bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and dielectric properties of pyrochlore Bi2Ti2O7 thin films
Authors: Cagnon Joël , Boesch Damien S. , Finstrom Nicholas H. , Nergiz Saide Z. , Keane Sean P. , Stemmer Susanne
Published: August 2007

Bi 2 Ti 2 O 7 thin films were grown by radio-frequency magnetron sputtering on bare and Pt-coated sapphire substrates at low substrate temperatures (∼200 °C). Postdeposition anneals were carried out at different temperatures to crystallize the films. Nearly phase-pure Bi2Ti2O7 thin films with the cubic pyrochlore structure were obtained at annealing temperatures up to 800 °C. Impurity phases, in particular Bi4Ti3O12, formed at higher temperatures. At 1 MHz, the dielectric constants were about 140–150 with a very small tunability and the dielectric loss was about 4×10−3. The dielectric loss increased with frequency. The dielectric properties of Bi2Ti2O7 films are compared to those of pyrochlore bismuth zinc niobate films.
Photogenerated plasmons in GaAs1−xBix
Authors: Yoon S. , Seong M. J. , Fluegel B. , Mascarenhas A. , Tixier S. , Tiedje T.
Published: August 2007

Light scattering measurements in the dilute isoelectronically doped alloy GaAs1−xBix reveal a large free electron population photogenerated by continuous-wave laser excitation at low temperature. Low-temperature time-resolved photoluminescence of the bismuth related near-band-gap states show carrier lifetimes of several nanoseconds. The authors attribute this to trapping of photoexcited holes at bismuth pair or cluster states located near the valence band maximum.
Inverse photoemission with energy resolution better than 200meV
Authors: Budke M. , Renken V. , Liebl H. , Rangelov G. , Donath M.
Published: August 2007

We present a spectrometer for inverse photoemission in the vacuum ultraviolet range with variable energy resolution between 400 and 165meV full width at half maximum. The energy distribution of the electron beam used for excitation can be adjusted between 300 and 125meV by the use of a toroidal 90° electrostatic deflector combined with a slit aperture. The emitted photons are detected by Geiger-Müller counters filled with either acetone or iodine as counting gas. The optical bandpasses of the detectors can be tuned between 100 and 330meV by varying the temperature of their entrance windows. The overall resolution of the spectrometer is determined by measuring the Fermi-level onset in inverse-photoemission data of polycrystalline gold. Furthermore, the resolution enhancement is demonstrated by spectra of image-potential-induced surface states at Cu(001).
Adaptive optics instrumentation in submillimeter/terahertz spectroscopy with a flexible polyvinylidene fluoride cladding hollow waveguide
Authors: Hidaka Takehiko , Ishikawa Akihiro , Kojou Jun-Ichiro , Ikari Tomofumi , Ishikawa Yoh-Ichi , Minamide Hiroaki , Kudoh Akito , Nishizawa Jun-Ichi , Ito Hiromasa
Published: August 2007

A simple instrument has been developed to carry out temperature dependent submillimeter/terahertz-wave spectroscopy using a polyvinylidene fluoride flexible hollow waveguide and an eggplant-shape launching lens.
Mathematical model of a double-coil inductive transducer for measuring electrical conductivity
Authors: Kusmierz Jozef
Published: August 2007

A technique for the contactless measurement of the electrical conductivity of conducting materials using a double-coil inductive transducer is presented. A mathematical model of the transducer has been created and it consists of two cylindrical coils and a tested sample in the form of a cylinder coaxial with the coils. A processing function of the transducer is defined as the ratio of voltages between terminals of the measurement coil with and without the test sample. This processing function depends on the conductivity of the test sample, the dimensions of the sample and of both coils of the transducer (the measurement coil and the excitation coil), and the frequency of the current supplied to the excitation coil. An analytical formula for the processing function is derived; analysis of graphs of this function in different formats enables us to evaluate the influence of all the essential parameters of the transducer. This is a necessary step for both transducer optimization and carrying out of the conductivity measurement of the investigated materials. In order to verify the theoretical predictions, experimental investigations have been performed using a computerized data acquisition system. First, an experimental validation of the obtained analytical formula has been completed using an aluminum sample of known conductivity. Then, the conductivity measurements of a sample made of brass have been carried out. The obtained experimental results confirm the high accuracy of the theoretical analysis.
Measuring two-dimensional components of a flow velocity vector using a hot-wire probe
Authors: Kiełbasa Jan
Published: August 2007

The article presents a single-hot-wire probe adapted to detect the direction of flow velocity. The modification consists of the introduction of a third support which allows to measure voltage at the central point of the wire. The sign of voltage difference ΔU between both parts of the wire is the measure of the direction of flow velocity in a system of coordinates associated with the probe.
Development of a stable source of atomic oxygen with a pulsed high-voltage discharge and its application to crossed-beam reactions
Authors: Lu I-Chung , Huang Wen-Jian , Chaudhuri Chanchal , Chen Wei-Kan , Lee Shih-Huang
Published: August 2007

To investigate the reactions of oxygen atoms with ethene and silane in a crossed-beam condition, we developed a stable, highly intense, and short-pulsed source of atomic oxygen with a transient high-voltage discharge. Mixtures of O2 and He served as discharge media. Utilizing a crossed molecular-beam apparatus and direct vacuum-ultraviolet ionization, we measured the temporal profiles of oxygen atoms and the time-of-flight spectra of reaction products. With O2 3% seeded in He as a discharge medium, oxygen atoms might have a full width as small as 13.5μs at half maximum at a location 193mm downstream from the discharge region. Most population of oxygen atoms is in the ground state P3 but some in the first excited state D1, depending on the concentration of precursor O2. This discharge device analogously generates carbon, nitrogen, and fluorine atoms from precursors CO, N2, and F2, respectively.
Integrated dual grating method for extended range interferometric displacement detection in probe microscopy
Authors: Van Gorp B. , Onaran A. G. , Degertekin F. L.
Published: August 2007

The authors introduce a method that uses quadrature phase-shifted dual gratings to increase the range of optical interferometric displacement detection in phase-sensitive grating based microsensors. The concept is experimentally demonstrated on a surface micromachined probe microscopy structure suspended over a quartz substrate and two reflective gratings. Quadrature phase shift is obtained via a micromachined step in the quartz substrate below one of the gratings. Measurement of the intensity of the reflected diffraction orders from each grating while the mechanical structure is moved using an integrated actuator shows that interferometric sensitivity is maintained well beyond the quarter wavelength limit of similar sensors.
Sr
3
B
2
O
6
:
Ce
3
+
,
Eu
2
+
: A potential single-phased white-emitting borate phosphor for ultraviolet light-emitting diodes
Authors: Chang Chun-Kuei , Chen Teng-Ming
Published: August 2007

The Ce3+∕Eu2+ coactivated Sr3B2O6 phosphors exhibit varied hues from blue through white and eventually to yellow-orange by resonance-type energy transfer from Ce3+ to Eu2+ and tuning the relative proportion of Ce3+∕Eu2+ properly. The authors have demonstrated that electric dipole-dipole interaction dominates the energy transfer mechanism in Sr3B2O6:Ce3+,Eu2+ phosphor, and the critical distance of energy transfer has been estimated to be about 30Å by both spectral overlap and concentration quenching methods. They have also shown that under the excitation of UV radiation, white light is generated by coupling 434 and 574nm emission bands attributed to Ce3+ and Eu2+ radiations, respectively.
Fourier plasmonics: Diffractive focusing of in-plane surface plasmon polariton waves
Authors: Feng Liang , Tetz Kevin A. , Slutsky Boris , Lomakin Vitaliy , Fainman Yeshaiahu
Published: August 2007

An in-plane Fresnel zone plate (FZP) for focusing surface plasmon polariton (SPP) fields has been designed, fabricated, and tested. The fabricated device consists of 400nm tall by 5μm wide amorphous Si-based SPP FZP on an Al film integrated with a pair of two-dimensional nanohole arrays for excitation of the incident and detection of the diffracted SPP fields. Diffracted SPP fields from each Fresnel zone constructively interfere at the expected focal point to produce focusing with threefold intensity enhancement. Temporal and spatial characteristics of the focused SPP fields are studied with time-resolved spatial-heterodyne imaging technique. Good agreement with average power measurements is demonstrated. Diffractive focusing of SPP fields, based on Fourier plasmonics, represents an approach to SPP in-plane microscopy.
Characterization of pyrocarbon coated materials using laboratory based x-ray phase contrast imaging technique
Authors: Kashyap Y. S. , Roy Tushar , Sarkar P. S. , Yadav P. S. , Shukla Mayank , Sinha Amar , Dasgupta K. , Sathiyamoorthy D.
Published: August 2007

In-line x-ray phase contrast is an emerging x-ray imaging technique that promises to improve the contrast in x-ray imaging process. This technique is most suited for x-ray imaging of soft materials, low atomic number elements such as carbon composite fibers, very thin coatings, etc. We have used this new emerging technique for visualization and characterization of the pyrocarbon coated materials using a combination of microfocus x-ray source and x-ray charge coupled device detector. These studies are important for characterization of coating and optimization of various process parameters during deposition. These experiments will help us to exploit the potential of this technique for studies in other areas of material science such as characterization of carbon fibered structures and detection of cracks and flaws in materials. The characterization of the imaging system and optimization of some process parameters for carbon deposition are also described in detail.
Experimental fire behaviour in managed Pinus sylvestris and Picea abies stands of Finland
Authors: Tanskanen Heidi , Granström Anders , Larjavaara Markku , Puttonen Pasi
Published: August 2007

Fire behaviour characteristics were studied in managed Pinus sylvestris L. and Picea abies L. Karst stands in a series of field burning experiments. Stand characteristics, surface fuel moisture content, mid-flame wind speed, rates of spread, flame heights, and torching were recorded. The Canadian Forest Fire Weather Index System (FWI System) and Finnish Fire Risk Index (FFI) were used to evaluate burning conditions and analyse the observed fire behaviour. Mid-flame wind speed was a good predictor (R2 = 0.96 for exponential curve) of the fire spread rates. Torching formed the strongest correlation with the height of the dead branch limit. An increase in predicted fire weather hazard from FWI 4 to FWI 20 (FWI = the FWI code of the FWI System) increased burn coverage remarkably in 15–45-year-old Pinus stands and to a lesser extent in Pinus and Picea clear-cuts, but did not affect 40–60-year-old Picea stands. The FFI was unable to predict burn coverage or any other fire behaviour characteristics.
A critical assessment of the Burning Index in Los Angeles County, California
Authors: Schoenberg Frederic P. , Chang Chien-Hsun , Keeley Jon E. , Pompa Jamie , Woods James , Xu Haiyong
Published: August 2007

The Burning Index (BI) is commonly used as a predictor of wildfire activity. An examination of data on the BI and wildfires in Los Angeles County, California, from January 1976 to December 2000 reveals that although the BI is positively associated with wildfire occurrence, its predictive value is quite limited. Wind speed alone has a higher correlation with burn area than BI, for instance, and a simple alternative point process model using wind speed, relative humidity, precipitation and temperature well outperforms the BI in terms of predictive power. The BI is generally far too high in winter and too low in fall, and may exaggerate the impact of individual variables such as wind speed or temperature during times when other variables, such as precipitation or relative humidity, render the environment ill suited for wildfires.
Sensitivity of a surface fire spread model and associated fire behaviour fuel models to changes in live fuel moisture
Authors: Jolly W. Matt
Published: August 2007

Fire behaviour models are used to assess the potential characteristics of wildland fires such as rates of spread, fireline intensity and flame length. These calculations help support fire management strategies while keeping fireline personnel safe. Live fuel moisture is an important component of fire behaviour models but the sensitivity of existing models to live fuel moisture has not been thoroughly evaluated. The Rothermel surface fire spread model was used to estimate key surface fire behaviour values over a range of live fuel moistures for all 53 standard fuel models. Fire behaviour characteristics are shown to be highly sensitive to live fuel moisture but the response is fuel model dependent. In many cases, small changes in live fuel moisture elicit drastic changes in predicted fire behaviour. These large changes are a result of a combination of the model-calculated live fuel moisture of extinction, the effective wind speed limit and the dynamic load transfer function of some of the fuel models tested. Surface fire spread model sensitivity to live fuel moisture changes is discussed in the context of predicted fire fighter safety zone area because the area of a predicted safety zone may increase by an order of magnitude for a 10% decrease in live fuel moisture depending on the fuel model chosen.
Firebrand generation from burning vegetation
Authors: Manzello Samuel L. , Maranghides Alexander , Mell William E.
Published: August 2007

A series of real-scale fire experiments were performed to determine the size and mass distribution of firebrands generated from Douglas-fir (Pseudotsuga menziesii) trees. The experiments were performed in the Large Fire Laboratory at the National Institute of Standards and Technology. The Douglas-fir trees used for the experiments ranged in total height from 2.6 to 5.2 m and the tree moisture content was varied. An array of pans filled with water was used to collect the firebrands that were generated from the burning trees. This ensured that firebrands would be quenched as soon as they made contact with the pans. The firebrands were subsequently dried and the sizes were measured using callipers and the dry mass was determined using a precision balance. For all experiments performed, the firebrands were cylindrical in shape. The average firebrand size measured from the 2.6-m Douglas-fir trees was 3 mm in diameter, 40 mm in length. The average firebrand size measured for the 5.2-m Douglas-fir trees was 4 mm in diameter with a length of 53 mm. The mass distribution of firebrands produced from two different tree sizes under similar tree moisture levels was similar. The only noticeable difference occurred in the largest mass class. Firebrands with masses up to 3.5 g to 3.7 g were observed for the larger tree height used (5.2 m). The surface area of the firebrands scaled with firebrand weight.
Spatial and temporal patterns of plant functional types under simulated fire regimes
Authors: Pausas Juli G. , Lloret F.
Published: August 2007

In spite of enormous fire suppression advances in Mediterranean countries, large high-intensity fires are still common. The effects on vegetation structure and composition of fire and fire regime changes at large spatial and temporal scales are poorly known, and landscape simulation models may throw some light in this regard. Thus, we studied how the abundance, richness, and spatial distribution of the different plant types are sensitive to the frequency, extent and spatial distribution of wildfires, using a landscape simulation model (FATELAND). We simulated the dynamics of 10 plant functional types (PFTs) defined as combinations of post-fire persistence strategies and life forms, under the following fire scenarios: No Fire, Suppressed (one large fire every 20 years), Prescribed (small fuel reductions every year), Unmanaged-1 (two small fires every year) and Unmanaged-2 (four small fires every year). The results suggest that the different fire regimes generate different spatial fire-recurrence patterns and changes in the proportion of the dominant species. For instance, with increasing fire recurrence, seeder shrubs (i.e. those recruiting new individuals after fire from persisting seed bank) with early reproduction increased and seeder trees decreased, while little variation was found for resprouters. Fire also increased the spatial aggregation of plants, while PFT richness decreased with increasing fire recurrence. The results suggest patterns of changes similar to those reported in field studies, and thus they provide consistent hypotheses on the possible vegetation changes due to different fire scenarios.
Bushfires 'down under': patterns and implications of contemporary Australian landscape burning
Authors: Russell-Smith Jeremy , Yates Cameron P. , Whitehead Peter J. , Smith Richard , Craig Ron , Allan Grant E. , Thackway Richard , Frakes Ian , Cridland Shane , Meyer Mick C. P. , Gill A. Malcolm
Published: August 2007

Australia is among the most fire-prone of continents. While national fire management policy is focused on irregular and comparatively smaller fires in densely settled southern Australia, this comprehensive assessment of continental-scale fire patterning (1997–2005) derived from ~1 km2 Advanced Very High Resolution Radiometer (AVHRR) imagery shows that fire activity occurs predominantly in the savanna landscapes of monsoonal northern Australia. Statistical models that relate the distribution of large fires to a variety of biophysical variables show that, at the continental scale, rainfall seasonality substantially explains fire patterning. Modelling results, together with data concerning seasonal lightning incidence, implicate the importance of anthropogenic ignition sources, especially in the northern wet–dry tropics and arid Australia, for a substantial component of recurrent fire extent. Contemporary patterns differ markedly from those under Aboriginal occupancy, are causing significant impacts on biodiversity, and, under current patterns of human population distribution, land use, national policy and climate change scenarios, are likely to prevail, if not intensify, for decades to come. Implications of greenhouse gas emissions from savanna burning, especially seasonal emissions of CO2, are poorly understood and contribute to important underestimation of the significance of savanna emissions both in Australian and probably in international greenhouse gas inventories. A significant challenge for Australia is to address annual fire extent in fire-prone Australian savannas.
A modular and extensible RNA-based gene-regulatory platform for engineering cellular function
Authors: Win Maung Nyan , Smolke Christina D.
Published: August 2007

Engineered biological systems hold promise in addressing pressing human needs in chemical processing, energy production, materials construction, and maintenance and enhancement of human health and the environment. However, significant advancements in our ability to engineer biological systems have been limited by the foundational tools available for reporting on, responding to, and controlling intracellular components in living systems. Portable and scalable platforms are needed for the reliable construction of such communication and control systems across diverse organisms. We report an extensible RNA-based framework for engineering ligand-controlled gene-regulatory systems, called ribozyme switches, that exhibits tunable regulation, design modularity, and target specificity. These switch platforms contain a sensor domain, comprised of an aptamer sequence, and an actuator domain, comprised of a hammerhead ribozyme sequence. We examined two modes of standardized information transmission between these domains and demonstrate a mechanism that allows for the reliable and modular assembly of functioning synthetic RNA switches and regulation of ribozyme activity in response to various effectors. In addition to demonstrating examples of small molecule-responsive,
in vivo
functional, allosteric hammerhead ribozymes, this work describes a general approach for the construction of portable and scalable gene-regulatory systems. We demonstrate the versatility of the platform in implementing application-specific control systems for small molecule-mediated regulation of cell growth and noninvasive
in vivo
sensing of metabolite production.
Strength statistics of adhesive contact between a fibrillar structure and a rough substrate
Authors: Porwal Pankaj K , Hui Chung Yuen
Published: August 2007

Equal distribution of load among fibrils in contact with a substrate is an important characteristic of fibrillar structures used by many small animals and insects for contact and adhesion. This is in contrast with continuum systems where stress concentration dominates interfacial failure. In this work, we study how adhesion strength of a fibrillar system depends on substrate roughness and variability of the fibril structure, which are modelled using probability distributions for fibril length and fibril attachment strength. Monte Carlo simulations are carried out to determine the adhesion strength statistics where fibril length follows normal or uniform distribution and attachment strength has a power-law form. Our results indicate that the strength distribution is Gaussian (normal) for both the uniform and the normal distributions for length. However, the fibrillar structure having normally distributed lengths has higher strength and lower toughness than one having uniformly distributed lengths. Our simulations also show that an increase in the compliance of the fibrils can compensate for both the substrate roughness and the attachment strength variation. We also show that, as the number of fibrils
n
increases, the load-carrying efficiency of each fibril goes down. For large
n
, this effect is found to be small. Furthermore, this effect is compensated by the fact that the standard deviation of the adhesive strength decreases as

.
Discrimination: A Challenge to First‐Person Authority?
Authors: Fischer Eugen
Published: August 2007

It is no surprise that empirical psychology refutes, again and again, assumptions of uneducated common sense. But some puzzlement tends to arise when scientific results appear to call into question the very conceptual framework of the mental to which we have become accustomed. This paper shall examine a case in point: Experiments on colour‐discrimination have recently been taken to refute an assumption of first‐person authority that appears to be constitutive of our ordinary notion of perceptual experience. The paper is to show that those experiments do not refute this assumption, and will suggest that the impression to the contrary is, ultimately, due to two factors: to misleading imagery and, above all, to mistaken translation from the technical idiom of empirical psychology into the plain English we use every day. This is to take the mystery out of what we shall see to constitute a pretty puzzle; it is to remind us just how careful we need to be when drawing conclusions from results of scientific psychology; and it is to bring out the virtues of methods commonly lumped together under the entirely misleading label of ‘ordinary language philosophy’, of methods far more useful than their common caricature would make one think.
Isolation and assessment of phytate‐hydrolysing bacteria from the DelMarVa Peninsula
Authors: Hill Jane E. , Kysela David , Elimelech Menachem
Published: August 2007

The Delaware–Maryland–Virginia (DelMarVa) Peninsula, flanking one side of the Chesapeake Bay, is home to a substantial broiler chicken industry. As such, it produces a significant amount of manure that is typically composted and spread onto local croplands as a fertilizer. Phytate (myo inositol hexakisphosphate), the major form of organic phosphorus in the manure, can be hydrolysed by microorganisms to produce orthophosphate. Orthophosphate is a eutrophication agent which can lead to algal blooms, hypoxia and fish kills in the Chesapeake Bay and its tributaries. This transect study reveals a subpopulation of heterotrophic, thiosulfate‐utilizing bacteria that can degrade phytate within the watershed as well as its receiving water sediment. Aerobic isolates were typical soil bacteria, e.g. Pseudomonad, Bacillus and Arthrobacter species, as well as a less common Staphylococcus inhabitant. Bacillus pumilus, Staphyloccocus equorum, Arthrobacter bergei and Pseudomonas marginalis strains have not been previously described as phytate‐degrading. Each site along the transect – from manure pile to receiving sediment – was host to a population of bacteria that can degrade phytate and hence, each is a possible non‐point source of orthophosphate pollution. Each new isolate could provide an enzyme additive for monogastric feed, thus reducing the impact of excessive phytate load on the environment.
The Future of Staatsrecht: Dominance, Demise or Demystification?
Authors: Murkens Jo Eric Khushal
Published: August 2007

The relationship between the national and the European legal orders is affected by the way it is theorised by the national constitutional traditions. This article will explore the opposing constitutional assumptions in Germany that underlie two interpretations of what in Anglo‐Saxon countries is known as constitutional law: Staatsrecht and Verfassungsrecht. The two contending visions are generated from different conceptions of the European Union and, especially, the state. The origins of the German constitutional traditions will be historically reconstructed. Although Staatsrecht has historically offered the dominant interpretation of public law, Verfassungsrecht has ‘de‐mystified’ the state. To continue to offer a coherent interpretation Staatsrecht need not abandon the state as its central concept, but will need to re‐examine the content of the concept in light of modern forms of constitutionalism and European integration.
Dementia Poststroke
Authors: Pohjasvaara Tarja , Vataja Risto , Leppävuori Antero , Erkinjuntti Timo
Published: August 2007

Abstract: The frequency of dementia poststroke is high, and stroke considerably increases the risk of dementia. The risk factors for dementia related to stroke are still incompletely understood. In addition to age and low level of education, different combinations of vascular risk factors and stroke features have been associated with poststroke dementia. A single explanation for poststroke dementia is not adequate; rather, multiple factors including stroke features (dysphasia, major dominant stroke syndrome), infarct features (type, side, site, number, and volume), extent and type of white matter lesions (WMLs), degree and site of atrophy, host characteristics (e.g. age, educational level), and risk factors for stroke (e.g. prior cerebrovascular disease, diabetes) each contribute to the risk of dementia poststroke.

Dementia after first ever clinical stroke is also frequent. Cognitive decline is present prior to stroke in up to one‐third of patients developing post‐stroke dementia. Medial temporal lobe atrophy, a marker of an increased risk of Alzheimer's disease (AD), is more frequent in stroke patients who have preexisting dementia or cognitive decline, as well as poststroke dementia. This may be explained by co‐existing AD and cerebrovascular disease (CVD). The magnitude of this mixed dementia (AD with CVD/Vascular Dementia (VaD)) group has been previously underestimated, and it is a diagnostic challenge in the older population.

Dementia due to CVD is a rather advanced stage of is chemic brain changes, and outcome of treatment and prevention may be limited. Accordingly, the focus should be placed on the entire spectrum of cognitive impairment related to CVD, focusing especially the early cognitive changes.
No Association between Presenilin 1 Intron Gene or Butyrylcholinesterase K Variant and Alzheimer's Disease in Japanese Populations
Authors: Yamamoto Yasuji , Sengo Masahito , Yasuda Minoru , Maeda Kiyoshi
Published: August 2007

Background: One of the purposes of this study was to examine whethe apolipoprotein E (ApoE) ɛ4 allele as a risk factor for Alzheimer's disease (AD) may be associated with the higher prevalence of AD in women compared with men. Recently, the polymorphic K variant of the butyrylcholinest erase (BChE‐K) gene and presenilin 1 (PS1) intronic polymorphism have been reported to be associated with AD respectively. Thus we have reexamined the frequency of BChE‐K, PS1 intronic polymorphism, and the ApoE ɛ4 allele in a large series of Japanese AD patients and controls.

Methods: We have genotyped a large series of Japanese AD and age‐and sex‐matched controls by the method of polymerase chain reaction and restriction fragment length polymorphism for ApoE, BChE‐K, and PS1 intronic polymorphism.

Results: The frequency of ApoE ɛ4 allele was significantly higher in AD patients than in controls, confirming the previous reports. In comparison between men and women, the number of individuals carrying one ɛ4 allele was much greater in women with AD than in men with this illness. Kaplan‐Meier analyses, plotting the ɛ4 gene doses against age of onset for men and women, revealed significant differences in age‐of‐onset curves between men and women.
Dementia in Parkinson's Disease: Its Incidence and a Possible Relationship with Dopa‐refractory Symptoms
Authors: Takeda Atsushi , Fujihara Kanae , Kikuchi Akio , Kimpara Teiko , Itoyama Yasuto
Published: August 2007

Background: The diagnostic criteria for dementia in idiopathic Parkinson's disease (PD) remain controversial. In PD, general intelligence is relatively spared, although executive function is commonly impaired.

Methods: Following the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM‐IV), in this study we defined dementia in PD as a combined impairment of memory and executive function, and evaluated its incidence and its relationship with other clinical features.

Results: The prevalence of dementia among patients with PD was estimated to be 20–30% in an outpatient clinic and was found to be associated with the severity of motor impairments, especially Dopa‐refractory symptoms. On the other hand, no relationships were observed between the prevalence of dementia and patient age or age of onset.

Conclusion: These data suggest that cognitive deficits, comprising dementia syndrome in PD, are mainly due to common neurodegenerative processes of non‐dopaminergic systems, but not to other concomitant diseases, such as Alzheimer's disease.
Effect of Presenilin 1 Missense Mutation and Aluminum on Early Neuronal Development of the Mouse Brain
Authors: Fukusho Eriko , Nakamura Yu , Kashiwagi Yujiro , Kudo Takashi , Tanaka Toshihisa , Matsumoto Naohiko , Kida Tomoyuki , Nakano Yuka , Shinosaki Kazuhiro , Takeda Masatoshi
Published: August 2007

Background: The pathology of Alzheimer's disease (AD) has not been fully elucidated. Presenilin 1 (PS1) mutation is one of the major genetic factors of AD, while aluminum is a candidate for the environmental risk factor.

Methods: First, we investigated the influence of PS1 mutation on the neuronal development in ‘knock‐in’ mice of PS1 1213T mutation. Next, the effect of prenatal exposure to aluminum on the neuronal development of the knock‐in mice was examined.

Results: In the newborns with the mutated PS1 allele, a tendency of delayed neurological development was seen and an abnormal distribution of neurofilaments was found, implying that the PS1 mutation might alter early neuronal development. Intraperitoneal administration of aluminum‐maltol resulted in the increase of aluminum in brain tissues of newborns, and in abnormal distribution of neurofilaments. Furthermore, the PS1 mutation promoted a change in neurofilament distribution induced by exposure to aluminum.

Conclusion: Thus, PS1 mutation and aluminum are suggested to affect early neuronal development, as reflected in some aspects of the pathology of AD.
Interrater Reliability of the Todai‐shiki Observational Rating Scale (TORS) for Group Psychotherapy of Elderly Patients with Dementia
Authors: Matsuda Osamu , Kurokawa Yukiko , Saito Masahiko , Maruyama Kaori , Miyamoto Noriko
Published: August 2007

Background: Various types of psychosocial approaches have been developed in the field of dementia patient care. One of these approaches, reminiscence groups, is often applied in the care setting. We developed the Todai‐shiki Observational Rating Scale (TORS) to assess the effectiveness of reminiscence groups, and we examined its interrater reliability in this preliminary study.

Methods: The subjects of the study were nine elderly patients with mild to moderate dementia. The TORS consists of 20 items covering four aspects of the patients' clinical picture: verbal communication, nonverbal communication, attention and interest, and emotion. The intraclass correlation coefficient (ICC) for each item was calculated. The mean ICCs for each item over five sessions were used as a reliable index.

Results: The mean ICCs ranged from 0.53 to 1.00, and averaged 0.83.

Conclusion: This preliminary study suggested that the TORS might be a useful tool to evaluate the effects of group psychotherapy for patients with dementia.
Pathology in Senile Patients with Abnormal Body Sensation
Authors: Takahashi Tohru , Tamaru Tsunemi , Imai Junko , Washizuka Shinsuke , Ozawa Hiroshi , Harada Yuzuru , Morishima Akihito , Amano Naoji
Published: August 2007

Background: Senile people tend to develop abnormal body sensations such as delusion of parasitosis. To discuss the pathology of senile abnormal body sensation, we studied patients with abnormal body sensation, cenesthopathy, and delusion of parasitosis and investigated their age and gender.

Methods: The subjects were a mix of patients reported in Japan and our patients. They were classified into two groups; Group 1 were those with a condition considered to be a somatoform disorder and Group 2 were those with a delusion of parasitosis and chronic tactile hallucinosis.

Results: Group 1 consisted of 29 patients aged 46.4±9.6 years; the male:female ratio was 1:4.8. Group 2 consisted of 51 patients aged 65.8±9.4 years; the male:female ratio was 1:1.125.

Conclusion: Based on the age tendency characteristics, Group 1 was called the involutional group and Group 2 the senile group. The age and gender distribution in the involutional group (Group 1) may be related mainly to climacteric disorders and suggested some influences of climacteric changes on the appearance of abnormal body sensation. On the other hand, the pathology in the senile group (Group 2) appeared to be associated with senile organic changes in addition to climacteric changes and sensory changes of skin and mucosal area during the involutional period.
Severe Sequelae of Group B Streptococcal (Streptococcus Agalactiae) Meningitis in an 82‐year‐old Man
Authors: Fujihara Kazuo , Fujioka Yasuhiro , Ohta Michiya , Itoyama Yasuto
Published: August 2007

Abstract: Group B Streptococcal (GBS) meningitis is rare in adults, and only 2 cases have been reported in Japan. Here we report GBS meningitis in an 82‐year‐old man. The patient with a history of colon cancer developed a high fever and severe headache, and was taken to our hospital several hours later. On admission he was semi‐comatose, light and corneal reflexes were normal, his neck was only mildly stiff. He was then on a respirator due to status epilepticus. Cerebrospinal fluid examination demonstrated marked pleocytoisis (46,2507/μ1, mostly polymorphonuclear cells) and GBS. With intensive care and antibiotic therapy, he regained consciousness 10 days later. However, he suffered severe dementia, hearing loss, limb muscle atrophy, and urinary retention in the chronic stage of the disease. Although survivors of adult GBS meningitis are reported to be free of severe neurologic sequelae, factors such as being the oldest patient among the reported cases, the premorbid malignancy and the marked inflammation were considered to be related to the severe neurologic sequelae in the present case.
A Case of Traumatic Brain Injury Developing Frontal Lobe Syndrome after a Long Incubation Period
Authors: Nagasawa Junya , Amano Naoji , Takahashi Miho , Kaneko Tomoki
Published: August 2007

Abstract: A 55‐year‐old man, who was a heavy drinker for about 30 years, had experienced a heavy blow on the right posterior temporal region on account of a traffic accident at the age of 16. He recovered without any sequelae. However, he began to make mistakes and had trouble with his job about 40 years after the accident. His symptoms and neuropsychological examination suggested frontal lobe syndrome. Cranial magnetic resonance imaging (MRI) showed that the frontal and temporal lobes seemed to be predominantly atrophic and that there was great enlargement of the lateral and third ventricles, and a post‐contusion lesion in the left frontal lobe. Brain single photon emission computer tomography (SPECT) demonstrated diffuse cerebral hypoperfusion. Cranial MRI suggested that the contusion was proportionate to contre coup injury resulting from the accident. We supposed that the extensive brain damage induced edema and ischemia soon after the accident. Consequently, the circulatory disturbance might have caused cerebral atrophy and enlargement of the ventricles. Since he was relatively young at the time of the accident, the plasticity of his brain compensated for the injury intensively, and obvious symptoms suggesting frontal lobe syndrome were latent for about 40 years after the accident. Continuous drinking may have induced recent dysfunction of the compensated brain. However, such severe atrophy and focal damaged lesion could not be solely accounted for by heavy alcohol consumption. On the other hand, organic changes due to aging and brain circulatory insufficiency caused by hypertension or hyperlipidemia may also disclose the cerebral dysfunction. His cranial MRI and SPECT seemed not to be consistent with frontotemporal dementia. Furthermore, we considered that his case was also different from Alzheimer's disease and normal pressure hydrocephalus. However, it is necessary to follow up neuro‐imaging. Conclusively, he developed frontal lobe syndrome based on traumatic brain injury and induced by continuous drinking, aging, and brain circulatory insufficiency.
Auditory Event‐Related Potentials (P300) and Regional Cerebral Blood Flow in Elderly Depressed Patients
Authors: Harada Kazuyoshi , Sumi Noriaki , Fujimoto Osamu , Tada Kunitoshi , Nan‐no Hisashige , Nishimura Tsuyoshi , Takeda Masatoshi
Published: August 2007

Background:In order to evaluate the degree of impairment of cerebral function and the organic factors involved in elderly depressed patients, auditory event‐related potentials (ERP; P300) and N‐isopropyl‐p [123I] iodoamphetamine (123I‐IMP) single photon emission computed tomography (SPECT) were examined.

Methods:Three groups of patients, the depression (D) group, consisting of 23 cases where the magnetic resonance imaging (MRI) showed no abnormalities, the depression with silent cerebral infarction (D/SCI) group, consisting of 28 cases with silent cerebral infarction, and the post‐stroke depression (D/PS) group, consisting of 19 cases at over six months after onset of cerebral infarction where no abnormalities in intellectual function were seen, but neurological symptoms such as hemiplegia were present, and 27 healthy individuals were investigated. All of the patients fulfilled the ICD‐10 diagnostic criteria for depressive episode, and disease onset occurred when the patients were over 55 years. The ERP (P300) was recorded using a tone discrimination task. Regional cerebral blood flow (rCBF) was measured by 123I‐IMP SPECT, and the relative rCBF of each region of interest was evaluated by comparison with the mean cerebellar rCBF. In addition, the mean cerebral blood flow (MCBF) in the cerebral cortex was assessed.

Results:The D group included many cases in which the P300 peak latency was relatively short and the MCBF was stable, relative to the other two groups. In the D/PS group, there were many cases where the P300 peak latency was prolonged and the MCBF was reduced. In the D/SCI group, many differences in the results from both indicators existed among individual cases, and no fixed trend was identified.

Conclusion: From the perspective of determining therapeutic tactics for elderly depressed patients and forecasting prognosis, it is important to review in detail, on an individual basis, components such as higher brain functions including cognitive functions, cerebral circulatory dynamics, and psychological/environmental factors. We believe that it is useful to evaluate a combination of factors when making such a review, including diagnostic imaging such as MRI, ERP (P300), and rCBF.
Global Increase in Cortical Opioid Binding Potential with Aging: In Vivo Quantification with 11C diprenorphine PET
Authors: Uema Takeshi , Rakshi James S. , Ito Kengo , Nishikawa Takashi , Takeda Masatoshi , Brooks David J.
Published: August 2007

Background:Recent studies using positron emission tomography (PET) have shown an increase of μ‐opioid receptors with aging in the human brain. However, its physiological role and relationship between the other subtypes of opioid receptors is still obscure. We used a non‐selective radiotracer [11C]diprenorphine and PET to estimate the effects of aging on brain opioid binding.

Methods:Seventeen normal male subjects were studied. Their ages ranged from 27 to 65 years (mean; 46 years). The data was analysed with global and regional opioid activities on images reflecting binding potential (Bmax/Kd) using statistical parametric mapping (SPM).

Results:The main effect of age was shown in the global opioid binding potential (p=0.046). A post‐hoc test revealed that the binding potentials began to increase abruptly in those aged 40 and above. SPM found that the binding activity of brain opioid receptors significantly increased with age throughout the cerebral cortex except in the primary visual and sensory‐motor cortices where little specific binding occurs. There were no age‐related changes in subcortical structures except for a part of the putamen.

Conclusion:The increase of opioid binding activities with aging probably depends on the density of μ‐opioid receptors, not K‐ nor δ‐ opioid receptors in association cortices. The detailed distribution shown by SPM suggests that this phenomenon may not be due to compensatory up‐regulation by the decrease in the endogenous opioid. The Increase of cortical opioid binding may contribute to the pathophysiology of depression and high risk of suicide attempts with advancing age.
Psychogeriatric Research: A Conceptual Introduction to Aging and Geriatric Neuroscience
Authors: Cacabelos Ramón
Published: August 2007

Abstract: Psychogeriatrics (PG) is a multidisciplinary specialty in clinical neuroscience dealing with brain disorders in the elderly population. As any other biomedical field PG has to establish an educational and practical framework in epidemiology, etiopathogenesis, diagnosis, treatment, and social, ethical, and legal issues associated with brain aging and age‐related central nervous system disorders. Understanding the molecular basis of aging will help to characterize and differentiate the fundamentals of pathological aging and psychogeriatric ailments. Modern epidemiology of age‐related brain disorders have to incorporate novel diagnostic criteria, biological markers, and genetic epidemiology to its methodological armamentarium to avoid bias. Molecular genetics will help to conceptually redefine many psychogeriatric disorders depending upon its genetic component and those interacting environmental factors leading to the phenotypic expression of given diseases. Genetic testing for monogenic and complex/polygenic/multifactorials disorders has to be included in diagnostic protocols since approximately 60 to 80% of major psychogeriatric disorders are genetically driven. It is also important to distinguish mutational genetics from susceptibility genetics in order to establish novel therapeutic strategies and preventive programmes. Genomics, proteomics, and pharmacogenomics are novel fields from which PG can benefit in the areas of etiopathogenesis, diagnosis, and treatment. Drug development in PG requires updated regulations in developed countries. New pharmacological treatments for aging brain disorders are needed. Pharmacogenomics will become an optimal strategy for drug development, contributing to design a molecular psychopharmacology for the elderly, individualizing drug therapy, optimizing efficacy and safety, and reducing unnecessary costs.
Assessment of Competency to Contract for Care Insurance in Aichi Prefecture
Authors: Mizuno Yutaka , Endo Hidetoshi , Kakimoto Makoto , Imai Makoto , Shibayama Hiroto
Published: August 2007

Background: A nursing care insurance system went into effect in April 2000 in Japan. Under the new system, the user (person requiring care) enters a contract directly with the service provider. Hence a pertinent issue is whether or not the user has the decision‐making capacity to enter a contract (competency to contract) and the degree of that capacity. The aim of the present study was to gain an understanding of the competency to contract under the new system.

Methods: The subjects were elderly residents who entered a care insurance facility after April 2000. Ten institutions from among the care insurance facilities in Aichi Prefecture cooperated in this study. The study was sufficiently explained to the elderly residents and their families, and written informed consent was obtained from both. Respective municipalities were requested to allow access to the results of the nursing care certification process of the subjects, with their consent and the consent of their families. In addition, the care manager of the facility gave the residents a Mini‐Test that we had prepared to determine competency to contract.

Results: The results revealed that most subjects had little understanding of the care system, and surprisingly, that they were not in the care insurance facility of their own volition. The competency to contract in the dementia group was significantly lower than in the non‐dementia group.

Conclusion: It may be unreasonable to believe that all such people are competent to enter a contract, especially those with dementia. However, the results suggest that people with a mild care grade, even if they have dementia, may have such competency. Further study including psychiatric assessment and diagnosis of the capacity to contract is necessary.