bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodegradable foams of poly(lactic acid)/starch. II. Cellular structure and water resistance
Authors: Zhang Jian‐Feng , Sun Xiuzhi
Published: August 2007

Biodegradable foams were prepared with poly(lactic acid) and starch by extrusion. The compression modulus of the foams was negatively related to the foam bulk density. The foam consists of both open‐ and close‐cell structures. The presence of PLA significantly improved the water resistance of the foam, and significantly improved the foam recovery capacity, especially in high‐moisture conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Neoadjuvant chemotherapy for operable breast cancer
Authors: Mieog J S D , van der Hage J A , van de Velde C J H
Published: August 2007

Background

Neoadjuvant chemotherapy for early breast cancer can avoid mastectomy by shrinkage of tumour volume. This review assesses the effectiveness of neoadjuvant chemotherapy on clinical outcome.

Methods

All randomized trials comparing neoadjuvant and adjuvant chemotherapy for early breast cancer were reviewed systematically and meta-analyses were performed.

Results

Fourteen studies randomizing 5500 women were eligible for analysis. Overall survival was equivalent in both groups. In the neoadjuvant group, the mastectomy rate was lower (relative risk 0·71 (95 per cent confidence interval (c.i.) 0·67 to 0·75)) without hampering local control (hazard ratio 1·12 (95 per cent c.i. 0·92 to 1·37)). Neoadjuvant chemotherapy was associated fewer adverse effects.

Conclusion

Neoadjuvant chemotherapy is an established treatment option for early breast cancer.
Young age colorectal cancer and identification of hereditary non-polyposis colorectal cancer cohorts
Authors: Bisgaard M L
Published: August 2007

Prophylaxis advocated
Retroperitoneal sarcoma
Authors: Thomas J M
Published: August 2007

Poor prognosis and difficult to treat
Corporate greening and changing regulatory regimes: the UK water industry
Authors: Schaefer Anja
Published: August 2007

This article looks at the relationship between economic regulation, environmental regulation, company strategy and the environment in the UK water and sewerage industry. The regulatory field in this industry, following privatization in 1989, is highly complex and interdependent. The paper presents three case studies of company interpretation of and response to changes in this regulatory field, focusing particularly on the third review by the economic regulator, in 1999, which involved a reduction of the prices companies were allowed to charge their customers. This had significant but complex repercussions for environmental strategy and management in the companies, with different impacts on mandatory and non‐mandatory activities. It also showed in relief the opportunities for building coalitions between companies and the environmental regulator, both in general terms and revolving around specific, local environmental issues and schemes. Companies' strategic direction was also found to have an impact on their response to the regulatory review. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Caricature video
Authors: Lee Eun‐Jung , Kwon Ji‐yong , Lee In‐Kwon
Published: August 2007

We make moving caricatures from videos on human faces. Using training images, we created a 3D model of an average face. This allows us to transform the image in each frame of an input video, so that it is seen from the front. Then we apply 2D exaggeration rules to caricature each face. Finally, we rotate the face in each frame back to its original position. A panel of viewers gave positive scores to a series of test videos. Copyright © 2007 John Wiley & Sons, Ltd.
Design and Synthesis of Cyclopeptide Analogues of the Potent Histone Deacetylase Inhibitor FR235222
Authors: Gomez‐Paloma Luigi , Bruno Ines , Cini Elena , Khochbin Saadi , Rodriquez Manuela , Taddei Maurizio , Terracciano Stefania , Sadoul Karin
Published: August 2007

Various structurally modified analogues of FR235222 (1), a natural tetrapeptide inhibitor of mammalian histone deacetylases, were prepared in a convergent approach. The design of the compounds was aimed to investigate the effect of structural modifications of the tetrapeptide core involved in enzyme binding in order to overcome some synthetic difficulties connected with the natural product 1. The modifications introduced could also help identify key structural features involved in the mechanism of action of these compounds. The prepared molecules were subjected to in vitro pharmacological tests, and their potency was tested on cultured cells. Two of the components of the array were found to be more potent than the parent compound 1 and almost as efficient as trichostatin A (TSA). These results demonstrate that it is possible to synthesize highly active cyclic tetrapeptides using commercially available amino acids (with the exception of 2‐amino‐8‐oxodecanoic acid, Ahoda). The nature of the residue in the second position of the cyclic peptide and the stereochemistry of the Ahoda tail are important for the inhibitory activity of this class of cyclic tetrapeptide analogues.
Analysis of connexin subunits required for the survival of vestibular hair cells
Authors: Qu Yan , Tang Wenxue , Dahlke Ian , Ding Dalian , Salvi Richard , Söhl Goran , Willecke Klaus , Chen Ping , Lin Xi
Published: August 2007

Mutations in connexin (Cx) genes are responsible for a large proportion of human inherited prelingual deafness cases. The most commonly found human Cx mutations are either Cx26 or Cx30 deletions. Histological observations made in the organ of Corti of homozygous Cx26 and Cx30 gene knockout mice show that cochlear hair cells degenerate after the onset of hearing. However, it is unclear whether vestibular hair cells undergo similar degeneration in connexin knockout mice. To address this question, we first examined expression patterns of Cx26 and Cx30 in the saccule, utricle, and ampulla by immunolabeling. In wild‐type mice, Cx26 and Cx30 immunoreactivity was found extensively in vestibular supporting cells and connective tissue cells, and the two Cxs were co‐localized in most gap junction (GJ) plaques. Targeted deletion of the Cx30 gene, which caused little change in Cx26 expression pattern, resulted in a significant and age‐related loss of vestibular hair cells only in the saccule. dUTP nick end labeling (TUNEL) staining also revealed on‐going apoptosis specifically in saccular hair cells of Cx30−/− mice. These results indicated that hair cell survival in the utricle and ampulae does not require Cx30. Importantly, over‐expressing the Cx26 gene from a modified bacterial artificial chromosome in the Cx30−/− background rescued the saccular hair cells. These results suggest that it is the reduction in the total amount of GJs rather than the specific loss of Cx30 that underlies saccular hair cell death in Cx30−/− mice. Hybrid GJs co‐assembled from Cx26 and Cx30 were not essential for the survival of saccular hair cells. J. Comp. Neurol. 504:499–507, 2007. © 2007 Wiley‐Liss, Inc.
Deletion of EphA4 enhances deafferentation‐induced ipsilateral sprouting in auditory brainstem projections
Authors: Hsieh Candace Y. , Hong Cindy T. , Cramer Karina S.
Published: August 2007

Axonal selection of ipsilateral and/or contralateral targets is essential for integrating bilateral sensory information and for coordinated movement. The molecular processes that determine ipsilateral and contralateral target choice are not fully understood. We examined this target selection in the developing auditory brainstem. Ventral cochlear nucleus (VCN) axons normally project to the medial nucleus of the trapezoid body (MNTB) only on the contralateral side. However, after unilateral removal of cochlear input in neonates, we found that axons from the unoperated VCN sprout and project to MNTB bilaterally. We found that EphA4 is expressed in the mouse auditory brainstem during development and during a sensitive period for ipsilateral sprouting, so we hypothesized that deletion of the Eph receptor EphA4 would impair target selection in these auditory pathways. Lipophilic dyes were used to evaluate quantitatively the brainstem projections in wild‐type and EphA4‐null mice. VCN‐MNTB projections in EphA4‐null mice were strictly contralateral, as in wild‐type mice. However, after deafferentation, EphA4‐null mice had a significant, threefold increase in the proportion of axons from the intact VCN that sprouted into ipsilateral MNTB compared with wild‐type mice. Heterozygous mice had a twofold increase in these projections. These results demonstrate that EphA4 influences auditory brainstem circuitry selectively in response to deafferentation. Although this axon guidance molecule is not by itself necessary for appropriate target choice during normal development, it is a strong determinant of ipsilateral vs. contralateral target choice during deafferentation‐induced plasticity. J. Comp. Neurol. 504:508–518, 2007. © 2007 Wiley‐Liss, Inc.
Islam and CSR: a study of the compatibility between the tenets of Islam, the UN Global Compact and the development of social, human and natural capital
Authors: Zinkin John
Published: August 2007

Previous research has found that Muslims score elements that are assumed to matter in determining socially responsible business behaviour less highly than people of other religions. This paper looks at whether the tenets of Islam are the reason for this lower score by comparing and contrasting the UN Global Compact's ten principles with those of Islam in the affected areas. In so doing, the paper reconstructs the principles according to their impact on social, human and natural capital and explores whether Islam is supportive of responsible behaviour in these three areas. The paper concludes that, with the possible exception of Islam's focus on personal responsibility and non‐recognition of the corporation as a legal person, which could undermine the concept of corporate responsibility, there is no divergence between the tenets of the religion and the principles of the UN Global Compact. Focusing on this convergence of values could help avert the threatened ‘clash of civilizations’. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Cyclosporin‐A treatment attenuates delayed cytoskeletal alterations and secondary axotomy following mild axonal stretch injury
Authors: Staal J.A. , Dickson T.C. , Chung R.S. , Vickers J.C.
Published: August 2007

Following central nervous system trauma, diffuse axonal injury and secondary axotomy result from a cascade of cellular alterations including cytoskeletal and mitochondrial disruption. We have examined the link between intracellular changes following mild/moderate axonal stretch injury and secondary axotomy in rat cortical neurons cultured to relative maturity (21 days in vitro). Axon bundles were transiently stretched to a strain level between 103% and 106% using controlled pressurized fluid. Double‐immunohistochemical analysis of neurofilaments, neuronal spectrin, α‐internexin, cytochrome‐c, and ubiquitin was conducted at 24‐, 48‐, 72‐, and 96‐h postinjury. Stretch injury resulted in delayed cytoskeletal damage, maximal at 48‐h postinjury. Accumulation of cytochrome‐c and ubiquitin was also evident at 48 h following injury and colocalized to axonal regions of cytoskeletal disruption. Pretreatment of cultures with cyclosporin‐A, an inhibitor of calcineurin and the mitochondrial membrane transitional pore, reduced the degree of cytoskeletal damage in stretch‐injured axonal bundles. At 48‐h postinjury, 20% of untreated cultures demonstrated secondary axotomy, whereas cyclosporin A‐treated axon bundles remained intact. By 72‐h postinjury, 50% of control preparations and 7% of cyclosporin A‐treated axonal bundles had progressed to secondary axotomy, respectively. Statistical analyses demonstrated a significant (p < 0.05) reduction in secondary axotomy between treated and untreated cultures. In summary, these results suggest that cyclosporin‐A reduces progressive cytoskeletal damage and secondary axotomy following transient axonal stretch injury in vitro. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Coemergence of regularity and complexity during neural network development
Authors: Fuchs E. , Ayali A. , Robinson A. , Hulata E. , Ben‐Jacob E.
Published: August 2007

With the growing recognition that rhythmic and oscillatory patterns are widespread in the brain and play important roles in all aspects of the function of our nervous system, there has been a resurgence of interest in neuronal synchronized bursting activity. Here, we were interested in understanding the development of synchronized bursts as information‐bearing neuronal activity patterns. For that, we have monitored the morphological organization and spontaneous activity of neuronal networks cultured on multielectrode‐arrays during their self‐executed evolvement from a mixture of dissociated cells into an active network. Complex collective network electrical activity evolved from sporadic firing patterns of the single neurons. On the system (network) level, the activity was marked by bursting events with interneuronal synchronization and nonarbitrary temporal ordering. We quantified these individual‐to‐collective activity transitions using newly‐developed system level quantitative measures of time series regularity and complexity. We found that individual neuronal activity before synchronization was characterized by high regularity and low complexity. During neuronal wiring, there was a transient period of reorganization marked by low regularity, which then leads to coemergence of elevated regularity and functional (nonstochastic) complexity. We further investigated the morphology‐activity interplay by modeling artificial neuronal networks with different topological organizations and connectivity schemes. The simulations support our experimental results by showing increased levels of complexity of neuronal activity patterns when neurons are wired up and organized in clusters (similar to mature real networks), as well as network‐level activity regulation once collective activity forms. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Regulation of actomyosin contractility by PI3K in sensory axons
Authors: Orlova Irina , Silver Lee , Gallo Gianluca
Published: August 2007

Phosphatidylinositol 3‐kinase (PI3K) activity is known to be required for the extension of embryonic sensory axons. Inhibition of PI3K has also been shown to mediate axon retraction and growth cone collapse in response to semaphorin 3A. However, the effects of inhibiting PI3K on the neuronal cytoskeleton are not well characterized. We have previously reported that semaphorin 3A‐induced axon retraction involves activation of myosin II, the formation of an intra‐axonal F‐actin bundle cytoskeleton, and blocks the formation of F‐actin patches that serve as precursors to filopodial formation in axons. We now report that inhibition of PI3K results in activation of myosin II in axons. Inhibition of myosin II activity, or its upstream regulatory kinase RhoA‐kinase, blocked axon retraction induced by inhibition of PI3K. In addition, inhibition of PI3K also induced intra‐axonal F‐actin bundles, which likely serve as a substratum for myosin II‐based force generation during axon retraction. In axons, filopodia are formed from axonal F‐actin patch precursors. Analysis of axonal F‐actin patch formation in eYFP‐actin expressing neurons revealed that inhibition of PI3K blocked formation of axonal F‐actin patches, and thus filopodial formation. These data provide insights into the regulation of the neuronal cytoskeleton by PI3K and are consistent with the notion that decreased levels of PI3K activity mediate axon retraction and growth cone collapse in response to semaphorin 3A. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
Activation of retinoic acid receptor‐α favours regulatory T cell induction at the expense of IL‐17‐secreting T helper cell differentiation
Authors: Schambach Felix , Schupp Michael , Lazar Mitchell A. , Reiner Steven L.
Published: August 2007

Autoimmunity is thought to reflect an imbalance between regulatory T helper lymphocytes (Treg) and pathogenic, IL‐17‐secreting T helper (Th17) cells. Induction of both adaptive Treg and Th17 cells requires signalling from TGF‐β. We now show that, in the context of TGF‐β signalling, all‐trans retinoic acid (ATRA) leads to increased induction of CD4+ T cells expressing the Treg specification factor forkhead box protein P3 (FoxP3) and decreased frequency of cells expressing IL‐17, even in the presence of IL‐6. Using a specific agonist and antagonist, as well as retroviral over‐expression, we also provide evidence that the effects of ATRA are likely to be at least partially mediated by the nuclear retinoic acid receptor‐α (RARα). These findings indicate that signalling through a specific nuclear retinoic acid receptor can favour the decision to adopt the Treg fate at the expense of Th17 fate. Specific agonists of RARα could, therefore, be considered candidates for the treatment of autoimmunity.
Axial Coordination of Porphyrinatocobalt(II) Complexes with Bis(pyridinolato)silicon(IV) Phthalocyanines
Authors: Leng Xuebing , Ng Dennis K. P.
Published: August 2007

Treatment of dichlorosilicon(IV) phthalocyanine with 3‐ or 4‐hydroxypyridine in the presence of pyridine in toluene gave the corresponding bis(pyridinolato)silicon(IV) phthalocyanine complexes SiPc(3‐OPy)2 (1) or SiPc(4‐OPy)2 (2), respectively, which were spectroscopically and structurally characterized. As shown by electronic absorption spectroscopy, these compounds axially bind to meso‐tetraphenylporphyrinatocobalt(II) [Co(TPP) (3)] and meso‐tetrakis(3,5‐di‐tert‐butylphenyl)porphyrinatocobalt(II) [Co(TBPP) (4)] with the two pyridyl ligands forming the corresponding mixed phthalocyanine–porphyrin triads. The binding constants K1 between the 4‐pyridyl phthalocyanine 2 and the porphyrinatocobalt(II) complexes (1.1–1.2 × 104 M–1) are about threefold higher than those for the 3‐pyridyl counterpart 1. The heterodyads 2·3 and 2·4 were isolated by column chromatography and characterized by mass and absorption spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Water‐Soluble Phenanthroline Complexes of Rhodium, Iridium and Ruthenium for the Regeneration of NADH in the Enzymatic Reduction of Ketones
Authors: Canivet Jérôme , Süss‐Fink Georg , Štěpnička Petr
Published: August 2007

The nicotinamide coenzyme NADH, consumed in enantioselective reduction of ketones catalysed by alcohol dehydrogenases, needs to be regenerated in order to maintain enzymatic activity. We therefore studied the catalytic potential of the cationic complexes [(η5‐C5Me5)Rh(N∩N)Cl]+ (1: N∩N = 1,10‐phenanthroline; 2: N∩N = 5‐nitro‐1,10‐phenanthroline; 3: N∩N = 5‐amino‐1,10‐phenanthroline), [(η5‐C5Me5)Ir(N∩N)Cl]+ (4: N∩N = 5‐nitro‐1,10‐phenanthroline) and [(η6‐C6Me6)Ru(N∩N)Cl]+ (5: N∩N = 5‐nitro‐1,10‐phenanthroline), isolated as the water‐soluble chloride salts, for transfer hydrogenation of NAD+ to give NADH in aqueous solution. The best results were obtained with rhodium complex 1, which gave catalytic turnover frequencies up to 2000 h–1 in aqueous solution at pH 7 and 60 °C with sodium formate as the hydrogen source. When this NADH‐regenerating catalytic system is combined with NADH‐dependent enzymes, it is possible to chemoenzymatically reduce prochiral ketones such as acetophenone or 4‐phenylbutan‐2‐one with high enantioselectivity. Combination of horse liver alcohol dehydrogenase (HLADH) or alcohol dehydrogenase from Rhodococcus sp. (S‐ADH) with 1/formate as the NADH‐regenerating system resulted in ee values up to 98 %, depending on the nature of the substrate and the enzyme. In order to explain the different catalytic activities, the electrochemical behaviour of complexes 1–5 has been studied.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis and Characterization of a New Guanidine–Borane Complex and a Dinuclear Boron(II) Hydride with Bridging Guanidinate Ligands
Authors: Ciobanu Oxana , Roquette Pascal , Leingang Simone , Wadepohl Hubert , Mautz Jürgen , Himmel Hans‐Jörg
Published: August 2007

We report the synthesis and structural characterization of the new monomeric borane complex H3B·hppH (hppH = 1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine), which represents the first example of a structurally characterized 1:1 complex between hppH and a group 13 element hydride. Significant intramolecular and, in the crystalline phase, intermolecular H···H contacts are established in this complex. It is shown that the complex can be used as a precursor to new dinuclear boron(II) compounds featuring a B–B single bond. Thus H2 elimination followed by dimerization of H3B·hppH leads to [(hpp)BH]2 with two bridging hpp units. The structural details derived from X‐ray diffraction measurements are reported.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Behavioral regulation: factor analysis and application of the Behavioral Dyscontrol Scale in dementia and mild cognitive impairment
Authors: Hall James R. , Harvey Michelle B.
Published: August 2007

Background

Executive dysfunction is a hallmark of both Dementia of the Alzheimer's Type (AD) and Vascular Dementia (VaD). A complete neuropsychological battery contains measures of executive function, but the focus tends to be on cognitive processes with verbal or written output. The Behavioral Dyscontrol Scale (BDS) is purported to be a measure of executive function that addresses control over voluntary motor behavior. Previous factor analyses revealed three‐factor solutions using a variety of patient populations. Our goals were to examine the factor structure in a sample of geriatric outpatients and to apply that factor structure to detect possible differences between AD, VaD, amnestic Mild Cognitive Impairment (MCI), non‐amnestic MCI, and normal controls.

Methods

An exploratory factor analysis was performed on 260 outpatient evaluations from 2002–2006. Only the seven items requiring motor responses were included.

Results

A two‐factor solution emerged. We named the factors Motor Problem‐Solving and Simple Motor Repetitive Behaviors. For the first factor, the AD and VaD groups differed from the MCI groups and normal controls, but did not differ from each other. There were no differences between the control, amnestic MCI, and non‐amnestic MCI groups. There were no differences between the groups for the second factor.

Conclusion

It was concluded that voluntary control of behavior that requires problem‐solving for complex tasks may help differentiate dementia from mild cognitive impairment and normal aging. Copyright © 2007 John Wiley & Sons, Ltd.
HTR2C haplotypes and antipsychotics‐induced weight gain: X‐linked multimarker analysis
Authors: De Luca Vincenzo , Müller Daniel J. , Hwang Rudi , Lieberman Jeffrey A. , Volavka Jan , Meltzer Herbert Y. , Kennedy James L.
Published: August 2007

The 5HT2C receptor (HTR2C) has been hypothesized to represent an important modulator in feeding behavior. Evidence was based on the observation that knock‐out mice for the HTR2C receptor gene develop obesity and that many antipsychotics (AP) with potent HTR2C antagonism may induce weight gain in susceptible individuals. Pharmacogenetic studies focusing either on the Cys23Ser polymorphism or on the −759C/T promoter polymorphism of the X‐linked HTR2C receptor gene revealed significant findings for the −759C/T polymorphism, however, no study has performed haplotype analyses for both polymorphisms.

Methods

We analyzed three functional polymorphisms (Cys23Ser, −759C/T, and (GT)12–18/(CT) 4–5) of the HTR2C in 139 schizophrenic patients mainly treated with clozapine. Weight gain was assessed over a time course of 6–14 weeks (mean 8.2 weeks).

Results

Single marker and haplotype analysis revealed no significant associations with AP‐induced weight gain. The haplotype Long‐C‐Ser was protective against weight gain, but the number of subjects available for that analysis was small.

Conclusions

Our pilot study did not detect any significant haplotype conferring risk for antipsychotic‐induced weight gain although the statistical model took into account the X‐linked heterogeneity and did correct for confounding factors (i.e., ethnicity, medications, clinical response, time of assessment). Copyright © 2007 John Wiley & Sons, Ltd.
Mobility of major ions and nutrients in the unsaturated zone during paddy cultivation: a field study and solute transport modelling approach
Authors: Rajmohan N. , Elango L.
Published: August 2007

Study of the movement of water and solute within soil profiles is important for a number of reasons. Accumulation of prominent contaminants from agricultural chemicals in the unsaturated zone over the years is a major concern in many parts of the world. As a result, the unsaturated zone has been a subject of great research interest during the past decade. Hence, an intensive field study was conducted in a part of Palar and Cheyyar river basins to understand the variation of major ions and nutrients in the soil zone during paddy cultivation. The chloride and nitrate data were used to model the movement of these chemicals in the unsaturated zone using the HYDRUS‐2D model. The field study shows that fertilizer application and irrigation return flow increases the major ions and nutrients concentration in the unsaturated zone. Further, the nutrient concentrations are regulated by plant uptake, fertilizer application and infiltration rate. Additionally, denitrification and soil mineralization processes also regulate the nitrogen concentration in the unsaturated zone. The solute transport modelling study concluded that the simulated results match reasonably with the observed trends. Simulated concentrations of chloride and nitrate for a 5‐year period indicate that the concentrations of these ions fluctuate in a cyclic manner (from 60 to 68 mg l−1 and from 3·4 to 3·5 mg l−1 respectively in groundwater) with no upward and downward trend. The influence of excessive fertilizer application on groundwater was also modelled. The model predicts an increase of about 17 mg l−1 of chloride and 2·3 mg l−1 of nitrogen in the groundwater of this area when the application of fertilizers is doubled. The model indicates that the present level of use of agrochemicals is no threat to the groundwater quality. Copyright © 2007 John Wiley & Sons, Ltd.
Fine sediment delivery and transfer in lowland catchments: modelling suspended sediment concentrations in response to hydrological forcing
Authors: Jarritt N. P. , Lawrence D. S. L.
Published: August 2007

Fine sediment delivery to and storage in stream channel reaches can disrupt aquatic habitats, impact river hydromorphology, and transfer adsorbed nutrients and pollutants from catchment slopes to the fluvial system. This paper presents a modelling tool for simulating the time‐dependent response of the fine sediment system in catchments, using an integrated approach that incorporates both land phase and in‐stream processes of sediment generation, storage and transfer. The performance of the model is demonstrated by applying it to simulate in‐stream suspended sediment concentrations in two lowland catchments in southern England, the Enborne and the Lambourn, which exhibit contrasting hydrological and sediment responses due to differences in substrate permeability. The sediment model performs well in the Enborne catchment, where direct runoff events are frequent and peak suspended sediment concentrations can exceed 600 mg l−1. The general trends in the in‐stream concentrations in the Lambourn catchment are also reproduced by the model, although the observed concentrations are low (rarely exceeding 50 mg l−1) and the background variability in the concentrations is not fully characterized by the model. Direct runoff events are rare in this highly permeable catchment, resulting in a weak coupling between the sediment delivery system and the catchment hydrology. The generic performance of the model is also assessed using a generalized sensitivity analysis based on the parameter bounds identified in the catchment applications. Results indicate that the hydrological parameters contributing to the sediment response include those controlling (1) the partitioning of runoff between surface and soil zone flows and (2) the fractional loss of direct runoff volume prior to channel delivery. The principal sediment processes controlling model behaviour in the simulations are the transport capacity of direct runoff and the in‐stream generation, storage and release of the fine sediment fraction. The in‐stream processes appear to be important in maintaining the suspended sediment concentrations during low flows in the River Enborne and throughout much of the year in the River Lambourn. Copyright © 2007 John Wiley & Sons, Ltd.
Water balance of tropical rainforest canopies in north Queensland, Australia
Authors: McJannet David , Wallace Jim , Fitch Peter , Disher Mark , Reddell Paul
Published: August 2007

The water balance of four different rainforest types in the Wet Tropics region of north Queensland is inferred from measurements of canopy hydrological components undertaken for periods between 391 to 657 days. These measurements of rainfall, cloud interception, stem‐flow, throughfall, canopy interception and transpiration have revealed considerable differences in the canopy water balance of different locations as a result of forest structural differences, altitude, exposure and climate. Cloud interception is a significant extra input of water to forests at high altitude sites (>1000 m) and varies between 7 and 29% of the total water input. At coastal and lower montane rainforests annual total evaporation is consistently around 50% of the total water input, but in upper montane cloud forest this drops dramatically to only 13% of the water input. At all sites actual evaporation is greater than potential evaporation for most of the year and on an annual basis exceeds potential by between 2 and 53%. The source of this additional energy is uncertain, but is likely to come from advection. Annual interception at all the rainforest sites was greater than annual transpiration, with transpiration dominating in the dry season and interception dominating in the wet season. All of the rainforests have a large annual net water balance to sustain runoff and recharge. Towards the end of the dry season runoff and recharge can cease in coastal lowland and lower mountain forests and they may have to draw on soil moisture and/or ground water at this time. In contrast, upper montane cloud forests have a positive net water balance throughout the year and are therefore an important source of dry season river flows. Furthermore, their exceptionally large annual runoff (∼6500 mm year−1) is a major source of downstream water. Copyright © 2007 John Wiley & Sons, Ltd.
The influence of climate change on suspended sediment transport in Danish rivers
Authors: Thodsen H. , Hasholt B. , Kjærsgaard J. H.
Published: August 2007

The HIRHAM regional climate model suggests an increase in temperature in Denmark of about 3 °C and an increase in mean annual precipitation of 6–7%, with a larger increase during winter and a decrease during summer between a control period 1961–1990 and scenario period 2071–2100. This change of climate will affect the suspended sediment transport in rivers, directly through erosion processes and increased river discharges and indirectly through changes in land use and land cover. Climate‐change‐induced changes in suspended sediment transport are modelled for five scenarios on the basis of modelled changes in land use/land cover for two Danish river catchments: the alluvial River Ansager and the non‐alluvial River Odense. Mean annual suspended sediment transport is modelled to increase by 17% in the alluvial river and by 27% in the non‐alluvial for steady‐state scenarios. Increases by about 9% in the alluvial river and 24% in the non‐alluvial river were determined for scenarios incorporating a prolonged growing season for catchment vegetation. Shortening of the growing season is found to have little influence on mean annual sediment transport. Mean monthly changes in suspended sediment transport between − 26% and + 68% are found for comparable suspended sediment transport scenarios between the control and the scenario periods. The suspended sediment transport increases during winter months as a result of the increase in river discharge caused by the increase in precipitation, and decreases during summer and early autumn months. Copyright © 2007 John Wiley & Sons, Ltd.
Using stochastic state‐space modelling to specify and reduce hydrograph error
Authors: Collier C. G. , Robbins G. L.
Published: August 2007

A Bayesian post‐processor is used to generate a representation of the likely hydrograph forecast flow error distribution using raingauge and radar input to a stochastic catchment model and its deterministic equivalent. A hydrograph ensemble is so constructed. Experiments are analysed using the model applied to the River Croal in north‐west England. It is found that for rainfall input to the model having errors less than 3mm h−1, corresponding to about a 15% error in peak flow, the stochastic model outperforms the deterministic model. The range of hydrographs associated with the different model simulations and the measured hydrographs are compared. The significant improvement possible using a stochastic approach is demonstrated for a specific case study, although the mean hydrograph derived using the stochastic model has an error range associated with it. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrologic comparison between a forested and a wetland/lake dominated watershed using SWAT
Authors: Wu Kangsheng , A. Johnston Carol
Published: August 2007

The Soil and Water Assessment Tool (SWAT) is a physically‐based hydrologic model developed for agricultural watersheds, which has been infrequently validated for forested watersheds, particularly those with deep overwinter snow accumulation and abundant lakes and wetlands. The goal of this study was to determine the applicability of SWAT for modelling streamflow in two watersheds of the Ontonagon River basin of northern Michigan which differ in proportion of wetland and lake area. The forest‐dominated East Branch watershed contains 17% wetland and lake area, whereas the wetland/lake‐dominated Middle Branch watershed contains 26% wetland and lake area. The specific objectives were to: (1) calibrate and validate SWAT models for the East Branch and Middle Branch watersheds to simulate monthly stream flow, and (2) compare the effects of wetland and lake abundance on the magnitude and timing of streamflow. Model calibration and validation was satisfactory, as determined by deviation of discharge D and Nash and Sutcliffe coefficient values E that compared simulated monthly mean discharge versus measured monthly mean discharge. Streamflow simulation discrepancies occurred during summer and fall months and dry years. Several snow melting parameters were found to be critical for the SWAT simulation: TIMP (snow temperature lag factor) and SMFMX and SMFMN (melting factors). Snow melting parameters were not transferable between adjacent watersheds. Differences in seasonal pattern of long‐term monthly streamflow were found, with the forest‐dominated watershed having a higher peak flow during April but a lower flow during the remainder of the year in comparison to the wetland and lake‐dominated watershed. The results suggested that a greater proportion of wetland and lake area increases the capacity of a watershed to impound surface runoff and to delay storm and snow melting events. Representation of wetlands and lakes in a watershed model is required to simulate monthly stream flow in a wetland/lake‐dominated watershed. Copyright © 2007 John Wiley & Sons, Ltd.
Estimating suspended sediment concentrations from turbidity measurements and the calibration problem
Authors: Minella Jean P. G. , Merten Gustavo H. , Reichert José M. , Clarke Robin T.
Published: August 2007

In situ turbidity meters are being increasingly used to generate continuous records of suspended sediment concentration in rivers. However, the usefulness of the information obtained depends heavily on the existence of a close relationship between fluctuations in suspended sediment concentration and turbidity and the calibration procedure that relates suspended sediment concentration to the turbidity meter's signal. This study assesses the relationship between suspended sediment concentration and turbidity for a small (1·19 km2) rural catchment in southern Brazil and evaluates two calibration methods by comparing the estimates of suspended sediment concentration obtained from the calibrated turbidity readings with direct measurements obtained using a USDH 48 suspended sediment sampler. With the first calibration method, the calibration relationship is derived by relating the turbidity readings to simultaneous measurements of concentration obtained from suspended sediment samples collected from the vicinity of the turbidity probe during flood events. With the second method, the calibration is based on the readings obtained from the turbidity meter when the probe immersed in samples of known concentration prepared using soils collected from the catchment. Overall, there was a close link between fluctuations in suspended sediment concentration and turbidity in the stream at the outlet of the catchment, and the estimates of sediment concentration obtained using the first calibration method corresponded closely with the conventionally measured sediment concentrations. However, use of the second calibration method introduced appreciable errors. When the estimated sediment concentrations were compared with the measured values, the mean errors were ± 122 mg l−1 and + 601 mg l−1 for the first and second calibration procedures respectively. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling study on the impact of deep building foundations on the groundwater system
Authors: Ding Guoping , Jiao Jiu J. , Zhang Dongxiao
Published: August 2007

Coastal areas are usually the preferred place of habitation for human beings. Anthropogenic activities such as the construction of high‐rise buildings and underground transport systems usually require extensive deep foundations and ground engineering works, which may unintentionally modify the coastal groundwater system because the construction materials of foundations are usually of low hydraulic conductivity. In this paper, the impact of these building foundations on the groundwater regime is studied using hypothetical flow and transport models. Various possible realizations of foundation distributions are generated using stochastic parameters derived from a topographical map of an actual coastal area in Hong Kong. The effective hydraulic conductivity is first calculated for different realizations and the results show that the effective hydraulic conductivity can be reduced significantly. Then a hypothetical numerical model based on FEFLOW is set up to study the change of hydraulic head, groundwater discharge, and saltwater‐fresh water interface. The groundwater level and flow are modified to various degrees, depending on the foundations percentage and the distribution pattern of the buildings. When the foundations percentage is high and the building foundations are aggregated, the hydraulic head is raised significantly and the originally one‐dimensional groundwater flow field becomes complicated. Seaward groundwater discharge will be reduced and some groundwater may become seepage through the ground surface. The transport model shows that, after foundations are added, overall the seawater and fresh groundwater interface moves landward, so extensive foundations may induce seawater intrusion. It is believed that the modification of the coastal groundwater system by building foundations may have engineering and environmental implications, such as submarine groundwater discharge, foundation corrosion, and slope stability. Copyright © 2007 John Wiley & Sons, Ltd.
Climatic control on river discharge simulations, Zackenberg River drainage basin, northeast Greenland
Authors: Mernild Sebastian H. , Hasholt Bent , Liston Glen E.
Published: August 2007

A spatially distributed, physically based, hydrologic modeling system (MIKE SHE) was applied to quantify intra‐ and inter‐annual discharge from the snow and glacierized Zackenberg River drainage basin (512 km2; 20% glacier cover) in northeast Greenland. Evolution of snow accumulation, distribution by wind‐blown snow, blowing‐snow sublimation, and snow and ice surface melt were simulated by a spatially distributed, physically based, snow‐evolution modelling system (SnowModel) and used as input to MIKE SHE. Discharge simulations were performed for three periods 1997–2001 (calibration period), 2001–2005 (validation period), and 2071–2100 (scenario period). The combination of SnowModel and MIKE SHE shows promising results; the timing and magnitude of simulated discharge were generally in accordance with observations (R2 = 0·58); however, discrepancies between simulated and observed discharge hydrographs do occur (maximum daily difference up to 44·6 m3 s−1 and up to 9% difference between observed and simulated cumulative discharge). The model does not perform well when a sudden outburst of glacial dammed water occurs, like the 2005 extreme flood event. The modelling study showed that soil processes related to yearly change in active layer depth and glacial processes (such as changes in yearly glacier area, seasonal changes in the internal glacier drainage system, and the sudden release of glacial bulk water storage) need to be determined, for example, from field studies and incorporated in the models before basin runoff can be quantified more precisely. The SnowModel and MIKE SHE model only include first‐order effects of climate change. For the period 2071–2100, future IPCC A2 and B2 climate scenarios based on the HIRHAM regional climate model and HadCM3 atmosphere–ocean general circulation model simulations indicated a mean annual Zackenberg runoff about 1·5 orders of magnitude greater (around 650 mmWE year−1) than from today 1997–2005 (around 430 mmWE year−1), mainly based on changes in negative glacier net mass balance. Copyright © 2007 John Wiley & Sons, Ltd.
Electrospun‐modified nanofibrous scaffolds for the mineralization of osteoblast cells
Authors: Venugopal J. , Low Sharon , Choon Aw Tar , Kumar A. Bharath , Ramakrishna S.
Published: August 2007

Biocompatible polycaprolactone (PCL) and hydroxyapatite (HA) were fabricated into nanofibrous scaffolds for the mineralization of osteoblasts in bone tissue engineering. PCL and PCL/HA nanofibrous surface were modified using oxygen plasma treatment and showing 0° contact angle for the adhesion and mineralization of osteoblast cells. The fiber diameter, pore size and porosity of nanofibrous scaffolds were estimated to be 220–625 nm, 3–20 μm, and 87–92% respectively. The ultimate tensile strength of PCL was about 3.37 MPa and PCL/HA was 1.07 MPa to withstand the long term culture of osteoblasts on nanofibrous scaffolds. Human fetal osteoblast cells (hFOB) were cultured on PCL and PCL/HA surface modified and unmodified nanofibrous scaffolds. The osteoblast proliferation rate was significantly (p < 0.001) increased in surface‐modified nanofibrous scaffolds. FESEM showed normal phenotypic cell morphology and mineralization occurred in PCL/HA nanofibrous scaffolds, HA acting as a chelating agent for the mineralization of osteoblast to form bone like apatite for bone tissue engineering. EDX and Alizarin Red‐S staining indicated mineral Ca2+ and phosphorous deposited on the surface of osteoblast cells. The mineralization was significantly increased in PCL/HA‐modified nanofibrous scaffolds and appeared as a mineral nodule synthesized by osteoblasts similar to apatite of the natural bone. The present study indicated that the PCL/HA surface‐modified nanofibrous scaffolds are potential for the mineralization of osteoblast for bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
The formation of tertiary dentin after pulp capping with a calcium phosphate cement, loaded with PLGA microparticles containing TGF‐β1
Authors: Zhang Weibo , Walboomers X. Frank , Jansen John A.
Published: August 2007

The aim of the current study was to evaluate the effect of a calcium phosphate material equipped with poly (lactic‐co‐glycolic acid) microspheres for pulp capping, and to measure the dentin bridge formation, when using various concentrations of transforming growth factor (TGF) β1. Preset samples were made (2 mm diameter; 2 mm height), containing 0 (controls), 20, or 400 ng TGF‐β1. These were placed in goat incisors. Incisors capped with glass‐ionomer cement only were used as negative controls. Twelve weeks after pulp capping, the incisors were retrieved, processed for histology, and graded on basis of tertiary dentin formation. The results showed that new dentin formation was seen in all samples, except the negative controls. The histological grading indicated significant differences between the samples loaded with high amount of TGF‐β1 versus the three other groups (p < 0.05). In conclusion, our study demonstrated that the composite with 400 ng TGF‐β1 was able to trigger resident stem cells in the pulp to differentiate into odontoblast‐like cells and to induce the formation of tertiary dentin. The material might be a good candidate for vital pulp therapy. Production and manipulation methods could be improved for follow‐up studies. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Fabricate coaxial stacked nerve conduits through soft lithography and molding processes
Authors: Wang De‐Yao , Huang Yi‐You
Published: August 2007

In this article we present a new way to fabricate nerve conduits with various multi‐channels patterns by microfabrication. Soft lithography was used to manufacture silicon‐based structures and replicate them with PDMS for producing nerve conduit subunit molds. After that, 3% chitosan/acetic acid solution was filled into PDMS molds and then hardened and peeled off. Nerve conduit subunits were fabricated repeatedly by a set of methods for mass production. Afterward, a plurality of conduit subunits stacked coaxially and coated with outer membrane to form the whole nerve conduit. Because of the precise capability of soft lithography, it is well‐suited for nerve conduits with complex designs, such as a combination of multiple degradation control and drug delivery system. Besides, the miniaturization and batch processes are serviceable to the economic effect and the utilization in industry. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008