bluuebunny/crossref_metadata_2025 huggingface dataset:
Type 2 diabetes mellitus contributes to cognitive decline in old
age: A longitudinal population-based study
Authors: HASSING LINDA B. , GRANT MICHAEL D. , HOFER SCOTT M. , PEDERSEN NANCY L. , NILSSON SVEN E. , BERG STIG , MCCLEARN GERALD , JOHANSSON BOO
Published: August 2004

We examined change in neuropsychological test performance related to
type 2 diabetes mellitus across a 6-year interval. A population-based
sample of 274 elderly participants (36 with diabetes and 238 without
diabetes) was examined at four occasions at a 2-year interval. The
participants were 80–93 years of age (M = 82.8 years)
and without dementia at baseline. The test battery included tests of
speed, visuospatial ability, short-term memory, semantic memory,
episodic memory, and the Mini Mental Status Examination. Several
models, taking into account diabetes and demographic data, were
analyzed using SAS Proc Mixed multilevel modeling. At baseline, there
were no significant differences in the neuropsychological tests related
to diabetes. The longitudinal analyses, however, showed that diabetes
was a significant predictor of decline for many of the tests. These
findings points to the conclusion that type 2 diabetes is associated
with accelerated cognitive decline in old age that may result in
dementia. (JINS, 2004, 10, 599–607.)
Confrontation naming does not add incremental diagnostic utility in
MCI and Alzheimer's disease
Authors: TESTA JULIE A. , IVNIK ROBERT J. , BOEVE BRADLEY , PETERSEN RONALD C. , PANKRATZ V. SHANE , KNOPMAN DAVID , TANGALOS ERIC , SMITH GLENN E.
Published: August 2004

As the incidence of dementia increases, there is a growing need to
determine the diagnostic utility of specific neuropsychological tests
in the early diagnosis of Alzheimer's disease (AD). In this study,
the relative utility of Boston Naming Test (BNT) in the diagnosis of AD
was examined and compared to the diagnostic utility of other
neuropsychological measures commonly used in the evaluation of AD.
Individuals with AD (n = 306), Mild Cognitive Impairment (MCI;
n = 67), and cognitively normal subjects (n = 409)
with at least 2 annual evaluations were included. Logistic regression
analysis suggested that initial BNT impairment is associated with
increased risk of subsequent AD diagnosis. However, this risk is
significantly less than that imparted by measures of delayed recall
impairments. A multivariate Cox proportional hazards regression
analysis suggested that BNT impairment imparted no additional risk for
subsequent AD diagnosis after delayed recall impairments were included
in the model. Although BNT impairment occurred in all severity groups,
it was ubiquitous only in moderate to severe dementia. Collectively
these results suggest that although BNT impairments become more common
as AD progresses, they are neither necessary for the diagnosis of AD
nor particularly useful in identifying early AD. (JINS, 2004,
10, 504–512.)
Procedural and declarative memory in obsessive-compulsive disorder
Authors: ROTH ROBERT M. , BARIBEAU JACINTHE , MILOVAN DENISE , O'CONNOR KIERON , TODOROV CRISTO
Published: August 2004

Obsessive-compulsive disorder (OCD) has been associated with frontostriatal abnormality. This has led to the hypothesis that the disorder is characterized by abnormality of procedural memory. However, evidence for either procedural or declarative memory disturbance has been mixed, and few studies have directly assessed both of these forms of memory in the same patient group. In the present study, we assessed encoding and retrieval in declarative memory using the Rey Auditory Verbal Learning Test (RAVLT), and procedural memory using the Pursuit Rotor Task, in 27 adults with OCD and 29 matched healthy controls. Groups did not differ with respect to salient demographic characteristics or memory on the RAVLT. In contrast, patients with OCD performed significantly better than controls during the early, but not later trial blocks of the Pursuit Rotor Task. This pattern of results indicates intact encoding and retrieval in declarative memory, but abnormally enhanced procedural memory during the early course of learning in OCD. These findings may be consistent with striatal overactivation observed in neuroimaging studies of OCD, as well as the prominent role of the striatum during early stages of procedural memory. (JINS, 2004,10, 647–654.)
Novel treatments for expressive aprosodia: A phase I investigation
of cognitive linguistic and imitative interventions
Authors: ROSENBEK JOHN C. , CRUCIAN GREGORY P. , LEON SUSAN A. , HIEBER BETHANY , RODRIGUEZ AMY D. , HOLIWAY BETH , KETTERSON TIMOTHY U. , CIAMPITTI MARIBEL , HEILMAN KENNETH , GONZALEZ-ROTHI LESLIE
Published: August 2004

This study investigated two mechanism-based treatments for expressive
aprosodia, a disturbance in emotional prosody thought to be governed by
the right hemisphere. The 3 participants all suffered right CVA's
resulting in expressive aprosodia. Presence of expressive aprosodia was
determined by performance on two batteries of emotional communication.
A single subject ABAC design was employed in which two treatments, one
imitative and one cognitive linguistic, were assigned in random order.
All participants in this study were randomly assigned to begin with the
cognitive linguistic treatment. Probes of treated and untreated
emotions were completed during baseline and therapy phases. Probe items
were judged by a reliable, trained rater blind to time of testing.
Visual and statistical analyses were completed. These analyses
confirmed that both treatments were active. For example, effect size
calculations confirmed modest to substantial treatment effects for both
treatments in all 3 patients. Replication to increase confidence about
treatment effect and enhance understanding of the neuromechanisms
underlying aprosodia is underway. (JINS, 2004, 10,
786–793.)
A comparison of episodic memory deficits in
neuropathologically-confirmed Dementia with Lewy bodies and
Alzheimer's disease
Authors: HAMILTON JOANNE M. , SALMON DAVID P. , GALASKO DOUGLAS , DELIS DEAN C. , HANSEN LAWRENCE A. , MASLIAH ELIEZER , THOMAS RONALD G. , THAL LEON J.
Published: August 2004

Little is known about possible differences in the memory deficits
that occur in Dementia with Lewy bodies (DLB) and Alzheimer's
disease (AD). We compared 24 autopsy-confirmed DLB and 24 age-,
education-, and MMSE-matched autopsy-confirmed AD patients on the
California Verbal Learning Test (CVLT) and the Wechsler Memory
Scale-Revised Logical Memory subtest. The DLB and AD groups were
similarly impaired on CVLT Total Learning (Trials 1–5) and Long
Delayed Free Recall, but the DLB group demonstrated relative
improvement in Savings scores and on recognition testing compared to
the AD group. Likewise, the patient groups were equally impaired on
Logical Memory immediate and delayed recall, but the DLB group's
Saving scores were significantly better than those of the AD patients.
These results indicate that while both DLB and AD patients exhibit
significant memory impairment, the ability to consolidate information
may be less severely impaired in DLB patients than in AD patients.
(JINS, 2004, 10, 689–697.)
Reading and writing skills in young adults with spina bifida and hydrocephalus
Authors: BARNES MARCIA , DENNIS MAUREEN , HETHERINGTON ROSS
Published: August 2004

Reading and writing were studied in 31 young adults with spina bifida and hydrocephalus (SBH). Like children with this condition, young adults with SBH had better word decoding than reading comprehension, and, compared to population means, had lower scores on a test of writing fluency. Reading comprehension was predicted by word decoding and listening comprehension. Writing was predicted by fine motor finger function, verbal intelligence, and short-term and working memory. These findings are consistent with cognitive models of reading and writing. Writing, but not reading, was related to highest level of education achieved and writing fluency predicted several aspects of functional independence. Reading comprehension and writing remain deficient in adults with SBH and have consequences for educational attainments and functional independence. (JINS, 2004,10, 655–663.)
Prospective and retrospective components in the memory for actions
to be performed in patients with severe closed-head injury
Authors: CARLESIMO GIOVANNI A. , CASADIO PAOLA , CALTAGIRONE CARLO
Published: August 2004

This study investigated the basic mechanisms of the impairment of
memory for actions to be performed in a group of 16 chronic survivors
of severe closed-head injury (CHI). The experimental paradigm allowed
discrimination between the deficit in spontaneously remembering the
intention at the appropriate moment (prospective component of the task)
and the deficit in remembering the specific actions to perform
(retrospective component). The experimental procedure also contrasted a
condition in which the time expiration was marked by the ringing of a
timer (event-based condition) and one in which the time expiration was
not marked by any event and the patient had to monitor the passing of
time and completely self-activate the recall of the intention
(time-based condition). Two other experimental manipulations were
concerned with the duration of the delay interval from the
examiner's instructions to the time expiration (10 vs. 45
min) and the fact that the three actions to be performed could be
functionally related or not. With respect to a group of 16 normal
controls, the patients with CHI were impaired in both the prospective
and retrospective components of the memory for actions. Although an
impairment of episodic memory is a plausible explanation for the poor
retrieval of specific actions to perform, it is unlikely that this
deficit played a major role in the CHI patients' reduced accuracy
in spontaneously recalling the intention when the event occurred or the
time expired. Instead, reduced frequency and less strategic utilization
of time monitoring and/or self-reminding likely played a
significant role in this sense. (JINS, 2004, 10,
679–688.)
Asymmetry of the hippocampus and amygdala in MRI volumetric measurements of normal adults
Authors: PEDRAZA OTTO , BOWERS DAWN , GILMORE ROBIN
Published: August 2004

Multiple studies have explored the relationship between MRI-based volumetric measurements of the hippocampus and amygdala, the degree of volumetric asymmetry of these structures, and symptom manifestation. However, considerable variability exists with regard to the reported volumetric values of these structures. The present study employed meta-analytic procedures to provide a systematic analysis of the normal population parameters of hippocampal and amygdala volumetric asymmetry as well as the absolute intrahemispheric volumes of these structures in normal adults. A literature review of studies published between 1990 and 2002 resulted in a representative sample of 82 studies (N= 3,564 participants) providing volumetric information of the hippocampus and 51 studies (N= 2,000 participants) providing volumetric information of the amygdala. Results revealed that both the hippocampus and the amygdala are reliably asymmetrical structures in normal adults, with larger right hippocampal (D= 0.21,p< .001) and right amygdala (D= 0.09,p< .01) volumes. Additional analyses indicated that differences in MRI magnet field strength and slice thickness values might differentially contribute to volumetric asymmetry estimates. These results expand on previous volumetric normative studies and may be relevant to investigators studying the clinical correlates of hippocampal and amygdala volumes. (JINS, 2004,10, 664–678.)
Effect of side of lesion on neuropsychological performance in childhood stroke
Authors: MAX JEFFREY E.
Published: August 2004

The purpose of the current study was to examine the effect of side of lesion on neuropsychological performance in childhood stroke. While laterality effects have been shown fairly consistently in adults who have experienced stroke, results from studies on children who have experienced childhood stroke are not as clear. Numerous methodological differences between previous studies on laterality effects in childhood stroke make it difficult to draw overall conclusions regarding laterality findings. The current study aimed to study a single group of children who experienced stroke in childhood across a number of cognitive domains. The participants were 13 children/adolescents with left hemisphere lesions and 16 children/adolescents with right hemisphere lesions, with a range of onset from prenatal to 13 years. All participants were administered a broad battery of neuropsychological tests including tests of intelligence, achievement, language skills, visuospatial skills, memory, and executive functioning. No significant differences were found between the groups on any of the measures and the calculated effect sizes were small for all but one of the measures examined. These results have implications for a greater understanding of the ability of the young brain to reorganize after childhood stroke. (JINS, 2004,10, 698–708.)
Parametric manipulation of working memory load in traumatic brain injury: Behavioral and neural correlates
Authors: PERLSTEIN WILLIAM M. , COLE MICHAEL A. , DEMERY JASON A. , SEIGNOUREL PAUL J. , DIXIT NEHA K. , LARSON MICHAEL J. , BRIGGS RICHARD W.
Published: August 2004

Traumatic brain injury (TBI) is often associated with enduring impairments in high-level cognitive functioning, including working memory (WM). We examined WM function in predominantly chronic patients with mild, moderate and severe TBI and healthy comparison subjects behaviorally and, in a small subset of moderate-to-severe TBI patients, with event-related functional magnetic resonance imaging (fMRI), using a visualn-back task that parametrically varied WM load. TBI patients showed severity-dependent and load-related WM deficits in performance accuracy, but not reaction time. Performance of mild TBI patients did not differ from controls; patients with moderate and severe TBI were impaired, relative to controls and mild TBI patients, but only at higher WM-load levels. fMRI results show that TBI patients exhibit altered patterns of activation in a number of WM-related brain regions, including the dorsolateral prefrontal cortex and Broca's area. Examination of the pattern of behavioral responding and the temporal course of activations suggests that WM deficits in moderate-to-severe TBI are due to associative or strategic aspects of WM, and not impairments in active maintenance of stimulus representations. Overall, results demonstrate that individuals with moderate-to-severe TBI exhibit WM deficits that are associated with dysfunction within a distributed network of brain regions that support verbally mediated WM. (JINS, 2004,10, 724–741.)
Verbal learning and memory after childhood stroke
Authors: LANSING AMY E. , MAX JEFFREY E. , DELIS DEAN C. , FOX PETER T. , LANCASTER JACK , MANES FACUNDO F. , SCHATZ AMY
Published: August 2004

Verbal learning and memory (VLM) following pediatric stroke was characterized in a cross-sectional neuropsychological and neuroimaging study of 26 subjects, aged 5 to 17, with a history of pediatric stroke and 26 age, SES, and gender matched orthopedic controls. Further comparisons were made between the VLM profiles of stroke subjects with rightversusleft hemisphere lesions and early (≤12 months)versuslate (>12 months) strokes. Overall, stroke subjects scored significantly lower than control subjects on several VLM indices (California Verbal Learning Test–Children; CVLT–C), as well as on measures of intellectual functioning (IQ) and auditory attention/working memory (Digit Span). Subgroup analyses of the stroke population foundnosignificant differences in VLM, Digit Span, Verbal IQ or Performance IQ when left-hemisphere lesion subjects were compared to right-hemisphere lesion subjects. In contrast, early strokes were associated with significantly fewer words recalled after delay, reduced discriminability (fewer correct hits relative to false positive errors on recognition testing), and relatively worse auditory attention/working memory scores (Digit Span). These findings indicate that pediatric stroke subjects demonstrated more VLM impairment than control subjects, and early strokes were associated with greater recall and recognition deficits. In stark contrast with adult-onset stroke, both left- and right-hemisphere lesions during childhood resulted in similar VLM performance. (JINS, 2004,10, 742–752.)
Neuropsychological sequelae of obstructive sleep apnea-hypopnea syndrome: A critical review
Authors: ALOIA MARK S. , ARNEDT J. TODD , DAVIS JENNIFER D. , RIGGS RAINE L. , BYRD DESIREE
Published: August 2004

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a well-recognized clinical sleep disorder that results in chronically fragmented sleep and recurrent hypoxemia. The primary daytime sequelae of the disorder include patient reports of excessive daytime sleepiness, depression, and attention and concentration problems. It has been well established that OSAHS negatively impacts certain aspects of cognitive functioning. The primary goals of this article are to (1) clarify the pattern of cognitive deficits that are specific to OSAHS; (2) identify the specific cognitive domains that improve with treatment; and (3) elucidate the possible mechanisms of cognitive dysfunction in OSAHS. At the conclusion of the paper, we propose a potential neurofunctional theory to account for the etiology of cognitive deficits in OSAHS. Thirty-seven peer-reviewed articles were selected for this review. In general, findings were equivocal for most cognitive domains. Treatment, however, was noted to improve attention/vigilance in most studies and consistently did not improve constructional abilities or psychomotor functioning. The results are discussed in the context of a neurofunctional theory for the effects of OSAHS on the brain. (JINS, 2004,10, 772–785.)
Neuropsychological results and neuropathological findings at autopsy in a case of mild traumatic brain injury
Authors: BIGLER ERIN D.
Published: August 2004

Autopsy studies were undertaken in a 47-year-old college-educated male patient who, 7 months prior to an unexpected death, had sustained a mild traumatic brain injury (TBI) as manifested by brief loss of consciousness and an initial Glasgow Coma Scale score of 14. The patient died from cardiac arrest secondary to an undiagnosed and unknown arteriosclerotic cardiovascular disease as assessed by the coroner's office at the time of autopsy. Gross inspection of the brain at autopsy was normal; however, microscopic analysis demonstrated what were considered trauma findings of hemosiderin-laden macrophages in the perivascular space and macrophages in the white matter, particularly the section taken from the frontal lobe. The patient had partially returned to work at the time of death, but had encountered problems with diminished cognitive performance in his work as an appraiser. Neuropsychological studies were generally within normal limits although several tests of either speed of processing or short-term memory showed lower than expected performance. This case demonstrates the presence of subtle neuropathological changes in the brain of a patient who sustained a mild TBI and was still symptomatic for the residual effects of the injury 7 months post injury when he unexpectedly died. (JINS, 2004,10, 794–806.)
Mapping of Process-Induced Dopant Redistributions by Electron Holography
Authors: Rau Wolf-Dieter , Orchowski Alexander
Published: August 2004

We present and review dopant mapping examples in semiconductor device structures by electron holography and outline their potential applications for experimental investigation of two-dimensional (2D) dopant diffusion on the nanometer scale. We address the technical challenges of the method when applied to transistor structures with respect to quantification of the results in terms of the 2Dp–njunction potential and critically review experimental boundary conditions, accuracy, and potential pitfalls. By obtaining maps of the inner electrostatic potential before and after anneals typically used in device processing, we demonstrate how the “vertical” and “lateral” redistribution of boron during device fabrication can directly be revealed. Such data can be compared with the results of process simulation to extract the fundamental parameters for dopant diffusion in complex device structures.
Some Chicago Aberrations
Authors: Crewe A.V.
Published: August 2004

This article presents my reminiscences of the work in Chicago on the correction or reduction of lens aberrations. Studies began in the early 1960s and extended over a period of almost 40 years, although it was never the primary focus of the work of the laboratory. The account is almost entirely based on my own memory, which is not a very reliable instrument. It is not intended to be a review and is more accurately describable as a personal recollection.
Measurement of X-ray Emission Efficiency for K-lines
Authors: Procop M.
Published: August 2004

Results for the X-ray emission efficiency (counts per C per sr) of
K-lines for selected elements (C, Al, Si, Ti, Cu, Ge) and for the first
time also for compounds and alloys (SiC, GaP, AlCu, TiAlC) are
presented. An energy dispersive X-ray spectrometer (EDS) of known
detection efficiency (counts per photon) has been used to record the
spectra at a takeoff angle of 25° determined by the geometry of the
secondary electron microscope's specimen chamber. Overall
uncertainty in measurement could be reduced to 5 to 10% in dependence
on the line intensity and energy. Measured emission efficiencies have
been compared with calculated efficiencies based on models applied in
standardless analysis. The widespread XPP and PROZA models give
somewhat too low emission efficiencies. The best agreement between
measured and calculated efficiencies could be achieved by replacing in
the modular PROZA96 model the original expression for the ionization
cross section by the formula given by Casnati et al. (1982) A discrepancy remains for carbon, probably
due to the high overvoltage ratio.
Determination and Correction of Position Detection Nonlinearity in
Single Particle Tracking and Three-Dimensional Scanning Probe
Microscopy
Authors: Tischer Christian , Pralle Arnd , Florin Ernst-Ludwig
Published: August 2004

A general method is presented for determining and correcting
nonlinear position detector responses in single particle tracking as
used in three-dimensional scanning probe microscopy based on optical
tweezers. The method uses locally calculated mean square displacements
of a Brownian particle to detect spatial changes in the sensitivity of
the detector. The method is applied to an optical tweezers setup, where
the position fluctuations of a microsphere within the optical trap are
measured by an interferometric detection scheme with nanometer
precision and microsecond temporal resolution. Detector sensitivity
profiles were measured at arbitrary positions in solution with a
resolution of approximately 6 nm and 20 nm in the lateral and axial
directions, respectively. Local detector sensitivities are used to
reconstruct the real positions of the particle from the measured
position signals.
Heterogeneity Evaluation of Research Materials for Microanalysis
Standards Certification
Authors: Marinenko Ryna , Leigh Stefan
Published: August 2004

Electron microprobe testing and evaluation procedures to determine
the extent of within- and between-specimen heterogeneity of reference
materials and the experimental uncertainty are described. These
procedures have been developed and used at NIST in the certification of
several NIST Standard Reference Materials (SRMs). In this article, they
have been simplified and updated for general use. Suggestions for
experimental testing of specimens are described and a detailed
description of the statistical evaluation process is included with an
example of a data spreadsheet and instructions for its preparation.
Detection of Mitochondrial Caspase Activity in Real Time In
Situ in Live Cells
Authors: Zhang Yingpei , Haskins Catherine , Lopez-Cruzan Marisa , Zhang Jianhua , Centonze Victoria E. , Herman Brian
Published: August 2004

Apoptosis plays an important role in many physiological and
pathological processes. The initiation and execution of the cell death
program requires activation of multiple caspases in a stringently
temporal order. Here we describe a method that allows real-time
observation of caspase activation in situ in live cells based on
fluorescent resonance energy transfer (FRET) measurement using the
prism and reflector imaging spectroscopy system (PARISS). When a fusion
protein consisting of CFP connected to YFP via an intervening caspase
substrate that has been targeted to a specific subcellular location is
excited with a light source whose wavelength matches the cyan
fluorescent protein (CFP) excitation peak, the energy absorbed by the
CFP fluorophore is not emitted as fluorescence. Instead, the excitation
energy is absorbed by the nearby yellow fluorescent protein (YFP)
fluorophore that is covalently linked to CFP through a short peptide
containing the caspase substrate. Cleavage of the linker peptide by
caspases results in loss of FRET due to the separation of CFP and YFP
fluorophores. Using a mitochondrially targeted CFP–caspase 3
substrate–YFP construct (mC3Y), we demonstrate for the first time
that there is caspase-3-like activity in the mitochondrial matrix of
some cells at very late stage of apoptosis.
“Indirect” High-Resolution Transmission Electron Microscopy: Aberration Measurement and Wavefunction Reconstruction
Authors: Kirkland Angus I. , Meyer Rüdiger R.
Published: August 2004

Improvements in instrumentation and image processing techniques mean that methods involving reconstruction of focal or beam-tilt series of images are now realizing the promise they have long offered. This indirect approach recovers both the phase and the modulus of the specimen exit plane wave function and can extend the interpretable resolution. However, such reconstructions require thea posterioridetermination of the objective lens aberrations, including the actual beam tilt, defocus, and twofold and threefold astigmatism. In this review, we outline the theory behind exit plane wavefunction reconstruction and describe methods for the accurate and automated determination of the required coefficients of the wave aberration function. Finally, recent applications of indirect reconstruction in the structural analysis of complex oxides are presented.
Carbon Nanotube Electrostatic Biprism: Principle of Operation and Proof of Concept
Authors: Cumings John , Zettl A. , McCartney M.R.
Published: August 2004

During in situ transmission electron microscopy (TEM) field emission experiments, carbon nanotubes are observed to strongly diffract the imaging TEM electron beam. We demonstrate that this effect is identical to that of a standard electrostatic biprism. We also demonstrate that the nanotube biprism can be used to capture electron-holographic information.
Analyses of Eutectoid Phase Transformations in Nb–SilicideIn SituComposites
Authors: Bewlay B.P. , Sitzman S.D. , Brewer L.N. , Jackson M.R.
Published: August 2004

Nb–silicide in situ composites have great potential for high-temperature turbine applications. Nb–silicide composites consist of a ductile Nb-based solid solution together with high-strength silicides, such as Nb5Si3and Nb3Si. With the appropriate addition of alloying elements, such as Ti, Hf, Cr, and Al, it is possible to achieve a promising balance of room-temperature fracture toughness, high-temperature creep performance, and oxidation resistance. In Nb–silicide composites generated from metal-rich binary Nb-Si alloys, Nb3Si is unstable and experiences eutectoid decomposition to Nb and Nb5Si3. At high Ti concentrations, Nb3Si is stabilized to room temperature, and the eutectoid decomposition is suppressed. However, the effect of both Ti and Hf additions in quaternary alloys has not been investigated previously. The present article describes the discovery of a low-temperature eutectoid phase transformation during which (Nb)3Si decomposes into (Nb) and (Nb)5Si3, where the (Nb)5Si3possesses the hP16 crystal structure, as opposed to the tI32 crystal structure observed in binary Nb5Si3. The Ti and Hf concentrations were adjusted over the ranges of 21 to 33 (at.%) and 7.5 to 33 (at.%) to understand the effect of bulk composition on the phases present and the eutectoid phase transformation.
Plasmon-Ratio Imaging: A Technique for Enhancing the Contrast of
Second Phases with Reduced Diffraction Contrast in TEM Micrographs
Authors: Carpenter Graham J.C.
Published: August 2004

A technique is proposed for reducing unwanted diffraction contrast
when imaging second phases in crystalline materials using transmission
electron microscopy. With the suggested name of plasmon-ratio imaging,
the technique uses an energy-filtered imaging system to record and
determine a ratio for two images taken at energies in the low loss
region. Unlike core-loss imaging, the use of very thin specimens is not
required. It is concluded that it is often possible to create a ratio
image in which the contrast is dominated by energy loss, that is,
chemical differences, rather than by diffraction effects.
Cytochemical Labeling for Fungal and Host Components in Plant Tissues Inoculated with Fungal Wilt Pathogens
Authors: Ouellette G.B. , Baayen R.P. , Chamberland H. , Simard M. , Rioux D. , Charest P.M.
Published: August 2004

Antibodies to detect pectin in present investigations attached to distinct fibrils in vessel lumina. In carnation infected with an isolate ofFusarium oxysporumf.sp., labeling of pathogen cells also occurred; in a resistant cultivar (cv.), it was coincident with proximate pectin fibrils and linked to altered fungal walls, which was the opposite in the susceptible cv., indicating that hindrance of pathogen ability to degrade pectin may be related to resistance. Labeling of the fungus in culture was nil, except in media containing pectin, showing that pectin is not native to the pathogen. Labeling of fungal walls for cellulose in elm (inoculated withOphiostoma novo-ulmi) and carnation also occurred, linked to adsorbed host wall components. The chitin probe often attached to dispersed matter, in vessel lumina, traceable to irregularly labeled fungal cells and host wall degradation products. With an anti-horseradish peroxidase probe, host and fungal walls were equally labeled, and with a glucosidase, differences of labeling between these walls were observed, depending on pH of the test solution. Fungal extracellular matter and filamentous structures, present in fungal walls, predominantly in another elm isolate (Phaeotheca dimorphospora), did not label with any of the probes used. However, in cultures of this fungus, extracellular material labeled, even at a distance from the colony margin, with an anti-fimbriae probe.
Letter to the Editor: Image Formation in the High-Resolution Transmission Electron Microscope
Authors: O'Keefe Michael A.
Published: August 2004

A recent article in these pages compares STEM images with an image obtained with the One-Ångstrom Microscope (OÅM) at Lawrence Berkeley National Laboratory (LBNL). Although the experimental work is of excellent quality, Diebold et al. (2003) offer an incorrect explanation of the image formation process in the high-resolution transmission electron microscope. It is important that this misinterpretation be corrected before it comes to be accepted as factual by other scientists who are not expert in the field of high-resolution transmission electron microscopy.
Authors' Response
Authors: Diebold A.C. , Foran B. , Kisielowski C. , Muller D.A. , Pennycook S.J. , Principe E. , Stemmer S.
Published: August 2004

The main purpose of the article by A.C. Diebold and coworkers (2003) is to propose a robust method for determination of gate oxide thickness. O'Keefe objects to a statement in this paper that “Lattice images do NOT depict the projected atom columns; instead, they are interference patterns of the directly transmitted beam with diffracted beams.”
Memory Rehabilitation Techniques for People with Early-Stage Dementia
Authors: Clare Linda , Wilson Barbara A.
Published: August 2004

Summary: Errorless learning (EL) can be supported through a variety of specific learning methods, which may vary along other parameters including for example the degree of effortful processing required. In memory rehabilitation for people with early-stage Alzheimer's disease (AD), achieving the optimal balance between elimination of errors and active, effortful processing during learning is likely to be critical. This paper describes a comparison of four different errorless methods in a single case experimental design. The participant, who had a diagnosis of early-stage AD, attempted to relearn forgotten face-name associations using one of four methods: Spaced retrieval, mnemonic elaboration, cueing with increasing assistance, and cueing with decreasing assistance. Best results were achieved in the mnemonic and cueing with increasing assistance conditions, while cueing with decreasing assistance produced the least learning. It is suggested that, within an errorless learning paradigm, strategies requiring more effortful processing may produce superior gains compared to strategies relying on implicit or passive processing. This has important implications for clinical rehabilitation interventions for people with early-stage dementia.
Krankheitseinsicht bei Kranken mit beginnender Demenz: Bericht über ein europäisches Projekt
Authors: Clare Linda , Romero Barbara , Wenz Michael
Published: August 2004

Zusammenfassung: In diesem Beitrag wird über ein europäisches Projekt zum Thema “Krankheitseinsicht in frühen Demenzstadien” informiert. Das Ziel des für zwei Jahre geplanten Projektes (2003-2004) ist es, den aktuellen Wissensstand zu diesem Thema zusammenzutragen, Grundkonzepte in internationalen und interdisziplinären Expertengruppen zu diskutieren sowie betroffene Familien, Selbsthilfegruppen und professionelle Helfer in die Diskussion und Verbreitung der Informationen mit einzubeziehen. Die Ergebnisse einer im Rahmen des Projektes veranstalteten Tagung (11.-13.Mai 2003, Cambridge) haben die Notwendigkeit deutlich gemacht, die Perspektiven von Demenzkranken und ihrer Angehörigen in ihrer ganzen Komplexität zu berücksichtigen.
CERAD-NP und Flexible Battery Approach
Authors: Jahn Thomas , Theml Tina , Diehl Janine , Grimmer Timo , Heldmann Barbara , Pohl Corina , Lautenschlager Nicola , Kurz Alexander
Published: August 2004

Zusammenfassung: In den letzten Jahren hat sich die vom Consortium to Establish a Registry for Alzheimer's Disease vorgeschlagene neuropsychologische Testbatterie (CERAD-NP) als Screening-Instrument zur kognitiven Demenzdiagnostik etabliert. Ausführlichere neuropsychologische Untersuchungen folgen demgegenüber dem Flexible Battery Approach. Wir verglichen die differenzialdiagnostische Eignung beider Ansätze bei ambulanten Patienten mit einer beginnenden Alzheimer-Demenz (N = 70) bzw. mit depressiven Störungen (N = 43). Fast alle Kennwerte beider Testbatterien deckten signifikante (p < .0005) Gruppenunterschiede auf, die in Diskriminanzanalysen korrekte diagnostische Klassifizierungsraten zwischen 88 % und 96 % erlaubten. Effektstärken und Klassifikationsstatistiken belegen, dass neben dem Mini-Mental-Status als Teil der CERAD-NP insbesondere Kennwerte der verbalen Gedächtnisleistung, der Visuokonstruktion und der Wortproduktion differenzialdiagnostisch relevant sind. Die ausführlichere neuropsychologische Untersuchungsbatterie war der CERAD-NP hinsichtlich der Identifikation depressiver Patienten überlegen.
Animated models of extensional basins and passive margins
Authors: Jones Stephen M. , White Nicky , Faulkner Paul , Bellingham Paul
Published: August 2004

We present animated models of the development of the San Jorge, North Falkland, and North Sea extensional sedimentary basins and the Orange, Pearl River Mouth, and Vøring passive continental margins. These animations show the link between strain rate and subsidence and track both compaction and thermal development of the sediment pile. Calculations are based on a two‐dimensional inverse model for extracting the spatial and temporal variation of strain rate from stratigraphic profiles across extensional terrains. This general algorithm requires no a priori assumptions about the number, duration, and intensity of the rifting episodes. Instead, strain rate is allowed to vary smoothly through space and time until misfit between observed and predicted stratigraphy is minimized. Calculated 2‐D and 1‐D strain rate histories are corroborated by the number and duration of rifting episodes determined from independent stratigraphical and structural evidence. The evolving temperature structure of the sediment pile is a function both of porosity, which varies through time as compaction occurs, and of heat flow into the base of the basin, which is determined from the strain rate history. We discuss the implications of the calculated strain rate histories for understanding the regional tectonic development of each basin and margin.
Inferring crustal structure in the Aleutian island arc from a sparse wide‐angle seismic data set
Authors: Van Avendonk Harm J. A. , Shillington Donna J. , Holbrook W. Steven , Hornbach Matthew J.
Published: August 2004

Compressional seismic travel times from a relatively sparse wide‐angle data set hold key information on the structure of a 800 km long section of the central Aleutian arc. Since the source and receiver locations form a swath along the arc crest that is ∼50 km wide, we trace rays in 3‐D for a collection of 8336 seismic refraction and reflection arrivals. We investigate variations in seismic velocity structure parallel to the Aleutian arc, assuming that our result represents average crustal structure across the arc. We explore seismic velocity models that consist of three crustal layers that exhibit smooth variations in structure in the 2‐D vertical plane. We consider the influence of additional constraints and model parameterization in our search for a plausible model for Aleutian arc crust. A tomographic inversion with static corrections for island stations reduces the data variance of a 1‐D starting model by 91%. Our best model has seismic velocities of 6.0–6.5 km/s in the upper crust, 6.5–7.3 km/s in the middle crust, and 7.3–7.7 km/s in the lower crust and a total crustal thickness of 35–37 ± 1 km. A resolution analysis shows that features having a horizontal scale less than 20 km cannot be imaged, but at horizontal length scales of ∼50 km most model features are well resolved. The study indicates that the Aleutian island arc crust is thick compared to other island arcs and strongly stratified and that only the upper 60% of the arc crust has seismic velocities that are comparable to average seismic velocities in continental crust.
Three‐dimensional simulations of inorganic aerosol distributions in east Asia during spring 2001
Authors: Tang Youhua , Carmichael Gregory R. , Seinfeld John H. , Dabdub Donald , Weber Rodney J. , Huebert Barry , Clarke Antony D. , Guazzotti Sergio A. , Sodeman David A. , Prather Kimberly A. , Uno Itsushi , Woo Jung‐Hun , Yienger James J. , Streets David G. , Quinn Patricia K. , Johnson James E. , Song Chul‐Han , Grassian Vicki H. , Sandu Adrian , Talbot Robert W. , Dibb Jack E.
Published: August 2004

In this paper, aerosol composition and size distributions in east Asia are simulated using a comprehensive chemical transport model. Three‐dimensional aerosol simulations for the TRACE‐P and ACE‐Asia periods are performed and used to help interpret actual observations. The regional chemical transport model, STEM‐2K3, which includes the on‐line gas‐aerosol thermodynamic module SCAPE II, and explicitly considers chemical aging of dust, is used in the analysis. The model is found to represent many of the important observed features. The Asian outflow during March and April of 2001 is heavily polluted with high aerosol loadings. Under conditions of low dust loading, SO2 condensation and gas phase ammonia distribution determine the nitrate size and gas‐aerosol distributions along air mass trajectories, a situation that is analyzed in detail for two TRACE‐P flights. Dust is predicted to alter the partitioning of the semivolatile components between the gas and aerosol phases as well as the size distributions of the secondary aerosol constituents. Calcium in the dust affects the gas‐aerosol equilibrium by shifting the equilibrium balance to an anion‐limited status, which benefits the uptake of sulfate and nitrate, but reduces the amount of aerosol ammonium. Surface reactions on dust provide an additional mechanism to produce aerosol nitrate and sulfate. The size distribution of dust is shown to be a critical factor in determining the size distribution of secondary aerosols. As much of the dust mass is found in the supermicron mode (70–90%), appreciable amounts of sulfate and nitrate are found in the supermicron particles. For sulfate the observations and the analysis indicate that 10–30% of sulfate is in the supermicron fraction during dust events; in the case of nitrate, more than 80% is found in the supermicron fraction.
Fundamental questions about water rights and market reallocation
Authors: Matthews Olen Paul
Published: August 2004

Water markets have many advantages for water reallocation. However, water markets do not always function efficiently because the property rights structure was not designed for market transactions. The potential for successful markets can be determined by looking at the 10 fundamental questions relevant to water rights. The questions are relevant to any system of water rights, but the examples used are largely from the western United States. The questions are designed to raise issues about the basic structure of a water rights system. After discussing these issues, the paper turns to recommendations on how a water rights structure could be modified to facilitate markets. The recommendations are not meant to be an end point but are intended too stimulate discussion.
Geothermal fluxes of alkalinity in the Narayani river system of central Nepal
Authors: Evans Matthew J. , Derry Louis A. , France‐Lanord Christian
Published: August 2004

Numerous hot springs flow within the steeply incised gorges of the central Nepal Himalayan front. The spring fluids have total dissolved solids (TDS) up to 7000 mg/L and Na+, and K+ typically comprise >50% of the cationic charge, indicating that high‐temperature silicate alteration is the dominant source of hot spring alkalinity. HCO3− is normally the dominant anion. Sr isotope ratios from the hydrothermal fluids are similar to the range of values found in the host rocks and imply significant fluid‐rock interaction with local lithologies. To determine the impact of the hydrothermal solute load on the local and regional river chemistry, we use a chemical mass balance approach to quantify the hot spring discharge. The springs are ubiquitously enriched in germanium (Ge) with high but variable Ge/Si. Himalayan rivers upstream of the hot spring zones have Ge/Si systematics like other unpolluted rivers, but downstream they are highly anomalous, with Ge/Si from 2 to 20 μmol/mol. Ge and Si appear to behave conservatively during mixing of spring and river, and the large disparity between river and spring [Ge] and Ge/Si ratios makes germanium an effective tracer of hot spring input. We use the Ge/Si mass balance to estimate the spring flux to individual river systems. Our results show that the premonsoon spring flow over the entire Narayani basin is about 2 m3/s (with a factor of 2 uncertainty), or 0.5% of the total Narayani river discharge. We estimate that the springs provide 25 (±15)% of the silicate‐derived alkalinity to the Narayani system during the low‐flow season from October to May. Available monsoon season data indicate that the spring flux increases during the monsoon by a factor of 2–3, but this increased flow is diluted by the up to 10× increase in overall river flow. The annual river discharge‐weighted mean spring flux is 3.0 ± 1.2 m3/s for the Narayani; hydrothermal alteration contributes ∼10% of the annual flux of silicate alkalinity to this large river system.
Solitary structures associated with short large‐amplitude magnetic structures (SLAMS) upstream of the Earth's quasi‐parallel bow shock
Authors: Behlke R. , André M. , Bale S. D. , Pickett J. S. , Cattell C. A. , Lucek E. A. , Balogh A.
Published: August 2004

For the first time, solitary waves (SWs) have been observed within short large‐amplitude magnetic structures (SLAMS) upstream of the Earth's quasi‐parallel bow shock. The SWs often occur as bipolar pulses in the electric field data and move parallel to the background magnetic field at velocities of v = 400–1200 km/s. They have peak‐to‐peak amplitudes in the parallel electric field of up to E′∥ = 65 mV/m and parallel scale sizes of L∥ ∼ 10 λD. The bipolar solitary waves exhibit negative potential structures of ∣Φ∥∣ = 0.4–2.2 V, i.e., eΦ∥/kTe ∼ 0.1. None of the theories commonly used to describe SWs adequately address these negative potential structures moving at velocities above the ion thermal speed in a weakly magnetized plasma.
Stratospheric influence on baroclinic lifecycles and its connection to the Arctic Oscillation
Authors: Wittman Matthew A. H. , Polvani Lorenzo M. , Scott Richard K. , Charlton Andrew J.
Published: August 2004

Using an idealized primitive equation model, we investigate how stratospheric conditions alter the development of baroclinic instability in the troposphere. Starting from the lifecycle paradigm of Thorncroft et al., we consider the evolution of baroclinic lifecycles resulting from the addition of a stratospheric jet to the LC1 initial condition. We find that the addition of the stratospheric jet yields a net surface geopotential height anomaly that strongly resembles the Arctic Oscillation. With the additional modification of the tropospheric winds to resemble the high‐AO climatology, the surface response is amplified by a factor 10 and, though dominated by the tropospheric changes, shows similar sensitivity to the stratospheric conditions.
Uplift of Beta Regio: Three‐dimensional models
Authors: Vezolainen A. V. , Solomatov V. S. , Basilevsky A. T. , Head J. W.
Published: August 2004

Three‐dimensional models of the uplift of Beta Regio caused by a mantle plume satisfy constraints on gravity, topography, rheology, and the uplift rate substantially better than two‐dimensional models. In particular, the uplift time of Beta Regio is reduced to an acceptable 800 million years. Three‐dimensional models give the plume formation depth around 3000 km, which approximately corresponds to the core‐mantle boundary. The results depend only weakly on the initial lithospheric thickness (at the time of global resurfacing), including a very thin initial lithosphere. This implies that the thick present‐day lithosphere (∼400 km) suggested by our models can be reconciled with a thin lithosphere (100–200 km) inferred from the melt generation rates and the flexural rigidity models.