Camacho, A. Gomez; Aguilera, E. F.; Gomes, P. R. S.; Lubian, J.
2007-10-15
Within the optical model for direct reactions, simultaneous calculations of elastic scattering, complete fusion, and total reaction cross sections for energies around the Coulomb barrier are presented for reactions involving the weakly bound projectile {sup 9}Be on {sup 64}Zn. Volume (W{sub F}) and surface (W{sub DR}) Woods-Saxon optical potentials are used such that the former is responsible only for complete fusion reactions while the latter for all direct reactions plus incomplete fusion. Simultaneous fits can be obtained with several sets of potential parameters, but if we impose the condition that the strength of W{sub F} is smaller than the strength of W{sub DR} at the tail region of the potential (this condition is discussed in detail), then values are required for r{sub F} and r{sub DR} of around 1.6 and 1.7-1.9 fm, respectively. These values are much larger than those frequently used in barrier penetration model calculations. Through the energy dependence of the real and imaginary parts of the polarization potentials, we show that the usual threshold anomaly does not show up for this system, but instead there is evidence of the presence of a breakup threshold anomaly.
Dasso, C. H.; Vitturi, A.
2009-03-04
We exploit a model describing the break-up of weakly-bound nuclei that can be used as a laboratory for testing different prescriptions that have been advanced in the literature to take into account the near-by presence of continuum states. In the model we follow the evolution of a single particle wave function in one dimension, initially bound by a Woods-Saxon type potential and then perturbed by a time- and position-dependent external field. Proper choices of this potential can simulate the effect of the interaction between reaction partners in a nuclear collision. These processes generate inelastic excitation probabilities that--distributed over the bound and continuum states of the system--lead to either a partial or a total fragmentation of the final wave function. The comparison with the exact calculations shows that standard coupled channel descriptions based on discretization of the continuum can be accurate only when a proper choice is made of the number of discrete states, of the energy mesh and of the energy cutoff. This may imply, even in simplified cases, the use of a rather large (and unpracticable) number of channels. The use of a more restricted number of channels may lead to misleading results.
Is Fusion Inhibited for Weakly Bound Nuclei?
Takahashi, J.; Munhoz, M.; Szanto, E.M.; Carlin, N.; Added, N.; Suaide, A.A.; de Moura, M.M.; Liguori Neto, R.; Szanto de Toledo, A.; Canto, L.F.
1997-01-01
Complete fusion of light radioactive nuclei is predicted to be hindered at near-barrier energies. This feature is investigated in the case of the least bound stable nuclei. Evaporation residues resulting from the {sup 6,7}Li+{sup 9}Be and {sup 6,7}Li+{sup 12}C fusion reactions have been measured in order to study common features in reactions involving light weakly bound nuclei. The experimental excitation functions revealed that the fusion cross section is significantly smaller than the total reaction cross section and also smaller than the fusion cross section expected from the available systematics. A clear correlation between the fusion probability and nucleon (cluster) separation energy has been established.The results suggest that the breakup process has a strong influence on the hindrance of the fusion cross section. {copyright} {ital 1996} {ital The American Physical Society}
Elastic scattering with weakly bound projectiles
Figueira, J. M.; Abriola, D.; Arazi, A.; Capurro, O. A.; Marti, G. V.; Martinez Heinmann, D.; Pacheco, A. J.; Testoni, J. E.; Barbara, E. de; Fernandez Niello, J. O.; Padron, I.; Gomes, P. R. S.; Lubian, J.
2007-02-12
Possible effects of the break-up channel on the elastic scattering threshold anomaly has been investigated. We used the weakly bound 6,7Li nuclei, which is known to undergo break-up, as projectiles in order to study the elastic scattering on a 27Al target. In this contribution we present preliminary results of these experiments, which were analyzed in terms of the Optical Model and compared with other elastic scattering data using weakly bound nuclei as projectile.
Fusion and Breakup of Weakly Bound Nuclei
Gomes, P. R. S.; Lubian, J.; Padron, I.; Crema, E.; Chamon, L. C.; Hussein, M. S.; Canto, L. F.
2006-08-14
We discuss the influence of the breakup process of weakly bound nuclei on the fusion cross section. The complete fusion for heavy targets is found to be suppressed due to the incomplete fusion following the breakup, whereas this effect is negligible for light targets. The total fusion cross sections for stable projectiles are not affected by the breakup process, whereas it is suppressed for halo projectiles. The non capture breakup is the dominant process at sub-barrier energies.
Scattering properties of weakly-bound dimers of Fermi atoms
NASA Astrophysics Data System (ADS)
Petrov, Dmitry
2005-03-01
We discuss the behavior of weakly bound bosonic dimers formed in a two-component Fermi gas with a large positive scattering length for the interspecies interaction. We present a theoretical approach for solving a few-body scattering problem and describe the physics of dimer-dimer elastic and inelastic scattering. We explain why these diatomic molecules, while in the highest ro-vibrational level, are characterized by remarkable collisional stability. Co-authors are Christophe Salomon, LKB, Ecole Normale Superieure, Paris, France; Georgy Shlyapnikov, LPTMS, University of South Paris, Orsay, France.
Resonance Enhanced Multiphoton Ionization (rempi) Spectroscopy of Weakly Bound Complexes
NASA Astrophysics Data System (ADS)
Muzangwa, Lloyd; Nyambo, Silver; Uhler, Brandon; Reid, Scott A.
2012-06-01
We have recently implemented Resonance Enhanced Multiphoton Ionization (REMPI) spectroscopy in our laboratory as a spectroscopic probe of transient species. We will report on initial gas-phase studies of the spectra of weakly bound van der Waals and halogen bonded complexes involving aromatic organic donors. The complexes are formed in the rarified environment of a supersonic molecular beam, which is skimmed prior to passing into the differentially pumped flight tube of a linear time-of-flight mass spectrometer. Ionization is initiated both by 1+1 and 1+1' REMPI schemes; the latter is used to minimize fragmentation. Our initial studies have examined van der Waals and halogen bonded complexes involving the phenol and toluene chromophores. Progress in the coupling of a discharge source into this apparatus will also be discussed.
Laboratory studies of weakly bound adducts of atmospheric interest
Wine, P.H.; Nicovich, J.M.; Stickel, R.E.; Hynes, A.J.
1995-12-31
It is now well-established that weakly bound adducts, i.e., species whose life-times toward unimolecular decomposition are only fractions of a second under atmospheric conditions, play an important role in tropospheric sulfur chemistry. In this presentation, recent results from our laboratory concerning the existence and atmospheric fates of two such weakly bound species, (CH{sub 3}){sub 2}S-OH and (CH{sub 3}){sub 2}S-Cl, will be discussed. In addition, evidence for the formation of weakly bound adducts in reactions of chlorine atoms with methyl halides will be presented.
Scattering properties of weakly bound dimers of fermionic atoms
Petrov, D.S.; Salomon, C.; Shlyapnikov, G.V.
2005-01-01
We consider weakly bound diatomic molecules (dimers) formed in a two-component atomic Fermi gas with a large positive scattering length for the interspecies interaction. We develop a theoretical approach for calculating atom-dimer and dimer-dimer elastic scattering and for analyzing the inelastic collisional relaxation of the molecules into deep bound states. This approach is based on the single-channel zero-range approximation, and we find that it is applicable in the vicinity of a wide two-body Feshbach resonance. Our results draw prospects for various interesting manipulations of weakly bound dimers of fermionic atoms.
Rotational and rotationless states of weakly bound molecules
Lemeshko, Mikhail; Friedrich, Bretislav
2009-05-15
By making use of the quantization rule of Raab and Friedrich [Phys. Rev. A 78, 022707 (2008)], we derive simple and accurate formulae for the number of rotational states supported by a weakly bound vibrational level of a diatomic molecule and the rotational constants of any such levels up to the threshold, and provide a criterion for determining whether a given weakly bound vibrational level is rotationless. The results depend solely on the long-range part of the molecular potential and are applicable to halo molecules.
Weakly bound states of the He-He-Mg trimer
Li Yong; Huang Deping; Gou Qingdong; Han Huili; Shi Tingyun
2011-07-15
We search for the existence of the weakly bound He-He-Mg molecules. The He-He-Mg molecule is treated as a three-body system. By using hyperspherical coordinates, the Schroedinger equation for the triatomic system is solved in the adiabatic approximation. We obtain that the binding of the three atoms is possible. The binding energies of such molecules are estimated.
Isospin Mixing and the Continuum Coupling in Weakly Bound Nuclei
Michel, N.; Nazarewicz, Witold; Ploszajczak, M.
2010-01-01
We investigate the near-threshold behavior of one-nucleon spectroscopic factors in mirror nuclei using the Gamow Shell Model, which simultaneously takes into account many-body correlations and continuum effects. We demonstrate that for weakly bound or unbound systems, the mirror symmetry-breaking effects are appreciable, and they manifest in large differences of spectroscopic factors in a mirror pair.
Intermolecular potential functions from spectroscopic properties of weakly bound complexes
Muenter, J.S.
1992-01-01
Goal is to consolidate the information from high resolution spectroscopy of weakly bound cluster molecules through a theoretical model of intermolecular potential energy surfaces. The ability to construct analytic intermolecular potential functions that accurately predict the interaction energy between small molecules will have a major impact in chemistry, biochemistry, and biology. This document presents the evolution and capabilities of a potential function model developed here, and then describes plans for future developments and applications. This potential energy surface (PES) model was first used on (HCCH){sub 2}, (CO{sub 2}){sub 2}, HCCH - CO{sub 2}; it had to be modified to work with HX dimers and CO{sub 2}-HX complexes. Potential functions have been calculated for 15 different molecular complexes containing 7 different monomer molecules. Current questions, logical extensions and new applications of the model are discussed. The questions are those raised by changing the repulsion and dispersion terms. A major extension of the PES model will be the inclusion of induction effects. Projects in progress include PES calculations on (HCCH){sub 3}, CO{sub 2} containing complexes, (HX){sub 2}, HX - CO{sub 2}, CO{sub 2} - CO, (CO{sub 2}){sub 3}, and (OCS){sub 2}. The first PES calculation for a nonlinear molecule will be for water and ammonia complexes. Possible long-term applications for biological molecules are discussed. Differences between computer programs used for molecular mechanics and dynamics in biological systems are discussed, as is the problem of errors. 12 figs, 74 refs. (DLC)
Millimeter/submillimeter Spectra of Weakly-Bound Clusters
NASA Astrophysics Data System (ADS)
Zou, Luyao; Widicus Weaver, Susanna L.
2016-06-01
Weakly-bound clusters are important for studying intermolecular interactions such as van der Waals forces and hydrogen bonding. The geometry and the effect of intermolecular force can be retrieved from their rovibrational spectra. Using a millimeter/submillimeter direct absorption spectrometer coupled with a fast-sweep detection technique, we are able to probe the ground vibrational state of weakly-bound molecules with high precision. With this spectrometer, we have fully characterized the pure rotational spectrum of trans-HO_3 up to 450 GHz. We have also identified lines in the trans-HO_3 spectrum as arising from the Ar-H_2O complex, and followed up with a full study of this cluster in the 200--850 GHz range. We are additionally studying proton-bound complexes that might have an impact in astrochemical environment, such as H_2--HCO^+. The experimental setup and the preliminary results for these complexes will be presented.
Description of weakly bound or unbound nuclear states
Kruppa, A.T.; Nazarewicz, W.
2004-09-13
A major theoretical challenge when dealing with weakly bound nuclei is to obtain a consistent microscopic description of bound states, resonances, and the non-resonant continuum. In this talk, resonances in deformed nuclei are described within the coupled-channel approach employing the Gamow state formalism. The coupled-channel method is compared with the expansion schemes employing the harmonic oscillator basis and the Berggren ensemble.
Proteomics of weakly bound cell wall proteins in rice calli.
Chen, Xiong-Yan; Kim, Sun Tae; Cho, Won Kyong; Rim, Yeonggil; Kim, Suwha; Kim, Seon-Won; Kang, Kyu Young; Park, Zee Yong; Kim, Jae-Yean
2009-05-01
In the present work, we present a proteomic analysis of weakly bound cell wall proteins (CWPs) in rice. CWPs from rice calli were extracted with mannitol/CaCl(2), followed by back extraction with water-saturated phenol. The isolated CWPs were evaluated for contamination by cytosolic proteins by measuring the enzymatic activity of an intracellular marker (glucose-6-phosphate dehydrogenase). This revealed the presence of low levels of intracellular proteins and a significant enrichment of CWPs, as compared to the total extract. Protein samples were digested in gels with trypsin and analyzed using the multidimensional protein identification technology (MudPIT). A total of 292 proteins were identified, which included numerous classical CWPs and antioxidant proteins. Bioinformatics analysis showed that 72.6% of these proteins possessed a signal peptide, and a total of 198 proteins were determined to be CWPs in rice. Functional classification divided the extracellular proteins into different groups, including glycosyl hydrolases (23%), antioxidant proteins (12%), cell wall structure-related proteins (6%), metabolic pathways (9%), protein modifications (4%), defense (4%), and protease inhibitors (3%). Furthermore, comparative analysis of our identified rice CWPs with known Arabidopsis CWPs revealed 25 novel rice-specific CWPs. The study described here is an unprecedented large-scale analysis of CWPs in rice.
Inclusive breakup of three-fragment weakly bound nuclei
NASA Astrophysics Data System (ADS)
Carlson, B. V.; Frederico, T.; Hussein, M. S.
2017-04-01
The inclusive breakup of three-fragment projectiles is discussed within a four-body spectator model. Both the elastic breakup and the non-elastic breakup are obtained in a unified framework. Originally developed in the 80's for two-fragment projectiles such as the deuteron, in this paper the theory is successfully generalized to three-fragment projectiles. The expression obtained for the inclusive cross section allows the extraction of the incomplete fusion cross section, and accordingly generalizes the surrogate method to cases such as (t, p) and (t, n) reactions. It is found that two-fragment correlations inside the projectile affect in a conspicuous way the elastic breakup cross section. The inclusive non-elastic breakup cross section is calculated and is found to contain the contribution of a three-body absorption term that is also strongly influenced by the two-fragment correlations. This latter cross section contains the so-called incomplete fusion where more than one compound nuclei are formed. Our theory describes both stable weakly bound three-fragment projectiles and unstable ones such as the Borromean nuclei.
Interplay of projectile breakup and target excitation in reactions induced by weakly bound nuclei
NASA Astrophysics Data System (ADS)
Gómez-Ramos, M.; Moro, A. M.
2017-03-01
Background: Reactions involving weakly bound nuclei require formalisms able to deal with continuum states. The majority of these formalisms struggle to treat collective excitations of the systems involved. For continuum-discretized coupled channels (CDCC), extensions to include target excitation have been developed but have only been applied to a small number of cases. Purpose: In this work, we reexamine the extension of the CDCC formalism to include target excitation and apply it to a variety of reactions to study the effect of breakup on inelastic cross sections. Methods: We use a transformed oscillator basis to discretize the continuum of the projectiles in the different reactions and use the extended CDCC method developed in this work to solve the resulting coupled differential equations. A new code has been developed to perform the calculations. Results: Reactions 58Ni(d ,d )*58Ni , 24Mg(d ,d )*24Mg , 144Sm(6Li,6Li)*144Sm , and 9Be(6Li,6Li)*9Be are studied. Satisfactory agreement is found between experimental data and extended CDCC calculations. Conclusions: The studied CDCC method has proven to be an accurate tool to describe target excitation in reactions with weakly bound nuclei. Moderate effects of breakup on inelastic observables are found for the reactions studied. Cross-section magnitudes are not modified much, but angular distributions present smoothing when opposed to calculations without breakup.
Semiclassical treatment of fusion processes in collisions of weakly bound nuclei
Canto, L.F.; Donangelo, R.; Marta, H.D.
2006-03-15
We describe a semiclassical treatment of nuclear fusion reactions involving weakly bound nuclei. In this treatment, the projectile-target relative motion is approximated by a classical trajectory while the intrinsic dynamics is handled by time-dependent quantum mechanics. The complete fusion probabilities are approximated by products of two factors: A tunneling probability and the probability that the system is in its ground state at the strong absorption radius. We investigate the validity of the method in a schematic two-channel application, where the continuum is represented by a single effective state with finite lifetime. Coupling effects below the Coulomb barrier are included through an analytical continuation of the time. Comparisons with full coupled-channels calculations are performed. The agreement between semiclassical and fully quantal calculations is quite good, suggesting that the procedure may be extended to more sophisticated discretizations of the continuum.
NASA Astrophysics Data System (ADS)
Kundu, A.; Santra, S.; Pal, A.; Chattopadhyay, D.; Nayak, B. K.; Saxena, A.; Kailas, S.
2016-07-01
Background: Complete fusion cross section measurements involving weakly bound projectiles show suppression at above-barrier energies compared to coupled-channels (CC) calculations, but no definite conclusion could be drawn for sub-barrier energies. Different CC models often lead to contrasting results. Purpose: We aim to investigate the differences in the fusion cross sections predicted by commonly used CC calculations, using codes such as fresco and ccfull, when compared to experimental data. Methods: The fusion cross sections are normalized to a dimensionless form by isolating the effect of only dynamic channel couplings calculated by both fresco and ccfull, by the method of fusion functions, and compared to a universal fusion function. This acts as a probe for obtaining the model dependence of fusion. Results: A difference is observed between the predictions of fresco and ccfull for all the reactions involving Li,76 as projectiles, and it is noticeably more for systems involving 7Li. Conclusions: With the theoretical foundations of the two CC models being different, their calculation of fusion is different even for the same system. The conclusion about the enhancement or suppression of fusion cross sections is model dependent.
Generalized Equations for the Inertial Tensor of a Weakly Bound Complex
NASA Astrophysics Data System (ADS)
Leopold, Kenneth R.
2013-06-01
A variety of methods have been employed for deriving intermolecular structural parameters from observed rotational constants of weakly bound complexes. Among these are methods that use formulas expressing the moments of inertia of the complex in terms of intermolecular coordinates and the known moments of inertia of the free monomers. While such formulas are available for a number of specific geometries, general forms have not been given. In this talk, equations are presented for the inertial tensor components of a weakly bound complex in terms of intermolecular coordinates and moments of inertia of the individual moieties. The result is a generalization of similar equations existing in the literature and allows for the use of up to three angles to specify the orientation of an asymmetric rotor within a complex. The angles used are well suited to treating the large amplitude motion characteristic of weakly bound systems and the resulting expressions should be useful in the analysis of the rotational constants of weakly bound systems with complicated geometries.
NASA Astrophysics Data System (ADS)
Mackenzie, Becca; Dewberry, Chris; Jarrett, Emma; Legon, Anthony; Leopold, Ken
2014-06-01
A-type rotational spectra of the weakly bound complex formed from pyridine and acetylene are reported. Contrary to expectation based on the symmetric structure of HCCH\\cdot \\cdot \\cdotNH3, the acetylene moiety in HCCH\\cdot\\cdot \\cdotNC5H5 does not lie along the symmetry axis of the pyridine. Rotational and 14N hyperfine constants instead indicate that, while the complex is indeed planar with an acetylenic hydrogen directed toward the nitrogen, the HCCH axis forms an angle of {˜}23° with the C2 axis of the pyridine. Spectra of HCCH\\cdot \\cdot \\cdotNC5H5, HCCD\\cdot \\cdot \\cdotNC5H5, DCCH\\cdot \\cdot \\cdotNC5H5, and DCCD\\cdot \\cdot \\cdotNC5H5 are all doubled, revealing the existence of a pair of low energy states. In light of the bent structure, this suggests a tunneling motion through a barrier at the C2v configuration. Because the splitting persists in the singly deuterated species, we conclude that the motion does not involve interchange of the acetylenic hydrogens. Single 13C substitution in either the ortho or meta positions of the pyridine eliminates the doubling and gives rise to separate sets of spectra for which the rotational constants are well predicted by a bent geometry. In this case, the two sets correspond to distinct species in which the 13C is either on the same or the opposite side as the acetylene. This further suggests that the doubling observed with unsubstituted pyridine arises from wagging of the acetylene, as such a tunneling motion is expected to be quenched when the pyridine is rendered asymmetric. The bent structure of the system may arise due to a secondary hydrogen bonding interaction between the ortho hydrogens of the pyridine and the π system of the acetylene.
Weakly bound molecules in the atmosphere: a case study of HOOO.
Murray, Craig; Derro, Erika L; Sechler, Timothy D; Lester, Marsha I
2009-03-17
Weakly bound molecules--particularly hydrated complexes of abundant atmospheric species--have long been postulated to play an important role in atmospherically relevant reactions. For example, such complexes could seed cloud formation and alter the global radiation budget. In this Account, we initially describe the current data on weakly bound species produced in association reactions of the hydroxyl radical (OH) with molecular partners, particularly oxygen (O(2)), nitric acid (HONO(2)), and nitrogen dioxide (NO(2)). Researchers have identified weakly bound association products of these reactions as the hydrogen trioxy (HOOO) radical, the doubly hydrogen-bonded OH-HONO(2) complex, and peroxynitrous acid (HOONO), respectively. In each case, previous kinetic studies of the reaction or OH vibrational relaxation processes have indicated unusual, non-Arrhenius behavior. Under the temperature-pressure conditions of the Earth's lower atmosphere, these processes exhibit a negative temperature dependence, indicative of an attractive interaction, or a pressure dependence. Researchers have subsequently carried out extensive theoretical studies of the properties of these weakly bound molecules, but the theoretical studies have lacked experimental validation. Next, we describe experimental studies to determine the vibrational frequencies and stability of HOOO as a prototypical example of these weakly bound molecules. We then use these data to assess its importance in the atmosphere. We discuss the efficient production of the HOOO radical from OH and O(2) under laboratory conditions and its subsequent detection using infrared action spectroscopy, a highly sensitive and selective double resonance technique. Using excitation of OH stretch and combination bands comprising OH stretch with lower frequency modes, we obtain detailed spectroscopic information on the vibrational modes of the two conformers of HOOO. In addition, we infer fundamental information about the dissociation
Towards extending the applicability of density functional theory to weakly bound systems
NASA Astrophysics Data System (ADS)
Wu, X.; Vargas, M. C.; Nayak, S.; Lotrich, V.; Scoles, G.
2001-11-01
While the attempts currently in progress in several groups for the rigorous inclusion of dispersion interactions in density functional theory (DFT) calculations mature and evolve into practical methodology, we contribute to the debate on the applicability of current functionals to the calculation of weak interaction with a systematic investigation of a few, typical, weakly bound systems. We have used both pure DFT and a hybrid approach in which the total interaction energy is partitioned into two parts: (a) the dispersion energy which, in a first approximation is the contribution due to intermonomer correlations and (b) all other interactions. The first component is accurately obtained at all distances of interest by means of a well-known damped multipolar expansion of the dispersion energy while for the second component different approximations will be evaluated. The need to avoid double counting a fraction of the correlation energy when using the hybrid approach and the choice of the appropriate functional are also discussed. We consider four systems of increasing binding strength, namely the Ar2 and Kr2 dimers, the benzene dimer, the water dimer, and a few metal carbonyls. For pure DFT calculations we confirm the conclusion reached by others concerning (a) the strong dependence of the results on the choice of the GGA functional for dispersion-dominated interaction (noble gases and benzene) with the overall tendency to yield underbinding and (b) the relatively accurate, functional-independent, description for that DFT gives of water, which we attribute to the fact that this system is dominated by electrostatic interactions. For the carbonyls we find that DFT yields results which area again strongly dependent on the choice of the functional and show a tendency to give overbinding. Our hybrid method shows instead shortcomings only for the noble gases. The problem in this case is traceable to the well-known difficulties that all current functionals experience at
Optical Potential Parameters of Weakly Bound Nuclear System 17F+13C
NASA Astrophysics Data System (ADS)
An, Guang-Peng; Lin, Cheng-Jian; Zhang, Huan-Qiao; Liu, Zu-Hua; Yang, Feng; Zhang, Gao-Long; Zhang, Chun-Lei; Wu, Zhen-Dong; Jia, Fei; Jia, Hui-Ming; Xu, Xin-Xing; Bai, Chun-Lin; Yu, Ning
2008-12-01
Elastic scattering angular distributions of the 14N+16O system and the angular distributions of transfer reaction 16O(14N,13 C)17 F at ELab = 76.2 MeV and 57MeV have been measured and calculated by means of the exact finite-range distorted-wave Born approximation with the PTOLEMY code. The optical potential parameters for the weakly bound nuclear system 17F+13 C have been deduced and applied to analyse the elastic scattering angular distributions of the similar systems 17F+12C and 17F+14N which are taken from literature. The result shows that the transfer reaction with stable projectile and target combination can be used as an alternative method to extract the optical potential parameters for the weakly bound nuclear system.
Pollard, T D; Bhandari, D; Maupin, P; Wachsstock, D; Weeds, A G; Zot, H G
1993-01-01
We used a novel stopped-flow/rapid-freezing machine to prepare the transient intermediates in the actin-myosin adenosine triphosphatase (ATPase) cycle for direct observation by electron microscopy. We focused on the low affinity complexes of myosin-adenosine triphosphate (ATP) and myosin-adenosine diphosphate (ADP)-Pi with actin filaments since the transition from these states to the high affinity actin-myosin-ADP and actin-myosin states is postulated to generate the molecular motion that drives muscle contraction and other types of cellular movements. After rapid freezing and metal replication of mixtures of myosin subfragment-1, actin filaments, and ATP, the structure of the weakly bound intermediates is indistinguishable from nucleotide-free rigor complexes. In particular, the average angle of attachment of the myosin head to the actin filament is approximately 40 degrees in both cases. At all stages in the ATPase cycle, the configuration of most of the myosin heads bound to actin filaments is similar, and the part of the myosin head preserved in freeze-fracture replicas does not tilt by more than a few degrees during the transition from the low affinity to high affinity states. In contrast, myosin heads chemically cross-linked to actin filaments differ in their attachment angles from ordered at 40 degrees without ATP to nearly random in the presence of ATP when viewed by negative staining (Craig, R., L.E. Greene, and E. Eisenberg. 1985. Proc. Natl. Acad. Sci. USA. 82:3247-3251, and confirmed here), freezing in vitreous ice (Applegate, D., and P. Flicker. 1987. J. Biol. Chem. 262:6856-6863), and in replicas of rapidly frozen samples. This suggests that many of the cross-linked heads in these preparations are dissociated from but tethered to the actin filaments in the presence of ATP. These observations suggest that the molecular motion produced by myosin and actin takes place with the myosin head at a point some distance from the actin binding site or does not
Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective
NASA Astrophysics Data System (ADS)
Diaz-Torres, A.; Boselli, M.
2016-05-01
Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.
Weakly bound states of the He-He-Ca triatomic system
NASA Astrophysics Data System (ADS)
Gou, Qingdong; Li, Yong
2012-01-01
We investigate for the existence of the weakly bound He-He-Ca molecules. By employing the best empirical interaction between each pair of particles, the Schrödinger equation for the triatomic system is solved using hyperspherical coordinates in the adiabatic approximation. The bound states are found for each of the 3He-3He-40Ca, 3He-4He-40Ca, and 4He-4He-40Ca trimers, respectively. The binding energies of such molecules are estimated. We discuss the features of the channel functions associated with the hyperspherical potential curves of each system to obtain insight into the geometry of the molecules.
Evolution of surface deformations of weakly bound nuclei in the continuum
NASA Astrophysics Data System (ADS)
Pei, J. C.; Zhang, Y. N.; Xu, F. R.
2013-05-01
We study weakly bound deformed nuclei based on the coordinate-space Skyrme Hartree-Fock-Bogoliubov (HFB) approach, in which a large box is employed for treating the continuum and large spatial extensions. When the limit of the core-halo deformation decoupling is approached, calculations found an exotic “egg”-like structure consisting of a spherical core plus a prolate halo in 38Ne, in which the near-threshold nonresonant continuum plays an essential role. Generally the halo probability and the decoupling effect in heavy nuclei can be hindered by high level densities around Fermi surfaces. However, deformed halos in medium-mass nuclei are possible as the negative-parity levels are sparse, e.g., in 110Ge. The deformation decoupling has also been demonstrated in pairing density distributions.
Structure Effects in Collisions Induced by Halo and Weakly Bound Nuclei around the Coulomb Barrier
NASA Astrophysics Data System (ADS)
Scuderi, V.; di Pietro, A.; Acosta, L.; Amorini, F.; Borge, M. J. G.; Figuera, P.; Fisichella, M.; Fraile, L. M.; Gomez-Camacho, J.; Jeppesen, H.; Lattuada, M.; Martel, I.; Milin, M.; Musumarra, A.; Papa, M.; Pellegriti, M. G.; Raabe, R.; Randisi, G.; Rizzo, F.; Santonocito, D.; Sanchez, E. M. R.; Scalia, G.; Tengblad, O.; Torresi, D.; Vidal, A. M.; Zadro, M.
In this contribution, results concerning different reaction channels for the collisions induced by the three Be isotopes, 9,10,11Be, on a 64Zn target at energies around the Coulomb barrier will be presented. The experiments with the radioactive 10,11Be beams were performed at REX-ISOLDE (CERN) whereas the experiment with the stable weakly bound 9Be beam was performed at LNS Catania. Elastic scattering angular distributions have been measured for the three systems 9,10,11Be + 64Zn at the same center of mass energy. The angular distributions were analyzed with optical potentials and reaction cross sections were obtained from optical model calculations, performed with the code PTOLEMY. For the 11Be + 64Zn reaction, the break-up angular distribution was also measured.
Study of weakly-bound odd-A nuclei with quasiparticle blocking
NASA Astrophysics Data System (ADS)
Xiong, Xue-Yu; Pei, Jun-Chen; Zhang, Yi-Nu; Zhu, Yi
2016-02-01
The coordinate-space Hartree-Fock-Bogoliubov (HFB) approach with quasiparticle blocking has been applied to study the odd-A weakly bound nuclei 17,19B and 37Mg, in which halo structures have been reported in experiments. The Skyrme nuclear forces SLy4 and UNEDF1 have been adopted in our calculations. The results with and without blocking have been compared to demonstrate the emergence of deformed halo structures due to blocking effects. In our calculations, 19B and 37Mg have remarkable features of deformed halos. Supported by National Key Basic Research Program of China (2013CB83440), National Natural Science Foundation of China (11375016, 11235001, 11320101004) and Research Fund for Doctoral Program of Higher Education of China (20130001110001)
Structure of the weakly bound triatomic He2Li and He2Na molecules
NASA Astrophysics Data System (ADS)
Suno, Hiroya
2017-07-01
We study the structure of triatomic molecules containing two helium atoms and one alkali-metal atom X (X = Li, Na). The three-body Schrödinger equation is solved in hyperspherical coordinates using the He-He and He-X pair van der Waals potentials available in the literature. We calculate the structural properties of the He2Li and He2Na bound states, and analyze one-dimensional pair and angle distribution functions as well as two-dimensional pair-pair and angle-angle distribution functions. These bound states are characterized by so peculiar weakly bound structures that classifying them into particular sizes and geometrical shapes appears to be elusive. Particularly, the JΠ=0+ excited states of He426Li and He427Li are found to constitute giant triatomic molecules with their size amounting to several hundred bohrs.
Brookes, Matthew D; Xia, Changhong; Tang, Jian; Anstey, James A; Fulsom, Bryan G; Au Yong, Ke-Xian; King, Jenna M; McKellar, A R W
2004-12-01
The design and operation of an apparatus for studying infrared spectra of weakly-bound complexes is described in detail. A pulsed supersonic jet expansion is probed using a tunable Pb-salt diode laser spectrometer operated in a rapid-scan mode. The jet may be fitted with either pinhole or slit shaped nozzles, the former giving lower effective rotational temperatures, and the latter giving sharper spectral lines. Notable features of the apparatus include use of a toroidal multi-pass mirror system to give over 100 passes of the laser through the supersonic jet, use of the normal laser controller for laser sweeping during both setup and data acquisition, and use of a simple semi-automated wavenumber calibration procedure. Performance of the apparatus is illustrated with observed spectra of the van der Waals complex He-OCS, and the seeded helium clusters He(N)-OCS and He(N)-CO.
Kinesin-8 Is a Low-Force Motor Protein with a Weakly Bound Slip State
Jannasch, Anita; Bormuth, Volker; Storch, Marko; Howard, Jonathon; Schäffer, Erik
2013-01-01
During the cell cycle, kinesin-8s control the length of microtubules by interacting with their plus ends. To reach these ends, the motors have to be able to take many steps without dissociating. However, the underlying mechanism for this high processivity and how stepping is affected by force are unclear. Here, we tracked the motion of yeast (Kip3) and human (Kif18A) kinesin-8s with high precision under varying loads using optical tweezers. Surprisingly, both kinesin-8 motors were much weaker compared with other kinesins. Furthermore, we discovered a force-induced stick-slip motion: the motor frequently slipped, recovered from this state, and then resumed normal stepping motility without detaching from the microtubule. The low forces are consistent with kinesin-8s being regulators of microtubule dynamics rather than cargo transporters. The weakly bound slip state, reminiscent of a molecular safety leash, may be an adaptation for high processivity. PMID:23746518
Ground-state properties of weakly bound helium-alkali trimers.
Stipanović, P; Vranješ Markić, L; Zarić, D; Boronat, J
2017-01-07
Weakly bound triatomic molecules consisting of two helium atoms and one alkali metal atom are studied by means of the diffusion Monte Carlo method. We determined the stability of (4)He2A, (4)He(3)HeA, and (3)He2A, where A is one of the alkali atoms Li, Na, K, Rb, or Cs. Some of the trimers with (3)He are predicted to be self-bound for the first time, but this is observed to be dependent on the He-A interaction potential model. In addition to the ground-state energy of the trimers, we determined their density, radial, and angular distributions. Many of them are spatially very extended, which qualifies them as quantum halo states.
Ground-state properties of weakly bound helium-alkali trimers
NASA Astrophysics Data System (ADS)
Stipanović, P.; Vranješ Markić, L.; Zarić, D.; Boronat, J.
2017-01-01
Weakly bound triatomic molecules consisting of two helium atoms and one alkali metal atom are studied by means of the diffusion Monte Carlo method. We determined the stability of 4He2A, 4He3HeA, and 3He2A, where A is one of the alkali atoms Li, Na, K, Rb, or Cs. Some of the trimers with 3He are predicted to be self-bound for the first time, but this is observed to be dependent on the He-A interaction potential model. In addition to the ground-state energy of the trimers, we determined their density, radial, and angular distributions. Many of them are spatially very extended, which qualifies them as quantum halo states.
Sub-barrier fusion of weakly bound 6Li with 58Ni
NASA Astrophysics Data System (ADS)
Aguilera, E. F.; Martinez-Quiroz, E.; Amador-Valenzuela, P.; Lizcano, D.; García-Flores, A.; Kolata, J. J.; Roberts, A.; Rogachev, G. V.; Peaslee, G. F.; Guimarães, V.; Becchetti, F. D.; Villano, A.; Ojaruega, M.; Chen, Y.; Jiang, H.; Febbraro, M.; DeYoung, P. A.; Belyaeva, T. L.
2017-08-01
Evaporation-proton yields were measured for the fusion of the weakly bound nucleus 6Li on a 58Ni target at six near- or sub-barrier bombarding energies. Effects of the one-neutron transfer reaction were estimated and corrections made. Total-fusion cross sections were deduced using calculated proton multiplicities. The resulting fusion excitation function shows a considerable enhancement with respect to calculations for a bare potential. Inelastic couplings are estimated to have insignificant effects on such fusion. The sum of total fusion plus one-neutron transfer cross sections nearly saturates the total reaction cross section in the energy region measured. Comparison with previous results appropriately scaled for the 6Li+(59Co , 64Ni, 64Zn) systems shows good consistency except for some data spread at the lower energies.
Role of nuclear couplings in the inelastic excitation of weakly-bound neutron-rich nuclei
Dasso, C.H.; Lenzi, S.M.; Vitturi, A.
1996-12-31
Much effort is presently devoted to the study of nuclear systems far from the stability line. Particular emphasis has been placed in light systems such as {sup 11}Li, {sup 8}B and others, where the very small binding energy of the last particles causes their density distribution to extend considerably outside of the remaining nuclear core. Some of the properties associated with this feature are expected to characterize also heavier systems in the vicinity of the proton or neutron drip lines. It is by now well established that low-lying concentrations of multipole strength arise from pure configurations in which a peculiar matching between the wavelength of the continuum wavefunction of the particles and the range of the weakly-bound hole states occurs. To this end the authors consider the break-up of a weakly-bound system in a heavy-ion collision and focus attention in the inelastic excitation of the low-lying part of the continuum. They make use of the fact that previous investigations have shown that the multipole response in this region is not of a collective nature and describe their excited states as pure particle-hole configurations. Since the relevant parameter determining the strength distributions is the binding energy of the last bound orbital they find it most convenient to use single-particle wavefunctions generated by a sperical square-well potential with characteristic nuclear dimensions and whose depth has been adjusted to give rise to a situation in which the last occupied neutron orbital is loosely-bound. Spin-orbit couplings are, for the present purpose, ignored. The results of this investigation clearly indicate that nuclear couplings have the predominant role in causing projectile dissociation in many circumstances, even at bombarding energies remarkably below the Coulomb barrier.
NASA Astrophysics Data System (ADS)
Trabelsi, T.; Ajili, Y.; Ben Yaghlane, S.; Jaidane, N.-E.; Mogren Al-Mogren, M.; Francisco, J. S.; Hochlaf, M.
2015-07-01
We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS- and HSN- together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH- + N, SN- + H, SN + H-, NH + S-, and NH- + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN- and H or SH- and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH-, SN-, and NH- lead either to the formation of HNS- or HSN- in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH-, SN-, and NH-, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN- and HNS- should be incorporated into H2S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.
Roncaratti, L. F. Leal, L. A.; Silva, G. M. de; Pirani, F.; Aquilanti, V.; Gargano, R.
2014-10-07
We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.
Oxidation of the Ru(0001) surface covered by weakly bound, ultrathin silicate films
Emmez, Emre; Anibal Boscoboinik, J.; Tenney, Samuel; ...
2015-06-30
Bilayer silicate films grown on metal substrates are weakly bound to the metal surfaces, which allows ambient gas molecules to intercalate the oxide/metal interface. In this work, we studied the interaction of oxygen with Ru(0001) supported ultrathin silicate and aluminosilicate films at elevated O2 pressures (10-5–10 mbar) and temperatures (450–923 K). The results show that the silicate films stay essentially intact under these conditions, and oxygen in the film does not exchange with oxygen in the ambient. O2 molecules readily penetrate the film and dissociate on the underlying Ru surface underneath. Also, the silicate layer does however strongly passivate themore » Ru surface towards RuO2(110) oxide formation that readily occurs on bare Ru(0001) under the same conditions. Lastly, the results indicate considerable spatial effects for oxidation reactions on metal surfaces in the confined space at the interface. Moreover, the aluminosilicate films completely suppress the Ru oxidation, providing some rationale for using crystalline aluminosilicates in anti-corrosion coatings.« less
Hyperaccretion during tidal disruption events: Weakly bound debris envelopes and jets
Coughlin, Eric R.; Begelman, Mitchell C. E-mail: mitch@jila.colorado.edu
2014-02-01
After the destruction of the star during a tidal disruption event (TDE), the cataclysmic encounter between a star and the supermassive black hole (SMBH) of a galaxy, approximately half of the original stellar debris falls back onto the hole at a rate that can initially exceed the Eddington limit by orders of magnitude. We argue that the angular momentum of this matter is too low to allow it to attain a disk-like configuration with accretion proceeding at a mildly super-Eddington rate, the excess energy being carried away by a combination of radiative losses and radially distributed winds. Instead, we propose that the infalling gas traps accretion energy until it inflates into a weakly bound, quasi-spherical structure with gas extending nearly to the poles. We study the structure and evolution of such 'zero-Bernoulli accretion' flows as a model for the super-Eddington phase of TDEs. We argue that such flows cannot stop extremely super-Eddington accretion from occurring, and that once the envelope is maximally inflated, any excess accretion energy escapes through the poles in the form of powerful jets. We compare the predictions of our model to Swift J1644+57, the putative super-Eddington TDE, and show that it can qualitatively reproduce some of its observed features. Similar models, including self-gravity, could be applicable to gamma-ray bursts from collapsars and the growth of SMBH seeds inside quasi-stars.
Oxidation of the Ru(0001) surface covered by weakly bound, ultrathin silicate films
Emmez, Emre; Anibal Boscoboinik, J.; Tenney, Samuel; Sutter, Peter; Shaikhutdinov, Shamil; Freund, Hans-Joachim
2015-06-30
Bilayer silicate films grown on metal substrates are weakly bound to the metal surfaces, which allows ambient gas molecules to intercalate the oxide/metal interface. In this work, we studied the interaction of oxygen with Ru(0001) supported ultrathin silicate and aluminosilicate films at elevated O_{2} pressures (10^{-5}–10 mbar) and temperatures (450–923 K). The results show that the silicate films stay essentially intact under these conditions, and oxygen in the film does not exchange with oxygen in the ambient. O_{2} molecules readily penetrate the film and dissociate on the underlying Ru surface underneath. Also, the silicate layer does however strongly passivate the Ru surface towards RuO_{2}(110) oxide formation that readily occurs on bare Ru(0001) under the same conditions. Lastly, the results indicate considerable spatial effects for oxidation reactions on metal surfaces in the confined space at the interface. Moreover, the aluminosilicate films completely suppress the Ru oxidation, providing some rationale for using crystalline aluminosilicates in anti-corrosion coatings.
Photodissociation dynamics of weakly bound He H2 + in intense light fields
NASA Astrophysics Data System (ADS)
Szidarovszky, Tamás; Yamanouchi, Kaoru
2016-12-01
Photoinduced dynamics of a weakly bound triatomic molecule He H2 + exposed to electromagnetic radiation is investigated by time-dependent quantum wave-packet propagation. Adopting a two-dimensional linear H-H-He model, the three lowest-lying potential energy surfaces (PESs) and corresponding dipole moment surfaces are constructed. One of the two characteristic excited PESs of He H2 + leads to the charge-transfer reaction H2 ++He → H2+H e+ and the other corresponds to the first excited state of H2 + perturbed by the presence of He. When He H2 + is exposed to a femtosecond intense ultraviolet light pulse (I =4 ×1014W c m-2 , λ =400 nm ), both of the two excited PESs are found to be coupled with the light field and a variety of reaction pathways become opened so that HeH, He H+ , H2, H2 +,H , H+ , He, and H e+ are produced. Simulations also show that the anharmonic coupling between the two stretching vibrational modes in He H2 + leads to the stabilization of the H2 + moiety against the decomposition into H + H+ compared with bare H2 +. The theoretical findings of the formation of He H+ composed of the most abundant elements in the universe are also discussed in view of the theoretical modeling of the chemical reactions proceeding in the primordial gas and in the interstellar medium.
Muenter, J.S.
1992-08-01
Goal is to consolidate the information from high resolution spectroscopy of weakly bound cluster molecules through a theoretical model of intermolecular potential energy surfaces. The ability to construct analytic intermolecular potential functions that accurately predict the interaction energy between small molecules will have a major impact in chemistry, biochemistry, and biology. This document presents the evolution and capabilities of a potential function model developed here, and then describes plans for future developments and applications. This potential energy surface (PES) model was first used on (HCCH){sub 2}, (CO{sub 2}){sub 2}, HCCH - CO{sub 2}; it had to be modified to work with HX dimers and CO{sub 2}-HX complexes. Potential functions have been calculated for 15 different molecular complexes containing 7 different monomer molecules. Current questions, logical extensions and new applications of the model are discussed. The questions are those raised by changing the repulsion and dispersion terms. A major extension of the PES model will be the inclusion of induction effects. Projects in progress include PES calculations on (HCCH){sub 3}, CO{sub 2} containing complexes, (HX){sub 2}, HX - CO{sub 2}, CO{sub 2} - CO, (CO{sub 2}){sub 3}, and (OCS){sub 2}. The first PES calculation for a nonlinear molecule will be for water and ammonia complexes. Possible long-term applications for biological molecules are discussed. Differences between computer programs used for molecular mechanics and dynamics in biological systems are discussed, as is the problem of errors. 12 figs, 74 refs. (DLC)
Infrared Spectrum of CO-O2, a 'new' Weakly-Bound Complex
NASA Astrophysics Data System (ADS)
McKellar, Bob; Barclay, A. J.; Michaelian, K. H.; Moazzen-Ahmadi, Nasser
2016-06-01
Only a few weakly-bound complexes containing the O2 molecule have been characterized by high-resolution spectroscopy, notably N2O-O2 [1] and HF-O2 [2]. This neglect is no doubt due in part to the complications added by the oxygen unpaired electron spin. Here we report an extensive infrared spectrum of CO-O2, as observed in the CO fundamental band region (˜2150 wn) using a tunable quantum cascade laser to probe a pulsed supersonic jet expansion. The derived energy level pattern consists of 'stacks' characterized by K, the projection of the total angular momentum on the intermolecular axis. Five such stacks are observed in the ground vibrational state, and ten in the excited state, v(CO) = 1. They are divided into two groups, with no observed transitions between groups, and we believe these groups correlate with the two lowest rotational states of O2, namely (N, J) = (1, 0) and (1, 2). In many ways, the spectrum and energy levels are similar to those of CO-N2 [3], and we use the same approach for analysis, simply fitting each stack with its own origin, B-value, and distortion constants. The rotational constant of the lowest stack in the ground state (with K = 0) implies an effective intermolecular separation of 3.82 Å, but this should be interpreted with caution since it ignores possible effects of electron spin. [1] H.-B. Qian, D. Seccombe, and B.J. Howard, J. Chem. Phys. 107, 7658 (1997). [2] W.M. Fawzy, C.M. Lovejoy, D.J. Nesbitt, and J.T. Hougen, J. Chem. Phys. 117, 693 (2002); S. Wu, G. Sedo, E.M. Grumstrup, and K.R. Leopold, J. Chem. Phys. 127, 204315 (2007). [3] M. Rezaei, K.H. Michaelian, N. Moazzen-Ahmadi, and A.R.W. McKellar, J. Phys. Chem. A 117, 13752 (2013), and references therein.
NASA Astrophysics Data System (ADS)
Diaz-Torres, Alexis
2011-04-01
A self-contained Fortran-90 program based on a three-dimensional classical dynamical reaction model with stochastic breakup is presented, which is a useful tool for quantifying complete and incomplete fusion, and breakup in reactions induced by weakly-bound two-body projectiles near the Coulomb barrier. The code calculates (i) integrated complete and incomplete fusion cross sections and their angular momentum distribution, (ii) the excitation energy distribution of the primary incomplete-fusion products, (iii) the asymptotic angular distribution of the incomplete-fusion products and the surviving breakup fragments, and (iv) breakup observables, such as angle, kinetic energy and relative energy distributions. Program summaryProgram title: PLATYPUS Catalogue identifier: AEIG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 332 342 No. of bytes in distributed program, including test data, etc.: 344 124 Distribution format: tar.gz Programming language: Fortran-90 Computer: Any Unix/Linux workstation or PC with a Fortran-90 compiler Operating system: Linux or Unix RAM: 10 MB Classification: 16.9, 17.7, 17.8, 17.11 Nature of problem: The program calculates a wide range of observables in reactions induced by weakly-bound two-body nuclei near the Coulomb barrier. These include integrated complete and incomplete fusion cross sections and their spin distribution, as well as breakup observables (e.g. the angle, kinetic energy, and relative energy distributions of the fragments). Solution method: All the observables are calculated using a three-dimensional classical dynamical model combined with the Monte Carlo sampling of probability-density distributions. See Refs. [1,2] for further details. Restrictions: The
Monteiro, D. S.; Otomar, D. R.; Lubian, J.; Gomes, P. R. S.; Arazi, A.; Figueira, J. M.; Heimann, D. Martinez; Negri, A. E.; Pacheco, A. J.; Niello, J. O. Fernandez; Guimaraes, V.
2009-01-15
High-precision data of backward-angle elastic and quasielastic scattering for the weakly bound {sup 6}Li projectile on {sup 144}Sm target at deep-sub-barrier, near-, and above-barrier energies were measured. From the deep-sub-barrier data, the surface diffuseness of the nuclear interacting potential was studied. Barrier distributions were extracted from the first derivatives of the elastic and quasielastic excitation functions. It is shown that sequential breakup through the first resonant state of the {sup 6}Li is an important channel to be included in coupled-channels calculations, even at deep-sub-barrier energies.
NASA Astrophysics Data System (ADS)
Brown, David F. R.; Gibbs, Mark N.; Clary, David C.
1996-11-01
We describe a new method to calculate the vibrational ground state properties of weakly bound molecular systems and apply it to (HF)2 and HF-HCl. A Bayesian Inference neural network is used to fit an analytic function to a set of ab initio data points, which may then be employed by the quantum diffusion Monte Carlo method to produce ground state vibrational wave functions and properties. The method is general and relatively simple to implement and will be attractive for calculations on systems for which no analytic potential energy surface exists.
Labbe, Nicole J; Sivaramakrishnan, Raghu; Goldsmith, C Franklin; Georgievskii, Yuri; Miller, James A; Klippenstein, Stephen J
2016-01-07
Weakly bound free radicals have low-dissociation thresholds such that at high temperatures, time scales for dissociation and collisional relaxation become comparable, leading to significant dissociation during the vibrational-rotational relaxation process. Here we characterize this "prompt" dissociation of formyl (HCO), an important combustion radical, using direct dynamics calculations for OH + CH2O and H + CH2O (key HCO-forming reactions). For all other HCO-forming reactions, presumption of a thermal incipient HCO distribution was used to derive prompt dissociation fractions. Inclusion of these theoretically derived HCO prompt dissociation fractions into combustion kinetics models provides an additional source for H-atoms that feeds chain-branching reactions. Simulations using these updated combustion models are therefore shown to enhance flame propagation in 1,3,5-trioxane and acetylene. The present results suggest that HCO prompt dissociation should be included when simulating flames of hydrocarbons and oxygenated molecules and that prompt dissociations of other weakly bound radicals may also impact combustion simulations.
Labbe, Nicole J.; Sivaramakrishnan, Raghu; Goldsmith, C. Franklin; Georgievskii, Yuri; Miller, James A.; Klippenstein, Stephen J.
2016-01-07
Weakly bound free radicals have low-dissociation thresholds such that at high temperatures, timescales for dissociation and collisional relaxation become comparable, leading to significant dissociation during the vibrational-rotational relaxation process. Here we characterize this “prompt” dissociation of formyl (HCO), an important combustion radical, using direct dynamics calculations for OH + CH2O and H + CH2O (key HCO-forming reactions). For all other HCO-forming reactions, presumption of a thermal incipient HCO distribution was used to derive prompt dissociation fractions. Inclusion of these theoretically derived HCO prompt dissociation fractions into combustion kinetics models provides an additional source for H-atoms that feeds chain branching reactions. Simulations using these updated combustion models are therefore shown to enhance flame propagation in 1,3,5-trioxane and acetylene. The present results suggest that HCO prompt dissociation should be included when simulating flames of hydrocarbons and oxygenated molecules and that prompt dissociations of other weakly bound radicals may also impact combustion simulations
Evidence for a dynamically refracted primary bow in weakly bound 9Be rainbow scattering from 16O
NASA Astrophysics Data System (ADS)
Ohkubo, S.; Hirabayashi, Y.
2016-09-01
We present for the first time evidence for the existence of a dynamically refracted primary bow for 9Be+16O scattering. This is demonstrated through the use of coupled channel calculations with an extended double folding potential derived from the density-dependent effective two-body force and precise microscopic cluster wave functions for 9Be. The calculations reproduce the experimental Airy structure in 9Be+16O scattering well. It is found that coupling of a weakly bound 9Be nucleus to excited states plays the role of a booster lens, dynamically enhancing the refraction over the static refraction due to the Luneburg lens mean field potential between the ground states of 9Be and 16O.
Keswani, Neelam; Choudhary, Sinjan; Kishore, Nand
2010-07-01
The thermodynamics of interaction of neomycin and lincomycin with bovine serum albumin (BSA) and human serum albumin (HSA) has been studied using isothermal titration calorimetry (ITC), in combination with UV-visible, steady state and time resolved fluorescence spectroscopic measurements. Neomycin is observed to bind weakly to BSA and HSA whereas lincomycin did not show any evidence for binding with the native state of these proteins, rather it interacts in the presence of surfactants. The ITC results suggest 1 : 1 binding stoichiometry for neomycin in the studied temperature range. The values of the van't Hoff enthalpy do not agree with the calorimetric enthalpy in the case of neomycin, suggesting conformational changes in the protein upon ligand binding, as well as with the rise in the temperature. Experiments at different ionic strengths, and in the presence of tetrabutyl ammonium bromide and surfactants suggest the predominant involvement of electrostatic interactions in the complexation process of neomycin with BSA and HSA, and non-specific interaction behaviour of lincomycin with these proteins.
NASA Astrophysics Data System (ADS)
Nedukha, E. M.
The pyroantimonate method was used to study the localization of free and weakly bound calcium in cells of moss protonema of Funaria hygrometrica Hedw. cultivated on a clinostat (2 rev/min). Electroncytochemical study of control cells cultivated at 1 g revealed that granular precipitate marked chloroplasts, mitochondria, Golgi apparatus, lipid drops, nucleoplasma, nucleolus, nucleus membranes, cell walls and endoplasmic reticulum. In mitochondria the precipitate was revealed in stroma, in chloroplast it was found on thylakoids and envelope membranes. The cultivation of protonema on clinostat led to the intensification in cytochemical reaction product deposit. A considerable intensification of the reaction was noted in endomembranes, vacuoles, periplasmic space and cell walls. At the same time analysis of pectinase localization was made using the electroncytochemical method. A high reaction intensity in walls in comparison to that in control was found out to be a distinctive pecularity of the cells cultivated on clinostat. It testifies to the fact that increasing of freee calcium concentrations under conditions of clinostation is connected with pectinic substances hydrolysis and breaking of methoxy groups of pectins. Data obtained are discussed in relation to problems of possible mechanisms of disturbance in calcium balance of plant cells and the role of cell walls in gomeostasis of cell grown under conditions of simulated weighlessness.
Problems pilots face involving wind shear
NASA Technical Reports Server (NTRS)
Melvin, W. W.
1977-01-01
Educating pilots and the aviation industry about wind shears presents a major problem associated with this meteorological phenomenon. The pilot's second most pressing problem is the need for a language to discuss wind shear encounters with other pilots so that the reaction of the aircraft to the wind shear encounter can be accurately described. Another problem is the flight director which gives a centered pitch command for a given angular displacement from the glide slope. It was suggested that they should instead be called flight path command and should not center unless the aircraft is actually correcting to the flight path.
NASA Astrophysics Data System (ADS)
Topic, Wendy C.; Jäger, Wolfgang
2005-08-01
Rotational spectra of the weakly bound He-HCCCN and He-DCCCN van der Waals complexes were observed using a pulsed-nozzle Fourier-transform microwave spectrometer in the 7-26-GHz frequency region. Nuclear quadrupole hyperfine structures due to the N14 and D nuclei (both with nuclear-spin quantum number I =1) were resolved and assigned. Both strong a and weaker b-type transitions were observed and the assigned transitions were used to fit the parameters of a distortable asymmetric rotor model. The dimers are floppy, near T-shaped complexes. Three intermolecular potential-energy surfaces were calculated using the coupled-cluster method with single and double excitations and noniterative inclusion of triple excitations. Bound-state rotational energy levels supported by these surfaces were determined. The quality of the potential-energy surfaces was assessed by comparing the experimental and calculated transition frequencies and also the corresponding spectroscopic parameters. Simple scaling of the surfaces improved both the transition frequencies and spectroscopic constants. Five other recently reported surfaces [O. Akin-Ojo, R. Bukowski, and K. Szalewicz, J. Chem. Phys. 119, 8379 (2003)], calculated using a variety of methods, and their agreement with spectroscopic properties of He-HCCCN are discussed.
Observation of a C-H\\cdotsAROMATIC Interaction in the FLUOROBENZENE\\cdotsHCCH Weakly Bound Complex
NASA Astrophysics Data System (ADS)
Ulrich, Nathan W.; Peebles, Sean A.; Peebles, Rebecca A.; Dhahir, Yasser J.; Seifert, Nathan A.; Perez, Cristobal; Pate, Brooks H.
2013-06-01
Chirped-pulse Fourier-transform microwave (CP-FTMW) spectroscopy has been used to determine the structure of the C_6H_5F\\cdotsHCCH weakly bound complex. Assignment of spectra for the parent and all six unique ^{13}C isotopologues in natural abundance has allowed a full structure determination, using both Kraitchman substitution and least-squares methods. The acetylene lies nearly perpendicular to the fluorobenzene ring, approximately above the ring center, and in the dimer ab symmetry plane. There is a slight tilt of the hydrogen atom nearest the fluorobenzene away from the carbon atom bonded to the fluorine. The distance between the centers of mass of the two monomers is approximately 4.18(1)Å, with C-H\\cdotsC distances of between 2.81(1)Å and 2.92(1)Å. The experimentally determined structure is in reasonable agreement with the minimum energy configuration from an MP2/6-311++G(2d,2p) ab initio calculation. Comparison will also be made with similar complexes of aromatic compounds with potential hydrogen bond donors.
Figuera, P.; Cardella, G.; Di Pietro, A.; Lu, J.; Marchetta, C.; Papa, M.; Tian, W.; Amorini, F.; Cherubini, S.; Lattuada, M.; Musumarra, A.; Pizzone, R. G.; Rizzo, F.; Scuderi, V.; Angulo, C.; Casarejos, E.; Pellegriti, M. G.; Raabe, R.; Sida, J. L.
2006-08-14
The study of reaction mechanisms in collisions induced by halo and/or weakly bound nuclei around the barrier has recently been the subject of many theoretical and experimental papers. Here we discuss our recent results concerning the study of the systems 13N+9Be and 6He+64Zn.
NASA Astrophysics Data System (ADS)
Cook, K. J.; Simpson, E. C.; Luong, D. H.; Kalkal, Sunil; Dasgupta, M.; Hinde, D. J.
2016-06-01
Background: Complete fusion cross sections in collisions of light weakly bound nuclei and high-Z targets show suppression of complete fusion at above-barrier energies. This has been interpreted as resulting from the breakup of the weakly bound nucleus prior to reaching the fusion barrier, reducing the probability of complete charge capture. Below-barrier studies of reactions of 9Be have found that the breakup of 8Be formed by neutron stripping dominates over direct breakup and that transfer-triggered breakup may account for the observed suppression of complete fusion. Purpose: This paper investigates how the above conclusions are affected by lifetimes of the resonant states that are populated prior to breakup. If the mean life of a populated resonance (above the breakup threshold) is much longer than the fusion time scale, then its breakup (decay) cannot suppress complete fusion. For short-lived resonances, the situation is more complex. This work explicitly includes the mean life of the short-lived 2+ resonance in 8Be in classical dynamical model calculations to determine its effect on energy and angular correlations of the breakup fragments and on model predictions of suppression of cross sections for complete fusion at above-barrier energies. Method: Previously performed coincidence measurements of breakup fragments produced in reactions of 9Be with 144Sm, 168Er, 186W, 196Pt, 208Pb, and 209Bi at energies below the barrier have been reanalyzed using an improved efficiency determination of the BALiN detector array. Predictions of breakup observables and of complete and incomplete fusion at energies above the fusion barrier are then made using the classical dynamical simulation code platypus, modified to include the effect of lifetimes of resonant states. Results: The agreement of the breakup observables is much improved when lifetime effects are included explicitly. Sensitivity to subzeptosecond lifetime is observed. The predicted suppression of complete fusion
Trabelsi, T.; Ajili, Y.; Ben Yaghlane, S.; Jaidane, N.-E.; Mogren Al-Mogren, M.; Francisco, J. S.; Hochlaf, M.
2015-07-21
We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS{sup −} and HSN{sup −} together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH{sup −} + N, SN{sup −} + H, SN + H{sup −}, NH + S{sup −}, and NH{sup −} + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN{sup −} and H or SH{sup −} and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH{sup −}, SN{sup −}, and NH{sup −} lead either to the formation of HNS{sup −} or HSN{sup −} in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH{sup −}, SN{sup −}, and NH{sup −}, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN{sup −} and HNS{sup −} should be incorporated into H{sub 2}S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.
Goble, J.H. Jr.
1982-05-01
Three variations on the Dunham series expansion function of the potential of a diatomic molecule are compared. The differences among these expansions lie in the choice of the expansion variable, lambda. The functional form of these variables are lambda/sub s/ = l-r/sub e//r for the Simon-Parr-Finlan version, lambda/sub T/ - 1-(r/sub e//r)/sup p/ for that of Thakkar, and lambda/sub H/ = 1-exp(-rho(r/r/sub e/-1) for that of Huffaker. A wide selection of molecular systems are examined. It is found that, for potentials in excess of thirty kcal/mole, the Huffaker expansion provides the best description of the three, extrapolating at large internuclear separation to a value within 10% of the true dissociation energy. For potentials that result from the interaction of excited states, all series expansions show poor behavior away from the equilibrium internuclear separation of the molecule. The series representation of the potentials of weakly bound molecules are examined in more detail. The ground states of BeAr/sup +/, HeNe/sup +/, NaAr, and Ar/sub 2/ and the excited states of HeNe+, NaNe, and NaAr are best described by the Thakkar expansion. Finally, the observation of laser-assisted excitive Penning ionization in a flowing afterglow is reported. The reaction Ar(/sup 3/P/sub 2/) + Ca + h nu ..-->.. Ar + Ca/sup +/(5p /sup 2/P/sub J/) + e/sup -/ occurs when the photon energy, h nu, is approximately equal to the energy difference between the metastable argon and one of the fine structure levels of the ion's doublet. By monitoring the cascade fluorescence of the above reaction and comparing it to the flourescence from the field-free process Ar(/sup 3/P/sub 2/) + Ca ..-->.. Ar + Ca/sup +/(4p /sup 2/P/sub J/) + e/sup -/ a surprisingly large cross section of 6.7 x 10/sup 3/ A/sup 2/ is estimated.
NASA Astrophysics Data System (ADS)
Kim, Seung-Joon
Ab initio quantum mechanical studies have been performed to investigate the electronic structures and spectroscopic properties of small molecules and weakly bound complexes. A brief introduction to the theory applied is contained in Chapter 1. In Chapter 2, the structural discrepancy concerning the excited singlet ^1B _1 state of dichlorocarbene (CCl _2) has been explained using high levels of electron correlation and large basis sets. The most reliable values predicted here for the CCl_2 bond distances are r_0 = 1.713 A (^1A_1) and r_0 = 1.657 A (^1 B_1), which are in excellent agreement with the preferred experiments. Molecular structures, vibrational frequencies and energetics of phenylnitrene (PhN) are presented in Chapter 3. Geometries are optimized at the CISD level of theory with a DZ + d basis set. The theoretical ground state vibrational frequencies are used to assign the experimental IR spectrum for PhN. The S_0 state has the same orbital occupation as the ground triplet ^3A_2 state (T_0); i.e., it is the open-shell singlet ^1A_2 state. The singlet-triplet energy separation is predicted to be 17.7 kcal/mol and the lowest singlet state is structurally remarkably different from the ground state. The first excited triplet state (T_1) of PhN is predicted to be highly puckered with a T_0 -T_1 transition energy of 18 600 cm^{-1} and a barrier to planarity of 8000 cm^{-1}. Chapter 4 contains an application of quantum mechanical techniques to the potential energy surfaces for the singlet and triplet CH_3P to CH_2PH rearrangement. The geometry optimizations are performed at the CISD level of theory with the TZ2P + f basis set. For the closed -shell singlet state of CH_2 = PH, the highest level applied is CCSD with the TZ2P basis. The lowest singlet state of CH_3P is described using the two-configuration (TC) SCF method. The lowest excited singlet and triplet states of CH _3P are subject to Jahn-Teller distortions and thus exhibit C_{rm s} rather than C_{rm 3v
Perspectives of mothers with substance use problems on father involvement.
Gearing, Robin E; Selkirk, Enid K; Koren, Gideon; Leslie, Margaret; Motz, Mary; Zelazo, Laurel B; McNeill, Ted; Lozier, Fernand A
2008-01-01
A number of complex factors contribute to pregnant and parenting women's alcohol and substance use. To date, little research has focused on the implications, meaning and experiences of father involvement on mothers with substance use problems. The current study explores the experiences of mothers with substance use problems with respect to the role, impact and meaning of father involvement. This study conducted two focus groups utilizing a phenomenological approach. Mothers receiving clinical services at a comprehensive, community based program serving pregnant and parenting women with substance use problems were recruited to participate in this research. The meaning of father involvement among this group of women centered on four dimensions: emotional support, financial contributions to the family, amount and quality of time spent with the children and the family, and was dependent upon the particular expectations of the mother involved. Barriers and influences of father involvement were identified. The nature of father involvement had negative and positive impacts on participants. Maternal use of alcohol is a complex issue, one factor often ignored in father involvement. For mothers with substance use problems father involvement has a number of implications, both positive and negative.
Hagino, K.; Sagawa, H.
2011-07-15
We investigate the spatial extension of weakly bound Ne and C isotopes by taking into account the pairing correlation with the Hartree-Fock-Bogoliubov (HFB) method and a three-body model, respectively. We show that the odd-even staggering in the reaction cross sections of {sup 30,31,32}Ne and {sup 14,15,16}C are successfully reproduced, and thus the staggering can be attributed to the pairing anti-halo effect. A correlation between a one-neutron separation energy and the anti-halo effect is demonstrated for s and p waves using the HFB wave functions.
Parent Involvement, Emotional Support, and Behavior Problems: An Ecological Approach
ERIC Educational Resources Information Center
McCormick, Meghan P.; Cappella, Elise; O'Connor, Erin E.; McClowry, Sandee G.
2013-01-01
We examined relations between parent involvement and kindergarten students' behavior problems in classrooms with varying levels of teacher emotional support. Multi-informant data were collected on "n" = 255 low-income Black and Hispanic students, and "n" = 60 kindergarten classrooms in the baseline year of an intervention…
Parent Involvement, Emotional Support, and Behavior Problems: An Ecological Approach
ERIC Educational Resources Information Center
McCormick, Meghan P.; Cappella, Elise; O'Connor, Erin E.; McClowry, Sandee G.
2013-01-01
We examined relations between parent involvement and kindergarten students' behavior problems in classrooms with varying levels of teacher emotional support. Multi-informant data were collected on "n" = 255 low-income Black and Hispanic students, and "n" = 60 kindergarten classrooms in the baseline year of an intervention…
Bobkov, A A; Reisler, E
2000-01-01
Myosin subfragment 1 (S1) with SH1 (Cys(707)) and SH2 (Cys(697)) groups cross-linked by p-phenylenedimaleimide (pPDM-S1) is thought to be an analog of the weakly bound states of myosin bound to actin. The structural properties of pPDM-S1 were compared in this study to those of S1.ADP.BeF(x) and S1.ADP.AlF(4)(-), i.e., the established structural analogs of the myosin weakly bound states. To distinguish between the conformational effects of SH1-SH2 cross-linking and those due to their monofunctional modification, we used S1 with the SH1 and SH2 groups labeled with N-phenylmaleimide (NPM-S1) as a control in our experiments. The state of the nucleotide pocket was probed using a hydrophobic fluorescent dye, 3-[4-(3-phenyl-2-pyrazolin-1-yl)benzene-1-sulfonylamido]phen ylboronic acid (PPBA). Differential scanning calorimetry (DSC) was used to study the thermal stability of S1. By both methods the conformational state of pPDM-S1 was different from that of unmodified S1 in the S1.ADP.BeF(x) and S1.ADP.AlF(4)(-) complexes and closer to that of nucleotide-free S1. Moreover, BeF(x) and AlF(4)(-) binding failed to induce conformational changes in pPDM-S1 similar to those observed in unmodified S1. Surprisingly, when pPDM cross-linking was performed on S1.ADP.BeF(x) complex, ADP.BeF(x) protected to some extent the nucleotide pocket of S1 from the effects of pPDM modification. NPM-S1 behaved similarly to pPDM-S1 in our experiments. Overall, this work presents new evidence that the conformational state of pPDM-S1 is different from that of the weakly bound state analogs, S1.ADP.BeF(x) and S1.ADP.AlF(4)(-). The similar structural effects of pPDM cross-linking of SH1 and SH2 groups and their monofunctional labeling with NPM are ascribed to the inhibitory effects of these modifications on the flexibility/mobility of the SH1-SH2 helix. PMID:10866971
LaPlante, Debi A; Nelson, Sarah E; Gray, Heather M
2014-06-01
The "involvement effect" refers to the finding that controlling for gambling involvement often reduces or eliminates frequently observed game-specific associations with problem gambling. In other words, broader patterns of gambling behavior, particularly the number of types of games played over a defined period, contribute more to problem gambling than playing specific games (e.g., lottery, casino, Internet gambling). This study extends this burgeoning area of inquiry in three primary ways. First, it tests independently and simultaneously the predictive power of two gambling patterns: breadth involvement (i.e., the number of games an individual plays) and depth involvement (i.e., the number of days an individual plays). Second, it includes the first involvement analyses of actual betting activity records that are associated with clinical screening information. Third, it evaluates and compares the linearity of breadth and depth effects. We conducted analyses of the actual gambling activity of 1,440 subscribers to the bwin.party gambling service who completed an online gambling disorder screen. In all, 11 of the 16 games we examined had a significant univariate association with a positive screen for gambling disorder. However, after controlling for breadth involvement, only Live Action Internet sports betting retained a significant relationship with potential gambling-related problems. Depth involvement, though significantly related to potential problems, did not impact game-based gambling disorder associations as much as breadth involvement. Finally, breadth effects appeared steeply linear, with a slight quadratic component manifesting beyond four games played, but depth effects appeared to have a strong linear component and a slight cubic component.
Pietrow, M; Gagoś, M; Misiak, L E; Kornarzyński, K; Szurkowski, J; Rochowski, P; Grzegorczyk, M
2015-02-14
It is generally assumed that weakly bound (trapped) electrons in organic solids come only from radiolytical (or photochemical) processes like ionization caused by an excited positron entering the sample. This paper presents evidence for the presence of these electrons in non-irradiated samples of docosane. This can be due to the triboelectrification process. We argue that these electrons can be located (trapped) either in interlamellar gaps or in spaces made by non-planar conformers. Electrons from the former ones are bound more weakly than electrons from the latter ones. The origin of Vis absorption for the samples is explained. These spectra can be used as a probe indicating differences in the solid structures of hydrocarbons.
NASA Astrophysics Data System (ADS)
Yu, N.; Zhang, H. Q.; Jia, H. M.; Zhang, S. T.; Ruan, M.; Yang, F.; Wu, Z. D.; Xu, X. X.; Bai, C. L.
2010-07-01
The elastic scattering angular distributions of the weakly bound 9Be projectile from 208Pb and 209Bi have been measured for 14 beam energies near the threshold from 37 to 50 MeV. The parameters of the optical potential are extracted by means of phenomenological optical model analysis with PTOLEMY. Both of the systems show unusual potential behavior in the vicinity of the Coulomb barrier that the strength of the imaginary (absorptive) part of the potential is increasing (rather than decreasing) with decreasing energy, which is quite different from the results of some previous reports. This unusual threshold phenomenon indicates that the breakup channel is strongly coupled with the elastic channel and has obvious effects on the optical potential. The analyses also show that high precision elastic scattering angular distributions, especially those below the Coulomb barrier, are very important for extracting correct threshold behavior of the optical potential.
Beck, C.; Keeley, N.
2007-05-15
The influence on fusion of coupling to the breakup process is investigated for reactions where at least one of the colliding nuclei has a sufficiently low binding energy for breakup to become an important process. Elastic scattering, excitation functions for sub- and near-barrier fusion cross sections, and breakup yields are analyzed for {sup 6,7}Li+{sup 59}Co. Continuum-discretized coupled-channels (CDCC) calculations describe well the data at and above the barrier. Elastic scattering with {sup 6}Li (as compared to {sup 7}Li) indicates the significant role of breakup for weakly bound projectiles. A study of {sup 4,6}He induced fusion reactions with a three-body CDCC method for the {sup 6}He halo nucleus is presented. The relative importance of breakup and bound-state structure effects on total fusion is discussed.
Pietrow, M. Misiak, L. E.; Gagoś, M.; Kornarzyński, K.; Szurkowski, J.; Grzegorczyk, M.; Rochowski, P.
2015-02-14
It is generally assumed that weakly bound (trapped) electrons in organic solids come only from radiolytical (or photochemical) processes like ionization caused by an excited positron entering the sample. This paper presents evidence for the presence of these electrons in non-irradiated samples of docosane. This can be due to the triboelectrification process. We argue that these electrons can be located (trapped) either in interlamellar gaps or in spaces made by non-planar conformers. Electrons from the former ones are bound more weakly than electrons from the latter ones. The origin of Vis absorption for the samples is explained. These spectra can be used as a probe indicating differences in the solid structures of hydrocarbons.
Structuring a quantum solvent around a weakly bound dopant: the He-Cs2(3Sigma(u)) complex.
Prosmiti, Rita; Delgado-Barrio, Gerardo; Villarreal, Pablo; Yurtsever, Ersin; Coccia, Emanuele; Gianturco, Franco A
2009-12-31
The structure and energetics of (3,4)HeCs(2)((3)Sigma(u)) molecules are analyzed from first principles. Fixing the cesium dimer at its equilibrium distance, the electronic structure was determined through ab initio methods at the CCSD(T) level of theory using a large basis set to compute the interaction energies. At the T-shaped geometry, there is a shallow well with a depth of approximately 2 cm(-1) placed at R approximately 6.75 A, R being the distance from the center of mass of Cs(2) to He. That depth gradually decreases to approximately 0.75 cm(-1), while R increases to about 11.5 A at linear arrangements. A simple model of adding atom-atom Lennard-Jones potentials with well-depth and equilibrium distance parameters depending on the angular orientation was found to accurately reproduce the ab initio points. Using this analytical form, variational calculations at zero total angular momentum are performed, predicting a single bound level at approximately -0.106 (approximately -0.042) cm(-1) for the boson (fermion) species. Further calculations using Quantum Monte Carlo methods are carried out and found to be in good agreement with the variational ones. On the basis of the present results, such analytical expression could in turn be used to describe the structure and binding of larger complexes and therefore opens the possibility to further studies involving such aggregates.
Involvement of the prefrontal cortex in problem solving.
Mushiake, Hajime; Sakamoto, Kazuhiro; Saito, Naohiro; Inui, Toshiro; Aihara, Kazuyuki; Tanji, Jun
2009-01-01
To achieve a behavioral goal in a complex environment, such as problem-solving situations, we must plan multiple steps of action. On planning a series of actions, we anticipate future events that will occur as a result of each action, and mentally organize the temporal sequence of events. To investigate the involvement of the lateral prefrontal cortex (PFC) in such multistep planning, we examined neuronal activity in the PFC while monkeys performed a maze path-finding task. In this task, we set monkeys the job of capturing a goal in the maze by moving a cursor on the screen. Cursor movement was linked to movements of each wrist. To dissociate the outcomes of the intended action from the motor commands, we trained the monkeys to use three different hand-cursor assignments. We found that monkeys were able to perform this task in a flexible manner. This report first introduces a problem-solving framework for studying the function of the PFC, from the view point of cognitive science. Then, this chapter will cover the neuronal representation of a series of actions, goal subgoal transformation, and synchrony of PFC neurons. We reported PFC neurons reflected final goals and immediate goals during the preparatory period. We also found some PFC neurons reflected each of all forthcoming steps of actions during the preparatory period and increased their activity step by step during the execution period. Recently, we found that the transient increase in synchronous activity of PFC neurons was involved in goal subgoal transformations. Our data suggest that the PFC is involved primarily in the dynamic representation of multiple future events that occur as a consequence of behavioral actions in problem-solving situations.
Experimental quantum annealing: case study involving the graph isomorphism problem.
Zick, Kenneth M; Shehab, Omar; French, Matthew
2015-06-08
Quantum annealing is a proposed combinatorial optimization technique meant to exploit quantum mechanical effects such as tunneling and entanglement. Real-world quantum annealing-based solvers require a combination of annealing and classical pre- and post-processing; at this early stage, little is known about how to partition and optimize the processing. This article presents an experimental case study of quantum annealing and some of the factors involved in real-world solvers, using a 504-qubit D-Wave Two machine and the graph isomorphism problem. To illustrate the role of classical pre-processing, a compact Hamiltonian is presented that enables a reduced Ising model for each problem instance. On random N-vertex graphs, the median number of variables is reduced from N(2) to fewer than N log2 N and solvable graph sizes increase from N = 5 to N = 13. Additionally, error correction via classical post-processing majority voting is evaluated. While the solution times are not competitive with classical approaches to graph isomorphism, the enhanced solver ultimately classified correctly every problem that was mapped to the processor and demonstrated clear advantages over the baseline approach. The results shed some light on the nature of real-world quantum annealing and the associated hybrid classical-quantum solvers.
Experimental quantum annealing: case study involving the graph isomorphism problem
Zick, Kenneth M.; Shehab, Omar; French, Matthew
2015-01-01
Quantum annealing is a proposed combinatorial optimization technique meant to exploit quantum mechanical effects such as tunneling and entanglement. Real-world quantum annealing-based solvers require a combination of annealing and classical pre- and post-processing; at this early stage, little is known about how to partition and optimize the processing. This article presents an experimental case study of quantum annealing and some of the factors involved in real-world solvers, using a 504-qubit D-Wave Two machine and the graph isomorphism problem. To illustrate the role of classical pre-processing, a compact Hamiltonian is presented that enables a reduced Ising model for each problem instance. On random N-vertex graphs, the median number of variables is reduced from N2 to fewer than N log2 N and solvable graph sizes increase from N = 5 to N = 13. Additionally, error correction via classical post-processing majority voting is evaluated. While the solution times are not competitive with classical approaches to graph isomorphism, the enhanced solver ultimately classified correctly every problem that was mapped to the processor and demonstrated clear advantages over the baseline approach. The results shed some light on the nature of real-world quantum annealing and the associated hybrid classical-quantum solvers. PMID:26053973
[Adolescents previously involved in Satanism: mental health problems experience].
Heathcote, H; Gmeiner, A; Poggenpoel, M
1998-03-01
As far as the phenomena of adolescents previously involved with satanism that experience obstacles in the strive for mental health, no research has previously been done. Adolescents previously involved in satanism, presents behaviour problems like aggressive outbursts depression, "psychosis", or suicide attempts that can even lead to suicide. In the phenomena-analysis semi-structured, phenomenological interviews with the respondents and their parents, were performed. The respondents were requested to write a naive sketch about there life. After the data-control was done, guidelines for nursing staff had been set. The guidelines are set for the management of adolescents that has previously been involved in satanism, and experiences obstacles in their strive for mental health. Interviews with experts in satanism was done, literature in the form of books, magazines and newsclippings were used to verify the findings in the research. The most important guidelines are that: the caregivers have to be reborn Christians; they are not allowed to show, any fear or sympathy; they have to have sufficient knowledge about satanism; the adolescent has to be unconditionally accepted; the caregivers have to work in a team; the adolescents have to be taught to deal with their emotions.
Adolescents previously involved in Satanism experiencing mental health problems.
Heathcote, H; Gmeiner, A; Poggenpoel, M
1999-06-01
No research has previously been done regarding the phenomenon of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Adolescents previously involved in Satanism present behavioral problems like aggressive outbursts, depression, "psychosis" or suicide attempts, that could lead to suicide. In the phenomenon-analysis semi-structured, phenomenological interviews were performed with the respondents and their parents. The respondents were requested to write a naïve sketch about their life. After completion of the data-control, guidelines for nursing staff were set. The guidelines are set for the management of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Interviews with experts in Satanism were conducted, literature in the form of books, magazines and newspaper-clippings were used to verify the research findings. The most important guidelines are that the caregivers have to be reborn Christians; they are not allowed to show any fear or sympathy; they must have sufficient knowledge about Satanism; the adolescents have to be unconditionally accepted; the caregivers have to work in a team and the adolescents have to be taught to deal with their emotions.
NASA Astrophysics Data System (ADS)
Yang, Y. Y.; Liu, X.; Pang, D. Y.
2016-09-01
Experimental data show that the elastic scattering cross sections of the neutron-rich nucleus 11Be are greatly reduced by the coupling effects from the breakup channels, while those of the proton-rich nucleus 8B are not. Such difference is found to persist in results of systematic calculations of 8B elastic scattering from 208Pb at 60 and 170.3 MeV and from 64Zn at 32 and 86 MeV, and 11Be elastic scattering from 208Pb at 55 and 143 MeV and from 64Zn at 29 and 66 MeV with the continuum-discretized coupled channel (CDCC) method. The Coulomb and centrifugal barriers experienced by the valence proton in the ground state of 8B, which do not exist for the valence neutron in the ground state of 11Be, are found to be the reason for such differences in the angular distributions of elastic scattering cross sections of these two weakly bound nuclei.
Lebedev, V. S. Narits, A. A.
2013-10-15
Ion-pair formation processes are studied in collisions of Rydberg atoms with neutral particles possessing small electron affinities. Nonadiabatic transitions from a Rydberg covalent term to an ionic term of a quasi-molecule are considered using the modified Landau-Zener theory supplemented with calculation of survival factors of an anion decaying in the Coulomb field of a positive ion core. Using the technique of irreducible tensor operators and the momentum representation of the wavefunction of a highly excited atom, exact expressions are obtained for transition matrix elements and the ionic-covalent coupling parameter. The approach developed in the paper provides the description beyond the scope of a conventional assumption about a small variation of the wavefunction of the Rydberg atom on the range of electron coordinates determined by the characteristic radius of the wavefunction of the anion. This allows one to correctly consider long-range effects of the interaction between a weakly bound electron and the neutral core of a negative ion in processes under study. It is shown by the example of thermal collisions of Xe(nf) atoms with CH{sub 3}CN molecules that this is very important for a reliable quantitative description of anion formation with a low binding energy. The results are compared with experiments and calculations performed within the framework of a number of approximate methods.
NASA Astrophysics Data System (ADS)
Dewberry, Christopher T.; Mueller, Jessica L.; Mackenzie, Rebecca B.; Timp, Brooke A.; Marshall, Mark D.; Leung, Helen O.; Leopold, Kenneth R.
2017-10-01
The weakly bound complex formed from CO2 and 2,6-difluoropyridine (2,6-DFP) has been observed by chirped pulse and conventional cavity Fourier transform microwave spectroscopy. As in the related complexes with pyridine and 3,5-difluoropyridine, the carbon of the CO2 approaches the nitrogen of the heterocycle in the plane of the ring. However, the CO2-2,6-DFP complex is found to differ from the pyridine and 3,5-DFP analogues in several respects. First, the data indicate that the N⋯C weak bond distance is 2.9681(32) Å, a value that is ∼0.17 Å longer than that previously determined for CO2-pyridine (2.798 Å) and 0.14 Å longer than that in CO2-3,5-difluoropyridine (2.825 Å). Second, unlike the pyridine and 3,5-difluoropyridine complexes, the CO2 oxygens in CO2-2,6-DFP do not lie in the plane of the ring, i.e., fluorination of the pyridine in the ortho positions causes the CO2 to rotate 90° out of plane. Moreover, the observed rotational constants indicate that the CO2 moiety undergoes large amplitude vibrational motion with an average bending amplitude of ∼31° off this perpendicular geometry. Third, M06-2X/6-311++G(3df,3pd) and MP2/6-311++G(3df,3pd) calculations both indicate that in the equilibrium configuration, the carbon of the CO2 is displaced from the C2 axis of the 2,6-DFP such that axis forms an angle of 20-23° with the line joining the nitrogen and the CO2 carbon. The current results support the previous conjecture that the anomalously short N⋯C distances in CO2-pyridine and CO2-3,5-difluoropyridine result from secondary attractive interactions between the oxygen atoms and the ortho hydrogens. These interactions are eliminated in the 2,6-DFP system by fluorination in the ortho positions, causing the weak bond distance to increase and the CO2 to rotate out of the plane.
ERIC Educational Resources Information Center
Kirkhaug, Bente; Drugli, May Britt; Klockner, Christian A.; Morch, Willy-Tore
2013-01-01
The present study examined the factor structure of the Teacher Involvement Questionnaire (Involve-T) by means of exploratory factor analysis and examined the association between children's socio-emotional and behavioural problems and teacher-reported parental involvement in school, using structural equation modelling. The study was conducted with…
NASA Astrophysics Data System (ADS)
Lin, Shih-Yin; Singh, Chandralekha
2015-12-01
It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong alternative conceptions correctly, appropriate scaffolding support can be helpful. The goal of this study is to examine how different scaffolding supports involving analogical problem-solving influence introductory physics students' performance on a target quantitative problem in a situation where many students' solution process is derailed due to alternative conceptions. Three different scaffolding supports were designed and implemented in calculus-based and algebra-based introductory physics courses involving 410 students to evaluate the level of scaffolding needed to help students learn from an analogical problem that is similar in the underlying principles involved but for which the problem-solving process is not derailed by alternative conceptions. We found that for the quantitative problem involving strong alternative conceptions, simply guiding students to work through the solution of the analogical problem first was not enough to help most students discern the similarity between the two problems. However, if additional scaffolding supports that directly helped students examine and repair their knowledge elements involving alternative conceptions were provided, e.g., by guiding students to contemplate related issues and asking them to solve the targeted problem on their own first before learning from the analogical problem provided, students were more likely to discern the underlying similarities between the problems and avoid getting derailed by alternative conceptions when solving the targeted problem. We also found that some scaffolding supports were more effective in the calculus-based course than in the algebra
Jouriles, Ernest N; Rosenfield, David; McDonald, Renee; Mueller, Victoria
2014-01-01
This study examined whether child involvement in interparental conflict predicts child externalizing and internalizing problems in violent families. Participants were 119 families (mothers and children) recruited from domestic violence shelters. One child between the ages of 7 and 10 years in each family (50 female, 69 male) completed measures of involvement in their parents' conflicts, externalizing problems, and internalizing problems. Mothers completed measures of child externalizing and internalizing problems, and physical intimate partner violence. Measures were completed at three assessments, spaced 6 months apart. Results indicated that children's involvement in their parents' conflicts was positively associated with child adjustment problems. These associations emerged in between-subjects and within-subjects analyses, and for child externalizing as well as internalizing problems, even after controlling for the influence of physical intimate partner violence. In addition, child involvement in parental conflicts predicted later child reports of externalizing problems, but child reports of externalizing problems did not predict later involvement in parental conflicts. These findings highlight the importance of considering children's involvement in their parents' conflicts in theory and clinical work pertaining to high-conflict families.
Metzger, Aaron; Dawes, Nickki; Mermelstein, Robin; Wakschlag, Lauren
2010-01-01
Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1,040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24 months) enriched for smoking experimentation (83% had tried smoking). A structural equation model tested longitudinal paths between three categories of involvement (team sports, school clubs and activities, and religious activities, measured at baseline and 15 months), problem peer associations (baseline and 15 months), and cigarette smoking behavior (baseline and 24 months). Multi-group analyses indicated pathways differed by type of activity and adolescent gender. Boys’ baseline team sports and religious involvement predicted lower levels of smoking at 24 months via continued activity involvement at 15 months. Girls’ involvement in school clubs and activities and religious activities indirectly predicted lower levels of smoking at 24 months via reduced exposure to problem peers at 15 months. PMID:21603061
Family Involvement in Preschool Education: Rationale, Problems and Solutions for the Participants
ERIC Educational Resources Information Center
Kocyigit, Sinan
2015-01-01
This aim of this study is to examine the views of teachers, administrators and parents about the problems that emerge during family involvement in preschool activities and solutions for these problems. The participants were 10 teachers, 10 parents and 10 administrators from 4 preschools and 6 kindergartens in the Palandöken and Yakutiye districts…
ERIC Educational Resources Information Center
Locke, Benjamin D.; Mahalik, James R.
2005-01-01
Male sexual aggression toward women is a serious social problem, particularly on college campuses. In this study, college men's sexually aggressive behavior and rape myth acceptance were examined using conformity to 11 masculine norms and 2 variables previously linked to sexual aggression: problem drinking and athletic involvement. Results…
ERIC Educational Resources Information Center
Lin, Shih-Yin; Singh, Chandralekha
2015-01-01
It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong…
ERIC Educational Resources Information Center
Lin, Shih-Yin; Singh, Chandralekha
2015-01-01
It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong…
Problem Solving Process Research of Everyone Involved in Innovation Based on CAI Technology
NASA Astrophysics Data System (ADS)
Chen, Tao; Shao, Yunfei; Tang, Xiaowo
It is very important that non-technical department personnel especially bottom line employee serve as innovators under the requirements of everyone involved in innovation. According the view of this paper, it is feasible and necessary to build everyone involved in innovation problem solving process under Total Innovation Management (TIM) based on the Theory of Inventive Problem Solving (TRIZ). The tools under the CAI technology: How TO mode and science effects database could be very useful for all employee especially non-technical department and bottom line for innovation. The problem solving process put forward in the paper focus on non-technical department personnel especially bottom line employee for innovation.
Paternal ADHD Symptoms and Child Conduct Problems: Is Father Involvement Always Beneficial?
Romirowsky, Abigail Mintz; Chronis-Tuscano, Andrea
2013-01-01
Background Maternal psychopathology robustly predicts poor developmental and treatment outcomes for children with attention-deficit/hyperactivity disorder (ADHD). Despite the high heritability of ADHD, few studies have examined associations between paternal ADHD symptoms and child adjustment, and none have also considered degree of paternal involvement in childrearing. Identification of modifiable risk factors for child conduct problems is particularly important in this population given the serious adverse outcomes resulting from this comorbidity. Methods This cross-sectional study examined the extent to which paternal involvement in childrearing moderated the association between paternal ADHD symptoms and child conduct problems among 37 children with ADHD and their biological fathers. Results Neither paternal ADHD symptoms nor involvement was independently associated with child conduct problems. However, the interaction between paternal ADHD symptoms and involvement was significant, such that paternal ADHD symptoms were positively associated with child conduct problems only when fathers were highly involved in childrearing. Conclusions The presence of adult ADHD symptoms may determine whether father involvement in childrearing has a positive or detrimental influence on comorbid child conduct problems. PMID:25250402
Dasso, C. H.; Vitturi, A.
2009-06-15
We exploit a model describing the breakup of weakly bound nuclei that can be used as a laboratory for testing different prescriptions that have been advanced in the literature to take into account the nearby presence of continuum states. In the model, we follow the evolution of a single-particle wave function in one dimension, initially bound by a Woods-Saxon type potential and then perturbed by a time- and position-dependent external field. Proper choices of this potential can simulate the effect of the interaction between reaction partners in a nuclear collision. These processes generate inelastic excitation probabilities that--distributed over the bound and continuum states of the system--lead to either a partial or a total fragmentation of the final wave function.
Finite element simulations involving simultaneous multiple interface fronts in phase change problems
NASA Technical Reports Server (NTRS)
Ouyang, Tianhong; Tamma, Kumar K.
1992-01-01
The present paper describes the simulation of phase change problems involving simultaneous multiple interface fronts employing the finite element method. Much of the past investigations employing finite elements have been restricted to primarily a single phase change situation. The existence of more than one phase, that is, the presence of multiple phase fronts poses certain challenges and further complications. However, the results provide a very interesting thermal behavior for this class of problems. In this paper, attention is focused on fixed grid methods and the trapezoidal family of one-step methods using the enthalpy formulations. Illustrative examples which handle simultaneous multiple fronts in phase change problems are presented.
ERIC Educational Resources Information Center
Ybrandt, Helene
2010-01-01
The aim of the study was to examine risk and vulnerability factors contributing to problems with alcohol use in adolescence. Data relating to seven life areas (medical status, school status, social relationships, family background and relationships, psychological functioning, legal involvement, and alcohol use) was gathered using the ADAD…
Concurrent Mental Health and Substance Use Problems among Street-Involved Youth
ERIC Educational Resources Information Center
Kirst, Maritt; Frederick, Tyler; Erickson, Patricia G.
2011-01-01
Among marginalized populations, homeless adults are known to have elevated rates of mental health and substance use problems compared to the general population, but less is known about their youthful homeless counterparts. While few studies currently exist, what research has been conducted among street-involved youth has confirmed high rates of…
On the privacy problems involved in allowing access to computers via the public telephone system
NASA Astrophysics Data System (ADS)
Giess, S. C.
1988-04-01
Privacy problems involved in allowing access to computers over the Public Switched Telephone Network (PSTN) are discussed. The relevant aspects of current land-line PSTN and cellular radio operations are described and the weaknesses of the access controls of current computer systems are discussed. Possible solutions that would allow access under a limited set of conditions are described.
ERIC Educational Resources Information Center
Rigby, Ken; Slee, Phillip
1999-01-01
Results of self-reports and peer nomination procedures to identify bullies and victims indicated that involvement in bully-victim problems at school, especially for students with relatively little social support, was significantly related to degree of suicidal ideation. (Author/JDM)
ERIC Educational Resources Information Center
Farmer, Thomas W.; Irvin, Matthew J.; Motoca, Luci M.; Leung, Man-Chi; Hutchins, Bryan C.; Brooks, Debbie S.; Hall, Cristin M.
2015-01-01
Continuity and change in children's involvement in bullying was examined across the transition to middle school in relation to externalizing and internalizing behavior problems in fifth grade and peer affiliations in fifth and sixth grades. The sample consisted of 533 students (223 boys, 310 girls) with 72% European American, 25% African American,…
ERIC Educational Resources Information Center
Metzger, Aaron; Dawes, Nickki; Mermelstein, Robin; Wakschlag, Lauren
2011-01-01
Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24 months) enriched for smoking experimentation (83% had tried smoking). A structural equation model…
ERIC Educational Resources Information Center
Ihmeideh, Fathi; Khasawneh, Samer; Mahfouz, Safi; Khawaldeh, Moustafa
2008-01-01
This study aimed to investigate the problems facing parental involvement in Jordanian kindergartens from the parents' perspectives. A 36-item questionnaire that addressed five domains was designed by the researchers and distributed among the study participants. The study sample consisted of 297 parents of kindergarten children from various…
ERIC Educational Resources Information Center
Farmer, Thomas W.; Irvin, Matthew J.; Motoca, Luci M.; Leung, Man-Chi; Hutchins, Bryan C.; Brooks, Debbie S.; Hall, Cristin M.
2015-01-01
Continuity and change in children's involvement in bullying was examined across the transition to middle school in relation to externalizing and internalizing behavior problems in fifth grade and peer affiliations in fifth and sixth grades. The sample consisted of 533 students (223 boys, 310 girls) with 72% European American, 25% African American,…
ERIC Educational Resources Information Center
Metzger, Aaron; Dawes, Nickki; Mermelstein, Robin; Wakschlag, Lauren
2011-01-01
Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24 months) enriched for smoking experimentation (83% had tried smoking). A structural equation model…
Personifying self in physics problem situations involving forces as a student help strategy
NASA Astrophysics Data System (ADS)
Tabor-Morris, A. E.
2013-03-01
How can physics teachers best guide students regarding physics problem situations involving forces? A suggestion is made here to personify oneself as the object in question, that is, to pretend to be the object undergoing forces and then qualify and quantify those forces according to their vectors for the system at hand. This personification is not meant to empower the object to act, just to sense the forces it is experiencing. This strategy may be especially useful to beginning physics learners attacking problems that involve both multiple forces AND multiple objects, since each object acted upon needs to be considered separately, using the idea that one cannot be two places at once. An example of this type of problem expounded on here is Atwood's machine: two weights hung over a pulley with a single rope. Another example given is electromagnetic forces on one charge caused by other charges in the vicinity. Discussion is made on implementation of classroom strategies. Department of Physics
Psychiatric morbidity and people's experience of and response to social problems involving rights.
Balmer, Nigel J; Pleasence, Pascoe; Buck, Alexy
2010-11-01
Psychiatric morbidity has been shown to be associated with the increased reporting of a range of social problems involving legal rights ('rights problems'). Using a validated measure of psychiatric morbidity, this paper explores the relationship between psychiatric morbidity and rights problems and discusses the implications for the delivery of health and legal services. New representative national survey data from the English and Welsh Civil and Social Justice Survey (CSJS) surveyed 3040 adults in 2007 to explore the relationship between GHQ-12 scores and the self reported incidence of and behaviour surrounding, rights problems. It was found that the prevalence of rights problems increased with psychiatric morbidity, as did the experience of multiple problems. It was also found the likelihood of inaction in the face of problems increased with psychiatric morbidity, while the likelihood of choosing to resolve problems without help decreased. Where advice was obtained, psychiatric morbidity was associated with a greater tendency to obtain a combination of 'legal' and 'general' support, rather than 'legal' advice alone. The results suggest that integrated and 'outreach' services are of particular importance to the effective support of those facing mental illness.
NASA Astrophysics Data System (ADS)
Dringenberg, Emily A.
Engineers are expected to solve problems that are ill-structured. These problems are presented with a lack of necessary information and allow for different ways of engaging with the problem; they are open-ended and involve multiple possible solutions with multiple means of evaluation. In order to allow maximum time for students to develop skills for solving such problems, undergraduate engineering programs can introduce such problems during the first year of students' education, in the form of cornerstone design tasks. This provides students with more opportunities to develop their ability to engage with ill-structured problems, which are characteristic of engineering work. Researchers have documented variation within both the behavior and perceptions of students' early experiences with design problems. General themes include novice-like design behavior, discomfort with lack of information, difficulty with problem scoping, and resistance to ambiguity. To build on these generalizations of students' experiences, a more thorough understanding of the variation in how students experience this phenomenon of engaging with ill-structured problems is needed to design effective learning environments. This work presents the qualitatively different ways that engineering students experience problems with multiple possible solutions during their first year of engineering studies. Using phenomenography as the methodological framework, data were collected through in-depth, semi-structured interviews with 27 first-year engineering students. The iterative, phenomenographic analysis resulted in seven descriptive categories for the ways participants experienced problems involving multiple possible solutions. The names of these categories represent the different foci of the students' experiences: completion, transition, iteration, organization, collaboration, reasoning, and growth. These categories are organized along two crucial dimensions of variation: reaction to ambiguity and role
Narits, A. A.; Mironchuk, E. S.; Lebedev, V. S.
2013-10-15
Electron-transfer processes are studied in thermal collisions of Rydberg atoms with alkaline-earth Ca(4s{sup 2}), Sr(5s{sup 2}), and Ba(6s{sup 2}) atoms capable of forming negative ions with a weakly bound outermost p-electron. We consider the ion-pair formation and resonant quenching of highly excited atomic states caused by transitions between Rydberg covalent and ionic terms of a quasi-molecule produced in collisions of particles. The contributions of these reaction channels to the total depopulation cross section of Rydberg states of Rb(nl) and Ne(nl) atoms as functions of the principal quantum number n are compared for selectively excited nl-levels with l Much-Less-Than n and for states with large orbital quantum numbers l = n - 1, n - 2. It is shown that the contribution from resonant quenching dominates at small values of n, and the ion-pair formation process begins to dominate with increasing n. The values and positions of the maxima of cross sections for both processes strongly depend on the electron affinity of an alkaline-earth atom and on the orbital angular momentum l of a highly excited atom. It is shown that in the case of Rydberg atoms in states with large l {approx} n - 1, the rate constants of ion-pair formation and collisional quenching are considerably lower than those for nl-levels with l Much-Less-Than n.
NASA Astrophysics Data System (ADS)
Akopyan, M. E.; Baturo, V. V.; Lukashov, S. S.; Poretsky, S. A.; Pravilov, A. M.
2015-01-01
The stepwise three-step three-color laser population of the I2(β1g, νβ, Jβ) rovibronic states via the B0u+, νB, JB rovibronic states and rovibronic levels of the 1u(bb) and 0g+(bb) states mixed by hyperfine interaction is used for determination of rovibronic level energies of the weakly bound I2(1u(bb)) state. Dunham coefficients of the state, Yi0 (i = 0-3), Yi1 (i = 0-2), Y02 and Y12 for the {{v}{{1u}}} = 1-5, 8, 10, 15 and {{J}{{1u}}} ≈ 9-87 ranges, the dissociation energy of the state, De, and equilibrium I-I distance, Re, as well as the potential energy curve are determined. There are aperiodicities in the excitation spectrum corresponding to the β, νβ = 23, Jβ ← 1u(bb), ν1u = 4, 5, J1u progressions in the I2 + Rg = He, Ar mixture, namely, a great number of lines which do not coincide with the R or P line progressions. Their positions conflict with the ΔJ-even selection rule. Furthermore, they do not correspond to the ΔJ-odd progression.
A social marketing approach to involving Afghans in community-level alcohol problem prevention.
Cherry, L; Redmond, S P
1994-06-01
A program for preventing alcohol-related problems at the community level using environmentally-focused, public health approaches sought to involve a new segment of the community. That segment consisted of recently-immigrated Afghans from a traditionally abstinent culture. Social marketing research was employed to elicit value-based benefits to be used in promoting the product (involvement with environmental change efforts) to the target audience. While the channels of distribution for promotional messages were easily identified, special attention was required relative to effective spokespersons. Much was also learned about the immigration experience of Afghans in a San Francisco Bay Area community that has significance for other fields.
NASA Technical Reports Server (NTRS)
Tamma, Kumar K.; Railkar, Sudhir B.
1988-01-01
The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.
NASA Technical Reports Server (NTRS)
Tamma, Kumar K.; Railkar, Sudhir B.
1988-01-01
The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.
1984-09-01
A conformal transformation formula using Riemann-Stieltjes integrals is derived for use with problems involving the interaction between a given finite-sized geometry and a known far field. The derivative of this transformation is non-singular in the domain considered and tends to one at infinity. A formula is derived for transformation from the unit circle to the exterior of an arbitrarily given continuous curve with bounded variation . A special case of the transformation is very similar
Greater involvement and diversity of Internet gambling as a risk factor for problem gambling
Russell, Alex; Blaszczynski, Alex; Hing, Nerilee
2015-01-01
Background: Concerns that Internet gambling has elevated the prevalence of problem gambling have not been substantiated; however, evidence suggests a subgroup of Internet gamblers do experience higher rates of gambling harms. Greater overall involvement in gambling appears to be predictive of harms. The purpose of this study was to examine differences between Internet gamblers with a single or multiple online gambling accounts, including their gambling behaviours, factors influencing their online gambling and risk of experiencing gambling problems. Methods: Internet gamblers (3178) responding to an online survey that assessed their gambling behaviour, and use of single or multiple online gambling accounts. Results: Results revealed that multiple account holders were more involved gamblers, gambling on more activities and more frequently, and had higher rates of gambling problems than single account holders. Multiple account holders selected gambling sites based on price, betting options, payout rates and game experience, whereas single account holders prioritized legality and consumer protection features. Conclusion: Results suggest two different types of Internet gamblers: one motivated to move between sites to optimize preferred experiences with a tendency to gamble in a more volatile manner; and a smaller, but more stable group less influenced by promotions and experiences, and seeking a reputable and safe gambling experience. As the majority of Internet gamblers use multiple accounts, more universal responsible gambling strategies are needed to assist gamblers to track and control their expenditure to reduce risks of harm. PMID:25745873
Greater involvement and diversity of Internet gambling as a risk factor for problem gambling.
Gainsbury, Sally M; Russell, Alex; Blaszczynski, Alex; Hing, Nerilee
2015-08-01
Concerns that Internet gambling has elevated the prevalence of problem gambling have not been substantiated; however, evidence suggests a subgroup of Internet gamblers do experience higher rates of gambling harms. Greater overall involvement in gambling appears to be predictive of harms. The purpose of this study was to examine differences between Internet gamblers with a single or multiple online gambling accounts, including their gambling behaviours, factors influencing their online gambling and risk of experiencing gambling problems. Internet gamblers (3178) responding to an online survey that assessed their gambling behaviour, and use of single or multiple online gambling accounts. Results revealed that multiple account holders were more involved gamblers, gambling on more activities and more frequently, and had higher rates of gambling problems than single account holders. Multiple account holders selected gambling sites based on price, betting options, payout rates and game experience, whereas single account holders prioritized legality and consumer protection features. Results suggest two different types of Internet gamblers: one motivated to move between sites to optimize preferred experiences with a tendency to gamble in a more volatile manner; and a smaller, but more stable group less influenced by promotions and experiences, and seeking a reputable and safe gambling experience. As the majority of Internet gamblers use multiple accounts, more universal responsible gambling strategies are needed to assist gamblers to track and control their expenditure to reduce risks of harm. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
Dixon, Ramsay W; Youssef, George J; Hasking, Penelope; Yücel, Murat; Jackson, Alun C; Dowling, Nicki A
2016-07-01
Several factors are associated with an increased risk of adolescent problem gambling, including positive gambling attitudes, higher levels of gambling involvement, ineffective coping strategies and unhelpful parenting practices. It is less clear, however, how these factors interact or influence each other in the development of problem gambling behavior during adolescence. The aim of the current study was to simultaneously explore these predictors, with a particular focus on the extent to which coping skills and parenting styles may moderate the expected association between gambling involvement and gambling problems. Participants were 612 high school students. The data were analyzed using a zero-inflated Poisson (ZIP) regression model, controlling for gender. Although several variables predicted the number of symptoms associated with problem gambling, none of them predicted the probability of displaying any problem gambling. Gambling involvement fully mediated the relationship between positive gambling attitudes and gambling problem severity. There was a significant relationship between gambling involvement and problems at any level of problem focused coping, reference to others and inconsistent discipline. However, adaptive coping styles employed by adolescents and consistent disciplinary practices by parents were buffers of gambling problems at low levels of adolescent gambling involvement, but failed to protect adolescents when their gambling involvement was high. These findings indicate that research exploring the development of gambling problems is required and imply that coping and parenting interventions may have particular utility for adolescents who are at risk of development gambling problems but who are not gambling frequently. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Markopoulos, N.; Calise, A. J.
1993-01-01
The class of all piecewise time-continuous controllers tracking a given hypersurface in the state space of a dynamical system can be split by the present transformation technique into two disjoint classes; while the first of these contains all controllers which track the hypersurface in finite time, the second contains all controllers that track the hypersurface asymptotically. On this basis, a reformulation is presented for optimal control problems involving state-variable inequality constraints. If the state constraint is regarded as 'soft', there may exist controllers which are asymptotic, two-sided, and able to yield the optimal value of the performance index.
NASA Astrophysics Data System (ADS)
Zheng, Q.
2011-12-01
On the application of the genetic algorithm to the predictability problems involving "on-off" switches ZHENG Qin(1,2), DAI Yi(1), ZHANG Lu(1)and LU Xiaoqing(1) (1)Institute of Science, PLA University of Science and Technology, Nanjing 211101, China; (2)State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Abstract The lower bound of maximum predictable time can be formulated into a constrained nonlinear optimization problem, and the traditional solution to this problem is the filtering method and the conditional nonlinear optimal perturbation (CNOP) method. Usually, the CNOP method is implemented with the help of a gradient descent algorithm based on the adjoint method, which is named as the ADJ-CNOP, hereinafter. However, with the increasing improvement of actual prediction models, more and more physical processes are taken into consideration in models in the form of parameterization, thus giving rise to the "on-off" switch problem, which affects tremendously the effectiveness of the conventional gradient descent algorithm based on the adjoint method. This paper attempts to apply a genetic algorithm (GA) to the CNOP method, named as the GA-CNOP, to solve the predictability problems involving the "on-off" switches. As the precision of the filtering method depends uniquely on the division of the constraint region, its results are taken as benchmarks and a series of comparisons between the ADJ-CNOP and the GA-CNOP are performed. It is revealed that the GA-CNOP can always figure out the accurate lower bound of maximum predictable time even in discontinuous cases, while the ADJ-CNOP, owing to the effect of "on-off" switches, often yields the incorrect lower bound of maximum predictable time. This would suggest that in non-smooth cases, using a GA to solve the predictability problems is more effective than using the conventional
ERIC Educational Resources Information Center
Liu, Shuh Yun; And Others
This is a guide for teachers for coping with educational and behavior problems involving Indochinese students in American schools. Problems that might be expected and factors that contribute to problems are outlined, including: (1) language difficulty; (2) imitation behavior by Indochinese students; (3) effects of camp life; (4) intragroup…
NASA Technical Reports Server (NTRS)
Lenardic, A.; Kaula, W. M.
1993-01-01
Effective numerical treatment of multicomponent viscous flow problems involving the advection of sharp interfaces between materials of differing physical properties requires correction techniques to prevent spurious diffusion and dispersion. We develop a particular algorithm, based on modern shock-capture techniques, employing a two-step nonlinear method. The first step involves the global application of a high-order upwind scheme to a hyperbolic advection equation used to model the distribution of distinct material components in a flow field. The second step is corrective and involves the application of a global filter designed to remove dispersion errors that result from the advection of discontinuities (e.g., material interfaces) by high-order, minimally dissipative schemes. The filter introduces no additional diffusion error. Nonuniform viscosity across a material interface is allowed for by the implementation of a compositionally weighted-inverse interface viscosity scheme. The combined method approaches the optimal accuracy of modern shock-capture techniques with a minimal increase in computational time and memory. A key advantage of this method is its simplicity to incorporate into preexisting codes be they finite difference, element, or volume of two or three dimensions.
NASA Technical Reports Server (NTRS)
Lenardic, A.; Kaula, W. M.
1993-01-01
Effective numerical treatment of multicomponent viscous flow problems involving the advection of sharp interfaces between materials of differing physical properties requires correction techniques to prevent spurious diffusion and dispersion. We develop a particular algorithm, based on modern shock-capture techniques, employing a two-step nonlinear method. The first step involves the global application of a high-order upwind scheme to a hyperbolic advection equation used to model the distribution of distinct material components in a flow field. The second step is corrective and involves the application of a global filter designed to remove dispersion errors that result from the advection of discontinuities (e.g., material interfaces) by high-order, minimally dissipative schemes. The filter introduces no additional diffusion error. Nonuniform viscosity across a material interface is allowed for by the implementation of a compositionally weighted-inverse interface viscosity scheme. The combined method approaches the optimal accuracy of modern shock-capture techniques with a minimal increase in computational time and memory. A key advantage of this method is its simplicity to incorporate into preexisting codes be they finite difference, element, or volume of two or three dimensions.
Flouri, Eirini; Midouhas, Emily; Narayanan, Martina K
2016-07-01
This study investigated the cross-lagged relationship between father involvement and child problem behaviour across early-to-middle childhood, and tested whether temperament modulated any cross-lagged child behaviour effects on father involvement. It used data from the first four waves of the UK's Millennium Cohort Study, when children (50.3 % male) were aged 9 months, and 3, 5 and 7 years. The sample was 8302 families where both biological parents were co-resident across the four waves. Father involvement (participation in play and physical and educational activities with the child) was measured at ages 3, 5 and 7, as was child problem behaviour (assessed with the Strengths and Difficulties Questionnaire). Key child and family covariates related to father involvement and child problem behaviour were controlled. Little evidence was found that more father involvement predicted less child problem behaviour two years later, with the exception of father involvement at child's age 5 having a significant, but small, effect on peer problems at age 7. There were two child effects. More hyperactive children at age 3 had more involved fathers at age 5, and children with more conduct problems at age 3 had more involved fathers at age 5. Child temperament did not moderate any child behaviour effects on father involvement. Thus, in young, intact UK families, child adjustment appears to predict, rather than be predicted by, father involvement in early childhood. When children showed more problematic behaviours, fathers did not become less involved. In fact, early hyperactivity and conduct problems in children seemed to elicit more involvement from fathers. At school age, father involvement appeared to affect children's social adjustment rather than vice versa.
Exact image method for Gaussian beam problems involving a planar interface
NASA Technical Reports Server (NTRS)
Lindell, I. V.
1987-01-01
Exact image method, recently introduced for the solution of electromagnetic field problems involving sources above a planar interface or two homogeneous media, is shown to be valid also for sources located in complex space, which makes its application possible for Gaussian beam analysis. It is demonstrated that the Goos-Hanchen shift and the angular shift of a TE polarized beam are correctly given as asymptotic results by the exact reflection image theory. Also, the apparent image location giving the correct Gaussian beam transmitted through the interface is obtained as another asymptotic check. The present theory makes it possible to calculate the exact coupling from the Gaussian beam to the reflected and refracted beams, as well as to the surface wave.
NASA Technical Reports Server (NTRS)
Mclain, A. G.; Rao, C. S. R.
1976-01-01
A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.
Wu, Fan; Dioumaev, Vladimir K; Szalda, David J; Hanson, Jonathan; Bullock, R Morris
2007-09-24
The initial reaction observed between N-heterocyclic carbene IMes (IMes = 1,3-bis(2,4,6-trimethylphenyl)-imidazol-2-ylidene) and molybdenum and tungsten hydride complexes CpM(CO)_{2}(PPh_{3})H (M = Mo, W) is deprotonation of the metal hydride by IMes, giving [(IMes)H]^{+}[CpM(CO)_{2}(PPh_{3})]^{–} . At longer reaction times and higher temperatures, the reaction of IMes with CpM(CO)_{2}(PR_{3})H (M = Mo, W; R = Me, Ph) produces CpM(CO)_{2}(IMes)H. Hydride transfer from CpW(CO)_{2}(IMes)H to Ph_{3}C^{+}B(C_{6}F_{5})_{4}^{-} gives CpW(CO)_{2}(IMes)^{+}B(C_{6}F_{5})_{4}^{-} which was crystallographically characterized using x-ray radiation from a synchrotron. The IMes is bonded as a bidentate ligand, through the carbon of the carbene as well as forming a weak bond from the metal to a C_{=}C bond of one mesityl ring. The weakly bound C_{=}C ligand is hemilabile, being readily displaced by H_{2}, THF, ketones or alcohols. Reaction of CpW(CO)_{2}(IMes)^{+} with H_{2} gives the dihydride complex [CpW(CO)_{2}(IMes)(H)_{2}]^{+}. Addition of Et_{2}CH–OH to CpW(CO)_{2}(IMes)^{+}B(C_{6}F_{5})_{4}^{-} gives the alcohol complex [CpM(CO)_{2}(IMes)(Et_{2}CH–OH)]^{+}[B(C_{6}F_{5})_{4}]^{–} which was characterized by crystallography and exhibits no evidence for hydrogen bonding of the bound OH group. Addition of H_{2} to the ketone complex [CpW(CO)_{2}(IMes)(Et_{2}C_{=}O)]^{+}[B(C_{6}F_{5})_{4}]^{–} produces an equilibrium with the dihydride [CpW(CO)_{2}(IMes)(H)_{2}]^{+} (K_{eq} = 1.1 x 103 at 25 °C). The tungsten
Wu,F.; Dioumaev, V.; Szalda, D.; Hanson, J.; Bullock, R.
2007-01-01
The initial reaction observed between the N-heterocyclic carbene IMes (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) and molybdenum and tungsten hydride complexes CpM(CO){sub 2}(PPh{sub 3})H (M = Mo, W) is deprotonation of the metal hydride by IMes, giving [(IMes)H]{sup +}[CpM(CO){sub 2}(PPh{sub 3})]{sup -}. At longer reaction times and higher temperatures, the reaction of IMes with CpM(CO){sub 2}(PR{sub 3})H (M = Mo, W; R = Me, Ph) produces CpM(CO){sub 2}(IMes)H. Hydride transfer from CpW(CO)2(IMes)H to Ph{sub 3}C{sub +}B(C{sub 6}F{sub 5}){sub 4}{sup -} gives CpW(CO){sub 2}(IMes){sup +}B(C{sub 6}F{sub 5}){sub 4}{sup -}, which was crystallographically characterized using X-ray radiation from a synchrotron. The IMes is bonded as a bidentate ligand, through the carbon of the carbene as well as forming a weak bond from the metal to a C=C bond of one mesityl ring. The weakly bound C=C ligand is hemilabile, being readily displaced by H{sub 2}, THF, ketones, or alcohols. Reaction of CpW(CO){sub 2}(IMes){sup +} with H{sub 2} gives the dihydride complex [CpW(CO){sub 2}(IMes)(H){sub 2}]{sup +}. Addition of Et{sub 2}CH-OH to CpW(CO){sub 2}(IMes){sup +}B(C{sub 6}F{sub 5}){sub 4}{sup -} gives the alcohol complex [CpW(CO){sub 2}(IMes)(Et{sub 2}CH-OH)]{sup +}[B(C{sub 6}F{sub 5}){sub 4}]{sup -}, which was characterized by crystallography and exhibits no evidence for hydrogen bonding of the bound OH group. Addition of H{sub 2} to the ketone complex [CpW(CO){sub 2}(IMes)(Et{sub 2}C=O)]{sup +}[B(C{sub 6}F{sub 5}){sub 4}]{sup -} produces an equilibrium with the dihydride [CpW(CO){sub 2}(IMes)(H){sub 2}]{sup +} (K{sub eq} = 1.1 x 10{sup 3} at 25 {sup o}C). The tungsten ketone complex [CpW(CO){sub 2}(IMes)(Et{sub 2}C=O)]{sup +}[B(C{sub 6}F{sub 5}){sub 4}]{sup -}- serves as a modest catalyst for hydrogenation of Et{sub 2}C=O to Et{sub 2}CH-OH in neat ketone solvent. Decomposition of the catalyst produces [H(IMes)]{sup +}B(C{sub 6}F{sub 5}){sub 4}{sup -}, indicating that these
Donovan, J E; Jessor, R
1983-01-01
Analyses of data from two nationwide surveys of high school students, one carried out in 1974 and the other in 1978, suggest that problem drinking may be seen as yet another step along an underlying dimension of involvement with both licit and illicit drugs. The dimension of involvement with drugs consists of the following levels: nonuse of alcohol or illicit drugs; nonproblem use of alcohol; marijuana use; problem drinking; use of pills (amphetamines, barbiturates, hallucinogenic drugs); and the use of "hard drugs" such as cocaine or heroin. The dimension possesses excellent Guttman-scale properties in both national samples as well as in subsamples differing in gender and ethnic background. The ordering of the levels of involvement was confirmed by the ordering of the alcohol-drug involvement groups based on their mean scores on measures of psychosocial proneness for involvement in problem behavior. The excessive use of a licit drug, i.e., problem drinking, appears to indicate greater involvement in drug use than does the use of an illicit drug, marijuana. This finding points to the importance of distinguishing between use and problem use of drugs in efforts to understand adolescent drug involvement. PMID:6837819
ERIC Educational Resources Information Center
Jewett, John W., Jr.
2008-01-01
Energy is a critical concept in physics problem-solving, but is often a major source of confusion for students if the presentation is not carefully crafted by the instructor or the textbook. A common approach to problems involving deformable or rotating systems that has been discussed in the literature is to employ the work-kinetic energy theorem…
ERIC Educational Resources Information Center
Jewett, John W., Jr.
2008-01-01
Energy is a critical concept in physics problem-solving, but is often a major source of confusion for students if the presentation is not carefully crafted by the instructor or the textbook. A common approach to problems involving deformable or rotating systems that has been discussed in the literature is to employ the work-kinetic energy theorem…
ERIC Educational Resources Information Center
Ronka, Anna; Pulkkinen, Lea
1998-01-01
Examined longitudinally the relationship between earlier risk factors and later problems in young Finnish women's social functioning. Found that low work involvement mediated between risk factors and accumulation of problems in social functioning in young adulthood. Risk factors increased the likelihood of early motherhood, but early motherhood…
ERIC Educational Resources Information Center
Walitzer, Kimberly S.; Dermen, Kurt H.
2004-01-01
This study evaluated the effects of alcohol-focused spouse involvement and behavioral couples therapy (BCT) in group drinking reduction treatment for male problem drinkers. Sixty-four male clients and their female partners were randomly assigned to 1 of 3 conditions: treatment for problem drinkers only (PDO), couples alcohol-focused treatment, or…
Acceleration of multiple solution of a boundary value problem involving a linear algebraic system
NASA Astrophysics Data System (ADS)
Gazizov, Talgat R.; Kuksenko, Sergey P.; Surovtsev, Roman S.
2016-06-01
Multiple solution of a boundary value problem that involves a linear algebraic system is considered. New approach to acceleration of the solution is proposed. The approach uses the structure of the linear system matrix. Particularly, location of entries in the right columns and low rows of the matrix, which undergo variation due to the computing in the range of parameters, is used to apply block LU decomposition. Application of the approach is considered on the example of multiple computing of the capacitance matrix by method of moments used in numerical electromagnetics. Expressions for analytic estimation of the acceleration are presented. Results of the numerical experiments for solution of 100 linear systems with matrix orders of 1000, 2000, 3000 and different relations of variated and constant entries of the matrix show that block LU decomposition can be effective for multiple solution of linear systems. The speed up compared to pointwise LU factorization increases (up to 15) for larger number and order of considered systems with lower number of variated entries.
Laird, Robert D.; Jordan, Kristi Y.; Dodge, Kenneth A.; Pettit, Gregory S.; Bates, John E.
2009-01-01
A longitudinal, prospective design was used to examine the roles of peer rejection in middle childhood and antisocial peer involvement in early adolescence in the development of adolescent externalizing behavior problems. Both early starter and late starter pathways were considered. Classroom sociometric interviews from ages 6 through 9 years, adolescent reports of peers' behavior at age 13 years, and parent, teacher, and adolescent self-reports of externalizing behavior problems from age 5 through 14 years were available for 400 adolescents. Results indicate that experiencing peer rejection in elementary school and greater involvement with antisocial peers in early adolescence are correlated but that these peer relationship experiences may represent two different pathways to adolescent externalizing behavior problems. Peer rejection experiences, but not involvement with antisocial peers, predict later externalizing behavior problems when controlling for stability in externalizing behavior. Externalizing problems were most common when rejection was experienced repeatedly. Early externalizing problems did not appear to moderate the relation between peer rejection and later problem behavior. Discussion highlights multiple pathways connecting externalizing behavior problems from early childhood through adolescence with peer relationship experiences in middle childhood and early adolescence. PMID:11393650
NASA Astrophysics Data System (ADS)
Ramos, Miguel; Tavares, Hugo; Terracini, Susanna
2016-04-01
Let {Ω subset {R}^N} be an open bounded domain and {m in {N}}. Given {k_1,ldots,k_m in {N}}, we consider a wide class of optimal partition problems involving Dirichlet eigenvalues of elliptic operators, of the following form inf{F({λ_{k1}}(ω_1),ldots,λ_{k_m}(ω_m)): (ω_1,ldots, ω_m) in {P}_m(Ω)}, where {λ_{k_i}(ω_i)} denotes the k i -th eigenvalue of {(-Δ,H10(ω_i))} counting multiplicities, and {{P}_m(Ω)} is the set of all open partitions of {Ω}, namely {P}_m(Ω)={(ω_1, ldots, ω_m):ω_i subset Ω open, ωi \\capω_j=emptyset forall i ≠ j }. While the existence of a quasi-open optimal partition {(ω_1,ldots, ω_m)} follows from a general result by Bucur, Buttazzo and Henrot [Adv Math Sci Appl 8(2):571-579, 1998], the aim of this paper is to associate with such minimal partitions and their eigenfunctions some suitable extremality conditions and to exploit them, proving as well the Lipschitz continuity of some eigenfunctions, and the regularity of the partition in the sense that the free boundary {\\cup_{i=1}^m partial ωi \\cap Ω} is, up to a residual set, locally a {C^{1,α}} hypersurface. This last result extends the ones in the paper by Caffarelli and Lin [J Sci Comput 31(1-2):5-18, 2007] to the case of higher eigenvalues.
Kasckow, John; Brown, Charlotte; Morse, Jennifer Q; Karpov, Irina; Bensasi, Salem; Thomas, Stephen B; Ford, Angela; Reynolds, Charles
2010-07-01
This study compared African Americans' and Caucasians' willingness to participate in an indicated intervention to prevent depression with problem-solving therapy. It also examined participants' problem-solving skills. Hypotheses stated that there would be no racial differences in consent rates and that social problem-solving coping skills would be lower among African Americans than Caucasians. Proportions of African Americans and Caucasians who consented were compared, as were Social Problem Solving Inventory scores between the groups. Of 2,788 individuals approached, 82 (4%) of 1,970 Caucasians and 46 (6%) of 818 African Americans signed consent, and the difference was not significant (p=.09). Racial differences were observed in neither Social Problem Solving Inventory scores nor in the relationship between problem-solving skills and depressive symptoms. African Americans with depression demonstrated a willingness to participate in an indicated trial of depression prevention. Furthermore, both groups would appear to benefit from the problem-solving process.
NASA Astrophysics Data System (ADS)
Osher, Stanley J.; Santosa, Fadil
2001-07-01
Many problems in engineering design involve optimizing the geometry to maximize a certain design objective. Geometrical constraints are often imposed. In this paper, we use the level set method devised in (Osher and Sethian, J. Comput. Phys.79, 12 (1988)), the variational level set calculus presented in (Zhao et al., J. Comput. Phys.127, 179 (1996)), and the projected gradient method, as in (Rudin et al., Physica D.60, 259 (1992)), to construct a simple numerical approach for problems of this type. We apply this technique to a model problem involving a vibrating system whose resonant frequency or whose spectral gap is to be optimized subject to constraints on geometry. Our numerical results are quite promising. We expect to use this approach to deal with a wide class of optimal design problems in the future.
A Problem and Its Solution Involving Maxwell's Equations and an Inhomogeneous Medium.
ERIC Educational Resources Information Center
Williamson, W., Jr.
1980-01-01
Maxwell's equation are solved for an inhomogeneous medium which has a coordinate-dependent dielectric function. The problem and its solutions are given in a format which should make it useful as an intermediate or advanced level problem in an electrodynamics course. (Author/SK)
A Problem and Its Solution Involving Maxwell's Equations and an Inhomogeneous Medium.
ERIC Educational Resources Information Center
Williamson, W., Jr.
1980-01-01
Maxwell's equation are solved for an inhomogeneous medium which has a coordinate-dependent dielectric function. The problem and its solutions are given in a format which should make it useful as an intermediate or advanced level problem in an electrodynamics course. (Author/SK)
Basto-Pereira, Miguel; Miranda, Ana; Ribeiro, Sofia; Maia, Ângela
2016-12-01
Several studies have been carried out to investigate the effect of child maltreatment on juvenile justice involvement and future criminal life. However, little is known about the impact of other forms of adversity, beyond abuse and neglect, on juvenile delinquency and criminal persistence. The effect of early adversity on psychosocial problems is underexplored, particularly in juvenile delinquents. This study, using the Childhood Adverse Experiences (ACE) questionnaire, a tool accessing the exposure to different types of abuse, neglect and serious household dysfunction, explored the role of each adverse experience on juvenile justice involvement, persistence in crime and psychosocial problems during young adulthood. A Portuguese sample of 75 young adults with official records of juvenile delinquency in 2010/2011, and 240 young adults from a community sample completed ACE questionnaire and measures of psychosocial adjustment. Seven out of ten adverse experiences were significantly more prevalent in young adults with juvenile justice involvement than in the community sample, after matching the main demographic variables. The strongest predictor of juvenile justice involvement and criminal persistence during early adulthood was sexual abuse. Dimensions of child/adolescent emotional maltreatment and a mental illness in the household predicted a set of psychosocial problems in young adulthood. This study indicates that early adversity is significantly related to juvenile justice involvement, criminal persistence and psychosocial problems. This study also suggests that each experience has a different role in this process. There is an urgent need to screen, prevent and stop serious adversity. Future scientific directions and recommendations for policies are provided.
Kletzel, Morris; Powers, Kim; Hayes, Meghan
2014-08-01
Vitamin C deficiency in developed countries is typically observed in patients with unique clinical conditions such as cystic fibrosis or anorexia nervosa, or in patients on long-term tube feeds. We report here a clinical observation in six pediatric and adolescent patients (median age 17.5 yr, range 9.8-23.5 yr) with chronic GVHD with mucous membrane involvement found to be vitamin C deficient. These patients' baseline serum vitamin C levels ranged from <0.12 to 0.94 mg/dL (normal value 0.20-1.90 mg/dL), with a mean level 0.56 ± 0.36 mg/dL and a median level 0.6 mg/dL. Among these patients, signs and symptoms of mucositis failed to respond to standard chronic GVHD therapy. After receiving treatment with 2000 mg of ascorbic acid by mouth, daily patients displayed increased serum vitamin C levels. Clinically, this correlated with a remarkable improvement in patients' mucositis and ability to eat. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Yen, Cheng-Fang; Lin, I-Mei; Liu, Tai-Ling; Hu, Huei-Fan; Cheng, Chung-Ping
2014-08-01
This study aimed to examine the mediating effects of depression and anxiety on the relationships of bullying victimization and perpetration with pain among adolescents in Taiwan. A total of 4976 students of junior and senior high schools completed the questionnaires. Bullying victimization and perpetration, pain problems, depression, and anxiety were assessed. The mediating effects of depression and anxiety on the relationship between bullying involvement and pain problems and the moderating effects of sex on the medicating roles of depression and anxiety were examined by structural equation model. Both depression and anxiety were significant mediators of the relationship between bullying victimization and pain problems among adolescents. Depression was also a significant mediator of the relationship between bullying perpetration and pain problems among adolescents. Sex had no moderating effect on the mediating role of depression/anxiety on the association between bullying involvement and pain problems. Medical and educational professionals should survey and intervene in depression and anxiety when managing pain problems among adolescents involved in bullying. Copyright © 2014 Elsevier Inc. All rights reserved.
Hoeve, Machteld; Colins, Olivier F; Mulder, Eva A; Loeber, Rolf; Stams, Geert Jan J M; Vermeiren, Robert R J M
2015-01-01
The link between childhood maltreatment and adolescent aggression is well documented; yet, studies examining potential mechanisms that explain this association are limited. In the present study, we tested the association between childhood maltreatment and adolescent aggression in boys in juvenile justice facilities (N = 767) and examined the contribution of mental health problems to this relationship. Data on childhood maltreatment, mental health problems, and aggression were collected by means of self-report measures and structural equation models were used to test mediation models. We found that mental health problems mediated the link between maltreatment and aggression. Results demonstrated different pathways depending on the type of aggression examined. The association between childhood maltreatment and reactive aggression was fully mediated by a variety of mental health problems and for proactive aggression the association was partially mediated by mental health problems. We also found that reactive and proactive aggression partially mediated the association between maltreatment and mental health problems. These findings suggest that a transactional model may best explain the negative effects of childhood trauma on mental health problems and (in particular reactive) aggression. In addition, our findings add to the existing evidence that reactive and proactive aggression have different etiological pathways.
ERIC Educational Resources Information Center
Kauffman, James M.; Hallahan, Daniel P.
2009-01-01
Ethical issues regarding children with disabilities have long involved their treatment after they are born. These issues remain important, but children may be deliberately created with or without characteristics that are usually thought of as disabilities. Preimplantation genetic diagnosis (PGD) and related technologies that involve human…
ERIC Educational Resources Information Center
Kauffman, James M.; Hallahan, Daniel P.
2009-01-01
Ethical issues regarding children with disabilities have long involved their treatment after they are born. These issues remain important, but children may be deliberately created with or without characteristics that are usually thought of as disabilities. Preimplantation genetic diagnosis (PGD) and related technologies that involve human…
ERIC Educational Resources Information Center
Boyce, W. Thomas; Essex, Marilyn J.; Alkon, Abbey; Goldsmith, H. Hill; Kraemer, Helena C.; Kupfer, David J.
2006-01-01
Objective: To study how early father involvement and children's biobehavioral sensitivity to social contexts interactively predict mental health symptoms in middle childhood. Method: Fathers' involvement in infant care and maternal symptoms of depression were prospectively ascertained in a community-based study of child health and development in…
Problems Involved in the Choice and Use of Materials in Airplane Construction
NASA Technical Reports Server (NTRS)
Brenner, Paul
1932-01-01
The present state of the problem of materials in airplane construction is studied on the basis of data giving the principal characteristics of different materials and showing how they affect the form of airplane parts.
Structuring Process Skills and the Solution of Verbal Problems Involving Science Concepts.
ERIC Educational Resources Information Center
Champagne, Audrey B.; Klopfer, Leopold E.
1981-01-01
Investigates the interaction between semantic knowledge and process skills in eighth-grade students' (N=27) performance in solving two types of problems (analogies and set-membership) of inducing structure drawn from physical geology concepts. (DS)
Liu, Hongjie; Yu, Shuli; Cottrell, Lesley; Lunn, Sonja; Deveaux, Lynette; Brathwaite, Nanika V; Marshall, Sharon; Li, Xiaoming; Stanton, Bonita
2007-07-02
Few studies, particularly in developing countries, have explored the relationship between adolescents and parental values with adolescent problem behaviors. The objectives of the study are to (1) describe adolescents' personal values, their problem behaviors, and the relationships thereof according to gender and (2) examine the relationship between parental values, adolescent values, and adolescents' problem behaviors among sixth-grade students and one of their parents. The data used in these analyses were from the baseline assessment of a school-based HIV risk reduction intervention being conducted and evaluated among sixth grade students and one of their parents across 9 elementary schools in The Bahamas. Personal values were measured by the Portrait Values Questionnaire (PVQ). Seven reported problem behaviors were queried from the students, which included physical fight with a friend, drank alcohol, beer, or wine, smoked a cigarette, pushed or carried any drugs, carried a gun, knife, screwdriver or cutlass to use as a weapon, had sex and used marijuana or other illicit drugs over the past 6 months. Multilevel modeling for binary data was performed to estimate the associations between adolescent and parental values and adolescent problem behaviors. Among 785 students, 47% of the students reported at least one problem behavior. More boys (54%) reported having one or more problem behaviors than girls (41%, p < 0.01). Boys compared to girls expressed a higher level of self-enhancement (means score: 36.5 vs. 35.1; p = 0.03), while girls expressed a higher level of self-transcendence (42.3 vs. 40.7; p = 0.03). The results of multilevel modeling indicates that boys with a higher level of self-enhancement and girls with a higher level of openness to change and a lower level of conservation were more likely to report engagement in problem behaviors. Only two parental values (self-transcendence and conservation) were low or modestly correlated with youth' values (openness
ERIC Educational Resources Information Center
Hallarman, Prudence R.; And Others
The need for a "systems" approach to school-based social competency training has been highlighted by a national commission and the U.S. Department of Education. The Pupil Involvement/Problem-Solving with People (PI/PSP) curriculum has adapted numerous, well-researched social compentency training models targeted for elementary classroom use.…
ERIC Educational Resources Information Center
Solomon, Olga; Heritage, John; Yin, Larry; Maynard, Douglas W.; Bauman, Margaret L.
2016-01-01
Conversation and discourse analyses were used to examine medical problem presentation in pediatric care. Healthcare visits involving children with ASD and typically developing children were analyzed. We examined how children's communicative and epistemic capabilities, and their opportunities to be socialized into a competent patient role are…
ERIC Educational Resources Information Center
Solomon, Olga; Heritage, John; Yin, Larry; Maynard, Douglas W.; Bauman, Margaret L.
2016-01-01
Conversation and discourse analyses were used to examine medical problem presentation in pediatric care. Healthcare visits involving children with ASD and typically developing children were analyzed. We examined how children's communicative and epistemic capabilities, and their opportunities to be socialized into a competent patient role are…
ERIC Educational Resources Information Center
Schiffman, Gilbert B.
Developing a program of treatment for dyslexic readers involves four major problems: (1) definition of the reading isability, (2) administrative and educational inertia, (3) organization of the treatment program, and (4) the need for evaluatio and research. There is great disagreement over definitions of reading disabilities, yet an effective…
ERIC Educational Resources Information Center
Kaufmann, Dagmar R.; Wyman, Peter A.; Forbes-Jones, Emma L.; Barry, Jason
2007-01-01
This study examined the relationships between prosocial involvement (PI), antisocial peer affiliations (APA), and the degree of their overlapping or independent prediction of behavior problems in urban adolescents. Two dimensions of behavior were assessed at ages 9-11 and at ages 13-15: disruptive, aggressive conduct and number of delinquent…
ERIC Educational Resources Information Center
Hallarman, Prudence R.; And Others
The need for a "systems" approach to school-based social competency training has been highlighted by a national commission and the U.S. Department of Education. The Pupil Involvement/Problem-Solving with People (PI/PSP) curriculum has adapted numerous, well-researched social compentency training models targeted for elementary classroom use.…
Some free boundary problems involving non-local diffusion and aggregation
Carrillo, José Antonio; Vázquez, Juan Luis
2015-01-01
We report on recent progress in the study of evolution processes involving degenerate parabolic equations which may exhibit free boundaries. The equations we have selected follow two recent trends in diffusion theory: considering anomalous diffusion with long-range effects, which leads to fractional operators or other operators involving kernels with large tails; and the combination of diffusion and aggregation effects, leading to delicate long-term equilibria whose description is still incipient. PMID:26261360
Görzig, Anke
2016-08-01
Possible links of cyberbullying with suicide and psychological problems have recently received considerable attention. Suicide-related behaviors have also been linked with viewing of associated web content. Studies on traditional bullying indicate that the roles of bullying involvement (bullies, victims, and bully-victims) matter in terms of associations with specific suicide-related behaviors and psychological problems. Yet, related research in the area of cyberbullying is lacking. The current study investigates the association of cyberbullying roles with viewing of specific suicide-related web content and psychological problems. Data from N = 19,406 (50 percent girls) 11-16-year-olds (M = 13.54, SD = 1.68) of a representative sample of Internet-using children in Europe were analyzed. Self-reports were obtained for cyberbullying role, viewing of web content related to self-harm, and suicide, as well as the emotional, peer, and conduct problem subscales of the Strengths and Difficulties Questionnaire (SDQ). Multinomial logistic regression analyses revealed that compared with those not involved in cyberbullying, viewing of web content related to suicide was higher for cybervictims and cyberbully-victims, but not for cyberbullies. Viewing of web content related to self-harm was higher for all cyberbullying roles, especially for cyberbully-victims. Rates of emotional problems were higher among cybervictims and cyberbully-victims, rates of peer problems were higher for cybervictims, and rates of conduct problems were higher for all cyberbullying roles. Moreover, the links between cyberbullying role and viewing of suicide-related web content were independent of psychological problems. The results can be useful to more precisely target efforts toward the specific problems of each cyberbullying role. The outcomes on viewing of web content also indicate an opportunity to enhance the presence of health service providers on Internet platforms.
Problems and methods involved in relating land use to ground-water quality
Barringer, Thomas; Dunn, Dennis; Battaglin, William; Vowinkel, Eric
1990-01-01
Efforts to relate shallow ground-water quality to the land use near a well lead to several statistical difficulties. These include potential uncertainty in land-use categorical data due to misclassification, data closure, distributional skewing, and spatial autocorrelation. Methods of addressing these problems are, respectively, the establishment of limits on minimum buffer radius, the estimation of contrasts, rank-based tests of association, and sub-sampling to prevent buffer overlap. Relations between the presence of purgeable organic compounds in ground water and land use are used to illustrate these problems and methods.
Cole-Lewis, Yasmin C; Gipson, Polly Y; Opperman, Kiel J; Arango, Alejandra; King, Cheryl A
2016-08-01
This study examined religious involvement-private religious practices (PRP), organizational religiousness (OR), and religious support (RS)-in relation to depressive symptoms and suicidal ideation (SI) and its protective role, considering youths' school and parent-family connectedness. Youth, ages 12-15 (n = 161), were screened for peer victimization, bullying perpetration, and low social connectedness, and assessed for depressive symptoms, SI, school connectedness, parent-family connectedness, and religious involvement. Results indicated PRP and RS were associated with lower levels of depressive symptoms; PRP and OR were associated with less SI. Controlling for connectedness, PRP remained associated with less SI only. Results suggest the importance of considering religious involvement as a target of youth depression and suicide prevention interventions.
High-Order Integral Equation Methods for Diffraction Problems Involving Screens and Apertures
NASA Astrophysics Data System (ADS)
Lintner, Stephane K.
This thesis presents a novel approach for the numerical solution of problems of diffraction by infinitely thin screens and apertures. The new methodology relies on combination of weighted versions of the classical operators associated with the Dirichlet and Neumann open-surface problems. In the two-dimensional case, a rigorous proof is presented, establishing that the new weighted formulations give rise to second-kind Fredholm integral equations, thus providing a generalization to open surfaces of the classical closed-surface Calderon formulae. High-order quadrature rules are introduced for the new weighted operators, both in the two-dimensional case as well as the scalar three-dimensional case. Used in conjunction with Krylov subspace iterative methods, these rules give rise to efficient and accurate numerical solvers which produce highly accurate solutions in small numbers of iterations, and whose performance is comparable to that arising from efficient high-order integral solvers recently introduced for closed-surface problems. Numerical results are presented for a wide range of frequencies and a variety of geometries in two- and three-dimensional space, including complex resonating structures as well as, for the first time, accurate numerical solutions of classical diffraction problems considered by the 19th-century pioneers: diffraction of high-frequency waves by the infinitely thin disc, the circular aperture, and the two-hole geometry inherent in Young's experiment.
Prefrontal cortex involvement in creative problem solving in middle adolescence and adulthood.
Kleibeuker, Sietske W; Koolschijn, P Cédric M P; Jolles, Dietsje D; Schel, Margot A; De Dreu, Carsten K W; Crone, Eveline A
2013-07-01
Creative cognition, defined as the generation of new yet appropriate ideas and solutions, serves important adaptive purposes. Here, we tested whether and how middle adolescence, characterized by transformations toward life independency and individuality, is a more profitable phase than adulthood for creative cognition. Behavioral and neural differences for creative problem solving in adolescents (15-17 years) and adults (25-30 years) were measured while performing a matchstick problem task (MPT) in the scanner and the creative ability test (CAT), a visuo-spatial divergent thinking task, outside the scanner. Overall performances were comparable, although MPT performance indicated an advantage for adolescents in creative problem solving. In addition, adolescents showed more activation in lateral prefrontal cortex (ventral and dorsal) during creative problem solving compared to adults. These areas correlated with performances on the MPT and the CAT performance. We discuss that extended prefrontal cortex activation in adolescence is important for exploration and aids in creative cognition. Copyright © 2013 Elsevier Ltd. All rights reserved.
Some Problems Involved in the Shared Cataloging Subsystem of the Ohio College Library Center.
ERIC Educational Resources Information Center
Sacco, Margaret T.
This report outlines the development of the Ohio College Library Center (OCLC) and considers some basic problems in OCLC shared cataloging--e.g., the uneven quality of input cataloging and increasing number of duplicate records. Summaries of findings from an OCLC evaluative study and two surveys of shared cataloging are presented. The report…
ERIC Educational Resources Information Center
Egaga, Patrick I.; Aderibigbe, S. Akinwumi
2015-01-01
Sustainability of the environment is one of the major problems facing African people, most especially Nigerians. It is unfortunate that women, by the nature of their daily activities of managing the homes and families are in touch with nature and environment and are at greater risk of health hazards and foetal damage. This paper focuses on the…
1988-02-01
involving conducting surfaces with complex geometries. I. Theory Mohamed F. El-Hewle and Richard 1. Cook Franh !. Seiler Research Laboratory, U.S. Air...can be generalized to a surface of an arbi- mittance are then employed with the new geometry- and trary coordinate function as follows. At a surface
NASA Astrophysics Data System (ADS)
Fatone, Lorella; Recchioni, Maria Cristina; Zirilli, Francesco
2006-05-01
In this paper we propose a highly parallelizable numerical method for time dependent acoustic scattering problems involving realistic smart obstacles hit by incoming waves having wavelengths small compared with the characteristic dimension of the obstacles. A smart obstacle is an obstacle that when hit by an incoming wave tries to pursue a goal circulating on its boundary a pressure current. In particular we consider obstacles whose goal is to be undetectable and we refer to them as furtive obstacles. These scattering problems are modelled as optimal control problems for the wave equation. We validate the method proposed to solve the optimal control problem considered on some test problems where a "smart" simplified version of the NASA space shuttle is hit by incoming waves with small wavelengths compared to its characteristic dimension. That is we consider test problems with ratio between the characteristic dimension of the obstacle and wavelength of the time harmonic component of the incoming wave up to approximately one hundred. The website: http://www.econ.univpm.it/recchioni/w14 contains animations and virtual reality applications showing some numerical experiments relative to the problems studied in this paper.
Approximation methods for inverse problems involving the vibration of beams with tip bodies
NASA Technical Reports Server (NTRS)
Rosen, I. G.
1984-01-01
Two cubic spline based approximation schemes for the estimation of structural parameters associated with the transverse vibration of flexible beams with tip appendages are outlined. The identification problem is formulated as a least squares fit to data subject to the system dynamics which are given by a hybrid system of coupled ordinary and partial differential equations. The first approximation scheme is based upon an abstract semigroup formulation of the state equation while a weak/variational form is the basis for the second. Cubic spline based subspaces together with a Rayleigh-Ritz-Galerkin approach were used to construct sequences of easily solved finite dimensional approximating identification problems. Convergence results are briefly discussed and a numerical example demonstrating the feasibility of the schemes and exhibiting their relative performance for purposes of comparison is provided.
Optimal design for problems involving flow and transport phenomena in saturated subsurface systems
NASA Astrophysics Data System (ADS)
Mayer, Alex S.; Kelley, C. T.; Miller, Cass T.
Estimation problems arise routinely in subsurface hydrology for applications that range from water resources management to water quality protection to subsurface restoration. Interest in optimal design of such systems has increased over the last two decades and this area is considered an important and active area of research. In this work, we review the state of the art, assess important challenges that must be resolved to reach a mature level of understanding, and summarize some promising approaches that might help meet some of the challenges. While much has been accomplished to date, we conclude that more work remains before comprehensive, efficient, and robust solution methods exist to solve the most challenging applications in subsurface science. We suggest that future directions of research include the application of direct search solution methods, and developments in stochastic and multi-objective optimization. We present a set of comprehensive test problems for use in the research community as a means for benchmarking and comparing optimization approaches.
NASA Astrophysics Data System (ADS)
Luo, Shunlong; Sun, Yuan
2017-08-01
Quantifications of coherence are intensively studied in the context of completely decoherent operations (i.e., von Neuamnn measurements, or equivalently, orthonormal bases) in recent years. Here we investigate partial coherence (i.e., coherence in the context of partially decoherent operations such as Lüders measurements). A bona fide measure of partial coherence is introduced. As an application, we address the monotonicity problem of K -coherence (a quantifier for coherence in terms of Wigner-Yanase skew information) [Girolami, Phys. Rev. Lett. 113, 170401 (2014), 10.1103/PhysRevLett.113.170401], which is introduced to realize a measure of coherence as axiomatized by Baumgratz, Cramer, and Plenio [Phys. Rev. Lett. 113, 140401 (2014), 10.1103/PhysRevLett.113.140401]. Since K -coherence fails to meet the necessary requirement of monotonicity under incoherent operations, it is desirable to remedy this monotonicity problem. We show that if we modify the original measure by taking skew information with respect to the spectral decomposition of an observable, rather than the observable itself, as a measure of coherence, then the problem disappears, and the resultant coherence measure satisfies the monotonicity. Some concrete examples are discussed and related open issues are indicated.
Dourson, Michael L; Gadagbui, Bernard; Griffin, Susan; Garabrant, David H; Haws, Laurie C; Kirman, Christopher; Tohyama, Chiharu
2013-07-01
The need to remediate contaminated soils is typically accomplished by applying standard risk assessment methods followed by risk management to select remedial options. These human health risk assessments (HHRAs) have been largely conducted in a formulaic manner that relies heavily on standard deterministic exposure, toxicity assumptions and fixed mathematical formulas. The HHRA approach, with its traditional formulaic practice, does not take advantage of problem formulation in the same manner as is done in ecological risk assessment, and historically, has generally failed to emphasize incorporation of site-specific information. In response to these challenges, the National Academy of Sciences recently made several recommendations regarding the conduct of HHRAs, one of which was to begin all such assessments with problem formulation. These recommendations have since been extended to dose response assessment. In accordance with these recommendations, a group of experts presented and discussed findings that highlighted the importance and impact of including problem formulation when determining the need for remediation of dioxin contamination in soils, focusing in particular on exposure assessment is described. Copyright © 2013 Elsevier Inc. All rights reserved.
Raskin, Maryna; Fosse, Nathan E; Easterbrooks, M Ann
2015-01-01
Research on father involvement has shown positive effects on child development. Because fathers in high social risk samples may be hard to recruit or retain in studies, the literature often has relied on maternal report of father involvement. A major limitation of this approach is that unobserved traits of the reporting mothers may distort the real associations between father involvement and children's development. Using maternal data from a large, longitudinal sample (N = 704) of low-income, young mothers, we evaluated the degree to which a stable depressive trait affected the link between mother-reported measures of father involvement and child problems. Three waves of maternal depression data were used to fit a latent state-trait model of depression, allowing for separate estimates of occasion-specific symptoms and stable depressive trait. A latent regression analysis which did not control for this trait revealed a link between father involvement and child problems similar in magnitude to the links reported in the literature. However, this association disappeared once we accounted for the effect of maternal depressive trait. Results suggest that studies using maternal reports of both father and child behaviors should control for such confounding effects. We elaborate on these findings in the conclusion and offer suggestions for future research on the role of fathers in child development.
A new approach to the solution of boundary value problems involving complex configurations
NASA Technical Reports Server (NTRS)
Rubbert, P. E.; Bussoletti, J. E.; Johnson, F. T.; Sidwell, K. W.; Rowe, W. S.; Samant, S. S.; Sengupta, G.; Weatherill, W. H.; Burkhart, R. H.; Woo, A. C.
1986-01-01
A new approach for solving certain types of boundary value problems about complex configurations is presented. Numerical algorithms from such diverse fields as finite elements, preconditioned Krylov subspace methods, discrete Fourier analysis, and integral equations are combined to take advantage of the memory, speed and architecture of current and emerging supercomputers. Although the approach has application to many branches of computational physics, the present effort is concentrated in areas of Computational Fluid Dynamics (CFD) such as steady nonlinear aerodynamics, time harmonic unsteady aerodynamics, and aeroacoustics. The most significant attribute of the approach is that it can handle truly arbitrary boundary geometries and eliminates the difficult task of generating surface fitted grids.
Saldert, Charlotta; Bauer, Malin
2017-09-25
It is known that Parkinson's disease is often accompanied by a motor speech disorder, which results in impaired communication. However, people with Parkinson's disease may also have impaired word retrieval (anomia) and other communicative problems, which have a negative impact on their ability to participate in conversations with family as well as healthcare staff. The aim of the present study was to explore effects of impaired speech and language on communication and how this is managed by people with Parkinson's disease and their spouses. Using a qualitative method based on Conversation Analysis, in-depth analyses were performed on natural conversational interaction in five dyads including elderly men who were at different stages of Parkinson's disease. The findings showed that the motor speech disorder in combination with word retrieval difficulties and adaptations, such as using communication strategies, may result in atypical utterances that are difficult for communication partners to understand. The coexistence of several communication problems compounds the difficulties faced in conversations and individuals with Parkinson's disease are often dependent on cooperation with their communication partner to make themselves understood.
NASA Astrophysics Data System (ADS)
Maciejewska, Beata; Piasecka, Magdalena
This paper shows the results concerning flow boiling heat transfer in an asymmetrically heated vertical minichannel. The heated element for FC-72 Fluorinert flowing in that minichannel was a thin foil. The foil surface temperature was monitored continuously at 18 points by K-type thermocouples from the outer foil surface. Fluid temperature and pressure in the minichannel inlet and outlet, current supplied to the foil and voltage drop were also monitored. Measurements were carried out at 1 s intervals. The objective was to determine the heat transfer coefficient on the heated foil-fluid contact surface in the minichannel. It was obtained from the Robin boundary condition. The foil temperature was the result of solving the nonstationary two-dimensional inverse boundary problem in the heated foil. Using the FEM combined with Trefftz functions as basis functions solved the problem. The unknown temperature values at nodes were calculated by minimising the adequate functional. The values of local heat transfer coefficients were consistent with the results obtained by the authors in their previous studies when steady-state conditions were analysed. This time, however, these values were analysed as time dependent, which facilitated observation of coefficient changes that were impossible to observe under the steady-state conditions.
Multiple positive solutions for Kirchhoff-type problems in R^3 involving critical Sobolev exponents
NASA Astrophysics Data System (ADS)
Fan, Haining
2016-10-01
In this paper, we study the following nonlinear problem of Kirchhoff type with critical Sobolev exponent -(a+bintlimits_{R^3}|nabla u|^2dx)Δ u+u=λ f(x)u^{q-1}+g(x)u^5,quad xin R^3, uin H^1(R^3), where a, b > 0, 4 < q < 6, and {λ} is a positive parameter. Under certain assumptions on f( x) and g( x) and {λ} is small enough, we obtain a relationship between the number of positive solutions and the topology of the global maximum set of g. The Nehari manifold and Ljusternik-Schnirelmann category are the main tools in our study. Moreover, using the Mountain Pass Theorem, we give an existence result about {λ} large.
Multi-choice stochastic transportation problem involving general form of distributions.
Quddoos, Abdul; Ull Hasan, Md Gulzar; Khalid, Mohammad Masood
2014-01-01
Many authors have presented studies of multi-choice stochastic transportation problem (MCSTP) where availability and demand parameters follow a particular probability distribution (such as exponential, weibull, cauchy or extreme value). In this paper an MCSTP is considered where availability and demand parameters follow general form of distribution and a generalized equivalent deterministic model (GMCSTP) of MCSTP is obtained. It is also shown that all previous models obtained by different authors can be deduced with the help of GMCSTP. MCSTP with pareto, power function or burr-XII distributions are also considered and equivalent deterministic models are obtained. To illustrate the proposed model two numerical examples are presented and solved using LINGO 13.0 software package.
NASA Astrophysics Data System (ADS)
Zhan, Qin; Yuan, Yuan; Fan, Xiangtao; Huang, Jianyong; Xiong, Chunyang; Yuan, Fan
2016-06-01
Digital image correlation (DIC) is essentially implicated in a class of inverse problem. Here, a regularization scheme is developed for the subset-based DIC technique to effectively inhibit potential ill-posedness that likely arises in actual deformation calculations and hence enhance numerical stability, accuracy and precision of correlation measurement. With the aid of a parameterized two-dimensional Butterworth window, a regularized subpixel registration strategy is established, in which the amount of speckle information introduced to correlation calculations may be weighted through equivalent subset size constraint. The optimal regularization parameter associated with each individual sampling point is determined in a self-adaptive way by numerically investigating the curve of 2-norm condition number of coefficient matrix versus the corresponding equivalent subset size, based on which the regularized solution can eventually be obtained. Numerical results deriving from both synthetic speckle images and actual experimental images demonstrate the feasibility and effectiveness of the set of newly-proposed regularized DIC algorithms.
The economic analysis of prevention: an illustration involving children's behavior problems.
Foster, E Michael; Jones, Damon E
2007-12-01
Economic analyses of programs to prevent or treat behavioral health problems among children and youth are an important component of intervention research. This study examines the cost-effectiveness of the Fast Track intervention, a multi-year, multi-component intervention designed to reduce violence in at-risk children. Analytic models estimate intervention cost-effectiveness allowing for sampling variation and considering alternative policy-maker willingness to pay levels. Costs of the intervention were estimated using program budgets. The probability of intervention effectiveness is mapped against willingness to pay using cost-effectiveness acceptability curves (CEAC). Cost-effectiveness is gauged using three outcomes measured in grade 9: diagnosis of conduct disorder; acts of interpersonal violence avoided; index criminal offense avoided. Evaluation of the total sample shows that the intervention was not cost-effective at anticipated levels of policy maker's willingness to pay. For those most at-risk, however, the intervention was likely cost-effective. Outcome measures are based on parent reports and so may be subject to respondent bias. Future costs related to conditions such as conduct disorder are speculative based on previous research. Researchers must consider the population targeted for delivery of intervention services when evaluating cost-effectiveness of their intervention. This study indicates that the intervention was cost-effective only for youth most at-risk for behavioral problems. This result implies that overall cost-effectiveness would be improved by better targeting. The intervention is cost-effective for the highest risk children. From a policy standpoint, this finding is encouraging since such children are likely to generate high costs for taxpayers and society over their lifetimes. Nonetheless, the initial outlay required to finance the program is substantial. Interventionists should consider program costs in designing interventions in
Extending Clinical Equipoise to Phase 1 Trials Involving Patients: Unresolved Problems
Anderson, James A.; Kimmelman, Jonathan
2015-01-01
Notwithstanding requirements for scientific/social value and risk/ benefit proportionality in major research ethics policies, there are no widely accepted standards for these judgments in Phase 1 trials. This paper examines whether the principle of clinical equipoise can be used as a standard for assessing the ratio of risk to direct-benefit presented by drugs administered in one category of Phase 1 study—first-in-human trials involving patients. On the basis of the supporting evidence for, and architecture of, Phase 1 studies, the articles offers two provisional conclusions: (1) the risks of drug administration in such trials cannot generally be justified on therapeutic grounds but by appeal to the social value of the research; and (2) a framework for adjudicating the ratio of risk/ social-value must be developed. PMID:20506695
Factors involved in making post-performance judgments in mathematics problem-solving.
García Fernández, Trinidad; Kroesbergen, Evelyn; Rodríguez Pérez, Celestino; González-Castro, Paloma; González-Pienda, Julio A
2015-01-01
This study examines the impact of executive functions, affective-motivational variables related to mathematics, mathematics achievement and task characteristics on fifth and sixth graders’ calibration accuracy after completing two mathematical problems. A sample of 188 students took part in the study. They were divided into two groups as function of their judgment accuracy after completing the two tasks (accurate= 79, inaccurate= 109). Differences between these groups were examined. The discriminative value of these variables to predict group membership was analyzed, as well as the effect of age, gender, and grade level. The results indicated that accurate students showed better levels of executive functioning, and more positive feelings, beliefs, and motivation related to mathematics. They also spent more time on the tasks. Mathematics achievement, perceived usefulness of mathematics, and time spent on Task 1 significantly predicted group membership, classifying 71.3% of the sample correctly. These results support the relationship between academic achievement and calibration accuracy, suggesting the need to consider a wide range of factors when explaining performance judgments.
[Basic and clinical research of impotence--its present situation and problems involved].
Shirai, M
1990-07-01
From detailed investigation of the vascular structure of the penis, it has been proposed that there exists a valvular structure, consisting of smooth muscle, located at a point immediately before the helicine artery, bifurcated from the deep artery, opens to the cavernous sinuses, an area where autonomic nerves are densely distributed, participating in opening and closing the valve. On the other hand, there is said to be no valvular structure in the vein outflowing from the cavernous sinuses, and blood flows into the dorsal penile vein by penetrating the albuginea obliquely or vertically after running parallel in the region immediately below the albuginea. It is considered that, when the valve of the helicine artery opens, blood flows into the cavernous sinuses, expanding them, and as a result the outflowing vein is compressed between the sinuses and the albuginea, or the albuginea itself, acting like a valve and therefore assuming an important function in maintaining erection by disturbing the reflux of blood flow. It is also presumed that the contracting of ishiocavernous muscle plays a part in developing the rigidity of the penis. It is considered, moreover, that the trabecula of the cavernous body consisting of smooth muscle also plays a part in the promotion and disappearance of erection. It is very important to run functional tests of erection when diagnosing impotence, and today many tests are available for differential diagnosis; including papaverine test, dynamic cavernosometry and cavernosography. As for therapy, treatments involving vasoactive agent infusion, such as papaverine or prostaglandin E1 into the cavernous body, have become common. For cases with venous impotence, ligation of the penile deep vein and crus of the penile cavernous body have come to be attempted. Furthermore, revascularization of penile artery can be performed to treat arterial impotence. For cases in whom these methods are not effective, implantation of various penile prostheses
Mezulis, Amy H; Hyde, Janet Shibley; Clark, Roseanne
2004-12-01
This research investigated whether father involvement in infancy may reduce or exacerbate the well-established adverse effect of maternal depression during a child's infancy on behavior problems in childhood. In a community sample (N = 350), the authors found that fathers' self-reported parenting styles interacted with the amount of time fathers spent caring for their infants to moderate the longitudinal effect of maternal depression during the child's infancy on children's internalizing, but not externalizing, behaviors. Low to medium amounts of high-warmth father involvement and high amounts of medium- or high-control father involvement at this time were associated with lower child internalizing behaviors. Paternal depression during a child's infancy exacerbated the effect of maternal depression, but this moderating effect was limited to depressed fathers spending medium to high amounts of time caring for their infants. Results emphasize the moderating role fathers may play in reducing or exacerbating the adverse long-term effects of maternal depression during a child's infancy on later child behavior problems. ((c) 2004 APA, all rights reserved).
Jelassi, H.; De Lesegno, B. Viaris; Pruvost, L.
2007-09-19
We report on the study of the (ns{sub 1/2}+np{sub 1/2})0{sub g}{sup -}Rb{sub 2} and Cs{sub 2} weakly-bound-level photoassociative spectroscopy in a magneto-optical trap. For the analysis, a Lu-Fano graph is plotted for each set of data. We show that an improved LeRoy-Bernstein formula must to be used. The data is then analysed by a classical procedure using the improved LeRoy-Bernstein formula. The (ns{sub 1/2}+np{sub 1/2})0{sub g}{sup -}Rb{sub 2} and Cs{sub 2} multipolar coefficients c{sub 6} are fitted. They are found to be in good agreement with previous results.
NASA Technical Reports Server (NTRS)
Wang, Xiao Yen; Chang, Sin-Chung; Jorgenson, Philip C. E.
1999-01-01
The space-time conservation element and solution element(CE/SE) method is used to study the sound-shock interaction problem. The order of accuracy of numerical schemes is investigated. The linear model problem.govemed by the 1-D scalar convection equation, sound-shock interaction problem governed by the 1-D Euler equations, and the 1-D shock-tube problem which involves moving shock waves and contact surfaces are solved to investigate the order of accuracy of numerical schemes. It is concluded that the accuracy of the CE/SE numerical scheme with designed 2nd-order accuracy becomes 1st order when a moving shock wave exists. However, the absolute error in the CE/SE solution downstream of the shock wave is on the same order as that obtained using a fourth-order accurate essentially nonoscillatory (ENO) scheme. No special techniques are used for either high-frequency low-amplitude waves or shock waves.
NASA Astrophysics Data System (ADS)
Beker, B.
1992-12-01
Numerical modeling of electromagnetic (EM) interaction is normally performed by using either differential or integral equation methods. Both techniques can be implemented to solve problems in frequency or time domain. The method of moments (MOM) approach to solving integral equations has matured to the point where it can be used to solve complex problems. In the past, MOM has only been applied to scattering and radiation problems involving perfectly conducting or isotropic penetrable, lossy or lossless objects. However, many materials, (e.g., composites that are used on the Navy's surface ships in practical applications) exhibit anisotropic properties. To account for these new effects, several integral equation formulations for scattering and radiation by anisotropic objects have been developed recently. The differential equation approach to EM interaction studies has seen the emergence of the finite-difference time-domain (FD-TD) method as the method of choice in many of today's scattering and radiation applications. This approach has been applied to study transient as well as steady-state scattering from many complex structures, radiation from wire antennas, and coupling into wires through narrow apertures in conducting cavities. It is important to determine whether or not, and how effectively, the FD-TD can be used to solve EM interaction problems of interest to the Navy, such as investigating potential EM interference in shipboard communication systems. Consequently, this report partly addresses this issue by dealing exclusively with FD-TD modeling of time-domain EM scattering and radiation.
Meirovitch, Hagai; Cheluvaraja, Srinath; White, Ronald P.
2009-01-01
The Helmholtz free energy, F and the entropy, S are related thermodynamic quantities with a special importance in structural biology. We describe the difficulties in calculating these quantities and review recent methodological developments. Because protein flexibility is essential for function and ligand binding, we discuss the related problems involved in the definition, simulation, and free energy calculation of microstates (such as the α-helical region of a peptide). While the review is broad, a special emphasize is given to methods for calculating the absolute F (S), where our HSMC(D) method is described in some detail. PMID:19519453
Hanss, Daniel; Mentzoni, Rune A; Griffiths, Mark D; Pallesen, Ståle
2015-06-01
Although there is a general lack of empirical evidence that advertising influences gambling participation, the regulation of gambling advertising is hotly debated among academic researchers, treatment specialists, lobby groups, regulators, and policymakers. This study contributes to the ongoing debate by investigating perceived impacts of gambling advertising in a sample of gamblers drawn from the general population in Norway (n = 6,034). Three dimensions of advertising impacts were identified, representing perceived impacts on (a) gambling-related attitudes, interest, and behavior ("involvement"); (b) knowledge about gambling options and providers ("knowledge"); and (c) the degree to which people are aware of gambling advertising ("awareness"). Overall, impacts were strongest for the knowledge dimension, and, for all 3 dimensions, the impact increased with level of advertising exposure. Those identified as problem gamblers in the sample (n = 57) reported advertising impacts concerning involvement more than recreational gamblers, and this finding was not attributable to differences in advertising exposure. Additionally, younger gamblers reported stronger impacts on involvement and knowledge but were less likely to agree that they were aware of gambling advertising than older gamblers. Male gamblers were more likely than female gamblers to report stronger impacts on both involvement and knowledge. These findings are discussed with regard to existing research on gambling advertising as well as their implications for future research and policy-making. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
ERIC Educational Resources Information Center
Boxer, Paul
2011-01-01
Associating with a negative peer group is related to involvement in problem behavior, yet very little research has considered the role of negative peer group affiliations in the context of "real-world" community-based treatments for problem behavior. This study examined the effects of negative peer involvement on case closure status and treatment…
NASA Astrophysics Data System (ADS)
Mohapatra, S.; Sarangi, M. R.
2017-03-01
The solution of water wave scattering problem involving small deformation on a porous bed in a channel, where the upper surface is bounded above by an infinitely extent rigid horizontal surface, is studied here within the framework of linearized water wave theory. In such a situation, there exists only one mode of waves propagating on the porous surface. A simplified perturbation analysis, involving a small parameter ɛ ( ≪ 1), which measures the smallness of the deformation, is employed to reduce the governing Boundary Value Problem (BVP) to a simpler BVP for the first-order correction of the potential function. The first-order potential function and, hence, the first-order reflection and transmission coefficients are obtained by the method based on Fourier transform technique as well as Green's integral theorem with the introduction of appropriate Green's function. Two special examples of bottom deformation: the exponentially damped deformation and the sinusoidal ripple bed, are considered to validate the results. For the particular example of a patch of sinusoidal ripples, the resonant interaction between the bed and the upper surface of the fluid is attained in the neighborhood of a singularity, when the ripples wavenumbers of the bottom deformation become approximately twice the components of the incident field wavenumber along the positive x-direction. Also, the main advantage of the present study is that the results for the values of reflection and transmission coefficients are found to satisfy the energy-balance relation almost accurately.
Sheridan, Kathryn; Haight, Wendy L.; Cleeland, Leah
2011-01-01
Preventive interventions are urgently needed for children from rural, methamphetamine-involved families, who are at risk for the development of aggressive and other externalizing behavioral problems. This mixed method study explored naturally occurring sources of protection and considers the implications for targeted interventions. Participants were 41 children aged six to 14 years from rural families involved with methamphetamine and the public child welfare system, their primary caregivers, and 19 parents recovering from methamphetamine addiction. When invited during semi-structured interviews to talk about their families, 48% of children spontaneously described socially and emotionally supportive relationships with healthy grandparents. Children’s reports of support from grandparents were associated with lower scores on CBCL Social Problems, [t(37)= 2.23, p<.05 ]; externalizing behaviors, [t(37)= 2.07, p<.05]; and aggressive behaviors, [t(37)= 2.75, p<.01]. When asked to talk about their families, 58% of parents spontaneously described the support their children received from grandparents, and 26% also described the support that they had received from their own grandparents. Children’s and parents’ descriptions of grandparent support suggest how grandparents may protect children from the development of aggressive and other externalizing behavior problems. First, grandparents may prevent obstacles to healthy development by providing their grandchildren with safe shelter and basic child care when parents are incapacitated from substance misuse. Second, they may promote their grandchildren’s positive social-emotional development through supportive relationships. Third, they may promote social competence through enjoyable leisure activities with healthy adults and non-delinquent peers. Understanding naturally occurring sources of protection for children can inform the development of interventions by identifying strengths on which to build, and suggesting
ERIC Educational Resources Information Center
Silver, Edward A.; And Others
This paper reports the latest in a series of studies investigating children's performance in solving division story problems involving remainders. One aspect of the work involved examining the way in which "sense-making" is involved in the interpretation of the numerical solution obtained. Subjects were 195 sixth, seventh, and eighth…
Andreas, Jasmina Burdzovic; O'Farrell, Timothy J
2009-01-01
We investigated longitudinal associations between alcohol-dependent fathers' 12-step treatment involvement and their children's internalizing and externalizing problems (N = 125, M(age) = 9.8 +/- 3.1), testing the hypotheses that fathers' greater treatment involvement would benefit later child behavior and that this effect would be mediated by fathers' posttreatment behaviors. The initial association was established between fathers' treatment involvement and children's externalizing problems only, whereas Structural Equation Modeling (SEM) results supported mediating hypotheses. Fathers' greater treatment involvement predicted children's lower externalizing problems 12 months later, and fathers' posttreatment behaviors mediated this association: Greater treatment involvement predicted greater posttreatment Alcoholics Anonymous attendance, which in turn predicted greater abstinence. Finally, fathers' abstinence was associated with lower externalizing problems in children. Theoretical and practical implications of these findings are discussed.
Andreas, Jasmina Burdzovic; O'Farrell, Timothy J
2008-01-01
We investigated longitudinal associations between alcoholic fathers’ 12-step treatment involvement and their children’s internalizing and externalizing problems (N=125, Mage=9.8±3.1), testing the hypotheses that fathers’ greater treatment involvement would benefit later child behavior, and that this effect would be mediated by fathers’ post-treatment behaviors. The initial association was established between fathers’ treatment involvement and children’s externalizing problems only, while structural equation (SEM) results supported mediating hypotheses. Fathers’ greater treatment involvement predicted children’s lower externalizing problems 12 months later, and fathers’ post-treatment behaviors mediated this association: greater treatment involvement predicted greater post-treatment Alcoholics Anonymous (AA) attendance, which in turn predicted greater abstinence. Finally, fathers’ abstinence was associated with lower externalizing problems in children. Theoretical and practical implications of these findings are discussed. PMID:18715745
Pierce, Allan D; Thiam, Amadou G
2012-03-01
A sequence of dictums for mathematical acoustics is given representing opinions intended to be regarded as authoritative, but not necessarily universally agreed upon. The dictums are presented in the context of the detailed solution for a class of problems involving the forced vibration of a long cylinder protruding half-way into a half-space bounded by a compliant surface (impedance boundary) characterized by a spring constant. One limiting case corresponds to a cylinder vibrating within an infinite rigid baffle, and another limiting case corresponds to a vibrating cylinder on the compliant surface of an incompressible fluid. The second limiting case is identified as analogous to that of a floating half-submerged cylinder whose vibrations cause water waves to propagate over the surface. Attention is focused on vibrations at very low frequencies. Difficulties with insuring a causal solution are pointed out and dictums are given as to how one overcomes such difficulties. Various approximation techniques are described. The derivations involve application of the theory of complex variables and the method of matched asymptotic expansions, and the results include the apparent entrained mass in the near field of the cylinder and the radiation resistance per unit length experienced by the vibrating cylinder.
Positron-HF collisions: Prediction of a weakly bound state
Danby, G.; Tennyson, J.
1988-12-12
Ab initio molecular R-matrix calculations are presented for collisions of low-energy positrons with the hydrogen fluoride molecule as a function of HF internuclear separation. Calculations presented are for ..sigma.. total symmetry with and without polarization effects. These calculations mirror recent electron-HF scattering calculations by Morgan and Burke. Strong evidence is obtained for the presence of a bound state of the e/sup +/HF system. The experimental consequences of this result are discussed.
Study of Exotic Weakly Bound Nuclei Using Magnetic Analyzer Mavr
NASA Astrophysics Data System (ADS)
Maslov, V. A.; Kazacha, V. I.; Kolesov, I. V.; Lukyanov, S. M.; Melnikov, V. N.; Osipov, N. F.; Penionzhkevich, Yu. E.; Skobelev, N. K.; Sobolev, Yu. G.; Voskoboinik, E. I.
2016-06-01
A project of the high-resolution magnetic analyzer MAVR is proposed. The analyzer will comprise new magnetic optical and detecting systems for separation and identification of reaction products in a wide range of masses (5-150) and charges (1-60). The magnetic optical system consists of the MSP-144 magnet and a doublet of quadrupole lenses. This will allow the solid angle of the spectrometer to be increased by an order of magnitude up to 30 msr. The magnetic analyzer will have a high momentum resolution (10-4) and high focal-plane dispersion (1.9 m). It will allow products of nuclear reactions at energies up to 30 MeV/nucleon to be detected with the charge resolution ∼1/60. Implementation of the project is divided into two stages: conversion of the magnetic analyzer proper and construction of the nuclear reaction products identification system. The MULTI detecting system is being developed for the MAVR magnetic analyzer to allow detection of nuclear reaction products and their identification by charge Q, atomic number Z, and mass A with a high absolute accuracy. The identification will be performed by measuring the energy loss (ΔE), time of flight (TOF), and total kinetic energy (TKE) of reaction products. The particle trajectories in the analyzer will also be determined using the drift chamber developed jointly with GANIL. The MAVR analyzer will operate in both primary beams of heavy ions and beams of radioactive nuclei produced by the U400 - U400M acceleration complex. It will also be used for measuring energy spectra of nuclear reaction products and as an energy monochromator.
Temperature programmed desorption of weakly bound adsorbates on Au(111)
NASA Astrophysics Data System (ADS)
Engelhart, Daniel P.; Wagner, Roman J. V.; Meling, Artur; Wodtke, Alec M.; Schäfer, Tim
2016-08-01
We have performed temperature programmed desorption (TPD) experiments to analyze the desorption kinetics of Ar, Kr, Xe, C2H2, SF6, N2, NO and CO on Au(111). We report desorption activation energies (Edes), which are an excellent proxy for the binding energies. The derived binding energies scale with the polarizability of the molecules, consistent with the conclusion that the surface-adsorbate bonds arise due to dispersion forces. The reported results serve as a benchmark for theories of dispersion force interactions of molecules at metal surfaces.
Calculations of some weakly bound diatomic molecular negative ions
Li, Y.; Lin, C.D. )
1999-09-01
We examine the existence of stable bound states of some diatomic molecular ions where the neutral molecule itself is either unbound or barely bound. Two bound states have been found for the HeH[sup [minus
Surface photochemistry and dynamics of weakly bound adsorption systems
NASA Astrophysics Data System (ADS)
Watanabe, Kazuo; Matsumoto, Yoshiyasu
1998-04-01
The photo-induced processes of methane adsorbed on Pt(111) and Pd(111) surfaces have been studied by post-irradiation temperature-programmed desorption and angle-resolved time- of-flight measurements. Methane adsorbs weakly on those metals. Although gaseous methane does not show any appreciable absorption cross sections of 6.4 eV, methane weakly adsorbed on those metals is photodissociated to produce methyl and hydrogen by the irradiation of 6.4-eV photons. The incident angle dependence of cross sections of the photochemistry obtained with linearly polarized light indicates that direct electronic excitation of methane adsorbate plays an important role in the photochemistry of methane. We interpreted that the photochemistry is induced via the electronic transition from the ground state localized at methane to the excited state of the methane- substrate atom complex where the first excited Rydberg-like state of methane significantly mixed with substrate empty states. Photofragments of methane, H and CH3, further react with preadsorbed methyl and hydrogen species, respectively. In particular, methane is desorbed via associative recombination between a `hot' hydrogen and a methyl adsorbate. The average translational energy of the desorbed methane is 0.26 eV and 0.53 eV for Pd(111) and Pt(111), respectively. This difference can be explained by the difference in the surface electronic structure between Pd(111) and Pt(111).
ERIC Educational Resources Information Center
Smith, Erin N.; Grau, Josefina M.; Duran, Petra A.; Castellanos, Patricia
2013-01-01
We examined the relations between maternal depressive symptoms and child internalizing and externalizing problems in a sample of 125 adolescent Latina mothers (primarily Puerto Rican) and their toddlers. We also tested the influence of mother-reported partner child care involvement on child behavior problems and explored mother-reported partner…
ERIC Educational Resources Information Center
Smith, Erin N.; Grau, Josefina M.; Duran, Petra A.; Castellanos, Patricia
2013-01-01
We examined the relations between maternal depressive symptoms and child internalizing and externalizing problems in a sample of 125 adolescent Latina mothers (primarily Puerto Rican) and their toddlers. We also tested the influence of mother-reported partner child care involvement on child behavior problems and explored mother-reported partner…
Na, Ji Ung; Sim, Min Seob; Jo, Ik Joon; Song, Hyoung Gon
2012-06-01
The authors investigated the duration of health problems of people involved with cleanup efforts for the Hebei Spirit oil spill, which occurred in December 2007 in Taean County, South Korea. The study identified risk factors correlated with the continuation of symptoms. Approximately one year after the accident, 442 people who had participated in the cleanup operation were examined. Data regarding demographic information, risk factors, and the continuation and duration of any symptoms were obtained. Eye symptoms (9.7 months), headaches (8.4 months), skin symptoms (8.3 months), and neurovestibular symptoms (6.9 months) had a relatively longer duration than did back pain (1.8 months) or respiratory symptoms (2.1 months). In particular, the remission of headaches had a negative correlation with female gender (HR 0.57, 0.34-0.95, 95% CI), and remission of eye symptoms had a negative correlation with the total hours of daily participation in the cleanup operation (HR 0.24, 0.06-0.95, 95% CI). Copyright © 2012 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Jewel, Joseph W., Jr.; Whitten, James B.
1960-01-01
An investigation has been conducted to determine the problems involved in an emergency method of guiding a gliding vehicle from high altitudes to a high key position (initial position) above a landing field. A jet airplane in a simulated flameout condition, conventional ground-tracking radar, and a scaled wire for guidance programming on the radar plotting board were used in the tests. Starting test altitudes varied from 30,000 feet to 46,500 feet, and starting positions ranged 8.4 to 67 nautical miles from the high key. Specified altitudes of the high key were 12,000, 10,000 or 4,000 feet. Lift-drag ratios of the aircraft of either 17, 16, or 6 were held constant during any given flight; however, for a few flights the lift-drag ratio was varied from 11 to 6. Indicated airspeeds were held constant at either 160 or 250 knots. Results from these tests indicate that a gliding vehicle having a lift-drag ratio of 16 and an indicated approach speed of 160 knots can be guided to within 800 feet vertically and 2,400 feet laterally of a high key position. When the lift-drag ratio of the vehicle is reduced to 6 and the indicated approach speed is raised to 250 knots, the radar controller was able to guide the vehicle to within 2,400 feet vertically and au feet laterally of the high key. It was also found that radar stations which give only azimuth-distance information could control the glide path of a gliding vehicle as well as stations that receive azimuth-distance-altitude information, provided that altitude information is supplied by the pilot.
NASA Technical Reports Server (NTRS)
Tamma, Kumar K.; Namburu, Raju R.
1989-01-01
Numerical simulations are presented for hyperbolic heat-conduction problems that involve non-Fourier effects, using explicit, Lax-Wendroff/Taylor-Galerkin FEM formulations as the principal computational tool. Also employed are smoothing techniques which stabilize the numerical noise and accurately predict the propagating thermal disturbances. The accurate capture of propagating thermal disturbances at characteristic time-step values is achieved; numerical test cases are presented which validate the proposed hyperbolic heat-conduction problem concepts.
NASA Technical Reports Server (NTRS)
Tamma, Kumar K.; Namburu, Raju R.
1989-01-01
Numerical simulations are presented for hyperbolic heat-conduction problems that involve non-Fourier effects, using explicit, Lax-Wendroff/Taylor-Galerkin FEM formulations as the principal computational tool. Also employed are smoothing techniques which stabilize the numerical noise and accurately predict the propagating thermal disturbances. The accurate capture of propagating thermal disturbances at characteristic time-step values is achieved; numerical test cases are presented which validate the proposed hyperbolic heat-conduction problem concepts.
Marken, Richard S; Carey, Timothy A
2015-01-01
A review of the literature on psychotherapy suggests that improvements in effectiveness, efficiency and accessibility have been hampered by a lack of understanding of how psychotherapy works. Central to gaining such understanding is an accurate description of the change process that occurs when someone solves a psychological problem. We describe the Perceptual Control Theory (PCT) model of human functioning, which can be used to understand the nature of psychological problems and how they are solved. PCT suggests that problems can be broadly grouped into two categories: those that can be solved using existing skills and those that require the generation of new skills. In general, psychological problems belong in the second category. PCT describes a fundamental form of learning in which existing structures and systems are reorganized to create new skills, perspective and insights. Psychotherapy based on PCT is aimed at directing reorganization to the source of the problem. Understanding the phenomenon of control is central to understanding how psychotherapy works. Conflict could be considered a general formulation for psychological distress. Therapy will be efficient when the reorganization process is focused at the right level of the client's control hierarchy. Therapy will be effective only when the client's reorganization system-not the therapist-has managed to come up with a solution to the client's problem. What the client says about the nature and reason for their problem is less important than the point of view from which these problems are being discussed. Copyright © 2014 John Wiley & Sons, Ltd.
ERIC Educational Resources Information Center
Cai, Jinfa
1995-01-01
This document is 7th in the Journal for Research in Mathematics Education monograph series. The mathematical performance of (n=250) U.S. 6th-grade students from both private and public schools and (n=425) Chinese 6th-graders from both key and common schools was examined on multiple-choice tasks assessing computation and simple problem solving, and…
Hitchings, Julia E.; Spoth, Richard L.
2010-01-01
Conduct problems are strong positive predictors of substance use and problem substance use among teens, whereas predictive associations of depressed mood with these outcomes are mixed. Conduct problems and depressed mood often co-occur, and such co-occurrence may heighten risk for negative outcomes. Thus, this study examined the interaction of conduct problems and depressed mood at age 11 in relation to substance use and problem use at age 18, and possible mediation through peer substance use at age 16. Analyses of multirater longitudinal data collected from 429 rural youths (222 girls) and their families were conducted using a methodology for testing latent variable interactions. The link between the conduct problems X depressed mood interaction and adolescent substance use was negative and statistically significant. Unexpectedly, positive associations of conduct problems with substance use were stronger at lower levels of depressed mood. A significant negative interaction in relation to peer substance use also was observed, and the estimated indirect effect of the interaction on adolescent use through peer use as a mediator was statistically significant. Findings illustrate the complexity of multiproblem youth. PMID:18455886
ERIC Educational Resources Information Center
Kim, Nam Hee; Park, Jiyeon
2012-01-01
The purpose of this study is to investigate the effects of the Family-Involved Self-Determination Learning Model of Instruction (SDLMI) on academic engagement and goal attainment of middle school students with disabilities who exhibit problem behavior. Intervention was provided to the experimental group (12 students with their families and special…
Nilsson, Anders; Magnusson, Kristoffer; Carlbring, Per; Andersson, Gerhard; Hellner Gumpert, Clara
2016-09-26
Problem gambling is a public health concern affecting ∼2.3% of the Swedish population. Problem gambling also severely affects concerned significant others (CSOs). Several studies have investigated the effect of individual treatments based on cognitive-behavioural therapy (CBT), but less is known of the effect of involving CSOs in treatment. This study aims to compare an intervention based on behavioural couples therapy (BCT), involving a CSO, with an individual CBT treatment to determine their relative efficacy. BCT has shown promising results in working with substance abuse, but this is the first time it is used as an intervention for problem gambling. Both interventions will be internet-delivered, and participants will receive written support and telephone support. A sample of 120 couples will be randomised to either the BCT condition, involving the gambler and the CSO, or the CBT condition, involving the gambler alone. Measures will be conducted weekly and at 3, 6 and 12 months follow-up. The primary outcome measure is gambling behaviour, as measured by Timeline Followback for Gambling. This article describes the outline of the research methods, interventions and outcome measures used to evaluate gambling behaviour, mechanisms of change and relationship satisfaction. This study will be the first study on BCT for problem gambling. This study has been given ethical approval from the regional ethics board of Stockholm, Sweden. It will add to the body of knowledge as to how to treat problem gambling and how to involve CSOs in treatment. The findings of this study will be published in peer-reviewed journals and published at international and national conferences. NCT02543372; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Nilsson, Anders; Andersson, Gerhard; Hellner Gumpert, Clara
2016-01-01
Introduction Problem gambling is a public health concern affecting ∼2.3% of the Swedish population. Problem gambling also severely affects concerned significant others (CSOs). Several studies have investigated the effect of individual treatments based on cognitive–behavioural therapy (CBT), but less is known of the effect of involving CSOs in treatment. This study aims to compare an intervention based on behavioural couples therapy (BCT), involving a CSO, with an individual CBT treatment to determine their relative efficacy. BCT has shown promising results in working with substance abuse, but this is the first time it is used as an intervention for problem gambling. Both interventions will be internet-delivered, and participants will receive written support and telephone support. Methods and analysis A sample of 120 couples will be randomised to either the BCT condition, involving the gambler and the CSO, or the CBT condition, involving the gambler alone. Measures will be conducted weekly and at 3, 6 and 12 months follow-up. The primary outcome measure is gambling behaviour, as measured by Timeline Followback for Gambling. This article describes the outline of the research methods, interventions and outcome measures used to evaluate gambling behaviour, mechanisms of change and relationship satisfaction. This study will be the first study on BCT for problem gambling. Ethics and dissemination This study has been given ethical approval from the regional ethics board of Stockholm, Sweden. It will add to the body of knowledge as to how to treat problem gambling and how to involve CSOs in treatment. The findings of this study will be published in peer-reviewed journals and published at international and national conferences. Trial registration number NCT02543372; Pre-results. PMID:27670519
ERIC Educational Resources Information Center
Mason, W. Alex; Spoth, Richard L.
2011-01-01
Adolescent alcohol involvement is associated with numerous negative outcomes, but also appears to have positive correlates, including subjective well-being. Additional research is needed to understand these paradoxical findings. The current study examines alcohol use, adverse alcohol-related (and other substance-related) consequences, and…
ERIC Educational Resources Information Center
Mason, W. Alex; Spoth, Richard L.
2011-01-01
Adolescent alcohol involvement is associated with numerous negative outcomes, but also appears to have positive correlates, including subjective well-being. Additional research is needed to understand these paradoxical findings. The current study examines alcohol use, adverse alcohol-related (and other substance-related) consequences, and…
NASA Technical Reports Server (NTRS)
Dyall, Kenneth G.
1992-01-01
The effect of omission of two-electron integrals involving basis functions for the small component of the wavefunction on the eigenvalue spectrum in the Dirac-Hartree-Fock problem is studied. From an analysis of the Fock matrix it is shown that omission of these integrals moves the negative-energy states down, not up. Their complete omission does not give rise to intruder states. The appearance of intruder states occurs when only some of the core integrals are omitted, due to the nature of particular contraction schemes used for the core basis functions. Use of radially localized functions rather than atomic functions alleviates the intruder state problem.
NASA Technical Reports Server (NTRS)
Dyall, Kenneth G.
1992-01-01
The effect of omission of two-electron integrals involving basis functions for the small component of the wavefunction on the eigenvalue spectrum in the Dirac-Hartree-Fock problem is studied. From an analysis of the Fock matrix it is shown that omission of these integrals moves the negative-energy states down, not up. Their complete omission does not give rise to intruder states. The appearance of intruder states occurs when only some of the core integrals are omitted, due to the nature of particular contraction schemes used for the core basis functions. Use of radially localized functions rather than atomic functions alleviates the intruder state problem.
Morandi, M; Stanghellini, L; Valeri, A
1985-01-01
The large-scale and continuous cycle production of Hu beta-IFN serves to indicate that with expansion of cell cultures, aspects such as the reliability of the growth media and the possibility of contamination of cultures may become critical and limiting factors for the production itself. Methods of growth media preparation are described, with particular stress on the problems related to bacterial contamination and water quality. Our production method involves the expansion of cellular cultures using roller bottles, and a final step using the microcarrier technique. The necessity of collecting the cultures in only two fermentors increases the possibilities of contamination. Methods employed in order to minimize these problems are discussed.
Solomon, Olga; Heritage, John; Yin, Larry; Marynard, Douglas; Bauman, Margaret
2015-01-01
Conversation and discourse analyses were used to examine medical problem presentation in pediatric care. Healthcare visits involving children with ASD and typically developing children were analyzed. We examined how children’s communicative and epistemic capabilities and their opportunities to be socialized into a competent patient role are interactionally achieved. We found that medical problem presentation is designed to contain a ‘pre-visit’ account of the interactional and epistemic work that children and caregivers carry out at home to identify the child’s health problems; and that the intersubjective accessibility of children’s experiences that becomes disrupted by ASD presents a dilemma to all participants in the visit. The article examines interactional roots of unmet healthcare needs and foregone medical care of people with ASD. PMID:26463739
Nwabuzor Ogbonnaya, Ijeoma; Kohl, Patricia L
2016-02-24
Over the past 10 years, there has been a significant decline in the rate of domestic violence (DV) experienced among caregivers involved with the child protective services (CPS) system. It is unclear whether this shift is related to changes in caregiver characteristics. Furthermore, despite evidence that suggests CPS caseworkers poorly identify DV and fail to link families to DV services, limited research exists on whether the current CPS interventions that are known to improve caseworkers' DV identification will also improve chances for DV service receipt. The present study uses data from the first and second cohorts of the National Survey of Child and Adolescent Well-Being (NSCAW) to compare differences in demographic characteristics and DV experiences between caregivers in NSCAW I (1999-2000; n = 2,758) and NSCAW II (2008-2009; n = 2,207). We also examine the effects of CPS interventions on NSCAW II caregivers' receipt of DV services external to the CPS agency (i.e., external DV services). Caregivers with caseworker reports of active DV in NSCAW I and II were similar in their demographic characteristics and external DV service experiences. However, caregivers in NSCAW II generally reported lower rates of victimization for specific types of violence than NSCAW I caregivers. Finally, caregivers with active DV involved with an agency that used DV assessment tools were 7.03 times more likely to receive external DV services than those in agencies without DV tools (95% confidence interval [CI] = [2.33, 21.22]). Whereas caregivers in agencies that sometimes (odds ratio [OR] = 0.16, 95% CI = [0.03, 0.99]) or always (OR = 0.15, 95% CI = [0.02, 0.98]) had a DV specialist available were less likely to receive external DV services than those in an agency that never/rarely had a DV specialist available. We recommend CPS agencies use specialized assessment tools to identify DV-affected families and link them to services. Additional research is needed to understand what types
Suárez, B; Lope, V; Pérez-Gómez, B; Aragonés, N; Rodríguez-Artalejo, F; Marqués, F; Guzmán, A; Viloria, L J; Carrasco, J M; Martín-Moreno, J M; López-Abente, G; Pollán, M
2005-11-01
The purpose of this study was to evaluate exposure conditions and acute health effects in subjects participating in the Prestige oil spill cleanup activities and the association between these and the nature of the work and use of protection devices in the regions of Asturias and Cantabria (Spain). The sample comprised 400 subjects in each region, selected from a random sampling of all persons involved in cleanup activities, stratified by type of worker and number of working days. Data were obtained via a structured questionnaire and included information on specific tasks, number of working days, use of protective materials, and acute health effects. These effects were classified into two broad groups: injuries and toxic effects. Data analysis was performed using complex survey methods. Significant differences between groups were evaluated using Pearson's chi(2) test. Unconditional logistic regression was used to compute odds ratios and 95% confidence intervals. Bird cleaners accounted for the highest prevalence of injuries (19% presented with lesions). Working more than 20 days in highly polluted areas was associated with increased risk of injury in all workers. Occurrence of toxic effects was higher among seamen, possibly due to higher exposure to fuel oil and its components. Toxic effects were more frequent among those working longer than 20 days in highly polluted areas, performing three or more different cleaning activities, having skin contact with fuel oil on head/neck or upper limbs, and eating while in contact with fuel or perceiving disturbing odors. No severe disorders were identified among individuals who performed these tasks. However, potential health impact should be considered when organizing cleanup activities in similar environmental disasters.
NASA Astrophysics Data System (ADS)
Staszewska, G.
1981-06-01
A new approach to the solution of coupled equations involved in electron-ion and electron-atom scattering problems is proposed. This method is a combination of iteration and variation procedures. The main advantage of this method is that exchange terms can be calculated in a direct and straightforward manner. The method is based on the Lippmann-Schwinger equation and does not require trial functions satisfying appropriate boundary conditions. Using the Volterra formulation one can find the solution on an interval determined by the range of the exchange potential and the long-range potential terms can be taken into account by a projection procedure giving the asymptotic value of the reactance matrix. The method is tested on the case of electron-hydrogen atom scattering in the 1s-2s and 1s-2s-2p approximation. We have adapted the method proposed originally by Rayski to obtain solutions of coupled equations involved in electron-ion and electron-atom scattering. As mentioned in section 1 the construction of the method secures an automatic fulfilment of the boundary conditions. It allows an easy calculation of the exchange potential as well as an estimation of the introduced approximation. It gives also a possibility of detecting any spurious convergence. Moreover, it is important that this formalism can be applied in the case of normalized as well as unnormalized initial integral equations. This fact is of special importance in the case of long-range interactions. When the method is used for unnormalized (Volterra) equations it allows application of a very convenient projection procedure for treating the long-range terms in the direct potential. Electron-hydrogen atom collisions are investigated as a numerical illustration of the method. In the 1s-2s approximation the normalized equations were solved, while in the 1s-2s-2p approximation the solution was obtained with the help of Volterra equations and the long-range terms of the direct potential were taken into account
ERIC Educational Resources Information Center
Silver, Edward A.; And Others
1993-01-01
Middle school students' (n=200) solutions to division-with-remainder story problems and their attempts to make sense of their answers were analyzed for evidence that supported or refuted hypothesized semantic-processing models. The models helped explain students' failure to solve these problems in school settings. (Contains 17 references.)…
ERIC Educational Resources Information Center
Coutts, Michael J.; Sheridan, Susan M.; Kwon, Kyongboon; Semke, Carrie A.
2012-01-01
Behavioral problems in childhood are associated with academic difficulties including in-school suspensions, high school dropout, and low academic grades and achievement scores. Students with disruptive behavior problems demonstrate higher rates of social risk factors than their nondisruptive peers, including school maladjustment, antisocial…
NASA Astrophysics Data System (ADS)
Abreu, Eduardo; Lambert, Wanderson
2012-05-01
Numerical methods are necessary, and are extremely important, in developing an understanding of the dynamics of multiphase flow of fluids in porous media applications to maximize hydrocarbon recovery as well as to simulate contaminant transport of soluble or insoluble species in groundwater contamination problems. This work deals with a problem very common in water-flooding process in petroleum reservoir to motivate the proposed modeling: the flow of two immiscible and incompressible fluid phases. The system of equations which describe this type of flow is a coupled, highly nonlinear system of time-dependent partial differential equations. The equation for the invading fluid (e.g., water phase) is a convection-dominated, degenerate parabolic partial differential equation whose solutions typically exhibit sharp moving fronts (e.g., moving internal layers with strong gradients) and it is very difficult to approximate numerically. We propose a two-stage numerical method to describe the injection problem for a model of two-phase (water-oil) flow in a porous rock, taking into account both gravity and hysteresis effects for solving transport flow problems in porous media. Indeed, we also investigate the Riemann problem for the one-dimensional, purely hyperbolic system, associated to the full differential model problem at hand. Thus, the use of accurate numerical methods in conjunction with one-dimensional semi-analytical Riemann solutions might provide valuable insight into the qualitative solution behavior of the full nonlinear governing flow system.
Iglesias-Sarmiento, Valentín; Deaño, Manuel; Alfonso, Sonia; Conde, Ángeles
2017-02-01
The purpose of this study was to examine the contribution of cognitive functioning to arithmetic problem solving and to explore the cognitive profiles of children with attention deficit and/or hyperactivity disorder (ADHD) and with mathematical learning disabilities (MLD). The sample was made up of a total of 90 students of 4th, 5th, and 6th grade organized in three: ADHD (n=30), MLD (n=30) and typically achieving control (TA; n=30) group. Assessment was conducted in two sessions in which the PASS processes and arithmetic problem solving were evaluated. The ADHD group's performance in planning and attention was worse than that of the control group. Children with MLD obtained poorer results than the control group in planning and simultaneous and successive processing. Executive processes predicted arithmetic problem solving in the ADHD group whereas simultaneous processing was the unique predictor in the MLD sample. Children with ADHD and with MLD showed characteristic cognitive profiles. Groups' problem-solving performance can be predicted from their cognitive functioning. Copyright © 2016 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Fisher, Ramona A.; Collins, Edward C.
Tourette Syndrome is conceptualized as a neurobehavioral disorder, with behavioral aspects that are sometimes difficult for teachers to understand and deal with. The disorder has five layers of complexity: (1) observable multiple motor, vocal, and cognitive tics and sensory involvement; (2) Attention Deficit Hyperactivity Disorder; (3)…
Eaton, Karen M; Hoge, Charles W; Messer, Stephen C; Whitt, Allison A; Cabrera, Oscar A; McGurk, Dennis; Cox, Anthony; Castro, Carl A
2008-11-01
Military spouses must contend with unique issues such as a mobile lifestyle, rules and regulations of military life, and frequent family separations including peacekeeping and combat deployments. These issues may have an adverse effect on the health of military spouses. This study examined the mental health status, rates of care utilization, source of care, as well as barriers and stigma of mental health care utilization among military spouses who were seeking care in military primary care clinics. The data show spouses have similar rates of mental health problems compared to soldiers. Spouses were more likely to seek care for their mental health problems and were less concerned with the stigma of mental health care than were soldiers. Services were most often received from primary care physicians, rather than specialty mental health professionals, which may relate to the lack of availability of mental health services for spouses on military installations.
May, Stephen; Withers, Sarah; Reeve, Sarah; Greasley, Alison
2010-06-01
The aim of this study was to explore the clinical reasoning process used by novice physical therapists in specific patient problems. Nine physical therapists in the UK with limited experience of managing musculoskeletal problems were included. Semi-structured interviews were conducted on how novice physical therapists would assess and manage a patient with a shoulder problem; interviews were transcribed and analyzed using framework analysis. To be included as a final theme at least 50% of participants had to mention that theme. A large number of items (n = 93) were excluded as fewer than 50% of participants referred to each item. Included items related to seven main themes: history (16), physical exam (13), investigations (1), diagnostic reasoning (1), clinical reasoning process (diagnostic pathway) (3), clinical reasoning process (management pathway) (5) and treatment options (1). Items mostly related to information gathering, although there was some use of hypothetico-deductive clinical reasoning there appeared to be limited understanding of the clinical implications of data gathered, and clinical reasoning through use of pattern recognition was minimal. Major weaknesses were apparent in the clinical reasoning skills of these novice therapists compared to previous reports of expert clinical reasoning, indicating areas for development in the education of student and junior physical therapists.
Medveď, Miroslav; Budzák, Šimon; Laurent, Adèle D; Jacquemin, Denis
2015-03-26
Direct (electronic) and indirect (geometrical) modifications of the molecular properties of weakly interacting complexes between the push-pull p-aminobenzoic acid (pABA) molecule and the nonpolar benzene (Bz) have been studied with a large panel of wave function (WF) and density functional theory (DFT) based methods using carefully selected atomic basis sets. For pABA, both the canonical (pABA-c) and zwitterionic (pABA-z) forms have been investigated. Owing to strongly distinct charge distributions, the two forms of pABA enable us to mimic different interaction modes with Bz. In this work, we assessed the performances of dispersion-corrected DFT methods, as well as of long-range corrected exchange-correlation functionals. It follows from the SAPT analysis that both the structure and the interaction energy of the first complex (pABA-c···Bz) is mainly controlled by dispersion interactions whereas, in the second complex (pABA-z···Bz), electrostatic and induction forces play also an important role. Our results suggest that the (non)linear electric properties of push-pull and zwitterionic molecules can be significantly reduced by the presence of a nonpolar compound. We also show that even for a complex with stability strongly determined by dispersion forces, the direct dispersion contributions to its electric properties can be small. Nevertheless, the intersystem distance is influenced by dispersion forces, which, in turn indirectly tune the induced properties. The zwitterionic derivative appears to be more challenging in the context of molecular properties.
Cluster Model for Near-barrier Fusion Induced by Weakly Bound and Halo Nuclei
Beck, C.; Keeley, N.
2008-05-12
The influence on the fusion process of coupling transfer/breakup channels is investigated for the medium weight {sup 6,7}Li+{sup 59}Co systems in the vicinity of the Coulomb barrier. Coupling effects are discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model. Applications to {sup 6}He+{sup 59}Co induced by the borromean halo nucleus {sup 6}He are also proposed.
Near-barrier Fusion Induced by Stable Weakly Bound and Exotic Halo Light Nuclei
Beck, C.; Zafra, A. Sanchez I.; Diaz-Torres, A.; Thompson, I. J.; Keeley, N.
2006-08-14
The effect of breakup is investigated for the medium weight 6Li+59Co system in the vicinity of the Coulomb barrier. The strong coupling of breakup/transfer channels to fusion is discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model which is also applied to 6He+59Co a reaction induced by the borromean halo nucleus 6He.
Ab initio study of weakly bound halogen complexes: RX⋯PH3.
Georg, Herbert C; Fileti, Eudes E; Malaspina, Thaciana
2013-01-01
Ab initio calculations were employed to study the role of ipso carbon hybridization in halogenated compounds RX (R=methyl, phenyl, acetyl, H and X=F, Cl, Br and I) and its interaction with a phosphorus atom, as occurs in the halogen bonded complex type RX⋯PH3. The analysis was performed using ab initio MP2, MP4 and CCSD(T) methods. Systematic energy analysis found that the interaction energies are in the range -4.14 to -11.92 kJ mol(-1) (at MP2 level without ZPE correction). Effects of electronic correlation levels were evaluated at MP4 and CCSD(T) levels and a reduction of up to 27% in interaction energy obtained in MP2 was observed. Analysis of the electrostatic maps confirms that the PhCl⋯PH3 and all MeX⋯PH3 complexes are unstable. NBO analysis suggested that the charge transfer between the moieties is bigger when using iodine than bromine and chlorine. The electrical properties of these complexes (dipole and polarizability) were determined and the most important observed aspect was the systematic increase at the dipole polarizability, given by the interaction polarizability. This increase is in the range of 0.7-6.7 u.a. (about 3-7%).
Dynamics of fragment capture for cluster structures of weakly bound 7Li
NASA Astrophysics Data System (ADS)
Shrivastava, A.; Navin, A.; Diaz-Torres, A.; Nanal, V.; Ramachandran, K.; Rejmund, M.; Bhattacharyya, S.; Chatterjee, A.; Kailas, S.; Lemasson, A.; Palit, R.; Parkar, V. V.; Pillay, R. G.; Rout, P. C.; Sawant, Y.
2013-12-01
Role of cluster structures of 7Li on reaction dynamics have been studied by performing exclusive measurements of prompt-γ rays from residues with scattered particles at energy, E/Vb = 1.6, with 198Pt target. Yields of the residues resulting after capture of t and 4,5,6He, corresponding to different excitation energies of the composite system were estimated. The results were compared with three body classical-dynamical model for breakup fusion, constrained by the measured fusion, α and t capture cross-sections. The cross-section of residues from capture of α and t agreed well with the prediction of the model showing dominance of the two step process - breakup fusion, while those from tightly bound 6He showed massive transfer to be the dominant mechanism.
High-Resolution Magnetic Analyzer MAVR for the Study of Exotic Weakly-Bound Nuclei
NASA Astrophysics Data System (ADS)
Maslov, V. A.; Kazacha, V. I.; Kolesov, I. V.; Lukyanov, S. M.; Melnikov, V. N.; Osipov, N. F.; Penionzhkevich, Yu. E.; Skobelev, N. K.; Sobolev, Yu. G.; Voskoboinik, E. I.
2015-11-01
A project of the high-resolution magnetic analyzer MAVR is proposed. The analyzer will comprise new magnetic optical and detecting systems for separation and identification of reaction products in a wide range of masses (5-150) and charges (1-60). The magnetic optical system consists of the MSP-144 magnet and a doublet of quadrupole lenses. This will allow the solid angle of the spectrometer to be increased by an order of magnitude up to 30 msr. The magnetic analyzer will have a high momentum resolution (10-4) and high focal-plane dispersion (1.9 m). It will allow products of nuclear reactions at energies up to 30 MeV/nucleon to be detected with the charge resolution ~1/60. Implementation of the project is divided into two stages: conversion of the magnetic analyzer proper and construction of the nuclear reaction products identification system. The MULTI detecting system is being developed for the MAVR magnetic analyzer to allow detection of nuclear reaction products and their identification by charge Q, atomic number Z, and mass A with a high absolute accuracy. The identification will be performed by measuring the energy loss (ΔE), time of flight (TOF), and total kinetic energy (TKE) of reaction products. The particle trajectories in the analyzer will also be determined using the drift chamber developed jointly with GANIL. The MAVR analyzer will operate in both primary beams of heavy ions and beams of radioactive nuclei produced by the U400-U400M acceleration complex. It will also be used for measuring energy spectra of nuclear reaction products and as an energy monochromator.
Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions.
Batabyal, Rajib; Morali, Noam; Avraham, Nurit; Sun, Yan; Schmidt, Marcus; Felser, Claudia; Stern, Ady; Yan, Binghai; Beidenkopf, Haim
2016-08-01
Fermi arcs are the surface manifestation of the topological nature of Weyl semimetals, enforced by the bulk-boundary correspondence with the bulk Weyl nodes. The surface of tantalum arsenide, similar to that of other members of the Weyl semimetal class, hosts nontopological bands that obscure the exploration of this correspondence. We use the spatial structure of the Fermi arc wave function, probed by scanning tunneling microscopy, as a spectroscopic tool to distinguish and characterize the surface Fermi arc bands. We find that, as opposed to nontopological states, the Fermi arc wave function is weakly affected by the surface potential: it spreads rather uniformly within the unit cell and penetrates deeper into the bulk. Fermi arcs reside predominantly on tantalum sites, from which the topological bulk bands are derived. Furthermore, we identify a correspondence between the Fermi arc dispersion and the energy and momentum of the bulk Weyl nodes that classify this material as topological. We obtain these results by introducing an analysis based on the role the Bloch wave function has in shaping quantum electronic interference patterns. It thus carries broader applicability to the study of other electronic systems and other physical processes.
Direct experimental observation of weakly-bound character of the attached electron in europium anion
Cheng, Shi-Bo; Castleman, A. W.
2015-01-01
Direct experimental determination of precise electron affinities (EAs) of lanthanides is a longstanding challenge to experimentalists. Considerable debate exists in previous experiment and theory, hindering the complete understanding about the properties of the atomic anions. Herein, we report the first precise photoelectron imaging spectroscopy of europium (Eu), with the aim of eliminating prior contradictions. The measured EA (0.116 ± 0.013 eV) of Eu is in excellent agreement with recently reported theoretical predictions, providing direct spectroscopic evidence that the additional electron is weakly attached. Additionally, a new experimental strategy is proposed that can significantly increase the yield of the lanthanide anions, opening up the best opportunity to complete the periodic table of the atomic anions. The present findings not only serve to resolve previous discrepancy but also will help in improving the depth and accuracy of our understanding about the fundamental properties of the atomic anions. PMID:26198741
Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions
Batabyal, Rajib; Morali, Noam; Avraham, Nurit; Sun, Yan; Schmidt, Marcus; Felser, Claudia; Stern, Ady; Yan, Binghai; Beidenkopf, Haim
2016-01-01
Fermi arcs are the surface manifestation of the topological nature of Weyl semimetals, enforced by the bulk-boundary correspondence with the bulk Weyl nodes. The surface of tantalum arsenide, similar to that of other members of the Weyl semimetal class, hosts nontopological bands that obscure the exploration of this correspondence. We use the spatial structure of the Fermi arc wave function, probed by scanning tunneling microscopy, as a spectroscopic tool to distinguish and characterize the surface Fermi arc bands. We find that, as opposed to nontopological states, the Fermi arc wave function is weakly affected by the surface potential: it spreads rather uniformly within the unit cell and penetrates deeper into the bulk. Fermi arcs reside predominantly on tantalum sites, from which the topological bulk bands are derived. Furthermore, we identify a correspondence between the Fermi arc dispersion and the energy and momentum of the bulk Weyl nodes that classify this material as topological. We obtain these results by introducing an analysis based on the role the Bloch wave function has in shaping quantum electronic interference patterns. It thus carries broader applicability to the study of other electronic systems and other physical processes. PMID:27551687
A new millimeter-wave observation of the weakly bound CO-N2 complex
NASA Astrophysics Data System (ADS)
Surin, L. A.; Potapov, A.; Müller, H. S. P.; Schlemmer, S.
2015-01-01
New millimeter-wave transitions of the CO-N2 van der Waals complex have been observed using the intracavity OROTRON jet spectrometer in the frequency range of 103-159 GHz. For the less abundant form, CO-paraN2, a total of 37 rotational transitions were assigned to three K = 0-0, 0-1, 2-1 subbands connecting the (jCO, jN2) = (1, 1) and (jCO, jN2) = (0, 1) internal rotor states. The upper K = 0 and K = 2 "stacks" of rotational levels were probed for the first time here by millimeter-wave spectroscopy following a recent infrared study by Rezaei et al. (2013). The observation of new subbands fixes with higher precision not only these upper K = 0 and K = 2 but also lower K = 1(f) levels, not linked with other stacks in earlier rotational studies. For the more abundant form, CO-orthoN2, five new P-branch rotational transitions of the K = 0-0 "CO bending" subband are reported, thus extending previous measurements. Nuclear quadrupole hyperfine structure due to the presence of two equivalent 14N nuclei was partly resolved and analyzed to give additional information about the angular orientation of the N2 molecule in the complex.
ClF2: Structure and infrared spectra of a weakly bound triatomic molecule
NASA Astrophysics Data System (ADS)
Galbraith, John Morrison; Vacek, George; Schaefer, Henry F.
1993-05-01
Using sophisticated ab initio methods, the equilibrium structure of the ClF2 radical has been predicted to be bent, confirming previous experimental and theoretical work. The single, double and perturbative triple excitation coupled cluster level of theory along with a triple-ζ plus double polarization basis set gives the geometrical parameters re=1.756 Å and θe=151.8°. At the same level of theory, harmonic vibrational frequencies were predicted to be 536, 243, and 568 cm-1 for the symmetric stretch, bend and asymmetric stretch, respectively. In addition to this high level study of the harmonic vibrational frequencies, theoretical analyses of anharmonic terms have been included in order to help settle the controversy surrounding experimental assignments of the fundamental vibrational frequencies. This research supports Mamantov's experimental assignment of the bending and symmetric stretching fundamental, over the experimental objections of Prochaska. The vibrational frequency splitting due to 37ClF2 was also studied indicating that only the splitting of the bending and asymmetric stretching modes should be readily observable experimentally. Dipole moments and infrared (IR) intensities were also predicted.
NASA Astrophysics Data System (ADS)
Mackenzie, Becca; Dewberry, Chris; Leopold, Ken
2015-06-01
Amine-carboxylic acid interactions are important in many biological systems and have recently received attention for their role in the formation of atmospheric aerosols. Here, we study the molecular and electronic structure of the formic acid - trimethylamine complex, using it as a model for amine-carboxylic acid interactions. The microwave spectrum of the complex has been observed using chirped pulse and conventional cavity-type Fourier transform microwave spectroscopy. The degree of proton transfer has been assessed using the 14N nuclear quadrupole hyperfine structure. Experimental results will be compared to DFT calculations.
Kinetic and Thermochemical Studies of Weakly-Bound HO2 Complexes with Carboxylic acids
NASA Astrophysics Data System (ADS)
Zhao, Z.; Nicovich, J. M.; McKee, M. L.; Wine, P. H.
2008-12-01
Numerous theoretical and experimental studies have suggested that HO2 radicals are able to form strong hydrogen bonds with some closed-shell species, which can potentially influence our understanding of HO2 chemistry in the upper troposphere and lower stratosphere. In this study, a laser flash photolysis-tunable diode laser absorption spectroscopy technique has been employed to study the formation of HO2 complexes with formic and acetic acids. At low temperatures, equilibration kinetics have been observed, allowing adduct formation and dissociation rate coefficients to be obtained and adduct binding enthalpies to be determined. This is the first experimental study of the HO2-carboxylic acid complexes and the binding energies are in good agreement with the most recent theoretical estimates. The potential role of HO2-RC(O)OH adducts in atmospheric chemistry will be discussed.
Applications of Path Integral Langevin Dynamics to Weakly Bound Clusters and Biological Molecules
NASA Astrophysics Data System (ADS)
Ing, Christopher; Hinsen, Conrad; Yang, Jing; Roy, Pierre-Nicholas
2011-06-01
We present the use of path integral molecular dynamics (PIMD) in conjunction with the path integral Langevin equation thermostat for sampling systems that exhibit nuclear quantum effects, notably those at low temperatures or those consisting mainly of hydrogen or helium. To test this approach, the internal energy of doped helium clusters are compared with white-noise Langevin thermostatting and high precision path integral monte carlo (PIMC) simulations. We comment on the structural evolution of these clusters in the absence of rotation and exchange as a function of cluster size. To quantify the importance of both rotation and exchange in our PIMD simulation, we compute band origin shifts for (He)_N-CO_2 as a function of cluster size and compare to previously published experimental and theoretical shifts. A convergence study is presented to confirm the systematic error reduction introduced by increasing path integral beads for our implementation in the Molecular Modelling Toolkit (MMTK) software package. Applications to carbohydrates are explored at biological temperatures by calculating both equilibrium and dynamical properties using the methods presented. M. Ceriotti, M. Parrinello, and D. E. Manolopoulos, J Chem Phys 133, 124104. H. Li, N. Blinov, P.-N. Roy, and R. J. L. Roy, J Chem Phys 130, 144305.
Kaneshiro, Yuko; Furuta, Nami; Makino, Kenichiro; Wada, Futoshi; Hachisuka, Kenji
2011-09-01
We surveyed carbon fiber reinforced plastic orthoses (carbon orthoses) and their associated occupational and medical problems based on a questionnaire sent to 310 companies which were members of the Japan Orthotics and Prosthetics Association. Of all the companies, 232 responded: 77 of the 232 companies dealt with ready-made carbon orthoses, 52 dealt with fabricated custom-made orthoses, and 155 did not dealt with carbon orthoses. Although the total number of custom-made carbon ortheses in Japan was 829/ 5 years, there was a difference by region, and one company fabricated only 12 (per 5 years) custom-made carbon orthoses on average. The advantages of the carbon orthosis were the fact that it was "light weight", "well-fitted", had a "good appearance", and "excellent durability", while the disadvantages were that it was "expensive", "high cost of production", of "black color", and required a "longer time for completion", and "higher fabrication techniques". From the standpoint of industrial medicine, "scattering of fine fragments of carbon fibers", "itching on the skin" and "health hazards" were indicated in companies that manufacture the orthosis. In order to make the carbon orthosis more popular, it is necessary to develop a new carbon material that is easier to fabricate at a lower cost, to improve the fabrication technique, and to resolve the occupational and medical problems.
Patterson, Sue; Weaver, Tim; Agath, Kostas; Albert, Eliot; Rhodes, Timothy; Rutter, Deborah; Crawford, Mike
2009-02-01
Providers of public health care are under pressure to involve service-users in service development. This pressure emanates from legislators and the public who promote user involvement (UI), as a 'means to an end' and/or 'an end in itself'. Case studies in six English commissioning areas explored the process and purpose of UI in drug treatment services. In-depth interviews with 139 respondents who commission, manage, deliver or use services were conducted. We identified 'non-', 'passive-' and 'active participant' users. Active users were commonly motivated by a desire for social justice, a social conscience and personal development. UI was evidently influenced by multiple social organizational and personal factors. Some 'generic' factors have been reported in other settings. However, the illegality of drug use powerfully affects all stakeholders creating a context unique to drug treatment settings. Stigma and power imbalances were pervasive, and strong tensions concerning the goal and purpose of UI were apparent. Within the UK context, we identified five organizational approaches to UI. Based on rationale and objectives of UI, and the scope of influence accorded users, organizations could be characterised as protagonists, pragmatists, sceptics, abstainers or avoiders. We conclude that many tensions apparent in local level UI have roots in UI policy, which is ambiguous about: (1) benefit and rights, and (2) the promotion of healthcare objectives within a UK drug strategy driven by a crime reduction agenda. This duality must be resolved for UI to flourish at local level.
Chen, Ning; Yu, Dejie; Xia, Baizhan; Liu, Jian; Ma, Zhengdong
2017-04-01
This paper presents a homogenization-based interval analysis method for the prediction of coupled structural-acoustic systems involving periodical composites and multi-scale uncertain-but-bounded parameters. In the structural-acoustic system, the macro plate structure is assumed to be composed of a periodically uniform microstructure. The equivalent macro material properties of the microstructure are computed using the homogenization method. By integrating the first-order Taylor expansion interval analysis method with the homogenization-based finite element method, a homogenization-based interval finite element method (HIFEM) is developed to solve a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters. The corresponding formulations of the HIFEM are deduced. A subinterval technique is also introduced into the HIFEM for higher accuracy. Numerical examples of a hexahedral box and an automobile passenger compartment are given to demonstrate the efficiency of the presented method for a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters.
Partitioned Analysis for Multidisciplinary Problems Involving Structures.
1986-04-30
ATTN: R FRANK JOINT STRAT TGT PLANNING STAFF BDM CORP ATTN: JK (ATTN: DNA REP) ATTN: F LEECH LAWRENCE LIVERMORE NATIONAL LABORATORY BDM CORPORATION...KAMAN SCIENCES CORPATTN: LIBRARY/B. KINSLOW AIR FORCE INSTITUTE OF TECHNOLOGY/EN KAMAN SCIENCES CORPORATION ATTN: LIBRARY/AFIT/LDEE ATTN: DASIAC AIR
ERIC Educational Resources Information Center
Greene, Michael B.
Involvement Ratings In Settings (IRIS), a multi-dimensional non-verbal scale of involvement adaptable to a time-sampling method of data collection, was constructed with the aid of the videotapes of second-grade Follow Through classrooms made by CCEP. Scales were defined through observations of involved and alienated behavior, and the IRIS was…
ERIC Educational Resources Information Center
Greene, Michael B.
Involvement Ratings In Settings (IRIS), a multi-dimensional non-verbal scale of involvement adaptable to a time-sampling method of data collection, was constructed with the aid of the videotapes of second-grade Follow Through classrooms made by CCEP. Scales were defined through observations of involved and alienated behavior, and the IRIS was…
Problems with "n"th-Term Problems
ERIC Educational Resources Information Center
Matteson, Shirley M.
2010-01-01
An nth-term problem involves a sequence. Students must determine which expression will allow them to calculate the nth position of the sequence. To solve such problems, students are to find "a rule that determines the number of elements in a step from the step number." These types of problems help students develop concepts of functions, variables,…
ERIC Educational Resources Information Center
Miletich, Yvonne Petrich
A collection of 90 contemporary mathematics story problems are presented for use by elementary teachers. The problems enable students to exercise the steps of problem solving involving operational skills. Instructions given to students list five directions for finding solutions. The answers to all 90 problems are included. This document is part of…
ERIC Educational Resources Information Center
Liontos, Lynn Balster
1992-01-01
Family involvement in schools will work only when perceived as an enlarged concept focusing on all children, including those from at-risk families. Each publication reviewed here is specifically concerned with family involvement strategies concerned with all children or targeted at primarily high risk students. Susan McAllister Swap looks at three…
Measuring Family Problem Solving: The Family Problem Solving Diary.
ERIC Educational Resources Information Center
Kieren, Dianne K.
The development and use of the family problem-solving diary are described. The diary is one of several indicators and measures of family problem-solving behavior. It provides a record of each person's perception of day-to-day family problems (what the problem concerns, what happened, who got involved, what those involved did, how the problem…
Consumer Involvement in Rehabilitation.
ERIC Educational Resources Information Center
Thursz, Daniel
A new approach to rehabilitation of the disabled and disadvantaged is necessary, but the problem of how to involve consumers and how to organize groups for community action is a big one. Moreover, citizen participation cannot be a substitute for basic improvement in the quality of service. Service agencies need to be decentralized and staff…
ERIC Educational Resources Information Center
Kinsella, John J.
1970-01-01
Discussed are the nature of a mathematical problem, problem solving in the traditional and modern mathematics programs, problem solving and psychology, research related to problem solving, and teaching problem solving in algebra and geometry. (CT)
Hansen, Halvor S; Hünenberger, Philippe H
2010-09-14
A new method, ball-and-stick local elevation umbrella sampling (B&S-LEUS), is proposed to enhance the sampling in computer simulations of (bio)molecular systems. It enables the calculation of conformational free-energy differences between states (or alchemical free-energy differences between molecules), even in situations where the definition of these states relies on a conformational subspace involving more than a few degrees of freedom. The B&S-LEUS method consists of the following steps: (A) choice of a reduced conformational subspace; (B) representation of the relevant states by means of spheres ("balls"), each associated with a biasing potential involving a one-dimensional radial memory-based term and a radial confinement term; (C) definition of a set of lines ("sticks") connecting these spheres, each associated with a biasing potential involving a one-dimensional longitudinal memory-based term and a transverse confinement term; (D) unification of the biasing potentials corresponding to the union of all of the spheres and lines (active subspace) into a single biasing potential according to the enveloping distribution sampling (EDS) scheme; (E) build-up of the memory using the local elevation (LE) procedure, leading to a biasing potential enabling a nearly uniform sampling (radially within the spheres, longitudinally within the lines) of the active subspace; (F) generation of a biased ensemble of configurations using this preoptimized biasing potential, following an umbrella sampling (US) approach; and (G) calculation of the relative free energies of the states via reweighting and state assignment. The main characteristics of this approach are: (i) a low internal dimensionality, that is, the memory only involves one-dimensional grids (acceptable memory requirements); (ii) a minimal irrelevant volume, that is, the conformational volume opened to sampling includes a minimal fraction of irrelevant regions in terms of the free energy of the physical system or of
... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...
NASA Astrophysics Data System (ADS)
Allen, Arthur William
The purpose of this study was to examine the cognitive and psychological factors that either enhanced or inhibited Licensed Vocational Nurse (LVN) students' abilities to solve medication-dosage calculation problems. A causal-comparative approach was adopted for use in this study which encompassed aspects of both qualitative and quantitative data collection. A purposive, maximum-variation sample of 20 LVN students was chosen from among a self-selected population of junior college LVN students. The participants' views and feelings concerning their training and clinical experiences in medication administration was explored using a semi-structured interview. In addition, data revealing the students' actual competence at solving sample medication-dosage calculation problems was gathered using a talk-aloud protocol. Results indicated that few participants anticipated difficulty with medication-dosage calculations, yet many participants reported being lost during much of the medication-dosage problem solving instruction in class. While many participants (65%) were able to solve the medication-dosage problems, some (35%) of the participants were unable to correctly solve the problems. Successful students usually spent time analyzing the problem and planning a solution path, and they tended to solve the problem faster than did unsuccessful participants. Successful participants relied on a formula or a proportional statement to solve the problem. They recognized conversion problems as a two-step process and solved the problems in that fashion. Unsuccessful participants often went directly from reading the problem statement to attempts at implementing vague plans. Some unsuccessful participants finished quickly because they just gave up. Others spent considerable time backtracking by rereading the problem and participating in aimless exploration of the problem space. When unsuccessful participants tried to use a formula or a proportion, they were unsure of the formula's or
ERIC Educational Resources Information Center
Trimmer, Ronald G.
This literature review focuses on determining the psychological variables related to problem solving and presents arguments for self-correcting manipulatives as a media for teaching problem solving. Ten traits are considered: attitude, debilitating anxiety, self-concept, orderliness, set, confidence, impulsive/reflective thinking, concentration…
[Population problem, comprehension problem].
Tallon, F
1993-08-01
Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur
Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs
NASA Astrophysics Data System (ADS)
Viel, Alexandra; Simoni, Andrea
2016-04-01
We conduct a theoretical study of magnetically induced Feshbach resonances and near-threshold bound states in isotopic NaK pairs. Our calculations accurately reproduce Feshbach spectroscopy data on Na 40K and explain the origin of the observed multiplets in the p wave [Phys. Rev. A 85, 051602(R) (2012), 10.1103/PhysRevA.85.051602]. We apply the model to predict scattering and bound state threshold properties of the boson-boson Na 39K and Na 41K systems. We find that the Na 39K isotopic pair presents broad magnetic Feshbach resonances and favorable ground-state features for producing nonreactive polar molecules by two-photon association. Broad s -wave resonances are also predicted for Na 41K collisions.
Galano-Frutos, Juan J; Morón, M Carmen; Sancho, Javier
2015-11-21
Binding/unbinding of small ligands, such as ions, to/from proteins influences biochemical processes such as protein folding, enzyme catalysis or protein/ligand recognition. We have investigated the mechanism of chloride/water exchange at a protein surface (that of the apoflavodoxin from Helicobacter pylori) using classical all-atom molecular dynamics simulations. They reveal a variety of chloride exit routes and residence times; the latter is related to specific coordination modes of the anion. The role of solvent molecules in the mechanism of chloride unbinding has been studied in detail. We see no temporary increase in chloride coordination along the release process. Instead, the coordination of new water molecules takes place in most cases after the chloride/protein atom release event has begun. Moreover, the distribution function of water entrance events into the first chloride solvation shell peaks after chloride protein atom dissociation events. All these observations together seem to indicate that water molecules simply fill the vacancies left by the previously coordinating protein residues. We thus propose a step-by-step dissociation pathway in which protein/chloride interactions gradually break down before new water molecules progressively fill the vacant positions left by protein atoms. As observed for other systems, water molecules associated with bound chloride or with protein atoms have longer residence times than those bound to the free anion. The implications of the exchange mechanism proposed for the binding of the FMN (Flavin Mononucleotide) protein cofactor are discussed.
Infrared spectroscopic investigation of two isomers of the weakly bound complex OCS-(CO2)2.
Oliaee, J Norooz; Mivehvar, F; Dehghany, M; Moazzen-Ahmadi, N
2010-12-16
Vibration-rotation spectra of the OCS-(CO(2))(2) van der Waals complex were studied by means of direct infrared absorption spectroscopy. Complexes were generated in a supersonic slit-jet apparatus, and the expansion gas was probed using a rapid-scan tunable diode laser. Infrared bands were observed for two different isomeric forms of the complex. A relatively strong band centered at 2058.799 cm(-1) was assigned to the most stable isomer, which has a barrel-shaped geometry and is already known from microwave spectroscopy. A weaker infrared band centered at 2050.702 cm(-1) was assigned to a new isomeric form, observed here for the first time, which was expected on the basis of ab initio calculations. Infrared bands for seven isotopomers were recorded in an attempt to quantify the structure of the new isomer. Because it has no symmetry elements, nine parameters are needed to fully define the geometry. It was possible to determine six of these which define the relative position of the OCS monomer with respect to the CO(2) dimer fragment in the complex while the remaining three were fixed at their ab initio values. Similarities and differences between the faces of the two isomers of OCS-(CO(2))(2) and the associated dimers are discussed.
ON THE POSSIBLE PRESENCE OF WEAKLY BOUND FULLERENE-H{sub 2} COMPLEXES IN THE INTERSTELLAR MEDIUM
Leidlmair, C.; Bartl, P.; Schoebel, H.; Denifl, S.; Probst, M.; Scheier, P.; Echt, O. E-mail: Paul.Scheier@uibk.ac.at
2011-08-20
The possible contribution of fullerenes and their derivatives to the diffuse interstellar bands (DIBs) has been discussed for some time. Bare fullerenes have been identified in the interstellar medium but they explain few, if any, of the DIBs. In this contribution we show that C{sup +}{sub 60} and C{sup +}{sub 70} will physisorb copious amounts of molecular hydrogen at low temperature. H{sub 2} forms an ordered layer around the fullerene ion; the first coordination shell closes when each carbon ring is decorated with one H{sub 2}. We estimate that fullerenes in dense clouds may very well be complexed with H{sub 2}. The occurrence of H{sub 2}-fullerene complexes in translucent clouds is less likely but cannot be ruled out. They are unlikely to occur in diffuse clouds, which are the major sources of DIBs.
Problem Solving and Intelligence.
ERIC Educational Resources Information Center
Resnick, Lauren B.; Glaser, Robert
This paper argues that a major aspect of intelligence is the ability to solve problems and that careful analysis of problem-solving behavior is a means of specifying many of the psychological processes that make up intelligence. The focus is on the mechanisms involved when, in the absence of complete instruction, a person must "invent" a new…
ERIC Educational Resources Information Center
Wheatley, Judy; Sudman, Rita Schmidt, Ed.
This packet of instructional materials is designed to give social science students in grades 6-9 a first-hand experience in working out solutions to real-life problems involving the management of California's water. Students work in groups on one of three problems presented in the packet: (1) the management of the Sacramento-San Joaquin Delta that…
Inverse problems in mathematical physics
NASA Astrophysics Data System (ADS)
Glasko, V. B.
Procedures for the correct formulation and solution of inverse problems, which usually belong to the class of ill-posed problems, are discussed. Attention is given to the concept of the conditionally correct statement of a problem, the concept of quasi-solution, and the fundamentals of regularization theory. The discussion also covers the uniqueness of solutions to inverse problems in mathematical physics, with consideration given to problems involving layered media, impedance problems, gravimetric problems, and inverse problems of heat conduction. The problem of stability and regularizing operators are also discussed.
... version of this page please turn Javascript on. Balance Problems About Balance Problems Have you ever felt dizzy, lightheaded, or ... dizziness problem during the past year. Why Good Balance is Important Having good balance means being able ...
Energy Problems and Environmental Concern
ERIC Educational Resources Information Center
Train, Russell E.
1973-01-01
Discusses problems encountered in energy extraction and consumption, involving nuclear power plant construction, environmental consequences of energy systems, and energy conservation ethics. Indicates that the increasing concern over environmental quality is not the true cause of present energy problems. (CC)
Energy Problems and Environmental Concern
ERIC Educational Resources Information Center
Train, Russell E.
1973-01-01
Discusses problems encountered in energy extraction and consumption, involving nuclear power plant construction, environmental consequences of energy systems, and energy conservation ethics. Indicates that the increasing concern over environmental quality is not the true cause of present energy problems. (CC)
Fibonacci's Triangle: A Vehicle for Problem Solving.
ERIC Educational Resources Information Center
Ouellette, Hugh
1979-01-01
A method for solving certain types of problems is illustrated by problems related to Fibonacci's triangle. The method involves pattern recognition, generalizing, algebraic manipulation, and mathematical induction. (MP)
Fibonacci's Triangle: A Vehicle for Problem Solving.
ERIC Educational Resources Information Center
Ouellette, Hugh
1979-01-01
A method for solving certain types of problems is illustrated by problems related to Fibonacci's triangle. The method involves pattern recognition, generalizing, algebraic manipulation, and mathematical induction. (MP)
A model for routing problem in quay management problem
NASA Astrophysics Data System (ADS)
Zirour, Mourad; Oughalime, Ahmed; Liong, Choong-Yeun; Ismail, Wan Rosmanira; Omar, Khairuddin
2014-06-01
Quadratic Assignment Problem (QAP), like Vehicle Routing Problem, is one of those optimization problems that interests many researchers in the last decades. The Quay Management Problem is a specific problem which could be presented as a QAP which involves a double assignment of customers and products toward loading positions using lifting trucks. This study focuses on the routing problem while delivering the customers' demands. In this problem, lifting trucks will route around the storage sections to collect the products then deliver to the customers who are assigned to specific loading positions. The objective of minimizing the residence time for each customer is sought. This paper presents the problem and the proposed model.
... Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.
... BMI Calculator myhealthfinder Immunization Schedules Nutrient Shortfall Questionnaire Ear ProblemsEar problems are often caused by an infection. However, other conditions may also cause ear pain or discomfort. Follow this chart for more ...
... premature) labor, when labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with the position of the baby, such as breech, in which the baby is going to come out feet first Birth injuries For some of these problems, the ...
... Read MoreDepression in Children and TeensRead MoreBMI Calculator Mouth ProblemsMouth problems, such as sores, are very common. Follow this chart for more information about mouth problems in adults.Our trusted Symptom Checker is ...
Problem Solving through Paper Folding
ERIC Educational Resources Information Center
Wares, Arsalan
2014-01-01
The purpose of this article is to describe a couple of challenging mathematical problems that involve paper folding. These problem-solving tasks can be used to foster geometric and algebraic thinking among students. The context of paper folding makes some of the abstract mathematical ideas involved relatively concrete. When implemented…
Problem solving using soft systems methodology.
Land, L
This article outlines a method of problem solving which considers holistic solutions to complex problems. Soft systems methodology allows people involved in the problem situation to have control over the decision-making process.
The Problems of Problem Solving
ERIC Educational Resources Information Center
Watson, Charles E.
1976-01-01
Discusses some common pitfalls in problem-solving and outlines three basic approaches to successfully identifying problems and their causes. (Available from Business Horizons, School of Business, Indiana University, Bloomington, Indiana 47401; $2.50, single copy) (Author/JG)
NASA Technical Reports Server (NTRS)
Lesso, W. G.; Kenyon, E.
1972-01-01
Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.
... Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & ... Facts & Information What are Joint Problems? Your musculoskeletal system is constructed of bones, muscles, and joints. The ...
ERIC Educational Resources Information Center
Skovhus, Randi Boelskifte; Thomsen, Rie
2017-01-01
This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…
... and the respiratory system . The ability to understand language and produce speech is coordinated by the brain. So a person with brain damage from an accident, stroke, or birth defect may have speech and language problems. Some people with speech problems, particularly articulation ...
ERIC Educational Resources Information Center
Foster, Colin
2012-01-01
This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember…
ERIC Educational Resources Information Center
Skovhus, Randi Boelskifte; Thomsen, Rie
2017-01-01
This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…
ERIC Educational Resources Information Center
Fetrow, Jessica
2009-01-01
This study focused on how to help students translate word problems so that they understand how to solve them, and so they are successful with word problems. I have created three research questions to focus on during this research project. First, how will direct instruction of word meaning help clarify the operation needed, affect the achievement…
ERIC Educational Resources Information Center
Foster, Colin
2012-01-01
This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember…
... our e-newsletter! Aging & Health A to Z Balance Problems Basic Facts & Information What are Balance Problems? Having good balance means being able to ... Only then can you “keep your balance.” Why Balance is Important Your feelings of dizziness may last ...
ERIC Educational Resources Information Center
Brown, Marion, Comp.; And Others
This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…
ERIC Educational Resources Information Center
Brown, Marion, Comp.; And Others
This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…
ERIC Educational Resources Information Center
De Bono, Edward
A group of children were presented with several tasks, including the invention of a sleep machine and a machine to weigh elephants. The tasks were chosen to involve the children in coping with problems of a distinct character. A study of the children's drawings and interpretations shows that children's thinking ability is not very different from…
Circumference and Problem Solving.
ERIC Educational Resources Information Center
Blackburn, Katie; White, David
The concept of pi is one of great importance to all developed civilization and one that can be explored and mastered by elementary students through an inductive and problem-solving approach. Such an approach is outlined and discussed. The approach involves the following biblical quotation: "And he made a moltin sea ten cubits from one brim to…
Chemical Reaction Problem Solving.
ERIC Educational Resources Information Center
Veal, William
1999-01-01
Discusses the role of chemical-equation problem solving in helping students predict reaction products. Methods for helping students learn this process must be taught to students and future teachers by using pedagogical skills within the content of chemistry. Emphasizes that solving chemical reactions should involve creative cognition where…
Problems on Divisibility of Binomial Coefficients
ERIC Educational Resources Information Center
Osler, Thomas J.; Smoak, James
2004-01-01
Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…
Problems on Divisibility of Binomial Coefficients
ERIC Educational Resources Information Center
Osler, Thomas J.; Smoak, James
2004-01-01
Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…
Predicting the Problem Behavior in Adolescents
ERIC Educational Resources Information Center
Karaman, Neslihan G.
2013-01-01
Problem statement: Problem behavior theory describes both protective factors and risk factors to explain adolescent problem behaviors, such as delinquency, alcohol use, and reckless driving. The theory holds that problem behaviors involving risky behavior are used by adolescents as a means to gain peer acceptance and respect. Problem behaviors…
... do to help diagnose your prostate problem. Physical Exam A physical exam may help diagnose the cause ... sleep avoid or drink fewer liquids that have caffeine or alcohol in them avoid medicines that may ...
... which nothing can be seen) Vision loss and blindness are the most severe vision problems. Considerations Regular ... that look faded. The most common cause of blindness in people over age 60. Eye infection, inflammation, ...
... for a healthy life Mental health for men Sexual health for men Male infertility Prostate health Sexual problems ... updates. Enter email address Submit Home > Men's Health > Sexual health for men Men's Health This information in Spanish ( ...
... thinking, but it becomes disorganized as they're speaking. So, someone who clutters may speak in bursts ... refuse to wait patiently for them to finish speaking. If you have a speech problem, it's fine ...
... for you? Do you make spelling and other errors when you write? Are you having trouble with ... the truth is that learning problems are pretty common. And if your learning specialist or psychologist has ...
... treated differently. Common thyroid disorders and problems include: Hypothyroidism Hypothyroidism is a disorder in which your thyroid doesn’ ... normal after you get better. If you have hypothyroidism, however, the levels of T4 in your blood ...
... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.
... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... PDF 474KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...
Problem-Framing: A perspective on environmental problem-solving
NASA Astrophysics Data System (ADS)
Bardwell, Lisa V.
1991-09-01
The specter of environmental calamity calls for the best efforts of an involved public. Ironically, the way people understand the issues all too often serves to discourage and frustrate rather than motivate them to action. This article draws from problem-solving perspectives offered by cognitive psychology and conflict management to examine a framework for thinking about environmental problems that promises to help rather than hinder efforts to address them. Problem-framing emphasizes focusing on the problem definition. Since how one defines a problem determines one's understanding of and approach to that problem, being able to redefine or reframe a problem and to explore the “problem space” can help broaden the range of alternatives and solutions examined. Problem-framing incorporates a cognitive perspective on how people respond to information. It explains why an emphasis on problem definition is not part of people's typical approach to problems. It recognizes the importance of structure and of having ways to organize that information on one's problem-solving effort. Finally, problem-framing draws on both cognitive psychology and conflict management for strategies to manage information and to create a problem-solving environment that not only encourages participation but can yield better approaches to our environmental problems.
... wine stain, because of its resemblance to a dark red wine. If this birthmark involves the eye, ... examined by an ophthalmologist shortly after birth. Small dark moles, called nevi, on the eyelids or on ...
... own) body. Physical therapy can include Kegel exercises, biofeedback therapy, and pelvic floor muscle rehabilitation. Kegel exercises ... the pelvic floor to increase strength and tone. Biofeedback therapy involves the placement of biofeedback sensors that ...
Are accidents scheduled. [safety management problems
NASA Technical Reports Server (NTRS)
Childs, C.
1976-01-01
Two major sets of safety problems associated with project scheduling are examined. The first set involves problems resulting from the improper scheduling of the safety tasks. The second involves problems which result from inadequate attention to scheduling of those project tasks which lead to tests and operations and includes condensed schedules, modified schedules, schedule workarounds, eliminated portions of the schedules and strung out schedules.
Student Problem-Solving Behaviors
NASA Astrophysics Data System (ADS)
Harper, Kathleen A.
2006-04-01
Kathy Harper is director of undergraduate curriculum development in the physics department at The Ohio State University. She has been involved in local and national workshops for in-service teachers and conducts research in student problem solving.
Eldercare at Home: Memory Problems
... do by themselves." These activities, especially those involving music, can be especially therapeutic. Encourage regular routines. Important ... problem was due to a physical illness or depression, treatment is likely to improve memory. There are ...
ERIC Educational Resources Information Center
Connors, G. Patrick
Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…
ERIC Educational Resources Information Center
Murphy, Pat, Ed.
1993-01-01
"Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty);…
ERIC Educational Resources Information Center
Willcutt, Bob
1974-01-01
Multibase arithmetic blocks are used to investigate the minimum number of blocks of each size to make a square of a given size in a given base. Generalizations are made to any size and any base through pattern recognition. The problem is extended to rectangles, cubes, and rectangular solids. (LS)
ERIC Educational Resources Information Center
Connors, G. Patrick
Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…
Numerical methods for problems involving the Drazin inverse
NASA Technical Reports Server (NTRS)
Meyer, C. D., Jr.
1979-01-01
The objective was to try to develop a useful numerical algorithm for the Drazin inverse and to analyze the numerical aspects of the applications of the Drazin inverse relating to the study of homogeneous Markov chains and systems of linear differential equations with singular coefficient matrices. It is felt that all objectives were accomplished with a measurable degree of success.
The Evaluation of Programs Involving TMR Children: Methodological Problems.
ERIC Educational Resources Information Center
Byrne, Barbara M.
1983-01-01
No significant differences in language skills, social maturity, or self-concept were found for 36 trainable mentally retarded (TMR) elementary students placed in a semi-integrated school environment and 36 TMR Ss in a nonintegrated setting. Concerns regarding assessment of TMR children were noted. (CL)
PROBLEMS INVOLVED IN COOPERATION BETWEEN UNIVERSITIES AND GOVERNMENT AGENCIES.
ERIC Educational Resources Information Center
SHIRLEY, JOHN W.
THE UNRESOLVED PURPOSE OF EDUCATION IN A DEMOCRATIC SOCIETY--WHETHER ACADEMIC OR PRAGMATIC GOALS SHOULD PREVAIL--IS IDENTIFIED AS THE BASIC CAUSE OF THE CONFLICT BETWEEN THE FEDERAL GOVERNMENT AND INSTITUTIONS OF HIGHER EDUCATION. SINCE WORLD WAR II, FEDERAL SUPPORT HAS BEEN INCREASINGLY DIRECTED TOWARD ACTION PROGRAMS, INCLUDING SPECIAL…
Quality Circles: Involvement, Problem-Solving, and Recognition.
ERIC Educational Resources Information Center
Moretz, H. Lynn
1983-01-01
The media production department of Central Piedmont Community College (CPCC) began quality circle meetings in January 1981 after studying the process of quality circles and obtaining the understanding and support of the college administration. A quality circle is a small group of people doing similar work who voluntarily meet on a regular basis to…
Problem Solving, Scaffolding and Learning
ERIC Educational Resources Information Center
Lin, Shih-Yin
2012-01-01
Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…
Problem Solving, Scaffolding and Learning
ERIC Educational Resources Information Center
Lin, Shih-Yin
2012-01-01
Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…
Individualized Math Problems in Logarithms. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
THis is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. This volume includes problems involving logarithms, exponents, and…
Individualized Math Problems in Whole Numbers. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. Problems in this set require computations involving whole numbers.…
Individualized Math Problems in Ratio and Proportion. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. This volume contains problems involving ratio and proportion. Some…
Individualized Math Problems in Fractions. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. This package contains problems involving computation with common…
Individualized Math Problems in Whole Numbers. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. Problems in this set require computations involving whole numbers.…
Individualized Math Problems in Fractions. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. This package contains problems involving computation with common…
Individualized Math Problems in Ratio and Proportion. Oregon Vo-Tech Mathematics Problem Sets.
ERIC Educational Resources Information Center
Cosler, Norma, Ed.
This is one of eighteen sets of individualized mathematics problems developed by the Oregon Vo-Tech Math Project. Each of these problem packages is organized around a mathematical topic and contains problems related to diverse vocations. Solutions are provided for all problems. This volume contains problems involving ratio and proportion. Some…
Enhancing chemistry problem-solving achievement using problem categorization
NASA Astrophysics Data System (ADS)
Bunce, Diane M.; Gabel, Dorothy L.; Samuel, John V.
The enhancement of chemistry students' skill in problem solving through problem categorization is the focus of this study. Twenty-four students in a freshman chemistry course for health professionals are taught how to solve problems using the explicit method of problem solving (EMPS) (Bunce & Heikkinen, 1986). The EMPS is an organized approach to problem analysis which includes encoding the information given in a problem (Given, Asked For), relating this to what is already in long-term memory (Recall), and planning a solution (Overall Plan) before a mathematical solution is attempted. In addition to the EMPS training, treatment students receive three 40-minute sessions following achievement tests in which they are taught how to categorize problems. Control students use this time to review the EMPS solutions of test questions. Although problem categorization is involved in one section of the EMPS (Recall), treatment students who received specific training in problem categorization demonstrate significantly higher achievement on combination problems (those problems requiring the use of more than one chemical topic for their solution) at (p = 0.01) than their counterparts. Significantly higher achievement for treatment students is also measured on an unannounced test (p = 0.02). Analysis of interview transcripts of both treatment and control students illustrates a Rolodex approach to problem solving employed by all students in this study. The Rolodex approach involves organizing equations used to solve problems on mental index cards and flipping through them, matching units given when a new problem is to be solved. A second phenomenon observed during student interviews is the absence of a link in the conceptual understanding of the chemical concepts involved in a problem and the problem-solving skills employed to correctly solve problems. This study shows that explicit training in categorization skills and the EMPS can lead to higher achievement in complex problem
ERIC Educational Resources Information Center
Fisher, Mark A.
1994-01-01
The creative solutions found by four colleges and universities to specific student recruitment dilemmas are described. Two dilemmas involved clarification of the campus' geographic location, one addressed recruitment of minority group engineering students, and the fourth concerned recruitment of exceptionally gifted 13- to 16-year-old girls to an…
Quantitative Relationships Involving Additive Differences: Numerical Resilience
ERIC Educational Resources Information Center
Ramful, Ajay; Ho, Siew Yin
2014-01-01
This case study describes the ways in which problems involving additive differences with unknown starting quantities, constrain the problem solver in articulating the inherent quantitative relationship. It gives empirical evidence to show how numerical reasoning takes over as a Grade 6 student instantiates the quantitative relation by resorting to…
Research on Computers and Problem Solving.
ERIC Educational Resources Information Center
Burton, John K.; And Others
1988-01-01
Eight articles review and report on research involving computers and problem solving skills. Topics discussed include research design; problem solving skills and programing languages, including BASIC and LOGO; computer anxiety; diagnostic programs for arithmetic problems; and relationships between ability and problem solving scores and between…
Word Problems: A "Meme" for Our Times.
ERIC Educational Resources Information Center
Leamnson, Robert N.
1996-01-01
Discusses a novel approach to word problems that involves linear relationships between variables. Argues that working stepwise through intermediates is the way our minds actually work and therefore this should be used in solving word problems. (JRH)
The Problem of Managing a Strategic Reserve.
ERIC Educational Resources Information Center
Cole, David; And Others
1986-01-01
The problem of managing the reserve of cobalt is presented, followed by a method for bringing the stockpiled amount from any level to a desired goal. Solving a stochastic programming problem is involved. The procedure is discussed in detail. (MNS)
The Problem of Managing a Strategic Reserve.
ERIC Educational Resources Information Center
Cole, David; And Others
1986-01-01
The problem of managing the reserve of cobalt is presented, followed by a method for bringing the stockpiled amount from any level to a desired goal. Solving a stochastic programming problem is involved. The procedure is discussed in detail. (MNS)
Word Problems: A "Meme" for Our Times.
ERIC Educational Resources Information Center
Leamnson, Robert N.
1996-01-01
Discusses a novel approach to word problems that involves linear relationships between variables. Argues that working stepwise through intermediates is the way our minds actually work and therefore this should be used in solving word problems. (JRH)
NASA Astrophysics Data System (ADS)
Rubin, Sergey G.
2016-02-01
The way to solve the hierarchy problem based on multidimensional gravity is discussed. Various metrics of deformed extra space are produced at the Planck scale. It is shown that the Higgs vacuum value depends on a metric of extra space and hence their different numerical values are realized in various universes. An interval of the Higgs vacuum values is proved include zero value. Our universe belongs to a set of universes the vacuum values of which are close to zero
NASA Technical Reports Server (NTRS)
Kussner, H G
1937-01-01
The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.
Attitudes Underlying the Politics of Parent Involvement.
ERIC Educational Resources Information Center
Ostrander, Kenneth H.; Ostrom, Katherine
1990-01-01
Factor analysis of 38 interviews with classroom teachers regarding working collaboratively with parents revealed that some teachers have apprehensions about involving parents when potential problems are perceived and the teachers believe they do not have sufficient time to involve parents. (MLF)
32 CFR 651.36 - Public involvement.
Code of Federal Regulations, 2011 CFR
2011-07-01
... National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.36 Public involvement. (a) The... collaborative issue identification and problem solving. Such involvement demonstrates that the Army is committed...
1987-06-01
Vibration of an Elastic Bar We are interested in studying the small, longitudinal vibra- tions of a longitudinally loaded, elastically supported, elastic...u 2 + + 2u O(( m,Q Uk .(J- MO In the study of eigenvalue problems, central use will be made of Rellich’s theorem (cf. Agmon [19651), which states...H , where a > 0. Sufficient conditions for (4.2) - (4.4) to hold were given in Section 3; cf. (3.15) -(3.17). For the study of (4.1) it is useful to
Gubernatorial Involvement in Education.
ERIC Educational Resources Information Center
Hines, Edward R.
This research on 12 States' gubernatorial involvement in State educational policy formation investigates four functional stages of that involvement--issue definition, proposal formulation, support mobilization, and decision enactment. Drawing on the Educational Governance Project information and interviews, a gubernatorial involvement index was…
ERIC Educational Resources Information Center
Quezada, Reyes L.; Diaz, Delia M.; Sanchez, Maria
2003-01-01
Describes barriers to Latino parent involvement in educational activities, factors to consider when involving Latino parents, and two examples of Latino involvement programs in California: Family Literacy Workshop at James Monroe Elementary School, Madera Unified School District, and Parents Take P.A.R.T. (Parent Assisted Reading Training) at…
ERIC Educational Resources Information Center
Montgomery, Joel R.
2008-01-01
This working paper explores reasons to encourage parents of English language learners (ELLs) to be involved in the learning process at the middle school level. Barriers to parental involvement of language minority students will be identified and successful, research-based strategies to increase parental involvement will be introduced. Five…
Involving Faculty in Planning.
ERIC Educational Resources Information Center
Andrew, Lloyd D.
1979-01-01
Firm planning objectives, clearly stated relationships to overall institutional objectives, faculty involvement, and active leadership are advocated for successful academic planning. Faculty involvement is dependent on the strength of the technical, marketing, and budgeting staffs, and involvement in the planning process may kindle faculty…
Renal involvement in antiphospholipid syndrome.
Pons-Estel, Guillermo J; Cervera, Ricard
2014-02-01
Renal involvement can be a serious problem for patients with antiphospholipid syndrome (APS). However, this complication has been poorly recognized and studied. It can be present in patients who have either primary or systemic lupus erythematosus-associated APS. Clinical and laboratory features of renal involvement in APS include hypertension, hematuria, acute renal failure, and progressive chronic renal insufficiency with mild levels of proteinuria that can progress to nephrotic-range proteinuria. The main lesions are renal artery stenosis, venous renal thrombosis, and glomerular lesions (APS nephropathy) that may be acute (thrombotic microangiopathy) and/or chronic (arteriosclerosis, arterial fibrous intimal hyperplasia, tubular thyroidization, arteriolar occlusions, and focal cortical atrophy). APS can also cause end-stage renal disease and allograft vascular thrombosis. This article reviews the range of renal abnormalities associated with APS, and their diagnosis and treatment options.
Reasoning by Analogy in Solving Comparison Problems.
ERIC Educational Resources Information Center
English, Lyn D.
1998-01-01
Investigates 10-year-old children's abilities to reason by analogy in solving addition and subtraction comparison problems involving unknown compare sets and unknown reference sets. Children responded in a consistent manner to the tasks involving the basic addition problems, indicating substantial relational knowledge of these but responded in an…
ERIC Educational Resources Information Center
1996
These three papers were presented at a symposium on high-involvement work teams moderated by Michael Leimbach at the 1996 conference of the Academy of Human Resource Development. "Beyond Training to the New Learning Environment: Workers on the High-Involvement Frontline" (Joseph Anthony Ilacqua, Carol Ann Zulauf) shows the link between…
ERIC Educational Resources Information Center
1996
These three papers were presented at a symposium on high-involvement work teams moderated by Michael Leimbach at the 1996 conference of the Academy of Human Resource Development. "Beyond Training to the New Learning Environment: Workers on the High-Involvement Frontline" (Joseph Anthony Ilacqua, Carol Ann Zulauf) shows the link between…
ERIC Educational Resources Information Center
Garate, Dama; And Others
Four community liaisons for public school programs for limited- English-proficient (LEP) populations discuss briefly aspects of parent involvement. Dama Garate describes the populations served by the Trinity-Arlington Project in the Arlington (Virginia) Public Schools and suggests issues to be considered in parent involvement efforts. Pirun Sen of…
Audience Selectivity and Involvement.
ERIC Educational Resources Information Center
Perse, Elizabeth M.
A study focused on audience selectivity and involvement before and during television exposure. Two types of selectivity were considered: program selection before exposure and changing channels while viewing. The study included four indications of audience involvement: intentionality, or anticipating TV viewing; attention or focused cognitive…
Categories of Parent Involvement.
ERIC Educational Resources Information Center
Bauch, Jerold P.
1994-01-01
The growing interest in effective parent involvement has produced several ways to classify or describe ways parents are or should be involved. This article reviews and evaluates Ira Gordon's systems approach, the California-based System Development Corporation's categories, Eugenia H. Berger's parental role categories, Chavkin and Williams' parent…
Commericial Involvement in Intramurals.
ERIC Educational Resources Information Center
Maas, Gerry
Sport in general has long had ties with commercial interests, the most popular and widespread involving publicity. Intramural sports programs, however, have not cultivated many commercial involvements in publicity. The approach in intramural sports advertising is simple. A commercial interest pays for space or time in a given communication media…
Management of foreskin problems.
Lafferty, P M; MacGregor, F B; Scobie, W G
1991-01-01
One hundred consecutive cases of boys with foreskin problems referred to local paediatric surgeons in the Edinburgh area were studied. Fifty five underwent circumcision and the remainder were managed more conservatively with or without the use of local or general anaesthetic. Although sometimes avoiding general anaesthetic, the more conservative methods involved more frequent visits to the clinic, a larger number of complications, and a longer follow up period. Despite the vogue for conservatism, circumcision still has an important part to play in the management of troublesome foreskins in children. PMID:2053790
Respiratory problems in acromegaly.
Murrant, N J; Gatland, D J
1990-01-01
Death from respiratory causes in acromegaly is three times more common than in the general population and is most often the result of upper airways obstruction, although less commonly pulmonary dysfunction and disturbance of the central nervous system may occur. These factors may be found alone or in combination. Despite several reports of laryngeal involvement, upper airway obstruction in acromegaly is usually regarded as being due to macroglossia and pharyngeal soft tissue hypertrophy. We present four cases of acromegaly in which tracheostomy was required for laryngeal obstruction, with a review of the literature concerning the nature of respiratory problems in acromegaly.
Mathematical problem solving by analogy.
Novick, L R; Holyoak, K J
1991-05-01
We report the results of 2 experiments and a verbal protocol study examining the component processes of solving mathematical word problems by analogy. College students first studied a problem and its solution, which provided a potential source for analogical transfer. Then they attempted to solve several analogous problems. For some problems, subjects received one of a variety of hints designed to reduce or eliminate the difficulty of some of the major processes hypothesized to be involved in analogical transfer. Our studies yielded 4 major findings. First, the process of mapping the features of the source and target problems and the process of adapting the source solution procedure for use in solving the target problem were clearly distinguished: (a) Successful mapping was found to be insufficient for successful transfer and (b) adaptation was found to be a major source of transfer difficulty. Second, we obtained direct evidence that schema induction is a natural consequence of analogical transfer. The schema was found to co-exist with the problems from which it was induced, and both the schema and the individual problems facilitated later transfer. Third, for our multiple-solution problems, the relation between analogical transfer and solution accuracy was mediated by the degree of time pressure exerted for the test problems. Finally, mathematical expertise was a significant predictor of analogical transfer, but general analogical reasoning ability was not. The implications of the results for models of analogical transfer and for instruction were considered.
Attributes Heeded When Representing an Osmosis Problem.
ERIC Educational Resources Information Center
Zuckerman, June Trop
Eighteen high school science students were involved in a study to determine what attributes in the problem statement they need when representing a typical osmosis problem. In order to realize this goal students were asked to solve problems aloud and to explain their answers. Included as a part of the results are the attributes that the students…
Inverse heat conduction problems
NASA Astrophysics Data System (ADS)
Orlande, Helcio Rangel Barreto
We present the solution of the following inverse problems: (1) Inverse Problem of Estimating Interface Conductance Between Periodically Contacting Surfaces; (2) Inverse Problem of Estimating Interface Conductance During Solidification via Conjugate Gradient Method; (3) Determination of the Reaction Function in a Reaction-Diffusion Parabolic Problem; and (4) Simultaneous Estimation of Thermal Diffusivity and Relaxation Time with Hyperbolic Heat Conduction Model. Also, we present the solution of a direct problem entitled: Transient Thermal Constriction Resistance in a Finite Heat Flux Tube. The Conjugate Gradient Method with Adjoint Equation was used in chapters 1-3. The more general function estimation approach was treated in these chapters. In chapter 1, we solve the inverse problem of estimating the timewise variation of the interface conductance between periodically contacting solids, under quasi-steady-state conditions. The present method is found to be more accurate than the B-Spline approach for situations involving small periods, which are the most difficult on which to perform the inverse analysis. In chapter 2, we estimate the timewise variation of the interface conductance between casting and mold during the solidification of aluminum. The experimental apparatus used in this study is described. In chapter 3, we present the estimation of the reaction function in a one dimensional parabolic problem. A comparison of the present function estimation approach with the parameter estimation technique, wing B-Splines to approximate the reaction function, revealed that the use of function estimation reduces the computer time requirements. In chapter 4 we present a finite difference solution for the transient constriction resistance in a cylinder of finite length with a circular contact surface. A numerical grid generation scheme was used to concentrate grid points in the regions of high temperature gradients in order to reduce discretization errors. In chapter 6, we
Hand involvement in multiple hereditary exostosis.
Wood, V E; Molitor, C; Mudge, M K
1990-11-01
In summary, patients with multiple hereditary exostosis often inherit hand involvement but rarely show hand deformity. The principal area of involvement appears to be around the MCP joint but the PIP joint is the most common area of deformity. Metacarpal shortening usually does not cause functional problems and need not be treated. Angular deformity, though rare, does cause problems and needs surgical treatment. Unfortunately, there is no evidence that prevention of deformity is possible by early excision of osteochondromas. Treatment, therefore, requires both osteochondroma excision and closing-wedge corrective osteotomy.
Many men have sexual problems. They become more common as men age. Problems can include Erectile dysfunction Reduced or lost interest in sex ... problems may also be factors. Occasional problems with sexual function are common. If problems last more than ...
Community Involvement Training Program
A dynamic training event that brings together more than 450 people from EPA and the Agency’s partners and stakeholders who plan and implement environmental community involvement, partnership, stewardship, outreach, and education programs, t
[Heart involvement in sarcoglycanopathies].
Fayssoil, A; Nardi, O; Orlikowski, D; Annane, D
2012-11-01
Sarcoglycanopathies (SG) are autosomic recessive muscular dystrophies, secondary to mutations of the sarcoglycan complex. Clinical pictures include muscle weakness affecting mainly the proximal limb girdle musculature. We review heart involvement in this group of disease.
Consumer Involvement in Rehabilitation
ERIC Educational Resources Information Center
Daniels, Susan
1976-01-01
With the emphasis on consumer involvement in the Rehabilitation Act of 1973, changes in the counseling relationship must occur. This article discusses new interaction patterns for consumer and counselor. (Author)
[Ethical problems in organ transplantation].
Valenta, J; Treska, V; Hasman, D
1999-02-01
Organ transplantation is an accepted therapeutic method with good results, but it is connected with many not only medical but also ethical problems. One of the most important problems is the donor programme. In cadaverous donors the main ethical and legal question is the decision who can issue the consent with organ retrieval; in living donors it is the problem of motivation and financial compensation. Allocation of organs with low compatibility or from non-ideal donors, and the recipient's consent in these cases may involve difficult decisions.
Vasculitis and gastrointestinal involvement.
Casella, G; Bronzino, B; Cutrino, L; Montani, N; Somma, A; Baldini, V
2006-06-01
The incidence of gastrointestinal involvement is relatively observed in patients with vasculitis processes. Vasculitis can be primary (necrotising or hypersensitivity) or secondary to another primary disease. Gastrointestinal involvement is present in up to 50% of the various forms of systemic vasculitis. Primary or secondary vasculitic process, according to the classification in necrotizing and hypersensitivity vasculitis, are described in this paper. A review of the literature on the the subject is also presented.
Calculation of complex equilibria involving vaporization into vacuum
NASA Technical Reports Server (NTRS)
Paule, R. C.
1974-01-01
A simplified, direct approach is presented to the description of complex equilibria involving vaporization into vacuum. Emphasis is on the basic problem-solving process and on modification of existing techniques. Sequential solutions are presented to problems involving purification of a melt by vaporization into vacuum. The effects of concentration of melt and oxygen partial pressures on vaporization rates are demonstrated.
Sediment problems in urban areas
Guy, Harold P.
1970-01-01
One obstacle to a scientific recognition and an engineering solution to sediment-related environmental problems is that such problems are bound in conflicting and generally undefinable political and institutional restraints. Also, some of the difficulty may involve the fact that the scientist or engineer, because of his relatively narrow field of investigation, cannot always completely envision the less desirable effects of his work and communicate alternative solutions to the public. For example, the highway and motor-vehicle engineers have learned how to provide the means by which one can transport himself from one point to another with such great efficiency that a person's employment in this country is now commonly more than 5 miles from his residence. However, providing such efficient personal transport has created numerous serious environmental problems. Obstacles to recognition of and action to control sediment problems in and around urban areas are akin to other environmental problems with respect to the many scientific, engineering, economic, and social aspects.
NASA Astrophysics Data System (ADS)
Ohno, Shin-ya; Momose, Tatsuya; Ochiai, Toshiyuki; Suzuki, Takanori; Tanaka, Masatoshi
2017-08-01
The weak adsorption state of CO molecules on a Si(001)-c(4×2) surface at 110 K is investigated by means of reflectance difference spectroscopy (RDS). We observe repeated cycles of the increase and decrease in the RD intensity during CO exposure and after CO cessation. The decay process after CO cessation is analyzed by fitting the resulting data with an exponential function. The decay constant is evaluated to be ∼70-80 s, corresponding to the CO adsorption energies of ∼0.2-0.3 eV. The results indicate that a metastable species exists at 110 K during CO exposure. Theoretical calculations suggest that the physisorbed state is associated with this novel phenomenon.
Kucuk, Y.; Boztosun, I.; Keeley, N.
2009-06-15
The elastic scattering of the halo nucleus {sup 6}He from heavy targets at incident energies near the Coulomb barrier displays a marked deviation from the standard Fresnel-type diffraction behavior. This deviation is due to the strong Coulomb dipole breakup coupling produced by the Coulomb field of the heavy target, a specific feature of the nuclear structure of {sup 6}He. We have performed Continuum Discretized Coupled Channels calculations for the elastic scattering of {sup 6}He and {sup 6}Li from {sup 58}Ni, {sup 120}Sn, {sup 144}Sm, {sup 181}Ta and {sup 208}Pb targets in order to determine the range of Z{sub T} where this nuclear-structure specific coupling effect becomes manifest. We find that the strong Coulomb dipole breakup coupling effect is only clearly experimentally distinguishable for targets of Z{sub T}{approx_equal}80.
Horiuchi, W.; Suzuki, Y.; Capel, P.; Baye, D.
2010-02-15
A candidate of a neutron-halo nucleus, {sup 31}Ne, contains a single neutron in the pf shell. Within the Glauber and eikonal models, we analyze reactions used to study {sup 31}Ne. We show in a {sup 30}Ne+n model that the magnitudes of the total reaction and above all of the one-neutron removal cross sections of {sup 31}Ne on {sup 12}C and {sup 208}Pb targets strongly depend on the orbital angular momentum of the neutron, thereby providing us with efficient ways to determine both the spin-parity and structure of the ground state of {sup 31}Ne. Besides these inclusive observables, we also calculate energy and parallel-momentum distributions for the breakup of {sup 31}Ne and show their strong dependence on the orbital of the valence neutron in the bound state of {sup 31}Ne.
NASA Astrophysics Data System (ADS)
Zinn, Sabrina; Betz, Thomas; Medcraft, Chris; Schnell, Melanie
2015-06-01
The rotational spectrum of trans-cinnamaldehyde ((2E)-3-phenylprop-2-enal) has been obtained with chirped-pulse microwave spectroscopy in the frequency range of 2 - 8.5 GHz. The odorant molecule is the essential component in cinnamon oil and causes the characteristic smell. In the measured high-resolution spectrum, we were able to assign the rotational spectra of two conformers of trans-cinnamaldehyde as well as all singly 13C-substituted species of the lowest-energy conformer in natural abundance. Two different methods were used to determine the structure from the rotational constants, which will be compared within this contribution. In addition, the current progress of studying ether-alcohol complexes, aiming at an improved understanding of the interplay between hydrogen bonding and dispersion interaction, will be reported. Here, a special focus is placed on the complexes of diphenylether with small aliphatic alcohols.
Chen, Ying; Bylaska, Eric J.; Weare, John H.
2017-03-31
Many important geochemical and biogeochemical reactions occur in the mineral/formation water interface of the highly abundant mineral, goethite (α-Fe(OOH). Ab-initio molecular dynamics (AIMD) simulations of the goethite α-FeOOH (100) surface and the structure, water bond formation and dynamics of water molecules in the mineral/aqueous interface are presented. Here, several exchange correlation functionals were employed (PBE96, PBE96+Grimme, and PBE0) in the simulations of a (3 x 2) goethite surface with 65 absorbed water molecules in a 3D-periodic supercell (a=30 Å, FeOOH slab ~12 Å thick, solvation layer ~18 Å thick).
Woon, D.E.; Peterson, K.A.; Dunning, T.H. , Jr.
1998-08-01
The interaction of Ar with H{sub 2} and HCl has been studied using Mo/ller{endash}Plesset perturbation theory (MP2, MP3, MP4) and coupled-cluster [CCSD, CCSD(T)] methods with augmented correlation consistent basis sets. Basis sets as large as triply augmented quadruple zeta quality were used to investigate the convergence trends. Interaction energies were determined using the supermolecule approach with the counterpoise correction to account for basis set superposition error. Comparison with the available empirical potentials finds excellent agreement for both binding energies and transition state. For Ar{endash}H{sub 2}, the estimated complete basis set (CBS) limits for the binding energies of the two equivalent minima and the connecting transition state (TS) are, respectively, 55 and 47thinspcm{sup {minus}1} at the MP4 level and 54 and 46thinspcm{sup {minus}1} at the CCSD(T) level, respectively [the XC(fit) empirical potential of Bissonnette {ital et al.} [J. Chem. Phys. {bold 105}, 2639 (1996)] yields 56.6 and 47.8thinspcm{sup {minus}1} for H{sub 2} (v=0)]. The estimated CBS limits for the binding energies of the two minima and transition state of Ar{endash}HCl are 185, 155, and 109thinspcm{sup {minus}1} at the MP4 level and 176, 147, and 105thinspcm{sup {minus}1} at the CCSD(T) level, respectively [the H6(4,3,0) empirical potential of Hutson [J. Phys. Chem. {bold 96}, 4237 (1992)] yields 176.0, 148.3, and 103.3thinspcm{sup {minus}1} for HCl (v=0)]. Basis sets containing diffuse functions of (dfg) symmetries were found to be essential for accurately modeling these two complexes, which are largely bound by dispersion and induction forces. Highly correlated wave functions were also required for accurate results. This was found to be particularly true for ArHCl, where significant differences in calculated binding energies were observed between MP2, MP4, and CCSD(T). {copyright} {ital 1998 American Institute of Physics.}
NASA Astrophysics Data System (ADS)
Kafader, Jared O.; Ray, Manisha; Raghavachari, Krishnan; Jarrold, Caroline Chick
2016-02-01
Results of a systematic comparison of the MoxOy- + H2O and WxOy- + H2O reaction rate coefficients are reported and compared to previous experimental and computational studies on these reactions. WxOy- clusters undergo more direct oxidation by water to yield WxOy+1- + H2, while for MoxOy- clusters, production of MoxOyH2- (trapped intermediates in the oxidation reaction) is comparatively more prevalent. However, MoxOy- clusters generally have higher rate coefficients than analogous WxOy- clusters if MoxOy+1H2- formation is included. Results of calculations on the M2Oy- + H2O (M = Mo, W; y = 4, 5) reaction entrance channel are reported. They include charge-dipole complexes formed from long-range interactions, and the requisite conversion to a Lewis acid-base complex that leads to MxOy+1H2- formation. The results predict that the Lewis acid-base complex is more strongly bound for MoxOy- clusters than for WxOy- clusters. The calculated free energies along this portion of the reaction path are also consistent with the modest anti-Arrhenius temperature dependence measured for most MoxOy- + H2O reactions, and the WxOy- + H2O reaction rate coefficients generally being constant over the temperature range sampled in this study. For clusters that exhibit evidence of both water addition and oxidation reactions, increasing the temperature increases the branching ratio toward oxidation for both species. A more direct reaction path to H2 production may therefore become accessible at modest temperatures for certain cluster stoichiometries and structures.
Weakly Bound and Strongly Interacting: NbSe2 and 1T-TaS2 in the 2D Limit
NASA Astrophysics Data System (ADS)
Tsen, Adam
The layered metallic dichalcogenides are known to exhibit rich collective electron phases such as charge density waves, spin density waves, and superconductivity. In the past, studies on graphene and various semiconducting dichalcogenides have shown that taking layered materials to their physical two-dimensional (2D) limit leads to fundamental changes in band structure, allowing for a powerful experimental knob to tune for electronic functionality. In contrast, due to their instability in the ambient environment, the effect of thickness control over such collective electron phases has been largely unexplored in metallic systems. We have recently demonstrated a new experimental platform for the isolation and assembly of environmentally sensitive 2D materials in inert atmosphere. I will discuss our recent studies of the charge density wave material 1T-TaS2 and superconducting NbSe2 in the atomically thin limit, made possible using this technique. For 1T-TaS2, we find that the lock-in transition to commensurate charge ordering becomes increasingly metastable for reduced thickness, allowing for all-electrical control over this phase transition in the 2D state. In NbSe2, a small magnetic field induces a transition to a quantum metallic phase, the resistivity of which obeys a unique field-scaling property. These methods and experiments open new doors for the study of other correlated 2D materials in the immediate future.
NASA Astrophysics Data System (ADS)
Papp, Dóra; Szidarovszky, Tamás; Császár, Attila G.
2017-09-01
The quasi-variational quantum chemical protocol and code GENIUSH [E. Mátyus et al., J. Chem. Phys. 130, 134112 (2009) and C. Fábri et al., J. Chem. Phys. 134, 074105 (2011)] has been augmented with the complex absorbing potential (CAP) technique, yielding a method for the determination of rovibrational resonance states. Due to the effective implementation of the CAP technique within GENIUSH, the GENIUSH-CAP code is a powerful tool for the study of important dynamical features of arbitrary-sized molecular systems with arbitrary composition above their first dissociation limit. The GENIUSH-CAP code has been tested and validated on the H2He+ cation: the computed resonance energies and lifetimes are compared to those obtained with a previously developed triatomic rovibrational resonance-computing code, D2FOPI-CCS [T. Szidarovszky and A. G. Császár Mol. Phys. 111, 2131 (2013)], utilizing the complex coordinate scaling method. A unique feature of the GENIUSH-CAP protocol is that it allows the simple implementation of reduced-dimensional dynamical models. To prove this, resonance energies and lifetimes of the H2ṡCO van der Waals complex have been computed utilizing a four-dimensional model (freezing the two monomer stretches), and a related potential energy surface, of the complex.
NASA Astrophysics Data System (ADS)
Bailey, David H.; Frolov, Alexei M.
2003-12-01
Since the above paper was published we have received a suggestion from T K Rebane that our variational energy, -402.261 928 652 266 220 998 au, for the 3S(L = 0) state from table 4 (right-hand column) is wrong in the fourth and fifth decimal digits. Our original variational energies were E(2000) = -402.192 865 226 622 099 583 au and E(3000) = -402.192 865 226 622 099 838 au. Unfortunately, table 4 contains a simple typographic error. The first two digits after the decimal point (26) in the published energies must be removed. Then the results exactly coincide with the original energies. These digits (26) were left in table 4 from the original version, which also included the 2S(L = 0) states of the helium-muonic atoms. A similar typographic error was found in table 4 of another paper by A M Frolov (2001 J. Phys. B: At. Mol. Opt. Phys. 34 3813). The computed ground state energy for the ppµ muonic molecular ion was -0.494 386 820 248 934 546 94 mau. In table 4 of that paper the first figure '8' (fifth digit after the decimal point) was lost from the energy value presented in this table. We wish to thank T K Rebane of the Fock Physical Institute in St Petersburg for pointing out the misprint related to the helium(4)-muonic atom.
Computational solution of chemistry problems
NASA Technical Reports Server (NTRS)
Ake, Robert L.
1989-01-01
AB initio quantum chemical techniques have been used to investigate weakly bound complexes of H2O and SO2. An energy gradient program was used to locate stable structures for the H2O, SO2 complexes, and SCF calculations were carried out to determine the binding energies of complexes with multiple water molecules. A 4-31G basis set was used for most potential energy searches. More accurate basis sets including a generally contracted basis set with d orbitals on the sulfur were used for geometry and binding energy verification. For single water complexes, five different stable geometries were located with binding energies between 4 and 11 Kcal mol(-1), suggesting a binding shell for H2O around SO2 and a mechanism for the formation of an SO2-containing water droplet. Calculations on one of the complexes utilizing a larger double zeta basis and d functions on the sulfur atom lead to adjusted binding energies in the range 3 to 8 Kcal mol(-1). Very little charge transfer between SO2 and H2O was present. Addition of more than one H2O was found to be energetically favorable although the addition of the fourth water in certain geometries did not increase the stability of the complex. An alternative mechanism for the tropospheric gas phase production of acid rain is suggested.
Handling behavior problems in the practice setting.
Landsberg, Gary M; Shaw, Julie; Donaldson, Jean
2008-09-01
The veterinary clinic plays a critical role in the prevention and treatment of behavior problems. If behavior problems do begin to emerge, the veterinary clinic can help determine who can advise and guide the owners most practically to improve or resolve the problem. This help might involve the veterinarian, a behavioral technician, a trained staff member, an appropriate trainer, or some combination of these persons. This article reviews how these professional roles might be integrated, depending on the complexity of the problem.
The worldwide "wildfire" problem.
Gill, A Malcolm; Stephens, Scott L; Cary, Geoffrey J
2013-03-01
The worldwide "wildfire" problem is headlined by the loss of human lives and homes, but it applies generally to any adverse effects of unplanned fires, as events or regimes, on a wide range of environmental, social, and economic assets. The problem is complex and contingent, requiring continual attention to the changing circumstances of stakeholders, landscapes, and ecosystems; it occurs at a variety of temporal and spatial scales. Minimizing adverse outcomes involves controlling fires and fire regimes, increasing the resistance of assets to fires, locating or relocating assets away from the path of fires, and, as a probability of adverse impacts often remains, assisting recovery in the short-term while promoting the adaptation of societies in the long-term. There are short- and long-term aspects to each aspect of minimization. Controlling fires and fire regimes may involve fire suppression and fuel treatments such as prescribed burning or non-fire treatments but also addresses issues associated with unwanted fire starts like arson. Increasing the resistance of assets can mean addressing the design and construction materials of a house or the use of personal protective equipment. Locating or relocating assets can mean leaving an area about to be impacted by fire or choosing a suitable place to live; it can also mean the planning of land use. Assisting recovery and promoting adaptation can involve insuring assets and sharing responsibility for preparedness for an event. There is no single, simple, solution. Perverse outcomes can occur. The number of minimizing techniques used, and the breadth and depth of their application, depends on the geographic mix of asset types. Premises for policy consideration are presented.
Musculoskeletal involvement in sarcoidosis*, **
Nessrine, Akasbi; Zahra, Abourazzak Fatima; Taoufik, Harzy
2014-01-01
Sarcoidosis is a multisystem inflammatory disorder of unknown cause. It most commonly affects the pulmonary system but can also affect the musculoskeletal system, albeit less frequently. In patients with sarcoidosis, rheumatic involvement is polymorphic. It can be the presenting symptom of the disease or can appear during its progression. Articular involvement is dominated by nonspecific arthralgia, polyarthritis, and Löfgren's syndrome, which is defined as the presence of lung adenopathy, arthralgia (or arthritis), and erythema nodosum. Skeletal manifestations, especially dactylitis, appear mainly as complications of chronic, multiorgan sarcoidosis. Muscle involvement in sarcoidosis is rare and usually asymptomatic. The diagnosis of rheumatic sarcoidosis is based on X-ray findings and magnetic resonance imaging findings, although the definitive diagnosis is made by anatomopathological study of biopsy samples. Musculoskeletal involvement in sarcoidosis is generally relieved with nonsteroidal anti-inflammatory drugs or corticosteroids. In corticosteroid-resistant or -dependent forms of the disease, immunosuppressive therapy, such as treatment with methotrexate or anti-TNF-α, is employed. The aim of this review was to present an overview of the various types of osteoarticular and muscle involvement in sarcoidosis, focusing on their diagnosis and management. PMID:24831403
Management of hip involvement in ankylosing spondylitis.
Guan, Mingqiang; Wang, Jian; Zhao, Liang; Xiao, Jun; Li, Zhihan; Shi, Zhanjun
2013-08-01
Ankylosing spondylitis (AS) is an inflammatory rheumatologic disease characterized by inflammation and progressive structural damage of the affected joints. Hip involvement often results in severe deformities and significant impairment on function. Although, tremendous progress has been made in conservative management for AS, effective prevention strategies for hip involvement and long-term need for total hip arthroplasty (THA) remain indefinite. When hip involvement has progressed to intractable pain and disability, THA is still the most effective treatment strategy to relieve pain and restore function. However, certain AS-specific problems regarding "preoperative preparation," "intraoperative difficulties," "perioperative pharmacological management," "postoperative physiotherapy," "operation benefits," and "operation complications" need more concern and further discussion.
The Legal Audit: Preventing Problems.
ERIC Educational Resources Information Center
Perlman, Daniel H.
1987-01-01
Suffolk University initiated two audits that proved beneficial: a legal audit and an insurance audit. A legal audit involves having an attorney review a college's contracts, personnel handbooks, catalogs, etc., in order to anticipate and prevent problems. An insurance audit reviews an institution's risk coverage. (MLW)
Breathing Problems: An Individualized Program.
ERIC Educational Resources Information Center
Vodola, Thomas M.
As one of the components of the Project ACTIVE (All Children Totally Involved Exercising) Teacher Training Model Kit, the manual is designed to enable the educator to organize, conduct, and evaluate individualized-personalized physical education programs for children (prekindergarten through high school) with breathing problems. An introductory…
The Legal Audit: Preventing Problems.
ERIC Educational Resources Information Center
Perlman, Daniel H.
1987-01-01
Suffolk University initiated two audits that proved beneficial: a legal audit and an insurance audit. A legal audit involves having an attorney review a college's contracts, personnel handbooks, catalogs, etc., in order to anticipate and prevent problems. An insurance audit reviews an institution's risk coverage. (MLW)
Family Problems and Youth Unemployment.
ERIC Educational Resources Information Center
de Goede, Martijn; Spruijt, Ed; Maas, Cora; Duindam, Vincent
2000-01-01
Examines how family and personal characteristics relate to the employment situation of adolescents (N=995) in Denmark. Results show that parental divorce, parental unemployment (only for males), low parental affective involvement, and adolescent relationship problems were related to youth unemployment, but educational career and work commitment…
Teaching Math. Extending Problem Solving.
ERIC Educational Resources Information Center
May, Lola
1996-01-01
Describes four teaching activities to help children extend math problem-solving skills by using their own questions. Activities involve using a chart and symbols to develop equations adding up to 12, going on an imaginary shopping trip, using shapes to represent dollar amounts, using the date on a penny to engage in various mathematical…
Adolescent Involvement in Discipline Decision Making
ERIC Educational Resources Information Center
Deroma, Virginia M.; Lassiter, Kerry S.; Davis, Virginia A.
2004-01-01
This study examined the influence of (a) low, medium, or high adolescent involvement (degree to which adolescent input was solicited in determining consequence) in discipline decisions and (b) parental versus adolescent focus of impact of behavior problem (parent emphasized inconvenience to either self or adolescent). After viewing videotaped…
Kidney involvement in systemic sclerosis.
Steen, Virginia D
2014-10-01
Kidney involvement in systemic sclerosis (SSc) is primarily manifested by scleroderma renal crisis (SRC). Formerly, it was the most severe complication in scleroderma and was the most frequent cause of death in these patients. More than 30years ago, with the development of angiotensin converting enzyme (ACE) inhibitors, SRC became a very treatable complication of scleroderma. Although there are still many patients who do not survive and have poor outcomes, early diagnosis of renal crisis and prompt therapeutic intervention can achieve excellent outcomes. Renal abnormalities independent of renal crisis have been noted, but can usually be attributed to other problems. Further understanding of the pathogenesis of renal disease in scleroderma may lead to additional improvement in the therapy of renal crisis and perhaps the disease in general. This chapter reviews the pathogenesis, clinical setting, and therapy of this serious complication of SSc. Copyright © 2014. Published by Elsevier Masson SAS.
Reaching Parents Through Involvement
ERIC Educational Resources Information Center
Schmerber, Ronald J.
1974-01-01
The parent involvement program evolved from the needs of parents. Basic to the program is the concept of parenting, which implies taking positive action to facilitate and meet the needs of the children ahe family. Parents participate in the development, implementation, and evaluation of their child's program. (Author)
Community Involvement in Education.
ERIC Educational Resources Information Center
Patterson, Bill; Horwood, Bert
During the 20th century, the involvement of communities in education has deteriorated, and the school and the community have evolved into separate worlds. This chapter describes ways in which a typical high school has increased its interactions with its own community. Those interactions have two dimensions: to bring the community into the school…
Rethinking Parent Involvement.
ERIC Educational Resources Information Center
Vandergrift, Judith A.; Greene, Andrea L.
1992-01-01
Arizona At-Risk Pilot Project results suggest most effective means to involve parents are those that establish personal rapport between someone from the school and a parent and do not initially require high levels of commitment or participation. The "ideal" parent may be hard to find, but getting to know parents individually and…
Editor's message: Student involvement
Bill Block
2012-01-01
In the initial Editor's Message of this volume, I stated my intent to involve more students in the publication process. A number of people commented on it being a good idea, but only a couple have followed up. One was Paul Krausman, President of The Wildlife Society. We matched graduate students from the University of Montana wildlife program with manuscripts...
Rethinking Parent Involvement.
ERIC Educational Resources Information Center
Vandergrift, Judith A.; Greene, Andrea L.
1992-01-01
Arizona At-Risk Pilot Project results suggest most effective means to involve parents are those that establish personal rapport between someone from the school and a parent and do not initially require high levels of commitment or participation. The "ideal" parent may be hard to find, but getting to know parents individually and…
ERIC Educational Resources Information Center
Butts, Vickie; Finch, Patty A.
1985-01-01
Describes a parental involvement program in reading, writing, and human education. The project consists of caring for Clifford, a stuffed toy dog, on a rotated basis by first grade students. Books and pet care items accompany Clifford and provide an opportunity for parent and child to work together. (ML)
ERIC Educational Resources Information Center
Music Educators Journal, 1992
1992-01-01
Presents the attempts of four teachers to get parents involved in and excited about school music. Includes a description of a school concert that included a performance by band parents; parents clubs for orchestra, band, or choral groups; newsletters; and a band class in which parents learned to play their child's instrument. (DK)
ERIC Educational Resources Information Center
Butts, Vickie; Finch, Patty A.
1985-01-01
Describes a parental involvement program in reading, writing, and human education. The project consists of caring for Clifford, a stuffed toy dog, on a rotated basis by first grade students. Books and pet care items accompany Clifford and provide an opportunity for parent and child to work together. (ML)
Parent Involvement. Research Brief
ERIC Educational Resources Information Center
Walker, Karen
2007-01-01
What are some ways in which to get parents meaningfully involved in their child's high school? According to the research, the most successful programs are those that provide a variety of ways in which parents can be actively engaged in their child's academic life. Joyce Epstein, Director of the National Network of Partnership Schools, out of Johns…
Multigrid method for stability problems
NASA Technical Reports Server (NTRS)
Taasan, Shlomo
1988-01-01
The problem of calculating the stability of steady state solutions of differential equations is treated. Leading eigenvalues (i.e., having maximal real part) of large matrices that arise from discretization are to be calculated. An efficient multigrid method for solving these problems is presented. The method begins by obtaining an initial approximation for the dominant subspace on a coarse level using a damped Jacobi relaxation. This proceeds until enough accuracy for the dominant subspace has been obtained. The resulting grid functions are then used as an initial approximation for appropriate eigenvalue problems. These problems are being solved first on coarse levels, followed by refinement until a desired accuracy for the eigenvalues has been achieved. The method employs local relaxation on all levels together with a global change on the coarsest level only, which is designed to separate the different eigenfunctions as well as to update their corresponding eigenvalues. Coarsening is done using the FAS formulation in a non-standard way in which the right hand side of the coarse grid equations involves unknown parameters to be solved for on the coarse grid. This in particular leads to a new multigrid method for calculating the eigenvalues of symmetric problems. Numerical experiments with a model problem demonstrate the effectiveness of the method proposed. Using an FMG algorithm a solution to the level of discretization errors is obtained in just a few work units (less than 10), where a work unit is the work involved in one Jacobi relization on the finest level.
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Gang Involvement and Membership among Homeless and Runaway Youth.
ERIC Educational Resources Information Center
Yoder, Kevin A.; Whitbeck, Les B.; Hoyt, Dan R.
2003-01-01
Assessed the extent of gang involvement among homeless and runaway youth, comparing gang members, gang-involved youth (not members), and non-gang youth on several dimensions. Interview data indicated that 15.4 percent of the youth were gang members and 32.2 percent were involved in gangs. These youth reported more family problems and school…
Gang Involvement and Membership among Homeless and Runaway Youth.
ERIC Educational Resources Information Center
Yoder, Kevin A.; Whitbeck, Les B.; Hoyt, Dan R.
2003-01-01
Assessed the extent of gang involvement among homeless and runaway youth, comparing gang members, gang-involved youth (not members), and non-gang youth on several dimensions. Interview data indicated that 15.4 percent of the youth were gang members and 32.2 percent were involved in gangs. These youth reported more family problems and school…
[Thyroid involvement of sarcoidosis].
Uto, Tomohiro; Inui, Naoki; Miyazaki, Hiroo; Matsushima, Sayomi; Kuroishi, Shigeki; Hashimoto, Dai; Naito, Tateaki; Nakamura, Yutaro; Sato, Jun; Suda, Takafumi; Chida, Kingo
2008-08-01
A 54-year-old woman was found to have abnormal shadows on her chest radiograph taken on an annual medical examination. The chest radiograph showed multiple nodules in the bilateral middle and lower lung fields accompanied with bilateral hilar lymphadenopathy. A computed tomography of the neck and chest revealed nodules in her right middle lobe and bilateral lower lobes with an enlarged thyroid. A metastatic malignant disease involving both thyroid and lungs was suspected, therefore thyroid and lung biopsies were performed. The histological examination of the thyroid and the lung specimens revealed non-caseating epithelioid cell granulomas which were compatible with sarcoidosis. Although the thyroid involvement of sarcoidosis is rare, it should be included in the differential diagnosis with patients with thyroid swelling.
ERIC Educational Resources Information Center
Karatas, Ilhan; Baki, Adnan
2013-01-01
Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educating students as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum.…
Characteristics of Moral Problems as Formulated by Gifted Adolescents.
ERIC Educational Resources Information Center
Colangelo, Nicholas
1982-01-01
Gifted adolescents from grades 9-12 were asked to generate stories involving a moral problem and to provide a solution. Half of the moral problems written involved friendship or a love relationship; 92 percent of the students were able to give guidelines for solutions to their moral problems. (RM)
Class and Home Problems: Optimization Problems
ERIC Educational Resources Information Center
Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard
2011-01-01
Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…
Class and Home Problems: Optimization Problems
ERIC Educational Resources Information Center
Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard
2011-01-01
Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…
Group problems in problem-based learning.
Hendry, Graham D; Ryan, Greg; Harris, Jennifer
2003-11-01
Successful small-group learning in problem-based learning (PBL) educational programmes relies on functional group processes. However, there has been limited research on PBL group problems, and no studies have been conducted on problems as perceived by both students and tutors in the same educational context. The authors investigated PBL group problems in a graduate-entry medical programme, and report the most common group problems, and those that hinder students' learning the most. The possible causes of individual quietness and dominant behaviour, and potential influences that group problems may have on the tutorial process are summarized in an exploratory model of PBL group dysfunction that could be used to guide further research. Specifically, there is a need for further evidence on which to base guidelines for tutors and students to effectively manage group problems.
Endocannabinoid involvement in endometriosis
Dmitrieva, Natalia; Nagabukuro, Hiroshi; Resuehr, David; Zhang, Guohua; McAllister, Stacy L.; McGinty, Kristina A.; Mackie, Ken; Berkley, Karen J.
2010-01-01
Endometriosis is a disease common in women that is defined by abnormal extrauteral growths of uterine endometrial tissue and associated with severe pain. Partly because how the abnormal growths become associated with pain is poorly understood, the pain is difficult to alleviate without resorting to hormones or surgery, which often produce intolerable side effects or fail to help. Recent studies in a rat model and women showed that sensory and sympathetic nerve fibers sprout branches to innervate the abnormal growths. This situation, together with knowledge that the endocannabinoid system is involved in uterine function and dysfunction and that exogenous cannabinoids were once used to alleviate endometriosis-associated pain, suggests that the endocannabinoid system is involved in both endometriosis and its associated pain. Here, using a rat model, we found that CB1 cannabinoid receptors are expressed on both the somata and fibers of both the sensory and sympathetic neurons that innervate endometriosis’s abnormal growths. We further found that CB1 receptor agonists decrease, whereas CB1 receptor antagonists increase, endometriosis-associated hyperalgesia. Together these findings suggest that the endocannabinoid system contributes to mechanisms underlying both the peripheral innervation of the abnormal growths and the pain associated with endometriosis, thereby providing a novel approach for the development of badly-needed new treatments. PMID:20833475
Optimization and geophysical inverse problems
Barhen, J.; Berryman, J.G.; Borcea, L.; Dennis, J.; de Groot-Hedlin, C.; Gilbert, F.; Gill, P.; Heinkenschloss, M.; Johnson, L.; McEvilly, T.; More, J.; Newman, G.; Oldenburg, D.; Parker, P.; Porto, B.; Sen, M.; Torczon, V.; Vasco, D.; Woodward, N.B.
2000-10-01
A fundamental part of geophysics is to make inferences about the interior of the earth on the basis of data collected at or near the surface of the earth. In almost all cases these measured data are only indirectly related to the properties of the earth that are of interest, so an inverse problem must be solved in order to obtain estimates of the physical properties within the earth. In February of 1999 the U.S. Department of Energy sponsored a workshop that was intended to examine the methods currently being used to solve geophysical inverse problems and to consider what new approaches should be explored in the future. The interdisciplinary area between inverse problems in geophysics and optimization methods in mathematics was specifically targeted as one where an interchange of ideas was likely to be fruitful. Thus about half of the participants were actively involved in solving geophysical inverse problems and about half were actively involved in research on general optimization methods. This report presents some of the topics that were explored at the workshop and the conclusions that were reached. In general, the objective of a geophysical inverse problem is to find an earth model, described by a set of physical parameters, that is consistent with the observational data. It is usually assumed that the forward problem, that of calculating simulated data for an earth model, is well enough understood so that reasonably accurate synthetic data can be generated for an arbitrary model. The inverse problem is then posed as an optimization problem, where the function to be optimized is variously called the objective function, misfit function, or fitness function. The objective function is typically some measure of the difference between observational data and synthetic data calculated for a trial model. However, because of incomplete and inaccurate data, the objective function often incorporates some additional form of regularization, such as a measure of smoothness
A Boundary Value Problem for Introductory Physics?
ERIC Educational Resources Information Center
Grundberg, Johan
2008-01-01
The Laplace equation has applications in several fields of physics, and problems involving this equation serve as paradigms for boundary value problems. In the case of the Laplace equation in a disc there is a well-known explicit formula for the solution: Poisson's integral. We show how one can derive this formula, and in addition two equivalent…
Spatial Visualization in Physics Problem Solving
ERIC Educational Resources Information Center
Kozhevnikov, Maria; Motes, Michael A.; Hegarty, Mary
2007-01-01
Three studies were conducted to examine the relation of spatial visualization to solving kinematics problems that involved either predicting the two-dimensional motion of an object, translating from one frame of reference to another, or interpreting kinematics graphs. In Study 1, 60 physics-naive students were administered kinematics problems and…
Helping Ourselves: Local Solutions to Global Problems.
ERIC Educational Resources Information Center
Stokes, Bruce
Solutions to global problems such as inflation, tightening energy supplies, and deteriorating environmental quality lie at the local level where the consequences are most obvious, the motivation to get involved is most direct, and the benefits of action are most immediate. Examples of problems regarding energy, the workplace, food production,…
Taking "From Scratch" out of Problem Solving
ERIC Educational Resources Information Center
Brown, Wayne
2007-01-01
Solving problems and creating processes and procedures from the ground up has long been part of the IT department's way of operating. IT staffs will continue to encounter new problems to solve and new technologies to be implemented. They also must involve their constituents in the creation of solutions. Nonetheless, for many issues they no longer…
Creativity and Insight in Problem Solving
ERIC Educational Resources Information Center
Golnabi, Laura
2016-01-01
This paper analyzes the thought process involved in problem solving and its categorization as creative thinking as defined by psychologist R. Weisberg (2006). Additionally, the notion of insight, sometimes present in unconscious creative thinking and often leading to creative ideas, is discussed in the context of geometry problem solving. In…
Some "Real" Problems of "Virtual" Organisation.
ERIC Educational Resources Information Center
Hughes, John A.; O'Brien, Jon; Randall, Dave; Rouncefield, Mark; Tolmie, Peter
2001-01-01
An ethnographic study of organizational change in a bank considered issues surrounding virtual teamwork in virtual organizations. Problems in communication, management control, and approach to customer service were found. An underlying cause is that "virtual" work involves "real" customers, workers, and problems. (Contains 36 references.) (SK)
Solving Problems of Practice in Education.
ERIC Educational Resources Information Center
Boyd, Robert D.; Menlo, Allen
1984-01-01
Discusses the many complexities involved in the translation of scientific information in the social sciences into forms usable for solving problems of practice in education. Prescribes a series of stages to be followed from the advent of a practitioner's situational problem to the design of a response to it. (Author/JN)
Some "Real" Problems of "Virtual" Organisation.
ERIC Educational Resources Information Center
Hughes, John A.; O'Brien, Jon; Randall, Dave; Rouncefield, Mark; Tolmie, Peter
2001-01-01
An ethnographic study of organizational change in a bank considered issues surrounding virtual teamwork in virtual organizations. Problems in communication, management control, and approach to customer service were found. An underlying cause is that "virtual" work involves "real" customers, workers, and problems. (Contains 36 references.) (SK)
Local History and Problem-Based Learning
ERIC Educational Resources Information Center
Wieseman, Katherine C.; Cadwell, Doni
2005-01-01
The combination of students, local history, researching, and problem-based learning creates a powerful opportunity for learning to all involved. This article provides one example of how an elementary teacher and a teacher educator have used local resources and problem-based learning to teach a fourth grade unit about human communities and the…
Problem Solved: How To Coach Cognition.
ERIC Educational Resources Information Center
Krynock, Karoline; Robb, Louise
1999-01-01
When faced with real-world problems, students devise accurate, logical, and creative solutions using skills connecting to different subject areas. Students are intrigued by assignments involving preservation of species and design of environmentally friendly products and transit systems. Problem-based learning depends on coaching, modeling, and…
How to Generate Good Profit Maximization Problems
ERIC Educational Resources Information Center
Davis, Lewis
2014-01-01
In this article, the author considers the merits of two classes of profit maximization problems: those involving perfectly competitive firms with quadratic and cubic cost functions. While relatively easy to develop and solve, problems based on quadratic cost functions are too simple to address a number of important issues, such as the use of…
Problem Solving and Comprehension. Third Edition.
ERIC Educational Resources Information Center
Whimbey, Arthur; Lochhead, Jack
This book is directed toward increasing students' ability to analyze problems and comprehend what they read and hear. It outlines and illustrates the methods that good problem solvers use in attacking complex ideas, and provides practice in applying these methods to a variety of questions involving comprehension and reasoning. Chapter I includes a…
A Boundary Value Problem for Introductory Physics?
ERIC Educational Resources Information Center
Grundberg, Johan
2008-01-01
The Laplace equation has applications in several fields of physics, and problems involving this equation serve as paradigms for boundary value problems. In the case of the Laplace equation in a disc there is a well-known explicit formula for the solution: Poisson's integral. We show how one can derive this formula, and in addition two equivalent…
Approaching messy problems: strategies for environmental analysis
L. M. Reid; R. R. Ziemer; T. E. Lisle
1996-01-01
Environmental problems are never neatly defined. Instead, each is a tangle of interacting processes whose manifestation and interpretation are warped by the vagaries of time, weather, expectation, and economics. Each problem involves livelihoods, values, and numerous specialized disciplines. Nevertheless, federal agencies in the Pacific Northwest have been given the...
Creativity and Insight in Problem Solving
ERIC Educational Resources Information Center
Golnabi, Laura
2016-01-01
This paper analyzes the thought process involved in problem solving and its categorization as creative thinking as defined by psychologist R. Weisberg (2006). Additionally, the notion of insight, sometimes present in unconscious creative thinking and often leading to creative ideas, is discussed in the context of geometry problem solving. In…
How to Generate Good Profit Maximization Problems
ERIC Educational Resources Information Center
Davis, Lewis
2014-01-01
In this article, the author considers the merits of two classes of profit maximization problems: those involving perfectly competitive firms with quadratic and cubic cost functions. While relatively easy to develop and solve, problems based on quadratic cost functions are too simple to address a number of important issues, such as the use of…
Discovering Steiner Triple Systems through Problem Solving
ERIC Educational Resources Information Center
Sriraman, Bharath
2004-01-01
An attempt to implement problem solving as a teacher of ninth grade algebra is described. The problems selected were not general ones, they involved combinations and represented various situations and were more complex which lead to the discovery of Steiner triple systems.
Local History and Problem-Based Learning
ERIC Educational Resources Information Center
Wieseman, Katherine C.; Cadwell, Doni
2005-01-01
The combination of students, local history, researching, and problem-based learning creates a powerful opportunity for learning to all involved. This article provides one example of how an elementary teacher and a teacher educator have used local resources and problem-based learning to teach a fourth grade unit about human communities and the…
Taking "From Scratch" out of Problem Solving
ERIC Educational Resources Information Center
Brown, Wayne
2007-01-01
Solving problems and creating processes and procedures from the ground up has long been part of the IT department's way of operating. IT staffs will continue to encounter new problems to solve and new technologies to be implemented. They also must involve their constituents in the creation of solutions. Nonetheless, for many issues they no longer…
Using Programmable Calculators to Solve Electrostatics Problems.
ERIC Educational Resources Information Center
Yerian, Stephen C.; Denker, Dennis A.
1985-01-01
Provides a simple routine which allows first-year physics students to use programmable calculators to solve otherwise complex electrostatic problems. These problems involve finding electrostatic potential and electric field on the axis of a uniformly charged ring. Modest programing skills are required of students. (DH)
Mathematical Problem Solving. Issues in Research.
ERIC Educational Resources Information Center
Lester, Frank K., Jr., Ed.; Garofalo, Joe, Ed.
This set of papers was originally developed for a conference on Issues and Directions in Mathematics Problem Solving Research held at Indiana University in May 1981. The purpose is to contribute to the clear formulation of the key issues in mathematical problem-solving research by presenting the ideas of actively involved researchers. An…
Banks, Richard C.
1980-01-01
The American Ornithologists' Union and its members had an early history of involvement in public affairs and conservation activities. A very active Committee on Bird Protection was among the first of the service committees to be established. In the 1880s it gathered data on the plumage trade and worked for legislation to protect birds, preparing a model law for the protection of nongame birds that was adopted quickly by two states and later by others. As a direct result of action at the 1884 A.O.U. meeting, the forerunner of the present U.S. Fish and Wildlife Service was established as a government office. The present National Audubon Society was another outgrowth of the A.O.U.'s early conservation and educational activities. In the 1920s the A.O.U. raised funds to establish a bird sanctuary at Olney, Illinois, in honor of Robert Ridgway.
Aluminium Involvement in Neurotoxicity
Fulgenzi, Alessandro; Vietti, Daniele; Ferrero, Maria Elena
2014-01-01
The aetiology of neurodegenerative diseases (ND) seems to involve susceptibility genes and environmental factors. Toxic metals are considered major environmental pollutants. Following our study of a case of multiple sclerosis (MS) improvement due to removal of aluminium (Al) and other toxic metals, we have examined the possible relationship between Al intoxication and ND. We used the slow intravenous treatment with the chelating agent EDTA (calcium disodium ethylene diamine tetraacetic acid) (chelation test) to remove Al and detected it in the urine collected from the patients for 12 hours. Patients affected by MS represented 85.6% of total ND. Al was present in 44.8% of cases comprehensive of ND and healthy patients. Al levels were significantly higher in ND patients than in healthy subjects. We here show that treatment of patients affected by Al burden with ten EDTA chelation therapies (EDTA intravenous administration once a week) was able to significantly reduce Al intoxication. PMID:25243176
Problems in Decentralized Decision making and Computation.
1984-12-01
Wald ) problem [Teneketzis, 1983], as well as problems involving communication of zero-one messages from certain sensors to others [Ekchian and Tenney...that the development of results for pseudo-gradient algorithms leads easily to results for broader classes of algorithms, such as Kiefer- Wolfowitz ...Decentralized Wald Problem," Proceedings of the 1983 American Control Conference, San Francisco, CA. Teneketzis, D., P. Varaiya, (1984), "Consensus in
Stochastic Linear Quadratic Optimal Control Problems
Chen, S.; Yong, J.
2001-07-01
This paper is concerned with the stochastic linear quadratic optimal control problem (LQ problem, for short) for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. Some intrinsic relations among the LQ problem, the stochastic maximum principle, and the (linear) forward-backward stochastic differential equations are established. Some results involving Riccati equation are discussed as well.
... this page please turn Javascript on. Problems with Smell About Problems with Smell Our sense of smell helps us enjoy life. ... sec Click to watch this video Aging and Smell Loss Problems with smell increase as people get ...
ERIC Educational Resources Information Center
Reeves, Charles A.
2000-01-01
Uses the chicken problem for sixth grade students to scratch the surface of systems of equations using intuitive approaches. Provides students responses to the problem and suggests similar problems for extensions. (ASK)
NASA Astrophysics Data System (ADS)
Marchal, Christian
Recent research on the theory of perturbations, the analytical approach and the quantitative analysis of the three-body problem have reached a high degree of perfection. The use of electronics has aided developments in quantitative analysis and has helped to disclose the extreme complexity of the set of solutions. This accelerated progress has given new orientation and impetus to the qualitative analysis that is so complementary to the quantitative analysis. The book begins with the various formulations of the three-body problem, the main classical results and the important questions and conjectures involved in this subject. The main part of the book describes the remarkable progress achieved in qualitative analysis which has shed new light on the three-body problem. It deals with questions such as escapes, captures, periodic orbits, stability, chaotic motions, Arnold diffusion, etc. The most recent tests of escape have yielded very impressive results and border very close on the true limits of escape, showing the domain of bounded motions to be much smaller than was expected. An entirely new picture of the three-body problem is emerging, and the book reports on this recent progress. The structure of the solutions for the three-body problem lead to a general conjecture governing the picture of solutions for all Hamiltonian problems. The periodic, quasi-periodic and almost-periodic solutions form the basis for the set of solutions and separate the chaotic solutions from the open solutions.
Advancing efforts to address youth violence involvement.
Weist, M D; Cooley-Quille, M
2001-06-01
Discusses the increased public attention on violence-related problems among youth and the concomitant increased diversity in research. Youth violence involvement is a complex construct that includes violence experienced in multiple settings (home, school, neighborhood) and in multiple forms (as victims, witnesses, perpetrators, and through family members, friends, and the media). Potential impacts of such violence involvement are considerable, including increased internalizing and externalizing behaviors among youth and future problems in school adjustment and life-course development. This introductory article reviews key dimensions of youth-related violence, describes an American Psychological Association Task Force (Division 12) developed to advance relevant research, and presents examples of national resources and efforts that attempt to address this critical public health issue.
Pharmaceutical research involving the homeless.
Beauchamp, Tom L; Jennings, Bruce; Kinney, Eleanor D; Levine, Robert J
2002-10-01
Discussions of research involving vulnerable populations have left the homeless comparatively ignored. Participation by these subjects in drug studies has the potential to be upsetting, inconvenient, or unpleasant. Participation occasionally produces injury, health emergencies, and chronic health problems. Nonetheless, no ethical justification exists for the categorical exclusion of homeless persons from research. The appropriate framework for informed consent for these subjects of pharmaceutical research is not a single event of oral or written consent, but a multi-staged arrangement of disclosure, dialogue, and permission-giving. Payments and other rewards in biomedical research raise issues of whether it is ethical to offer inducements to the homeless in exchange for participation in drug studies. Such inducements can influence desperate persons who are seriously lacking in resources. The key is to strike a balance between a rate of payment high enough that it does not exploit subjects by underpayment and low enough that it does not create an irresistible inducement. This proposal does not underestimate the risks of research, which are often overestimated and need to be appraised in light of the relevant empirical literature.
Nail involvement in psoriatic arthritis.
Sobolewski, Piotr; Walecka, Irena; Dopytalska, Klaudia
2017-01-01
Nail psoriasis is considered a significant psychological and social problem causing functional impairment in affected patients. Nail changes hamper their daily and occupational activities and contribute to a worse quality of life. Almost 50% of patients with psoriasis vulgaris and up to 80% of patients with psoriatic arthritis are afflicted with nail lesions. The important correlation between psoriatic arthritis and nail changes is well established - the presence of the latter is a strong predictor of the development of arthritis. There is a broad spectrum of nail dystrophies associated with psoriasis, ranging from the common pitting, subungual hyperkeratosis and loosening of the nail plate to less frequent discolouration and splinter haemorrhages. Some of these symptoms are also observed in other nail diseases, and further diagnostics should be performed. The assessment tools NAPSI (Nail Psoriasis Severity Index), mNAPSI (Modified Nail Psoriasis Severity Index), and PNSS (Psoriasis Nail Severity Score) are most commonly used to grade the severity of nail involvement in psoriasis and enable the evaluation of therapy effectiveness. The treatment of nail psoriasis is a major clinical challenge. It should be adjusted to the extent of dermal, articular and ungual lesions. Systemic therapies of psoriasis, especially biological agents, are most likely to be effective in treating nail psoriasis. However, as their use is limited in scope and safety, topical therapy remains a mainstay, and the combination of corticosteroids and vitamin D3 analogues is considered to be most helpful.
Respiratory problems in advanced cancer.
Ripamonti, Carla; Fusco, Flavio
2002-04-01
Respiratory problems are an important issue in the palliative care setting, not only from a diagnostic and therapeutic point of view but also from emotion-related aspects involving both the patients and their families and also caregivers. In this paper we consider some of the most common respiratory problems, such as dyspnea, infections, hemoptysis, hiccup. A review of the literature was performed with reference to the frequency, diagnosis and management of the above respiratory problems in patients in advanced and terminal stages of the disease. Particular emphasis was given to the importance of communication with the patients and their families, which is considered a crucial point in the care and the cure of such patients.
Image processing: some challenging problems.
Huang, T S; Aizawa, K
1993-01-01
Image processing can be broadly defined as the manipulation of signals which are inherently multidimensional. The most common such signals are photographs and video sequences. The goals of processing or manipulation can be (i) compression for storage or transmission; (ii) enhancement or restoration; (iii) analysis, recognition, and understanding; or (iv) visualization for human observers. The use of image processing techniques has become almost ubiquitous; they find applications in such diverse areas as astronomy, archaeology, medicine, video communication, and electronic games. Nonetheless, many important problems in image processing remain unsolved. It is the goal of this paper to discuss some of these challenging problems. In Section I, we mention a number of outstanding problems. Then, in the remainder of this paper, we concentrate on one of them: very-low-bit-rate video compression. This is chosen because it involves almost all aspects of image processing. PMID:8234312
Image Processing: Some Challenging Problems
NASA Astrophysics Data System (ADS)
Huang, T. S.; Aizawa, K.
1993-11-01
Image processing can be broadly defined as the manipulation of signals which are inherently multidimensional. The most common such signals are photographs and video sequences. The goals of processing or manipulation can be (i) compression for storage or transmission; (ii) enhancement or restoration; (iii) analysis, recognition, and understanding; or (iv) visualization for human observers. The use of image processing techniques has become almost ubiquitous; they find applications in such diverse areas as astronomy, archaeology, medicine, video communication, and electronic games. Nonetheless, many important problems in image processing remain unsolved. It is the goal of this paper to discuss some of these challenging problems. In Section I, we mention a number of outstanding problems. Then, in the remainder of this paper, we concentrate on one of them: very-low-bit-rate video compression. This is chosen because it involves almost all aspects of image processing.
ERIC Educational Resources Information Center
Clariana, Roy B.; Engelmann, Tanja; Yu, Wu
2013-01-01
Problem solving likely involves at least two broad stages, problem space representation and then problem solution (Newell and Simon, Human problem solving, 1972). The metric centrality that Freeman ("Social Networks" 1:215-239, 1978) implemented in social network analysis is offered here as a potential measure of both. This development research…
[Nail involvement in leprosy].
Belinchón Romero, I; Ramos Rincón, J M; Reyes Rabell, F
2012-05-01
Leprosy, a disease caused by Mycobacterium leprae, primarily affects the skin and nerves, but the nails are also involved in as many as 3 out of 4 patients .The factors that trigger nail changes in leprosy are numerous and include repeated trauma, neuropathy, vascular impairment, infections, lepra reactions, and the drugs used to manage the disease. The changes most often reported include subungual hematomas, onycholysis, onychauxis, onychogryphosis, pterygium unguis, and onychoheterotopia, most of which can be attributed to nerve damage and trauma. Furthermore, the acro-osteolysis that occurs in the advanced stages of the disease may present with brachyonychia, racquet nails, or even anonychia. Infections of the nail bed leading to paronychia and onychomycosis should also be taken into account in leprosy. Other typical changes include longitudinal striae, pitting, macrolunula, Terry nails, leukonychia, hapalonychia, and Beau lines. In this review, we describe the principal nail changes associated with leprosy. These changes, which are highly varied and diverse in origin, are in fact a reflection of the significant morbidity caused by M. leprae infection. Copyright © 2011 Elsevier España, S.L. and AEDV. All rights reserved.
Microstructural lines involving luminescence
NASA Astrophysics Data System (ADS)
Shimada, Kazuhiko
2004-06-01
Japanese National Printing Bureau has been focused upon the development of anti-copy lines for many years. The basic concept with regard to security measure lies in the merge of art and technology. On this basis, our originally developed anti-copy lines show flexibility to various security designs. Our newest anti-copy lines comprising from the Tri-Branched and Divided Lines shows clearer latent image effect compared to that of our other developed anti-copy lines. However, the anti-copy effect of security printing lines with microstructure is deteriorating due to the emergence of digital image techniques with higher resolution. In this situation, this paper introduces a new security measure comprising from luminescence and security printing lines with microstructure. It gives rise to a latent image effect under UV light due to the characteristic microstructure while visually same density. The principle advantage is that the combination of the anti-copy and luminescent feature strongly enhances its secure effect in documents. There is no necessity of two kinds of inks and any specially designed equipment to produce security documents with microstructural lines involving luminescence.
Quantum Algorithm for Linear Programming Problems
NASA Astrophysics Data System (ADS)
Joag, Pramod; Mehendale, Dhananjay
The quantum algorithm (PRL 103, 150502, 2009) solves a system of linear equations with exponential speedup over existing classical algorithms. We show that the above algorithm can be readily adopted in the iterative algorithms for solving linear programming (LP) problems. The first iterative algorithm that we suggest for LP problem follows from duality theory. It consists of finding nonnegative solution of the equation forduality condition; forconstraints imposed by the given primal problem and for constraints imposed by its corresponding dual problem. This problem is called the problem of nonnegative least squares, or simply the NNLS problem. We use a well known method for solving the problem of NNLS due to Lawson and Hanson. This algorithm essentially consists of solving in each iterative step a new system of linear equations . The other iterative algorithms that can be used are those based on interior point methods. The same technique can be adopted for solving network flow problems as these problems can be readily formulated as LP problems. The suggested quantum algorithm cansolveLP problems and Network Flow problems of very large size involving millions of variables.
Food production -- problems and prospects.
Anifowoshe, T O
1990-03-01
Improvements are needed in balancing the problems associated with population growth and food production. A review of the problems of rapid population growth and declining food production and suggestions for resolution are given. World population has increased over the past 10 years by 760 million, which is equal to adding the combined population of Africa and South America. Future increases are expected to bring total population to 6.1 billion by the year 2000 and 8.2 billion in 2025 (exponential increases). Food production/capita has declined since 1971 in the world and in Nigeria, particularly in the recent past. The food production problem is technical, environmental, social, political, and economic. Various scientific and technological methods for increasing food production are identified: mechanization, irrigation, use of fertilizers, control of weeds and insects, new varieties of farm animals or high-yielding strains of grain, land reclamation, soil conservation, river basin development, adequate storage facilities, infrastructure development, and birth control. Economic and social approaches involve short-term and long-term strategies in social readjustment and institutional change. For instance, large scale farmers should become contract growers for certain firms. Bureaucratic red tape should be eliminated in institutions which provide agricultural services. Environmental problems need urgent attention. Some of these problems are soil erosion from mechanization, water salinization from irrigation, accumulation of DDT in food and water and animal life from pesticide use, and water pollution from chemical fertilizers. Food production can be increased with more ecologically sound practices. Information about weather and weather forecasting allows for more suitable land management. The influence of rainfall (the amount and distribution) in Nigeria is greater than any other climatic factor. Solar radiation is a significant feature in production of dry matter and
Rütsche, Bruno; Hauser, Tobias U; Jäncke, Lutz; Grabner, Roland H
2015-01-01
The problem size effect is a well-established finding in arithmetic problem solving and is characterized by worse performance in problems with larger compared to smaller operand size. Solving small and large arithmetic problems has also been shown to involve different cognitive processes and distinct electroencephalography (EEG) oscillations over the left posterior parietal cortex (LPPC). In this study, we aimed to provide further evidence for these dissociations by using transcranial direct current stimulation (tDCS). Participants underwent anodal (30min, 1.5 mA, LPPC) and sham tDCS. After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems. We found that the tDCS effects on performance and oscillatory activity critically depended on the problem size. While anodal tDCS improved response latencies in large arithmetic problems, it decreased solution rates in small arithmetic problems. Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased. These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.
Problem? "No Problem!" Solving Technical Contradictions
ERIC Educational Resources Information Center
Kutz, K. Scott; Stefan, Victor
2007-01-01
TRIZ (pronounced TREES), the Russian acronym for the theory of inventive problem solving, enables a person to focus his attention on finding genuine, potential solutions in contrast to searching for ideas that "may" work through a happenstance way. It is a patent database-backed methodology that helps to reduce time spent on the problem,…
Problem? "No Problem!" Solving Technical Contradictions
ERIC Educational Resources Information Center
Kutz, K. Scott; Stefan, Victor
2007-01-01
TRIZ (pronounced TREES), the Russian acronym for the theory of inventive problem solving, enables a person to focus his attention on finding genuine, potential solutions in contrast to searching for ideas that "may" work through a happenstance way. It is a patent database-backed methodology that helps to reduce time spent on the problem,…
Applying Employee Involvement in Schools.
ERIC Educational Resources Information Center
Mohrman, Susan Albers; And Others
1992-01-01
The applicability of employee-involvement approaches to the management of schools is explored, describing three approaches (parallel-suggestion involvement, job involvement, and high involvement). Design issues (technology; organizational structure; leadership; organizational boundaries, customer definition, and relation to stakeholder; measures;…
Multidrug toxicity involving sumatriptan.
Knittel, Jessica L; Vorce, Shawn P; Levine, Barry; Hughes, Rhome L; Bosy, Thomas Z
2015-01-01
A multidrug fatality involving sumatriptan is reported. Sumatriptan is a tryptamine derivative that acts at 5-HT(1B/1D) receptors and is used for the treatment of migraines. The decedent was a 21-year-old white female found dead in bed by her spouse. No signs of physical trauma were observed and a large number of prescription medications were discovered at the scene. Toxicological analysis of the central blood revealed sumatriptan at a concentration of 1.03 mg/L. Following therapeutic dosing guidelines, sumatriptan concentrations do not exceed 0.095 mg/L. Sumatriptan was isolated by solid-phase extraction and analyzed using liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode. A tissue distribution study was completed with the following concentrations measured: 0.61 mg/L in femoral blood, 0.56 mg/L in iliac blood, 5.01 mg/L in urine, 0.51 mg/kg in liver, 3.66 mg/kg in kidney, 0.09 mg/kg in heart, 0.32 mg/kg in spleen, 0.01 mg/kg in brain, 15.99 mg/kg in lung and 78.54 mg/45 mL in the stomach contents. Carisoprodol, meprobamate, fluoxetine, doxylamine, orphenadrine, dextromethorphan and hydroxyzine were also present in the blood at the following concentrations: 3.35, 2.36, 0.63, 0.19, 0.06, 0.55 and 0.16 mg/L. The medical examiner ruled the cause of death as acute mixed drug toxicity and the manner of death as accident.
Cheryl A. Smith
2008-01-01
Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...
Quadratic eigenvalue problems.
Walsh, Timothy Francis; Day, David Minot
2007-04-01
In this report we will describe some nonlinear eigenvalue problems that arise in the areas of solid mechanics, acoustics, and coupled structural acoustics. We will focus mostly on quadratic eigenvalue problems, which are a special case of nonlinear eigenvalue problems. Algorithms for solving the quadratic eigenvalue problem will be presented, along with some example calculations.
ERIC Educational Resources Information Center
WALLS, FOREST
PRESENT MIGRANT LABOR PROBLEMS AND SOLUTIONS WHICH HAVE BEEN PROPOSED ARE PRESENTED. THE FIRST PROBLEM AREA IS PROVIDING EDUCATION FOR MIGRANT CHILDREN. THIS IS HINDERED BY THE PROBLEM OF SECURING COMPLIANCE WITH MINIMUM EDUCATION LAWS AND BY LAWS PROHIBITING EMPLOYMENT OF CHILDREN DURING SCHOOL HOURS. A SECOND PROBLEM AREA IS THAT OF CHILD LABOR.…
2017-01-02
papers. Our problem bears some resemblance to the ATFM problem in that routing decisions are somewhat similar to the scheduling decisions (what sequence...Problem (2) bears strong resemblance to problem (1); compare, for example, con- straint (2m) to constraint (1n). Despite this resemblance, the two problems...2000. D. Bertsimas, D. B. Brown , and C. Caramanis. Theory and applications of robust optimiza- tion. SIAM Review, 53(3):464–501, 2011a. D. Bertsimas
The Challenge of Problem Residents
Yao, David C; Wright, Scott M
2001-01-01
Internal medicine residency training is demanding and residents can experience a wide variety of professional and personal difficulties. Residency programs everywhere have had and will continue to have problem residents. Training programs should be equipped to effectively identify and manage residents who experience problems. Previous articles that have been published on the topic of problem residents primarily addressed concerns such as impairment due to depression and substance abuse. The content of this article is derived from a comprehensive review of the literature as well as other data sources such as interviews with program directors and workshops at national professional meetings. This article focuses primarily on four issues related to problem residents: their identification, underlying causes, management, and prevention. The study attempts to be evidence-based, wherever possible, highlighting what is known. Recommendations based on the synthesis of the data are also made. Future ongoing studies of problem residents will improve our understanding of the matters involved, and may ultimately lead to improved outcomes for these trainees. PMID:11520388
Getting Fathers Involved in Child-Related Therapy
ERIC Educational Resources Information Center
Phares, Vicky; Fields, Sherecce; Binitie, Idia
2006-01-01
Fathers are involved in treatment for child and family problems to a far lesser extent than are mothers. This article reviews the level of fathers' inclusion in therapy, delineates possible barriers to fathers' participation in child-related treatment, and discusses factors associated with fathers' involvement in therapy. Empirically and…
Outdoor Education Directory: Organizations Involved in Outdoor Experiential Education.
ERIC Educational Resources Information Center
ERIC Clearinghouse on Rural Education and Small Schools, Charleston, WV.
This directory lists organizations actively involved in outdoor experiential education. Outdoor experiential education includes some or all of the following elements: (1) active involvement in solving outdoor problems; (2) verbal reflection following the experience; (3) introduction of a level of stress or challenge in completing the outdoor…
Ethical issues involving the internet
Scott, T.J.; Kallman, E.A.; Lelewer, D.
1994-12-31
During the 90`s, the {open_quotes}Information Superhighway{close_quotes} has received widespread publicity. Many campuses have participated in this drive to an information based society by becoming participating nodes on the Internet. As an information provider, the Internet has the potential to change the college experience in many ways, both good and bad. It also poses a number of problems for college students in areas such as privacy, access, and honesty. It provides professors with a dynamic information storage and retrieval tool that offers the opportunity to modernize both curriculum experiences and pedagogical approaches. On some campuses, Internet access and capability has become so important that course modules and whole courses are being built. The panelists will each discuss a different issue involved with making the Internet more integral to the collegiate environment. The first panelist will consider risks and threats that an institution of higher learning must consider as it approaches Internet use will be presented. The steps an institution took to build policies and deal with {open_quotes}inevitable incidents{close_quotes} that will occur as the Internet is opened to full use by both students and faculty. The second panelist will present four computer ethics Each module uses the abundance and dynamism of Internet information to provide challenging {open_quotes}Ethics in the Computer Workplace{close_quotes} experiences that could not easily be done by traditional means. The third panelist will discuss a course module that explores both the positive and negative potential of the Internet. The costs and ease of Internet access, as well as normally available Internet tools, are also presented. This module has been used in a course called {open_quotes}Ethical and Social Issues in Computer Science{close_quotes} and will be used in a general-education course to be offered beginning in 1994-95.
Emerging pathomechanisms involved in obesity.
D'Aniello, Roberta; Troisi, Jacopo; D'Amico, Osvaldo; Sangermano, Maria; Massa, Grazia; Moccaldo, Anna; Pierri, Luca; Poeta, Marco; Vajro, Pietro
2015-01-01
Overweight/obesity prevalence has increased dramatically worldwide. Recent evidence suggests sleep deprivation/fragmentation, fructose-exceedingly rich diets, and exposure to endocrine disruptors (eg, bisphenol A, BPA) as emerging additional factors involved in pathomechanisms and in the treatment resistance of obesity and its complications. Our study focuses on these factors for further preventive/therapeutic approaches in paediatric obesity. Fifty-four Italian children (cases: n = 31 overweight/obese; controls: n = 23 normal weight) were clinically/anthropometrically characterised. Parents completed questionnaires on the relation between obesogenic factors and childhood obesity. BPA was measured by gas chromatography/tandem mass spectrometry on early morning urine samples. Correlations between the continuous variables were analysed using Spearman rank correlation. Sleep deprivation/fragmentation, nocturnal breathing problems, and daytime sleepiness increased with increasing body mass index, correlating with the presence of clinical markers of metabolic syndrome (eg, acanthosis nigricans). Frequency of sugar-enriched drink consumption and the amount of fructose per portion and/or per week increased, paralleling the ponderal excess and all the other anthropometric parameters. In the entire sample population, free and total BPA levels increased paralleling the body mass index increase (r > 0.8), whereas the conjugate demonstrated the opposite trend. The re-use of disposable plastic showed a positive correlation with urinary BPA levels. Despite its exploratory nature, the results of our pilot study confirm the close relation between certain factors and paediatric obesity, underscoring their role as emerging targets for prevention and therapy.
Pérez, Diana I
2005-01-01
In this paper I present, in the first place, two of the main problems in the philosophy of mind: 1) the problem of the criteria of the mental, and 2) the problem of the relationship between the mental and the physical. In the last part, I mention two problems highly discussed nowadays which, in my view, will produce the most important advance in the knowledge of our minds in the next decades: the problem of consciousness and its neural basis, and the problem of the origin and development of a theory of mind.
The Algorithm Selection Problem
NASA Technical Reports Server (NTRS)
Minton, Steve; Allen, John; Deiss, Ron (Technical Monitor)
1994-01-01
Work on NP-hard problems has shown that many instances of these theoretically computationally difficult problems are quite easy. The field has also shown that choosing the right algorithm for the problem can have a profound effect on the time needed to find a solution. However, to date there has been little work showing how to select the right algorithm for solving any particular problem. The paper refers to this as the algorithm selection problem. It describes some of the aspects that make this problem difficult, as well as proposes a technique for addressing it.
Nail involvement in pemphigus vulgaris.
Engineer, L; Norton, L A; Ahmed, A R
2000-09-01
Nail involvement in pemphigus vulgaris is relatively rare. We describe a case of severe pemphigus involving both the skin and oral mucosa in which an acute exacerbation was preceded by the onset of nail involvement of all 4 extremities. Nail involvement occurred in the form of hemorrhagic paronychia of multiple digits. Oral, cutaneous, and nail manifestations of the disease were all well controlled by systemic therapy. A review of the literature on nail involvement in pemphigus reveals that this involvement may be manifested in multiple ways, with chronic paronychia and onychomadesis being the most common. Involvement of the nail occurs most frequently either as part of the initial presentation, or just before or concurrent with a flare of pre-existing disease. Nail involvement, when it occurs, is usually present when the disease is severe. Topical therapy is insufficient, and systemic therapy is warranted. In the majority of cases, nail recovery is complete, with no residual damage.
Parent Involvement in the Schools
ERIC Educational Resources Information Center
Anselmo, Sandra
1977-01-01
Educators at all levels of the American educational system have become increasingly interested in involving parents in the work of the schools but need more guidance in making some crucial administrative decisions prior to such involvement. (Author)
User involvement and the NHS reforms.
Rhodes, Penny; Nocon, Andrew
1998-11-01
The policy of 'user involvement' in the UK National Health Service emerged during the 1990s along with the reforms that created an internal market. Despite the official rhetoric, progress has been limited. Critics suggest that, not only was the policy flawed in its conception by the construction of service users as consumers and the conflation of consumerism with empowerment, but collaborative models of involvement have tended to legitimate rather than challenge existing provision. Some commentators have questioned the value of user involvement initiatives and proposed that alternative approaches, such as a strengthening of procedural rights or alignment with broader political campaigns, would be more appropriate. The low prominence given in the recent Government White Paper The New NHS1 to the contribution of service users, however, represents less of an ideological shift than a concentration on other, in the Government's view, more pressing priorities: namely, a concern to address the problems of public legitimacy and low staff morale by engaging in greater public participation and giving health professionals a more central role. The result has been a weakening of the users' voice by a conflation of user involvement with public participation and giving health professionals the authority to define users' needs for them. Service users risk, not only having their contribution devalued, but losing the right to an independent and distinctive voice. There is a real danger that the issues of user involvement will not be included on local agendas and the disparities between provision and need and between professionals' and users' views will increase.
IT Problem Management â process responsible for managing Lifecycle of all IT problems. The primary objective is to prevent incidents from occurring and to minimize impact of incidents that cannot...
... Ask you about your relationships, current sexual practices, attitude towards sex, other medical problems you might have, ... You and your partner may be referred for counseling to help with relationship problems or to work ...
Sleep problems are a common side effect during cancer treatment. Find out how a polysomnogram can assess sleep problems. Learn about the benefits of managing sleep disorders in men and women with cancer.
... Read MoreDepression in Children and TeensRead MoreBMI Calculator Menstrual Cycle ProblemsFrom missed periods to painful periods, menstrual cycle problems are common, but usually not serious. Follow ...
ERIC Educational Resources Information Center
Eperson, D. B.
1991-01-01
This section includes eight problems to which the journal invites readers to respond. Problem topics include angles in alternate segments, pentominoes, a new triangle of numbers, cricket scores, symmetrical pentagons, inequalities, a pythagorean dissection, and magic squares. (MDH)
ERIC Educational Resources Information Center
Eperson, D. B.
1991-01-01
This section includes eight problems to which the journal invites readers to respond. Problem topics include angles in alternate segments, pentominoes, a new triangle of numbers, cricket scores, symmetrical pentagons, inequalities, a pythagorean dissection, and magic squares. (MDH)
Musculoskeletal problems in Parkinson's disease: neglected issues.
Kim, Young Eun; Lee, Woong-Woo; Yun, Ji Young; Yang, Hui June; Kim, Han-Joon; Jeon, Beom S
2013-07-01
To identify the prevalence and clinical features of musculoskeletal problems in patients with Parkinson disease (PD) compared to controls. 400 PD patients and 138 age- and sex-matched controls were interviewed by physicians about their musculoskeletal problems. The prevalence of musculoskeletal problems was significantly higher in the PD group than in the control group (66.3% vs. 45.7%, P < 0.001). Commonly involved body sites were the low back, knee, and shoulder in that order. The low back was more frequently involved in the PD group than in the control group (44.3% vs. 24.6%, P < 0.001), and the shoulder tended to be more involved in the PD group than in the control group (15.0% vs. 8.7%, P = 0.061). However, the knee was similarly involved in both group (12.3% vs. 18.0%, P = 0.121). Among the past diagnoses associated with musculoskeletal problems, frozen shoulder, low back pain, osteoporosis and fracture were more common in the PD group than in the control group (P < 0.05). Older age, female, and a higher score on the Unified Parkinson's Disease Rating Scale I & II were associated with musculoskeletal problems in the PD group. Only 26.8% of the PD patients and 52.5% of the controls with musculoskeletal problems answered that their musculoskeletal problems were recovering. Furthermore, musculoskeletal problems in the PD group tended to receive less treatment than that of the control group (P = 0.052). Musculoskeletal problems were more common in the PD group than in the controls. Furthermore, despite PD patients having a higher prevalence, they did not receive adequate treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.
Families Get Involved! Learning Partners.
ERIC Educational Resources Information Center
Office of Educational Research and Improvement (ED), Washington, DC. Media and Information Services.
Noting that families who are involved in their children's education make a difference in their child's performance, this two-page information sheet encourages families to get involved by listing the benefits of family involvement on one side and the ways adult family members can help in the school on the other. As a result of family participation:…
Parental Involvement in High Schools.
ERIC Educational Resources Information Center
Brian, Donna JG
Although parental involvement is recommended at all levels of schooling, involvement of parents at the secondary level has not been well defined in the literature. This paper presents findings of a case study that examined three high schools with varying levels of parental involvement--the first, a large high school with a predominantly working…
Measuring Involvement with Social Issues.
ERIC Educational Resources Information Center
Nowak, Glen J.; Salmon, Charles T.
A study applied research concepts from consumer product involvement to test a model for research on involvement with social issues. Issue involvement was defined as the state or level of perceived importance and/or interest evoked by a stimulus (issue) within a specific situation. Attitudes on four social issues--abortion, pornography, the…
Measuring Parent Involvement Program Implementation.
ERIC Educational Resources Information Center
Abramson, Lisa S.
1994-01-01
Investigates implementation of the 1990-91 New York City Parent Involvement Program. The first section summarizes the research underlying development of methodology for measuring parent involvement program implementation across diverse program sites. The second section outlines a six-step data collection and measurement methodology involving site…
The molecular matching problem
NASA Technical Reports Server (NTRS)
Kincaid, Rex K.
1993-01-01
Molecular chemistry contains many difficult optimization problems that have begun to attract the attention of optimizers in the Operations Research community. Problems including protein folding, molecular conformation, molecular similarity, and molecular matching have been addressed. Minimum energy conformations for simple molecular structures such as water clusters, Lennard-Jones microclusters, and short polypeptides have dominated the literature to date. However, a variety of interesting problems exist and we focus here on a molecular structure matching (MSM) problem.
The three tiers of screening for sarcoidosis organ involvement.
Judson, Marc A
2016-04-01
Sarcoidosis may involve any organ in the body. Organ involvement with sarcoidosis may go undetected. This manuscript addresses a suggested approach to screening for sarcoidosis organ involvement. As sarcoidosis organ involvement may never cause symptoms or clinical problems, it is not always necessary to expend the time or expense to detect all organs involved with sarcoidosis. On the other hand, some forms of sarcoidosis organ involvement may have potentially severe consequences such as permanent vision impairment from eye sarcoidosis and sudden death from cardiac sarcoidosis. We believe it useful to describe three tiers of screening for sarcoidosis organ involvement. The first tier of screening involves eliciting a medical history and performing a physical examination. This is a useful screen for all organs. The second tier of screening involves performing specific laboratory tests to search for specific sarcoidosis organ involvement, even if there is no clinical sign or symptom to suggest involvement of that organ. Such screening is only recommended for a limited number of specific organs. The third tier of screening is complex and involves the performance of multiple tests/algorithms or examinations by subspecialists to search for specific organ involvement. The third tier of screening is used to evaluate eye sarcoidosis, vitamin D dysregulation associated with sarcoidosis, and cardiac sarcoidosis. It is hoped that this approach to screening for sarcoidosis organ involvement will be a springboard for rigorous examination of this process that is likely to benefit sarcoidosis patients. Copyright © 2016 Elsevier Ltd. All rights reserved.
A multistage linear array assignment problem
NASA Technical Reports Server (NTRS)
Nicol, David M.; Shier, D. R.; Kincaid, R. K.; Richards, D. S.
1988-01-01
The implementation of certain algorithms on parallel processing computing architectures can involve partitioning contiguous elements into a fixed number of groups, each of which is to be handled by a single processor. It is desired to find an assignment of elements to processors that minimizes the sum of the maximum workloads experienced at each stage. This problem can be viewed as a multi-objective network optimization problem. Polynomially-bounded algorithms are developed for the case of two stages, whereas the associated decision problem (for an arbitrary number of stages) is shown to be NP-complete. Heuristic procedures are therefore proposed and analyzed for the general problem. Computational experience with one of the exact problems, incorporating certain pruning rules, is presented with one of the exact problems. Empirical results also demonstrate that one of the heuristic procedures is especially effective in practice.
ERIC Educational Resources Information Center
Linton, Marigold
Previous approaches to the learning problems of American Indian children are viewed as inadequate. An alternative is suggested which emphasizes the problem solution strategies which these children bring to the school situation. Solutions were analyzed in terms of: (1) their probability; (2) their efficiency at permitting a present problem to be…
Exploratory Problems in Mathematics.
ERIC Educational Resources Information Center
Stevenson, Frederick W.
This book attempts to introduce students to the creative aspects of mathematics through exploratory problems. The introduction presents the criteria for the selection of the problems in the book. Criteria indicate that problems should: be immediately attractive, require data to be generated or gathered, appeal to students from junior high school…
Techniques of Problem Solving.
ERIC Educational Resources Information Center
Krantz, Steven G.
The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…
Problems for Computer Mathematics.
ERIC Educational Resources Information Center
Allison, Ronald; And Others
This booklet contains some 80 problems in mathematics suitable for computer solution. The problems range from very simple to complex. Problems have been included from most mathematic disciplines, including number theory, analytical geometry, probability and statistics, trigonometry, equations, and sequence and limits. For the most part these…
ERIC Educational Resources Information Center
King, James C.
1988-01-01
This pamphlet discusses group problem solving in schools. Its point of departure is that teachers go at problems from a number of different directions and that principals need to capitalize on those differences and bring a whole range of skills and perceptions to the problem-solving process. Rather than trying to get everyone to think alike,…
Techniques of Problem Solving.
ERIC Educational Resources Information Center
Krantz, Steven G.
The purpose of this book is to teach the basic principles of problem solving in both mathematical and non-mathematical problems. The major components of the book consist of learning to translate verbal discussion into analytical data, learning problem solving methods for attacking collections of analytical questions or data, and building a…
ERIC Educational Resources Information Center
Capobianco, Brenda M.; Tyrie, Nancy
2009-01-01
In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…
ERIC Educational Resources Information Center
Capobianco, Brenda M.; Tyrie, Nancy
2009-01-01
In a unique school-university partnership, methods students collaborated with fifth graders to use the engineering design process to build their problem-solving skills. By placing the problem in the context of a client having particular needs, the problem took on a real-world appeal that students found intriguing and inviting. In this article, the…
Exploratory Problems in Mathematics.
ERIC Educational Resources Information Center
Stevenson, Frederick W.
This book attempts to introduce students to the creative aspects of mathematics through exploratory problems. The introduction presents the criteria for the selection of the problems in the book. Criteria indicate that problems should: be immediately attractive, require data to be generated or gathered, appeal to students from junior high school…
Problem Solving. Research Brief
ERIC Educational Resources Information Center
Muir, Mike
2004-01-01
No longer solely the domain of Mathematics, problem solving permeates every area of today's curricula. Ideally students are applying heuristics strategies in varied contexts and novel situations in every subject taught. The ability to solve problems is a basic life skill and is essential to understanding technical subjects. Problem-solving is a…
Teaching Textbook Story Problems.
ERIC Educational Resources Information Center
LeBlanc, John F.
1982-01-01
Teaching story problems is seen to offer opportunities for developing the problem-solving process. Four steps described by George Polya are interpreted for the classroom as: (1) Tell, (2) Show, (3) Solve, and (4) Check. The teacher's role is detailed and the process is viewed to work for all problem types. (MP)
Assessment Problems in Reading.
ERIC Educational Resources Information Center
MacGinitie, Walter H., Ed.
The papers in this volume deal with a range of assessment problems in reading. The first paper, by Karlin, introduces the general problem of using assessment procedures to guide teaching. The next six papers deal with various aspects of this general problem. Otto discusses the distinction between norm-referenced, standardized achievement tests and…
Rocks in a Box: A Three-Point Problem.
ERIC Educational Resources Information Center
Leyden, Michael B.
1981-01-01
Describes a simulation drilling core activity involving the use of a physical model from which students gather data and solve a three-point problem to determine the strike and dip of a buried stratum. Includes descriptions of model making, data plots, and additional problems involving strike and dip. (DS)
A Cognitive Model for Problem Solving in Computer Science
ERIC Educational Resources Information Center
Parham, Jennifer R.
2009-01-01
According to industry representatives, computer science education needs to emphasize the processes involved in solving computing problems rather than their solutions. Most of the current assessment tools used by universities and computer science departments analyze student answers to problems rather than investigating the processes involved in…
Occupational Health Problems of Musicians
Chong, John; Lynden, Melody; Harvey, David; Peebles, Marie
1989-01-01
Musicians, as well as other performing artists, may have their careers interrupted by, interfered with, or terminated by occupational health problems involving the neuro-musculoskeletal system. Adverse working conditions, organization, and activity may affect the health of musicians in all age groups and at all levels of performing ability. Instrument-specific health problems are related to excessive force, static loading, repetitive movement, and duration of musical performance. Important risk factors are 1) change in technique or instrument; 2) intense preparation for a performance; 3) preparation of a new and difficult repertoire; and 4) prolonged periods of performance without rest. Treatment protocols and health promotion or disease prevention programs are being developed in collaboration with the performing arts community. ImagesFigure 1Figure 2Figure 3 PMID:21248930
Problems of nonlinear deformation
NASA Astrophysics Data System (ADS)
Grigoliuk, E. I.; Shalashilin, V. I.
A method of continuing the solution is discussed with respect to a parameter for a certain class of nonlinear problems in solid mechanics. Modifications of the method are developed in order to implement a unified continuation process at regular and limit points in the set of solutions, with extensions to nonlinear boundary value problems. Algorithms are developed for solving large deflection problems of elastic arches and large axisymmetric deflection problems for shells of revolution. In particular, the algorithms are used for the analysis of large deflections of circular arches and toroidal shells. Examples of natural vibration and stability problems for parallelograms and trapezoidal membranes and panels are given.
Example Problems in LES Combustion
2016-09-26
96W-2016-0160 13. SUPPLEMENTARY NOTES 14. ABSTRACT This memorandum provides a brief introduction to finite rate chemistry in the framework of...4 2.2 The Closure Problem for Turbulent Chemistry ……………………………………..7 2.3 Initializing the Turbulent Field……………………………………………………...9 3.0...milliseconds…..……26 1 Distribution A 1.0 INTRODUCTION This memorandum addresses issues involving gas-phase finite rate chemistry and droplet
Health and problem behavior among people with intellectual disabilities.
May, Michael E; Kennedy, Craig H
2010-01-01
Good health significantly improves a person's quality of life. However, people with intellectual disabilities disproportionately have more health problems than the general population. Further complicating the matter is that people with more severe disabilities often cannot verbalize health complications they are experiencing, which leads to health problems being undiagnosed and untreated. It is plausible these conditions can interact with reinforcement contingencies to maintain problem behavior because of the increased incidence of health problems among people with intellectual disabilities. This paper reviews common health problems influencing problem behavior and reinforcement processes. A clear implication of this review is the need for comprehensive functional assessments of problem behavior involving behavior analysts and health professionals.
Problems in Geometrical Optics
ERIC Educational Resources Information Center
Joyce, L. S.
1973-01-01
Ten laboratory exercises on optics are described to clarify concepts involving point objects and converging lenses producing real images. Mathematical treatment is kept to a minimum to stress concepts involved. (PS)
Problems in Geometrical Optics
ERIC Educational Resources Information Center
Joyce, L. S.
1973-01-01
Ten laboratory exercises on optics are described to clarify concepts involving point objects and converging lenses producing real images. Mathematical treatment is kept to a minimum to stress concepts involved. (PS)
Anal involvement in pemphigus vularis.
Khezri, Somayeh; Mahmoudi, Hamid-Reza; Masoom, Seyedeh Nina; Daneshpazhooh, Maryam; Balighi, Kamran; Hosseini, S Hamed; Chams-Davatchi, Cheyda
2013-01-01
Background. Pemphigus vulgaris (PV) is an autoimmune blistering disease of the skin and mucosa. Anal mucosa may be involved in PV, but the frequency and clinical profile are not fully ascertained. Objective. The aim was to investigate the involvement of the anal area in newly diagnosed PV patients. Patients and Methods. A total of 168 consecutive newly diagnosed PV patients were enrolled. Anal symptoms and signs, involvement of other body sites, and severity of disease were recorded. Results. A total of 47 out of 168 patients (27.9%) had involvement of the anal area. Anal involvement was significantly associated with PV lesions in ophthalmic (P = 0.03), nasal (P = 0.02), and genital mucosa (P < 0.001) but not the oral cavity (P = 0.24). There was a significant association between number of involved mucosal sites and anal involvement (P < 0.001). Anal involvement was associated with oral severity (P = 0.02). Constipation was the most frequent symptom (73.8%) followed by pain on defecation (50%). Seventeen patients (36%) were symptom-free. Erosion was the most frequent sign (91.5%). Conclusion. Anal involvement in PV seems to be more frequent than previously assumed. Routine anal examination is recommended even in asymptomatic patients as anal involvement appears to correlate with the severity of PV.
Sacroiliac joint involvement in psoriasis.
Kaçar, Cahit; Sezer, Ilhan; Kocabaş, Hilal; Cay, Hasan Fatih; Cevikol, Can; Alpsoy, Erkan; Melikoğlu, Meltem Alkan; Akman, Ayşe
2010-07-01
Psoriasis is a skin disorder that is associated with arthritis. Sacroiliac joint involvement is considered to be less frequent than the other types of psoriatic arthritis. Additionally, the psoriatic sacroiliitis is considered to be asymmetric in general. We aimed to define the frequency and type of sacroiliac involvement in patients with psoriasis. Patients with psoriasis were included the study. Characteristics of skin, nail and articular involvement were noted. Psoriasis area and severity index was calculated. Antero-posterior pelvic X-rays were obtained and graded by two rheumatologists and a radiologist independently. One hundred and thirty-three patients were included. Thirty-seven of patients (27%) have articular involvement symptomatically. The sacroiliac joint involvement was observed in 34 (26%) of patients. More than one-half of sacroiliac involvement was bilateral while less than one-half was in symptomatic patients regarding sacroiliitis. Fifty-seven percentages of all patients have psoriatic nail involvement. Sacroiliac joint involvement did not show any significant association with psoriatic nail involvement or the severity of skin disease. We found higher frequency of sacroiliac joint involvement and bilateral sacroiliitis in patients with psoriasis. This is in contrast to present information about the association of psoriasis and sacroiliitis. These findings need confirmation by further studies and with more sophisticated techniques such as magnetic resonance imaging.
Linear stochastic optimal control and estimation problem
NASA Technical Reports Server (NTRS)
Geyser, L. C.; Lehtinen, F. K. B.
1980-01-01
Problem involves design of controls for linear time-invariant system disturbed by white noise. Solution is Kalman filter coupled through set of optimal regulator gains to produce desired control signal. Key to solution is solving matrix Riccati differential equation. LSOCE effectively solves problem for wide range of practical applications. Program is written in FORTRAN IV for batch execution and has been implemented on IBM 360.