bluuebunny/crossref_metadata_2025 huggingface dataset:
Mixed lineage kinase–c‐jun N‐terminal kinase signaling pathway: A new therapeutic target in Parkinson's disease
Authors: Silva Robert M. , Kuan Chia‐Yi , Rakic Pasko , Burke Robert E.
Published: February 2005

There is growing evidence that the molecular pathways of programmed cell death play a role in neurodegenerative disease, including Parkinson's disease, so there has been increased interest in them as therapeutic targets for the development of neuroprotective strategies. One pathway of cell death that has attracted particular attention is the mixed lineage kinase (MLK) –c‐jun N‐terminal kinase (JNK) signaling cascade, which leads to the phosphorylation and activation of the transcription factor c‐jun. There is much evidence, from in vitro and in vivo studies, that this cascade can mediate cell death. In addition, there is evidence that it is operative upstream in the death process. It is possible that abrogation of this pathway may forestall death before irreversible cellular injury. One class of compounds that has shown promise for their ability to block cell death by inhibiting this cascade are the inhibitors of the MLKs, which are upstream in the activation of c‐jun. One of these compounds, CEP1347, is now in a Phase II/III clinical trial for neuroprotection in PD. Whether this trial is successful or not, this signaling cascade is likely to be a focus of future therapeutic development. This review, therefore, outlines the principles of signaling within this kinase pathway, and the evidence for its role in cell death. We review the evidence that inhibition of the MLKs can prevent dopamine neuron cell death and the degeneration of their axons. These studies suggest important future directions for the development of therapies that will target this important cell death pathway. © 2005 Movement Disorder Society
Striatal synaptic plasticity: Implications for motor learning and Parkinson's disease
Authors: Pisani Antonio , Centonze Diego , Bernardi Giorgio , Calabresi Paolo
Published: February 2005

Changing the strength of synaptic connections between neurons is widely assumed to be the mechanism by which memory traces are encoded and stored in the central nervous system. Plastic changes appear to follow a regional specialization and underlie the specific type of memory mediated by the brain area in which plasticity occurs. Thus, long‐term changes occurring at excitatory corticostriatal synapses should be critically involved in motor learning. Indeed, repetitive stimulation of the corticostriatal pathway can cause either a long‐lasting increase or an enduring decrease in synaptic strength, respectively referred to as long‐term potentiation (LTP), and long‐term depression, both requiring a complex sequence of biochemical events. Once established, LTP can be reversed to control levels by a low‐frequency stimulation protocol, an active phenomenon defined “synaptic depotentiation,” required to erase redundant information. In the 6‐hydroxydopamine rat model of Parkinson's disease (PD), striatal synaptic plasticity has been shown to be impaired, although chronic treatment with levodopa was able to restore it. Of interest, a consistent number of L‐dopa–treated animals developed involuntary movements, resembling human dyskinesias. Strikingly, electrophysiological recordings from the dyskinetic group of rats demonstrated a selective impairment of synaptic depotentiation. This survey will provide an overview of plastic changes occurring at striatal synapses. The potential relevance of these findings in the control of motor function and in the pathogenesis both of PD and L‐dopa–induced motor complications will be discussed. © 2005 Movement Disorder Society
Self‐assembled honeycomb polycarbonate films deposited on polymer piezoelectric substrates and their applications
Authors: Bormashenko Edward , Pogreb Roman , Stanevsky Oleg , Bormashenko Yelena , Socol Yehoshua , Gendelman Oleg
Published: February 2005

Self‐assembled honeycomb polycarbonate films were deposited on polymer piezoelectric (poled polyvinylidene fluoride) substrates under a fast dip‐coating process. Ordered structures with micro‐scaled pores dispersed in the polycarbonate matrix were obtained, demonstrating two‐dimensional (2D) hexagonal packing. A theoretical model explaining the self‐assembling process is proposed. Fabricated structures have a potential as 2D tunable photonic crystals. Photonic bandgap location was estimated. Visible‐IR transmittance spectrum of the self‐assembled films was studied with a FT‐IR spectrometer. Diffraction properties of the honeycomb patterns were investigated. High transparency of the components makes possible IR optics applications of obtained structures. Copyright © 2005 John Wiley & Sons, Ltd.
Short carbon fiber reinforced aromatic polydisulfide derived from cyclic (4,4′‐oxybis(benzene)disulfide) via ring‐opening polymerization
Authors: Song L. N. , Du X. S. , Xiao M. , Meng Y. Z.
Published: February 2005

Morphology, mechanical and thermal properties of short carbon fiber reinforced poly(arylene disulfide) synthesized by ring‐opening reaction of cyclic(arylene disulfide) oligomers were studied. These macrocyclic oligomers were prepared from 4,4′‐oxybis(benzenethiol) by oxidation coupling cyclization. Ring‐opening polymerization (ROP) was carried out by in situ melt molding in air. Oxidation reaction during the ROP was detected using the Raman spectrum technique. Three‐point bending tests were performed to determine the flexural properties of neat polymers and the composites. The results showed that the flexural strength and modulus of poly(arylene disulfide)/carbon fiber composites were greatly enhanced with the carbon fiber addition. The maximum weight loss peak temperatures of the composites increased with increasing short carbon fiber content. Good adhesion between carbon fiber and the matrix was observed using scanning electron microscopy (SEM) technique. Copyright © 2005 John Wiley & Sons, Ltd.
Intrinsically conducting polymers for electromagnetic interference shielding
Authors: Wang Yangyong , Jing Xinli
Published: February 2005

This paper summarizes and reviews the research on electromagnetic interference (EMI) shielding with intrinsically conducting polymers (ICPs), mainly polyaniline (PANI) and polypyrrole (PPY), and their composites in various frequency ranges. ICPs are new alternative candidates for EMI shielding applications due to their lightweight, corrosion resistance, ease of processing, and tunable conductivities as compared with typical metals. More importantly, the dominant shielding characteristic of absorption other than that of reflection for metals render ICPs more promising materials in applications requiring not only high EMI shielding effectiveness but also shielding by absorption, such as in stealth technology. Copyright © 2005 John Wiley & Sons, Ltd.
Spin structure and properties of the correlation matrices corresponding to pure spin states: Controlling the S‐representability of these matrices
Authors: Alcoba D. R. , Valdemoro C.
Published: February 2005

In this paper we investigate the S‐representability conditions that a two‐body correlation matrix must satisfy when the N‐electron system is in a given pure spin state. To purify a trial two‐body correlation matrix, the N‐ and S‐representability conditions are combined in a computational procedure for singlet states. This procedure is tested in two calculations on a molecular system and the results are discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Carcinogenic classification of polycyclic aromatic hydrocarbons through theoretical descriptors
Authors: Troche Karla S. , Braga Scheila F. , Coluci Vitor R. , Galvão Douglas S.
Published: February 2005

Polycyclic aromatic hydrocarbons (PAHs) constitute an important family of molecules capable of inducing chemical carcinogenesis. In this work we report a comparative structure–activity relationship (SAR) study for 81 PAHs using different methodologies. The recently developed electronic indices methodology (EIM) with quantum descriptors obtained from different semiempirical methods (AM1, PM3, and PM5) was contrasted against more standard pattern recognition methods (PRMs), principal component analysis (PCA), hierarchical cluster analysis (HCA), Kth nearest neighbor (KNN), soft independent modeling of class analogies (SIMCA), and neural networks (NN). Our results show that PRMs validate the statistical value of electronic parameters derived from EIM analysis and their ability to identify active compounds. EIM outperformed more standard SAR methodologies and does not appear to be significantly Hamiltonian‐dependent. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Does antenatal identification of small‐for‐gestational age fetuses significantly improve their outcome?
Authors: Lindqvist P. G. , Molin J.
Published: February 2005

Objectives

Most obstetric clinics have a program for the identification of small‐for‐gestational age (SGA) fetuses because of the increased risk of fetal complications that they present. We have a structured model for the identification and follow‐up of SGA pregnancies. We aimed to determine whether the recognition of SGA antepartum improves fetal outcome.

Methods

All pregnancies at Malmö University Hospital from 1990 to 1998 (n = 26 968) were reviewed. SGA fetuses identified prior to delivery (n = 681) were compared with those not identified (n = 573). Also, all pregnancies with SGA fetuses were compared with those appropriate‐for‐gestational age (AGA) (n = 24 585). The risk of serious fetal complications (hypoxic encephalopathy grade 2 or 3, intracranial hemorrhage, Apgar score <4 at 5 min, neonatal convulsions, umbilical pH <7.0, cerebral palsy, mental retardation, stillbirth, intrapartum or infant death) was assessed with cross‐tabulation and logistic regression analysis, adjusted for gestational age and degree of SGA.

Results

When compared with SGA fetuses identified before delivery (54%), SGA fetuses not identified before delivery were characterized by a four‐fold increased risk of adverse fetal outcome (odds ratio, 4.1; 95% CI, 2.5–6.8). Similarly, compared with AGA fetuses, SGA fetuses were associated with a four‐fold increased risk of serious fetal complications.

Conclusions

A structured antenatal surveillance program for fetuses identified as SGA results in a lower risk of adverse fetal outcome, compared with cases of SGA fetuses not identified antepartum. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Cell lines from xeroderma pigmentosum complementation group A lack a single-stranded-DNA-binding activity
Authors: Kuhnlein Urs , Tsang Siu Sing , Lokken Opal , Tong Silvian , Twa Daniel
Published: February 2005

Human fibroblasts and HeLa cells contain two major DNA-binding activities for superhelical DNA, which can be separated by phosphocellulose chromatography. The DNA-binding activity which elutes first from the column coelutes with and is probably identical to a single-stranded-DNA-binding activity. The second activity has been characterized previously. It binds preferentially to super-helical DNA containing DNA damage, but does not bind to single-stranded DNA. Five cell lines derived from patients with the repairdeficiency syndrome xeroderma pigmentosum (XP) were analyzed for the presence of these binding activities. Four of the cell lines were from the A-complementation group and one was from the D-complementation group of XP. The binding activity with preference for damaged DNA was present in all cell lines. The single-stranded-DNA-binding activity was present in the XP-D cell line but was absent or reduced in all of the four XP-A cell lines tested.
High-affinity folate binding in human liver membranes
Authors: Holm Jan , Hansen Steen Ingemann , Høier-Madsen Mimi
Published: February 2005

High-affinity binding of3H-folate in Triton X-100 solubilized membranes of human liver displayed characteristics, e.g. apparent positive cooperativity, which are typical of specific folate binding. Ultrogel® AcA 44 chromatography of solubilized membranes saturated with3H-folate revealed a major peak of 100 kDa and a minor peak of 25 kDa. The 100 kDa peak could represent a hydrophobic membrane associated molecular form of the protein. This notion was supported by the fact that the two peaks had identical molecular weights as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis with immunoblotting.
Primary Cutaneous CD30-Positive Anaplastic Large Cell Lymphoma in Childhood: Report of 4 Cases and Review of the Literature
Authors: Kumar Shimareet , Pittaluga Stefania , Raffeld Mark , Guerrera Michael , Seibel Nita L. , Jaffe Elaine S.
Published: February 2005

We present the clinicopathologic findings in 4 children with primary cutaneous anaplastic large cell lymphoma (C-ALCL). The patients ranged in age from 13 months to 8 years, with 3 females and 1 male. All presented with a rapidly enlarging mass involving the skin and subcutaneous tissue. Histologic evaluation showed sheets of large pleomorphic lymphoid cells that were diffusely and strongly CD30+. Tumor cells were CD45+ in 1 of 4 cases. Cells were of T-cell phenotype, with variable positivity for CD3 (3 of 4 cases) and CD5 (2 of 4 cases). All 4 cases were positive for CD4 and clusterin. Staining for anaplastic lymphoma kinase was negative in all cases. No evidence of systemic involvement was noted at initial presentation or over a follow-up of 5 to 78 months, although 3 patients had cutaneous recurrences. Primary C-ALCL has only rarely been described in the pediatric population. The high-grade histologic appearance of this lymphoma belies its generally favorable clinical course and prognosis. Recognition of this entity and its differentiation from other T-cell lymphomas that secondarily involve the skin is important to avoid unnecessarily aggressive therapy in these children.
Identification of Lymphatic Endothelium in Pediatric Vascular Tumors and Malformations
Authors: Galambos Csaba , Nodit Laurentia
Published: February 2005

The distinction between lymphatic and other vascular vessels on microscopic sections is a challenging task. D2-40, a novel antibody, has been reported to be selective for lymphatic endothelium. We studied the specificity and sensitivity of D2-40 in pediatric vascular tumors and malformations. Fourteen lymphatic and 11 vascular lesions were randomly selected and stained with D2-40 and CD31 antibodies. The lymphatic lesions included 6 lymphatic malformations, 5 cystic hygromas (macrocystic lymphatic malformation), 2 lymphovenous malformations, and 1 lymphangioma, and the vascular lesions comprised 3 infantile hemangiomas, 3 Kaposiform hemangioendotheliomas, 2 tufted angiomas, 1 pyogenic granuloma, 1 arteriovenous, and 1 venulocapillary malformations. The staining patterns of the vascular channels were compared. In all lesions D2-40 labeled only the endothelium of thin-walled vascular channels morphologically consistent with lymphatic vessels (25 of 25). No staining of the vascular lesions (0 of 11) or of arteries and veins (0 of 25) was observed. All lymphatic lesions had D2-40–positive vessels; however, the percentage of vessels that stained varied. Five lymphatic lesions showed more than 75% D2-40–positive channels, 5 lesions had approximately 50%, and 4 cases showed fewer than 25% D2-40–positive channels. There was a tendency of more consistent D2-40 staining of small versus large lymphatic channels. CD31 constantly labeled arteries, veins, capillaries, and lymphatics in all lesions and all endothelial cells in the vascular lesions. D2-40 is a very specific antibody for lymphatic endothelium, with variable sensitivity. CD31 more reliably identifies lymphatic endothelium. Currently, D2-40 appears to be a good marker to identify lymphatic vessels in pediatric vascular tumors and malformations.
Adjunctive use of reboxetine in schizophrenia
Authors: Raedler Thomas J. , Jahn Holger , Arlt Josef , Kiefer Falk , Schick Mildred , Naber Dieter , Wiedemann Klaus
Published: February 2005

Background

Schizophrenia is frequently complicated by depressive or negative symptoms that respond only moderately to treatment with antipsychotic drugs. Reboxetine is a novel antidepressant, which inhibits the reuptake of norepinephrine. We sought to study the efficacy and tolerability of the adjunctive use of reboxetine in a cohort of schizophrenic patients with prominent depressive or negative symptoms.

Methods

Sixteen schizophrenic inpatients were recruited for this study. All subjects received 4–8 mg of reboxetine/day while the antipsychotic medication (typical antipsychotics = 4; atypical antipsychotics = 12) was continued. All subjects underwent a standardized assessment including PANSS, CGI, HAMD, and CDSS before and after treatment with reboxetine (mean 26 ± 17 d).

Results

All subjects tolerated treatment with reboxetine. Adverse effects were mild and did not require discontinuation of reboxetine. All clinical scores (PANSS 93.1 vs. 63.1; CGI 5.4 vs. 4.1; HAMD 20.4 vs. 8.1; CDSS 12.5 vs. 4.6) improved significantly under adjunctive treatment with reboxetine (allP< 0.01).

Conclusion

The adjunctive use of reboxetine in schizophrenic patients was safe and well-tolerated. Our results suggest that the adjunctive use of reboxetine may be an effective treatment for depressive and negative symptoms in schizophrenia.
The planning flexibility bottleneck in food processing industries
Authors: Van Wezel Wout , Van Donk Dirk Pieter , Gaalman Gerard
Published: February 2005

Production planners in food processing industries must continuously balance efficient production with flexible performance. On the basis of case studies, we state that flexibility is not only restrained by hard‐wired production process characteristics, but also by organizational procedures in the planning process. Planning practice in food processing industries is often not able to make the most of the available flexibility in the production processes, and our analysis shows that existing production planning approaches, ERP systems, and advanced planning systems can only partly resolve this. We propose a planning framework that can help to analyze the flexibility of the planning. The planning framework relates planning events to the way in which planning decisions are structured in the planning organization.
Dynamics of vertical mixing in a shallow lake with submersed macrophytes
Authors: Herb William R. , Stefan Heinz G.
Published: February 2005

A model for vertical turbulent diffusion and stratification in a shallow lake with submersed macrophytes is formulated on the basis of a one‐dimensional equation for production, transport, and dissipation of turbulent kinetic energy, coupled with a vertical heat transfer equation. Numerical solutions of the coupled equations allow simulation of the hourly variation of water temperature profiles in a shallow lake as a function of varying weather parameters. The model can be used to simulate water temperature and turbulent kinetic energy profiles in locations of a shallow lake with either dense macrophyte beds or relatively open water. The water temperature simulations are in good agreement with field data from a shallow lake. During the day, macrophyte beds are found to increase the strength of temperature stratification and to reduce the mixed layer depth compared to open water. Macrophyte beds are found to have relatively little effect on nighttime deepening of the mixed layer because of surface cooling. Lateral transport between open water and macrophyte beds of finite horizontal dimensions (patchiness) may limit the accuracy of one‐dimensional transport models. Vertical diffusivity coefficient profiles found in this study may be useful to investigate mass transport in shallow lakes with macrophytes.
The North Atlantic Oscillation and greenhouse‐gas forcing
Authors: Kuzmina Svetlana I. , Bengtsson Lennart , Johannessen Ola M. , Drange Helge , Bobylev Leonid P. , Miles Martin W.
Published: February 2005

The results of 12 coupled climate models participating in the Coupled Model Intercomparison Project (CMIP2) are compared together with observational data in order to investigate: 1) How the current generation of climate models reproduce the major features of the winter North Atlantic Oscillation (NAO), and 2) How the NAO intensity and variability may change in response to increasing atmospheric CO2 concentration. Long‐term changes in the intensity and spatial position of the NAO nodes (Icelandic Low and Azores High) are investigated, and different definitions of the NAO index and the Arctic Oscillation (AO) are considered. The observed temporal trend in the NAO in recent decades lies beyond the natural variability found in the model control runs. For the majority of the models, there is a significant increase in the NAO trend in the forced runs relative to the control runs, suggesting that the NAO may intensify with further increases in greenhouse‐gas concentrations.
Contributions of denitrification and mixing on the distribution of nitrous oxide in the North Pacific
Authors: Yamagishi Hiroaki , Yoshida Naohiro , Toyoda Sakae , Popp Brian N. , Westley Marian B. , Watanabe Shuichi
Published: February 2005

We analyzed N2O isotopomer ratios (distribution of isotopes within N2O molecules) in the eastern tropical North Pacific. The N2O isotopomer ratios indicate the contribution of denitrification in the oxygen minimum zone (OMZ, ∼600 m in depth) in the western North Pacific, which is not consistent with the widely accepted nitrification hypothesis. Our models indicate that the N2O yield per mole O2 consumed (dN2O/−dO2) is 0.008 (0–0.015) nmol/μmol during remineralization and nitrification in the western North Pacific. Nitrification in aerobic deep waters is a minor source of oceanic N2O, whereas the N2O production in the OMZ is the dominant factor for the oceanic N2O distribution. The denitrification in the OMZ is consistent with the correlation between ΔN2O (level above atmospheric equilibrium) and AOU (apparent oxygen utilization), and the parallel 18O‐enrichment of N2O and O2 in the OMZ, which have been believed to support the nitrification hypothesis.
Wind driven upwelling along the African coast of the Strait of Gibraltar
Authors: Stanichny S. , Tigny V. , Stanichnaya R. , Djenidi S.
Published: February 2005

Regular remote sensing data from various sensors are used here for the study of the wind driven upwelling phenomenon along the African coast of the Strait of Gibraltar. It is shown for an extended summer period (May 15 till September 15, 2003) that sea surface temperature (SST) data in the strait are correlated with NCEP winds, each westward wind increase being followed by a clear surface temperature decrease. Local surface temperature of about 22°C at that time drops down to 15°C, value corresponding to the 80–120 m depth conditions. The analysis of subsequent images indicates that the cold upwelling plume typically moves first to the Atlantic during wind forcing, and then to the Mediterranean after the wind event. The presence of the northern coast of the strait is taken as responsible for a rise of a cross‐strait sea level gradient and the enhancement of the associated westward geostrophic current that explains the first stage of the plume deployment. Sea level difference measured between Tarifa (European coast) and Ceuta (African coast), well described by a linear equation in term of the westward wind component, supports this idea as well as the subsequent remotely sensed SST distributions.
A global framework for monitoring phenological responses to climate change
Authors: White Michael A. , Hoffman Forrest , Hargrove William W. , Nemani Ramakrishna R.
Published: February 2005

Remote sensing of vegetation phenology is an important method with which to monitor terrestrial responses to climate change, but most approaches include signals from multiple forcings, such as mixed phenological signals from multiple biomes, urbanization, political changes, shifts in agricultural practices, and disturbances. Consequently, it is difficult to extract a clear signal from the usually assumed forcing: climate change. Here, using global 8 km 1982 to 1999 Normalized Difference Vegetation Index (NDVI) data and an eight‐element monthly climatology, we identified pixels whose wavelet power spectrum was consistently dominated by annual cycles and then created phenologically and climatically self‐similar clusters, which we term phenoregions. We then ranked and screened each phenoregion as a function of landcover homogeneity and consistency, evidence of human impacts, and political diversity. Remaining phenoregions represented areas with a minimized probability of non‐climatic forcings and form elemental units for long‐term phenological monitoring.
The effect of Denmark Strait overflow on the Atlantic Meridional Overturning Circulation
Authors: Kösters F. , Käse R. H. , Schmittner A. , Herrmann P.
Published: February 2005

Hydraulic constraints on the Denmark Strait overflow (DSO) are used as a parameterisation to improve the overflow representation in a global climate model. The parameterisation increases deep water formation in the Nordic Seas and strengthens the Norwegian Atlantic Current. Associated higher northward heat transport leads to a northward shift of the sea‐ice edge and warming by 2.5°C in the eastern Nordic Seas despite a small effect on the Atlantic Meridional Overturning Circulation (AMO). This emphasises the impact of the DSO on climate even though the response in overturning due to the DSO representation in this model is less than expected from previous studies using ocean only models. In contrast to previous studies almost no stabilising effect of the overflow on the AMO is found to freshwater perturbations.
Variation in isoprene emission from Quercus rubra: Sources, causes, and consequences for estimating fluxes
Authors: Funk Jennifer L. , Jones Clive G. , Gray Dennis W. , Throop Heather L. , Hyatt Laura A. , Lerdau Manuel T.
Published: February 2005

Isoprene is the dominant volatile organic compound produced in many forest systems. Uncertainty in estimates of leaf level isoprene emission rate stems from an insufficient understanding of the patterns and processes controlling isoprene emission capacity in plant leaves. Previous studies suggest that variation in isoprene emission capacity is substantial; however, it is not known at what scale emission capacity is the most variable. Identifying the sources of variation in emission capacity has implications for conducting measurements and for model development, which will ultimately improve emission estimates and models of tropospheric chemistry. In addition, understanding the sources of variation will help to develop a comprehensive understanding of the physiological controls over isoprene emission. This study applied a variance partitioning approach to identify the major sources of variation in isoprene emission capacity from two populations of northern red oak (Quercus rubra) over three growing seasons. Specifically, we evaluated variation due to climate, populations, trees, branches, leaves, seasons, and years. Overall, the dominant source of variation was the effect of a moderate drought event. In the years without drought events, variation among individual trees (intraspecific) explained approximately 60% of the total variance. Within the midseason, isoprene emission capacity of sun leaves varied by a factor of 2 among trees. During the third year a moderate 20‐day drought event caused isoprene emission capacity to decrease fourfold, and the relative importance of intraspecific variation was reduced to 24% of total variance. Overall, ambient temperature, light, and a drought index were poor predictors of isoprene emission capacity over a 0 to 14‐day period across growing seasons. The drought event captured in this study emphasizes the need to incorporate environmental influences into leaf level emission models.
Total soil organic matter and its labile pools following mulga (Acacia aneura) clearing for pasture development and cropping 1. Total and labile carbon
Authors: Dalal R. C. , Harms B.P. , Krull E. , Wang W.J.
Published: February 2005

Mulga (Acacia aneura) dominated vegetation originally occupied 11.2 Mha in Queensland, of which 12% has been cleared, mostly for pasture production, but some areas are also used for cereal cropping. Since mulga communities generally occupy fragile soils, mostly Kandosols and Tenosols, in semi-arid environments, clearing of mulga, which continues at a rate of at least 35 000 ha/year in Queensland, has considerable impact on soil organic carbon (C), and may also have implications for the greenhouse gas emissions associated with land use change in Australia. We report here the changes in soil C and labile C pools following mulga clearing to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for 20 years in a study using paired sites.
Soil organic C in the top 0.05 m of soil declined by 31% and 35% under buffel pasture and cropping, respectively. Land use change from mulga to buffel and cropping led to declines in soil organic C of 2.4 and 4.7 t/ha, respectively, from the top 0.3 m of soil. Using changes in the δ13C values of soil organic C as an approximate representation of C derived from C3 and C4 vegetation from mulga and buffel, respectively, up to 31% of soil C was C4-derived after 20 years of buffel pasture. The turnover rates of mulga-derived soil C ranged from 0.035/year in the 0–0.05 m depth to 0.008/year in the 0.6–1 m depths, with respective turnover times of 29 and 133 years. Soil organic matter quality, as measured by the proportion/amount of labile fraction C (light fraction, < 1.6 t/m3) declined by 55% throughout the soil profile (0–1 m depth) under both pasture and cropping.
There is immediate concern for the long-term sustainable use of land where mulga has been cleared for pasture and/or cropping with a continuing decline in soil organic matter quality and, hence, soil fertility and biomass productivity. In addition, the removal of mulga forest over a 20-year period in Queensland for pasture and cropping may have contributed to the atmosphere at least 12 Mt CO2-equivalents.
Soil bulk density evaluation by conventional and nuclear methods
Authors: Timm L. C. , Pires L. F. , Reichardt K. , Roveratti R. , Oliveira J. C. M. , Bacchi O. O. S.
Published: February 2005

Among the methods used to measure soil bulk density, the following have been prominent: paraffin sealed clod (PS), volumetric ring (VR), and the modern methods like gamma ray computed tomography (GCT) and the neutron/gamma surface gauge (SG). The objective of this work was to compare soil bulk density values obtained through these methods, with the aim of assisting researchers on the choice of the more appropriate method. For this, a 200-m spatial transect was chosen in an experimental area cultivated with coffee, belonging to ESALQ/USP, Piracicaba, SP, Brazil. The SG readings were first taken in the field and thereafter soil samples were collected at 8 different points, spaced at 25 m, for the other methods. The lowest values of soil bulk density were obtained for the SG method (average 1.468 g/cm3) and the highest for the PS (average 1.685 g/cm3), which was similar to the GCT method (average 1.684 g/cm3). The average soil bulk density for the VR method, which has been used in soil science as a standard method, was 1.544 g/cm3. The Tukey test indicates that the PS and GCT methods do not differ significantly (P > 0.05). They do differ in comparison with VR and SG, which also do not differ among themselves.
Changes in surface water quality after inundation of acid sulfate soils of different vegetation cover
Authors: Johnston S. G. , Slavich P. G. , Hirst P.
Published: February 2005

Surface soils from an acid sulfate soil (ASS) backswamp were inundated in a temperature controlled environment and surface-water chemistry changes monitored. The soils had contrasting in situ vegetative cover [i.e. 2 grass species, Cynodon dactylon and Pennisetum clandestinum (Poaceae), and litter from Melaleuca quinquenervia (Myrtaceae)]. The different vegetation types had similar biomass and carbon content; however, there were large differences in the quality and lability of that carbon, which strongly influenced decay/redox processes and the chemical composition of surface waters. The grass species had more labile carbon. Their surface waters displayed rapid sustained O2 depletion and sustained low Eh (~0 mV), high dissolved organic carbon (DOC), and moderate pH (5–6). Their soil acidity was partially neutralised, sulfides were re-formed, and reductive dissolution of Fe(III) led to the generation of stored acidity in the water column as Fe2+(aq). In contrast, M. quinquenervia litter was high in decay-resistant compounds. Its surface waters had lower DOC and low pH (<4) and only underwent a short period of low O2/Eh. Soluble Al caused M. quinquenervia surface waters to have higher titratable acidity and soil pH remained consistently low (~3.8–4.0). Concentrations of Cl– and Al in surface waters were strongly correlated to initial soil contents, whereas the behaviour of Fe and SO42– varied according to pH and redox status. This study demonstrates that changes in vegetation communities in ASS backswamps that substantially alter either (a) the pool of labile vegetative organic carbon or (b) the concentration of acidic solutes in surface soil can have profound implications for the chemical characteristics of backswamp surface waters.
Parkinson-like syndrome induced by continuous MPTP infusion: Convergent roles of the ubiquitin-proteasome system and α-synuclein
Authors: Fornai Francesco , Schlüter Oliver M. , Lenzi Paola , Gesi Marco , Ruffoli Riccardo , Ferrucci Michela , Lazzeri Gloria , Busceti Carla L. , Pontarelli Fabrizio , Battaglia Giuseppe , Pellegrini Antonio , Nicoletti Ferdinando , Ruggieri Stefano , Paparelli Antonio , Südhof Thomas C.
Published: February 2005

In animals, sporadic injections of the mitochondrial toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) selectively damage dopaminergic neurons but do not fully reproduce the features of human Parkinson's disease. We have now developed a mouse Parkinson's disease model that is based on continuous MPTP administration with an osmotic minipump and mimics many features of the human disease. Although both sporadic and continuous MPTP administration led to severe striatal dopamine depletion and nigral cell loss, we find that only continuous administration of MPTP produced progressive behavioral changes and triggered formation of nigral inclusions immunoreactive for ubiquitin and α-synuclein. Moreover, only continuous MPTP infusions caused long-lasting activation of glucose uptake and inhibition of the ubiquitin-proteasome system. In mice lacking α-synuclein, continuous MPTP delivery still induced metabolic activation, but induction of behavioral symptoms and neuronal cell death were almost completely alleviated. Furthermore, the inhibition of the ubiquitinproteasome system and the production of inclusion bodies were reduced. These data suggest that continuous low-level exposure of mice to MPTP causes a Parkinson-like syndrome in an α-synuclein-dependent manner.
Lessons from
Escherichia coli
genes similarly regulated in response to nitrogen and sulfur limitation
Authors: Gyaneshwar Prasad , Paliy Oleg , McAuliffe Jon , Jones Adriane , Jordan Michael I. , Kustu Sydney
Published: February 2005

We previously characterized nutrient-specific transcriptional changes in
Escherichia coli
upon limitation of nitrogen (N) or sulfur (S). These global homeostatic responses presumably minimize the slowing of growth under a particular condition. Here, we characterize responses to slow growth
per se
that are not nutrient-specific. The latter help to coordinate the slowing of growth, and in the case of down-regulated genes, to conserve scarce N or S for other purposes. Three effects were particularly striking. First, although many genes under control of the stationary phase sigma factor RpoS were induced and were apparently required under S-limiting conditions, one or more was inhibitory under N-limiting conditions, or RpoS itself was inhibitory. RpoS was, however, universally required during nutrient downshifts. Second, limitation for N and S greatly decreased expression of genes required for synthesis of flagella and chemotaxis, and the motility of
E. coli
was decreased. Finally, unlike the response of all other
met
genes, transcription of
metE
was decreased under S- and N-limiting conditions. The
metE
product, a methionine synthase, is one of the most abundant proteins in
E. coli
grown aerobically in minimal medium. Responses of
metE
to S and N limitation pointed to an interesting physiological rationale for the regulatory subcircuit controlled by the methionine activator MetR.
Partitions with short sequences and mock theta functions
Authors: Andrews George E.
Published: February 2005

P. A. MacMahon was the first to examine integer partitions in which consecutive integers were not allowed as parts. Such partitions may be described as having sequences of length 1. Recently it was shown that partitions containing no sequences of consecutive integers of length
k
are of interest in seemingly unrelated problems concerning threshold growth models. The object now is to develop the subject intrinsically to both provide deeper understanding of the theory and application of partitions and reveal the surprising role of Ramanujan's mock theta functions.
Relations between Agreeableness and perceived support in family relationships: Why nice people are not always supportive
Authors: Branje Susan J. T. , van Lieshout Cornelis F. M. , van Aken Marcel A. G.
Published: February 2005

Do more agreeable individuals perceive more support, and are they perceived as more supportive, across all family relationships or only within specific relationships? In a study of 256 Dutch two-parent families with two adolescents, we examine whether links between Agreeableness and support are generalised across relationships or occur within specific relationships. Social Relations Model analyses showed that individuals who perceive their family members as more agreeable perceive more support from family members across relationships. Also, individuals who are perceived as more agreeable are perceived as more supportive across relationships, except for mothers. In addition, individuals who perceive specific family members as more agreeable perceive these specific members as more supportive. However, individuals who are perceived as more agreeable perceive more support only within specific relationships. Thus, agreeable family members are supportive across relationships, but agreeable family members perceive support only within specific relationships.
N-Cadherin Association with Lipid Rafts Regulates Its Dynamic Assembly at Cell-Cell Junctions in C2C12 Myoblasts
Authors: Causeret Marie , Taulet Nicolas , Comunale Franck , Favard Cyril , Gauthier-Rouvière Cécile
Published: February 2005

Cadherins are homophilic cell-cell adhesion molecules implicated in cell growth, differentiation, and organization into tissues during embryonic development. They accumulate at cell-cell contact sites and act as adhesion-activated signaling receptors. Here, we show that the dynamic assembly of N-cadherin at cell-cell contacts involves lipid rafts. In C2C12 myoblasts, immunofluorescence and biochemical experiments demonstrate that N-cadherin present at cell-cell contacts is colocalized with lipid rafts. Disruption of lipid rafts leads to the inhibition of cell-cell adhesion and disorganization of N-cadherin–dependent cell-cell contacts without modifying the association of N-cadherin with catenins and its availability at the plasma membrane. Fluorescent recovery after photobleaching experiments demonstrate that at the dorsal plasma membrane, lipid rafts are not directly involved in the diffusional mobility of N-cadherin. In contrast, at cell-cell junctions N-cadherin association with lipid rafts allows its stabilization enabling the formation of a functional adhesive complex. We show that lipid rafts, as homophilic interaction and F-actin association, stabilize cadherin-dependent adhesive complexes. Homophilic interactions and F-actin association of N-cadherin are both required for its association to lipid rafts. We thus identify lipid rafts as new regulators of cadherin-mediated cell adhesion.
Quantitative Characterization of a Mitotic Cyclin Threshold Regulating Exit from Mitosis
Authors: Cross Frederick R. , Schroeder Lea , Kruse Martin , Chen Katherine C.
Published: February 2005

Regulation of cyclin abundance is central to eukaryotic cell cycle control. Strong overexpression of mitotic cyclins is known to lock the system in mitosis, but the quantitative behavior of the control system as this threshold is approached has only been characterized in the in vitro Xenopus extract system. Here, we quantitate the threshold for mitotic block in budding yeast caused by constitutive overexpression of the mitotic cyclin Clb2. Near this threshold, the system displays marked loss of robustness, in that loss or even heterozygosity for some regulators becomes deleterious or lethal, even though complete loss of these regulators is tolerated at normal cyclin expression levels. Recently, we presented a quantitative kinetic model of the budding yeast cell cycle. Here, we use this model to generate biochemical predictions for Clb2 levels, asynchronous as well as through the cell cycle, as the Clb2 overexpression threshold is approached. The model predictions compare well with biochemical data, even though no data of this type were available during model generation. The loss of robustness of the Clb2 overexpressing system is also predicted by the model. These results provide strong confirmation of the model's predictive ability.
Red cell deformability, splenic function and anaemia in thalassaemia
Authors: Dondorp A. M. , Chotivanich K. T. , Fucharoen S. , Silamut K. , Vreeken J. , Kager P. A. , White N. J.
Published: February 2005

Red cell deformability (RCD) was measured in 38 patients with α‐thalassaemia and 48 patients with β‐thalassaemia, of whom 13 had undergone splenectomy. All splenectomized patients, but none of those with intact spleens, had very rigid erythrocytes with an elongation index <0.45 at a high shear stress of 30 Pa suggesting a splenic recognition threshold for removal of rigid red cells. At this shear stress RCD correlated strongly with the degree of anaemia in both the splenectomized (r = 0.81, P < 0.001) and non‐splenectomized β‐thalassaemic patients (all patients r = 0.81, P < 0.001; homozygous β‐thalassaemic patients r = 0.51, P = 0.01). These data suggest that reduced RCD is a major determinant of anaemia in thalassaemia.
Replicative MCM7 protein as a proliferation marker in endometrial carcinoma: a tissue microarray and clinicopathological analysis
Authors: Li S S , Xue W C , Khoo U S , Ngan H Y S , Chan K Y K , Tam I Y S , Chiu P M , Ip P P C , Tam K F , Cheung A N Y
Published: February 2005

Aims : To assess, in tissue microarray (TMA), the proliferative activity of endometrial carcinoma using one of the minichromosome maintenance (MCM) proteins (MCM7), and to explore its potential value for prognosis. MCM proteins are essential for eukaryotic DNA replication and have recently been used to define the proliferative compartments in human tissues.

Methods and results : Immunohistochemistry for MCM7 and Ki67 was performed on TMAs constructed from 212 cases of endometrial carcinoma. MCM7 and Ki67 expression was quantified according to the extent of nuclear staining. An analysis was carried out of the association between MCM7 expression and that of Ki67 and the clinicopathological characteristics of endometrial carcinoma. MCM7 and Ki67 immunoreactivity was clearly evident in the nuclei of tumour cells. MCM7 and Ki67 labelling indices in endometrial carcinomas correlated with each other (P < 0.001). A significant correlation existed between the MCM7 labelling index and histological grade (P = 0.008) and patients' age at diagnosis (P < 0.001). Well‐differentiated carcinomas and younger patients had a lower MCM7 index. Poor survival was observed in patients with endometrial carcinoma with a high MCM7 index (P = 0.03) and MCM7 was found to be an independent prognostic factor by multivariate analysis (P = 0.04). The Ki67 labelling index correlated with histological grade (P = 0.01) but had no significant prognostic impact (P = 0.50).

Conclusions : In this TMA study on endometrial carcinoma, MCM7 was found to be a more reliable and useful marker than Ki67 in assessing tumour proliferation and in the prognosis of patients.
The expression of p53 and bcl‐2 in gastrointestinal stromal tumours is associated with anatomical site, and p53 expression is associated with grade and clinical outcome
Authors: Feakins R M
Published: February 2005

Aims : To compare the expression of p53 and bcl‐2 in gastrointestinal stromal tumours (GISTs) with anatomical site, National Institutes of Health (NIH) risk category (grade), pathological features, and clinical outcome.

Methods and results : The immunohistochemical expression of p53 and bcl‐2 in 105 GISTs (71 gastric, 20 small intestinal, four colonic, 10 rectal) was recorded. When all GISTs were assessed, there was p53 positivity in 28% and bcl‐2 positivity in 77%. Gastric tumours had a lower prevalence of p53 positivity (20%) than intestinal (40–50%). Rectal GISTs had the lowest prevalence of bcl‐2 positivity (20%) and gastric and small intestinal the highest (80% and 90%, respectively). In GISTs from all sites, p53 positivity was associated with size > 50 mm, epithelioid cell shape, nuclear atypia, mucosal invasion, and mitotic count > 5/50 high‐power fields. In gastric GISTs the associations were the same, apart from size and mitotic count. In GISTs from all sites and in gastric GISTs, p53 expression correlated with NIH risk category. When GISTs from all sites were subjected to univariate survival analysis, an adverse outcome was associated with p53 positivity, NIH risk category, and several established prognostic factors. When gastric GISTs were assessed, the associations were similar although size was not prognostic. In multivariate survival analysis, p53 expression was independently prognostic for gastric GISTs in some models, while it was never independently prognostic for GISTs from all sites. Whether all GISTs or gastric GISTs were assessed, bcl‐2 showed no association with clinical outcome or risk category.

Conclusions : Anatomical site influences p53 and bcl‐2 expression in GISTs. p53 expression is associated with NIH risk category, various pathological features, and clinical outcome, and may be independently prognostic for gastric GISTs. Bcl‐2 expression has no prognostic value.
Expression of S100 proteins in normal human tissues and common cancers using tissue microarrays: S100A6, S100A8, S100A9 and S100A11 are all overexpressed in common cancers
Authors: Cross S S , Hamdy F C , Deloulme J C , Rehman I
Published: February 2005

Aims : To survey the expression of members of the S100 family of calcium‐binding proteins in normal human tissues and common cancers using tissue microarrays. S100A6, S100A8, S100A9 and S100A11 have all been suggested to have potential roles in carcinogenesis and tumour progression but their expression has not been described in a wide range of human tissues and tumours.

Methods and results : A custom‐made tissue array, containing 291 tissue cores representing 28 tissue types and 21 tumour types, was used to produce sections that were immunostained for S100A2, S100A6, S100A8, S100A9, S100A11, calbindin 1, calbindin 2, S100B and parvalbumin. S100A6, S100A8 and S100A9 were expressed in 32%, 12% and 28% of breast cancers, respectively. There was a translocation of S100A11 expression from exclusively nuclear in normal tissues to cytoplasmic and nuclear in all common cancers.

Conclusions : S100A6, S100A8, S100A9 and S100A11 are all expressed in common cancers, especially breast cancer. In addition, S100A11 undergoes a nucleocytoplasmic translocation which may have a direct influence on the proliferation of the cancer cells.