bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimum viscous damper for connecting adjacent SDOF structures for harmonic and stationary white‐noise random excitations
Authors: Bhaskararao A. V. , Jangid R. S.
Published: September 2006

The dynamic behaviour of two adjacent single‐degree‐of‐freedom (SDOF) structures connected with a viscous damper is studied under base acceleration. The base acceleration is modelled as harmonic excitation as well as stationary white‐noise random process. The governing equations of motion of the connected system are derived and solved for relative displacement and absolute acceleration responses of connected structures. The response of structures is found to be reduced by connecting with a viscous damper having appropriate damping. For undamped SDOF structures, the closed‐form expressions for optimum damping of viscous damper for minimum steady state as well as minimum mean square relative displacement and absolute acceleration of either of the connected SDOF structures are derived. The optimum damper damping is found to be functions of mass and frequency ratio of two connected structures. Further, numerical results had indicated that the damping of the connected structures does not have noticeable effects on the optimum damper damping and the corresponding optimized response. This implies that the derived closed‐form expressions for optimum damper damping of undamped structures can also be used in practical applications for damped structures. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis and localization of abnormal partial discharge activity in generator units
Authors: Pemen A. J. M. , van der Laan P. C. T.
Published: September 2006

This paper describes methods to monitor partial discharges (PDs) of important power plant components, such as generator stator windings, generator circuit‐breaker, and step‐up transformer. Two methods have been evaluated under practical conditions, using various sensors: (i) time‐domain measurements followed by signal‐processing to discriminate between PDs and interference, and (ii) a tunable narrow‐bandwidth filter which can be tuned to a frequency where PDs are strong and interference is weak. For several generators, abnormal PD activity was observed. In all cases, the source of these PDs could be located, by means of the transit‐time between various sensors. Examples of identified abnormal discharge activity are: (i) discharge activity between phase separations of a statorwinding, (ii) sparking inside a step‐up transformer, and (iii) large PDs in a generator circuit‐breaker. Copyright © 2006 John Wiley & Sons, Ltd.
Two‐dimensional MHD solver by fluctuation splitting and dual time stepping
Authors: Balcı Şölen , Aslan Necdet
Published: September 2006

Numerical solutions of 2D magneto‐hydrodynamic (MHD) equations by means of a fluctuation splitting (FS) scheme (with a new wave model and dual time stepping technique) is presented. The FS scheme, essentially based on the model explained in Proceedings of the Tenth International Conference, vol. 10, Swansea, 21–25 July 1997; Godunov Symposium, University of Michigan, Ann Arbor, 1–2 May 1997; Physics Symposium, Alanya, Turkey, 27–31 October 1998; J. Comput. Phys. 1999; 153:437–466; Ph.D. Thesis, University of Marmara, Istanbul, Turkey, 2000), was extended to include gravitational source effects, limiters to limit oscillations, high order time accuracy through multistage Runge–Kutta steps, and a dual time stepping scheme to drive magnetic field divergence to zero during iterations. The numerical results show that with the new wave model called MHD‐B along with its embedded numerical dissipation, correct limiting viscosity solution has been recovered and that it can safely be used in order to investigate steady or time dependent magnetized or neutral compressible flows in two dimensions. Copyright © 2006 John Wiley & Sons, Ltd.
Vesicular transmitter release from astrocytes
Authors: Montana Vedrana , Malarkey Erik B. , Verderio Claudia , Matteoli Michela , Parpura Vladimir
Published: September 2006

Astrocytes can release a variety of transmitters, including glutamate and ATP, in response to stimuli that induce increases in intracellular Ca2+ levels. This release occurs via a regulated, exocytotic pathway. As evidence of this, astrocytes express protein components of the vesicular secretory apparatus, including synaptobrevin 2, syntaxin, and SNAP‐23. Additionally, astrocytes possess vesicular organelles, the essential morphological elements required for regulated Ca2+‐dependent transmitter release. The location of specific exocytotic sites on these cells, however, remains to be unequivocally determined. © 2006 Wiley‐Liss, Inc.
Calcium signaling in invertebrate glial cells
Authors: Lohr Christian , Deitmer Joachim W.
Published: September 2006

Calcium signaling studies in invertebrate glial cells have been performed mainly in the nervous systems of the medicinal leech (Hirudo medicinalis) and the sphinx moth Manduca sexta. The main advantages of studing glial cells in invertebrate nervous systems are the large size of invertebrate glial cells and their easy accessibility for optical and electrophysiological recordings. Glial cells in both insects and annelids express voltage‐gated calcium channels and, in the case of leech glial cells, calcium‐permeable neurotransmitter receptors, which allow calcium influx as one major source for cytosolic calcium transients. Calcium release from intracellular stores can be induced by metabotropic receptor activation in leech glial cells, but appears to play a minor role in calcium signaling. In glial cells of the antennal lobe of Manduca, voltage‐gated calcium signaling changes during postembryonic development and is essential for the migration of the glial cells, a key step in axon guidance and in stabilization of the glomerular structures that are characteristic of primary olfactory centers. © 2006 Wiley‐Liss, Inc.
Astrocyte calcium waves: What they are and what they do
Authors: Scemes Eliana , Giaume Christian
Published: September 2006

Several lines of evidence indicate that the elaborated calcium signals and the occurrence of calcium waves in astrocytes provide these cells with a specific form of excitability. The identification of the cellular and molecular steps involved in the triggering and transmission of Ca2+ waves between astrocytes resulted in the identification of two pathways mediating this form of intercellular communication. One of them involves the direct communication between the cytosols of two adjoining cells through gap junction channels, while the other depends upon the release of “gliotransmitters” that activates membrane receptors on neighboring cells. In this review we summarize evidence in favor of these two mechanisms of Ca2+ wave transmission and we discuss that they may not be mutually exclusive, but are likely to work in conjunction to coordinate the activity of a group of cells. To address a key question regarding the functional consequences following the passage of a Ca2+ wave, we list, in this review, some of the potential intracellular targets of these Ca2+ transients in astrocytes, and discuss the functional consequences of the activation of these targets for the interactions that astrocytes maintain with themselves and with other cellular partners, including those at the glial/vasculature interface and at perisynaptic sites where astrocytic processes tightly interact with neurons. © 2006 Wiley‐Liss, Inc.
Calcium signaling in Schwann cells at synaptic and extra‐synaptic sites: Active glial modulation of neuronal activity
Authors: Rousse Isabelle , Robitaille Richard
Published: September 2006

Glial cells are widely dispersed in the central nervous system (CNS) as well as in the peripheral nervous system (PNS). In the PNS, perisynaptic Schwann cells (PSCs) are the glial cells associated with the pre‐ and postsynaptic elements of the neuromuscular junction (NMJ). They, as other glial cells of the CNS, respond to high‐frequency motor nerve stimulation with an increase in intracellular Ca2+. In addition to detecting and responding to neurotransmission, PSCs are involved in short‐term plasticity events where they depress neurotransmission through G‐protein‐dependent mechanisms and potentiate synaptic activity via Ca2+‐dependent mechanisms. In this review, we will discuss evidence that outlines the role of PSCs in short‐ and long‐term modulation of synaptic activity. We will also emphasize present functional similarities and differences in PSC activation at different NMJs. The importance of glial‐neural interactions along myelinating axons will also be discussed. © 2006 Wiley‐Liss, Inc.
P2X7 receptors: Properties and relevance to CNS function
Authors: Duan Shumin , Neary Joseph T.
Published: September 2006

Among seven members of P2X ionotropic receptors activated by extracellular ATP, the P2X7 subtype is unique in that it can function as a cation channel, a nonselective pore, or even a signaling complex coupled with multiple downstream components. Several roles of P2X7 receptors have been described in CNS cells in the past decade, including release of cytokines and transmitters, modulation of presynaptic transmitter release, and activation of multiple signaling pathways. The finding that P2X7 pores may directly mediate efflux of cytosolic glutamate, GABA, and ATP in glial cells is particularly interesting, as it provides a novel mechanism of glial transmitter release that may play important roles not only in physiological intercellular communication but also in pathological neural injury. © 2006 Wiley‐Liss, Inc.
Functional role of calcium signals for microglial function
Authors: Färber Katrin , Kettenmann Helmut
Published: September 2006

In this review we summarize mechanisms of Ca2+ signaling in microglial cells and the impact of Ca2+ signaling and Ca2+ levels on microglial function. So far, Ca2+ signaling has been only characterized in cultured microglia and thus these data refer rather to activated microglia as observed in pathology when compared with the resting form found under physiological conditions. Purinergic receptors are the most prominently expressed ligand‐gated Ca2+‐permeable channels in microglia and control several microglial functions such as cytokine release in a Ca2+‐dependent fashion. A large variety of metabotropic receptors are linked to Ca2+ release from intracellular stores. Depletion of these intracellular stores triggers a capacitative Ca2+ entry. While microglia are already in an activated state in culture, they can be further activated, for example, by exposure to bacterial endotoxin. This activation leads to a chronic increase of [Ca2+]i and this Ca2+ increase is a prerequisite for the release of nitric oxide and cytokines. Moreover, several factors (TNFα, IL‐1β, and IFN‐γ) regulate resting [Ca2+]i levels. © 2006 Wiley‐Liss, Inc.
Neurotransmitter‐mediated calcium signalling in oligodendrocyte physiology and pathology
Authors: Butt Arthur M.
Published: September 2006

The function of oligodendrocytes is to myelinate CNS axons. Oligodendrocytes and the axons they myelinate are functional units, and neurotransmitters released by axons can influence all stages of oligodendrocyte development via calcium dependent mechanisms. Some of the clearest functional evidence is for adenosine, ATP, and glutamate, which are released by electrically active axons and regulate the migration and proliferation of oligodendrocyte progenitor cells and their differentiation into myelinating oligodendrocytes. Glutamate and ATP, released by both axons and astrocytes, continue to mediate Ca2+ signaling in mature oligodendrocytes, acting via AMPA and NMDA glutamate receptors, and heterogeneous P2X and P2Y purinoceptors. Physiological signalling between axons, astrocytes, and oligodendrocytes is likely to play an important role in myelin maintenance throughout life. Significantly, ATP‐ and glutamate‐mediated Ca2+ signaling are also major components of oligodendrocyte and myelin damage in numerous pathologies, most notably ischemia, injury, periventricular leukomalacia, and multiple sclerosis. In addition, NG2‐expressing glia (synantocytes) in the adult CNS are highly reactive cells that respond rapidly to any CNS insult by a characteristic gliosis, and are able to regenerate oligodendrocytes and possibly neurons. Glutamate and ATP released by neurons and astrocytes evoke Ca2+ signaling in NG2‐glia (synantocytes), and it is proposed these regulate their differentiation capacity and response to injury. In summary, clear roles have been demonstrated for neurotransmitter‐mediated Ca2+ signaling in oligodendrocyte development and pathology. A key issue for future studies is to determine the physiological roles of neurotransmitters in mature oligodendrocytes and NG2‐glia (synantocytes). © 2006 Wiley‐Liss, Inc.
Functional connexin “hemichannels”: A critical appraisal
Authors: Spray David C. , Ye Zu‐Cheng , Ransom Bruce R.
Published: September 2006

“Hemichannels” are defined as the halves of gap junction channels (also termed connexons) that are contributed by one cell; “hemichannels” are considered to be functional if they are open in nonjunctional membranes in the absence of pairing with partners from adjacent cells. Several recent reviews have summarized the blossoming literature regarding functional “hemichannels”, in some cases encyclopedically. However, most of these previous reviews have been written with the assumption that all data reporting “hemichannel” involvement really have studied phenomena in which connexons actually form the permeability or conductance pathway. In this review, we have taken a slightly different approach. We review the concept of “hemichannels”, summarize properties that might be expected of half gap junctions and evaluate the extent to which the properties of presumptive “hemichannels” match expectations. Then we consider functions attributed to hemichannels, provide an overview of other channel types that might fulfill similar roles and provide sets of criteria that might be applied to verify involvement of connexin hemichannels in cell and tissue function. One firm conclusion is reached. The study of hemichannels is technically challenging and fraught with opportunities for misinterpretation, so that future studies must apply rigorous standards for detection of hemichannel expression and function. At the same time there are reasons to expect surprises, including the possibility that some time honored techniques for studying gap junctions may prove unsuitable for detecting hemichannels. We advise hemichannel researchers to proceed with caution and an open mind. © 2006 Wiley‐Liss, Inc.
Validation of the Spanish version of the EURO‐D scale: an instrument for detecting depression in older people
Authors: Larraga Laura , Saz Pedro , Dewey Michael E. , Marcos Guillermo , Lobo Antonio
Published: September 2006

Objective

To standardize the EURO‐D scale as a method for detecting depression in Spanish older people.

Methods

In a first phase, a sample of 1080 community older people was assessed with the GMS‐AGECAT by lay interviewers. In a second phase, all the probable cases and a similar number of randomly selected probable non‐cases were assessed using DSM‐III‐R diagnosis by psychiatrists. To test reliability, internal consistency with the Cronbach alpha coefficient and test–retest reliability (Kappa value) were obtained. Validity, sensitivity and specificity, predictive values, Receiver Operating Characteristic (ROC) curve, and Specific Likelihood Ratios (SSLR) were calculated.

Results

A high internal consistency was obtained in both phases of the study (α = 0.75; α = 0.79, respectively). Test–retest reliability was acceptable (weighted kappa = 0.60). For the prediction of DSM‐III‐R diagnosis validity coefficients (cut‐off point 3/4) were: sensitivity 91.8%, specificity 76.6% and area under the ROC curve 0.92 [95% Confidence Intervals (0.89–0.95)]. Illiteracy and cognitive difficulties had a small negative effect on the performance of the scale.

Conclusions

The EURO‐D scale is a reliable and valid instrument for detecting probable cases of depression in older people in Spain. Illiteracy and cognitive difficulties should be considered when interpreting the results. Copyright © 2006 John Wiley & Sons, Ltd.
A systematic review of intervention studies about anxiety in caregivers of people with dementia
Authors: Cooper Claudia , Balamurali T. B. S. , Selwood Amber , Livingston Gill
Published: September 2006

Background

There is considerable literature on managing depression, burden and psychological morbidity in caregivers of people with dementia (CG). Anxiety has been a relatively neglected outcome measure but may require specific interventions.

Objective

To synthesise evidence regarding interventions that reduce anxiety in CGs.

Methods

Twenty‐four studies met our inclusion criteria. We rated the methodology of studies, and awarded grades of recommendation (GR) for each type of intervention according to Centre for Evidence Based Medicine guidelines, from A (highest level of evidence) to D.

Results

Anxiety level was the primary outcome measure in only one study and no studies were predicated on a power calculation for anxiety level. There was little evidence of efficacy for any intervention. The only RCT to report significantly reduced anxiety involved a CBT and relaxation‐based intervention specifically devised to treat anxiety, and there was preliminary evidence (no randomised controlled trials) that caregiver groups involving yoga and relaxation without CBT were effective. There was grade B evidence that behavioural management, exercise therapies and respite were ineffective.

Limitations

Many interventions were heterogeneous, so there is some overlap between groups. Lack of evidence of efficacy is not evidence of lack of efficacy.

Conclusions

CBT and other therapies developed primarily to target depression did not effectively treat anxiety. Good RCTs are needed to specifically target anxiety which might include relaxation techniques. Some of the interventions focussed on reducing contact with the care recipients but caregivers may want to cope with caring and preliminary evidence suggests strategies to help CGs manage caring demands may be more effective. Copyright © 2006 John Wiley & Sons, Ltd.
Specific symptomatic changes following donepezil treatment of Alzheimer's disease: a multi‐centre, primary care, open‐label study
Authors: Rockwood Kenneth , Black Sandra , Bedard Marc‐Andre , Tran Thang , Lussier Isabelle
Published: September 2006

Background

Standard measurement scales used in anti‐dementia trials may not capture symptomatic changes recognized by clinicians and caregivers. We studied a symptom checklist, completed separately by caregivers and by clinicians, to identify patterns of change associated with donepezil treatment.

Methods

In a multi‐centre, 6‐month, open‐label study of 101 primary care patients, changes in a 19‐symptom checklist were assessed in relation to changes in standardized scales of cognition, activities of daily living, behavior, and caregiver burden.

Results

Three symptoms were reported in more than 80% of patients by both clinicians and caregivers: problems in remembering, (97%), temporal orientation (89%), and repetitiveness (85%). Five others overlapped on each of the clinician and caregiver ‘top ten’, including cognitive activation, spatial orientation, leisure, attention, and apathy. Clinicians reported that symptoms did not improve in 38 patients, whereas there was some improvement in 43, and improvement in most symptoms in 20. Caregivers reported that symptoms did not improve in 55 patients, whereas 27 and 19 patients showed some and most symptoms improving respectively. Patients with the greatest symptomatic improvement also improved most on the ADAS‐Cog and the other standardized measures, whereas no improvement (or decline) in each standardized measure was observed in people whose symptoms worsened or did not improve.

Conclusion

A symptom checklist allowed clinically meaningful profiles to be identified, but revealed different estimates of response between clinicians and caregivers. Both agreed that improved executive function was the most common response. A symptom checklist can help translate between standard measures and everyday practice. Copyright © 2006 John Wiley & Sons, Ltd.
A randomized, double‐blind, placebo‐controlled trial of donepezil hydrochloride (Aricept) for reducing the incidence of postoperative delirium after elective total hip replacement
Authors: Sampson Elizabeth L. , Raven Peter R. , Ndhlovu Patricia N. , Vallance Aaron , Garlick Nicholas , Watts Julie , Blanchard Martin R. , Bruce Angela , Blizard Robert , Ritchie Craig W.
Published: September 2006

Objectives

This was a pilot, phase 2a study to assess methodological feasibility and the safety and efficacy of donepezil in preventing postoperative delirium after elective total hip replacement surgery in older people without pre‐existing dementia. The hypothesis was that donepezil would reduce the incidence of postoperative delirium.

Methods

A double blind, placebo controlled, parallel group randomized trial was undertaken. Patients were block randomized pre‐operatively to receive placebo or donepezil 5 mg immediately following surgery and every 24 h thereafter for a further three days. The main outcome was the incidence of delirium (using the Delirium Symptom Interview). The secondary outcome was length of hospital stay.

Results

Thirty‐three patients (mean age 67 years; 17 males, 16 females) completed the study (19 donepezil, 14 placebo). Donepezil was well tolerated with no serious adverse events. Postoperative delirium occurred in 21.2% of subjects. Donepezil did not significantly reduce the incidence of delirium. The unadjusted risk ratio (donepezil vs placebo) for delirium was 0.29 (95% CI = 0.06,1.30) (χ2[1] = 3.06; p = 0.08). Mean length of hospital stay was 9.9 days for the donepezil group vs 12.1 days in the placebo group; difference in means = −2.2 days (95% CI = −0.39,4.78) (t[31] = 1.73: p = 0.09).

Conclusions

The experimental paradigm was feasible and acceptable. Donepezil did not significantly reduce the incidence of delirium or length of hospital stay, however for both outcomes there was a consistent trend suggesting possible benefit. The sample size required for a definitive trial (99% power, alpha 0.05) would be 95 subjects per arm. Copyright © 2006 John Wiley & Sons, Ltd.
Is there a causal link between currency and debt crises?
Authors: Dreher Axel , Herz Bernhard , Karb Volker
Published: September 2006

Though currency and debt crises quite often occur simultaneously, the links between these two types of crises are not well understood. We review how currency and debt crises could be related due to common causes, contagion effects from one crisis to the other, and complementary budget financing aspects. In an empirical analysis based on a panel of 80 countries over the period 1975–2000, we first investigate the determinants of each crisis separately. Then we estimate links between both crises employing instrumental variables techniques. We find that, while there is a negative lagged influence of currency crises on debt crises, currency crises significantly increase the risk of contemporaneous debt crises and vice versa. Copyright © 2006 John Wiley & Sons, Ltd.
Extended evidence on the use of technical analysis in foreign exchange
Authors: Gehrig Thomas , Menkhoff Lukas
Published: September 2006

This work extends earlier survey studies on the use of technical analysis by considering flow analysis as a third form of information production. Moreover, the survey covers FX dealers and also the rising fund managers. Technical analysis has gained importance over time and is now the most equally spread kind of analysis. It has by far the greatest importance in FX dealing and is second in fund management. Charts are used for shorter‐term forecasting horizons while flows dominate at the shortest‐term and fundamentals at longer horizons. Preferred users of each kind of analysis exhibit different views about market frictions. Copyright © 2006 John Wiley & Sons, Ltd.
MS‐KIF18A, a kinesin, is associated with estrogen receptor
Authors: Luboshits G. , Benayahu D.
Published: September 2006

The study of MS‐KIF18A kinesin protein is focused on its cellular distribution and association with a cargo protein. Indirect immunofluorescence (IF) analyzed the intracellular distribution of endogenous MS‐KIF18A and the transfected enhanced green fluorescence protein (eGFP)‐MS‐KIF18A in osteogenic cells. In both cases, the proteins were localized at the plasma membrane, cytosol, and nucleus. Bioinformatics analysis suggested interactions between MS‐KIF18A and estrogen receptor (ERα) which were further elucidated by immunoprecipitation (IP). We identified interaction between endogenous MS‐KIF18A with 66 and 46 kDa isoforms of ERα in MBA‐15 cells. Moreover, MS‐KIF18A and 66 kDa ERα complex has been demonstrated between ectopically expressed proteins in COS‐7 cells. We have shown that anti‐MS‐KIF18A antibody immunoprecipitated the ERα and pERK in cells challenged with 17β‐estrogen (17β‐E2). The hormone activation induced mitogen‐activated protein kinases (MAPK) pathway and increased p‐ERK. The activation was interfered when cells were pre‐treated with either ICI‐182,780 or MAPK inhibitor PD98059 prior the challenge with 17β‐E2 that resulted in a decrease in association between MS‐KIF18A and p‐ERK1/2. The obtained results suggest a role for the proteins in a non‐genomic response of MBA‐15 cells challenged with 17β‐E2. This study presents a novel interaction between MS‐KIF18A and ER that may have important physiological and pharmacological implications for estrogen action in various cells. J. Cell. Biochem. 100: 693–702, 2007. © 2006 Wiley‐Liss, Inc.
Matrix regulation of skeletal cell apoptosis III: Mechanism of ion pair‐induced apoptosis
Authors: Saunders Ray , Szymczyk Krysia H. , Shapiro Irving M. , Adams Christopher S.
Published: September 2006

Our previous work has demonstrated that while the Ca2+ and Pi ions acting in concert function as a potent osteoblast apoptogen, the underlying mechanisms by which it activates cell death is not known. We hypothesize that the ion pair causes release of Ca2+ from intracellular stores ([Ca2+]i); the increase in intracellular calcium prompts the mitochondria to uptake more calcium. This accumulation of calcium eventually results in the loss of mitochondrial membrane potential (MMP) and, subsequently, apoptosis. To test this hypothesis, we evaluated apoptosome formation in MC3T3‐E1 osteoblast‐like cells treated with the ion pair. Western blot analysis indicated migration of cytochrome‐c and Smac/DIABLO from mitochondria to the cytoplasm. Inhibition of either the electron transfer chain (with antimycin a and rotenone), or the activation of a MMP transition (with bongkrekic acid) inhibited apoptosis in a dose‐dependent manner. Pre‐treating osteoblasts with ruthenium red, a Ca2+ uniporter inhibitor of both mitochondria and the endoplasmic reticulum (ER), also completely abolished Ca2+.Pi‐induced apoptosis. Moreover, we showed that an increase in [Ca2+]i preceded the increase in MMP over the first 45 min of treatment; a mitochondrial membrane permeability transition was evident at 75 min. To determine the role of ER, Ca2+ stores in the generation of the apoptotic signal by the ion pair, cells were treated with several inhibitors. Apoptosis was inhibited when cells were treated with dantrolene, an inhibitor of ER ryanodine receptors, and 2‐aminodiphenylborate, an IP3 Ca2+ channel inhibitor, but not cyclopiazonic acid, an ER Ca2‐ATPase inhibitor. Together, these data demonstrate that Ca2+ Pi‐induced osteoblast apoptosis is characterized by the generation of an apoptosome and that Ca2+ release from ER stores may promote ion pair‐dependent cell death. J. Cell. Biochem. 100: 703–715, 2007. © 2006 Wiley‐Liss, Inc.
X‐ray fluorescence microprobe imaging in biology and medicine
Authors: Paunesku Tatjana , Vogt Stefan , Maser Jörg , Lai Barry , Woloschak Gayle
Published: September 2006

Characteristic X‐ray fluorescence is a technique that can be used to establish elemental concentrations for a large number of different chemical elements simultaneously in different locations in cell and tissue samples. Exposing the samples to an X‐ray beam is the basis of X‐ray fluorescence microscopy (XFM). This technique provides the excellent trace element sensitivity; and, due to the large penetration depth of hard X‐rays, an opportunity to image whole cells and quantify elements on a per cell basis. Moreover, because specimens prepared for XFM do not require sectioning, they can be investigated close to their natural, hydrated state with cryogenic approaches. Until several years ago, XFM was not widely available to bio‐medical communities, and rarely offered resolution better then several microns. This has changed drastically with the development of third‐generation synchrotrons. Recent examples of elemental imaging of cells and tissues show the maturation of XFM imaging technique into an elegant and informative way to gain insight into cellular processes. Future developments of XFM—building of new XFM facilities with higher resolution, higher sensitivity or higher throughput will further advance studies of native elemental makeup of cells and provide the biological community including the budding area of bionanotechnology with a tool perfectly suited to monitor the distribution of metals including nanovectors and measure the results of interactions between the nanovectors and living cells and tissues. J. Cell. Biochem. 99: 1489–1502, 2006. © 2006 Wiley‐Liss, Inc.
Survey of the year 2005: literature on applications of isothermal titration calorimetry
Authors: Ababou Adessamad , Ladbury John E.
Published: September 2006

Isothermal titration calorimetry (ITC) can provide a full thermodynamic characterization of an interaction. Its usage does not suffer from constraints of molecular size, shape or chemical constitution. Neither is there any need for chemical modification or attachment to solid support. This ease of use has made it an invaluable instrumental resource and led to its appearance in many laboratories. Despite this, the value of the thermodynamic parameterization has, only quite recently, become widely appreciated. Although our understanding of the correlation between thermodynamic data and structural details continues to be somewhat naïve, a large number of publications have begun to improve the situation. In this overview of the literature for 2005, we have attempted to highlight works of interest and novelty. Furthermore, we draw attention to those works which we feel have provided a route to better analysis and increased our ability to understand the meaning of thermodynamic change on binding. Copyright © 2006 John Wiley & Sons, Ltd.
An embeddedness framing of governance and opportunism: towards a cross‐nationally accommodating theory of agency—critique and extension
Authors: Zahra Shaker A.
Published: September 2006

Research on corporate governance has been increased in recent years, reflecting growing concern about the future of global capitalism. Much of this research has been under socialized. Lubatkin and colleagues attempt to address this serious shortcomings of past research. While making an important and informative contribution to research, I believe these authors overlook the questionable assumptions of agency models of governance. Lubatkin and colleagues also key issues resulting from the internationalization of corporate governance. Copyright © 2006 John Wiley & Sons, Ltd.
Historical instrumental climate data for Australia—quality and utility for palaeoclimatic studies
Authors: Nicholls Neville , Collins Dean , Trewin Blair , Hope Pandora
Published: September 2006

The quality and availability of climate data suitable for palaeoclimatic calibration and verification for the Australian region are discussed and documented. Details of the various datasets, including problems with the data, are presented. High‐quality datasets, where such problems are reduced or even eliminated, are discussed. Many climate datasets are now analysed onto grids, facilitating the preparation of regional‐average time series. Work is under way to produce such high‐quality, gridded datasets for a variety of hitherto unavailable climate data, including surface humidity, pan evaporation, wind, and cloud. An experiment suggests that only a relatively small number of palaeoclimatic time series could provide a useful estimate of long‐term changes in Australian annual average temperature. Copyright © 2006 John Wiley & Sons, Ltd.
Five centuries of climate change in Australia: the view from underground
Authors: Pollack Henry N. , Huang Shaopeng , Smerdon Jason E.
Published: September 2006

Fifty‐seven borehole temperature profiles from across Australia are analysed to reconstruct a ground surface temperature history for the past five centuries. The five‐hundred‐year reconstruction is characterised by a temperature increase of approximately 0.5 K, with most of the warming occurring in the 19th and 20th centuries. The 17th century was the coolest interval of the five‐century reconstruction. Comparison of the geothermal reconstruction to the Australian annual surface air temperature time series in their period of overlap shows excellent agreement. The full geothermal reconstruction also agrees well with the low‐frequency component of dendroclimatic reconstructions from Tasmania and New Zealand. The warming of Australia over the past five centuries is only about half that experienced by the continents of the Northern Hemisphere in the same time interval. Copyright © 2006 John Wiley & Sons, Ltd.
Time‐slice analysis of the Australian summer monsoon during the late Quaternary using the Fast Ocean Atmosphere Model
Authors: Marshall A. G. , Lynch A. H.
Published: September 2006

We use the Fast Ocean Atmosphere Model (FOAM) to investigate the variation in the Australian summer monsoon over the last 55 000 years. A synthesis of palaeoenvironmental observations is used to constrain the model for six time slices: 55, 35, 21, 11, 6 and 0 ka. Both inter‐hemispheric forcing and the seasonal timing of local insolation changes play key, and interacting, roles on the evolution and intensity of the monsoon.

During the onset to the monsoon, a heat low develops to the west of Australia over the Indian Ocean in all time slices, but with varying strengths. Divergent outflow from Asia converges with the cyclonic flow to bring increased rainfall to northern Australia and the maritime continent. The relative importance of a low pressure ‘pull’ and the high pressure ‘push’ varies according to the strength of the pressure anomalies. Only in the middle Holocene is the low pressure ‘pull’ the dominant forcing mechanism. At 21 ka, the climate shift to colder mean temperatures determines the large‐scale dynamics of the monsoon.

The general picture that emerges from these results is consistent with available palaeodata but highlights the importance of a broad regional perspective to ascribe the driving mechanisms at different times. Copyright © 2006 John Wiley & Sons, Ltd.
Reconstructing El Niño–Southern Oscillation (ENSO) from high‐resolution palaeoarchives
Authors: Gergis Joëlle , Braganza Karl , Fowler Anthony , Mooney Scott , Risbey James
Published: September 2006

El Niño–Southern Oscillation (ENSO) is one of the most important coupled ocean–atmospheric phenomena to cause global climate variability on interannual timescales. Efforts to understand recent, apparently anomalous ENSO behaviour are hampered by the phenomenon's unstable (non‐stationary) nature and the limitations inherent in palaeoclimate records. In this paper, the complexities associated with isolating ENSO signals in observational and palaeoclimate records are reviewed. The utility and limitations of high‐resolution (tree‐ring, coral, speleothems, ice and documentary) proxy data for ENSO reconstruction are discussed. To overcome the regional biases contained within each palaeoclimatic source, it is necessary to compare complementary signals derived from multiple proxy climate records. To date, there have been limited attempts to reconstruct large‐scale ENSO using these ‘multiproxy’ methodologies. A critique of the complexities associated with previous approaches of reconstructing discrete ENSO events and atmospheric/oceanic indices is provided. Abundant potential remains to better characterise teleconnection patterns, propagation signatures and non‐stationary features of large‐scale ENSO behaviour. If key uncertainties in ENSO dynamics (such as the response of extreme events to natural/human forcing) are to be adequately assessed, then complementary attempts must be made to model the historic synoptic conditions with apparent changes in reconstructed indices. Copyright © 2006 John Wiley & Sons, Ltd.
Integration of ice‐core, marine and terrestrial records for the Australian Last Glacial Maximum and Termination: a contribution from the OZ INTIMATE group
Authors: Turney C. S. M. , Haberle S. , Fink D. , Kershaw A. P. , Barbetti M. , Barrows T. T. , Black M. , Cohen T. J. , Corrège T. , Hesse P. P. , Hua Q. , Johnston R. , Morgan V. , Moss P. , Nanson G. , van Ommen T. , Rule S. , Williams N. J. , Zhao J.‐X. , D'Costa D. , Feng Y.‐X. , Gagan M. , Mooney S. , Xia Q.
Published: September 2006

The degree to which Southern Hemisphere climatic changes during the end of the last glacial period and early Holocene (30‐8 ka) were influenced or initiated by events occurring in the high latitudes of the Northern Hemisphere is a complex issue. There is conflicting evidence for the degree of hemispheric ‘teleconnection’ and an unresolved debate as to the principle forcing mechanism(s). The available hypotheses are difficult to test robustly, however, because the few detailed palaeoclimatic records in the Southern Hemisphere are widely dispersed and lack duplication. Here we present climatic and environmental reconstructions from across Australia, a key region of the Southern Hemisphere because of the range of environments it covers and the potentially important role regional atmospheric and oceanic controls play in global climate change. We identify a general scheme of events for the end of the last glacial period and early Holocene but a detailed reconstruction proved problematic. Significant progress in climate quantification and geochronological control is now urgently required to robustly investigate change through this period. Copyright © 2006 John Wiley & Sons, Ltd.
Development and testing of transfer functions for generating quantitative climatic estimates from Australian pollen data
Authors: Cook Ellyn J. , van der Kaars Sander
Published: September 2006

We review attempts to derive quantitative climatic estimates from Australian pollen data, including the climatic envelope, climatic indicator and modern analogue approaches, and outline the need to pursue alternatives for use as input to, or validation of, simulations by models of past, present and future climate patterns. To this end, we have constructed and tested modern pollen–climate transfer functions for mainland southeastern Australia and Tasmania using the existing southeastern Australian pollen database and for northern Australia using a new pollen database we are developing. After testing for statistical significance, 11 parameters were selected for mainland southeastern Australia, seven for Tasmania and six for northern Australia. The functions are based on weighted‐averaging partial least squares regression and their predictive ability evaluated against modern observational climate data using leave‐one‐out cross‐validation. Functions for summer, annual and winter rainfall and temperatures are most robust for southeastern Australia, while in Tasmania functions for minimum temperature of the coldest period, mean winter and mean annual temperature are the most reliable. In northern Australia, annual and summer rainfall and annual and summer moisture indexes are the strongest. The validation of all functions means all can be applied to Quaternary pollen records from these three areas with confidence. Copyright © 2006 John Wiley & Sons, Ltd.
Preparation of Core‐Sheath Composite Nanofibers by Emulsion Electrospinning
Authors: Xu Xiuling , Zhuang Xiuli , Chen Xuesi , Wang Xinri , Yang Lixin , Jing Xiabin
Published: September 2006

Summary: Uniform core‐sheath nanofibers are prepared by electrospinning a water‐in‐oil emulsion in which the aqueous phase consists of a poly(ethylene oxide) (PEO) solution in water and the oily phase is a chloroform solution of an amphiphilic poly(ethylene glycol)‐poly(L‐lactic acid) (PEG‐PLA) diblock copolymer. The obtained fibers are composed of a PEO core and a PEG‐PLA sheath with a sharp boundary in between. By adjusting the emulsion composition and the emulsification parameters, the overall fiber size and the relative diameters of the core and the sheath can be changed. A mechanism is proposed to explain the process of transformation from the emulsion to the core‐sheath fibers, i.e., the stretching and evaporation induced de‐emulsification. In principle, this process can be applied to other systems to prepare core‐sheath fibers in place of concentric electrospinning and it is especially suitable for fabricating composite nanofibers that contain water‐soluble drugs.

Schematic mechanism for the formation of core‐sheath composite fibers during emulsion electrospinning.

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Schematic mechanism for the formation of core‐sheath composite fibers during emulsion electrospinning.
Synthesis of Novel Star Shaped Poly(ε‐caprolactone) Utilizing Fullerene as the Molecular Core
Authors: Kai Weihua , Hua Lei , Zhao Li , Inoue Yoshio
Published: September 2006

Summary: The synthesis of star shaped poly(ε‐caprolactone) (PCL) with a fullerene molecular core (s‐PCLF) was successfully achieved by the ring‐opening polymerization of ε‐caprolactone with fullerenol as the initiator. Through NMR and GPC analysis, the average number of arms of PCL on each fullerene core was estimated to be 2–3.

Fullerenol (left) and PCL star polymer (right) in THF.

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Fullerenol (left) and PCL star polymer (right) in THF.
Surface Functionalization of Fe3O4 Magnetic Nanoparticles via RAFT‐Mediated Graft Polymerization
Authors: Wang Wen‐Cai , Neoh Koon‐Gee , Kang En‐Tang
Published: September 2006

Summary: Surface functionalization of Fe3O4 magnetic nanoparticles (MNP) via living radical graft polymerization with styrene and acrylic acid (AAc) in the reversible addition‐fragmentation chain transfer (RAFT)‐mediated process was reported. Peroxides and hydroperoxides generated on the surface of Fe3O4 nanoparticles via ozone pretreatment facilitated the thermally initiated graft polymerization in the RAFT‐mediated process. A comparison of the MNP before and after the RAFT‐mediated process was carried out using transmission electron microscopy (TEM) analysis, Fourier transform infrared (FTIR), and X‐ray photoelectron spectroscopy (XPS). Gel permeation chromatography (GPC) was used to determine the molecular weight of the free homopolymer in the reaction mixture. Well‐defined polymer chains were grown from the MNP surfaces to yield particles with a Fe3O4 core and a polymer outer layer. The resulting core–shell Fe3O4‐g‐polystyrene and Fe3O4‐g‐poly(acrylic acid) (PAAc) nanoparticles formed stable dispersions in the organic solvents for polystyrene (PS) and PAAc, respectively.

Schematic illustration of thermally induced graft polymerization of styrene and AAc with the ozone‐treated Fe3O4 MNP.

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Schematic illustration of thermally induced graft polymerization of styrene and AAc with the ozone‐treated Fe3O4 MNP.
Self‐Assembly of Two Agents in a Core‐Shell‐Corona Multicompartment Micelle Studied by Dissipative Particle Dynamics Simulations
Authors: Xia Jun , Zhong Chongli
Published: September 2006

Summary: Dissipative particle dynamics simulations are performed on the distributions of two agents in a core‐shell‐corona multicompartment micelle. The simulated results show that when the agents are weakly hydrophobic, their distributions in the multicompartment micelle are largely affected by the interactions between the agents and the blocks; while for strongly hydrophobic agents, the self‐assembly of solubilized species in the micelle is also affected largely by the interactions between the species. This work confirms that a multicompartment micelle can store two agents within separate nanoscopic compartments simultaneously, and shows that the distributions of the agents can be tailored easily by changing the interactions presented. This provides molecular‐level information that is useful for the future rational design of new micellar systems with tailored properties.

Simulated cross sections of the multicompartment micelles with strongly hydrophobic solubilized agents (the solvent and block A are omitted for clarity, block B is dark gray, block C is light gray, agent P is white, and agent Q is black).

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Simulated cross sections of the multicompartment micelles with strongly hydrophobic solubilized agents (the solvent and block A are omitted for clarity, block B is dark gray, block C is light gray, agent P is white, and agent Q is black).
Multiwalled Carbon Nanotubes Functionalized by Hyperbranched Poly(urea‐urethane)s by a One‐Pot Polycondensation
Authors: Yang Yingkui , Xie Xiaolin , Wu Jingao , Yang Zhifang , Wang Xiaotao , Mai Yiu‐Wing
Published: September 2006

Summary: Hyperbranched poly(urea‐urethane)‐functionalized multiwalled carbon nanotubes (MWNT‐HPUs) have been synthesized by a one‐pot polycondensation of tolylene 2,4‐diisocyanate and diethanolamine in the presence of MWNTs terminated with multiple hydroxy groups. FT‐IR, Raman, 1H NMR, and 13C NMR spectra reveal that the HPU trees are covalently grafted onto the MWNT surfaces. After a high density of HPU trees (83.5 wt.‐%) is attached to the MWNTs, core‐shell nanostructures with MWNTs as the core and the HPU trees as the shell are formed. A loose and uniform nanotube network can be observed by TEM, SEM, and AFM. The resulting MWNT‐HPUs are soluble in polar solvents such as dimethylformamide, dimethylacetamine, 1‐methyl‐2‐pyrrolidinone, and dimethyl sulfoxide.

Hyperbranched poly(urea‐urethane)s functionalized multiwalled carbon nanotubes.

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Hyperbranched poly(urea‐urethane)s functionalized multiwalled carbon nanotubes.
Molecular‐Complex Formation of Syndiotactic Polystyrene with Stable Radical Molecules
Authors: Kaneko Fumitoshi , Uda Yukihiro , Kajiwara Atsushi , Tanigaki Nobutaka
Published: September 2006

Summary: The formation of a molecular‐complex crystalline phase of syndiotactic polystyrene (sPS) that contains a stable nitroxide radical compound, 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl (TEMPO), is confirmed by IR and electron spin resonance (ESR) spectroscopy, X‐ray diffractometry, and thermogravimetric analysis. Through a guest exchange procedure assisted by a plasticizing agent, the original guest (chloroform) contained in the starting clathrate phase is completely replaced by TEMPO. Although the conformational regularity of the sPS helices in the resultant crystalline phase that contains TEMPO is similar to that in the starting clathrate phase, the host lattice expands in the 010 direction. The guest TEMPO molecules exhibit a significantly broadened ESR signal because of their highly concentrated state in the complex crystalline phase.

Thermogravimetric measurement of a powder sample of the sPS/TEMPO complex.

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Thermogravimetric measurement of a powder sample of the sPS/TEMPO complex.