bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic syndrome—a new world‐wide definition. A Consensus Statement from the International Diabetes Federation
Authors: Alberti K. G. M. M. , Zimmet P. , Shaw J.
Published: June 2006

Aims  To establish a unified working diagnostic tool for the metabolic syndrome (MetS) that is convenient to use in clinical practice and that can be used world‐wide so that data from different countries can be compared. An additional aim was to highlight areas where more research into the MetS is needed.

Participants  The International Diabetes Federation (IDF) convened a workshop held 12–14 May 2004 in London, UK. The 21 participants included experts in the fields of diabetes, public health, epidemiology, lipidology, genetics, metabolism, nutrition and cardiology. There were participants from each of the five continents as well as from the World Health Organization (WHO) and the National Cholesterol Education Program—Third Adult Treatment Panel (ATP III). The workshop was sponsored by an educational grant from AstraZeneca Pharmaceuticals.

Consensus process  The consensus statement emerged following detailed discussions at the IDF workshop. After the workshop, a writing group produced a consensus statement which was reviewed and approved by all participants.

Conclusions  The IDF has produced a new set of criteria for use both epidemiologically and in clinical practice world‐wide with the aim of identifying people with the MetS to clarify the nature of the syndrome and to focus therapeutic strategies to reduce the long‐term risk of cardiovascular disease. Guidance is included on how to compensate for differences in waist circumference and in regional adipose tissue distribution between different populations. The IDF has also produced recommendations for additional criteria that should be included when studying the MetS for research purposes. Finally, the IDF has identified areas where more studies are currently needed; these include research into the aetiology of the syndrome.
For Efficient Navigational Search, Humans Require Full Physical Movement, but Not a Rich Visual Scene
Authors: Ruddle Roy A. , Lessels Simon
Published: June 2006

During navigation, humans combine visual information from their surroundings with body-based information from the translational and rotational components of their movement. Theories of navigation focus on the role of visual and rotational body-based information, even though experimental evidence shows they are not sufficient for complex spatial tasks. To investigate the contribution of all three sources of information, we asked participants to search a computer-generated virtual room for targets. Participants were provided with only visual information or with visual information supplemented with body-based information for all movement (walk group) or rotational movement (rotate group). The walk group performed the task with near-perfect efficiency, irrespective of whether a rich or impoverished visual scene was provided. The visual-only and rotate groups were significantly less efficient and frequently searched parts of the room at least twice. These results suggest that full physical movement plays a critical role in navigational search, but only moderate visual detail is required.
Distinct Capacity Limits for Attention and Working Memory
Authors: Fougnie Daryl , Marois René
Published: June 2006

A hallmark of both visual attention and working memory is their severe capacity limit: People can attentively track only about four objects in a multiple object tracking (MOT) task and can hold only up to four objects in visual working memory (VWM). It has been proposed that attention underlies the capacity limit of VWM. We tested this hypothesis by determining the effect of varying the load of a MOT task performed during the retention interval of a VWM task and comparing the resulting dual-task costs with those observed when a VWM task was performed concurrently with another VWM task or with a verbal working memory task. Instead of supporting the view that the capacity limit of VWM is solely attention based, the results indicate that VWM capacity is set by the interaction of visuospatial attentional, central amodal, and local task-specific sources of processing.
The Transition from Excess Capacity to Strained Capacity in U.S. Hospitals
Authors: BAZZOLI GLORIA J. , BREWSTER LINDA R. , MAY JESSICA H. , KUO SYLVIA
Published: June 2006

After many years of concern about excess hospital capacity, a growing perception exists that the capacity of some hospitals now seems constrained. This article explores the reasons behind this changing perception, looking at the longitudinal data and in‐depth interviews for hospitals in four study sites monitored by the Community Tracking Study of the Center for Studying Health System Change. Notwithstanding the differences for individual hospitals, we observed that adjustments to the supply of hospital services tend to be slow and out of sync with changes in the demand for hospital services. Those hospitals reporting capacity problems are often teaching hospitals, located near previously closed facilities or in population growth areas. These findings suggest therefore that approaches to dealing with capacity problems might best focus on better matching individual hospitals' supply and demand adjustments.
“This Case Is Closed”: Family Caregivers and the Termination of Home Health Care Services for Stroke Patients
Authors: LEVINE CAROL , ALBERT STEVEN M. , HOKENSTAD ALENE , HALPER DEBORAH E. , HART ANDREA Y. , GOULD DAVID A.
Published: June 2006

Policies promoting home‐ and community‐based services and disease management models implicitly rely on family care, still the bedrock of long‐term and chronic care in the United States. The United Hospital Fund studied family caregivers of stroke and brain injury patients when home care cases were opened and closed and found that even with short‐term formal services, family caregivers provided three‐quarters of the care. Patients' mobility impairments and Medicaid eligibility were the main factors in determining the amount and duration of formal services. Between one‐third and one‐half of family caregivers reported being inadequately prepared for the case closing. At all stages, family caregivers expressed significant isolation, anxiety, and depression. Therefore, home care agency practice and public policies should provide better education, support, and services for family caregivers.
The establishment and dynamics of a recently established urban camp of flying foxes (Pteropus poliocephalus) outside their geographic range
Authors: Van Der Ree R. , McDonnell M. J. , Temby I. , Nelson J. , Whittingham E.
Published: June 2006

Grey‐headed flying foxes Pteropus poliocephalus (Megachiroptera: Pteropodidae), listed nationally in Australia as vulnerable, have been recorded infrequently in low numbers in Melbourne from the first record of the species in 1884 till the early 1980s. The number of individuals and duration of their visit to Melbourne increased dramatically in the early 1980s, with the first year‐round presence occurring in 1986 within the Royal Botanic Gardens, Melbourne. Anecdotal information suggests that the Melbourne colony has been continuously present since 1986; however, counts of roosting animals were sporadic between 1987 and 1993. Regular monthly counts that began in December 1993 confirm the continuous presence of the species in Melbourne from that date onwards. The growth of the size of the colony from 1994 onwards was exponential, with a peak in March 2003 (when counting ceased) at between 20 000 (static count) and 30 000 (flyout count) individuals. The number of P. poliocephalus within the colony fluctuated across the year, with a peak in summer/autumn (December–May) and a trough in winter/spring (July–October). The exact timing of the influx of animals varied slightly from year to year. The establishment of the permanent camp in urban Melbourne is a range expansion for the species.
Population spatial structuring on the feeding grounds in North Atlantic humpback whales (Megaptera novaeangliae)
Authors: Stevick P. T. , Allen J. , Clapham P. J. , Katona S. K. , Larsen F. , Lien J. , Mattila D. K. , Palsbøll P. J. , Sears R. , Sigurjónsson J. , Smith T. D. , Vikingsson G. , Øien N. , Hammond P. S.
Published: June 2006

Population spatial structuring among North Atlantic humpback whalesMegaptera novaeangliaeon the summer feeding grounds was investigated using movement patterns of identified individuals. We analysed the results from an intensive 2‐year ocean‐basin‐scale investigation resulting in 1658 individuals identified by natural markings and 751 individuals by genetic markers supplemented with data from a long‐term collaborative study with 3063 individuals identified by natural markings. Re‐sighting distances ranged from <1 km to >2200 km. The frequencies (F) of re‐sighting distances (D) observed in consecutive years were best modelled by an inverse allometric function (F=6631D−1.24,r2=0.984), reflecting high levels of site fidelity (median re‐sighting distance <40 km) with occasional long‐distance movement (5% of re‐sightings >550 km). The distribution of re‐sighting distances differed east and west of 45°W, with more long‐distance movement in the east. This difference is consistent with regional patterns of prey distribution and predictability. Four feeding aggregations were identified: the Gulf of Maine, eastern Canada, West Greenland and the eastern North Atlantic. There was an exchange rate of 0.98% between the western feeding aggregations. The prevalence of long‐distance movement in the east made delineation of possible additional feeding aggregations less clear. Limited exchange between sites separated by as little as tens of kilometres produced lower‐level structuring within all feeding aggregations. Regional and temporal differences in movement patterns reflected similar foraging responses to varying patterns of prey availability and predictability. A negative relationship was shown between relative abundance of herring and sand lance in the Gulf of Maine and humpback whale movement from the Gulf of Maine to eastern Canada.
Burrow architecture and burrowing dynamics of the endangered Namaqua dune mole rat (Bathyergus janetta) (Rodentia: Bathyergidae)
Authors: Herbst M. , Bennett N. C.
Published: June 2006

The Namaqua dune mole rat Bathyergus janetta is a solitary subterranean rodent that occurs in the arid and sandy regions of Namaqualand. The predictable winter rainfall and high diversity of geophytes, the predominant food resource, enables the mole rat to survive in this extreme environment. Burrowing and burrow system configuration were measured by observing mound production and the excavation of six mole rat burrow systems. A typical burrow system comprises nest chambers, food stores, defecation sites and bolt holes, which serve as a place of retreat when the animal is alarmed or threatened. Males tend to have linear‐shaped burrow systems, whereas the burrow systems of females are more reticulate. The linear nature of the male burrow system probably increases the home range used to search for potential mates. Burrow systems undergo constant excavation and re‐excavation within the home range. The average burrow length ranges from 71.2 to 165 m with a mean home range of 805.8±375.5 m2.
Phytoextraction of Cd and Zn with Salix viminalis in field trials
Authors: Hammer D. , Kayser A. , Keller C.
Published: June 2006

Abstract. Use of high biomass crops such as the willow Salix viminalis to extract metals for soil remediation has been proposed as an alternative to the low biomass‐producing hyperaccumulating plants. High yields compensate for the moderate heavy‐metal concentrations in the shoots of such species. We report the first long‐term trials using Salix viminalis to extract heavy metals from two contaminated soils, one calcareous (5 years) and one acidic (2 years). Total metals extracted by the plants were 170 g Cd ha−1 and 13.4 kg Zn ha−1 from the calcareous soil after 5 years, and 47 g Cd ha−1 and 14.5 kg Zn ha−1 from the acidic soil after 2 years; in the first year outputs were negligible. After 2 years, Salix had performed better on the acidic soil because of larger biomass production and higher metal concentrations in shoots. Addition of elemental sulphur to the soil did not yield any additional benefit in the long term, but application of an Fe chelate improved the biomass production. Cd and Zn concentrations were significantly higher in leaves than stems, highlighting the necessity to collect leaves as well as shoots. On both soils, concentration in shoots decreased with time, indicating a decrease in extraction efficiency.
Curtailment of muddy floods in the Sompting catchment, South Downs, West Sussex, southern England
Authors: Evans R. , Boardman J.
Published: June 2006

Abstract.Muddy floods due to runoff are a widespread problem on the South Downs of southern England and are associated with increased growing of autumn‐sown cereals over the last two decades. The 10.6 km2Sompting catchment has been monitored over the 12‐year period 1990/91–2001/02. A housing estate at the lower end of the catchment that was frequently inundated by muddy floods in the late 1980s and early 1990s has not been flooded since the winter of 1993/94, even during the heavy rainfall events of October and November 2000. This is a result of the ameliorative measures put in place in the early 1990s, primarily the reversion of some winter cereal fields to permanent grassland (set‐aside). Other land management changes helped, for example, some parts of the catchment were put down to short‐term grass leys and small dams were constructed to impound runoff. Flooding of the housing estate occurred when more than 30% of the catchment was covered by eroded fields, which contributed runoff to the valley floors leading down to the housing estate. The length of continuous down‐valley flow was greater in the early 1990s compared with later years. The introduction of grassland reduced the risk of flooding not only by reducing the area contributing to runoff, but also by stopping valley floor flows linking up. Such measures to alleviate runoff, erosion and flooding fit well with policies proposed in the recent report by the UK Policy Commission on the Future of Farming and Food.
A Rasch Model Analysis of DSM‐IV Alcohol Abuse and Dependence Items in the National Epidemiological Survey on Alcohol and Related Conditions
Authors: Kahler Christopher W. , Strong David R.
Published: June 2006

Background: Questions persist about the diagnoses of alcohol abuse and alcohol dependence as defined by Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition (DSM‐IV). These questions center around the performance of individual alcohol use disorder (AUD) criteria and the nature of items used to assess them. In this study, we conduct in‐depth analyses of interview items used to assess alcohol abuse and dependence.

Method: We conducted Rasch model analyses of responses to 33 items assessing alcohol abuse and dependence criteria in the National Epidemiological Survey on Alcohol and Related Conditions, a nationally representative sample of 34,550 participants. We also examined whether items performed differentially by gender, race/ethnicity, age, education, and time frame of assessment (i.e., past year vs lifetime).

Results: A single latent dimension explained the vast majority of shared variance among the items. Abuse symptoms were not of consistently lower severity than dependence symptoms, and some were consistently prone to differential functioning across subgroups. Items related to tolerance also functioned differentially across subgroups especially in the comparison of past‐year symptoms between young adults (ages 18–24) and older adults. Items differed widely in their empirically estimated severity, even when they were intended to assess the same DSM‐IV criterion.

Conclusions: The use of Rasch model analyses demonstrated the essential unidimensionality of AUD criteria and the lack of hierarchical ordering between abuse and dependence criteria, as well as potential sources of bias in the abuse diagnosis and the tolerance criterion. Results highlight that the prevalence and even the meaning of AUD criteria can differ substantially depending on the wording of items used to assess them. Implications for assessment of specific DSM criteria and for development of DSM‐V are discussed.
Sintering Analysis of Undoped and Cobalt Oxide Doped Ceria Solid Solutions
Authors: Jud Eva , Huwiler Christoph B. , Gauckler Ludwig J.
Published: June 2006

Pure and CoO1–x‐doped Ce0.8Gd0.2O1.9 (CGO) have been analyzed with constant heating rate dilatometry. Doping changes the grain boundary structure of CGO resulting in enhanced mass transport and in increased densification rates. Significant changes in activation energies have been detected. While pure CGO exhibits a significant amount of surface diffusion, cobalt oxide doping enhances grain boundary diffusion. The obtained activation energies are 4.70±0.32 eV for CGO and 6.24±0.32 eV for CoO1−x‐doped CGO. The higher activation energy of CoO1−x‐doped CGO is a result of the formation of intergranular films. It is suggested that sintering of CoO1−x‐doped CGO occurs by rearrangement and grain boundary diffusion whereas grain boundary and volume diffusion govern the densification of pure CGO.
Structure–Property Relationships of BaTi1−2yGayNbyO3 (0≤y≤0.35) Ceramics
Authors: Feteira Antonio , Sinclair Derek C. , Reaney Ian M. , Lanagan Michael T.
Published: June 2006

BaTi1−2yGayNbyO3 (BTGN) (0≤y≤0.35) powders were synthesized at 1300°C by the conventional solid‐state method. Room temperature x‐ray diffraction patterns for y≤0.025 and 0.05≤y≤0.30 can be indexed as the tetragonal (P4mm) and cubic (Pm

m) polymorphs of BaTiO3, respectively, whereas y=0.35 consists of a mixture of the cubic polymorph of BaTiO3 and an 8H hexagonal‐type perovskite (P63/mcm) isostructural with Ba8Ti3Nb4O24. Scanning electron microscopy shows the microstructures of BTGN ceramics (y≤0.30) sintered at 1500°C to consist of fine grains (1–3 μm) within a narrow grain size and shape distribution. Room temperature transmission electron microscopy for y≤0.08 reveals core–shell structures and (111) twins in some grains; however, their relative volume decreases with y. Energy dispersive spectroscopy reveals the cores to be Ga and Nb deficient with respect to y. For y>0.08 there is no evidence of core–shell structures, however, some grains have a high density of dislocations, consistent with chemical inhomogeneity. BTGN ceramics exhibit a diverse range of dielectric behavior in the temperature range 120–450 K and can be subdivided into two groups. 0.025≤y≤0.15 display modest ferroelectric relaxor‐type behavior, with high room temperature permittivity, ɛ25′, (>300 at 10 kHz), whereas 0.25≤y≤0.30 are temperature and frequency stable dielectrics with ɛ25′<100 that resonate at microwave frequencies with modest quality factors, Q×f, ∼3720 GHz (at ∼5 GHz) for y=0.30.
A Chemical Route to Large‐Scale Preparation of Spherical and Monodisperse Ni Powders
Authors: Choi Jae‐Young , Lee Yong‐Kyun , Yoon Seon‐Mi , Lee Hyun Chul , Kim Byung‐Ki , Kim Jong Min , Kim Kang‐Min , Lee Jong‐Heun
Published: June 2006

A facile chemical route to prepare a well‐defined Ni powder on a mass‐production scale without external heating was suggested. A highly concentrated Ni complex was formed between NiCl2 and N2H4 solution, and subsequent addition of NaOH solution triggered serial reactions from the Ni complex decomposition via Ni(OH)2 formation to the reduction of a Ni(OH)2 gel into well‐defined Ni spheres. The high temperature necessary for the reaction was attained not by external heating but by exothermic reactions such as complex formation and reduction. The preparation of monodisperse and spherical Ni powder was attributed to uniform distribution of the reducing agent (N2H4) within the Ni(OH)2 gel.
D4 Dopamine receptor genes of zebrafish and effects of the antipsychotic clozapine on larval swimming behaviour
Authors: Boehmler W. , Carr T. , Thisse C. , Thisse B. , Canfield V. A. , Levenson R.
Published: June 2006

Zebrafish, a model developmental genetic organism, is being increasingly used in behavioural studies. We have initiated studies designed to evaluate the response of zebrafish to antipsychotic drugs. This study focuses on characterization of zebrafish D4 dopamine receptors (D4Rs) and the response of larval zebrafish to the atypical antipsychotic clozapine. The D4R is of interest because of its high affinity for clozapine, while interest in clozapine stems from its effectiveness in reducing symptoms in acutely psychotic, treatment‐resistant schizophrenic patients. By mining the zebrafish genomic database, we identified three distinct D4R genes, drd4a, drd4b and drd4c, and generated full‐length open reading frames encoding each of the three D4Rs by reverse transcription–polymerase chain reaction. Gene mapping studies showed that each D4R gene mapped to a distinct chromosomal location in the zebrafish genome, and each gene exhibited a unique expression profile during embryogenesis. When administered to larval zebrafish, clozapine produced a rapid and profound effect on locomotor activity. The effect of clozapine was dose‐dependent, resulted in hypoactivity and was prevented by the D4‐selective agonist ABT‐724. Our data suggest that the inhibitory effect of clozapine on the locomotor activity of larval zebrafish may be mediated through D4Rs.
Neural Subtype Specification from Embryonic Stem Cells
Authors: Zhang Su‐Chun
Published: June 2006

One of the keys to using embryonic stem cells (ESCs) in brain research and potential application in neurological diseases is directed differentiation of neuronal and glial subtypes. This may be achieved by application of developmental principles in guiding cell lineage specification from naïve stem cells. Establishment of defined ESC differentiation models that recapitulate in vivo development, especially from human ESCs, will most likely provide a dynamic tool for dissecting molecular mechanisms underlying early embryonic development that is otherwise not readily obtainable. This is also a rational and realistic way of producing enriched populations of functional neurons and glia for pathological analyses as well as possible therapeutic applications.
Neural Stem Cell Systems: Diversities and Properties after Transplantation in Animal Models of Diseases
Authors: Conti Luciano , Reitano Erika , Cattaneo Elena
Published: June 2006

Currently available effective treatments of the diseased or damaged central nervous system (CNS) are restricted to a limited pharmacological relief of symptoms or those given to avoid further damage. Therefore the search is on for treatments that can restore function in the CNS. During recent years replacement of damaged neurons by cell transplantation is being enthusiastically explored as a potential treatment for many neurodegenerative diseases, stroke and traumatic brain injury. Several references in both scientific journals and popular newspapers concerning different types of cultured stem cells, potentially exploitable to treat pathological conditions of the brain, raise important questions pertinent to the fundamental and realistic differences between grafts of primary neural cells and the transplantation of in vitro expanded neural stem cells (NSCs). Our aim is to review the available information on the grafting of different NSC types into the adult rodent brain, focusing on critical aspects for the development of clinical therapies to replace damaged neurons.
The Pliocene Paradox (Mechanisms for a Permanent El Niño)
Authors: Fedorov A. V. , Dekens P. S. , McCarthy M. , Ravelo A. C. , deMenocal P. B. , Barreiro M. , Pacanowski R. C. , Philander S. G.
Published: June 2006

During the early Pliocene, 5 to 3 million years ago, globally averaged temperatures were substantially higher than they are today, even though the external factors that determine climate were essentially the same. In the tropics, El Niño was continual (or “permanent”) rather than intermittent. The appearance of northern continental glaciers, and of cold surface waters in oceanic upwelling zones in low latitudes (both coastal and equatorial), signaled the termination of those warm climate conditions and the end of permanent El Niño. This led to the amplification of obliquity (but not precession) cycles in equatorial sea surface temperatures and in global ice volume, with the former leading the latter by several thousand years. A possible explanation is that the gradual shoaling of the oceanic thermocline reached a threshold around 3 million years ago, when the winds started bringing cold waters to the surface in low latitudes. This introduced feedbacks involving ocean-atmosphere interactions that, along with ice-albedo feedbacks, amplified obliquity cycles. A future melting of glaciers, changes in the hydrological cycle, and a deepening of the thermocline could restore the warm conditions of the early Pliocene.
Near-Synchronous Interhemispheric Termination of the Last Glacial Maximum in Mid-Latitudes
Authors: Schaefer Joerg M. , Denton George H. , Barrell David J. A. , Ivy-Ochs Susan , Kubik Peter W. , Andersen Bjorn G. , Phillips Fred M. , Lowell Thomas V. , Schlüchter Christian
Published: June 2006

Isotopic records from polar ice cores imply globally asynchronous warming at the end of the last glaciation. However,
10
Be exposure dates show that large-scale retreat of mid-latitude Last Glacial Maximum glaciers commenced at about the same time in both hemispheres. The timing of retreat is consistent with the onset of temperature and atmospheric CO
2
increases in Antarctic ice cores. We suggest that a global trend of rising summer temperatures at the end of the Last Glacial Maximum was obscured in North Atlantic regions by hypercold winters associated with unusually extensive winter sea ice.
Transatlantic Abundance of the N
2
-Fixing Colonial Cyanobacterium
Trichodesmium
Authors: Davis Cabell S. , McGillicuddy Dennis J.
Published: June 2006

Colonial diazotrophic cyanobacteria of the genus
Trichodesmium
are thought to play a significant role in the input of new nitrogen to upper layers of the tropical and subtropical oceanic ecosystems that cover nearly half of Earth's surface. Here we describe results of a transatlantic survey in which a noninvasive underwater digital microscope (the video plankton recorder), was towed across the North Atlantic at 6 meters per second while undulating between the surface and 130 meters. Colony abundance had a basin-scale trend, a clear association with anticyclonic eddies, and was not affected by hurricane-forced mixing. Subsurface abundance was higher than previously reported, which has important implications for the global ocean nitrogen cycle.
Long-Term Potentiation of Neuron-Glia Synapses Mediated by Ca
2+
-Permeable AMPA Receptors
Authors: Ge Woo-Ping , Yang Xiu-Juan , Zhang Zhijun , Wang Hui-Kun , Shen Wanhua , Deng Qiu-Dong , Duan Shumin
Published: June 2006

Interactions between neurons and glial cells in the brain may serve important functions in the development, maintenance, and plasticity of neural circuits. Fast neuron-glia synaptic transmission has been found between hippocampal neurons and NG2 cells, a distinct population of macroglia-like cells widely distributed in the brain. We report that these neuron-glia synapses undergo activity-dependent modifications analogous to long-term potentiation (LTP) at excitatory synapses, a hallmark of neuronal plasticity. However, unlike the induction of LTP at many neuron-neuron synapses, both induction and expression of LTP at neuron-NG2 synapses involve Ca
2+
-permeable AMPA receptors on NG2 cells.
Converting Ceria Polyhedral Nanoparticles into Single-Crystal Nanospheres
Authors: Feng Xiangdong , Sayle Dean C. , Wang Zhong Lin , Paras M. Sharon , Santora Brian , Sutorik Anthony C. , Sayle Thi X. T. , Yang Yi , Ding Yong , Wang Xudong , Her Yie-Shein
Published: June 2006

Ceria nanoparticles are one of the key abrasive materials for chemical-mechanical planarization of advanced integrated circuits. However, ceria nanoparticles synthesized by existing techniques are irregularly faceted, and they scratch the silicon wafers and increase defect concentrations. We developed an approach for large-scale synthesis of single-crystal ceria nanospheres that can reduce the polishing defects by 80% and increase the silica removal rate by 50%, facilitating precise and reliable mass-manufacturing of chips for nanoelectronics. We doped the ceria system with titanium, using flame temperatures that facilitate crystallization of the ceria yet retain the titania in a molten state. In conjunction with molecular dynamics simulation, we show that under these conditions, the inner ceria core evolves in a single-crystal spherical shape without faceting, because throughout the crystallization it is completely encapsulated by a molten 1- to 2-nanometer shell of titania that, in liquid state, minimizes the surface energy. The principle demonstrated here could be applied to other oxide systems.
THE MANIFESTLY COVARIANT SOLITON SOLUTIONS ON NONCOMMUTATIVE ORBIFOLDS T2/Z6 AND T2/Z3
Authors: DENG HUI , HOU BO-YU , SHI KANG-JIE , YANG ZHAN-YING , YUE RUI-HONG , ZHAO LIU
Published: June 2006

In this paper, we construct a closed form of projectors on the integral noncommutative orbifold T2/Z6 in terms of elliptic functions by GHS (Gopakumar, Headrick and Spradlin) construction. Thereafter, we give a general solution of projectors on T2/Z6 and T2/Z3 with minimal trace and continuous reduced matrix M(k,q0). The projectors constructed by us possess symmetry and manifestly covariant forms under Z6 rotation. Since projectors correspond to the soliton solutions of field theory on the noncommutative orbifold, we thus present a series of corresponding manifestly covariant soliton solutions.
DYNAMICAL (SUPER)SYMMETRIES OF MONOPOLES AND VORTICES
Authors: HORVÁTHY P. A.
Published: June 2006

The dynamical (super)symmetries for various monopole systems are reviewed. For a Dirac monopole, non-smooth Runge–Lenz vector can exist; there is, however, a spectrum-generating conformal o(2,1) dynamical symmetry that extends into osp(1/1) or osp(1/2) for spin 1/2 particles. Self-dual 't Hooft–Polyakov-type monopoles admit an su(2/2) dynamical supersymmetry algebra, which allows us to reduce the fluctuation equation to the spin 0 case. For large r, the system reduces to a Dirac monopole plus a suitable inverse-square potential considered before by McIntosh and Cisneros, and by Zwanziger in the spin 0 case, and to the "dyon" of D'Hoker and Vinet for spin 1/2. The asymptotic system admits a Kepler-type dynamical symmetry as well as a "helicity-supersymmetry" analogous to the one Biedenharn found in the relativistic Kepler problem. Similar results hold for the Kaluza–Klein monopole of Gross–Perry–Sorkin. For the magnetic vortex, the N = 2 supersymmetry of the Pauli Hamiltonian in a static magnetic field in the plane combines with the o(2) × o(2,1) bosonic symmetry into an o(2) × osp(1/2) dynamical superalgebra.
DC CONDUCTION MECHANISMS IN AMORPHOUS THIN FILMS OF MIXED OXIDES In2O3–SnO2 SYSTEM DEPOSITED BY CO-EVAPORATION
Authors: ANWAR M. , SIDDIQI S. A. , GHAURI I. M.
Published: June 2006

A discussion of dc conduction mechanisms in thermally co-evaporated amorphous thin films of Al – In 2 O 3– SnO 2– Al structure is presented. Composition (in molar %), film thickness, substrate temperature, and post deposition annealing have profound effects on the electrical properties of the films. The effects of temperature on the I – V characteristics and electrical conductivity of Al – In 2 O 3– SnO 2– Al structure are also reported. The values of dielectric constants estimated by capacitance measurements suggest that high-field conduction mechanism is predominantly of Poole–Frenkel type. At low temperature and low field the electron hopping process dominates but at higher temperature the conduction takes place by transport in the extended states (free-band conduction). The transition from hopping to free band conduction is due to overlapping of localized levels and the free band. The increase in the formation of ionized donors with increase in temperature during electrical measurements indicates that electronic part of the conductivity is higher than the ionic part. The initial increase in conductivity with increase in Sn content in In 2 O 3 lattice is caused by the Sn atom substitution of In atom, giving out one extra electron. The decrease in electrical conductivity above the critical Sn content (10 mol % SnO 2) is caused by the defects formed by Sn atoms, which act as carrier traps rather than electron donors. The increase in electrical conductivity with film thickness is caused by the increase in free carriers density, which is generated by oxygen vacancy acting as two electrons donor. The increase in conductivity with substrate temperature and annealing is due either to the severe deficiency of oxygen, which deteriorates the film properties and reduces the mobility of the carriers or to the diffusion of Sn atoms from interstitial locations into the In cation sites and formation of indium species of lower valence state so that the In 3+ oxidation state may be changed to the In 2+ oxidation state.
VORTEX NUCLEATION IN ROTATING BOSE–EINSTEIN CONDENSATE: THE ROLE OF THE BOUNDARY CONDITION FOR THE ORDER PARAMETER
Authors: POGOSOV W. V. , MACHIDA K.
Published: June 2006

We study the problem of vortex nucleation in rotating two-dimensional Bose–Einstein condensate confined in a harmonic trap. We show that, within the Gross–Pitaevskii theory with the boundary condition of vanishing of the order parameter at infinity, topological defects nucleation occurs via the creation of vortex-antivortex pairs far from the cloud center, where the modulus of the order parameter is small. Then vortices move toward the center of the cloud and antivortices move in the opposite direction but never disappear. We also discuss the role of surface modes.
BEST CONSTANTS IN NORMS OF WICK PRODUCTS
Authors: STAN AUREL I.
Published: June 2006

Let [Formula: see text] be a Fock space and, for any non-negative integer k, let [Formula: see text] be the sum of all homogeneous chaos spaces of order at most k. For all non-negative integers m and n, the Wick product is a bounded bilinear operator from Γ (Hc)m × Γ (Hc)n into Γ (Hc)m +n with norm greater than or equal to [Formula: see text]. In the monograph1 S. Janson conjectured that this lower bound is exact. In this paper we prove this conjecture. In addition, we prove that a pair of nonzero vectors (ϕ, ψ)∈ Γ (Hc)m × Γ (Hc)n achieve this bound if and only if both vectors are multiples of the homogeneous products, i.e. ϕ =αu⊗m, ψ =βu⊗n, with u, v∈ Hc and α, β ∈ ℂ.
On the Concept and Types of Knowledge
Authors: Lee Chu Keong , Foo Schubert , Goh Dion
Published: June 2006

Knowledge is a concept that has gained importance in recent years because of the interest in knowledge management. One of the critical steps before embarking on any knowledge management initiative is to understand the concept of knowledge, so as to be able to identify the sources of knowledge in the organisation and to answer fundamental questions that will guide the design of knowledge management initiatives. Unfortunately, many practitioners rush headlong to roll out knowledge management in their organisations either without giving the object of management, i.e., knowledge, some thought, or with a narrow and parochial notion of knowledge. The objective of this article is to survey the concept of knowledge as seen from the perspective of scholars from various disciplines and to highlight the general and specialised typologies of knowledge. Only with a conceptual clarity of knowledge and an awareness of its various types can knowledge managers begin to craft effective knowledge management initiative for their organisation.
What Motivates Organisational Knowledge Transfer? Some Lessons from a UK-Based Multinational
Authors: Jasimuddin Sajjad M. , Connell N. A. D. , Klein Jonathan H.
Published: June 2006

The transfer of knowledge is an important task of contemporary organisations. In the knowledge-based economy, more and more organisations have increasingly recognised and encouraged the value of knowledge transfer. However, there is sometimes a tendency to horde knowledge, perhaps through fear of losing power or through uncertainty over job security. In this paper, we consider the motivators of knowledge transfer based on an empirical study carried out in part of a UK multinational, IBM Laboratories, in which the atmosphere appeared conducive to knowledge sharing, and knowledge transfer appeared voluntary and spontaneous. The paper questions why members of an organisation like IBM might be enthusiastic about the transfer of knowledge among themselves. The paper investigates the motivating factors that encourage the transfer of knowledge. A number of motivators underlying knowledge transfer are identified.
Mitochondrial reactive oxygen species and Ca2+ signaling
Authors: Camello-Almaraz Cristina , Gomez-Pinilla Pedro J. , Pozo Maria J. , Camello Pedro J.
Published: June 2006

Mitochondria are an important source of reactive oxygen species (ROS) formed as a side product of oxidative phosphorylation. The main sites of oxidant production are complex I and complex III, where electrons flowing from reduced substrates are occasionally transferred to oxygen to form superoxide anion and derived products. These highly reactive compounds have a well-known role in pathological states and in some cellular responses. However, although their link with Ca2+ is well studied in cell death, it has been hardly investigated in normal cytosolic calcium concentration ([Ca2+]i) signals. Several Ca2+ transport systems are modulated by oxidation. Oxidation increases the activity of inositol 1,4,5-trisphosphate and ryanodine receptors, the main channels releasing Ca2+ from intracellular stores in response to cellular stimulation. On the other hand, mitochondria are known to control [Ca2+]i signals by Ca2+ uptake and release during cytosolic calcium mobilization, specially in mitochondria situated close to Ca2+ release channels. Mitochondrial inhibitors modify calcium signals in numerous cell types, including oscillations evoked by physiological stimulus. Although these inhibitors reduce mitochondrial Ca2+ uptake, they also impair ROS production in several systems. In keeping with this effect, recent reports show that antioxidants or oxidant scavengers also inhibit physiological calcium signals. Furthermore, there is evidence that mitochondria generate ROS in response to cell stimulation, an effect suppressed by mitochondrial inhibitors that simultaneously block [Ca2+]i signals. Together, the data reviewed here indicate that Ca2+-mobilizing stimulus generates mitochondrial ROS, which, in turn, facilitate [Ca2+]i signals, a new aspect in the biology of mitochondria. Finally, the potential implications for biological modeling are discussed.
Assembly of mitochondrial cytochrome c-oxidase, a complicated and highly regulated cellular process
Authors: Fontanesi Flavia , Soto Ileana C. , Horn Darryl , Barrientos Antoni
Published: June 2006

Cytochrome c-oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, plays a key role in the regulation of aerobic production of energy. Biogenesis of eukaryotic COX involves the coordinated action of two genomes. Three mitochondrial DNA-encoded subunits form the catalytic core of the enzyme, which contains metal prosthetic groups. Another 10 subunits encoded in the nuclear DNA act as a protective shield surrounding the core. COX biogenesis requires the assistance of >20 additional nuclear-encoded factors acting at all levels of the process. Expression of the mitochondrial-encoded subunits, expression and import of the nuclear-encoded subunits, insertion of the structural subunits into the mitochondrial inner membrane, addition of prosthetic groups, assembly of the holoenzyme, further maturation to form a dimer, and additional assembly into supercomplexes are all tightly regulated processes in a nuclear-mitochondrial-coordinated fashion. Such regulation ensures the building of a highly efficient machine able to catalyze the safe transfer of electrons from cytochrome c to molecular oxygen and ultimately facilitate the aerobic production of ATP. In this review, we will focus on describing and analyzing the present knowledge about the different regulatory checkpoints in COX assembly and the dynamic relationships between the different factors involved in the process. We have used information mostly obtained from the suitable yeast model, but also from bacterial and animal systems, by means of large-scale genetic, molecular biology, and physiological approaches and by integrating information concerning individual elements into a cellular system network.
Sham feeding corn oil increases accumbens dopamine in the rat
Authors: Liang Nu-Chu , Hajnal Andras , Norgren Ralph
Published: June 2006

Both real and sham feeding of sucrose increase dopamine (DA) overflow in the nucleus accumbens (NAc). Fat is another constituent of foods that is inherently preferred by humans and rodents. We examined the affect of sham feeding corn oil in rats that were food and water deprived overnight. Rats were implanted with guide cannulas aimed at the NAc, as well as gastric fistulas. On alternate days, they were trained to sham lick 100% corn oil or distilled water (dH2O) for 20 min in the morning. Twenty-minute microdialysis samples were taken before, during, and after sham licking. DA and monoamines were analyzed by reverse-phase HPLC with coulometric detection. The results show that DA release in the NAc was significantly increased during sham licking of corn oil compared with the prior baseline (157.5 ± 18.8%, n = 12). During sham licking of dH2O, DA release in the NAc was not changed (93.0 ± 4.0%, n = 15). This experiment demonstrates that sham feeding of corn oil releases accumbens DA in a manner similar to ingestion of sucrose. Although both stimuli may have an olfactory component, sucrose is a gustatory, and 100% corn oil appears to be a trigeminal stimulus. Thus these data support the hypothesis that different sensory modalities produce reward using the same or closely related substrates in the forebrain.
Elevated hypothalamic orexin signaling, sensitivity to orexin A, and spontaneous physical activity in obesity-resistant rats
Authors: Teske J. A. , Levine A. S. , Kuskowski M. , Levine J. A. , Kotz C. M.
Published: June 2006

Selectively-bred obesity-resistant [diet resistant (DR)] rats weigh less than obesity-prone [diet-induced obese (DIO)] rats, despite comparable daily caloric intake, suggesting phenotypic energy expenditure differences. Human data suggest that obesity is maintained by reduced ambulatory or spontaneous physical activity (SPA). The neuropeptide orexin A robustly stimulates SPA. We hypothesized that DR rats have greater: 1) basal SPA, 2) orexin A-induced SPA, and 3) preproorexin, orexin 1 and 2 receptor (OX1R and OX2R) mRNA, compared with DIO rats. A group of age-matched out-bred Sprague-Dawley rats were used as additional controls for the behavioral studies. DIO, DR, and Sprague-Dawley rats with dorsal-rostral lateral hypothalamic (rLHa) cannulas were injected with orexin A (0, 31.25, 62.5, 125, 250, and 500 pmol/0.5 μl). SPA and food intake were measured for 2 h after injection. Preproorexin, OX1R and OX2R mRNA in the rLHa, and whole hypothalamus were measured by real-time RT-PCR. Orexin A significantly stimulated feeding in all rats. Orexin A-induced SPA was significantly greater in DR and Sprague-Dawley rats than in DIO rats. Two-mo-old DR rats had significantly greater rLHa OX1R and OX2R mRNA than DIO rats but comparable preproorexin levels. Eight-mo-old DR rats had elevated OX1R and OX2R mRNA compared with DIO rats, although this increase was significant for OX2R only at this age. Thus DR rats show elevated basal and orexin A-induced SPA associated with increased OX1R and OX2R gene expression, suggesting that differences in orexin A signaling through OX1R and OX2R may mediate DIO and DR phenotypes.
Intermedin (adrenomedullin-2) enhances cardiac contractile function via a protein kinase C- and protein kinase A-dependent pathway in murine ventricular myocytes
Authors: Dong Feng , Taylor Meghan M. , Samson Willis K. , Ren Jun
Published: June 2006

Intermedin (IMD), also called adrenomedullin-2, is a 47-amino acid peptide from the calcitonin gene-related peptide (CGRP)/adrenomedullin family of peptides. Recent studies suggest that IMD may participate in the regulation of cardiovascular function and fluid and electrolyte homeostasis. To evaluate the role of IMD on cardiomyocyte contractile function, electrically paced murine ventricular myocytes were acutely exposed to IMD, and the following indexes were determined: peak shortening (PS), time to PS, time-to-90% relengthening, and maximal velocity of shortening and relengthening. Intracellular Ca2+ was assessed using fura 2-AM fluorescent microscopy. Our results revealed that IMD (10 pM to 10 nM) significantly increased PS and maximal velocity of shortening and relengthening in ventricular myocytes, the maximal effect of which (∼46%) was somewhat comparable to those elicited by CGRP (1 nM) and adrenomedullin (100 nM). Exposure of IMD significantly shortened time-to-90% relengthening without affecting time to PS, similar to CGRP and adrenomedullin. IMD also enhanced intracellular Ca2+ release, with a maximal increase of ∼50%, and facilitated the intracellular Ca2+ decay rate. The IMD-induced effects were abolished by the protein kinase C inhibitor chelerythrine (1 μM), downregulation of protein kinase C using phorbol 12-myristate 13-acetate (1 μM), and the protein kinase A inhibitor H89 (1 μM). Our data suggest that IMD acutely augments cardiomyocyte contractile function through, at least in part, a protein kinase C- and protein kinase A-dependent mechanism.
Ordered Motor-Unit Firing Behavior in Acute Cerebellar Stroke
Authors: Sauvage Chloe , Manto Mario , Adam Alexander , Roark Rick , Jissendi Patrice , De Luca Carlo J.
Published: June 2006

It is known that at any given force level, the lower-threshold motor units generally fire at greater rates than the higher-threshold units during isometric tasks of extremity muscles. In addition to this hierarchical arrangement, firing rates of motor units fluctuate in unison with nearly no time delay; an observation that has led to the concept of common drive, a basic motoneuronal rule. Although it is established that the cerebellum plays a critical function in motor control, its role in the genesis, triggering, selection, and monitoring of motor-unit firing pattern discharges during isometric tasks is unknown. We applied an electromyographic (EMG) decomposition technique, known as precision decomposition, to accurately identify motor-unit firing times from the EMG signal recorded from the first dorsal interosseous muscle to unravel the features of motor-unit firings in three patients presenting a unilateral cerebellar stroke and exhibiting an acute cerebellar syndrome. We observed ataxic isometric force during visually guided abduction of the index finger on the affected side. However, the hierarchical response of individual motor units was spared. Furthermore, acute cerebellar ataxia was not associated with a loss of the common drive.