bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of the Active Fracture Concept in Modeling Unsaturated Flow and Transport in a Fractured Meter‐Sized Block of Rock
Authors: Seol Yongkoo , Kneafsey Timothy J. , Ito Kazumasa
Published: December 2005

Numerical simulation is an effective and economical method for optimally designing laboratory experiments and deriving practical experimental conditions. We executed a detailed numerical simulation study to examine the active fracture concept (AFC) using a 1‐m3‐sized block model. The numerical simulations for this study were performed by applying various experimental conditions, including different bottom flow boundaries, varying injection rates, and different fracture–matrix interaction (i.e., by increasing absolute matrix permeability at the fracture–matrix boundary) for a larger fracture interaction under transient or balanced‐state flow regimes. Two conceptual block models were developed based on different numerical approaches: a two‐dimensional discrete‐fracture‐network model (DFNM) and a one‐dimensional dual‐continuum model (DCM). The DFNM was used as a surrogate for a natural block to produce synthetic breakthrough curves of water and tracer concentration under transient or balanced‐state conditions. The DCM is the approach typically used for the Yucca Mountain Project because of its computational efficiency. The AFC was incorporated into the DCM to capture heterogeneous flow patterns that occur in unsaturated fractured rocks. The simulation results from the DCM were compared with the results from the DFNM to determine whether the DCM could predict the water flow and tracer transport observed in the DFNM at the scale of the experiment. It was found that implementing the AFC in the DCM improved the prediction of unsaturated flow and that the flow and transport experiments with low injection rates in the DFNM compared better with the AFC implemented DCM at the 1‐m3 scale. However, the estimated AFC parameter varied from 0.38 to 1.0 with different flow conditions, suggesting that the AFC parameter was not sufficient to fully capture the complexity of the flow processes in a 1‐m3 discrete fracture network.
Modeling Two‐Dimensional Water Flow and Bromide Transport in a Heterogeneous Lignitic Mine Soil
Authors: Buczko Uwe , Gerke Horst H.
Published: December 2005

Water and solute fluxes in lignitic mine soils and in many other soils are often highly heterogeneous. Here, heterogeneity reflects dumping‐induced inclined structures and embedded heterogeneous distributions of sediment mixtures and of lignitic fragments. Such two‐scale heterogeneity effects may be analyzed through the application of two‐dimensional models for calculating water and solute fluxes. The objective of this study was to gain more insight to what extent spatial heterogeneity of soil hydraulic parameters contributes to preferential flow at a lignitic mine soil. The simulations pertained to the “Bärenbrücker Höhe” site in Germany where previously water fluxes and applied tracers had been monitored with a cell lysimeter, and from where a soil block had been excavated for detailed two‐dimensional characterization of the hydraulic parameters using pedotransfer functions. Based on those previous studies, scenarios with different distributions of hydraulic parameters were simulated. The results show that spatial variability of hydraulic parameters alone can hardly explain the observed flow patterns. The measured bromide distributions both in the leachate and the residual concentrations in the soil could not be described at all. Consequently, the observed preferential flow at the site was probably caused by additional factors such as hydrophobicity, the presence of root channels, anisotropy in the hydraulic conductivity, and heterogeneous root distributions. To study the relative importance of these other factors by applying two‐dimensional flow models to such sites, the experimental database must be improved, especially with regard to the effects of hydrophobicity and the impacts of high‐root‐density zones. Single‐continuum model approaches may be insufficient for such sites.
A Modified Mualem–van Genuchten Formulation for Improved Description of the Hydraulic Conductivity Near Saturation
Authors: Schaap Marcel G. , van Genuchten Martinus Th.
Published: December 2005

The unsaturated soil hydraulic properties are often described using Mualem–van Genuchten (MVG) type analytical functions. Recent studies suggest several shortcomings of these functions near saturation, notably the lack of second‐order continuity of the soil water retention function at saturation and the inability of the hydraulic conductivity function to account for macroporosity. We present a modified MVG formulation that improves the description of the hydraulic conductivity near saturation. The modified model introduces a small but constant air‐entry pressure (hs) into the water retention curve. Analysis of the UNSODA soil hydraulic database revealed an optimal value of −4 cm for hs, more or less independent of soil texture. The modified model uses a pressure dependent piece‐wise linear correction to ensure that deviations between measured and fitted conductivities between pressure heads of 0 and −40 cm were eliminated. A small correction was found necessary between −4 and −40 cm, and a much larger correction was needed between 0 and −4 cm. An average RMSE in logK of only 0.26 remained for a data set of 235 samples. The resulting modified MVG model was found to have small systematic errors across the entire pressure range. The modified model appears well suited for large‐scale vadose zone flow and transport simulations, including inverse modeling studies.
Saturated and Unsaturated Hydraulic Conductivities and Water Retention Characteristics of Weathered Granitic Bedrock
Authors: Katsura Shin'ya , Kosugi Ken'ichirou , Yamamoto Nobuhiro , Mizuyama Takahisa
Published: December 2005

As a first step toward describing water flow processes in bedrock, we determined the hydraulic properties of three trimmed samples of weathered granitic bedrock (referred to as Samples A, B, and C, in order of size) in the laboratory. Silicone rubber was used to fill the space between each sample and the surrounding cylinder wall, ensuring accurate measurement of hydraulic properties of the samples. All samples showed similar saturated hydraulic conductivity values of 1 × 10−4 cm s−1, with the saturated water flow in all samples obeying Darcy's Law. Unsaturated hydraulic conductivity and water retention functions of Sample A were determined by means of a multistep outflow experiment. Parameters in both functions were optimized by comparing observed and computed cumulative outflow rates. The resulting computed cumulative outflow rates using the optimized parameters showed a good match to the observed cumulative outflow data. Moreover, the derived water retention function agreed closely with the function measured by the pressure plate method. We conclude that the methods proposed in this study are effective for determining the hydraulic properties of weathered bedrock. The bedrock water retention curve exhibited small changes in volumetric water content throughout the measurement range where the pressure head, ψ, was greater than −200 cm. The bedrock hydraulic conductivity function showed a small decrease in hydraulic conductivity in the very wet range of ψ greater than −30 cm, and then declined gradually with decreasing ψ.
Applicability of Uni‐ and Bimodal Retention Functions for Water Flow Modeling in a Tropical Acrisol
Authors: Spohrer Klaus , Herrmann Ludger , Ingwersen Joachim , Stahr Karl
Published: December 2005

Modeling soil water fluxes is an important part of many agricultural and environmental investigations and applications. A prerequisite for accurate modeling results is a sound parameterization of the soil hydraulic functions. The aim of this study was to investigate whether the unimodal retention function is sufficient to simulate the soil water regime of an Acrisol in Northern Thailand. The van Genuchten parameterization and its modification by Vogel and Cislerova were compared with the bimodal van Genuchten parameterization of Durner. Parameters of the soil hydraulic functions were optimized by solving the inverse problem of a one‐dimensional transient flow field experiment. Simulations using the bimodal approach resulted in the best agreement between measured and simulated data. Results with the modified van Genuchten function had a lower degree of accuracy but were still sufficient to predict the soil water balance. In case of the original van Genuchten approach, unrealistically high saturated hydraulic conductivities were required to obtain satisfactory simulation results. Hence, in fine‐textured soils those optimized Ks values should be considered as fitting and not as physical parameters.
Suction Lysimeter Modifications to Improve Sampling Efficiency and Prevent Wildlife Damage
Authors: Crabtree Charles G. , Seaman Tina M.
Published: December 2005

During the course of research using suction lysimeters, it became apparent that simple modifications to the lysimeters could save both time and money. The procedure for extracting samples was inefficient and there was potential for cross‐contamination of samples. In addition, wildlife was damaging the lysimeters, causing project delays and costly repairs. Relatively simple and inexpensive modifications to the lysimeters were made to remedy both of these problems without having to purchase new lysimeters. The suction lysimeters were retrofitted with permanent sample extraction tubes and quick‐connects to increase the efficiency of sample extraction and to reduce the likelihood of cross‐contamination of samples. A protective PVC casing was installed around the lysimeters to prevent wildlife tampering. These casings also served to prevent lysimeter damage from a grass fire at the study site. These modifications increased sampling efficiency by 50% and eliminated damage to lysimeters caused by wildlife and fire.
Comparison of Different Monitoring Programs of the 2002 Summer Flood in the River Elbe
Authors: Baborowski Martina , Claus Evelyn , Friese Kurt , von der Kammer Frank , Kasimir Petra , Pelzer Jürgen , Heininger Peter
Published: December 2005

The water quality of the river Elbe near Magdeburg represents the pollution situation of the middle course of the river Elbe under normal discharge conditions. In order to identify critical changes in the water quality caused by the century flood in August 2002, numerous measurement programs were launched accompanying the flood wave. This paper compares and discusses results based on different sampling strategies and analytical methods of three institutions mainly using the example of trace metals.
Assessing the Pollution of Water Protection Areas and River Banks along the Elbe and Mulde Rivers after the Flood Event in August 2002
Authors: Strauch Gerhard , Bittkau Anke , Schlosser Dietmar , Petzoldt Heike , Sbjeschnid André
Published: December 2005

Investigations addressing the pollution with inorganic and potentially pathogenic contaminants resulting from the August 2002 high flood event of the rivers Elbe and Mulde have been performed in water protection areas and along the inundated banks of both rivers. Soil and plant material were investigated for potential pathogens and indicator organisms such as coliforms, Escherichia coli, enterococci, Clostridium perfringens, Pseudomonas aeruginosa, and for inorganic compounds like Al, Zn, nitrate, and orthophosphate. Soil sediments down to a depth of 120 cm, as well as soils and plants along traverses have extensively been studied over a time range of up to one year after the flood event but in none of these environmental compartments a significant maintenance of pollutants could be proven. However, recommendations are given concerning the assessment of microbiological contamination that may arise from possible future flood events.
Ecotoxicological Profiling of Transect River Elbe Sediments
Authors: Grote Matthias , Altenburger Rolf , Brack Werner , Moschütz Susanne , Mothes Sibylle , Michael Claudia , Narten Gesa‐Britt , Paschke Albrecht , Schirmer Kristin , Walter Helge , Wennrich Rainer , Wenzel Klaus‐Dieter , Schüürmann Gerrit
Published: December 2005

During the river Elbe flood in August 2002, large amounts of suspended organic matter were transported and settled in the course of the river. The aim of this study was to assess the quality of river Elbe sediments using chemical and biological methods. For this purpose 11 samples from river Elbe and 2 from tributaries were investigated. Two contact biotest systems, used to identify the ecotoxic potential of sediments, showed toxic effects in all sediments. Exposure was assessed by quantification of priority pollutants; however, no causal link to biological effects could be established. Effect qualities were characterised by testing organic sediment extracts in a biotest battery consisting of 8 test systems. Test systems varied in sensitivity to detect effects in the samples. Furthermore, samples differed in their ecotoxic potential. An effect‐directed analysis was conducted in order to identify compounds responsible for the biological effects. Cause‐effect relationships were established for mixtures of polycyclic aromatic hydrocarbons being partially responsible for toxic effects on algal reproduction; however the majority of the cause for toxicity remained unclear. Overall, it has to be concluded that Elbe sediments are not in accord with current quality goals. The chemical and the biological transect profile of the sediments indicate toxicant inputs from Czech Republic, river Mulde and diverse source.
Multitemporal and Multispectral Remote Sensing Approach for Flood Detection in the Elbe‐Mulde Region 2002
Authors: Gläßer Cornelia , Reinartz Peter
Published: December 2005

The extreme flood event of the Elbe and Mulde Rivers in August 2002 caused, with its very sharp rise and decline of the water masses, a manifold of damage to the infrastructure as well as toxic deposits in the flooded areas. The paper gives a summary of the processing of multitemporal and multisensor remote sensing data for the purpose of monitoring this event. Methods and results for several thematic questions are presented and discussed. Procedures for the detection of flooded areas with operational satellite data (Landsat‐7 ETM, IRS) are investigated. Further studies are performed regarding the classification of moisture classes in the flood plain in relation to the high water changes, the accumulation of sediments and silts for different land use classes and the erosive impact of the flood by using data with high spatial resolution from satellite (IKONOS) and from aircraft (Daedalus‐Scanner).

The time series of multispectral scanner data are very well suited for the spatial analysis of the damage and ecological risk, caused by the flood. The results correlate well with the data from in‐situ measurements. At the same time they show how the gathering of samples can be optimized by using remote sensing data. The results can be directly integrated in existing GIS of the public authorities for the assessment and management of extreme flood events.
Polybenzimidazole nanofiltration hollow fiber for cephalexin separation
Authors: Wang Kai Yu , Chung Tai‐Shung
Published: December 2005

Most conventional nanofiltration (NF) hollow‐fiber membranes are fabricated by means of multiple steps of posttreatments. Because of the unique amphoteric characteristics of the imidazole group in polybenzimidazole (PBI), a novel PBI NF hollow‐fiber membrane with appropriate charge characteristics has been fabricated by a one‐step phase‐inversion process without posttreatment. The resultant mechanically stable PBI membranes can withstand pressures up to 30 bars. It is found that the mean effective pore size decreases, whereas the pure water permeability increases with an increase in elongational draw ratio. The novel PBI NF hollow‐fiber membrane exhibits higher rejection to divalent cations, lower rejection to divalent anions, and the lowest rejection to monovalent ions at pH 7.0. Thus the divalent and monovalent ions of both NaCl/MgCl2 and NaCl/Na2SO4 binary salt solutions can be effectively fractionated by the PBI NF membrane arising from ion competition. The surface charge characteristics of the PBI NF membrane are strongly dependent on pH. Therefore, by adjusting the pH of cephalexin aqueous solution to modify the ionization states of these dipolar cephalexin molecules, PBI NF membranes show high separation effectiveness for the recovery of this antibiotic from solution over a wide range of pH values. © 2005 American Institute of Chemical Engineers AIChE J, 2006
On the trail of pulmonary tuberculosis based on rib lesions: Results from the human identified skeletal collection from the Museu Bocage (Lisbon, Portugal)
Authors: Matos Vítor , Santos Ana Luísa
Published: December 2005

In the last 20 years, studies on human identified skeletal collections have revealed a significant relationship between new bone formation on the visceral surface of ribs and pulmonary tuberculosis (TB). To improve methods of differential diagnosis of respiratory diseases in archaeological skeletons, an investigation was conducted on 197 individuals from the Human Identified Skeletal Collection of the Museu Bocage (Lisbon, Portugal). This sample included 109 males and 88 females who lived during the 19th–20th centuries, with ages at death ranging from 13–88 years. The skeletons were grouped according to cause of death: 1) pulmonary TB (N = 84); 2) pulmonary non‐TB diseases (N = 49); and 3) a control group (N = 64) composed of individuals randomly selected among the extrapulmonary non‐TB causes of death. The ribs, sterna, scapulae, and clavicles were macroscopically observed. New bone formation on the visceral surface of ribs was recorded in 90.5% (76/84) of individuals who died from pulmonary TB, in 36.7% (18/49) with a pulmonary non‐TB disease as cause of death, and in 25.0% (16/64) of the control group. These differences were statistically significant (P < 0.001). Furthermore, in individuals with pulmonary TB, the bony lesions presented mainly as lamellar bone on the vertebral end of the upper and middle thoracic rib cage. Proliferative alterations also occurred on one sternum and in nine clavicles and eight scapulae. This work strongly supports the results of similar studies performed on other documented collections, suggesting that new bone formation on ribs, although not pathognomonic, is a useful criterion for the differential diagnosis of pulmonary TB. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Cortical bone remodeling rates in a sample of African American and European American descent groups from the American Midwest: Comparisons of age and sex in ribs
Authors: Cho Helen , Stout Sam D. , Bishop Thomas A.
Published: December 2005

This study employs regression analysis to explore population and sex differences in the pattern of age‐associated bone loss, as reflected by histomorphometric variables that are measures of intracortical and endocortical bone remodeling. A comparison of an African American sample from the Washington Park Cemetery in St. Louis, Missouri, and a European American rib sample composed of cadavers, autopsies, and forensic cases from Missouri reveals the existence of complex age‐associated patterns for differences in measures of intracortical remodeling and cortical area. Females from the two samples express similar bone dimensions and dynamics. The African American females appear to lose more bone than their male counterparts, but this difference is absent in the European American sample. When age‐associated patterns are considered, it is in the younger cohorts that African Americans exhibit greater relative cortical area than European Americans, but this is reversed in the older ages, when the latter group manifests greater bone mass. The European American males consistently differ in the slopes and intercepts for the variables compared to the other groups, and differences are highly significant with African American females, with the former group maintaining bone mass while the latter exhibit a more rapid bone loss. Achieving larger relative cortical area due to smaller endosteal area, coupled with better bone quality due to lower intracortical porosity early in life, may be a mechanism by which African Americans, especially females, maintain adequate bone mass in older ages, which buffers them from bone loss and related fragility fractures despite higher rates of intracortical remodeling and endosteal expansion later in life. These results suggest that both genetic and environmental factors are responsible for the differences in bone remodeling and bone mass observed between these samples. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Skin and hair pigmentation variation in Island Melanesia
Authors: Norton Heather L. , Friedlaender Jonathan S. , Merriwether D. Andrew , Koki George , Mgone Charles S. , Shriver Mark D.
Published: December 2005

Skin and hair pigmentation are two of the most easily visible examples of human phenotypic variation. Selection‐based explanations for pigmentation variation in humans have focused on the relationship between melanin and ultraviolet radiation, which is largely dependent on latitude. In this study, skin and hair pigmentation were measured as the melanin (M) index, using narrow‐band reflectance spectroscopy for 1,135 individuals from Island Melanesia. Overall, the results show remarkable pigmentation variation, given the small geographic region surveyed. This variation is discussed in terms of differences between males and females, among islands, and among neighborhoods within those islands. The relationship of pigmentation to age, latitude, and longitude is also examined. We found that male skin pigmentation was significantly darker than females in 5 of 6 islands examined. Hair pigmentation showed a negative, but weak, correlation with age, while skin pigmentation showed a positive, but also weak, correlation with age. Skin and hair pigmentation varied significantly between islands as well as between neighborhoods within those islands. Bougainvilleans showed significantly darker skin than individuals from any other island considered, and are darker than a previously described African‐American population. These findings are discussed in relation to prevailing hypotheses about the role of natural selection in shaping pigmentation variation in the human species, as well as the role of demographic processes such as admixture and drift in Island Melanesia. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Neonatal porencephaly and adult stroke related to mutations in collagen IV A1
Authors: van der Knaap Marjo S. , Smit Leo M. E. , Barkhof Frederik , Pijnenburg Yolande A. L. , Zweegman Sonja , Niessen Hans W. M. , Imhof Saskia , Heutink Peter
Published: December 2005

Objective

The objective of this study was to describe leukoencephalopathy, lacunar infarcts, microbleeds and macrobleeds in the context of a collagen IV A1 mutation.

Methods

We examined a family with autosomal dominant porencephaly, in whom a defect in collagen IV A1 was detected recently. The patients underwent neurological, ophthalmological, and cardiological examinations and magnetic resonance imaging of the brain. Electron microscopy of a skin biopsy was performed. Extensive laboratory screening was performed for thrombophilia and increased bleeding tendency.

Results

The porencephaly was symptomatic in the infantile period in two patients, whereas it led to only minor neurological dysfunction in their affected mother. However, she experienced development of recurrent strokes in her 40s. In addition to the porencephaly, all patients had a leukoencephalopathy, which was most severe in the mother. Her magnetic resonance imaging results also showed lacunar infarcts, macrobleeds and a multitude of microbleeds. No other risk factors for recurrent stroke were found. Electron microscopy showed interruptions of the basement membrane of skin capillaries and inhomogeneous thickening of the basement membrane with pools of basement membrane fragments.

Interpretation

Leukoencephalopathy, ischemic infarcts, microbleeds, and macrobleeds are indicative of an underlying microangiopathy, of which the best‐known causes are hypertension, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and cerebral amyloid angiopathy. Mutations in collagen IV A1, a major component of the vascular basement membrane, appear to be another risk factor. Ann Neurol 2005
Subcomplexes of human ATP synthase mark mitochondrial biosynthesis disorders
Authors: Carrozzo Rosalba , Wittig Ilka , Santorelli Filippo M. , Bertini Enrico , Hofmann Sabine , Brandt Ulrich , Schägger Hermann
Published: December 2005

Objective

Methods: We describe biochemically and clinically relevant aspects of mitochondrial ATP synthase, the enzyme that supplies most ATP for the cells energy demand.

Results

Analyzing human Rho zero cells we could identify three subcomplexes of ATP synthase: F1 catalytic domain, F1 domain with bound natural IF1 inhibitor protein, and F1‐c subcomplex, an assembly of F1 domain and a ring of FO‐subunits c. Large amounts of F1 subcomplexes accumulated also in mitochondria of patients with specific mitochondrial disorders. By quantifying the F1 subcomplexes and other oxidative phosphorylation complexes in parallel, we were able to discriminate three classes of defects in mitochondrial biosynthesis, namely, mitochondrial DNA depletion, mitochondrial transfer RNA (tRNA) mutations, and mutations in the mitochondrial ATP6 gene.

Interpretation

The relatively simple electrophoretic assay used here is a straightforward approach to differentiate between various types of genetic alterations affecting the biosynthesis of oxidative phosphorylation complexes and will be useful to guide molecular genetic diagnostics in the field of mitochondrial neuromuscular disorders. Ann Neurol 2006
Investigating oligonucleotide hybridization at subnanomolar level by surface plasmon resonance biosensor method
Authors: Vaisocherová Hana , Zítová Alice , Lachmanová Markéta , S̆tĕpánek Josef , Králíková S̆árka , Liboska Radek , Rejman Dominik , Rosenberg Ivan , Homola Jir̆í
Published: December 2005

We have optimized surface plasmon resonance (SPR) biosensor technology for a rapid, direct, and low‐consumption label‐free multianalyte screening of synthetic oligonucleotides (ONs) with modified internucleotide linkages potentially applicable in antisense therapy. Monitoring of the ONs hybridization is based on the formation of complex between the natural oligonucleotide probe immobilized on the sensor surface and the ON in solution in contact with the sensor surface. An immobilization chemistry utilizing the streptavidin–biotin interaction was employed to obtain desired ligand density and high hybridization efficiency. It was demonstrated that the sensor is capable of detecting complementary 23‐mer ONs in concentrations as low as 0.1 nM with high specificity and reproducibility. © 2005 Wiley Periodicals, Inc. Biopolymers 82:394–398, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Randomized clinical trial comparing laparoscopic and open surgery for colorectal cancer within an enhanced recovery programme
Authors: King P M , Blazeby J M , Ewings P , Franks P J , Longman R J , Kendrick A H , Kipling R M , Kennedy R H
Published: December 2005

Background

Laparoscopic resection of colorectal cancer may improve short-term outcome without compromising long-term survival or disease control. Recent evidence suggests that the difference between laparoscopic and open surgery may be less significant when perioperative care is optimized within an enhanced recovery programme. This study compared short-term outcomes of laparoscopic and open resection of colorectal cancer within such a programme.

Methods

Between January 2002 and March 2004, 62 patients were randomized on a 2 : 1 basis to receive laparoscopic (n = 43) or open (n = 19) surgery. All were entered into an enhanced recovery programme. Length of hospital stay was the primary endpoint. Secondary outcomes of functional recovery, quality of life and cost were assessed for 3 months after surgery.

Results

Demographics of the two groups were similar. Length of hospital stay after laparoscopic resection was 32 (95 per cent confidence interval (c.i.) 7 to 51) per cent shorter than for open resection (P = 0·018). Combined hospital, convalescent and readmission stay was 37 (95 per cent c.i. 10 to 56) per cent shorter (P = 0·012). The relative risk of complications, quality of life results and cost data were similar in the two groups.

Conclusion

Despite perioperative optimization of open surgery for colorectal cancer, short-term outcomes were better following laparoscopic surgery. There was no deterioration in quality of life or increased cost associated with the laparoscopic approach.
Asymmetric Hydrogenation of Imines and Olefins Using Phosphine‐Oxazoline Iridium Complexes as Catalysts
Authors: Trifonova Anna , Diesen Jarle S. , Andersson Pher G.
Published: December 2005

Herein we describe the synthesis of a new class of chiral phosphine‐oxazolines and their application as ligands in iridium‐catalyzed hydrogenations. Mechanistic aspects of olefin hydrogenation with this class of iridium catalysts are discussed and a selectivity model to help rationalize the results obtained is also presented.
Regulation of levels of actin threonine phosphorylation during life cycle of Physarum polycephalum
Authors: Shirai Yuki , Sasaki Narie , Kishi Yoshiro , Izumi Akiko , Itoh Kie , Sameshima Masazumi , Kobayashi Tetsuyuki , Murakami‐Murofushi Kimiko
Published: December 2005

Under various environmental stresses, the true slime mold Physarum polycephalum converts into dormant forms, such as microcysts, sclerotia, and spores, which can survive in adverse environments for a considerable period of time. In drought‐induced sclerotia, actin is threonine phosphorylated, which blocks its ability to polymerize into filaments. It is known that fragmin and actin‐fragmin kinase (AFK) mediate this phosphorylation event. In this work, we demonstrate that high levels of actin threonine phosphorylation are also found in other dormant cells, including microcysts and spores. As the threonine phosphorylation of actin in microcysts and sclerotia were induced by drought stress but not by other stresses, we suggest that drought stress is essential for actin phosphorylation in both cell types. Although characteristic filamentous actin structures (dot‐ or rod‐like structures) were observed in microcysts, sclerotia, and spores, actin phosphorylation was not required for the formation of these structures. Prior to the formation of both microcysts and sclerotia, AFK mRNA expression was activated transiently, whereas fragmin mRNA levels decreased. Our results suggest that drought stress and AFK might be involved in the threonine phosphorylation of actin. Cell Motil. Cytoskeleton 2006. © 2005 Wiley‐Liss, Inc.
Trafficking of macromolecules and organelles in cultured Dystonia musculorum sensory neurons is normal
Authors: Pool Madeline , Rippstein Peter , McBride Heidi , Kothary Rashmi
Published: December 2005

Dystonia musculorum (dt) mice suffer from a recessive neuropathy characterized by the progressive loss of sensory axons. The gene responsible for this disorder, dystonin/Bpag1, encodes several alternatively spliced forms of a cytoskeletal linker protein. Neural isoforms of dystonin/Bpag1 are predicted to link actin filaments to microtubules. Consistent with this, previous observations have demonstrated that the cytoskeleton within sensory neurites of dt mice is perturbed. Also, recent results have indicated that a neural isoform of dystonin/Bpag1 interacts with the dynein motor complex. Because microtubule organization and dynein motor function are essential for trafficking, we hypothesized that this process would be perturbed in dt sensory neurons. Here, we demonstrate that cultured primary dorsal root ganglion (DRG) neurons express dystonin/Bpag1 and that loss of this expression causes an increase in apoptosis and a decrease in average neurite length. In contrast, detailed examination showed that the organization of microtubules is indistinguishable in DRG neuronal cultures from neonatal dt and wild‐type mice. In addition, the steady‐state distribution of several molecules and organelles is unchanged in these cultures. Furthermore, the speeds of mitochondrial movement in both anterograde and retrograde directions were comparable in dt and wild‐type sensory neurons cultured from neonatal mice. Thus, dystonin/Bpag1 is not essential for microtubule network assembly since the microtubule network is intact in short‐term cultures of sensory neurons from neonatal mice lacking this protein. In addition, dystonin/Bpag1 is not an essential part of the dynein motor complex for mitochondrial transport since mitochondrial trafficking is normal in cultured sensory neurons from dt mice. J. Comp. Neurol. 494:549–558, 2006. © 2005 Wiley‐Liss, Inc.
Pyramidal cells of the rat basolateral amygdala: Synaptology and innervation by parvalbumin‐immunoreactive interneurons
Authors: Muller Jay F. , Mascagni Franco , McDonald Alexander J.
Published: December 2005

The generation of emotional responses by the basolateral amygdala is determined largely by the balance of excitatory and inhibitory inputs to its principal neurons, the pyramidal cells. The activity of these neurons is tightly controlled by γ‐aminobutyric acid (GABA)‐ergic interneurons, especially a parvalbumin‐positive (PV+) subpopulation that constitutes almost half of all interneurons in the basolateral amygdala. In the present semiquantitative investigation, we studied the incidence of synaptic inputs of PV+axon terminals onto pyramidal neurons in the rat basolateral nucleus (BLa). Pyramidal cells were identified by using calcium/calmodulin‐dependent protein kinase II (CaMK) immunoreactivity as a marker. To appreciate the relative abundance of PV+inputs compared with excitatory inputs and other non‐PV+inhibitory inputs, we also analyzed the proportions of asymmetrical (presumed excitatory) synapses and symmetrical (presumed inhibitory) synapses formed by unlabeled axon terminals targeting pyramidal neurons. The results indicate that the perisomatic region of pyramidal cells is innervated almost entirely by symmetrical synapses, whereas the density of asymmetrical synapses increases as one proceeds from thicker proximal dendritic shafts to thinner distal dendritic shafts. The great majority of synapses with dendritic spines are asymmetrical. PV+axon terminals form mainly symmetrical synapses. These PV+synapses constitute slightly more than half of the symmetrical synapses formed with each postsynaptic compartment of BLa pyramidal cells. These data indicate that the synaptology of basolateral amygdalar pyramidal cells is remarkably similar to that of cortical pyramidal cells and that PV+interneurons provide a robust inhibition of both the perisomatic and the distal dendritic domains of these principal neurons. J. Comp. Neurol. 494:635–650, 2006. © 2005 Wiley‐Liss, Inc.
Developmental period for N‐methyl‐D‐aspartate (NMDA) receptor‐dependent synapse elimination correlated with visuotopic map refinement
Authors: Colonnese Matthew T. , Constantine‐Paton Martha
Published: December 2005

During a short perinatal interval, N‐methyl‐D‐aspartate receptor (NMDAR) function is essential to a process in which spontaneous retinal waves focus retinal axon arbors in the superficial layers of the rodent superior colliculus (sSC). Here we provide evidence that this NMDAR‐dependent axonal refinement occurs through elimination of uncorrelated retinal synapses arising from disparate loci, rather than stabilization of topographically appropriate inputs. The density of synaptic release sites within fluorescently labeled retinal terminals was counted in double‐labeling experiments using confocal microscopy and antibodies against synaptophysin or synapsin‐1. Chronic NMDAR blockade from birth increased retinal axon synapse density at postnatal days (P) 6, 8, and 10, suggesting that NMDAR currents reduce synapse density during the refinement period. With assay at P14, after focal arborization has been established, the effect disappeared. Conversely, chronic NMDA treatment, known to induce functional synaptic depression in the sSC, decreased retinocollicular synapse density at P14, but not earlier, during the refinement period (P8). Thus during the development of retinocollicular topographic order, there is a period when NMDAR activity predominantly eliminates retinal axon synapses. We were able to extend this period by using retinal lesions to reduce synaptic density in a defined zone. Synapse density on intact retinocollicular axons sprouting into this zone was increased by NMDAR blockade, even when examined at P14. Thus, the period of NMDAR‐dependent synaptic destabilization is terminated by a factor related to the density and refinement of retinal arbors. J. Comp. Neurol. 494:738–751, 2006. © 2005 Wiley‐Liss, Inc.
Calretinin immunoreactivity in the brain of the zebrafish, Danio rerio: Distribution and comparison with some neuropeptides and neurotransmitter‐synthesizing enzymes. II. Midbrain, hindbrain, and rostral spinal cord
Authors: Castro Antonio , Becerra Manuela , Manso María Jesús , Anadón Ramón
Published: December 2005

The distribution of calretinin (CR) in the brainstem and rostral spinal cord of the adult zebrafish was studied by using immunocytochemical techniques. For analysis of some brainstem nuclei and regions, CR distribution was compared with that of complementary markers (choline acetyltransferase, glutamic acid decarboxylase, tyrosine hydroxylase, neuropeptide Y). The results reveal that CR is a marker of various neuronal populations distributed throughout the brainstem, including numerous cells in the optic tectum, torus semicircularis, secondary gustatory nucleus, reticular formation, somatomotor column, gustatory lobes, octavolateral area, and inferior olive, as well as of characteristic tracts of fibers and neuropil. These results indicate that CR may prove useful for characterizing a number of neuronal subpopulations in zebrafish. Comparison of the distribution of CR observed in the brainstem of zebrafish with that reported in an advanced teleost (the gray mullet) revealed a number of similarities, and also some interesting differences. Our results indicate that many brainstem neuronal populations have maintained the CR phenotype in widely divergent teleost lines, so CR studies may prove very useful for comparative analysis. J. Comp. Neurol. 494:792–814, 2006. © 2005 Wiley‐Liss, Inc.
Afferents to the orexin neurons of the rat brain
Authors: Yoshida Kyoko , McCormack Sarah , España Rodrigo A. , Crocker Amanda , Scammell Thomas E.
Published: December 2005

Emotions, stress, hunger, and circadian rhythms all promote wakefulness and behavioral arousal. Little is known about the pathways mediating these influences, but the orexin‐producing neurons of the hypothalamus may play an essential role. These cells heavily innervate many wake‐promoting brain regions, and mice lacking the orexin neurons have narcolepsy and fail to rouse in response to hunger (Yamanaka et al. [2003] Neuron 38:701–713). To identify the afferents to the orexin neurons, we first injected a retrograde tracer into the orexin neuron field of rats. Retrogradely labeled neurons were abundant in the allocortex, claustrum, lateral septum, bed nucleus of the stria terminalis, and in many hypothalamic regions including the preoptic area, dorsomedial nucleus, lateral hypothalamus, and posterior hypothalamus. Retrograde labeling in the brainstem was generally more modest, but labeling was strong in the periaqueductal gray matter, dorsal raphe nucleus, and lateral parabrachial nucleus. Injection of an anterograde tracer confirmed that most of these regions directly innervate the orexin neurons, with some of the heaviest input coming from the lateral septum, preoptic area, and posterior hypothalamus. In addition, hypothalamic regions preferentially innervate orexin neurons in the medial and perifornical parts of the field, but most projections from the brainstem target the lateral part of the field. Inputs from the suprachiasmatic nucleus are mainly relayed via the subparaventricular zone and dorsomedial nucleus. These observations suggest that the orexin neurons may integrate a variety of interoceptive and homeostatic signals to increase behavioral arousal in response to hunger, stress, circadian signals, and autonomic challenges. J. Comp. Neurol. 494:845–861, 2006. © 2005 Wiley‐Liss, Inc.
Classification of solutions for an integral equation
Authors: Chen Wenxiong , Li Congming , Ou Biao
Published: December 2005

Let n be a positive integer and let 0 < α < n. Consider the integral equation

We prove that every positive regular solution u(x) is radially symmetric and monotone about some point and therefore assumes the form

with some constant c = c(n, α) and for some t > 0 and x0 ϵ ℝn. This solves an open problem posed by Lieb 12. The technique we use is the method of moving planes in an integral form, which is quite different from those for differential equations. From the point of view of general methodology, this is another interesting part of the paper.

Moreover, we show that the family of well‐known semilinear partial differential equations

is equivalent to our integral equation (0.1), and we thus classify all the solutions of the PDEs. © 2005 Wiley Periodicals, Inc.
Controllable Growth of Straight Nanorods and Nanowires in the Langmuir Films of a Bolaamphiphilic PAR Derivative
Authors: Guo Peizhi , Liu Minghua , Nakahara Hiroo , Ushida Kiminori
Published: December 2005

A novel bolaamphiphilic compound, 1, 10‐bis[3′‐hydroxy‐4′‐(2′′‐pyridylazo)phenoloxy] decane [(PAR)2C10], was synthesized and its spreading film and in situ coordination with metal ions in the Langmuir monolayer at the air/water interface were investigated. It was found that (PAR)2C10 could be spread on the water surface, and the Langmuir film showed a phase transition from a flat conformation to a U‐shaped conformation upon compression. Interfacial coordination between (PAR)2C10 and metal ions could occur in situ in the Langmuir monolayer. Depending on the concentration of the subphase, different coordination modes were observed. A 2:1 (ligand‐PAR‐to‐metal‐ion) complex was formed at a lower concentration of the subphase, while a 1:1 complex was obtained on the subphase with a higher concentration of the salt. Interestingly, very straight nanowires, extending to several micrometers, were observed in the AFM images of the films transferred from the subphase containing CuCl2 in higher concentrations. However, tortuous nanowires were observed under the subphase containing Cu(CH3COO)2. The formation of such kind of wirelike structures was only observed for the combination of the bolaamphiphilic PAR derivative with the Cu(II) ions. Other metal ions or the single‐chain PAR derivative did not show this behavior. A possible growth mechanism of the nanowires was proposed based on the coordination of the bolaamphiphilic (PAR)2C10 with the Cu(II) ions as well as with the counteranions.
The First Metal‐Oxo Cluster Containing Lithium and Bismuth
Authors: Mehring Michael , Mansfeld Dirk , Costisella Burkhard , Schürmann Markus
Published: December 2005

The reaction of [Bi(OtBu)3] with LiOSiMe3 gave the heterobimetallic bismuth‐oxo cluster [Bi3Li5(μ5‐O)2(μ3‐OSiMe3)2(μ3‐OtBu)2(μ2‐OtBu)6] (1) after elimination of Me3SiOSiMe3. The cage compound 1 is the first example of a mixed‐metal alkoxide/siloxide composed of lithium and bismuth. Crystals of 1·2 C7H8 and 1·1.5 THF suitable for X‐ray single crystal structure analysis were obtained by crystallisation from toluene and THF, respectively. Both solvates crystallise in the orthorhombic space group Pmmn with Z = 2. The lattice constants are a = 16.267(3) Å, b = 17.126(3) Å and c = 12.155(2) Å (1·2 C7H8) and a = 16.353(2) Å, b = 17.156(1) Å and c = 12.256(1) Å (1·1.5 THF). In both compounds the solvent molecules occupy channels along the c‐axis. The basic molecular unit is best described as a face‐sharing double cubane [BiLi5(μ4‐O)2(μ3‐OSiMe3)2(μ3‐OtBu)2] which is coordinated by two [Bi(OtBu)3] molecules. The compound is kinetically labile in solution and readily decomposes in 1,1,2,2‐tetrachloroethane with elimination of 1,1,2‐trichloroethylene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis, Characterisation and Biological Activity of Chiral Platinum(II) Complexes
Authors: Jaramillo David , Buck Damian P. , Collins J. Grant , Fenton Ronald R. , Stootman Frank H. , Wheate Nial J. , Aldrich‐Wright Janice R.
Published: December 2005

Four platinum(II) complexes of 1,10‐phenanthroline (phen) and 3,4,7,8‐tetramethyl‐1,10‐phenanthroline (3,4,7,8‐Me4phen), with the chiral ancillary ligands (1R,3S) and (1S,3R)‐1,3‐diamino‐1,2,2‐trimethylcyclopentane (R,S‐tmcp andS,R‐tmcp, respectively) have been synthesised and their biological activity quantified using an in vitro cytotoxicity assay against the L1210 murine leukaemia cell line. [Pt(R,S‐tmcp)(3,4,7,8‐Me4phen)]Cl2and [Pt(S,R‐tmcp)(3,4,7,8‐Me4phen)]Cl2showed an increase in biological activity over their non‐methylated complexes, [Pt(R,S‐tmcp)(phen)]Cl2and [Pt(S,R‐tmcp)(phen)]Cl2. Some chiral discrimination was observed in the in vitro cytotoxicity experiments with the complexes having (S,R) configuration showing higher biological activity in L1210 cells. Titrations of the metal complexes into ct‐DNA and observation of the changes induced in the CD spectra were used to determine the binding constants. The binding of these metal complexes to the hexamer d(GTCGAC)2was studied using two‐dimensional1H NMR spectroscopy. The addition of metal complexes to the hexamer produced upfield shifts of the metal complex of selected resonances, characteristic of intercalation for [Pt(tmcp)(phen)]Cl2, whereas the [Pt(tmcp)(3,4,7,8‐Me4phen)]Cl2complexes only partially intercalate and in a “side‐on” fashion. Through the observation of NOE cross‐peaks, two‐dimensional NMR experiments provided some insight into the site and groove preferences of these complexes when binding to DNA. Here, we report the biological activity of platinum(II) complexes containing an intercalator and a chiral diamine, which influences the degree to which the complexes can interact with DNA. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Gelation Ability of Novel Oxamide‐Based Derivatives Bearing a Stilbene as a Photo‐Responsive Unit
Authors: Miljanić Snežana , Frkanec Leo , Meić Zlatko , Žinić Mladen
Published: December 2005

Oxamide‐based derivatives containing one or two oxamide moieties coupled to the 4‐ or 4,4′‐positions of cis‐ and trans‐stilbene have been synthesised. In order to modulate the solvent gelation tendencies, a series of derivatives with modified terminal functions were prepared from them. The trans‐stilbene dioxamide‐based derivatives were found to be sparingly soluble or insoluble in water and in organic solvents, whereas the trans‐stilbene monooxamide‐based derivatives are soluble in most organic solvents. Incorporation of a C12 alkyl chain in the structure of the latter compounds results in a decreased solubility but in an increased gelation tendency of the substances. The ethyl ester oxamide‐based derivative trans‐3a and the amino acid oxamide‐based derivative trans‐3e act as efficient gelators of various organic solvents. In contrast, cis‐3a shows a poor gelation ability or none at all, owing to its good solubility. Considering the difference in gelation abilities of the compounds trans‐3a and cis‐3a and the photo‐responsive conformational changes of the stilbene part of the molecule, a controlled gelation by light was achieved. FT‐IR and 1H NMR spectroscopic measurements support the view that hydrogen bonding between the oxamide fragments plays an important role in gel formation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)