bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and development of Nostoc strands in Leiosporoceros dussii (Anthocerotophyta): a novel symbiosis in land plants
Authors: Villarreal A. Juan Carlos , Renzaglia Karen Sue
Published: February 2008

The presence of Nostoc in longitudinally oriented schizogenous canals is a feature that separates Leiosporoceros from all other hornworts and represents a novel symbiotic arrangement in land plants. In surface view, Nostoc canals are visible as elongated, dichotomously branched blue‐green strands. All other hornworts develop numerous discrete globose colonies through continuous production of mucilage clefts as avenues for multiple invasions within a single thallus. To elucidate the anatomy and development of the unusual Nostoc strands in Leiosporoceros, we examined sporeling development in culture and the structure of strands in field‐collected plants using light and electron microscopy. Rosette‐like sporelings have mucilage clefts scattered along swollen apices. All field specimens were strap‐shaped, contained Nostoc, and lacked mucilage clefts. Nostoc strands are located in the center of the thallus and develop behind the apical cell by separation of the middle lamella between apical derivatives. Strands elongate and branch in synchrony with apical growth, and thus only a single invasion is required for strand production. Two distinct ultrastructural morphotypes in the collections suggest nonspecificity of Nostoc. We speculate that Nostoc enters the thallus in the sporeling stage through mucilage clefts, and once colonies are established, cleft production ceases.
Cataphylls of the Middle Triassic cycad Antarcticycas schopfii and new insights into cycad evolution
Authors: Hermsen Elizabeth J. , Taylor Thomas N. , Taylor Edith L. , Stevenson Dennis Wm.
Published: February 2008

Cataphylls associated with the Middle Triassic stem genus Antarcticycas are described, and their impact on understanding cycad evolution is discussed. The cataphylls of Antarcticycas are triangular in outline and flattened adaxially with lateral flanges. The outer surfaces are covered with a ramentum of filamentous hairs, the epidermis is a single cell layer thick, and the ground tissue is parenchymatous with mucilage canals and sclereids. Vascular bundles form a distinct inverted omega‐shaped pattern characteristic of the Cycadales observed in petioles of extant species. The structures in Antarcticycas are interpreted as cataphylls based on overall morphology, presence of straight vascular strands in the cortex of the associated stem, and lack of fascicular cambia in the vascular bundles. Because much of the overall diversity of Cycadales is represented by fossils, integrating fossil taxa into explicit phylogenetic hypotheses is important for understanding cycad evolution. Therefore, character and minimum age mapping were performed on a phylogeny of extant and fossil taxa including Antarcticycas. The results suggest that major extant lineages of Cycadales had diverged by the Permian to Triassic and that certain synapomorphies for Cycadales had evolved by the Permian. Evidence of insect feeding on Antarcticycas suggests that associations between cycads and insects are ancient.
An origin of aerial branch parasitism in the mistletoe family, Loranthaceae
Authors: Wilson Carol A. , Calvin Clyde L.
Published: February 2008

The large mistletoe family, Loranthaceae, contains 75 genera and approximately 1000 species. The family originated in the Southern Hemisphere and dispersed, apparently early, between fragments of Gondwana. It is now widely distributed on land surfaces of the former supercontinent. The Loranthaceae has three terrestrial, root‐parasitic genera—a habit considered ancestral—and 72 genera of aerial, branch parasites. For almost two centuries, the origin of the mistletoe habit has been of interest to biologists. Two main evolutionary pathways have been proposed to explain the transition from terrestrial to aerial parasitism in the family. One theorizes the presence of an intermediate climbing ancestor in the path to the aerial habit. The other proposes a direct transfer from terrestrial to epiphytic growth following the germination of seeds on tree branches. Here we present molecular and morphological evidence that (1) the terrestrial speciesNuytsia floribundais ancestral within the Loranthaceae, (2) aerial parasitism has had multiple origins in the family, (3) the first aerial branch parasites had epicortical roots, and (4) the origin of aerial parasitism in one Old World clade involved the direct transfer from terrestrial to epiphytic growth following the germination of seeds on tree branches. Our results suggest that it is not necessary to evoke a climbing intermediate in the origins of aerial parasitism in the Santalales.
Ancestral reconstruction of flower morphology and pollination systems in Schizanthus (Solanaceae)
Authors: Pérez Fernanda , Arroyo Mary T. K. , Medel Rodrigo , Hershkovitz Mark A.
Published: February 2008

Concerted changes in flower morphology and pollinators provide strong evidence on adaptive evolution. Schizanthus (Solanaceae) has zygomorphic flowers and consists of 12 species of annual or biennial herbs that are distributed mainly in Chile and characterized by bee‐, hummingbird‐, and moth‐pollination syndromes. To infer whether flowers diversified in relation to pollinator shifts, we traced the evolutionary trajectory of flower traits and visitors onto a phylogeny based on sequence data from ITS, waxy, and trnF/ndhJ DNA. Maximum‐likelihood ancestral reconstruction of floral traits suggests that ancestral Schizanthus had a bee‐pollination syndrome. The hummingbird syndrome evolved in S. grahamii, a high elevation species in the Andes. The moth syndrome evolved in the ancestor of three species that inhabit the Atacama Desert. Results of mapping flower visitors onto the phylogeny show that the shift from bee to hummingbird pollination concurred with a shift in pollinators as predicted by the syndromes. However, the same pattern was not found for the moth syndrome. Visits by moths were observed only in one of the three moth‐syndrome species, and at a very low rate. This mismatch suggests either anachronic floral characters or maintenance of rare, imperceptible moth pollination backed up by capacity for autonomous selfing. Overall, results suggest that diversification of flower traits in Schizanthus has occurred in relation to pollinator shifts.
Homoplasious character combinations and generic delimitation: a case study from the Indo‐Pacific arecoid palms (Arecaceae: Areceae)
Authors: Norup Maria Vibe , Dransfield John , Chase Mark W. , Barfod Anders S. , Fernando Edwino S. , Baker William J.
Published: February 2008

The complex distributions of morphological character states in the Indo‐Pacific palm tribe Areceae (Arecaceae; Arecoideae) are potentially challenging for the delimitation of its genera. In the first exhaustive sampling of all 65 genera of the Areceae, we examined relationships of two of the tribe's most problematic genera, Heterospathe and Rhopaloblaste, using portions of the low‐copy nuclear genes phosphoribulokinase (PRK) and RNA‐polymerase II subunit B (RPB2). Both genera fell within a highly supported clade comprising all Areceae genera, but are clearly unrelated. Rhopaloblaste was strongly supported as monophyletic and is most closely related to Indian Ocean genera. Heterospathe was resolved with strong support within a clade of western Pacific genera, but with the monotypic Alsmithia nested within it. Ptychosperma micranthum, which has previously been included in both Heterospathe and Rhopaloblaste, is excluded from these and from Ptychosperma, supporting its recent placement in a new genus Dransfieldia. Morphological comparisons indicate that the crownshaft is putatively synapomorphic for the Areceae with numerous reversals within the clade and some independent origins elsewhere. The putative diagnostic characters of Heterospathe show high levels of homoplasy, and the genus can only be distinguished by a suite of characters, whereas Rhopaloblaste is more clearly defined. Our results have implications not only for the two genera in focus, but have also been influential for the new classification of the Areceae.
Origins and nature of vessels in monocotyledons: 8. Orchidaceae
Authors: Carlquist Sherwin , Schneider Edward L.
Published: February 2008

Xylem of the orchids studied provided unusually favorable material to demonstrate how conductive tissue evolves in monocotyledons. In the end walls of tracheary elements of many Orchidaceae, remnants of pit membranes were observed with scanning electron microscopy and minimally destructive methods. The full range from tracheids to vessel elements, featuring many intermediate stages, was illustrated with SEM in hand sections of fixed roots, stems, and inflorescence axes of 13 species from four subfamilies. Pit membranes in end walls of tracheary elements are porose to reticulate in roots of all species, but nonporose in stems of Cypripedioideae and Vanilloideae and porose to reticulate in stems of Orchidoideae and Epidendroideae. The distribution pattern of pit membranes and pit membrane remnants in end walls of tracheary elements of orchids parallels the findings of others. The position of Cypripedioideae and Vanilloideae as outgroups to Orchidoideae and Epidendroideae, claimed by earlier authors, is supported by clades based on molecular studies and by our studies. Little hydrolysis of pit membranes in tracheary element end walls was observed in pseudobulbs or inflorescence axes of epidendroids. The pervasiveness of network‐like pit membranes of various extents and patterns in end walls of tracheary elements in Orchidaceae calls into question the traditional definitions of tracheids and vessel elements, not merely in orchids, but in angiosperms at large. These two concepts, based on light microscope studies, are blurred in light of ultrastructural studies. More importantly, the intermediate expressions of pit membranes in tracheary element end walls of Orchidaceae and some other families of angiosperms are important as indicators of steps in evolution of conduction with respect to organs (more rapid flow in roots than in succulent storage structures) and habitat (less obstruction to flow correlated with a shift from terrestrial to epiphytic).
Differential responses of invasive Celastrus orbiculatus (Celastraceae) and native C. scandens to changes in light quality
Authors: Leicht Stacey A. , Silander John A.
Published: February 2008

When plants are subjected to leaf canopy shade in forest understories or from neighboring plants, they not only experience reduced light quantity, but light quality in lowered red : far red light (R : FR). Growth and other developmental responses of plants in reduced R : FR can vary and are not consistent across species. We compared how an invasive liana, Celastrus orbiculatus, and its closely related native congener, C. scandens, responded to changes in the R : FR under controlled, simulated understory conditions. We measured a suite of morphological and growth attributes under control, neutral shading, and low R : FR light treatments. Celastrus orbiculatus showed an increase in height, aboveground biomass, and total leaf mass in reduced R : FR treatments as compared to the neutral shade, while C. scandens had increased stem diameter, single leaf area, and leaf mass to stem mass ratio. These differences provide a mechanistic understanding of the ability of C. orbiculatus to increase height and actively forage for light resources in forest understories, while C. scandens appears unable to forage for light and instead depends upon a light gap forming. The plastic growth response of C. orbiculatus in shaded conditions points to its success in forested habitats where C. scandens is largely absent.
Ecological genetics and seed transfer guidelines for Pinus albicaulis (Pinaceae)
Authors: Bower Andrew D. , Aitken Sally N.
Published: February 2008

Whitebark pine (Pinus albicaulis Engelm.) has greatly declined throughout its range as a result of introduced disease, fire suppression, and other factors, and climate change is predicted to accelerate this decline. Restoration is needed; however, no information regarding the degree of local adaptation is available to guide these efforts. A seedling common‐garden experiment was employed to assess genetic diversity and geographic differentiation (QST) of whitebark pine for traits involved in growth and adaptation to cold and to determine climatic variables revealing local adaptation. Seedlings from 48 populations were grown for two years and measured for height increment, biomass, root to shoot ratio, date of needle flush, fall and spring cold injury, and survival. Significant variation was observed among populations for most traits. The QST was low (0.07–0.14) for growth traits and moderate (0.36–0.47) for cold adaptation related traits, but varied by region. Cold adaptation traits were strongly correlated with mean temperature of the coldest month of population origins, while growth traits were generally correlated with growing season length. We recommend that seed transfer for restoration favor seed movement from milder to colder climates to a maximum of 1.9°C in mean annual temperature in the northern portion of the species range, and 1.0°C in the U. S. Rocky Mountains to avoid maladaptation to current conditions yet facilitate adaptation to future climates.
Moses Judah Folkman 1933–2008
Authors: Gold P.
Published: February 2008

On January 14, a bright light in the field of cancer research was extinguished with the sudden death of Dr. Judah Folkman. Folkman first introduced the concept [...]
“Crack Lung and Heart” Presenting after Chemotherapy in a 65-Year-Old Man with Non-Hodgkin Lymphoma
Authors: Alvarez G. G. , van der Jagt R. H. C.
Published: February 2008

Crack cocaine can cause a variety of pulmonary and cardiac complications. Pulmonary findings in a 65- year-old man with non-Hodgkin lymphoma who presented with shortness of breath not resolving with antibiotics are presented here. The usual manifestation of “crack lung” in an unusual clinical circumstance underlines the importance of a clinical history in such cases. The finding of “crack lung” preceded the diagnosis of probable “crack heart.” No other similar published case reports could be identified in the literature.
Differences in electrical stimulation thresholds between men and women
Authors: Maffiuletti Nicola A. , Herrero Azael J. , Jubeau Marc , Impellizzeri Franco M. , Bizzini Mario
Published: February 2008

Objective

Surface electrical stimulation (ES) of skeletal muscle is used in a variety of clinical settings in healthy and unhealthy subjects of both sexes. Although women generally present larger amounts of subcutaneous adipose tissue than men, which could limit current flow to the stimulated muscle, sex‐related differences in ES current levels have not been clearly demonstrated to date. We report data from healthy men and wom

Methods

Sensory (current perception), motor (minimal knee extension torque production), and supramotor thresholds (10% of the maximal voluntary knee extension torque) and perceived pain during surface ES of the quadriceps femoris muscle were investigated in 40 healthy volunteers (20 men, 20 women).

Results

Sensory threshold was lower in women than in men (−43%; p < 0.001). Similarly, female muscles required lower current amplitudes to attain the supramotor threshold (−17%; p < 0.01). The Visual Analogue Scale pain score was significantly greater in women than in men at motor threshold (+112%; p < 0.01) but not at supramotor threshold (+36%; p > 0.05).

Interpretation

Collectively, our data demonstrate higher sensory and supramotor excitability to surface ES in female subjects and provide further evidence for a neurophysiological explanation for more pronounced pain perception in women. These observations may help clinicians to better understand the sex‐specific response to ES and to design more rational stimulation treatments with the ultimate goal of optimizing patient care and safety. Ann Neurol 2008
Characterization of hot‐pressed films from superfine wool powder
Authors: Wang Xin , Xu Weilin , Wang Xungai
Published: February 2008

In this study, superfine wool powder was plasticized with glycerol and hot‐pressed into a film. Scanning electron microscopy photos showed that the superfine wool powder could be molded into a smooth film and that the wool powder was distributed evenly in the cross section of the film. Fourier transform infrared analysis revealed no substantial changes in the chemical structure of the wool powder after hot pressing, but the absorbing peaks of glycerol were found in the spectrum. X‐ray diffraction analysis showed that the overall crystallinity increased after the wool powder was hot‐pressed into film. Thermogravimetry (TG) analysis indicated that the thermal stability of the hot‐pressed film decreased. A transition point appeared in the TG curve of the wool hot‐pressed film as glycerol was added. The differential thermal analysis curve of the film showed sharp absorbing peaks similar to that of wool powder. With increasing glycerol content, the film showed increasing ductility and softness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Cobalt Hydroxide Nanosheets and Their Thermal Decomposition to Cobalt Oxide Nanorings
Authors: Liu Xiaohe , Yi Ran , Zhang Ning , Shi Rongrong , Li Xingguo , Qiu Guanzhou
Published: February 2008

We demonstrate herein that single‐crystalline β‐cobalt hydroxide (β‐Co(OH)2) nanosheets can be successfully synthesized in large quantities by a facile hydrothermal synthetic method with aqueous cobalt nitrate as the cobalt source and triethylamine as both an alkaline and a complexing reagent. This synthetic method has good prospects for the future large‐scale production of single‐crystalline β‐Co(OH)2 nanosheets owing to its high yield, low cost, and simple reaction apparatus. Single‐crystalline porous nanosheets and nanorings of cobalt oxide (Co3O4) were obtained by a thermal‐decomposition method with single‐crystalline β‐Co(OH)2 nanosheets as the precursor. A probable mechanism of formation of β‐Co(OH)2 nanosheets, porous Co3O4 nanosheets, and Co3O4 nanorings was proposed on the basis of the experimental results.
Small‐Molecule Inhibitors of Sodium Iodide Symporter Function
Authors: Lecat‐Guillet Nathalie , Merer Goulven , Lopez Roman , Pourcher Thierry , Rousseau Bernard , Ambroise Yves
Published: February 2008

The Na+/I− symporter (NIS) mediates iodide uptake into thyroid follicular cells. Although NIS has been cloned and thoroughly studied at the molecular level, the biochemical processes involved in post‐translational regulation of NIS are still unknown. The purpose of this study was to identify and characterize inhibitors of NIS function. These small organic molecules represent a starting point in the identification of pharmacological tools for the characterization of NIS trafficking and activation mechanisms. The screening of a collection of 17 020 druglike compounds revealed new chemical inhibitors with potencies down to 40 nM. Fluorescence measurement of membrane potential indicates that these inhibitors do not act by disrupting the sodium gradient. They allow immediate and total iodide discharge from preloaded cells in accord with a specific modification of NIS activity, probably through distinct mechanisms.
Hydrophobic Modification and Regeneration of Shirasu Porous Glass Membranes on Membrane Emulsification Performance
Authors: Cheng C.‐J. , Chu L.‐Y. , Xie R. , Wang X.‐W.
Published: February 2008

The effect of hydrophobic modification and regeneration of Shirasu porous glass (SPG) membranes was systematically investigated on the monodispersity of emulsions. The results showed that the hydrophobic modification and regeneration of SPG membranes had little influence on the monodispersity of emulsions, no matter how many modification and regeneration runs were operated. The emulsification runs affected the emulsification performance to a certain extent when hydrophobically‐modified SPG membranes were used for preparing water‐in‐oil (W/O) emulsions repeatedly. However, they almost did not affect the emulsification performance when regenerated hydrophilic SPG membranes were used for preparing oil‐in‐water (O/W) emulsions. The SPG membranes could be used repeatedly after hydrophobic modification or regeneration with almost the same emulsification performance as fresh or freshly‐modified ones. The results provided some valuable guidance for the repetitive use of SPG membranes to prepare monodisperse O/W and W/O emulsions.
Automated Microscale His‐tagged Protein Purification Using Ni‐NTA Magnetic Agarose Beads
Authors: Meng J. , Walter J.‐G. , Kökpinar Ö. , Stahl F. , Scheper T.
Published: February 2008

To achieve standardized and parallelized microscale protein purification, an automated purification system was developed and optimized using a pipetting robot for purifying large sets of proteins with Ni‐NTA magnetic agarose beads. Recombinant hexahistidine‐tagged proteins β‐glucanase (Bgl‐His) and esterase I of Pseudomonas fluorescens (PFE I) were tested on the system. High purity along with high coherence was achieved. The purification procedure can be applied to 96 samples simultaneously and only takes about 1/3 of the time required for purification conducted by hand. Due to the stability of the robot system, the consistency of the results is much better than the results achieved through manual purification. This rapid and reliable method is reproducible and applicable to high throughput screening of huge amounts of samples.
Investigating Amine Derivatives of Ambruticin VS‐5 and VS‐4
Authors: Tian Zong‐Qiang , Wang Zhan , Xu Yuan , Tran Chau Q. , Myles David C. , Zhong Ziyang , Simmons Jessica , Vetcher Leandro , Katz Leonard , Li Yong , Shaw Simon J.
Published: February 2008

A structure–activity relationship around the amine group of the ambruticin VS series has been developed for antifungal activity. It was shown that the amine can be alkylated through reductive amination without loss of potency. However, if it is converted into either an amide, carbamate, or urea, a significant loss of potency is observed. Of the alkyl amines, small nonpolar groups are optimal for both potency and oral bioavailability. As a result of this study, one compound (KOS‐2079) was taken into an animal efficacy model with success.
Combined pegylated liposomal doxorubicin and bortezomib is highly effective in patients with recurrent or refractory multiple myeloma who received prior thalidomide/lenalidomide therapy
Authors: Sonneveld Pieter , Hajek Roman , Nagler Arnon , Spencer Andrew , Bladé Joan , Robak Tadeusz , Zhuang Sen H. , Harousseau Jean‐Luc , Orlowski Robert Z. ,   for the DOXIL‐MMY‐3001 Study Investigators
Published: February 2008

BACKGROUND

Recently, the authors reported improved time to disease progression (TTP) with a combination of pegylated liposomal doxorubicin (PLD) and bortezomib compared with bortezomib alone in a phase 3 randomized trial in patients with recurrent/refractory multiple myeloma (MM). In the current analysis, they determined 1) the efficacy of PLD plus bortezomib versus bortezomib alone in patients with MM who had failed on prior thalidomide/lenalidomide (immunomodulatory drug [IMiD]) treatment and 2) the efficacy and safety profile of PLD plus bortezomib in IMiD‐exposed and IMiD‐naive patients.

METHODS

This prespecified analysis included 646 patients who were randomized to receive either PLD with bortezomib (n = 324; 194 IMiD‐naive patients and 130 IMiD‐exposed patients) or bortezomib alone (n = 322; 184 IMiD‐naive patients and 138 IMiD‐exposed patients). The primary efficacy endpoint was TTP, and secondary endpoints included overall survival, response rate, and safety.

RESULTS

The median TTP was significantly longer with PLD plus bortezomib compared with bortezomib alone in IMiD‐exposed patients (270 days vs 205 days). No statistical difference was noted with respect to TTP between IMiD‐naive (295 days) versus IMiD‐exposed (270 days) subgroups who received PLD plus bortezomib. A sustained trend favoring combination therapy was observed in analyses of overall survival. In patients who achieved a response, the response duration was comparable for IMiD‐naive patients and IMiD‐exposed patients in the combination treatment group and lasted a median of 310 days and 319 days, respectively. The incidence of grade 3/4 adverse events was similar with PLD plus bortezomib regardless of prior IMiD exposure.

CONCLUSIONS

A significantly prolonged TTP was observed with combined PLD plus bortezomib combination therapy compared with bortezomib alone despite prior IMiD exposure. For the combination treatment arm in the IMiD‐naive and IMiD‐exposed subgroups, TTP was comparable. Similarly, the safety profile of the PLD plus bortezomib combination was unaltered by prior IMiD exposure. Cancer 2008. © 2008 American Cancer Society.
Pulmonary resection in patients with nonsmall‐cell lung cancer treated with gamma‐knife radiosurgery for synchronous brain metastases
Authors: Yang Seung‐Yeob , Kim Dong Gyu , Lee Se‐Hoon , Chung Hyun‐Tai , Paek Sun Ha , Hyun Kim Joo , Jung Hee‐Won , Han Dae Hee
Published: February 2008

BACKGROUND

The aim of the current study was to determine whether a pulmonary resection and gamma‐knife radiosurgery (GKRS) protocol is superior to GKRS alone in selected patients with stage IV nonsmall‐cell lung cancer (NSCLC).

METHODS

The authors performed a retrospective case‐control study of 232 consecutive patients with newly diagnosed NSCLC from January 1998 to December 2005 and screened them to identify a study cohort in which all patients had thoracic stage I or II, Karnofsky performance status ≥70, no extracranial metastases, and 1–3 synchronous brain metastases of less than 3 cm, and were treated with GKRS (n = 31). The study cohort was divided into 2 groups, those with and without concomitant pulmonary resection.

RESULTS

Sixteen patients with pulmonary resection were assigned to the treatment group and 15 without pulmonary resection were assigned to the control group. Median follow‐up was 27.3 months (range, 4.4 months to 90.9 months). Mean survivals for the treatment group and the control group were 64.9 and 18.1 months, respectively (P < .001). There was a statistically significant association between pulmonary resection and better survival (OR = 78.408). One‐year and 5‐year local brain tumor control rates were 97.1% and 93.5%, respectively.

CONCLUSIONS

The pulmonary resection and GKRS protocol could prolong survival in patients with thoracic stage I or II NSCLC, no extracranial metastases, and a limited number of small synchronous brain metastases. Cancer 2008. © 2008 American Cancer Society.
Neutral and Monocationic Half‐Sandwich Methyl Rare‐Earth Metal Complexes: Synthesis, Structure, and 1,3‐Butadiene Polymerization Catalysis
Authors: Robert Dominique , Spaniol Thomas P. , Okuda Jun
Published: February 2008

Half‐sandwich rare‐earth metal tetramethylaluminate complexes [Ln(η5‐C5Me4SiMe3){(μ‐Me)2(AlMe2)}2] (Ln = Y, La, Nd, Sm, Gd, Lu) were obtained by reaction of the neutral homoleptic tetramethylaluminate complex [Ln{(μ‐Me)2(AlMe2)}3] with tetramethyl(trimethylsilyl)cyclopentadiene, (C5Me4H)SiMe3. Protonolysis reaction of the neutral mono(cyclopentadienyl) complexes with the Brønsted acid [NEt3H]+[BPh4]– in thf led to the formation of the monocationic methyl complexes [Ln(η5‐C5Me4SiMe3)Me(thf)3]+[BPh4]– (Ln = Y, La, Nd, Sm, Lu). Single‐crystal X‐ray diffraction study on the Y, Sm, and Lu derivatives showed a four‐legged piano‐stool configuration. Upon activation with [Ph3C]+[B(C6F5)4]–, the neutral half‐sandwich tetramethylaluminate complex [La(η5‐C5Me4SiMe3){(μ‐Me)2(AlMe2)}2] catalyzed the polymerization of butadiene in the presence of [AliBu3] to give trans‐1,4‐polybutadiene with narrow polydispersities (Mn/Mw = 1.05–1.09).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Implementation of high‐order compact finite‐difference method to parabolized Navier–Stokes schemes
Authors: Esfahanian Vahid , Hejranfar Kazem , Mahmoodi Darian Hossein
Published: February 2008

The numerical solution to the parabolized Navier–Stokes (PNS) and globally iterated PNS (IPNS) equations for accurate computation of hypersonic axisymmetric flowfields is obtained by using the fourth‐order compact finite‐difference method. The PNS and IPNS equations in the general curvilinear coordinates are solved by using the implicit finite‐difference algorithm of Beam and Warming type with a high‐order compact accuracy. A shock‐fitting procedure is utilized in both compact PNS and IPNS schemes to obtain accurate solutions in the vicinity of the shock. The main advantage of the present formulation is that the basic flow variables and their first and second derivatives are simultaneously computed with the fourth‐order accuracy. The computations are carried out for a benchmark case: hypersonic axisymmetric flow over a blunt cone at Mach 8. A sensitivity study is performed for the basic flowfield, including profiles and their derivatives obtained from the fourth‐order compact PNS and IPNS solutions, and the effects of grid size and numerical dissipation term used are discussed. The present results for the flowfield variables and also their derivatives are compared with those of other basic flow models to demonstrate the accuracy and efficiency of the proposed method. The present work represents the first known application of a high‐order compact finite‐difference method to the PNS schemes, which are computationally more efficient than Navier–Stokes solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Planning for transformation
Authors: Moen Diane M.
Published: February 2008

The University of Wisconsin‐Stout, recipient of the Baldrige National Quality Award in 2001, developed a planning system that has evolved into a comprehensive and collaborative process for visioning, developing and implementing goals, and tracking university performance.
Strategic HRM practices and their impact on company performance in Chinese enterprises
Authors: Akhtar Syed , Ding Daniel Z. , Ge Gloria L.
Published: February 2008

This study examined the factorial validity of strategic human resource management practices and their effects on company performance in a sample of 465 Chinese enterprises. Data were collected through two questionnaire surveys among general managers and HRM directors on product/service performance of their companies and a range of strategic HRM practices. Our findings indicate that a valid set of strategic HRM practices (training, participation, results‐oriented appraisals, and internal career opportunities) affect both product/service performance and financial performance. Employment security and job descriptions contribute uniquely to product/service performance, whereas profit sharing contributes uniquely to financial performance. © 2008 Wiley Periodicals, Inc.
Institutional antecedents and performance consequences of employment security and career advancement practices: Evidence from the people's republic of China
Authors: Gong Yaping , Chang Song
Published: February 2008

In this study, we examine the provision of employment security and career advancement opportunities in firms of diverse institutional ownership and the impact of such practices on employee and firm outcomes. The sample included 478 state‐owned and non‐state‐owned firms (i.e., domestic private firms, Sino‐foreign joint ventures, and wholly‐foreign‐owned firms) in the People's Republic of China. We found that the provision of employment security was greater in state‐owned than in non‐state‐owned firms. The provision of career advancement opportunities in domestic private firms and Sino‐foreign joint ventures was similar to that in wholly foreign‐owned firms, but greater than that in state‐owned firms. The provision of career advancement opportunities was positively related to employee organizational commitment, citizenship behaviors, and firm performance. The provision of employment security was positively related to employee organizational commitment, but not to citizenship behaviors or firm performance. © 2008 Wiley Periodicals, Inc.
How do I trust thee? The employee‐organization relationship, supervisory support, and middle manager trust in the organization
Authors: Zhang Ann Yan , Tsui Anne S. , Song Lynda Jiwen , Li Chaoping , Jia Liangding
Published: February 2008

Given the assumption that most employers would like to gain the trust of their employees, what would initiate this trust? This study explores the joint role of the employee‐organization relationship (EOR) and supervisory support in initiating trust among middle managers. The results from a study of 545 middle managers in China show that both EOR and supervisory support are important in creating trust, with supervisory support having a stronger influence than EOR. Further, supervisors play a synergistic role by accentuating the positive influence of the mutual investment EOR approach and attenuating the negative influence of the quasi‐spot contract EOR with the managers. Results reinforce the importance of both formal structure and social processes in cultivating employee trust in the organization. We discuss implications of these findings for future research and human resource management practices. © 2008 Wiley Periodicals, Inc.
Spatial heterogeneity of water temperature across an alpine river basin
Authors: Brown Lee E. , Hannah David M.
Published: February 2008

River temperature remains a subject of major worldwide research, yet understanding of multi‐scale thermal variability across river systems is limited. Such studies are necessary to elucidate the relative importance of site‐specific (reach‐scale) versus landscape controls. This article addresses this research need by identifying water temperature variability across an alpine river basin, using high‐resolution (15 min) water column temperature data at 29 sites in the Taillon–Gabiétous basin, French Pyrénées. Thermal patterns were examined in relation to a suite of meteorological (incoming shortwave radiation, air temperature, and precipitation) and basin characteristics (altitude, azimuth, stream length, and stream order). Mean water temperature for the monitoring period varied markedly across the river basin, ranging from 0·4 °C at the Taillon Glacier to 14·6 °C in a south‐facing hillslope groundwater stream. Basin‐scale water temperature patterns were strongly influenced by stream water source. Stream temperature was also significantly associated with basin characteristics, most notably altitude, azimuth, and stream length. Thermal heterogeneity across the basin was higher than that along the Taillon Glacier stream, despite rapid longitudinal warming rates with distance from the glacier snout. The timing of thermal extremes (maximum/minimum) during two contrasting hydrometeorological events (hot summer day vs intense hail/rain storm) revealed a clear synchronicity of thermal response among sites, although notable exceptions included karstic groundwater streams that were weakly influenced by concurrent meteorological conditions. Overall, the study demonstrates high thermal heterogeneity at the basin scale (being equal to, or greater than, that found in previous investigations), and the major effect of water source and landscape factors such as altitude, azimuth, and stream length on alpine stream temperature. Copyright © 2008 John Wiley & Sons, Ltd.
The influence of riparian woodland on stream temperatures: implications for the performance of juvenile salmonids
Authors: Malcolm I. A. , Soulsby C. , Hannah D. M. , Bacon P. J. , Youngson A. F. , Tetzlaff D.
Published: February 2008

Stream temperature was monitored at five mainstem locations and one tributary location on the Girnock Burn, a 31‐km2 tributary catchment of the Aberdeenshire Dee in north‐east Scotland. Stream temperature was recorded at 15‐min resolution between April 2003 and March 2006 to investigate the influence of semi‐natural riparian woodland on the spatial and temporal variability of stream temperature and the influence that this had on the performance of juvenile Atlantic salmon (Salmo salar). Two upstream sites were located in open moorland locations, while three downstream sites were located in areas of mixed deciduous/coniferous woodland areas at progressive distances of 0·75, 1·5 and 2·0 km from the upstream edge of continuous riparian tree cover. The effects of riparian woodland on stream temperature varied through the year, increasing during the spring to a maximum in summer, before decreasing once again in autumn. Maximum, mean and diel temperature amplitude were lower and minimum temperatures higher at woodland sites when compared to those located in open moorland. Although significant differences in fish performance were detected between sites, the influence of temperature variability was unclear due to confounding factors, some of which could not be measured during the study. It is recommended that future studies should combine advances in field‐based temperature monitoring with those in hydroclimatology to develop realistic process‐based models that can be used for stream temperature prediction. Further advances are needed in understanding the relationship between naturally variable thermal regime and fish performance in order that ecological predictions can be usefully made from field and modelled temperature data. © Crown Copyright 2008. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Vγ9Vδ2 T cell cytotoxicity against tumor cells is enhanced by monoclonal antibody drugs—Rituximab and trastuzumab
Authors: Tokuyama Hirotake , Hagi Tomomi , Mattarollo Stephen R. , Morley Jacqueline , Wang Qiao , Fai‐So Hang , Moriyasu Fuminori , Nieda Mie , Nicol Andrew J.
Published: February 2008

Vγ9Vδ2 T cells exert potent cytotoxicity toward various tumor cells and adoptive transfer of Vγ9Vδ2 T cells is an attractive proposition for cell based immunotherapy. Vγ9Vδ2 T cells expanded in the presence of Zoledronate and IL‐2 express CD16 (FcγRIII), which raises the possibility that Vγ9Vδ2 T cells could be used in conjunction with tumor targeting monoclonal antibody drugs to increase antitumor cytotoxicity by antibody dependent cellular cytotoxicity (ADCC). Cytotoxic activity against CD20‐positive B lineage lymphoma or chronic lymphocytic leukemia (CLL) and HER2‐positive breast cancer cells was assessed in the presence of rituximab and trastuzumab, respectively. Cytotoxicity of Vγ9Vδ2 T cells against CD20‐positive targets was higher when used in combination with rituximab. Similarly, Vγ9Vδ2 T cells used in combination with trastuzumab resulted in greater cytotoxicity against HER2‐positive cells in comparison with either agent alone and this effect was restricted to the CD16+Vγ9Vδ2 T cell population. Our results show that CD16+Vγ9Vδ2 T cells recognize monoclonal antibody coated tumor cells via CD16 and exert ADCC similar to that observed with NK cells, even when target cells are relatively resistant to monoclonal antibodies or Vγ9Vδ2 T cells alone. Combination therapy involving ex vivo expanded CD16+Vγ9Vδ2 T cells and monoclonal antibodies may enhance the clinical outcomes for patients treated with monoclonal antibody therapy. © 2008 Wiley‐Liss, Inc.
Reactive nitrogen species‐dependent DNA damage in EBV‐associated nasopharyngeal carcinoma: The relation to STAT3 activation and EGFR expression
Authors: Ma Ning , Kawanishi Michiko , Hiraku Yusuke , Murata Mariko , Huang Guang‐Wu , Huang Yuanjiao , Luo Dian‐Zhong , Mo Wei‐Guang , Fukui Yoshihiro , Kawanishi Shosuke
Published: February 2008

Nasopharyngeal carcinoma (NPC) is strongly associated with Epstein‐Barr virus (EBV) infection. Recently, reactive nitrogen and oxygen species are considered to participate in inflammation‐related carcinogenesis through DNA damage. In our study, we obtained biopsy and surgical specimens of nasopharyngeal tissues from NPC patients in southern China, and performed double immunofluorescent staining to examine the formation of 8‐nitroguanine, a nitrative DNA lesion and 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine, an oxidative DNA lesion, in these specimens. Strong DNA lesions were observed in cancer cells and inflammatory cells in stroma of NPC patients. Intensive immunoreactivity of iNOS was detected in the cytoplasm of 8‐nitroguanine‐positive cancer cells. DNA lesions and iNOS expression were also observed in epithelial cells of EBV‐positive patients with chronic nasopharyngitis, although their intensities were significantly weaker than those in NPC patients. In EBV‐negative subjects, no or little DNA lesions and iNOS expression were observed. EGFR and phosphorylated STAT3 were strongly expressed in cancer cells of NPC patients, but NF‐κB was not expressed, suggesting that STAT3‐dependent mechanism is important for NPC carcinogenesis. IL‐6 was expressed mainly in inflammatory cells of nasopharyngeal tissues of EBV‐infected patients. EBV‐encoded RNAs (EBERs) and latent membrane protein 1 (LMP1) were detected in cancer cells from all EBV‐infected patients. In vitro cell system, nuclear accumulation of EGFR was observed in LMP1‐expressing cells, and IL‐6 induced phosphorylated STAT3 and iNOS. These data suggest that nuclear accumulation of EGFR and STAT3 activation byIL‐6 play the key role in iNOS expression and resultant DNA damage, leading to EBV‐mediated NPC. © 2008 Wiley‐Liss, Inc.
Is gravity linear?
Authors: Henderson Daniel J. , Millimet Daniel L.
Published: February 2008

Despite the solid theoretical foundation on which the gravity model of bilateral trade is based, empirical implementation requires several assumptions which do not follow directly from the underlying theory. First, unobserved trade costs are assumed to be a (log‐)linear function of observables. Second, the effects of trade costs on trade flows are assumed to be constant across country pairs. Maintaining consistency with the underlying theory, but relaxing these assumptions, we estimate gravity models—in levels and logs—using two data sets via nonparametric methods. The results are striking. Despite the added flexibility of the nonparametric models, parametric models based on these assumptions offer equally or more reliable in‐sample predictions and out‐of‐sample forecasts in the majority of cases, particularly in the levels model. Moreover, formal statistical tests fail to reject either parametric functional form. Thus, concerns in the gravity literature over functional form appear unwarranted, and estimation of the gravity model in levels is recommended. Copyright © 2008 John Wiley & Sons, Ltd.
The generalized Born/volume integral implicit solvent model: Estimation of the free energy of hydration using London dispersion instead of atomic surface area
Authors: Labute Paul
Published: February 2008

A new generalized Born model for estimating the free energy of hydration is presented. The new generalized Born/volume integral (GB/VI) estimates the free energy of hydration as a classical electrostatic energy plus a cavitation energy that is not based upon atomic surface area (SA) used in GB/SA hydration models but on a VI London dispersion energy estimated from quantities already calculated in the classical electrostatic energy. The (relatively few) GB/VI model parameters are fitted to experimental data, and parameterizations for two different atomic partial charge models are presented. Comparison of the calculated and experimental free energies of hydration for 560 small molecules (both neutral and charged) shows good agreement (r2 = 0.94). © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Molecular simulation of multistate peptide dynamics: A comparison between microsecond timescale sampling and multiple shorter trajectories
Authors: Monticelli Luca , Sorin Eric J. , Tieleman D. Peter , Pande Vijay S. , Colombo Giorgio
Published: February 2008

Molecular dynamics simulations of the RN24 peptide, which includes a diverse set of structurally heterogeneous states, are carried out in explicit solvent. Two approaches are employed and compared directly under identical simulation conditions. Specifically, we examine sampling by two individual long trajectories (microsecond timescale) and many shorter (MS) uncoupled trajectories. Statistical analysis of the structural properties indicates a qualitative agreement between these approaches. Microsecond timescale sampling gives large uncertainties on most structural metrics, while the shorter timescale of MS simulations results in slight structural memory for beta‐structure starting states. Additionally, MS sampling detects numerous transitions on a relatively short timescale that are not observed in microsecond sampling, while long simulations allow for detection of a few transitions on significantly longer timescales. A correlation between the complex free energy landscape and the kinetics of the equilibrium is highlighted by principal component analysis on both simulation sets. This report highlights the increased precision of the MS approach when studying the kinetics of complex conformational change, while revealing the complementary insight and qualitative agreement offered by far fewer individual simulations on significantly longer timescales. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Multicomponent ion exchange isotherms in NaX zeolite: evaluation of Cr/Ca/Mg, Cr/Ca/K and Cr/Mg/K systems
Authors: Barros Maria Angélica S.D. , Arroyo Pedro A. , Sousa‐Aguiar Eduardo F. , Tavares Célia R.G.
Published: February 2008

BACKGROUND: One of the most important heavy metals is Cr3+, which is commonly found together with Ca2+, Mg2+ and K+ ions in tannery wastewaters. Such metals can be removed through ion exchange process using zeolite NaX. Unfortunately, with single exchange mechanisms it is impossible to predict muti‐component and competitive interactions. This work is aimed at overcoming this problem. Ion exchange isotherms of Cr3+, Mg2+, Ca2+ and K+ in ternary mixtures (Cr/Mg/Ca, Cr/Ca/K, Cr/Mg/K) using NaX zeolite at 30 °C, 45 °C and 60 °C are studied and reported.

RESULTS: Ion exchange is dependent on temperature, and on the nature and interaction of ingoing cations. Sequential ion exchange occurs where one cation is able to displace another already located in the site. Values of the equilibrium constant of all cations investigated are close to each other, which indicates a weak preference for Cr+3. The affinity order is as follows: for Cr/Ca/Mg–NaX isotherms, Cr3+ > Ca2+ > Mg2+ at 30 °C, Ca2+ > Cr3+ > Mg2+ at 45 °C and Ca2+ > Mg2+ > Cr3+ at 60 °C. For Cr/Ca/K–NaX isotherms the sequence is Cr3+ > Ca2+ > K+ for the three temperatures and for Cr/Mg/K–NaX isotherms, Cr3+ > Mg2+ > K+ at 30 and 45 °C and Mg2+ > K+ > Cr3+ at 60 °C.

CONCLUSION: It can be concluded that ions with a high charge such as Cr3+ are not always preferentially removed from multi‐component solution. Therefore, exchanges in NaX zeolite are useful when there is no need to have high chromium removal when compared to the competitive cations investigated here. Copyright © 2008 Society of Chemical Industry