bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropy of Dynamic Young's Modulus and Internal Friction in Wood
Authors: Ono Teruaki , Norimoto Misato
Published: September 2006

The dynamic Young's modulus E and the internal friction Q
-1 in three principal directions were measured from the longitudinal vibration in several species of softwood and hardwood. The modulus E in the radial (R) and tangential (T) directions was much lower than that in the longitudinal (L) direction regardless of the wood species, and the order of magnitude was E

l
≫E

r
> E

t
, whereas the friction Q
-1 showed exactly the opposite tendency, i.e., Q

l

-1 ≪Q

r

-1 < Q

t

-1. An investigation of the relationship between the values showed that the internal friction could be expressed by an exponential equation of the specific Young's modulus E/γ regardless of the direction and wood species, and that the exponent in three principal directions was slightly lower than that in the L direction. Furthermore, the differences in the values (E and Q
-1) and exponents between directions were considered from the structural aspect, and it was found that the causes were the same and could be explained well by the difference in the structural factors.
XPS, IR and 13C-NMR Spectra of TaF5-Doped Poly-phenylenesulfide
Authors: Tsukamoto Jun , Matsumura Kiichiro
Published: September 2006

The XPS, IR and 13C-NMR spctra of TaF5-doped poly-phenylenesulfide (PPS) were measured in order to investigate the conductivity mechanism in doped PPS. The result indicate that the double-bond character of the bonds between sulfur atoms and adjacent phenyl rings increases upon doping, which is followed by removal of the electrons from the sulfur atoms. It is suggested that a weak conjugate system is produced by the sulfur atoms in doped PPS.
Two Components of Light-Induced Photoconductivity Decays in a-Si:H
Authors: Kakinuma Hiroaki , Nishikawa Satoshi , Watanabe Tsukasa , Nihei Kohji
Published: September 2006

This paper reports the sample dependence of light-induced photoconductivity σph decays in glow-discharge a-Si:H films. “Device-grade” and lightly-P-doped samples both displayed a fast σph decay component at the beginning of illumination, and a subsequent slow one. “Defective” samples, on the other hand, only showed a slow component. A combined measurement of the σph light intensity dependence γ revealed that the fast component is accompanied by a rapid change in γ. These results are discussed on the basis of a simplified model which assumes two distinct recombination processes, i.e., the process from band to tail and the process through dangling bonds.
Amorphous-Silicon Solar Cells Prepared by a Combined Photochemical-Plasma CVD Technique
Authors: Kenne Jean , Yamada Akira , Konagai Makoto , Takahashi Kiyoshi
Published: September 2006

A new technique for the fabrication of pin amorphous-silicon solar cells in which the p-layer can be deposited by photo-CVD whereas the i- and n-layers are deposited by conventional plasma CVD has been developed. Wide-bandgap, highly-conductive p-type a-SiC:H layers were obtained by direct photochemical vapor deposition from a mixture of disilane and methylsilane or acetylene. On these layers, i- and n-layers consisting of respectively of slightly-boron-doped, and phosphorus-doped amorphous silicon were successively deposited by glow-discharge decomposition in silane to form the pin structure. A considerable improvement of the carrier collection efficiency, especially in the short wavelength region, was observed in cells prepared by the new fabrication method, and a conversion efficiency of 9.46% was obtained.
Effect of Self-Purification and Polarity on Surface Photoconductivity of CdS Crystals
Authors: Sasaki Kazuo
Published: September 2006

It was possible to grow pure CdS crystals, which displayed only the intrinsic photoconduction, by sublimation in which sublimating CdS vapor worked as a trap to remove impurities. CdS crystals without intentionally added impurities thus obtained had a wide range of specific resistivity from 10 to 1013\varOmega cm. Specimens with surfaces parallel to C-plane about 7×5×1 mm3in size were sliced off a single crystal boule having various resistivities, of which dark resistivities, spectral distribution of photocurrent and thermally stimulated current were studied on both (0001) and (0001̄) surface. From the results of the measurement of the thermally stimulated current curves, it was found that shallow electron traps were predominant in (0001̄) surface, whereas deep electron traps were predominant in (0001) surface. In the case of dark resistivity and spectral distribution of photoconductivity, the experimental results are shown as a tendency in which the local segregations were more effective on these properties, compared with the influences of polarity on them.
The Alternating Counting Method for Low-Background Radiation Measurement
Authors: Yamakoshi Kazuo
Published: September 2006

In order to obtain good statistics in low-background radiation measurements a fairly long counting time is necessary. Therefore the experimental accuracy depends tightly on the gain stability of counting system. A standard sample and a test sample are alternately measured for a certain interval, T, and finally the accumulated counts minus background counts for the respective samples are compared. Then it is expected that the effects due to the gain variations having time constants several times larger than T can be cancelled out from the ratio. By using a liquid scintillation counter system it is proved, in the present research, that there are suitable alternation intervals for the required experimental precision and the distributions of the results obtained for these intervals are discussed. In the case of interval T=200 sec. the observed results agree with the expected values in the precision of ±0.15% in a wide range of sample counting rate.
Transmembrane domain histidines contribute to regulation of AE2-mediated anion exchange by pH
Authors: Stewart A. K. , Kurschat C. E. , Burns D. , Banger N. , Vaughan-Jones R. D. , Alper S. L.
Published: September 2006

Activity of the AE2/SLC4A2 anion exchanger is modulated acutely by pH, influencing the transporter's role in regulation of intracellular pH (pHi) and epithelial solute transport. In Xenopus oocytes, heterologous AE2-mediated Cl−/Cl− and Cl−/HCO3− exchange are inhibited by acid pHi or extracellular pH (pHo). We have investigated the importance to pH sensitivity of the eight histidine (His) residues within the AE2 COOH-terminal transmembrane domain (TMD). Wild-type mouse AE2-mediated Cl−/Cl− exchange, measured as DIDS-sensitive 36Cl− efflux from Xenopus oocytes, was experimentally altered by varying pHi at constant pHo or varying pHo. Pretreatment of oocytes with the His modifier diethylpyrocarbonate (DEPC) reduced basal 36Cl− efflux at pHo 7.4 and acid shifted the pHo vs. activity profile of wild-type AE2, suggesting that His residues might be involved in pH sensing. Single His mutants of AE2 were generated and expressed in oocytes. Although mutation of H1029 to Ala severely reduced transport and surface expression, other individual His mutants exhibited wild-type or near-wild-type levels of Cl− transport activity with retention of pHo sensitivity. In contrast to the effects of DEPC on wild-type AE2, pHo sensitivity was significantly alkaline shifted for mutants H1144Y and H1145A and the triple mutants H846/H849/H1145A and H846/H849/H1160A. Although all functional mutants retained sensitivity to pHi, pHi sensitivity was enhanced for AE2 H1145A. The simultaneous mutation of five or more His residues, however, greatly decreased basal AE2 activity, consistent with the inhibitory effects of DEPC modification. The results show that multiple TMD His residues contribute to basal AE2 activity and its sensitivity to pHi and pHo.
Computational model of vectorial potassium transport by cochlear marginal cells and vestibular dark cells
Authors: Quraishi Imran H. , Raphael Robert M.
Published: September 2006

Cochlear marginal cells and vestibular dark cells transport potassium into the inner ear endolymph, a potassium-rich fluid, the homeostasis of which is essential for hearing and balance. We have formulated an integrated mathematical model of ion transport across these epithelia that incorporates the biophysical properties of the major ion transporters and channels located in the apical and basolateral membranes of the constituent cells. The model is constructed for both open- and short-circuit situations to test the extremes of functional capacity of the epithelium and predicts the steady-state voltages, ion concentrations, and transepithelial currents as a function of various transporter and channel densities. We validate the model by establishing that the cells are capable of vectorial ion transport consistent with several experimental measurements. The model indicates that cochlear marginal cells do not make a significant direct contribution to the endocochlear potential and illustrates how changes to the activity of specific transport proteins lead to reduced K+ flux across the marginal and dark cell layers. In particular, we investigate the mechanisms of loop diuretic ototoxicity and diseases with hearing loss in which K+ and Cl− transport are compromised, such as Jervell and Lange-Nielsen syndrome and Bartter syndrome, type IV, respectively. Such simulations demonstrate the utility of compartmental modeling in investigating the role of ion homeostasis in inner ear physiology and pathology.
M1and M2Muscarinic Acetylcholine Receptor Subtypes Mediate Ca2+Channel Current Inhibition in Rat Sympathetic Stellate Ganglion Neurons
Authors: Yang Qing , Sumner Andrew D. , Puhl Henry L. , Ruiz-Velasco Victor
Published: September 2006

Muscarinic acetylcholine receptors (mAChRs) are known to mediate the acetylcholine inhibition of Ca2+channels in central and peripheral neurons. Stellate ganglion (SG) neurons provide the main sympathetic input to the heart and contribute to the regulation of heart rate and myocardial contractility. Little information is available regarding mAChR regulation of Ca2+channels in SG neurons. The purpose of this study was to identify the mAChR subtypes that modulate Ca2+channel currents in rat SG neurons innervating heart muscle. Accordingly, the modulation of Ca2+channel currents by the muscarinic cholinergic agonist, oxotremorine-methiodide (Oxo-M), and mAChR blockers was examined. Oxo-M–mediated mAChR stimulation led to inhibition of Ca2+currents through voltage-dependent (VD) and voltage-independent (VI) pathways. Pre-exposure of SG neurons to the M1receptor blocker, M1-toxin, resulted in VD inhibition of Ca2+currents after Oxo-M application. On the other hand, VI modulation of Ca2+currents was observed after pretreatment of cells with methoctramine (M2mAChR blocker). The Oxo-M–mediated inhibition was nearly eliminated in the presence of both M1and M2mAChR blockers but was unaltered when SG neurons were exposed to the M4mAChR toxin, M4-toxin. Finally, the results from single-cell RT-PCR and immunofluorescence assays indicated that M1and M2receptors are expressed and located on the surface of SG neurons. Overall, the results indicate that SG neurons that innervate cardiac muscle express M1and M2mAChR, and activation of these receptors leads to inhibition of Ca2+channel currents through VI and VD pathways, respectively.
Nonuniform Distribution of Reach-Related and Torque-Related Activity in Upper Arm Muscles and Neurons of Primary Motor Cortex
Authors: Kurtzer Isaac , Herter Troy M. , Scott Stephen H.
Published: September 2006

The present study examined the activity of primate shoulder and elbow muscles using a novel reaching task. We enforced similar patterns of center-out movement while the animals countered viscous loads at their shoulder, elbow, both joints, or neither joint. Accordingly, we could examine reach-related activity during the unloaded condition and torque-related activity by comparing activity across load conditions. During unloaded reaching the upper arm muscles exhibited a bimodal distribution of preferred hand direction. Maximal reach-related activity occurred with hand movements mostly toward or away from the body. Arm muscles also exhibited a bimodal distribution of their preferred torque direction. Maximal torque-related activity typically occurred with shoulder-extension/elbow-flexion torque or shoulder-flexion/elbow-extension torque. Similar biases in reach-related and torque-related activity could be reproduced by optimizing a global measure of muscle activity. These biases were also observed in the neural activity of primary motor cortex (M1). The parallels between M1 and muscular activity demonstrate another link between motor cortical processing and the motor periphery and may reflect an optimization process performed by the sensorimotor system.
Dopamine Has Bidirectional Effects on Synaptic Responses to Cortical Inputs in Layer II of the Lateral Entorhinal Cortex
Authors: Caruana Douglas A. , Sorge Robert E. , Stewart Jane , Chapman C. Andrew
Published: September 2006

Dopaminergic modulation of neuronal function has been extensively studied in the prefrontal cortex, but much less is known about its effects on glutamate-mediated synaptic transmission in the entorhinal cortex. The mesocortical dopamine system innervates the superficial layers of the lateral entorhinal cortex and may therefore modulate sensory inputs to this area. In awake rats, systemic administration of the dopamine reuptake inhibitor GBR12909 (10 mg/kg, ip) enhanced extracellular dopamine levels in the entorhinal cortex and significantly facilitated field excitatory postsynaptic potentials (fEPSPs) in layer II evoked by piriform cortex stimulation. An analysis of the receptor subtypes involved in the facilitation of evoked fEPSPs was conducted using horizontal slices of lateral entorhinal cortex in vitro. The effects of 15-min bath application of dopamine on synaptic responses were bidirectional and concentration dependent. Synaptic responses were enhanced by 10 μM dopamine and suppressed by concentrations of 50 and 100 μM. The D1-receptor antagonist SCH23390 (50 μM) blocked the significant facilitation of synaptic responses induced by 10 μM dopamine and the D2-receptor antagonist sulpiride (50 μM) prevented the suppression of fEPSPs observed with higher concentrations of dopamine. We propose here that dopamine release in the lateral entorhinal cortex, acting through D1 receptors, can lead to an enhancement of the salience of sensory representations carried to this region from adjacent sensory cortices.
Hemispheric Mapping of Secondary Somatosensory Cortex in the Rat
Authors: Benison Alexander M. , Rector David M. , Barth Daniel S.
Published: September 2006

This study used high-resolution hemispheric mapping of somatosensory evoked potentials to determine the number and organization of secondary somatosensory areas (SII) in rat cortex. Two areas, referred to as SII and PV (parietoventral), revealed complete (SII) or nearly complete (PV) body maps. The vibrissa and somatic representation of SII was upright, rostrally oriented, and immediately lateral to primary somatosensory cortex (SI), with a dominant face representation. Vibrissa representations in SII were highly organized, with the rows staggered rostrally along the mediolateral axis. Area PV was approximately one fifth the size of SII, and located rostral and lateral to auditory cortex. PV had a rostrally oriented and inverted body representation that was dominated by the distal extremities, with little representation of the face or vibrissae. These data support the conclusion that in the rat, as in other species, SII and PV represent anatomically and functionally distinct areas of secondary somatosensory cortex.
Stimulus Selectivity Is Enhanced by Voltage-Dependent Conductances in Combination-Sensitive Neurons
Authors: Carlson Bruce A. , Kawasaki Masashi
Published: September 2006

Central sensory neurons often respond selectively to particular combinations of stimulus attributes, but we know little about the underlying cellular mechanisms. The weakly electric fish Gymnarchus discriminates the sign of the frequency difference (Df) between a neighbor's electric organ discharge (EOD) and its own EOD by comparing temporal patterns of amplitude modulation (AM) and phase modulation (PM). Sign-selective neurons in the midbrain respond preferentially to either positive frequency differences (Df >0 selective) or negative frequency differences (Df <0 selective). To study the mechanisms of combination sensitivity, we made whole cell intracellular recordings from sign-selective midbrain neurons in vivo and recorded postsynaptic potential (PSP) responses to AM, PM, Df >0, and Df <0. Responses to AM and PM consisted of alternating excitatory and inhibitory PSPs. These alternating responses were in phase for the preferred sign of Df and offset for the nonpreferred sign of Df. Therefore a certain degree of sign selectivity was predicted by a linear sum of the responses to AM and PM. Responses to the nonpreferred sign of Df, but not the preferred sign of Df, were substantially weaker than linear predictions, causing a significant increase in the actual degree of sign selectivity. By using various levels of current clamp and comparing our results to simple models of synaptic integration, we demonstrate that this decreased response to the nonpreferred sign of Df is caused by a reduction in voltage-dependent excitatory conductances. This finding reveals that nonlinear decoders, in the form of voltage-dependent conductances, can enhance the selectivity of single neurons for particular combinations of stimulus attributes.
Beta Bessel distributions
Authors: Gupta Arjun K. , Nadarajah Saralees
Published: September 2006

Three new distributions on the unit interval [0, 1] are introduced which generalize the standard beta distribution. These
distributions involve the Bessel function. Expression is derived
for their shapes, particular cases, and the nth moments.
Estimation by the method of maximum likelihood and Bayes
estimation are discussed. Finally, an application to consumer
price indices is illustrated to show that the proposed
distributions are better models to economic data than one based on
the standard beta distribution.
Universal approximation theorem for Dirichlet series
Authors: Demanze O. , Mouze A.
Published: September 2006

The paper deals with an extension theorem by Costakis and Vlachou
on simultaneous approximation for holomorphic function to the setting of Dirichlet series, which are absolutely convergent in the right half of the complex plane. The derivation operator used in the analytic case is substituted by a weighted backward shift operator in the Dirichlet case. We show the similarities and extensions in comparing both results. Several density results are proved that finally lead to the main theorem on simultaneous
approximation.
Weak Grothendieck′s theorem
Authors: Mezrag Lahcène
Published: September 2006

Let En ⊂ L12n be the n‐dimensional subspace which appeared in Kašin′s theorem such that L12n = En ⊕ En⊥ and the L12n and L22n norms are universally equivalent on both En and En⊥. In this paper, we introduce and study some
properties concerning extension and weak Grothendieck′s theorem
(WGT). We show that the Schatten space Sp for all 0 < p ≤ ∞ does not verify the theorem of extension. We prove
also that Sp fails GT for all 1 ≤ p ≤ ∞ and consequently by one result of Maurey does not satisfy WGT for 1 ≤ p ≤ 2. We conclude by giving a characterization for
spaces verifying WGT.
Irreducible morphisms, the Gabriel‐valued quiver andcolocalizations for coalgebras
Authors: Simson Daniel
Published: September 2006

Given a basic K‐coalgebra C, we study the left Gabriel‐valued quiver (QC, dC) of C by means of irreducible morphisms between indecomposable injective left C‐comodules and by means of the powers radm of the radical rad of the category
C‐inj of the socle‐finite injective left C‐comodules.
Connections between the valued quiver (QC, dC) of C and the valued quiver of a colocalization coalgebra quotient of C are established.
On the basis number of the corona of graphs
Authors: Shakhatreh Mohammad , Al-Rhayyel Ahmad
Published: September 2006

The basis number b(G) of a graph G is defined to be the least
integer k such that G has a k‐fold basis for its cycle
space. In this note, we determine the basis number of the corona
of graphs, in fact we prove that b(v∘T) = 2 for any tree and
any vertex v not in T, b(v∘H) ≤ b(H) + 2, where H is any graph and v is not a vertex of H, also we prove that if
G = G1∘G2 is the corona of two graphs G1 and
G2, then b(G1) ≤ b(G) ≤ max⁡{b(G1), b(G2) + 2}, moreover we prove that if G is a Hamiltonian
graph, then b(v∘G) ≤ b(G) + 1, where v is any vertex not in G, and finally we give a sequence of remarks which gives the
basis number of the corona of some of special graphs.
Standing wave solutions of Schrödinger systems withdiscontinuous nonlinearity in anisotropic media
Authors: Dinu Teodora-Liliana
Published: September 2006

We establish the existence of an entire solution for a class of stationary Schrödinger systems with subcritical discontinuous nonlinearities and lower bounded potentials that blow up at infinity. The proof is based on the critical point theory in the sense of Clarke and we apply Chang′s version of the mountain pass lemma for locally Lipschitz functionals. Our result generalizes in a nonsmooth framework a result of
Rabinowitz (1992) related to entire solutions of the Schrödinger equation.
Variational inequality problems in H‐spaces
Authors: Behera Akrur , Das Prasanta Kumar
Published: September 2006

The concept of η‐invex set is explored and the
concept of T‐η‐invex function is introduced.
These concepts are applied to the generalized vector variational
inequality problems in ordered topological vector spaces. The
study of variational inequality problems is extended to H‐spaces and differentiable n‐manifolds. The solution of
complementarity problem is also studied in the presence
of fixed points or Lefschetz number.
A note on stable iterated function systems
Authors: Mimna Roy A. , Smotzer Thomas
Published: September 2006

The properties of continuous stable iterated function systems are
investigated, and equicontinuity is studied in relation to
stable iterated function systems.
On a characterization of the lattice of subsystems of a transition system
Authors: Mavoungou J. P. , Nkuimi-Jugnia C.
Published: September 2006

It was first proved by Birkhoff and Frink, and the result now
belongs to the folklore, that any algebraic lattice is up to
isomorphism the lattice of subuniverses of a universal
algebra. A study of subsystems of a transition system
yields a new algebraic concept, that of a strongly algebraic
lattice. We give here a representation theorem to the manner of
Birkhoff and Frink of such lattices.
Existence and uniform decay of solutions for a class ofgeneralized plate‐membrane‐like systems
Authors: Liu Haihong , Su Ning
Published: September 2006

We study the global existence, uniqueness, and asymptotic behavior
of solutions for a class of generalized plate‐membrane‐like
systems with nonlinear damping and source acting both interior and
on boundary.
Combinatorial integers (m,nj) and Schubert calculus in the integral cohomology ring of infinite smooth flag manifolds
Authors: Özel Cenap , Yilmaz Erol
Published: September 2006

We discuss the calculation of integral cohomology ring of LG/T and ΩG. First we describe the root system and Weyl group of LG, then we give some homotopy equivalences on the loop groups and homogeneous spaces, and calculate the cohomology ring structures of LG/T and ΩG for affine group . We introduce combinatorial integers which play a crucial role in our calculations and give some interesting identities among these integers. Last we calculate generators for ideals and rank of each module of graded integral cohomology algebra in the local coefficient ring ℤ[1/2].
Dimension theory and fuzzy topological spaces
Authors: Benchalli S. S. , Ittanagi B. M. , Patil P. G.
Published: September 2006

J. M. Aarts introduced and studied a new dimension function,
Hind, in 1975 and obtained several results on this function. In
this paper, a new local inductive dimension function called local
huge inductive dimension function denoted by locHind is introduced and studied. Furthermore, an effort is made to
introduce and study dimension functions for fuzzy topological
spaces. It has been possible to introduce and study the small
inductive dimension function indfX and large inductive
dimension function indfX for a fuzzy topological space X.
A note on almost contra‐precontinuous functions
Authors: Baker C. W. , Ekici Erdal
Published: September 2006

New characterizations of almost contra‐precontinuity are
presented. These characterizations are used to develop a new weak
form of almost contra‐precontinuity. This new weak form is then
used to extend several results in the literature concerning almost
contra‐precontinuity.
Intercomparison of the Southern Ocean Circulations in IPCC Coupled Model Control Simulations
Authors: Russell Joellen L. , Stouffer Ronald J. , Dixon Keith W.
Published: September 2006

The analyses presented here focus on the Southern Ocean as simulated in a set of global coupled climate model control experiments conducted by several international climate modeling groups. Dominated by the Antarctic Circumpolar Current (ACC), the vast Southern Ocean can influence large-scale surface climate features on various time scales. Its climatic relevance stems in part from it being the region where most of the transformation of the World Ocean’s water masses occurs. In climate change experiments that simulate greenhouse gas–induced warming, Southern Ocean air–sea heat fluxes and three-dimensional circulation patterns make it a region where much of the future oceanic heat storage takes place, though the magnitude of that heat storage is one of the larger sources of uncertainty associated with the transient climate response in such model projections. Factors such as the Southern Ocean’s wind forcing, heat, and salt budgets are linked to the structure and transport of the ACC in ways that have not been expressed clearly in the literature. These links are explored here in a coupled model context by analyzing a sizable suite of preindustrial control experiments associated with the forthcoming Intergovernmental Panel on Climate Change’s Fourth Assessment Report. A framework is developed that uses measures of coupled model simulation characteristics, primarily those related to the Southern Ocean wind forcing and water mass properties, to allow one to categorize, and to some extent predict, which models do better or worse at simulating the Southern Ocean and why. Hopefully, this framework will also lead to increased understanding of the ocean’s response to climate changes.
Improving SST Anomaly Simulations in a Layer Ocean Model with an Embedded Entrainment Temperature Submodel
Authors: Zhang Rong-Hua , Busalacchi Antonio J. , Murtugudde Raghuram G.
Published: September 2006

In this study, an improved sea surface temperature (SST) anomaly (SSTA) solution for the tropical Pacific is presented by explicitly embedding into a layer ocean general circulation model (OGCM) a separate SSTA submodel with an empirical parameterization for the temperature of subsurface water entrained into the ocean mixed layer (Te). Instead of using subsurface temperature directly from the OGCM, Te anomalies for the embedded SSTA submodel are calculated from a historical data-based empirical procedure in terms of sea level (SL) anomalies simulated from the OGCM. An inverse modeling approach is first adopted to estimate Te anomalies from the SSTA equation using observed SST and simulated upper-ocean currents from the OGCM. A relationship between Te and SL anomalies is then obtained by utilizing an empirical orthogonal function (EOF) analysis technique. The empirical Te parameterization optimally leads to a better balanced depiction of the subsurface effect on SST variability by the mean upwelling of anomalous subsurface temperature and vertical mixing in the equatorial Pacific. As compared with a standard OGCM simulation, SSTA simulations from the embedded submodel exhibit more realistic variability, with significantly increased correlation and reduced SSTA errors due to the optimized empirical Te parameterization. In the Niño-3 region (5°S–5°N, 150°–90°W), the anomaly correlation and root-mean-square (RMS) error of the simulated SST anomalies for the period 1963–96 from the standard OGCM are 0.74° and 0.58°C, while from the embedded SSTA submodel they are 0.94° and 0.29°C in the Te-dependent experiment, and 0.86° and 0.41°C in the experiment with one-dependent-year data excluded, respectively. Cross validation and sensitivity experiments to training periods for building the Te parameterization are made to illustrate the robustness and effectiveness of the approach. Moreover, the impact on simulations of SST anomalies and El Niño are examined in hybrid coupled atmosphere–ocean models (HCMs) consisting of the OGCM and a statistical atmospheric wind stress anomaly model that is constructed from a singular value decomposition (SVD) analysis. Results from coupled runs with and without embedding the SSTA submodel are compared. It is demonstrated that incorporating the embedded SSTA submodel in the context of an OGCM has a significant impact on performance of the HCMs and the behavior of the coupled system, with more realistic simulations of interannual SST anomalies (e.g., the amplitude and structure) in the tropical Pacific.
Precipitation Characteristics in Eighteen Coupled Climate Models
Authors: Dai Aiguo
Published: September 2006

Monthly and 3-hourly precipitation data from twentieth-century climate simulations by the newest generation of 18 coupled climate system models are analyzed and compared with available observations. The characteristics examined include the mean spatial patterns, intraseasonal-to-interannual and ENSO-related variability, convective versus stratiform precipitation ratio, precipitation frequency and intensity for different precipitation categories, and diurnal cycle. Although most models reproduce the observed broad patterns of precipitation amount and year-to-year variability, models without flux corrections still show an unrealistic double-ITCZ pattern over the tropical Pacific, whereas the flux-corrected models, especially the Meteorological Research Institute (MRI) Coupled Global Climate Model (CGCM; version 2.3.2a), produce realistic rainfall patterns at low latitudes. As in previous generations of coupled models, the rainfall double ITCZs are related to westward expansion of the cold tongue of sea surface temperature (SST) that is observed only over the equatorial eastern Pacific but extends to the central Pacific in the models. The partitioning of the total variance of precipitation among intraseasonal, seasonal, and longer time scales is generally reproduced by the models, except over the western Pacific where the models fail to capture the large intraseasonal variations. Most models produce too much convective (over 95% of total precipitation) and too little stratiform precipitation over most of the low latitudes, in contrast to 45%–65% in convective form in the Tropical Rainfall Measuring Mission (TRMM) satellite observations. The biases in the convective versus stratiform precipitation ratio are linked to the unrealistically strong coupling of tropical convection to local SST, which results in a positive correlation between the standard deviation of Niño-3.4 SST and the local convective-to-total precipitation ratio among the models. The models reproduce the percentage of the contribution (to total precipitation) and frequency for moderate precipitation (10–20 mm day−1), but underestimate the contribution and frequency for heavy (>20 mm day−1) and overestimate them for light (<10 mm day−1) precipitation. The newest generation of coupled models still rains too frequently, mostly within the 1–10 mm day−1 category. Precipitation intensity over the storm tracks around the eastern coasts of Asia and North America is comparable to that in the ITCZ (10–12 mm day−1) in the TRMM data, but it is much weaker in the models. The diurnal analysis suggests that warm-season convection still starts too early in these new models and occurs too frequently at reduced intensity in some of the models. The results show that considerable improvements in precipitation simulations are still desirable for the latest generation of the world’s coupled climate models.
Topographic Control of Basin and Channel Flows: The Role of Bottom Pressure Torques and Friction
Authors: Jackson Laura , Hughes Chris W. , Williams Richard G.
Published: September 2006

The topographical control of western boundary currents within a basin and zonal jets in a channel is investigated in terms of the potential vorticity (PV) and barotropic vorticity (BV: the curl of the depth-integrated velocity) budgets using isopycnic, adiabatic wind–driven experiments. Along the western boundary, the wind-driven transport is returned across latitude lines by the bottom pressure torque, while friction is only important in altering the PV within an isopycnic layer and in allowing a closed circulation. These contrasting balances constrain the geometry of the flow through integral relationships for the BV and PV. For both homogenous and stratified basins with sloping sidewalls, the northward subtropical jet separates from the western wall and has opposing frictional torques on either side of the jet, which cancel in a zonal integral for BV but alter the PV within a layer streamline. In a channel with partial topographic barriers, the bottom pressure torque is again important in returning wind-driven flows along western boundaries and in transferring BV from neighboring wind-driven gyres into a zonal jet. The depth-integrated flow steered by topography controls where the bottom friction alters the PV, which can lead to different PV states being attained for separate subbasins along a channel.
The Different Nature of the Interdecadal Variability of the Thermohaline Circulation under Mixed and Flux Boundary Conditions
Authors: Arzel Olivier , Huck Thierry , Colin de Verdière Alain
Published: September 2006

The differences between the interdecadal variability under mixed and constant flux boundary conditions are investigated using a coarse-resolution ocean model in an idealized flat-bottom single-hemisphere basin. Objective features are determined that allow one type of oscillation to be distinguished versus the other. First, by performing a linear stability analysis of the steady state obtained under restoring boundary conditions, it is shown that the interdecadal variability under constant flux and mixed boundary conditions arises, respectively, from the instability of a linear mode around the mean stratification and circulation and from departure from the initial state. Based on the budgets of density variance, it is shown next that the two types of oscillations have different energy sources: Under the constant-flux boundary condition (the thermal mode), the downgradient meridional eddy heat flux in the western boundary current regions sustains interdecadal variability, whereas under mixed boundary conditions (the salinity mode), a positive feedback between convective adjustment and restoring surface heat flux is at the heart of the existence of the decadal oscillation. Furthermore, the positive correlations between temperature and salinity anomalies in the forcing layer are shown to dominate the forcing of density variance. In addition, the vertical structure of perturbations reveals vertical phase lags at different depths in all tracer fields under constant flux, while under mixed boundary conditions only the temperature anomalies show a strong dipolar structure. The authors propose that these differences will allow one to identify which type of oscillation, if any, is at play in the more exhaustive climate models.
Analytical Solutions for Circular Stratified Eddies of the Reduced-Gravity Shallow-Water Equations
Authors: Dotsenko Sergey , Rubino Angelo
Published: September 2006

A set of new analytical nonstationary solutions of the nonlinear, reduced-gravity shallow-water equations on an f plane in a vertically stably stratified active environment is presented. The solutions, which describe the dynamics of inertially pulsating surface as well as intermediate lens-like stratified vortices, represent an extension of previous analytical solutions to more realistic vortex shapes and structures of the vortex swirl velocity fields in the presence of an arbitrary stable vertical stratification within the active environment. To elucidate aspects of the novelty of the new set of solutions, examples are presented referring to a vertically stratified surface vortex and to a vertically stratified intermediate vortex, both characterized by azimuthal velocity fields that are nonlinear functions of the radius and by layer shapes that largely deviate from paraboloidal shapes. First, a solution describing a five-layer surface “warm core” eddy is analyzed and characteristics resembling characteristics observed in geophysical surface vortices are revealed: Within each layer, the obtained azimuthal velocity shows a realistic distribution, as its maximum is located far from the vortex rim, where it is negligible. Moreover, the obtained azimuthal velocity is largest in the surface layer and decreases monotonically toward the deeper layers. Integral properties of the new stratified solutions significantly differ from the corresponding properties of equivalent, known homogeneous solutions. Significant differences are found, for instance, between the shape of a five-layer vortex and that of its homogenous counterpart having the same mean azimuthal velocity structure. Second, a solution referring to a five-layer intermediate “meddy like” vortex is analyzed: while in each layer the obtained azimuthal velocity is maximum in the interior part of the vortex and decreases toward its center and its periphery, its magnitude is largest in the intermediate layer and it decreases toward the surface and toward the bottom layer, which are characteristics resembling characteristics of observed meddies. The quoted examples demonstrate that the new solutions add substantial realism to the analytical description of oceanic nonlinear geophysical vortices. In the context of the nonlinear reduced-gravity shallow-water equations on an f plane they seem to represent the most general analytical features achievable, which refer to vertically stratified circular vortices characterized by linear radial velocity fields.
Budgetary reforms in two city states: impact on the central budget agency in Hong Kong and Singapore
Authors: Cheung Anthony B.L.
Published: September 2006

This article compares budgetary reforms in Singapore and Hong Kong. Despite similar reform measures being undertaken in line with the global reform trends under new public management, it is found that such reforms per se have not fundamentally altered the institutional configuration of the respective budgetary regimes. While greater financial autonomy and flexibility have been given to departments and ministries, resulting in the central budget agency (CBA) surrendering micro-budgetary control, the latter continues to play a strategic macro-budgetary role at the governmental level. Neither have budgetary relationships moved towards control by performance as implied by the ‘budgeting for results’ objective. Despite their commonalities, Hong Kong has lately displayed a weaker CBA than Singapore, largely due to extra-budgetary factors rooted in their different governance and institutional contexts.
The evolution of Neolithic farming from SW Asian origins to NW European limits
Authors: Colledge Sue , Conolly James , Shennan Stephen
Published: September 2006

The spread of agriculture is here examined from the perspective of changes in the composition of archaeobotantical assemblages. We apply multivariate analysis to a large database of plant assemblages from early Neolithic sites across South-West Asia and Europe and show that there are coherent and meaningful changes in their composition over time, to a large extent driven by a reduction in crop-taxa diversity. We interpret these changes as being partly caused by environmental factors, and partly caused by cultural reasons linked to the relatively rapid expansion of Linearbandkeramik (LBK) groups that inhibited diversification of crops until later in the Neolithic.
Minoan archaeology in the Athens 2004 Olympic Games
Authors: Simandiraki Anna
Published: September 2006

The Athens 2004 Olympic Games presented an opportunity for Greece to celebrate its ancient traditions and modern organizational skills. The organizers used archaeology as theory, iconography, idealism and so on. They particularly focused on Classical antiquity, when the Games were at their height before their modern revival. This article, however, will examine the use of Minoan archaeology. I argue that, although there is no archaeological evidence to connect Minoan archaeology to the original Olympic Games, the modern Greek national narrative adapted it to the current national image of the Olympic Games. I analyse this phenomenon by deconstructing some of its processes, taking Crete as a case study. I also highlight broader issues, concerning the instrumentality of the public domain in the shaping of cultural heritage.
Creating a School Environment for the Effective Management of Cultural Diversity
Authors: Grobler B. R. , Moloi K. C. , Loock C. F. , Bisschoff T. C. , Mestry R. J.
Published: September 2006

This article examines the factors which impact upon the creation of a school environment for the effective management of cultural diversity as legislated for in the directive principles of the South African Schools Act of 1996 and the Schools Education Act of 1995. The two Acts determine that every person shall have the right to basic education and to equal access to schools and centres of learning. It is within this framework that this research was undertaken employing a quantitative research method. The research demonstrated that a school environment for the effective management of cultural diversity can be achieved through creative approaches to professional management and school governance, characterized by a collaborative management style. Managing cultural diversity can often be complicated by communication problems and stereotyping due to differences based on moral, ethical, socio-political and economic issues. The previous divisions of schools under the pre-1994 regime according to departments of education and mother tongue were found to be both statistically and substantially significant as independent variables for the management of cultural diversity.
School Governing Bodies in South Africa
Authors: Heystek Jan
Published: September 2006

This article focuses on the relationship between principals and school governing bodies in South Africa. Although there are several different groups represented on the governing body, this article relates mainly to the role and function of the parental representatives. The parents have a majority on the governing bodies and therefore have an important role to play in the effective functioning of the school. The legislation does not provide enough clarity on the daily functioning of the governing body and this sometimes creates tension between principals and parent governors.
Learning Challenges Involved in Developing Leading for Learning
Authors: Timperley Helen S.
Published: September 2006

The study in this article seeks to understand the learning challenges involved in developing learning-centred leadership in schools. It is based on Southworth’s (1998, 2004) ideas of leadership for improving schools, which comprise promoting learning-centred improvement at all levels through professional development and a focus on the quality of teaching and student learning. An evaluation of an initiative in New Zealand designed to assist leaders to develop such qualities identified three learning challenges when developing this form of leadership. The first of these challenges was that school leaders did not perceive themselves or their skills to be the target of the initiative, despite being nominated as the focus. The second was that they were more concerned about teachers collaborating with one another than whether that collaboration was leading to improved student learning. The third was that they did not put in place robust organizational processes to support evidence-engaged professional learning. Implications for developing learning-centred leadership are discussed, including the kinds of messages conveyed to leaders about the purposes of initiatives designed to develop such leadership.
A South West regional survey to identify education staff development needs in clinical skills and practice
Authors: Goodman Benny , Girot Elizabeth A. , Latter Sue , Jackson Dawn , Watkins Mary
Published: September 2006

This paper reports tentative findings from a survey (undertaken in 2001) of education staff employed to teach nurses and midwives in four highereducation institutions in the South West of England, with specific focus on answers regarding clinical skills and practice within a wider aim of evaluating training needs. A 57 item self-administered postal questionnaire was sent out to 760 educators, 426 were returned with a response rate of 56%. The results were analysed using SPSS version 9, using descriptive statistics focusing on the responses of HE staff and lecturer practitioners on joint appointments. Findings suggest HE staff teach a limited range of (defined) clinical skills, they have varying and wide definitions of clinical skills, less confidence in teaching skills in practice, minimal experience in working in practice settings and difficulties in engagement in practice. They continue to experience role diversity and a wide variation in meeting clinical demands for clinical competence. Definitions of clinical practice and practice skill are explored in relation to the need for nurse teachers to have ‘recent and practical experience of nursing’. A range of education roles are explored.
Seconding healthcare assistants to a pre-registration nursing course
Authors: Gould Dinah , Carr Graham , Kelly Daniel
Published: September 2006

Attrition from traditional pre-registration nursing programmes in the United Kingdom continues to be substantial and, once qualified, new staff nurses experience a number of challenges in adapting to their new role. A possible solution, strongly favoured by the current government, is to second existing healthcare assistants onto pre-registration programmes. The premise is that, because of their previous caring experience and exposure to work in the National Health Service, secondees will be more committed to complete training and will undergo role transition more effectively.

This paper presents an in-depth, qualitative study concerning the role transition of newly qualified staff nurses who had previously been employed as healthcare assistants. Uptake of the scheme had been substantially lower than anticipated, with only a small number of secondees eventually returning to their original wards. Secondees, their ward managers, percerptors and clinical practice facilitators were interviewed and the data were analysed employing the sequence for qualitative data analysis described by Miles and Huberman (1994). Findings suggest that healthcare-assistant secondment may not offer a ready solution to increasing the qualified nursing workforce. Contributory factors include: the length of time required for each newly qualified practitioner to qualify via the secondment route; the degree of commitment required on the part of secondees and university staff; the apparently limited benefits of previous healthcare-assistant experience; and personal costs to the secondees. Secondees described how they had been afraid of not completing the course successfully because of the public nature of failure if they were obliged to return to their original workplaces in the same role as before. This additional pressure has not been anticipated by proponents of secondment schemes and may help to explain why so few eligible candidates applied for secondment.