bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic field-controlled two-way shape memory in CoNiGa single crystals
Authors: Li Y. X. , Liu H. Y. , Meng F. B. , Yan L. Q. , Liu G. D. , Dai X. F. , Zhang M. , Liu Z. H. , Chen J. L. , Wu G. H.
Published: April 2004

A two-way magnetic field controlled shape memory effect has been observed in single crystals of CoNiGa with martensitic transformation temperature ranging from 205 to 341 K. Two-way shape memory with −2.3% strain has been obtained in free samples. By applying a bias field of up to 2 T, the shape memory strain can be continuously controlled from negative 2.3% to positive 2.2% giving it a total strain of 4.5%. The magnetic properties of CoNiGa show that it is a good shape memory material working at relatively high temperature of up to 450 K, and has a lower magnetic anisotropy than NiMnGa.
Self-assembled hexagonal Au particle networks on silicon from Au nanoparticle solution
Authors: Su P. Y. , Hu J. C. , Cheng S. L. , Chen L. J. , Liang J. M.
Published: April 2004

Self-assembled hexagonal Au particle networks, 2–12 μm in cell size, on silicon have been achieved by a simple method. Honeycomb structure of Au nanoparticles on silicon was drop cast from the Au nanoparticle solution under appropriate concentration, evaporation rate, substrate temperature, and humidity. Hexagonal networks with discrete Au particles were generated in samples annealed in N2 ambient. Two-step annealing, i.e., annealing at 400 °C followed by annealing at 1000 °C for 1 h each was found to be effective to improve the regularity of the Au particle network. As the cell size can be adjusted by the tuning of the deposition conditions, the scheme promises to be an effective patterning method without complex lithography.
Heteroepitaxal fabrication and structural characterizations of ultrafine GaN/ZnO coaxial nanorod heterostructures
Authors: An Sung Jin , Park Won Il , Yi Gyu-Chul , Kim Yong-Jin , Kang Hee-Bok , Kim Miyoung
Published: April 2004

We report on heteroepitaxial fabrication and structural characterizations of ultrafine GaN/ZnO coaxial nanorod heterostructures. The coaxial nanorod heterostructures were fabricated by epitaxial growth of a GaN layer on ultrafine ZnO nanorods. Epitaxial growth and precise control of GaN overlayer thickness were obtained by low pressure metalorganic vapor-phase epitaxy. ZnO nanorods grown on Si and sapphire substrates using catalyst-free metalorganic chemical vapor deposition exhibited diameters as small as 7 nm. Furthermore, structural properties of the coaxial nanorod heterostructures were investigated using both synchrotron-radiation x-ray diffraction and high resolution transmission electron microscopy.
Suppressing of optical quenching of deep defect-to-band transitions in AlGaN and GaN/AlGaN heterostructures
Authors: Witte H. , Schrenk E. , Flügge K. , Krtschil A. , Lisker M. , Krost A. , Christen J. , Kuhn B. , Scholz F.
Published: April 2004

Quenching of photocurrent spectroscopy and thermally stimulated currents has been investigated in undoped AlGaN layers and GaN/AlGaN heterostructures grown by metalorganic vapor phase epitaxy on sapphire substrates. The quenching was induced by an additional illumination as well as by an excitation with light below bandgap energy, respectively. In GaN layers, mainly the thermal defect emission band between 210 and 300 K is involved in the quenching processes and there are strong indications of a reduction of the band by incorporation of aluminum. In AlGaN layers, a decrease of quenching with increasing Al content is observed in accordance to a reduction of the height of the thermal emission between 210 and 300 K in these layers. These results are supported by quenching experiments in AlGaN/GaN heterostructures.
Fabrication and ethanol sensing characteristics of ZnO nanowire gas sensors
Authors: Wan Q. , Li Q. H. , Chen Y. J. , Wang T. H. , He X. L. , Li J. P. , Lin C. L.
Published: April 2004

Based on the achievement of synthesis of ZnO nanowires in mass production, ZnO nanowires gas sensors were fabricated with microelectromechanical system technology and ethanol-sensing characteristics were investigated. The sensor exhibited high sensitivity and fast response to ethanol gas at a work temperature of 300 °C. Our results demonstrate the potential application of ZnO nanowires for fabricating highly sensitive gas sensors.
Metal-coated Si springs: Nanoelectromechanical actuators
Authors: Singh J. P. , Liu D.-L. , Ye D.-X. , Picu R. C. , Lu T.-M. , Wang G.-C.
Published: April 2004

We demonstrated a nanoscale electromechanical actuator operation using an isolated nanoscale spring. The four-turn Si nanosprings were grown using the oblique angle deposition technique with substrate rotation, and were rendered conductive by coating with a 10-nm-thick Co layer using chemical vapor deposition. The electromechanical actuation of a nanospring was performed by passing through a dc current using a conductive atomic force microscope (AFM) tip. The electromagnetic force leads to spring compression, which is measured with the same AFM tip. The spring constant was determined from these measurements and was consistent with that obtained from a finite element analysis.
Ferroelectric properties of La and Zr substituted Bi4Ti3O12 thin films
Authors: Zhang S. T. , Chen Y. F. , Wang J. , Cheng G. X. , Liu Z. G. , Ming N. B.
Published: April 2004

Thin films of A-site substituted, B-site substituted, and both A- and B-sites cosubstituted Bi4Ti3O12 (BTO) by La3+ and Zr4+, i.e., Bi3.25La0.75Ti3O12 (BLT), Bi4Ti2.8Zr0.2O12 (BTZ), and Bi3.25La0.75Ti2.8Zr0.2O12 (BLTZ), were fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition. Structures of the films are investigated by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Compared to the well known BLT films, both the BTZ and BLTZ films have larger remanent polarization (Pr) but smaller coercive field (Ec). It is shown experimentally that the oxygen vacancy is the predominant factor determining ferroelectric fatigue. The effects of substitution on structural and ferroelectric properties of BTO are discussed in detail. As a result, the A- and B-sites cosubstitution might be one of the promising ways to improve ferroelectric properties of BTO.
Broadband laser mirrors made from porous silicon
Authors: Zheng W. H. , Reece P. , Sun B. Q. , Gal M.
Published: April 2004

We have designed, fabricated, and tested laser mirrors made entirely from porous silicon (PSi). PSi high reflectors and output couplers were designed for continuous-wave and mode-locked Ti:Sapphire lasers that were tuned between 730 nm and 940 nm. The mode-locked version of this laser produced 80 fs pulses at 85 MHz, parameters very similar to those observed with the commercial mirrors. We also made a PSi-dye laser by inserting a dye-filled cuvette between two PSi mirrors that was pumped from the side with a pulsed, frequency doubled, Nd:YAG laser. Lasers working with the PSi mirrors exhibited stable operation over time.
Growth kinetics of N-face polarity GaN by plasma-assisted molecular-beam epitaxy
Authors: Monroy E. , Sarigiannidou E. , Fossard F. , Gogneau N. , Bellet-Amalric E. , Rouvière J.-L. , Monnoye S. , Mank H. , Daudin B.
Published: April 2004

We have studied the surface kinetics of N-face GaN during molecular-beam epitaxial growth by investigating the Ga wetting and the surface morphology. In the case of N-face GaN, it is not possible to establish the self-regulated Ga bilayer that is used as a surfactant for molecular-beam-epitaxy growth of Ga-face GaN. Indeed, to prevent the accumulation of Ga droplets, growth of the N-face GaN must be performed with less than one monolayer of excess Ga on the growing surface. Optimum surface morphology is achieved when growth is performed at the Ga accumulation limit.
Leakage behavior of the quasi-superlattice stack for multilevel charge storage
Authors: Chang T. C. , Yan S. T. , Liu P. T. , Chen C. W. , Wu H. H. , Sze S. M.
Published: April 2004

The leakage behavior of the quasi-superlattice structure has been characterized by current–voltage measurements at room temperature and 50 K. A resonant tunnelinglike leakage characteristic is observed at low temperature. The resonant tunneling occurs at around 2, 5.2, and 7 V under a gate voltage swept from 0 to 10 V. A concise physical model is proposed to characterize the leakage mechanism of tunneling for the quasi-lattice structure and suggests that the considerations of the operating voltage for the two-bit per cell nonvolatile-memory device need to be taken into account.
Device deformation during low-frequency pulsed operation of high-power diode bars
Authors: Gerhardt Axel , Weik Fritz , QuocTran Tien , Tomm Jens W. , Elsaesser Thomas , Biesenbach Jens , Müntz Holger , Seibold Gabriele , Biermann Mark L.
Published: April 2004

Thermal tuning rates of single emitters in “cm-bar” high-power diode laser arrays are analyzed. We find these tuning rates to consist of purely thermal and mechanical pressure contributions, of −0.48 and −0.08 meV(K)−1, respectively. We estimate the mechanical deformation such a device experiences during pulsed operation to be 0.07%, and then apply an adequate external force to single segments of cm bars. These single segments model the central emitters within the array. Effects that arise due to gradual aging, such as nonequilibrium carrier lifetime decrease, sheet carrier concentration increase, and defect concentration rise are monitored and analyzed over up to 2×106 deformation cycles. These experiments provide the basis for a type of accelerated aging experiment for device testing, especially of devices designed for low-frequency pulsed operation.
Simultaneous measurement of the electronic and lattice temperatures in GaAs/Al0.45Ga0.55As quantum-cascade lasers: Influence on the optical performance
Authors: Spagnolo Vincenzo , Scamarcio Gaetano , Page Hideaki , Sirtori Carlo
Published: April 2004

We measured the electronic and lattice temperatures in steady-state operating GaAs/AlGaAs quantum-cascade lasers, by means of microprobe band-to-band photoluminescence. Thermalized hot-electron distributions with temperatures up to 800 K are established. The comparison of our data with the analysis of the temperature dependence of device optical performances shows that the threshold current is determined by the lattice temperature.
Molecular Cocrystals of Carboxylic Acids. XXV The Utility of Urea in Structure Making with Carboxylic Acids and the Crystal Structures of a Set of Six Adducts with Aromatic Acids
Authors: Smith Graham , Baldry Katherine E. , Byriel Karl A. , Kennard Colin H. L.
Published: April 2004

Molecular adducts of urea with six aromatic carboxylic acids have been
prepared and characterized by using X-ray diffraction methods and infrared
spectroscopy. These compounds are with 5-nitrosalicylic acid
[(C7H5NO5)2(CH4N2O)]
(1), 3,5-dinitrosalicylic acid
[(C7H4N2O7)(CH4N2O)]
(2), 4-aminobenzoic acid
[(C7H7NO2)2(CH4N2O)]
(3), o-phthalic acid
[(C8H6O4)(CH4N2O)]
(4), pyrazine-2,3-dicarboxylic acid
[(C4H4N2O4)(CH4N2O)]
(5) and pyridine-2,6-dicarboxylic acid
[(C7H5NO4)(CH4N2O)2]
(6). In the majority of the adducts, all six potential interactive sites on
the urea molecules are utilized in hydrogen bonding, giving polymeric
structures.
The Preparation of Imidoyl Fluorides
Authors: Rowe Jeffrey E. , Lee Kam , Dolliver Debra D. , Johnson James E.
Published: April 2004

The first general synthesis of imidoyl fluorides is reported here. Irradiation
of the initially formed Z isomers of
N-methoxybenzenecarboximidoyl fluorides led to a
photoequilibrium containing both the E and
Z isomers. The pure E isomers were
able to be isolated from these isomeric mixtures. The n.m.r. spectra of these
isomers are discussed.
G-protein–gated TRP-like Cationic Channel Activated by Muscarinic Receptors
Authors: Zholos Alexander V. , Zholos Andrey A. , Bolton Thomas B.
Published: April 2004

There is little information about the mechanisms by which G-protein–coupled receptors gate ion channels although many ionotropic receptors are well studied. We have investigated gating of the muscarinic cationic channel, which mediates the excitatory effect of acetylcholine in smooth muscles, and proposed a scheme consisting of four pairs of closed and open states. Channel kinetics appeared to be the same in cell-attached or outside-out patches whether the channel was activated by carbachol application or by intracellular dialysis with GTPγS. Since in the latter case G-proteins are permanently active, it is concluded that the cationic channel is the major determinant of its own gating, similarly to the KACh channel (Ivanova-Nikolova, T.T., and G.E. Breitwieser. 1997. J. Gen. Physiol. 109:245–253). Analysis of adjacent-state dwell times revealed connections between the states that showed features conserved among many other ligand-gated ion channels (e.g., nAChR, BKCa channel). Open probability (PO) of the cationic channel was increased by membrane depolarization consistent with the prominent U-shaped I-V relationship of the muscarinic whole-cell current at negative potentials. Membrane potential affected transitions within each closed-open state pair but had little effect on transitions between pairs; thus, the latter are likely to be caused by interactions of the channel with its ligands, e.g., Ca2+ and Gαo-GTP. Channel activity was highly heterogeneous, as was evident from the prominent cycling behavior when PO was measured over 5-s intervals. This was related to the variable frequency of openings (as in the KACh channel) and, especially, to the number of long openings between consecutive long shuttings. Analysis of the underlying Markov chain in terms of probabilities allowed us to evaluate the contribution of each open state to the integral current (from shortest to longest open state: 0.1, 3, 24, and 73%) as PO increased 525-fold in three stages.
Mapping the BKCa Channel's “Ca2+ Bowl”
Authors: Bao Lin , Kaldany Christina , Holmstrand Ericka C. , Cox Daniel H.
Published: April 2004

There is controversy over whether Ca2+ binds to the BKCa channel's intracellular domain or its integral-membrane domain and over whether or not mutations that reduce the channel's Ca2+ sensitivity act at the point of Ca2+ coordination. One region in the intracellular domain that has been implicated in Ca2+ sensing is the “Ca2+ bowl”. This region contains many acidic residues, and large Ca2+-bowl mutations eliminate Ca2+ sensing through what appears to be one type of high-affinity Ca2+-binding site. Here, through site-directed mutagenesis we have mapped the residues in the Ca2+ bowl that are most important for Ca2+ sensing. We find acidic residues, D898 and D900, to be essential, and we find them essential as well for Ca2+ binding to a fusion protein that contains a portion of the BKCa channel's intracellular domain. Thus, much of our data supports the conclusion that Ca2+ binds to the BKCa channel's intracellular domain, and they define the Ca2+ bowl's essential Ca2+-sensing motif. Overall, however, we have found that the relationship between mutations that disrupt Ca2+ sensing and those that disrupt Ca2+ binding is not as strong as we had expected, a result that raises the possibility that, when examined by gel-overlay, the Ca2+ bowl may be in a nonnative conformation.
On Diophantine definability and decidability in some infinite totally real extensions of ℚ
Authors: Shlapentokh Alexandra
Published: April 2004

LetMMbe a number field, andWMW_Ma set of its non-Archimedean primes. Then let<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper O Subscript upper M comma upper W Sub Subscript upper M Subscript Baseline equals left-brace x element-of upper M vertical-bar o r d Subscript German t Baseline x greater-than-or-equal-to 0 comma for-all German t not-an-element-of upper W Subscript upper M Baseline right-brace">OM,WM={x∈M|ordt⁡x≥0,∀t∉WM}O_{M,W_M} = \{x \in M| \operatorname {ord}_{\mathfrak {t}}x \geq 0, \, \forall \mathfrak {t} \, \not \in W_M\}. Let{p1,…,pr}\{p_1,\ldots ,p_r\}be a finite set of prime numbers. LetFinfF_{inf}be the field generated by all thepijp_i^{j}-th roots of unity asj→∞j \rightarrow \inftyandi=1,…,ri=1,\ldots ,r. LetKinfK_{inf}be the largest totally real subfield ofFinfF_{inf}. Then for anyε>0\varepsilon > 0, there exist a number fieldM⊂KinfM \subset K_{inf}, and a setWMW_Mof non-Archimedean primes ofMMsuch thatWMW_Mhas density greater than1−ε1-\varepsilon, andZ\mathbb {Z}has a Diophantine definition over the integral closure ofOM,WMO_{M,W_M}inKinfK_{inf}.
Construction and recognition of hyperbolic 3-manifolds with geodesic boundary
Authors: Frigerio Roberto , Petronio Carlo
Published: April 2004

We extend to the context of hyperbolic 3-manifolds with geodesic boundary Thurston’s approach to hyperbolization by means of geometric triangulations. In particular, we introduce moduli for (partially) truncated hyperbolic tetrahedra, and we discuss consistency and completeness equations. Moreover, building on previous work of Ushijima, we extend Weeks’ tilt formula algorithm, which computes the Epstein-Penner canonical decomposition, to an algorithm that computes the Kojima decomposition. Our theory has been exploited to classify all the orientable finite-volume hyperbolic

3
3

-manifolds with non-empty compact geodesic boundary admitting an ideal triangulation with at most four tetrahedra. The theory is particularly interesting in the case of complete finite-volume manifolds with geodesic boundary in which the boundary is non-compact. We include this case using a suitable adjustment of the notion of ideal triangulation, and we show how this case arises within the theory of knots and links.
The cohomology of certain Hopf algebras associated with 𝑝-groups
Authors: Mauger Justin
Published: April 2004

We study the cohomology

H
∗

(
A
)
=

Ext
A
∗

⁡
(
k
,
k
)

H^*(A)=\operatorname {Ext}_A^*(k,k)

of a locally finite, connected, cocommutative Hopf algebra

A
A

over

k
=

F

p

k=\mathbb {F}_p

. Specifically, we are interested in those algebras

A
A

for which

H
∗

(
A
)

H^*(A)

is generated as an algebra by

H
1

(
A
)

H^1(A)

and

H
2

(
A
)

H^2(A)

. We shall call such algebras semi-Koszul. Given a central extension of Hopf algebras

F
→
A
→
B

F\rightarrow A\rightarrow B

with

F
F

monogenic and

B
B

semi-Koszul, we use the Cartan-Eilenberg spectral sequence and algebraic Steenrod operations to determine conditions for

A
A

to be semi-Koszul. Special attention is given to the case in which

A
A

is the restricted universal enveloping algebra of the Lie algebra obtained from the mod-

p
p

lower central series of a

p
p

-group. We show that the algebras arising in this way from extensions by

Z

/

(
p
)

\mathbb {Z}/(p)

of an abelian

p
p

-group are semi-Koszul. Explicit calculations are carried out for algebras arising from rank 2

p
p

-groups, and it is shown that these are all semi-Koszul for

p
≥
5

p\geq 5

.
Rationality, regularity, and 𝐶₂-cofiniteness
Authors: Abe Toshiyuki , Buhl Geoffrey , Dong Chongying
Published: April 2004

We demonstrate that, for vertex operator algebras of CFT type,

C
2

C_2

-cofiniteness and rationality is equivalent to regularity. For

C
2

C_2

-cofinite vertex operator algebras, we show that irreducible weak modules are ordinary modules and

C
2

C_2

-cofinite,

V
L
+

V_L^+

is

C
2

C_2

-cofinite, and the fusion rules are finite.
Integrals, partitions, and cellular automata
Authors: Holroyd Alexander , Liggett Thomas , Romik Dan
Published: April 2004

We prove that

∫
0
1

−
log
⁡
f
(
x
)

x

d
x
=

π
2

3
a
b

,

\begin{equation*}\int _0^1\frac {-\log f(x)}xdx=\frac {\pi ^2}{3ab},\end{equation*}

where

f
(
x
)

f(x)

is the decreasing function that satisfies

f
a

−

f
b

=

x
a

−

x
b

f^a-f^b=x^a-x^b

, for

0
>
a
>
b

0>a>b

. When

a
a

is an integer and

b
=
a
+
1

b=a+1

we deduce several combinatorial results. These include an asymptotic formula for the number of integer partitions not having

a
a

consecutive parts, and a formula for the metastability thresholds of a class of threshold growth cellular automaton models related to bootstrap percolation.
Uncorrelatedness and orthogonality for vector-valued processes
Authors: Loeb Peter , Osswald Horst , Sun Yeneng , Zhang Zhixiang
Published: April 2004

For a square integrable vector-valued process

f
f

on the Loeb product space, it is shown that vector orthogonality is almost equivalent to componentwise scalar orthogonality. Various characterizations of almost sure uncorrelatedness for

f
f

are presented. The process

f
f

is also related to multilinear forms on the target Hilbert space. Finally, a general structure result for

f
f

involving the biorthogonal representation for the conditional expectation of

f
f

with respect to the usual product

σ
\sigma

-algebra is presented.
Szegö kernels and finite group actions
Authors: Paoletti Roberto
Published: April 2004

In the context of almost complex quantization, a natural generalization of algebro-geometric linear series on a compact symplectic manifold has been proposed. Here we suppose given a compatible action of a finite group and consider the linear subseries associated to the irreducible representations of

G
G

, give conditions under which these are base-point-free and study properties of the associated projective morphisms. The results obtained are new even in the complex projective case.
Homotopy equivalence of two families of complexes
Authors: Boffi Giandomenico , Buchsbaum David
Published: April 2004

An explicit homotopy equivalence is established between two families of complexes, both of which generalize the classical Koszul complex.
Eigenfunctions of the Laplacian acting on degree zero bundles over special Riemann surfaces
Authors: Matone Marco
Published: April 2004

We find an infinite set of eigenfunctions for the Laplacian with respect to a flat metric with conical singularities and acting on degree zero bundles over special Riemann surfaces of genus greater than one. These special surfaces correspond to Riemann period matrices satisfying a set of equations which lead to a number theoretical problem. It turns out that these surfaces precisely correspond to branched covering of the torus. This reflects in a Jacobian with a particular kind of complex multiplication.
The tail boom strake
Authors: Adams Mark , Newman Simon
Published: April 2004

A helicopter tail rotor is required to provide yaw control and essentially that alone. However, it is expected to achieve that role when placed in an aerodynamically difficult location on the aircraft and to operate in a severe aerodynamic environment. This paper describes the pedal travel behaviour caused by aerodynamic interaction between the main rotor wake, the sideways velocity and subsequent forces generated by the tail boom noticed in Sea King helicopters, operating in extreme conditions during the Falklands war. Using earlier research which showed the effectiveness of a modification – a strake – to interrupt the air flow over the tail boom, conducts tests to examine the flow, the effects of the modification, and the side suction force. It also finds that the strake provides a simple and cost‐effective solution to the problem.
Parachute flying physical model and inflation simulation analysis
Authors: Cao Yihua , Xu Hong
Published: April 2004

By means of establishing parachute’s flying physical model, four methods (i.e. tiny segment analysis method, inflating distance method, moment method and simulating canopy shape method) are adopted to analyze and calculate the variations of canopy shape and the parameters of parachute inflation. The results are simply analyzed, and the figures of all the results are compared.
School library Web sites: 1996‐2002
Authors: Clyde Laurel A.
Published: April 2004

In 1996, a content analysis of 50 school library Web sites from nine countries, provided an overview of the then current “state of the art”. In 1999 and 2002, the remaining sites were again subjected to content analysis. This article reports on trends and changes through the six‐year period. While school library Web sites have remained very diverse, there has been considerable development, though that development has been uneven both across the Web sites and through the time period. More than half the sites became more sophisticated in terms of the number of pages and the resources made available through them. A major change since 1996 has been the use of the school library Web site to provide access to electronic resources such as for‐fee online information services, the catalogues of other libraries, and the school library's own OPAC.
The revolt against journal publishers
Authors: Falk Howard
Published: April 2004

In universities, research labs and the libraries that support their work, a revolt against current journal publishing prices and policies is rapidly growing. Underlying the revolt are the new capabilities offered by computer networks, particularly the Internet, to make information easily and widely available. Research work can be posted, reviews can be processed and users can view the results, all online and at very low cost. Framed by these generous online capabilities, the spectacle of libraries unable to pay for needed journals has become unbearable. Faculty, researchers and others who depend on journals for information and professional prestige are coming to feel that their needs are not being met by current journal publishing practices. Universities have begun to realize that they no longer have to accept the terms offered by journal publishers.
Intrinsic “dry” thermal resistance of dry infant bedding during use
Authors: Wilson C.A. , Laing R.M. , Tamura T.
Published: April 2004

The aim of this work was to validate the Wilson and Laing theoretical mathematical model for estimating the intrinsic “dry” thermal resistance of upper‐bedding, and compare the two‐dimensional models commonly used to estimate the “dry” thermal resistance of bedding in use, with the actual intrinsic “dry” thermal resistance measured using an infant thermal manikin. The Wilson and Laing model was the only model used adequately to estimate the intrinsic “dry” thermal used resistance of materials arranged over the infant thermal manikin. Estimation of intrinsic “dry” thermal resistance of bedding during use is not adequate using two‐dimensional models. Further investigation into the relationship between thermal resistance, conditions of use, and SIDS using the Wilson and Laing model is recommended.
Probing plasma membrane microdomains in cowpea protoplasts using lipidated GFP‐fusion proteins and multimode FRET microscopy
Authors: Vermeer J. E. M. , Van Munster E. B. , Vischer N. O. , Gadella T. W. J.
Published: April 2004

Multimode fluorescence resonance energy transfer (FRET) microscopy was applied to study the plasma membrane organization using different lipidated green fluorescent protein (GFP)‐fusion proteins co‐expressed in cowpea protoplasts. Cyan fluorescent protein (CFP) was fused to the hyper variable region of a small maize GTPase (ROP7) and yellow fluorescent protein (YFP) was fused to the N‐myristoylation motif of the calcium‐dependent protein kinase 1 (LeCPK1) of tomato. Upon co‐expressing in cowpea protoplasts a perfect co‐localization at the plasma membrane of the constructs was observed. Acceptor‐photobleaching FRET microscopy indicated a FRET efficiency of 58% in protoplasts co‐expressing CFP‐Zm7hvr and myrLeCPK1‐YFP, whereas no FRET was apparent in protoplasts co‐expressing CFP‐Zm7hvr and YFP. Fluorescence spectral imaging microscopy (FSPIM) revealed, upon excitation at 435 nm, strong YFP emission in the fluorescence spectra of the protoplasts expressing CFP‐Zm7hvr and myrLeCPK1‐YFP. Also, fluorescence lifetime imaging microscopy (FLIM) analysis indicated FRET because the CFP fluorescence lifetime of CFP‐Zm7hvr was reduced in the presence of myrLeCPK1‐YFP. A FRET fluorescence recovery after photobleaching (FRAP) analysis on a partially acceptor‐bleached protoplast co‐expressing CFP‐Zm7hvr and myrLeCPK1‐YFP revealed slow requenching of the CFP fluorescence in the acceptor‐bleached area upon diffusion of unbleached acceptors into this area. The slow exchange of myrLeCPK1‐YFP in the complex with CFP‐Zm7hvr reflects a relatively high stability of the complex. Together, the FRET data suggest the existence of plasma membrane lipid microdomains in cowpea protoplasts.
GFP is the way to glow: bioimaging of the plant endomembrane system
Authors: Brandizzi F. , Irons S. L. , Johansen J. , Kotzer A. , Neumann U.
Published: April 2004

It is less than a decade that the green fluorescent protein (GFP) and its spectral variants have changed the approach to studying the dynamics of the plant secretory pathway. GFP technology has in fact shed new light on secretory events by allowing bioimaging in vivo right to the heart of a plant cell. This review highlights exciting discoveries and the most recent developments in the understanding of morphology and dynamics of the plant secretory pathway achieved with the application of fluorescent proteins.
FM‐dyes as experimental probes for dissecting vesicle trafficking in living plant cells
Authors: Bolte S. , Talbot C. , Boutte Y. , Catrice O. , Read N. D. , Satiat‐Jeunemaitre B.
Published: April 2004

FM‐dyes are widely used to study endocytosis, vesicle trafficking and organelle organization in living eukaryotic cells. The increasing use of FM‐dyes in plant cells has provoked much debate with regard to their suitability as endocytosis markers, which organelles they stain and the precise pathways they follow through the vesicle trafficking network. A primary aim of this article is to assess critically the current status of this debate in plant cells. For this purpose, background information on the important characteristics of the FM‐dyes, and of optimal dye concentrations, conditions of dye storage, and staining and imaging protocols, are provided. Particular emphasis is placed on using the FM‐dyes in double labelling experiments to identity specific organelles. In this way, staining of the Golgi with FM4‐64 has been demonstrated for the first time.
Psychosocial Stages and the Accessibility of Autobiographical Memories Across the Life Cycle
Authors: Conway Martin A. , Holmes Alison
Published: April 2004

Abstract Older adults recalled memories from each decade of life. Memories were classified in terms of the psychosocial stages to which their content corresponded. For the majority of memories it was found that age at encoding corresponded to when specific psychosocial stages would have been most likely to have occurred. In a second experiment older adults recalled memories to cues drawn from psychosocial stages and the same pattern of findings was observed. These findings demonstrate that the goals of the self play a major role in both the encoding and accessibility of autobiographical memories, and they also provide support for Erikson's psychosocial theory of development (1950, 1997).
Four Dimensions of Self‐Defining Memories (Specificity, Meaning, Content, and Affect) and Their Relationships to Self‐Restraint, Distress, and Repressive Defensiveness
Authors: Blagov Pavel S. , Singer Jefferson A.
Published: April 2004

Abstract
This study examines four dimensions of self‐defining memory (specificity, meaning, content, and affect) and their relationship to self‐restraint, distress, and defensiveness. The development and validation of a protocol for measuring specificity, meaning, and affect in self‐defining memories is discussed. Specificity is operationalized as the temporal and detailed specificity of the narrative. Meaning refers to the participant's stepping back from the narrative to derive higher personal meaning or a life lesson. Affect reflects subjective emotion upon recall. Agreement between two raters scoring 1040 memories was κ=.83 for specificity and κ=.72 for meaning. The protocol is compatible with Thorne and McLean's scoring system for content (the types of events in memories). The current study compared individual differences in the four dimensions of 10 self‐defining memories collected from 103 undergraduates to scores of self‐restraint, distress, and repressive defensiveness, as measured by the Weinberger Adjustment Inventory. Memory specificity was inversely related to repressive defensiveness, while greater memory meaning was linked to moderate and high levels of self‐restraint. Memory content and affect predicted individuals' degree of subjective distress. Based on these findings, the authors discuss the place of self‐defining memories in Conway and Pleydell‐Pearce's Self‐Memory System model of autobiographical memory and personality, more generally.
Making Things Better and Learning a Lesson: Experiencing Wisdom Across the Lifespan
Authors: Bluck Susan , Glück Judith
Published: April 2004

Abstract Autobiographical memory narratives concerning times in which individuals said, thought, or did something wise were collected from adolescents and young and old adults. This “wisdom of experience” procedure is shown to be a valid means of studying experienced wisdom in everyday lives across the life span. Results show that all age groups use experienced wisdom to transform negative to positive life situations and are equally likely to link these experienced wisdom events to larger temporal life periods. Young and older adults also relate wisdom experiences to the life story by explaining how they are connected to later life consequences or to the direction that their life has taken. Unlike adolescents, older and, especially, young adults report having learned lessons about themselves or having gained a life philosophy from the wisdom‐related event. Thus, the wisdom‐of‐experience procedure highlights both similarities and differences in the life span manifestation of experienced wisdom.
Cognitive Complexity in Response to Traumatic Experiences
Authors: Woike Barbara , Matic Dina
Published: April 2004

Abstract
Two studies examined how personality motives influence the perception of traumatic events in memory and how such perception may be linked to psychological distress. Participants completed implicit and explicit measures of agentic and communal motives. In Study 1, participants living in New York City at the time of the terrorist attacks wrote their thoughts and feelings about the events of September 11th. In Study 2, participants wrote about a personally traumatic experience. In both studies, they also completed questionnaires on psychological symptoms and stress‐related growth. The memories were then scored for differentiation and integration. Agentic motives correlated with differentiated perceptions and differentiation was linked to dissociative symptoms in Study 2. Communal motives related to integrated perceptions, and integration related to stress‐related growth in both studies. Findings suggest that motives play a significant role in the perception of traumatic and difficult experiences and that these perceptions may be differentially linked to psychological impact.
Inhibitory effects of cranberry juice on attachment of oral streptococci and biofilm formation
Authors: Yamanaka A. , Kimizuka R. , Kato T. , Okuda K.
Published: April 2004

Cranberry juice is known to inhibit bacterial adhesion. We examined the inhibitory effect of cranberry juice on the adhesion of oral streptococci strains labeled with [3H]‐thymidine to saliva‐coated hydroxyapatite beads (s‐HA). When the bacterial cells were momentarily exposed to cranberry juice, their adherence to s‐HA decreased significantly compared with the control (P < 0.01). Their hydrophobicity also decreased dependently with the concentration of cranberry juice. We also evaluated the inhibitory effect of cranberry juice on biofilm formation. By using a microplate system, we found that the high molecular mass constituents of cranberry juice inhibited the biofilm formation of the tested streptococci. The inhibitory activity was related to the reduction of the hydrophobicity. The present findings suggest that cranberry juice component (s) can inhibit colonization by oral streptococci to the tooth surface and can thus slow development of dental plaque.
Comparison of inflammatory changes caused by Porphyromonas gingivalis with distinct fimA genotypes in a mouse abscess model
Authors: Nakano K. , Kuboniwa M. , Nakagawa I. , Yamamura T. , Nomura R. , Okahashi N. , Ooshima T. , Amano A.
Published: April 2004

The fimA gene of Porphyromonas gingivalis, encoding fimbrillin (a subunit protein of fimbriae) has been classified into six genotypes (types I–V and Ib). The genotypic variation was previously suggested to be related to the severity of adult periodontitis in the general population. In this study, we compared inflammatory changes caused by bacterial infection to study pathogenic heterogeneity among the different fimA strains in a mouse abscess model. Bacterial suspensions of 13 P. gingivalis strains representing the six fimA types were subcutaneously injected into female BALB/c mice, and serum sialic acid concentrations were assayed as a quantitative host inflammatory parameter. Type II fimA organisms caused the most significant induction of serum sialic acid, as well as other infectious symptoms, followed by types Ib, IV and V. In contrast, types I and III caused weak inflammatory changes. In addition, fimA mutants of type II strains clearly lost their infectious ability. These findings suggest that fimA genotypic variation affects expression of P. gingivalis virulence.
T‐cell clonality to Porphyromonas gingivalis and human heat shock protein 60s in patients with atherosclerosis and periodontitis
Authors: Yamazaki K. , Ohsawa Y. , Itoh H. , Ueki K. , Tabeta K. , Oda T. , Nakajima T. , Yoshie H. , Saito S. , Oguma F. , Kodama M. , Aizawa Y. , Seymour G. J.
Published: April 2004

Individuals with periodontitis have been reported to have a significantly increased risk of developing coronary heart disease. Several studies have demonstrated that the immune response to heat shock protein 60 (HSP60) may be involved in the pathogenesis of both atherosclerosis and chronic periodontitis. To investigate this possible link between these diseases, cellular and humoral immune responses to HSP60 in atherosclerosis patients were compared with those in periodontitis patients and healthy subjects using human and Porphyromonas gingivalis HSP60 (GroEL) as antigens. Antibody levels to both human and P. gingivalis HSP60s were the highest in atherosclerosis patients, followed by periodontitis patients and healthy subjects. Clonal analysis of the T cells clearly demonstrated the presence of not only human HSP60‐ but also P. gingivalis GroEL‐reactive T‐cell populations in the peripheral circulation of atherosclerosis patients. Furthermore, these HSP60‐reactive T cells seemed to be present in atherosclerotic lesions in some patients. These results suggest that T‐cell clones with the same specificity may be involved in the pathogenesis of the different diseases.
Quantitative detection of periodontal pathogens using real‐time polymerase chain reaction with TaqMan probes
Authors: Kuboniwa M. , Amano A. , Kimura K. R. , Sekine S. , Kato S. , Yamamoto Y. , Okahashi N. , Iida T. , Shizukuishi S.
Published: April 2004

Quantitative analysis, with identification of periodontopathic bacteria, is important for the diagnosis, therapeutic evaluation and risk assessment of periodontal disease. We developed a highly sensitive and specific method using real‐time polymerase chain reaction (PCR) to detect and quantify six periodontal bacteria: Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Treponema denticola, Prevotella intermedia, and Prevotella nigrescens. Species‐specific TaqMan probe/primer sets were designed according to 16S ribosomal RNA gene sequences. Plaque and tongue debris specimens were collected from 10 patients with advanced periodontitis and 10 periodontal healthy individuals and analyzed. All species, except for P. nigrescens, were detected in samples from diseased sites in significantly greater numbers than in those from healthy sites, whereas greater numbers of P. nigrescens were found in the controls. These results suggest that the present real‐time PCR method with the designed probe/primer sets enabled sensitive detection of the six periodontal bacteria, and may also assist future microbial studies of periodontal diseases.
Isolation and characterization of Lactobacillus species inhibiting the formation of Streptococcus mutans biofilm
Authors: Chung J. , Ha E.‐S. , Park H.‐R. , Kim S.
Published: April 2004

Oral bacterium S11 was isolated from the saliva of young children without dental caries and with little or no visible supragingival plaque. The S11 strain showed 99.5% similarity with Lactobacillus fermentum, and was identified on the basis of biochemical characteristics and a 16S rDNA sequence. S11 strain and its culture supernatant significantly inhibited the formation of the insoluble glucan produced by Streptococcus mutans Ingbritt. S11 did not affect the multiplication of S. mutans Ingbritt, but the adherence of S. mutans Ingbritt onto cuvette walls was inhibited completely.
TaqMan real‐time polymerase chain reaction assay for the correlation of Treponema denticola numbers with the severity of periodontal disease
Authors: Yoshida A. , Kawada M. , Suzuki N. , Nakano Y. , Oho T. , Saito T. , Yamashita Y.
Published: April 2004

Treponema denticola has been implicated in periodontitis, and the presence of this organism in periodontal pockets has been investigated. However, qualitative analysis is insufficient for the clinical evaluation of periodontal treatments, and quantification of T. denticola populations is essential for monitoring therapeutic efficacy. Therefore, we developed a quantitative method for T. denticola that uses the TaqMan real‐time polymerase chain reaction assay. Using this system, we evaluated the relative and absolute numbers of this organism in saliva and subgingival plaque. Furthermore, we analyzed the relationship between the numbers of T. denticola and pocket depth, and found a significant positive correlation (P < 0.0001) between these parameters. This report demonstrates the broad potential of real‐time polymerase chain reaction applications in periodontology.
Increased oxidative stress and apoptosis in acute puromycin aminonucleoside nephrosis
Authors: Rincon Jaimar , Romero Maritza , Viera Ninoska , Pedrean˜ez Adriana , Mosquera Jesus
Published: April 2004

Accumulating evidence demonstrates that oxidative stress is one of the underlying mechanisms to induce apoptosis in different biological systems. The aim of this study was to examine the simultaneous presence and correlation between oxidative stress events, apoptosis, apoptosis‐associated proteins and monocyte/macrophage infiltration during the course of acute puromycin aminonucleoside nephrosis (PAN). To induce nephrosis, Sprague‐Dawley rats were injected intraperitoneally with puromycin aminonucleoside and killed at weeks 1 and 2 of nephrosis. Controls represent animals injected with 0.9% saline solution. Kidney sections were homogenized to measure nitric oxide (NO), malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase activities by appropriate enzymatic and biochemical methods. Renal frozen sections were studied for superoxide anion (O2–) by a histochemical method, for apoptosis by TUNEL (terminal‐deoxynucleotidyl‐transferase‐mediated dUTP– digoxigenin nick end labelling) and for apoptosis‐associated protein expression and monocyte/macrophage infiltration by monoclonal antibodies. Increased renal apoptosis, p53, Bax, Bcl‐2 accompanied by increased O2– and NO generation, lipid peroxidation (MDA) and monocyte/macrophage infiltration were found in nephrotic animals. Renal oxidative stress (O2–, NO and MDA) was correlated with apoptosis, p53 expression, monocyte/macrophage cells and proteinuria. Anti‐oxidant molecules (SOD and GSH) remained unchanged apart from a decreased activity of catalase which correlated with glomerular apoptosis. In conclusion, the close correlation between the presence of apoptosis and oxidative events confirms the role of oxidative stress in the apoptosis observed during PAN.
The Importance of Organizational Justice in Personnel Selection: Defining When Selection Fairness Really Matters
Authors: Truxillo Donald M. , Steiner Dirk D. , Gilliland Stephen W.
Published: April 2004

The purpose of this paper is to examine the usefulness of the organizational justice approach to applicant reactions. We begin with an overview of the research relating the fairness of selection procedures (“selection fairness”) to individual and organizational outcomes. Next we propose boundary conditions defining when fairness should matter, the appropriate outcomes to examine in applicant reactions research, and methodological issues limiting the contribution of much of the current literature. We then consider a range of questions that remain to be addressed and new issues such as high‐tech testing. Finally, we propose a series of applied questions and recommendations based on both theory and empirical research.
Applicant Reactions to Different Selection Technology: Face‐to‐Face, Interactive Voice Response, and Computer‐Assisted Telephone Screening Interviews
Authors: Bauer Talya N. , Truxillo Donald M. , Paronto Matthew E. , Weekley Jeff A. , Campion Michael A.
Published: April 2004

This research contributes to the understanding of reactions to different selection screening methods. A sample of students (n=153) experienced one of three types of screening techniques, face‐to‐face interview screenings, telephone interview screenings, and interactive voice response (IVR) screenings, with identical content in a pre‐ to post‐screening longitudinal study. We further examined the role of two important individual differences, cognitive ability and conscientiousness, in attitudes toward the screenings. IVR is a “non‐interpersonal” screening method so it was not surprising that it was rated lower in terms of procedural justice factors such as interpersonal treatment, two–way communication, and openness but what is encouraging is that there were no differences between other labor intensive and costly technologies and IVR on the other procedural justice factors. Therefore, there do not appear to be any major negatives in terms of structural fairness among alternative screening devices implying that organizations can make choices between screening methods based on other factors such as recruitment strategy or cost.
The Impact of Justice and Self‐Serving Bias Explanations of the Perceived Fairness of Different Types of Selection Tests
Authors: Schmitt N. , Oswald F. L. , Kim B. H. , Gillespie M. A. , Ramsay L. J.
Published: April 2004

Reactions to the use of the ACT/SAT, biodata, and situational judgment measures in college admissions decisions were collected from 644 college freshmen. Evaluation of a series of models of fairness perceptions indicated that self‐serving bias and organizational justice explanations may both be responsible for these reactions. Examination of respondents' beliefs about their performance compared with other students' performance also elicited responses that may be attributable to concerns about distributive justice. A variety of perceptual processes may explain fairness perceptions, but from a practical perspective, it may be easiest to manipulate examinees' perceptions of the relevance, and indirectly, the perceived fairness of the selection procedures used to make major selection or admissions decisions.