggest that perceived parental disapproval of smoking during pregnancy, friends' cigarette use, and race play a particularly important role in this behavior. The implications of these findings for preventive programs are discussed.
Results of Penetrating Keratoplasty in the Iridocorneal Endothelial Syndrome

Five patients (four men and one woman ranging in age from 30 to 41 years) with the iridocorneal endothelial syndrome (four with Chandler's syndrome and one with essential iris atrophy) underwent penetrating keratoplasty for complaints relating to diminished visual acuity or pain. After follow-up periods ranging from one year to four years and seven months (average, 2.7 years), postoperative visual acuities ranged from 20/15 to 20/30. No evidence of recurrence of the corneal abnormalities observed before grafting was apparent in the donor corneas at the last examinations. Two patients who required medical treatment for intraocular pressure control preoperatively also required adjuvant therapy postoperatively. These results suggested that penetrating keratoplasty is a relatively safe and effective procedure for patients with diminished vision or other complaints related to corneal abnormalities in the iridocorneal endothelial syndrome. It does not, however, restore to normal the iris and angle structures affected adversely by the progression of the corneal endotheliopathy and therefore other measures may be required to control intraocular pressure.
High-energy higher-order Born approximations: Theoretical development

The second and third terms of the generalized Born series are analyzed in an attempt to gain a series approximation to the differential cross section, valid through O (1/k/sup 2/), which treats all Born terms analogously. The resulting expressions for the second and third Born terms, derived from assumptions similar to those of Glauber theory, are compared with other analyses for the case of small-angle elastic scattering of electrons by hydrogen atoms. A most notable result is that, in addition to the Glauber-like term, there is a second term of O (1/k/sup 2/) which contributes to the real part of the third Born term. In addition, the angular range of maximum validity of the Glauber assumptions is established for inelastic collisions.
Fluorescence ratio mapping system for tissue diagnosis

A real time fluorescence ratio mapping a system for evaluating the surface of tissue can detect changes in tissue state including precancerous conditions. This system, using a personal computer and video camera, functions in near real-time, displaying pseudo color fluorescence intensity ratios maps at 15 frames per second. A fluorescence ratio mapping system functioning at close to video rates can be integrated with an endoscope to give the physician additional information during a patient exam about the state of a tissue. Preliminary measurements on ex vivo samples differentiated tumor from normal regions of tissues. Fluorescence spectral ratio maps give more structural detail of tissue than direct white light viewing. Tissue structure was observed in the fluorescence images. These results were correlated with histology.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Monitoring Round Goby (Neogobius melanostomus) Population Expansion in Eastern and Northern Lake Michigan

In the Great Lakes basin, round gobies (Neogobius melanostomus) were first reported from the St. Clair River in 1990. Reported here are the details of range extension and establishment of round gobies in eastern Lake Michigan at Grand Haven, Michigan and in northern Green Bay at Escanaba, Michigan. Round gobies were first collected in survey samples at Grand Haven in 1997 (0.0 to 0.5 fish per trawl hour). Catch rates increased in 1998 (1.5 to 3.0 fish/h) and 1999 (38.0 to 69.0 fish/h). Individuals collected by trawling (N = 207) ranged in total length from 18 to 94 mm. Round gobies were first collected in survey (trawl) samples at Escanaba in 1998 (7.5 fish/h; total length range 43 to 58 mm). Round gobies were also collected during 1999 in trawls at Muskegon and in gill nets at Grand Haven and Saugatuck. No round gobies were collected at five other eastern Lake Michigan ports sampled during this same time period (1995 to 1999). Numerous adult round gobies were captured by anglers at Grand Haven and Escanaba, indicating that these populations had been established for some time prior to being detected in survey sampling. Additional populations were verified from angler reports at Charlevoix (1998) and Kipling (1999), Michigan. Round gobies collected by anglers were generally larger, and taken in areas that are difficult to sample using conventional inshore sampling gear. These results indicate that survey and angler samples are complementary, but that up-to-date angler reports of exotic species that bite readily (round gobies) or are otherwise collected by anglers (Bythotrephes cederstroemi, Cercopagis pengoi) are critical to tracking the spread of these organisms.
Differential punishment of other behavior: Effects of pause-dependent shock on variable-interval performance

Three albino rats were exposed to a differential-punishment-of-other-behavior shock schedule superimposed on a variable-interval schedule of food presentation. With this arrangement, failure to barpress for a specified interval since the previous response resulted in delivery of shock. This procedure reliably decreased the number of specified pauses and was accompanied by increases in barpress rates and shifts in the distribution of responses. Subsequent exposure to noncontingent shock produced similar, but quantitatively smaller, changes for two of the three subjects. Training with barpress-dependent shock and reexposure to noncontingent shock further diminished these effects. This study demonstrates that pauses are conditionable units of behavior insofar as they are sensitive to a punishment contingency. In terms of the targeted unit of behavior, the current findings are similar to those obtained with barpress-dependent or interresponse-time-dependent shock schedules and suggest a continuum of response specification.
Baryon asymmetry of the universe and large lepton asymmetries

Abstract It is shown how a large lepton asymmetry of the universe L = (n v −n v )/n γ ⩾ 1 can lead to a small baryon asymmetry B = (n b − n b )/n γ ∼ 10 −9 via sphaleron mediated transitions.
Fairness and learning: an experimental examination

Abstract Over the last twenty years, experimental economists have identified a wide variety of games in which subjects display “other-regarding” behavior in violation of standard game theoretic predictions. The two primary approaches to explaining this behavior can be characterized as the “fairness hypothesis” and the “learning hypothesis.” Both hypotheses provide an adequate explanation of behavior in existing experiments, but the two approaches rely on very different interpretations of the factors underlying subjects' behavior. In this paper, we examine experiments with a step-level public goods game designed to distinguish between the fairness and learning hypotheses. We find that neither approach provides an adequate explanation of the experimental data by itself. We propose a model which synthesizes the fairness and learning hypotheses. Using econometric analysis, we demonstrate that this model provides a significantly better fit to the experimental data.
Electrochemistry and Spectroscopy of Sulfate Complexes of (Tetraphenylporphyrinato)manganese

The electrochemical and spectroscopic properties of [Mn2(tpp)2(SO4)] (H2tpp=tetraphenylporphyrin=5,10,15,20-tetraphenyl-21H,23H-porphine) were studied to characterize the stability of this compound as a function of solvent, redox state, and sulfate concentration. In non-coordinating solvents such as 1,2-dichloroethane, the dimer was stable, and two cyclic voltammetric waves were observed in the region for MnIII reduction. These waves correspond to reduction of the dimer to [MnII(tpp)] and [MnIII(tpp)(OSO3)]−, and reduction of [MnIII(tpp)(OSO3)]− to [MnII(tpp)(OSO3)]2−, respectively. In the coordinating solvent DMSO, [Mn2(tpp)2(SO4)] was unstable and dissociated to form [MnIII(tpp)(DMSO)2]+. A single voltammetric wave was observed for MnIII reduction in this solvent, corresponding to formation of [MnII(tpp)(DMSO)]. In non-coordinating solvent systems, addition of sulfate (as the bis(triphenylphosphoranylidene)ammonium (PPN+) salt) resulted in dimer dissociation, yielding [MnIII(tpp)(OSO3)]−. Reduction of this monomer produced [MnII(tpp)(OSO3)]2−. In DMSO, addition of SO led to displacement of solvent molecules forming [MnIII(tpp)(OSO3)]−. Reduction of this species in DMSO led to [MnII(tpp)(DMSO)].
Surface-induced dissociation of acetone cations from self-assembled monolayer surface of fluorinated alkyl thiol on Au (111) substrate at low collision energies

Abstract We have studied the dissociation of acetone molecular cations to acetyl cations following collision with a monolayer surface of fluorinated alkyl thiol (FC 12 ) self-assembled on Au (1 1 1) substrate at 13, 25.2 and 49.6 eV kinetic energies. Three energetically distinct dissociation processes contribute to total dissociation in this energy range. At all energies there is a common dissociation pathway involving loss of nearly all of the parent ion’s kinetic energy in the collision process. Fragment ions resulting from this dissociation mechanism are scattered over a wide range of angles. The second pathway, observed at 25.2 and 49.6 eV kinetic energy is delayed dissociation of collisionally excited acetone cations after only a small fraction of the ion’s kinetic energy is lost in the collision process. Fragment ions resulting from this unique dynamics feature are scattered close to the surface parallel. These dissociations take place after the excited ions have passed through the collision region and the energy analyzer and prior to their entering the mass analyzer. At 49.6 eV kinetic energy, a small intensity fragment ion peak appears at intermediate kinetic energy spectra between the low energy loss and the highly inelastic scattering peaks.
Capsule Commentary on Pyra et al., Sexual Minority Status and Violence Among HIV Infected and At-Risk Women

In this issue, Pyra et al.1 report on the associations between sexual minority status and violence exposure among women living with or at risk of HIV. Using data from the Women's Interagency HIV Study (WIHS) cohort, the authors found that women who identified as bisexual at baseline and those who reported having sex with men and women had relatively higher odds of experiencing ongoing sexual and physical violence, as well as partner psychological abuse. High-risk sex (having multiple partners or engaging in transactional sex) and ongoing substance use were identified as mediators, and childhood sexual abuse was a persistent confounder. These findings are robust, given 3 years of collected data per participant with retention rates exceeding 85 %, and time-updated variables that captured dynamic behaviors.
In-vivo microscopy using gradient index of refraction (GRIN) lens endoscopy

Many microsurgical procedures are performed on the threshold of what is humanly possible. In the particular case of retinal surgery, these limitations are manifested in both the physical and sensory domains. Physical limitations include tremor, fatigue and positional accuracy, while sensory limitations include both tactile sensation and visualization. Addressing these limitations will make surgery faster, safer, cheaper and more effective while enabling new classes of procedures to be developed. During retinal surgery, instruments are placed within the eye and observed through the pupil using a stereo operating microscope. While visualization using this method is quite good, the optical properties of the cornea, lens and vitreous prevent retinal structures smaller than approximately 10 microns in size from being seen. To view objects smaller than this, imperfections in the optical path must be corrected using either mathematics or adaptive optics, or be circumvented by placing a high-resolution endoscope next to the retina. This paper concentrates on the latter of these options by describing the use of GRIN lens endoscopy for in-vivo microscopic observation and diagnosis during retinal surgery. The GRIN lens endoscope is capable of significantly greater resolving power than the operating microscope, therefore increasing visualization during surgery and likewise permitting surgical procedures not currently possible.
Frequency shifts of the magnetic-resonance spectrum of mixtures of nuclear spin-polarized noble gases and vapors of spin-polarized alkali-metal atoms.

We report the first quantitative theoretical and experimental studies of frequency shifts of nuclear-magnetic-resonance (NMR) lines of noble-gas atoms and the corresponding frequency shifts of electron-paramagnetic-resonance (EPR) lines of alkali-metal atoms in mixtures of nuclear spin-polarized noble gases and vapors of spin-polarized alkali-metal atoms. The shifts are primarily due to the Fermi-contact hyperfine interaction. For the heavier noble gases there can be relatively large (\ensuremath{\approxeq}10%) contributions to the shifts from van der Waals molecules. The NMR frequencies of polarized $^{83}\mathrm{Kr}$ and $^{129}\mathrm{Xe}$ were measured in a vapor of spin-polarized alkali-metal atoms oriented parallel and antiparallel to the external magnetic field. The shift in the EPR frequency of the alkali-metal vapor due to the polarized noble-gas nuclei was measured simultaneously, thus providing a measurement of the absolute noble-gas nuclear polarization. The frequency shifts can be used as a convenient way to measure the absolute nuclear spin polarization of noble gases.
Variations in lower thermosphere dynamics at midlatitudes during intense geomagnetic storms

[1] High-resolution observations of the dynamics of the ionospheric E region (100–150 km) at midlatitudes have been made with the incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) during several intense geomagnetic storms (Kp ∼ 8–9). These included the storms of 25 September 1998, 15 July 2000, and 31 March 2001. The observations reveal electric fields of up to 100 mV/m during these events and indicate E region zonal plasma drifts of 300–1000 m/s, westward in the evening sector and eastward in the morning sector, with smaller meridional drifts. The tidal pattern of neutral winds in the lower thermosphere is heavily disrupted. The zonal component of the neutral wind follows convection-driven ion flow, while the meridional component shows a more complex response to geomagnetic forcing.
Spectral and meta-heuristic algorithms for software clustering

When large software systems are reverse engineered, one of the views that is produced is the system decomposition hierarchy. This hierarchy shows the system's subsystems, the contents of the subsystems (i.e., modules or other subsystems), and so on. Software clustering tools create the system decomposition automatically or semi-automatically with the aid of the software engineer. The Bunch software clustering tool shows how meta-heuristic search algorithms can be applied to the software clustering problem, successfully. Unfortunately, we do not know how close the solutions produced by Bunch are to the optimal solution. We can only obtain the optimal solution for trivial systems using an exhaustive search. This paper presents evidence that Bunch's solutions are within a known factor of the optimal solution. We show this by applying spectral methods to the software clustering problem. The advantage of using spectral methods is that the results this technique produces are within a known factor of the optimal solution. Meta-heuristic search methods only guarantee local optimality, which may be far from the global optimum. In this paper, we apply the spectral methods to the software clustering problem and make comparisons to Bunch. We conducted a case study to draw our comparisons and to determine if an efficient clustering algorithm, one that guarantees a near-optimal solution, can be created.
Energy Spectrum of Electrons Produced in Aluminum by 17.8-Mev Bremsstrahlung

A 60\ifmmode^\circ\else\textdegree\fi{} magnetic spectrometer is used to obtain a relative measurement of the integrated energy spectrum of secondary electrons produced at depths of one-half inch and four inches in aluminum by 17.8-Mev bremsstrahlung. The experimental spectra were found to agree with theoretical spectra calculated by the method due to Brysk to within the experimental error of 5%.
Forest investments and channels of contestation in highland Ethiopia

Increasing demands for forest products and services in forest-limited places such as Ethiopia necessitate deeper consideration of the social, political, ecological and economic institutions that underpin forest access. Given the key role that forests play in rural livelihoods, access limitations associated with emerging agricultural and forest-based foreign land investments have significant implications for communities located at the forest-farm interface. While private investment in Ethiopian forests is limited, a lack of citizen empowerment and transparent information inhibits local communities and advocates from effectively monitoring and protecting resource rights. This paper describes the tenure systems surrounding forests in Ethiopia today and examines two aspects of emerging forest investments in Ethiopia and highlights spaces within them for social transformation that might lead to more equitable benefit sharing. First, it describes the absence of a uniform definition of forestland, and a lack of ...
SOCIAL AND BEHAVIORAL CORRELATES OF PRESCHOOLERS WITH SPECIFIC LANGUAGE IMPAIRMENT

The relationship between specific subtypes of speech language impairment (SLI) and concomitant social competence and behavioral adjustment was investigated. Teachers and parents completed behavior ratings of SLI preschoolers enrolled in a language-based intervention program and preschoolers without language impairment, including the Parent-Child Rating Scale (P-CRS), Teacher-Child Rating Scale (T-CRS), and Social Competence and Behavior Evaluation Scale (SCBE). Teacher and parent ratings were analyzed across four SLI subtypes: expressive, receptive, pragmatic, and articulation. Results confirmed that children with greater language impairments had significantly more behavioral problems and poorer social competence than those children with articulation-only disorders and children without any impairments, and these results were observed in both home and school environments. SLI children had particular difficulty with task orientation, assertiveness, peer social skills, and frustration tolerance, and were more likely to be dependent and isolated in the classroom. Implications for assessment and intervention of SLI children were discussed. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 373–387, 2005.
A monte-carlo/molecular dynamics study of the diffusional recombination kinetics of C (a) + O (a) → CO (g) on Pt(111)

Abstract The diffusion constants for C and O adsorbates on Pt(111) surfaces have been calculated with Monte-Carlo/Molecular Dynamics techniques. The diffusion constants are determined to be D C ( T )=(3.4 × 10 −3 e −13156 T )cm 2 s −1 for carbon and D O ( T ) = (1.5×10 −3 e −9089 T ) cm 2 s −1 for oxygen. Using a recently developed diffusion model for surface recombination kinetics an approximate upper bound to the recombination rate constant of C and O on Pt(111) to produce CO (g) is found to be (9.4×10 −3 e −9089 T ) cm 2 s −1 .
Cognitive benefits of computer games for older adults

The purpose of this paper is to develop a basis for the hypothesis that digital action games may produce cognitive benefits for older adults. First, a discussion of the relationship between cognitive and physical health shows the increasing weight given to the role of declines in cognition in the development of dependency in older adult population studies. Second, evidence that cognitive training produces ‘far transfer’ in elders is presented. The key issue is that one approach, known as extended practice training, has been successful in producing far transfer to memory and other processes. Its principles, which are consistent with those associated with positive brain plasticity effects, are identified. Those principles are then related to the mechanics of digital action games, which also have the important added feature of producing the experiences of presence, engagement, and flow, the subjective elements of game play that are likely to sustain interest and emotional investment in the skills practiced so that the play produces cognitive benefits. The specific cognitive abilities proposed to be improved by different types of game genres are outlined, and recent developments in game and interface design that may affect the willingness of older adults to play are described.
Induction of Apoptosis in Tumor-Associated Endothelial Cells and Therapy of Orthotopic Human Pancreatic Carcinoma in Nude Mice

Although gemcitabine has been accepted as the first-line chemotherapeutic reagent for advanced pancreatic cancer, improvement of response rate and survival is not sufficient and patients often develop resistance. We hypothesized that the inhibition of phosphorylation of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) on tumor cells and tumor-associated endothelial cells, combined with gemcitabine, would overcome the resistance to gemcitabine in orthotopic pancreatic tumor animal model. L3.6pl, human pancreatic cancer cells growing in the pancreas, and tumor-associated endothelial cells in microorgan environment highly expressed phosphorylated EGFR, VEGFR, and Akt, which regulates antiapoptotic mechanism. Oral administration of AEE788 (dual tyrosine kinase inhibitor against EGFR and VEGFR) inhibited the phosphorylation of EGFR, VEGFR, and Akt on tumor-associated endothelial cells as well as tumor cells. Although intraperitoneal (i.p.) injection of gemcitabine showed limited inhibitory effect on tumor growth, combination with AEE788 and gemcitabine produced nearly 95% inhibition of tumor growth in parallel with a high level of apoptosis on tumor cells and tumor-associated endothelial cells, and decreased microvascular density and proliferation rate. Collectively, these data indicate that dual inhibition of phosphorylation of EGFR and VEGFR, in combination with gemcitabine, produces apoptosis of tumor-associated endothelial cells and significantly suppresses human pancreatic cancer in nude mice.
Two morphologically different mitochondrial populations in the rat hepatocyte as determined by quantitative three-dimensional electron microscopy.

Applying the Sjostrand technique of making three-dimensional reconstructions from serial thin sections for electron microscopy, it has been determined that rat liver mitochondria lack morphological homogeneity. Nearly 900 mitochondria from three hepatocytes of two specimens were analyzed. Within single cells there are two mitochondrial populations: rod- and V-shapes in a two-to-one ratio. Each population seems to be arrayed in the size gradient between the central vein and hepatic arteriole that has been established by Loud. The data suggest that the mitochondrial numbers vary so as to maintain relatively constant mitochondrial volume per cytoplasmic volume within the gradient. The present findings possibly allow new interpretations of other enzymological, cell fractionation, and zonal centrifugation data.
Symptom dimensions of disruptive behavior disorders in adolescent drivers.

Objective: Adolescents with disruptive behavior disorder, including ADHD, are more likely to engage in risky driving practices and, consequently, are more likely to be involved in a motor vehicle crash (MVC) than their non-ADHD peers. It is unclear whether symptoms of inattention, hyperactivity/impulsivity, or oppositional defiant disorder (ODD) increase risk of poor driving outcomes. Method: A total of 41 participants (16-19 years old) reported their ADHD and ODD symptoms and risky driving practices (errors and violations). History of citations and MVCs were acquired from state records. Relative predictive utility of symptom dimensions was assessed using multiple regressions. Results: Inattention solely predicted driving variables of interest: Greater levels of inattention were predictive of more citations, MVCs, and self-reported errors and violations. Conclusion: Findings suggest that symptoms of inattention play a primary role in driving-related problems among adolescents. Implications for future research and practice are discussed. Language: en
Structural Redesign for Forced Response with Proportional Damping by Large Admissible Perturbations

A method to solve redesign (inverse design) problems of complex structures with forced response amplitude constraints is developed. The assumption is made that a structure is excited by harmonic external forces at a given frequency. The problem is to find optimum values of structural characteristics in order to achieve a desired level of forced response at one or several locations on the structure. The method of large admissible perturbations (LEAP) is used. The main advantage of LEAP is that a solution of the inverse problem can be found automatically without trial and error or repetitive finite element analyses. Using this method, algorithms with modal dynamic constraints and static displacement constraints have been developed and tested in the past. In this paper the redesign problem with forced response amplitude constraints is formulated. The method consists of two distinctive parts. First, the general perturbation equations are derived. They provide relations between the original structure S1, which is known and has undesired forced response amplitudes, and the unknown objective structure S2. Second, the redesign problem is solved by an incremental prediction-correction scheme, which permits large changes in redesign. Structural damping is considered in the form of Rayleigh damping. Under this formulation the damping matrix can be diagonalized by use of the real mode shapes of the undamped structure, which leads to the derivation of an exact perturbation equation with no loss of accuracy. Modal dynamic and static constraints may also be imposed simultaneously by the designer. The algorithm produces accurate results for large changes in response amplitude without additional finite element analyses. The number of extracted modes and the increment size control the accuracy of the results and the computational time. The importance of the choice of the objective function is discussed, and examples are presented.
α-Fetoprotein and β-Human Chorionic Gonadotropin

Tumour markers can aid in areas such as diagnosis, surveillance of recurrence, staging and prognosis. This article focuses on 2 tumour markers, α-fetoprotein (AFP) and β-human chorionic gonadotropin (HCG). These tumour markers have been examined for their utility as prognostic indicators in 2 different manners. First, the marker level at diagnosis has been studied to determine if it is prognostic of outcome presumably because of its relation to tumour bulk or to the biological nature of the tumour. A more recent trend has been to investigate tumour marker decline. The finding of a delayed rate of decline suggests a poorer response of the malignancy to chemotherapy. The major focus of the article will be on marker decline of AFP and HCG as prognostic tools in peripheral and central nervous system (CNS) germ cell tumours (GCTs) and hepatic tumours (hepatoblastoma and hepatocellular carcinoma). The articles reviewed here suggest that HCG and AFP can correlate with survival if examined in specific ways, and could potentially be used to tailor treatment for individual patients. One group of authors presents data on patients with GCTs suggesting that satisfactory marker regression is an independent prognostic factor for survival. In a study of hepatoblastoma, data demonstrate that both the magnitude and rate of decline are associated with survival. Marker decline studies in hepatocellular carcinoma do not exist and marker levels at diagnosis do not appear to have a role in potential therapeutic changes. However, data on fucosylated subtype of AFP, Lens culinaris agglutinin A reactive AFP, has shown prognostic significance in hepatocellular carcinoma. The data for CNS GCTs are limited and studies examining serial cerebrospinal fluid HCG/AFP are ongoing. In some diseases, issues relating to timing of marker sampling when examining marker decline need to be studied in greater detail. Hopefully, marker decline studies can be duplicated in the other diseases, to document a potential role in determining outcome. Further studies are needed to test the ability to alter therapy in attempts to improve survival while decreasing toxicity to patients.
Geometric sensing of known planar shapes

Industrial assembly involves sensing the pose (orientation and position) of a part. Efficient and reliable sensing strategies can be developed for an assembly task if the shape of the part is known in advance. In this article we investigate two problems of determining the pose of a polygonal part of known shape for the cases of a continuum and a finite number of possible poses, respectively. The first problem, named sensing by inscription, involves determining the pose of a convex n-gon from a set of m supporting cones. An algorithm with running time O(nm) that almost always reduces to O(n + m log n) is presented to solve for all possible poses of the polygon. We prove that the number of possible poses cannot exceed 6n, given m ≥ 2 supporting cones with distinct vertices. Simulation experiments demonstrate that two supporting cones are sufficient to determine the real pose of the n-gon in most cases. Our results imply that sensing in practice can be carried out by obtaining viewing angles of a planar part at multiple exterior sites in the plane. On many occasions a parts feeder will have reduced the number of possible poses of a part to a small finite set. Our second problem, named sensing by point sampling, is concerned with a more general version: finding the minimum number of sensing points required to distinguish between n polygonal shapes with a total of m edges. In practice this can be implemented by embedding a series of point light detectors in a feeder tray or by using a set of mechanical probes that touch the feeder at a finite number of predetermined points. We show that this problem is equivalent to an NP-complete set-theoretic problem introduced as Discriminating Set, and present an O(n 2 m 2 ) approximation algorithm to solve it with a ratio of 2 In n. Furthermore, we prove that one can use an algorithm for Discriminating Set with ratio clog n to construct an algorithm for Set Covering with ratio clog n + O(log log n). Thus the ratio 2 In n is asymptotically optimal unless NP ⊂ DTIME(n poly log n ), a consequence of known results on approximating Set Covering. The complexity of subproblems of Discriminating Set is also analyzed, based on their relationship to a generalization of Independent Set called 3-Independent Set. Finally, simulation results suggest that sensing by point sampling is mostly applicable when poses are densely distributed in the plane.