bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of a voltage‐dependent potassium channel protein (Kv3.1) in the embryonic development of the auditory system
Authors: Zhou Xiangning , Baier Christopher , Hossain Waheeda Amin , Goldenson Mark , Morest D. Kent
Published: August 2002

The present study traces the development of a voltage‐dependent potassium channel protein (Kv3.1) in the avian homologue of the cochlear nucleus, in the cochleovestibular ganglion, and in the otic epithelium from early developmental stages until near hatching. Immunohistochemistry with antibodies to the carboxy terminus (recognizing the Kv3.1b splice variant) and to the amino terminus (recognizing either form of Kv3.1) was used on Hamburger‐Hamilton‐staged chicken embryos. There were three periods in the relative levels of immunostaining in these regions. Early (E2–6), when precursor cells proliferate, migrate, and form axons, there was staining when using either antibody. In the middle period (E6–11), marked by hair cell differentiation, dendritic growth, and early synapse formation, staining levels decreased. In the late period (E11–19), when auditory function begins, staining increased rapidly, especially for Kv3.1b. Early Kv3.1 expression occurs in neuronal and hair cell precursors before they differentiate or function. Later, in the otic epithelium, a high level of Kv3.1 in cilia may precede or coincide with the onset of hair cell function. In neurons, some features of its localization correlate with axon outgrowth and synapse formation, others with the onset of neural activity and function. J. Neurosci. Res. 65:24–37, 2001. © 2001 Wiley‐Liss, Inc.
Transplants of cells genetically modified to express neurotrophin‐3 rescue axotomized Clarke's nucleus neurons after spinal cord hemisection in adult rats
Authors: Himes B. Timothy , Liu Yi , Solowska Joanna M. , Snyder Evan Y. , Fischer Itzhak , Tessler Alan
Published: August 2002

To test the idea that genetically engineered cells can rescue axotomized neurons, we transplanted fibroblasts and immortalized neural stem cells (NSCs) modified to express neurotrophic factors into the injured spinal cord. The neurotrophin‐3 (NT‐3) or nerve growth factor (NGF) transgene was introduced into these cells using recombinant retroviral vectors containing an internal ribosome entry site (IRES) sequence and the β‐galactosidase or alkaline phosphatase reporter gene. Bioassay confirmed biological activity of the secreted neurotrophic factors. Clarke's nucleus (CN) axons, which project to the rostral spinal cord and cerebellum, were cut unilaterally in adult rats by T8 hemisection. Rats received transplants of fibroblasts or NSCs genetically modified to express NT‐3 or NGF and a reporter gene, only a reporter gene, or no transplant. Two months postoperatively, grafted cells survived at the hemisection site. Grafted fibroblasts and NSCs expressed a reporter gene and immunoreactivity for the NGF or NT‐3 transgene. Rats receiving no transplant or a transplant expressing only a reporter gene showed a 30% loss of CN neurons in the L1 segment on the lesioned side. NGF‐expressing transplants produced partial rescue compared with hemisection alone. There was no significant neuron loss in rats receiving grafts of either fibroblasts or NSCs engineered to express NT‐3. We postulate that NT‐3 mediates survival of CN neurons through interaction with trkC receptors, which are expressed on CN neurons. These results support the idea that NT‐3 contributes to long‐term survival of axotomized CN neurons and show that genetically modified cells rescue axotomized neurons as efficiently as fetal CNS transplants. J. Neurosci. Res. 65:549–564, 2001. © 2001 Wiley‐Liss, Inc.
Hyperosmotic stress‐induced apoptosis and tau phosphorylation in human neuroblastoma cells
Authors: Stoothoff William H. , Johnson Gail V.W.
Published: August 2002

A characteristic hallmark of Alzheimer's disease brain is the presence of hyperphosphorylated tau; however, the mechanisms responsible for the aberrant tau phosphorylation are unknown. Recently, it has been shown that apoptotic‐like processes may be involved in some of the neuronal loss in Alzheimer's disease. In consideration of these findings, the relationship between tau phosphorylation and apoptosis was examined in human neuroblastoma SH‐SY5Y cells that were subjected to hyperosmotic stress. In this model caspase 3 activity, which served as an indicator of apoptosis, was increased by 30 min of osmotic stress and remained elevated through 4 hr. Hyperosmotic stress also resulted in a robust increase in tau phosphorylation at both Ser/Pro and non‐Ser/Pro sites. Phosphorylation of Ser262/356 (12E8) and Ser396/404 (PHF‐1) increased by 5 min and remained elevated for at least 1 hr. In contrast, phosphorylation within the Tau‐1 epitope did not increase (as evidenced by decreased immunoreactivity) until 30 min after treatment but remained elevated for a much greater period of time. Treatment with insulin‐like growth factor‐1 delayed but did not prevent apoptotic cell death induced by osmotic stress and attenuated the increase in phosphorylation at the Tau‐1 epitope. Li+, an inhibitor of glycogen synthase kinase 3β, had no effect on osmotic stress‐induced caspase activation, but reduced phosphorylation at the Tau‐1 epitope. Complete inhibition of osmotic stress‐induced caspase activation with DEVD‐CHO had no effect on the increases in tau phosphorylation. The results of these studies demonstrate that tau phosphorylation is increased at the specific epitopes during apoptosis. However, the changes in tau phosphorylation likely do not significantly impact the apoptotic process but rather occur concurrently as a result of inappropriate activation of specific protein kinases. Nonetheless, there is increasing evidence of a dysregulation of protein kinases that occurs in Alzheimer's disease brain that may be part of the events of apoptosis, which could contribute to aberrant increases in tau phosphorylation. J. Neurosci. Res. 65:573–582, 2001. © 2001 Wiley‐Liss, Inc.
Lovastatin treatment decreases mononuclear cell infiltration into the CNS of Lewis rats with experimental allergic encephalomyelitis
Authors: Stanislaus Romesh , Singh Avtar K. , Singh Inderjit
Published: August 2002

Mononuclear cell infiltration into the CNS and induction of inflammatory cytokines and iNOS in diseases like multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE) have been implicated in subsequent disease pathogenesis and progression. We report that Lovastatin treatment blocks the clinical disease and induction of inflammatory cytokines and iNOS in spinal cords of MBP induced EAE rats. A significant number of the infiltrating cells in CNS were ED1+ cells of monocyte/macrophage lineage. To understand the mechanism of efficacy of Lovastatin against EAE, we examined the effect of Lovastatin on the transmigration of mononuclear cells into EAE spinal cord. The data presented here documents that Lovastatin treatment attenuates the transmigration of mononuclear cells possibly by down regulating the expression of LFA‐1, a ligand for ICAM, in endothelial‐leukocyte interaction. These results indicate that Lovastatin treatment prevents infiltration by mononuclear cells into the CNS of rats induced for EAE, thereby lessening the histological changes and clinical signs and thus ameliorating the disease. These observations indicate that Lovastatin treatment may be of therapeutic value against inflammatory disease process associated with infiltration of activated mononuclear cells into the tissue. J. Neurosci. Res. 66:155–162, 2001. © 2001 Wiley‐Liss, Inc.
Channel activity of deamidated isoforms of prion protein fragment 106–126 in planar lipid bilayers
Authors: Kourie Joseph I. , Farrelly Peter V. , Henry Christine L.
Published: August 2002

Using the lipid bilayer technique, we have found that age‐related derivatives, PrP[106–126] (L‐Asp108) and PrP[106–126] (L‐iso‐Asp108), of the prion protein fragment 106–126 (PrP[106–126] (Asn108)) form heterogeneous ion channels. The deamidated isoforms, PrP[106–126] (L‐Asp108) and PrP[106–126] (L‐iso‐Asp108), showed no enhanced propensity to form heterogeneous channels compared with PrP[106–126] (Asn108). One of the PrP[106–126] (L‐Asp108)‐ and PrP[106–126] (L‐iso‐Asp108)‐formed channels had three kinetic modes. The current–voltage (I–V) relationship of this channel, which had a reversal potential, Erev, between –40 and –10 mV close to the equilibrium potential for K+ (EK –35 mV), exhibited a sigmoidal shape. The value of the maximal slope conductance (gmax) was 62.5 pS at positive potentials between 0 and 140 mV. The probability (Po) and the frequency (Fo) of the channel being open had inverted and bell‐shaped curves, respectively, with a peak at membrane potential (Vm) between –80 and +80 mV. The mean open and closed times (To and Tc) had inverted bell‐shaped curves. The biophysical properties of PrP[106–126] (L‐Asp108)‐ and PrP[106–126] (L‐iso‐Asp108)‐formed channels and their response to Cu2+ were similar to those of channels formed with PrP[106–126] (Asn108). Cu2+ shifted the kinetics of the channel from being in the open state to a “burst state” in which rapid channel activities were separated by long durations of inactivity. The action of Cu2+ on the open channel activity was both time‐dependent and voltage‐dependent. The fact that Cu2+ induced changes in the kinetics of this channel with no changes in the conductance of the channel indicated that Cu2+ binds at the mouth of the channel. Consistently with the hydrophilic and structural properties of PrP[106–126], the Cu2+‐induced changes in the kinetic parameters of this channel suggest that the Cu2+ binding site could be located at M109 and H111 of this prion fragment. J. Neurosci. Res. 66:214–220, 2001. © 2001 Wiley‐Liss, Inc.
Regional serotonin metabolism in the brain of transgenic mice lacking monoamine oxidase A
Authors: Popova Nina K. , Gilinsky Michael A. , Amstislavskaya Tamara G. , Morosova Ekaterina A. , Seif Isabelle , De Maeyer Edward
Published: August 2002

The effect of a lack of the gene encoding monoamine oxidase A (MAO A) in transgenic Tg8 mice on the activity of tryptophan hydroxylase (TPH), the rate‐limiting enzyme in serotonin (5‐HT) biosynthesis, and on the levels of 5‐HT and 5‐hydroxyindoleacetic acid (5‐HIAA) in the midbrain, hypothalamus, hippocampus, striatum, amygdala, and frontal cortex was studied. It was shown that mice with a genetic MAO A knockout differed from mice of the initial C3H/HeJ strain in having a higher level of 5‐HT and a lower level of its metabolite, 5‐HIAA, in all brain regions but the frontal cortex, where the changes were insignificant. Although the 5‐HIAA/5‐HT ratio in various brain regions differed considerably, the decrease of the 5‐HT oxidative deamination index in Tg8 mice was similar in different brain regions (to 41–45% of control values), with the exception of the frontal cortex, where the decrease of the 5‐HIAA/5‐HT was somewhat smaller (to 54%). The presence of the remaining 45% ± 1.9% of the control ratio value indicates rather effective oxidative deamination of 5‐HT in MAO A knockout mice and explains the lack of severe behavioral and pathological consequences in MAO A genetic deficiency. An increase of TPH activity in mice lacking MAO A was found in the frontal cortex, hippocampus, and amygdala. No significant changes were found in the striatum, hypothalamus, and midbrain. The data show an effect of the MAO A gene mutation on TPH and indicate a uniform decrease of 5‐HT catabolism in different brain regions except for the frontal cortex, which is somewhat more resistant to the lack of MAO A than other brain structures. J. Neurosci. Res. 66:423–427, 2001. © 2001 Wiley‐Liss, Inc.
Methamphetamine induces AP‐1 and NF‐κB binding and transactivation in human brain endothelial cells
Authors: Lee Yong Woo , Hennig Bernhard , Yao Jin , Toborek Michal
Published: August 2002

Cellular and molecular mechanisms of methamphetamine (METH)‐induced neurotoxicity may involve alterations of cellular redox status and induction of inflammatory genes in endothelial cells. To study these hypotheses, molecular signaling pathways of METH‐induced inflammatory responses via activation of redox‐sensitive transcription factors were investigated in human brain microvascular endothelial cells (HBMEC). A dose‐dependent depletion of total glutathione levels was detected in HBMEC exposed to METH. In addition, electrophoretic mobility shift assay (EMSA) showed significant increases in DNA binding activities of redox‐responsive transcription factors, AP‐1 and NF‐κB, in HBMEC treated with METH. METH‐mediated AP‐1 or NF‐κB activation was accompanied by induction of transactivation of AP‐1 or NF‐κB, as measured by dual luciferase assay using specific reporter plasmids. Because NF‐κB and AP‐1 are known to regulate expression of inflammatory genes, expression of the gene encoding for tumor necrosis factor‐α (TNF‐α) was also studied in METH‐treated HBMEC. A dose‐dependent overexpression of the TNF‐α gene was observed in HBMEC treated with METH. The importance of AP‐1 and NF‐κB in METH‐induced TNF‐α gene was confirmed in functional promoter studies using constructs of the TNF‐α promoter with mutated AP‐1 or NF‐κB sites. These results indicate that METH‐induced disturbances in cellular redox status and activation of AP‐1 and NF‐κB can play critical roles in the signaling pathways leading to upregulation of inflammatory genes in human brain endothelial cells. J. Neurosci. Res. 66:583–591, 2001. © 2001 Wiley‐Liss, Inc.
Job satisfaction: a meta‐analysis of stabilities
Authors: Dormann Christian , Zapf Dieter
Published: August 2002

Evidence suggesting that job satisfaction is caused by individual dispositions is reviewed, and stability coefficients for job satisfaction in previous studies are analysed with a meta‐analytic procedure. Previous longitudinal studies analysing job changer samples imply an upper limit estimate of 0.51 for direct dispositional influences on job satisfaction. A study of job changers considering the stability of working conditions suggests that this estimate has to be considerably corrected downwards. At present, it is concluded that it is more likely that dispositions indirectly affect job satisfaction via selection and self‐selection processes. Implications for job satisfaction as a tool for organizational assessment are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Indo‐Pacific relationships in terms of sea‐surface temperature variations
Authors: Sewell Richard D. , Landman Willem A.
Published: August 2002

In the last decade, a great deal of attention has been paid to the irregular interannual oscillation, known to the acronym writers as ENSO, or El Niño–Southern Oscillation. Algorithms have been developed which model the interaction between the ocean and the atmosphere, and because of the dependency of such modelling on the state of the oceans, various attempts have been made to predict the sea‐surface temperature (SST) anomalies and, further, to understand the relationship between the oceans and their role in the global propagation of the ENSO signal. To this end, a statistical study, using singular value decomposition (SVD), has been made of the relationship between the SSTs of the Pacific and Indian Oceans in the last 4 decades and, in particular, the changes which have taken place, especially in the Indian Ocean. The point of using SVD is that it enables the user to compare the Pacific and Indian Oceans as two separate entities with different dimensions, not one as an adjunct of the other. For the purpose of this analysis, it is assumed that the two oceans are distinct and have separate characteristics. A simple EOF analysis treating the two oceans as one tropical system, for example, would not accomplish this objective. While SVD analyses in meteorology and climatology have mainly been applied to two different meteorological parameters, for example SST and sea level pressure, in the same area, there is no valid reason why SVD should not be applied to the same (or different) parameter(s) in different regions. Although the Indian and Pacific Oceans are of different dimensions, SVD does not weight the result in favour of either the smaller or the larger of the two. SVD is a statistical tool which gives results comparable with canonical correlation analysis, though several authors warn against its indiscriminate use. It is found that the Indian Ocean SSTs have a strong association with Pacific Ocean SSTs, particularly when the Indian Ocean lags the Pacific Ocean by one season in mid‐summer. It is also found that there is a distinct change in the SST patterns in the equatorial Indian Ocean in the second half (1977–1996) of the period under study. Copyright © 2001 Royal Meteorological Society
The cause of warming over Norway in the ECHAM4/OPYC3 GHG integration
Authors: Benestad Rasmus E.
Published: August 2002

The cause of warming over Norway in a future global climate model (GCM) scenario is examined. Analysis of historical observations indicate that the observed long‐term temperature trends are not a result of systematic shifts in the North Atlantic Oscillation (NAO). The GCM prediction of past and future warming cannot be explained in terms of changes to the large‐scale atmospheric flow. The climate model results may suggest that the model has a seasonal bias with respect to the time of the year when the fastest warming occurs.

The NAO is associated with the warming after 1970, even though the 1860–1997 temperature trends do not appear to be connected with the NAO. An accurate description of the NAO is, therefore, critical for forecasting short‐term variability in the Norwegian winter climate and the results obtained here suggest that the model description of the NAO is generally good. Copyright © 2001 Royal Meteorological Society.
A conceptual model for understanding rainfall variability in the West African Sahel on interannual and interdecadal timescales
Authors: Nicholson S.E. , Grist J.P.
Published: August 2002

This article describes and validates a new conceptual model for understanding Sahel rainfall variability. This conceptual model provides a framework that can readily incorporate and synthesize the roles played by the oceans, the African landmass and local meteorological factors. The most important ‘local’ factors are the location of the African Easterly Jet (AEJ) and the associated shears. The position of the AEJ helps to distinguish between a ‘wet mode’ and a ‘dry mode’ in the Sahel, while other factors determine which of two spatial patterns prevail during years of the dry regime. We test the paradigm by contrasting selected circulation parameters for the years 1958–1967 (representing the wet mode) and 1968–1997 (representing the dry mode). In doing so, we have identified several changes in the general atmospheric circulation that have accompanied the shift to drier conditions. The AEJ is further southward and more intense, the Inter‐tropical Convergence Zone (ITCZ) is further south, the Tropical Easterly Jet (TEJ) is weaker, the equatorial westerlies are shallower and weaker, the southwesterly monsoon flow is weaker, and the relative humidity is lower (but not consistently so).

The results of this study suggest that the key factor controlling the occurrence of the ‘wet Sahel’ mode versus the ‘dry’ mode is the presence of deep, well‐developed equatorial westerlies. These displace the AEJ northward into Sahelian latitudes and increase the shear instabilities. The westerlies appear to be at least partially responsible for the well‐known association between a weaker AEJ and wetter conditions in the Sahel, because the thermal wind induced by the Sahara/Atlantic temperature gradient is imposed upon a westerly basic state. Since one of the strongest contrasts between the ‘wet Sahel’ and ‘dry Sahel’ modes is the strength of the TEJ, the TEJ probably also plays a pivotal role in rainfall variability. In the dry mode, the equatorial westerlies are poorly developed and the core of the AEJ lies well to the south of the Sahel. The dry mode consists of two basic spatial patterns, depending on whether the Guinea Coast Region is anomalously wet or dry (the well‐known dipole and no‐dipole patterns, respectively). Which occurs is determined by other factors acting to reduce the intensity of the rainbelt. One of the relevant factors appears to be sea‐surface temperatures (SSTs) in the Gulf of Guinea. Copyright © 2001 Royal Meteorological Society
Problems in evaluating regional and local trends in temperature: an example from eastern Colorado, USA
Authors: Pielke SR R. A. , Stohlgren T. , Schell L. , Parton W. , Doesken N. , Redmond K. , Moeny J. , McKee T. , Kittel T. G. F.
Published: August 2002

We evaluated long‐term trends in average maximum and minimum temperatures, threshold temperatures, and growing season in eastern Colorado, USA, to explore the potential shortcomings of many climate‐change studies that either: (1) generalize regional patterns from single stations, single seasons, or a few parameters over short duration from averaging dissimilar stations; or (2) generalize an average regional pattern from coarse‐scale general circulation models. Based on 11 weather stations, some trends were weakly regionally consistent with previous studies of night‐time temperature warming. Long‐term (80 + years) mean minimum temperatures increased significantly (P < 0.2) in about half the stations in winter, spring, and autumn and six stations had significant decreases in the number of days per year with temperatures ≤ − 17.8 °C (≤0 °F). However, spatial and temporal variation in the direction of change was enormous for all the other weather parameters tested, and, in the majority of tests, few stations showed significant trends (even at P < 0.2). In summer, four stations had significant increases and three stations had significant decreases in minimum temperatures, producing a strongly mixed regional signal. Trends in maximum temperature varied seasonally and geographically, as did trends in threshold temperature days ≥32.2 °C (≥90 °F) or days ≥37.8 °C (≥100 °F). There was evidence of a sub‐regional cooling in autumn's maximum temperatures, with five stations showing significant decreasing trends. There were many geographic anomalies where neighbouring weather stations differed greatly in the magnitude of change or where they had significant and opposite trends. We conclude that sub‐regional spatial and seasonal variation cannot be ignored when evaluating the direction and magnitude of climate change. It is unlikely that one or a few weather stations are representative of regional climate trends, and equally unlikely that regionally projected climate change from coarse‐scale general circulation models will accurately portray trends at sub‐regional scales. However, the assessment of a group of stations for consistent more qualitative trends (such as the number of days less than −17.8 °C, such as we found) provides a reasonably robust procedure to evaluate climate trends and variability. Copyright © 2002 Royal Meteorological Society
Daily wind gust speed probabilities over Switzerland according to three types of synoptic circulation
Authors: Jungo Patricia , Goyette Stéphane , Beniston Martin
Published: August 2002

The nowcasting and prediction of strong winds are still far from adequate, using either statistical or numerical modelling approaches. During the last decade, Switzerland has been struck by two extratropical storms, namely the February 1990 storm ‘Vivian’, and the December 1999 storm ‘Lothar’, that caused severe damage to infrastructure and to forests. Although numerical weather prediction models captured in both cases the cyclone tracks on the synoptic scale, the severity of local gusts was not properly predicted over the Swiss territory. To help predicting such phenomena, a combined approach to diagnose the wind gust speeds over Switzerland is described. The diagnostics aim at computing the probability of exceeding a gust speed based on the mean wind in relation to the prevailing synoptic weather type for a limited number of groups of climatological stations distributed throughout Switzerland. Based on 10 years of Swiss station observations, the computation of this probability uses an empirical gust factor that is a function of the daily gust speed, itself a function of the daily mean wind speed. For this period, each day has been categorized into three weather types according to the Schüepp classification. Principal component analysis and cluster analysis are performed in order to group climatological stations having similar characteristics in daily wind gust velocities. The results show that the gust factor provides an accurate method to compute the daily wind gust speeds at each Swiss climatological station for the given period. When combined with the three weather types and group of stations, the proposed diagnostics are an efficient method to predict the distribution of wind gust speeds. The gusts associated with the ‘Vivian’ and ‘Lothar’ storms are then diagnosed for each specific group where more than 85% of the stations responded similarly to their specific group members, which is highly satisfactory in this case. Copyright © 2002 Royal Meteorological Society
Intracellular sites of photodamage as a factor in apoptotic cell death
Authors: KESSEL D. , LUO Y.
Published: August 2002

The cytotoxic response to photodynamic therapy can involve apoptosis, necrosis or both. Using agents with known patterns of sub-cellular localization, we assessed different sites of photodamage as a determinant of cell death, using murine leukemia cells in vitro. Mitochondrial or mitochondrial + lysosomal photodamage led to a rapid apoptotic response, associated with the release of cytochrome c from mitochondria into the cytosol. This occurred immediately after irradiation of photosensitized cells. When photodamaged cells were warmed to 37 °C, there was a rapid apoptotic response. Lysosomal photodamage led to the immediate release of cathepsins and other proteolytic enzymes. During a subsequent incubation at 37 °C, there was a slow loss of the mitochondrial membrane potential, with cytochrome c appearing in the cytosol within 30 min. These effects derive from proteolytic effects of lysosomal enzymes on mitochondria. The apoptotic response to lysosomal photodamage was both slow and incomplete, with many non-viable cells not exhibiting apoptotic morphology. The latter result was correlated with photodamage to procaspase-3, an effect not observed when mitochondria were the predominant target for photodamage. Depending on the sub-cellular target, photodynamic therapy can either activate or inhibit critical elements of apoptosis.
Dimeric aggregates of five-coordinated methyl(phthalocyaninato)Rh(III): 1H NMR evidence for staggered and slipped cofacial dimers
Authors: CHEN M. J. , RATHKE J. W.
Published: August 2002

The 1 H NMR spectra of the five-coordinated rhodium phthalocyanine complex Me ( RPc ) Rh (III) (1, RPc = dianion of 1,4,8,11,15,18,22,25-octa-n-pentylphthalocyanine) in toluene indicate that it exists as a discrete monomer at low concentrations. The complex forms a dimer aggregate reversibly in the concentration range of 2.6–10.2 mM at -90 < T < 22 ° C . The dimerization constants at -60, -80, and -90 °C are 2.0 × 102, 5.7 × 102, and 1.0 × 103 M -1, respectively. In chloroform, aggregation of the complex occurs at ~0.3 mM, reflecting the lower solvating power of chloroform for this complex. The 1 H NMR spectra of the chloroform solutions indicate that at concentrations greater than 1.0 mM, two discrete dimers in the ratio of 87:13 are reversibly formed. The 1 H NMR spectra of the major isomer, 2a, suggest that it is the 45 °-staggered cofacial dimer, a dimer with a D4 d symmetry. The 1 H NMR spectra of the minor isomer, 2b, suggest that it is a slipped cofacial dimer with a C2 h symmetry, which is formed by slipping a ( RPc ) Rh plane of the eclipsed dimer (a D4 h dimer) along a line connecting two opposing meso nitrogens of ( RPc ) Rh . Interestingly, the solution conformation of 2b is similar to that of the basic stacking unit found in the crystal structure of 1.
Dinoflagellate cyst assemblages in surface sediments of the Laptev Sea region (Arctic Ocean) and their relationship to hydrographic conditions
Authors: Kunz‐Pirrung Martina
Published: August 2002

The occurrence and distribution of dinoflagellate cysts in surface sediments from the Laptev Sea shelf and the adjacent continental margin have been studied in relation to surface water conditions. Assemblages were interpreted by visual inspection and Q‐mode factor analysis. The inner Laptev shelf is a type‐area for polar environments because of the near absence of relatively warm waters from the Pacific or Atlantic oceans and an extensive seasonal sea‐ice cover. Assemblages are of low diversity and are dominated by the cold water taxon Islandinium minutum and related morphotypes. The common occurrence of distinctive polykrikoid cyst morphotypes is an indicator of polar environments. Furthermore, a strong supply of fresh water in summer influences the surface water conditions, and is a major factor controlling the occurrence and distribution of dinoflagellate cysts. The dinoflagellate cysts Nematosphaeropsis labyrinthus and Operculodinium centrocarpum are restricted to the continental margin, suggesting a relation to the inflow of relatively warm Atlantic waters along the Eurasian continental margin. An abundance maximum of Brigantedinium spp. at the shelf break is related to the mean position of the marginal ice zone. Copyright © 2001 John Wiley & Sons, Ltd.
Distribution of dinoflagellate cysts in the Canadian Arctic marine region
Authors: Mudie Peta J. , Rochon André
Published: August 2002

The Canadian Arctic is a major gateway for transport of freshwater from the Arctic Ocean to the North Atlantic. This region comprises the Beaufort Sea, the Canadian Arctic Archipelago (CAA) and northern sections of Baffin and Hudson bays. Subregional differences include major freshwater runoff to the Beaufort Sea and Hudson Bay, presence of Pacific and Atlantic Intermediate water in the west, and Atlantic Water in Baffin and Hudson bays. Principal component analysis of 50 core‐top samples shows four subregional dinoflagellate cyst assemblages. Outer Beaufort Shelf Assemblage I is co‐dominated by Operculodinium centrocarpum s.l. and Brigantedinium spp., with minor cysts of Pentapharsodinium dalei, Algidasphaeridium? minutum s.l. and cysts of Polykrikos spp. Assemblage II in the Canadian Arctic Archipelago is co‐dominated by Brigantedinium spp., A.? minutum s.l. and cysts of Polykrikos spp., including two Arctic morphotypes. Assemblage III in the North Water polynya exclusively comprises A.? minutum s.l. and Brigantedinium spp. Assemblage IV in Baffin Bay is dominated by O. centrocarpum s.l. and Spiniferites spp., with Brigantedinium spp. on the shelves. The ratio of gonyaulacoid to protoperidinioid cysts (G : P) generally decreases with increased sea‐ice cover, but it may also decrease in river plumes and in polynyas. Copyright © 2001 John Wiley & Sons, Ltd.
Raman spectroscopic characterization of Bombyx mori silk fibroin: Raman spectrum of Silk I
Authors: Monti P. , Taddei P. , Freddi G. , Asakura T. , Tsukada M.
Published: August 2002

This study focuses on the conformational characterization of differently processed Bombyx mori silk fibroin samples by Raman spectroscopy. The Raman spectra of silk fibroin film and liquid silk are discussed in comparison with those of the crystalline fractions of Bombyx mori silk fibroin (Cp, chymotryptic precipitate) with Silk I (Silk I‐Cp) and Silk II (Silk II‐Cp) structures. The complete 1800–200 cm−1 Raman spectrum of Silk I‐Cp is reported for the first time. The amide I and amide III modes were found to be scarcely suitable for the spectroscopic characterization of silk fibroin in the Silk I form in the presence of a random coil conformation. Raman marker bands for the Silk I form were identified in other spectral ranges at about 1415, 950, 930, 865, 260 and 230 cm−1. On the basis of the above findings, the comparison of the Raman spectra of film, liquid silk and Silk I‐Cp in the range 1000–800 cm−1 clearly indicates that in addition to random coil, both film and liquid silk contain local domains of Silk I structure; their amount is higher in liquid silk, as indicated by the relative intensity of the bands at about 950, 930 and 865 cm−1 and by the I1415/I1455 intensity ratio.

The assignments of the bands at about 1275 and 1107 cm−1 are also discussed. These bands were previously assigned to the presence of α‐helical conformation in Bombyx mori silk but, from the results reported, they should rather be attributed to the Silk I form. Copyright © 2001 John Wiley & Sons, Ltd.
Time‐resolved polarization‐sensitive measurements of the electric field in a sliding discharge by means of dc field‐induced coherent Raman scattering
Authors: Tskhai S. N. , Akimov D. A. , Mitko S. V. , Ochkin V. N. , Serdyuchenko A. Yu. , Sidorov‐Biryukov D. A. , Sinyaev D. V. , Zheltikov A. M.
Published: August 2002

We investigated the properties of the IR signal generated through coherent Raman scattering involving the Q(1) transition (v = 0, J = 1→v = 1, J = 1) of a hydrogen molecule in the presence of the quasi‐static electric field of the sliding discharge propagating along a ferrite surface in a hydrogen atmosphere. The results of time‐resolved polarization‐sensitive measurements performed on this signal were employed to determine the parameters of the electric field in the sliding discharge. These measurements showed, in particular, that the propagation of the discharge leader along the ferrite surface is accompanied by the rotation of the vector of the quasi‐static electric field. Copyright © 2001 John Wiley & Sons, Ltd.
An evolutionary concept of multilevel strategic change: the Shell case
Authors: Sachs Sybille , Ruehli Edwin
Published: August 2002

This paper contends that modern evolutionary concepts developed in different scientific fields can improve the understanding of a firm's strategic change in the new competitive realities.

The arguments and reflections are distilled into four propositions characterizing multilevel strategic change under the conditions of complexity and dynamics.

Theoretical points are illustrated with examples and statements by reference to Shell and show how the management of this firm influenced the strategic evolution.

Copyright © 2001 John Wiley & Sons, Ltd.
Company analysis: determining strategic capability
Authors: Hussey David
Published: August 2002

Assessing corporate strengths and weaknesses was seen as a critical step in much of the early literature on strategy, such as Ansoff (1965). In his thinking it was bound up with capability profiles, the search for synergy and the internal and external appraisals.

As the knowledge of strategic management has expanded and the methods and techniques available have increased, there has been a tendency to ignore the importance of analysing the organization.

Copyright © 2002 John Wiley & Sons, Ltd.
Correlation between antiradical activity and stability of betanine from Beta vulgaris L roots under different pH, temperature and light conditions
Authors: Pedreño M A , Escribano J
Published: August 2002

When the antiradical activity and stability of betanine were studied at pH values of 3.5 and 8.5 and temperatures of 25, 50 and 75 °C, the results showed that the antiradical activity was greater at acidic pH and lower at higher temperatures. At basic pH the activity of betanine correlated well with its stability at the three temperatures assayed, suggesting that the degradation products, betalamic acid (BA) and cyclo DOPA 5‐O‐β‐D‐glucoside (CDG), did not contribute to this activity under the experimental conditions used. However, at acidic pH the degradation product, CDG, did seem to contribute to the antiradical activity. Furthermore, at pH 3.5, betanine stability was so great that light conditions had no effect on the antiradical activity. At basic pH, too, light had no effect on betanine activity owing to the high instability of the pigment.

© 2001 Society of Chemical Industry
Changes in colour and phenolic composition during the early stages of maturation of port in wood, stainless steel and glass
Authors: Ho Peter , Silva Maria da Conceição M , Hogg Timothy A
Published: August 2002

Differences in colour and phenolic composition during the maturation of port in oak wood, stainless steel and glass were examined for a period of 311 days at 18 °C. Principal component analysis (PCA) was used in variable selection, data reduction and data analysis. Nine out of 13 colour and phenolic variables were heavily loaded on PC1 (76.1% of explained variance), and a plot of PC1 scores versus maturation time showed differences in colour and anthocyanins between ports matured in different containers. Ports matured in oak casks developed at a faster rate than the other ports. Total phenolics remained fairly constant in all ports, as monomeric anthocyanins were rapidly depleted during the time of maturation. Polymeric pigments formed during maturation contributed to increases in colour density, hue and the rate of browning. Differences in redox potential between wood matured ports and non‐wood matured ports indicated that there were differences in dissolved oxygen which could have affected the maturation rate of these wines.

© 2001 Society of Chemical Industry
Clinical significance of E‐cadherin expression in thyroid neoplasms
Authors: Naito Akihiro , Iwase Hirotaka , Kuzushima Tatsuya , Nakamura Takaaki , Kobayashi Shunzo
Published: August 2002

Background and Objective

E‐cadherin, a calcium‐dependent transmembrane glycoprotein, is an adhesion molecule. We studied clinical significance of E‐cadherin expression in thyroid neoplasms.

Methods

We immunohistochemically studied E‐cadherin expression in 60 normal tissue specimens of thyroid tissues and in 82 follicular adenomas, 53 papillary carcinomas, 4 follicular carcinomas, 2 medullary carcinomas, and 5 anaplastic carcinomas of the thyroid.

Results

In papillary carcinoma, E‐cadherin expression was preserved significantly less often than in follicular adenoma or normal thyroid tissue (P < 0.01). Preserved E‐cadherin expression was seen less often among papillary carcinomas with lymph node metastasis than in those without metastasis (P < 0.05).

Conclusions

This loss of E‐cadherin expression may be involved in regional lymph node metastasis and in malignant potential of thyroid neoplasms. J. Surg. Oncol. 2001;76:176–180. © 2001 Wiley‐Liss, Inc.
Trace element levels in the experimental peritonitis
Authors: Konukoğlu Dildar , Ercan Meltem , Ziylan Erkal
Published: August 2002

Electron transfer from iron or copper ions to oxygen is an important example of cellular free radical initiation. Oxygen‐derived free radicals have been implicated as mediators of cellular injury in several model systems. To evaluate the importance of iron, copper, and zinc levels on lipid peroxidation in peritonitis, we measured peritoneum malondialdehyde (MDA) as a marker of lipid peroxidation, zinc, copper, and iron levels during an animal model of intraperitoneal sepsis. Additionally, the effects of free radical scavenger alpha‐tocopherol administration were studied. The peritoneum MDA, iron, copper, and zinc levels were increased after induction of peritonitis with Escherichia coli. The treatment with alpha‐tocopherol decreased peritoneum MDA, iron, and copper levels significantly but not the zinc levels. Additionally, the treatment with alpha‐tocopherol 3 days prior to injection of E. coli decreased MDA, copper, and iron levels more than treatment with alpha‐tocopherol at the time of injection of E. coli. Our results indicate that copper, iron, and zinc have important effects on peroxidation events in E. coli‐induced peritonitis and that alpha‐tocopherol treatment can improve the oxidant status. J. Trace Elem. Exp. Med. 15:79–84, 2002. © 2002 Wiley‐Liss, Inc.
Effect of melatonin treatment on serum and tissue zinc levels in rats
Authors: Öztürk Güler , Coşkun Şule , Erbaş Deniz , Altunkaynak Bülent
Published: August 2002

Melatonin (MEL) is the main neuro‐hormone of the pineal gland. The main physiological function of MEL is to modulate variations of the light‐dark cycle and seasonal periodicity on various physiological functions. Zinc (Zn) is required as a catalytic component for more than 200 enzymes and is a structural constituent of many proteins, hormones, neuropeptides, and receptors. In addition, tissue Zn levels have been found to be altered after pinealectomy in rats. Recent findings have shown that MEL can modulate Zn turnover. In the present study, we investigated the effect of MEL treatment on the tissue and serum Zn levels. Male Spraque–Dawley rats (n = 24) were used. Rats received seven daily subcutaneous injections of MEL (10 mg/kg). After 7 days, rats were decapitated at 10:00 a.m. and 02:00 a.m., which were the periods of lowest and highest serum MEL levels, respectively. Blood and tissue samples were collected, and Zn levels were measured by atomic absorption spectrophotometry. In conclusion, MEL increased Zn levels in the salivary glands and small intestine. Daytime liver Zn levels and nighttime serum Zn levels increased in MEL‐treated group. There was no significant difference in brain after MEL treatment. Nighttime serum MEL levels were higher than daytime in both control and MEL‐treated group. In addition, MEL levels in MEL‐treated groups were significantly higher than those of control groups. It is clear that there is a tight relationship between Zn and MEL. J. Trace Elem. Exp. Med. 15:1–8, 2002. © 2002 Wiley‐Liss, Inc.
Spectroscopy of hydrothermal reactions, 19: pH and salt dependence of decarboxylation of α‐alanine at 280–330°C in an FT‐IR spectroscopy flow reactor
Authors: Li Jun , Wang Xiaogong , Klein Michael T. , Brill Thomas B.
Published: August 2002

The spontaneous decarboxylation of 0.5 m aqueous α‐alanine solutions as a function of pH (1–9 at 320°C, where neutrality is approximately 6) was determined with a flow reactor at 280–330°C and 275 bar by FT‐IR spectroscopy. The kinetics for the cationic and anionic forms have not been previously reported. The rate constants for the cationic form [CH3(NH3+)CHCO2H], the anionic form [CH3(NH2)CHCO2−], and the zwitterion form [CH3(NH3+)CHCO2−] were obtained and followed the first‐order rate law. The rate of decarboxylation of the zwitterion is three times greater than that of the cationic and anionic forms in the temperature and pH ranges of study. The corresponding Arrhenius parameters were determined and compared with previously reported data. The addition of KCl (1 and 2 m) at the natural pH of α‐alanine resulted in a reduction of the decarboxylation rate, suggesting that the transition state is less polar than the zwitterion and/or that the activity of the zwitterion has been reduced. The α‐alanine solution is therefore somewhat more robust in solutions of high ionic strength, such as seawater, than it is in pure water. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 271–277, 2002
Knowledge management and decision support for electrical power utilities
Authors: West G. M. , Strachan S. M. , Moyes A. , McDonald J. R. , Gwyn B. , Farrell J.
Published: August 2002

This paper describes a case study for a knowledge management project carried out in conjunction with two major UK electrical utilities. The focus of the work is on the design of protection schemes for electrical power transmission systems. A brief overview is provided of the traditional protection system design processes implemented within both companies and the associated shortcomings relating to the management of the data, information and knowledge throughout this process. The development of the Design Engineering Knowledge Application System (DEKAS), designed to address the knowledge management issues within both companies, is described, and the perceived benefits this system offers the existing protection design and application process of each company will be discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Transscleral optical coherence tomography—An experimental study in ex‐vivo human eyes*†
Authors: Hoerauf Hans , Winkler Jörg , Scholz Christian , Wirbelauer Christopher , Gordes Roswitha S. , Koch Peter , Engelhardt Ralf , Laqua Horst , Birngruber Reginald
Published: August 2002

Background and Objective

To evaluate the potentials of a 1310‐nm optical coherence tomography (OCT) system to penetrate the highly backscattering sclera in enucleated human eyes and provide visualization of intraocular structures by transscleral imaging.

Study Design/Materials and Methods

OCT‐images were generated by an experimental prototype (Medical Laser Center, Lübeck, Germany) using a superluminescence diode with a wavelength of 1310 nm. OCT‐images were taken from two enucleated human eyes using 100–200 axial scans with 60 Hz line scan frequency and compared to subsequent histologic sections.

Results

Transscleral OCT allowed penetration of the sclera and the anterior chamber angle could be completely identified. Some change within the anterior eye segment could be demonstrated with high accuracy. Additionally, limited demonstration of the ciliary body region was achieved. Due to limited signal intensity no detailed imaging of the pars plana and pars plicata region was possible. However, more posterior measurements allowed transscleral visualization of a retinal detachment.

Conclusions

OCT using lightsources with a wavelength longer than that used in conventional OCT provides a promising imaging technique at high resolution allowing transscleral imaging of the anterior eye segment. Lasers Surg. Med. 30:209‐215, 2002. © 2002 Wiley‐Liss, Inc.
Enhanced adenoviral‐vector mediated gene transfer using human albumin solder
Authors: Rivera Arnold DC , Walker Charles N. , Bleustein Clifford , Choi Benjamin , Poppas Dix P. , Felsen Diane
Published: August 2002

Background and Objective

Laser tissue welding with human albumin solder (HAS) has been used as an alternative method of wound closure. Adenoviral vectors have been used to introduce various cytokine genes into wounds to accelerate wound closure. In the present study, we were interested in the effect of HAS on adenoviral vector transfer of the β‐galactosidase (β‐gal) gene in vitro and in vivo.

Study Design/Materials and Methods

3T3 fibroblasts were used to study the effect of HAS on β‐gal gene transfer in vitro. The presence of β‐gal was determined by Western blot, and its activity by a colorimetric assay. A punch biopsy model of wound healing in pigs was used for in vivo experiments.

Results

HAS increased the efficiency of adenoviral‐mediated β‐gal transduction and stabilized the adenovirus at room temperature. HAS protected adenovirus from inactivation by laser, both in vitro and in vivo.

Conclusions

HAS may stabilize adenoviral vectors to deliver cytokine genes in future wound healing experiments. Lasers Surg. Med. 30:313–319, 2002. © 2002 Wiley‐Liss, Inc.
Adhesion of Er:YAG laser‐irradiated dentin and composite resins: Application of various treatments on irradiated surface
Authors: Eguro Toru , Maeda Toru , Otsuki Masahito , Nishimura Yaeko , Katsuumi Ichiroh , Tanaka Hisayoshi
Published: August 2002

Background and Objectives

The investigation of adhesion between an Er:YAG laser‐irradiated surface and composite resin is very important to ensure the best clinical results. The purpose of this investigation is to determine if the application of various treatments on Er:YAG laser‐irradiated dentin surface affects the tensile bond strength between dentin and composite resins.

Study Design/Materials and Methods

In this investigation, the application of phosphoric acid, ultrasonic scaler, air‐scaler, and air‐powder polisher were tested as techniques to increase the bond strength of composite resins to Er:YAG laser‐irradiated dentin surface.

Results

The tensile bond strength of the air‐powder polished group was highest, at 18.45 ± 3.72 MPa, and the lowest value was that of the only laser‐irradiated group, at 12.56 ± 4.38 MPa.

Conclusions

The bond strengths in treated with air‐powder polished group and phosphric acid etched group were significantly higher than that of the group in laser irradiation alone. Lasers Surg. Med. 30:267–272, 2002. © 2002 Wiley‐Liss, Inc.