bluuebunny/crossref_metadata_2025 huggingface dataset:
New Routes to High Resolution and Automated Polymer Morphology Microscopy via Scanning Electron Microscopy
Authors: Bar G. , Tocha E. , Garcia‐Meitin E. , Todd C. , Blackson J.
Published: September 2009

Summary: Polymer morphologies are traditionally studied by transmission electron microscopy (TEM). With the use of appropriate contrast enhancing heavy metal stains, direct images of the morphology as well as of the lamellar structure of semi‐crystalline polymers can be obtained. Despite its clear strengths, this approach faces several challenges and difficulties: the laborious nature of ultra‐thin section preparation, high capital investment, and no obvious routes to high‐throughput. We propose an alternative approach to cover the major morphology imaging needs based on a new generation of high resolution scanning electron microscopes (SEM) that have been developed in recent years, and that does not rely on the need for ultra‐thin section preparation. The proposed approach is capable of not only determining the general phase morphology, but also to image details such as the lamellar structure with sufficient resolution. Our approach is based on the use of backscattered electron imaging at low accelerating voltages. The backscattered electron images show high contrast and information content that is comparable to TEM. The main advantage of our SEM based approach is the ability to examine a polished surface, which requires less demanding sample preparation than producing ultra‐thin sections. This opens the door to automated workflows where automated imaging, substantial productivity increases and high speed characterization options can be successfully realized. The successful approach is demonstrated for various polyolefin and engineering plastics samples.
Estimating Slow Crack Growth Performance of Polyethylene Resins from Primary Structures such as Molecular Weight and Short Chain Branching
Authors: DesLauriers Paul J. , Rohlfing David C.
Published: September 2009

Summary: Molecular weight and short chain branching (SCB) data experimentally obtained by SEC‐FTIR are combined into a single, primary structural parameter (PSP2) and used to rapidly screen the slow crack growth resistance of a variety of polyethylene resins. Our results show that PSP2 values obtained for resins made using different catalysts (both dual and single catalyst systems) and hence, different polymer architectures, correlate well with results obtained from several short‐term tensile tests. The development of PSP2, as well as the qualitative and quantitative predictive ability of this parameter are presented and discussed.
In situ Polymerization of Nanocomposites by TpTiCl2(Et) System: UHMWPE Filled with Carbon Nanotubes
Authors: Sánchez Y. , Albano C. , Karam A. , Perera R. , Casas E.
Published: September 2009

Summary: Nanocomposites of ultra‐high molecular weight polyethylene (UHMWPE) filled with multi‐walled carbon nanotubes (CNT) were obtained by in situ polymerization of ethylene by TpTiCl2Et. This novel catalytic complex activated with polymethylaluminoxane (P‐MAO) (Al:Ti = 200) allowed to incorporate the CNT at different compositions (0,1‐1 w/w %) into the UHMWPE matrix. The filler addition produced an important enhancement of the catalytic activity when it was compared to that of homogeneous ethylene polymerization carried out under the same experimental conditions (30 min; 1bar; 25 °C). This fact was attributed to in situ support of TpTiCl2Et onto the CNT surface, which not only could induce the stabilization of the catalytic system but also allowed the growing of polymeric chains around the CNT structures. The characterization of these nanocomposites was carried out by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Thermal analysis showed that the incorporation of CNT (at the tested concentrations) did not produce changes in the polymer thermal stability, as revealed by the initial degradation temperature values. However, the CNT produced a nucleating effect in the crystallization of UHMWPE as observed by DSC, independently of the filler content. The crystallization temperature of the obtained nanocomposites increased and the crystallinity degree slightly increased as well.
Non‐coaxial elasto‐plasticity model and bifurcation prediction of shear banding in sands
Authors: Huang Maosong , Lu Xilin , Qian Jiangu
Published: September 2009

Numerous constitutive models built on coaxial theory and validated under axi‐symmetric condition often describe the stress–stain relationships and predict the inceptions of shear banding in sands inaccurately under true triaxial condition. By adopting an elaborated Mohr–Coulomb yield function and using non‐coaxial non‐associated flow rule, a 3D non‐coaxial elasto‐plasticity model is proposed and validated by a series of true triaxial tests on loose sands. The bifurcation analysis of true triaxial tests on dense sands predicts the influence of the intermediate principal stress ratio on the onset of shear band accurately. The failure of soils is shown to be related to the formation of shear band under most intermediate principal stress ratio conditions except for those which are close to the axi‐symmetric compression condition. Copyright © 2009 John Wiley & Sons, Ltd.
Sacrocolpopexy using xenogenic acellular collagen in patients at increased risk for graft‐related complications
Authors: Claerhout Filip , De Ridder Dirk , Van Beckevoort Dirk , Coremans Georges , Veldman Joan , Lewi Paul , Deprest Jan
Published: September 2009

Aims

We studied the long‐term anatomical and functional outcome following sacrocolpopexy for apical vaginal prolapse using xenogenic grafts in a population at increased risk for graft‐related complications (GRCs).

Methods

Twenty‐two consecutive patients with symptomatic apical prolapse were scheduled for laparoscopic sacrocolpopexy (LSC) with porcine grafts because they were presumed to be at risk for GRC, because of pre‐existing vaginal ulcerations (n = 4), concomitant vaginal prolapse repair (n = 15), total hysterectomy (n = 1), or intra‐operative abdominal contamination due to accidental laceration of the vagina, bowel perforation (n = 1) or the presence of infection (n = 1). Either small intestinal submucosa (n = 8) or dermal collagen (n = 14) was used. Outcome measures were GRCs, anatomical cure (≤Stage I at any compartment), subjective cure, impact on bowel, bladder, and sexual function measured by a standardized interview.

Results

At study closure 20 (91%) patients were available for functional evaluation and 16 (73%) for anatomical evaluation at a mean follow‐up period of 27.4 months. The GRC rate was 25% (n = 4) prompting reintervention in half, and including two patients with spondylodiscitis. The anatomical cure rate was 31.5%. Failures at the vault, anterior, and posterior compartments occurred in, respectively, 31%, 18.8%, and 50% of patients. The subjective cure rate was 60% and three patients (15%) underwent redo‐LSC.

Conclusion

The strategy of using xenografts in patients at risk for GRC, did not prevent these to occur and was associated with a high anatomical and functional failure rate as well as reoperation rate. Neurourol. Urodynam. 29:563–567, 2010. © 2009 Wiley‐Liss, Inc.
Melting and spread of polymers in fire with the particle finite element method
Authors: Oñate Eugenio , Rossi Riccardo , Idelsohn Sergio R. , Butler Kathryn M.
Published: September 2009

A new computational procedure for analysis of the melting and flame spread of polymers under fire conditions is presented. The method, termed particle finite element method (PFEM), combines concepts from particle‐based techniques with those of the standard finite element method (FEM). The key feature of the PFEM is the use of an updated Lagrangian description to model the motion of nodes (particles) in the thermoplastic material. Nodes are viewed as material points that can freely move and even separate from the main analysis domain representing, for instance, the effect of melting and dripping of polymer particles. A mesh connects the nodes defining the discretized domain where the governing equations are solved as in the standard FEM. An incremental iterative scheme for the solution of the non‐linear transient‐coupled thermal‐flow problem, including loss of mass by gasification, is used. Examples of the possibilities of the PFEM for the modeling and simulation of the melting and flame spread of polymers under different fire conditions are described. Numerical results are compared with experimental data provided by NIST. Published in 2009 by John Wiley & Sons, Ltd.
A possible case of ‘poll‐evil’ in an early Scythian horse skull from Arzhan 1, Tuva Republic, Central Asia
Authors: Bendrey R. , Cassidy J. P. , Bokovenko N. , Lepetz S. , Zaitseva G. I.
Published: September 2009

Occipital bone lesions on an Iron Age horse cranium from the burial mound of Arzhan 1, Tuva, Central Asia, are described and interpreted. Cavitations around the nuchal ligament attachment site on the skull are interpreted as foci of inflammation and necrosis following local infection. It is suggested that the pathology represents a case of ‘poll‐evil’, most likely due to a bacterial infection. The significance of such an interpretation is discussed, including its implications for disease ecology and the possible infection risks to contiguous animal and human communities of the first millennium BC in Central Asia. Copyright © 2009 John Wiley & Sons, Ltd.
Behavioral and emotional problems in children with sickle cell disease and healthy siblings: Multiple informants, multiple measures
Authors: Hijmans Channa T. , Grootenhuis Martha A. , Oosterlaan Jaap , Last Bob F. , Heijboer Harriët , Peters Marjolein , Fijnvandraat Karin
Published: September 2009

Background

Behavioral and emotional problems in children with sickle cell disease (SCD) may be related to disease factors, or to socio‐demographic factors. The aim of this study was to investigate the prevalence of behavioral and emotional problems in children with SCD living in a Western European country, compared to healthy siblings (who were comparable in age, gender, ethnicity, and socio‐economic status—SES), and to a Dutch norm population.

Methods

The Child Behavior Checklist (CBCL), Teacher Report Form (TRF) and Disruptive Behavior Disorders rating scale (DBD) were distributed among caregivers and teachers of 119 children with SCD aged 6–18 years and among caregivers and teachers of 38 healthy siblings.

Results

Questionnaires were returned by caregivers and/or teachers of 106 children with SCD and 37 healthy siblings. According to caregivers and teachers, children with SCD had more severe internalizing problems than healthy siblings and the norm population. According to teachers, subgroups of both children with SCD and healthy siblings had more severe externalizing problems than the norm population. Children with SCD had more difficulties than healthy siblings in terms of school functioning, showed less competent social behavior and tended to have more attention deficits.

Conclusions

Children with SCD are at increased risk of developing internalizing problems as a result of their disease. Subgroups of children with SCD are at increased risk of developing severe externalizing problems, which may either be related to socio‐demographic factors, or to disease factors, such as neurocognitive deficits associated with cerebral infarction. Pediatr Blood Cancer 2009; 53:1277–1283. © 2009 Wiley‐Liss, Inc.
Interactions between antiepileptic and chemotherapeutic drugs in children with brain tumors: Is it time to change treatment?
Authors: Ruggiero Antonio , Rizzo Daniela , Mastrangelo Stefano , Battaglia Domenica , Attinà Giorgio , Riccardi Riccardo
Published: September 2009

Epileptic seizures are a common clinical problem in children with brain tumors. The conventional antiepileptic drugs (AEDs) permit a good seizure control in most of these children. An emerging problem is the possible interactions between AEDs and chemotherapeutic drugs, because many of these drugs are metabolized by the cytochrome P450. The aim of this article is to propose a novel therapeutic approach for new‐onset epilepsy in children with brain tumors. Among the new AEDs not metabolized by the P450 system, levetiracetam seems to be a promising AED owing to its pharmacokinetic features, efficacy, and safety. Pediatr Blood Cancer 2010;54:193–198. © 2009 Wiley‐Liss, Inc.
Development of poly(acrylamide)‐hydroxyapatite composites as bone substitutes: Study of mechanical and blood compatible behavior
Authors: Bajpai A.K. , Bundela H.
Published: September 2009

The Hydroxyapatite (HAp) serves as potential biomaterial in various biomedical applications. This study is a continuing attempt to design the biomimetic bone‐like composite materials. The authors have tried to develop HAp/Polyacrylamide (PAm) composites with different weight ratios through a suspension polymerization method. The prepared composite materials were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, optical microscopy techniques, and compressive strength tests. The composites were also studied for water sorption capacity and the water sorption data were used to evaluate network parameters revealing the internal chemical architecture of the composite. In vitro tests were carried out to study water uptake and dissolution profiles of HAp/PAm composites. Furthermore, in vitro blood compatibility of the composites was also judged using protein adsorption, percentage haemolysis, blood clot formation, and platelet adhesion tests. The results obtained fairly support the objectives of the study to meet physiochemical and biological concerns for a bone‐like material. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Gene expression in chorionic villous samples at 11 weeks of gestation in women who develop preeclampsia later in pregnancy: implications for screening
Authors: Farina Antonio , Morano Danila , Arcelli Diego , De Sanctis Paola , Sekizawa Akihiko , Purwosunu Yuditiya , Zucchini Cinzia , Simonazzi Giuliana , Okai Takashi , Rizzo Nicola
Published: September 2009

Objectives

To determine the gene expression profile in chorionic villous samples (CVS) of women destined to develop preeclampsia.

Method

cDNA microarray technology was employed. Ten singleton fetuses of women who subsequently developed preeclampsia where compared with a pool of 50 controls. The mRNA expression of some of the genes previously found to be up‐ or down‐regulated were validated by RT‐PCR in peripheral blood from 23 pregnant women at term affected with preeclampsia and 23 controls.

Results

Altered expression was found among several genes including those involved in invasion of human trophoblasts (Titin), in inflammatory stress (Lactotransferrin), endothelial aberration (Claudin 6), angiogenesis (Vasohibin 1), blood pressure control (Adducin 1). Also the peripheral blood from preeclampsia patients showed significant differences for all the genes studied.

Conclusion

CVS show an aberrant gene profile prior to preeclampsia onset that may be predictive of the disease. Copyright © 2009 John Wiley & Sons, Ltd.
The effect of state extraversion on four types of affect
Authors: McNiel J. Murray , Lowman Joseph C. , Fleeson William
Published: September 2009

The primary purpose of this study was to determine the effect of state extraversion on different types of affect. Ninety six participants were instructed to be extraverted or introverted in a 10‐minute dyadic discussion. State extraversion had a strong effect on positive affect and smaller (but still strong) effects on pleasant and activated affect, with these latter two effects almost equal in magnitude. This pattern of findings appears to increase confidence that the effect of state extraversion is genuine rather than the result of construct overlap, in that extraversion's effect on positive affect is not dominated by its effect on activated affect. No support for reward sensitivity as a potential explanatory mechanism was found. Copyright © 2009 John Wiley & Sons, Ltd.
The integrated control concept and its relevance to current integrated pest management in California fresh market grapes
Authors: Bentley Walter J
Published: September 2009

The foundation of an integrated pest management program involves valid treatment thresholds, accurate and simple monitoring methods, effective natural controls, selective pesticides and trained individuals who can implement the concept.The Integrated Control Conceptwritten by Stern, Smith, van den Bosch and Hagen elucidated each of these points in an alfalfa ecosystem. Alfalfa hay (Medicago sativaL.) has a low per acre value, requires little hand labor and is primarily marketed in the USA. In contrast, fresh market table grape (Vitis viniferaL.) has a high per acre value, requires frequent hand labor operations, suffers unacceptable cosmetic damage and is marketed throughout both the USA and the world. Each of the components of a working IPM program is present in table grape production. Marketing grapes to foreign countries presents special problems with pests considered invasive and where residue tolerances for some selective insecticides are lacking. However, fresh market grape farmers are still able to deal with these special problems and utilize an IPM program that has resulted in a 42% reduction in broad‐spectrum insecticide use from 1995 to 2007. Copyright © 2009 Society of Chemical Industry
A Three Dimensional Pharmacophore Modeling for KDR and Tie‐2 Receptor Tyrosine Kinase Inhibitors and Virtual Screening for New Multikinase Inhibitors
Authors: Kansal Neha , Silakari Om , Ravikumar Muttineni
Published: September 2009

The fundamental role that receptor tyrosine kinases play in cancer and other proliferative diseases has provided the impetus for an extensive effort to develop multikinase inhibitors. In this study three dimensional Pharmacophore models were developed using recently synthesized KDR and Tie‐2 receptor tyrosine kinase inhibitors by using CATALYST HypoGen program. The high cost difference (68.098 for KDR and 46.971 for Tie‐2), good correlation coefficient (0.948 for KDR and 0.963 for Tie‐2) and low root mean square deviation (0.871 for KDR and 0.668 for Tie‐2) suggest that highly predictive pharmacophore models were successfully obtained. The models were further validated by two methods, first by using test set compounds (305 for KDR and 131 for Tie‐2) which resulted a correlation of 0.606 for KDR and 0.706 for Tie‐2 between HypoGen estimated activities vs. experimental activities and secondly by fischer randomization test. The application of the validated pharmacophore models shows great success in screening in‐house database and predicted 61compounds with multikinase activity.
Leaving Flatland: Efficient real‐time three‐dimensional perception and motion planning
Authors: Bogdan Rusu Radu , Sundaresan Aravind , Morisset Benoit , Hauser Kris , Agrawal Motilal , Latombe Jean‐Claude , Beetz Michael
Published: September 2009

In this article we present the complete details of the architecture and implementation of Leaving Flatland, an exploratory project that attempts to surmount the challenges of closing the loop between autonomous perception and action on challenging terrain. The proposed system includes comprehensive localization, mapping, path planning, and visualization techniques for a mobile robot to operate autonomously in complex three‐dimensional (3D) indoor and outdoor environments. In doing so we integrate robust visual odometry localization techniques with real‐time 3D mapping methods from stereo data to obtain consistent global models annotated with semantic labels. These models are used by a multiregion motion planner that adapts existing two‐dimensional planning techniques to operate in 3D terrain. All the system components are evaluated on a variety of real‐world data sets, and their computational performance is shown to be favorable for high‐speed autonomous navigation. © 2009 Wiley Periodicals, Inc.
An adaptive design for identifying the dose with the best efficacy/tolerability profile with application to a crossover dose‐finding study
Authors: Ivanova Anastasia , Liu Ken , Snyder Ellen , Snavely Duane
Published: September 2009

Proof‐of‐concept in clinical trials has traditionally focused on the identification of a maximum tolerated dose with the assumption that the higher doses provide better efficacy. However, adverse events associated with a maximum tolerated dose may have a negative effect on efficacy. We present an efficient adaptive dose‐finding strategy that concentrates patient assignments at and around the dose which has the best efficacy/tolerability profile based on a utility function. The strategy is applied within the setting of a crossover design. While the strategy may also be applied to parallel studies, a crossover design provides more power for a given sample size for comparisons between the optimal dose versus placebo and/or active control when it is reasonable to assume no carryover effects. Copyright © 2009 John Wiley & Sons, Ltd.
Testing for familial aggregation of functional traits
Authors: Fang Yixin , Wang Yuanjia
Published: September 2009

In a genetic epidemiology study of a trait, prior to collecting genotype data the foremost task is to test for familial aggregation and examine heritability. Recently, functional traits have drawn attentions from investigators. Here, to test for familial aggregation of a functional trait in the family studies, a test constructed based on the leading functional principal component of heritability, which is a summary measure of temporal genetic variation in a functional trait, is proposed. The p‐value of the test can be approximated by a permutation procedure given the family structure. The asymptotic distribution of the test statistic is derived. Simulations are carried out to examine the size and the power of the test. The proposed methods are applied to the total cholesterol data in the Framingham Heart Study. Copyright © 2009 John Wiley & Sons, Ltd.
Estimating drug effects in the presence of placebo response: Causal inference using growth mixture modeling
Authors: Muthén Bengt , Brown Hendricks C.
Published: September 2009

Placebo‐controlled randomized trials for antidepressants and other drugs often show a response for a sizeable percentage of the subjects in the placebo group. Potential placebo responders can be assumed to exist also in the drug treatment group, making it difficult to assess the drug effect. A key drug research focus should be to estimate the percentage of individuals among those who responded to the drug who would not have responded to the placebo (‘Drug Only Responders’). This paper investigates a finite mixture model approach to uncover percentages of up to four potential mixture components: Never Responders, Drug Only Responders, Placebo Only Responders, and Always Responders. Two examples are used to illustrate the modeling, a 12‐week antidepressant trial with a continuous outcome (Hamilton D score) and a 7‐week schizophrenia trial with a binary outcome (illness level). The approach is formulated in causal modeling terms using potential outcomes and principal stratification. Growth mixture modeling (GMM) with maximum‐likelihood estimation is used to uncover the different mixture components. The results point to the limitations of the conventional approach of comparing marginal response rates for drug and placebo groups. It is useful to augment such reporting with the GMM‐estimated prevalences for the four classes of subjects and the Drug Only Responder drug effect estimate. Copyright © 2009 John Wiley & Sons, Ltd.
Bridging concrete and abstract syntaxes in model‐driven engineering: a case of rule languages
Authors: Milanović Milan , Gašević Dragan , Giurca Adrian , Wagner Gerd , Devedžić Vladan
Published: September 2009

The paper covers the problem of bridging the gap between abstract and textual concrete syntaxes of software languages in the model‐driven engineering (MDE) context. This problem has been well studied in the context of programming languages, but due to the obvious difference in the definitions of abstract syntax, MDE requires a new set of engineering principles. We first explore different approaches to defining abstract and concrete syntaxes in the MDE context. Next, we investigate the current state of languages and techniques used for bridging between textual concrete and abstract syntaxes in the context of MDE. Finally, we report on lessons learned in experimenting with the current technologies. In order to provide a comprehensive coverage of the problem under study, we have selected a case of Web rule languages. Web rule languages leverage various types of syntax specification languages; and they are complex in nature and large in terms of the language elements. Thus, they provide us with a realistic analysis framework based on which we can draw general conclusions. Based on the series of experiments that we conducted with the analyzed languages, we propose a method for approaching such problems and report on the empirical results obtained from the data collected during our experiments. Copyright © 2009 John Wiley & Sons, Ltd.
Fetal ventricular tachycardia secondary to long QT syndrome treated with maternal intravenous magnesium: case report and review of the literature
Authors: Simpson J. M. , Maxwell D. , Rosenthal E. , Gill H.
Published: September 2009

Ventricular tachycardia is a very rare fetal arrhythmia accounting for fewer than 2% of fetal tachycardias. We describe a fetus presenting at 30 weeks' gestation with ventricular tachycardia at a rate of 220 beats per min and fetal hydrops. The tachycardia was unresponsive to flecainide but was controlled within 12 h by an intravenous infusion of magnesium to the mother. Despite rapid control of the arrhythmia the fetus developed severe periventricular leukomalacia before birth for which a poor neurological prognosis was given. The baby was delivered preterm at 32 weeks' gestation and died on the sixth day after birth. Long QT syndrome was identified postnatally on the electrocardiogram, and was confirmed by genetic testing which showed a mutation in the KCNH2 gene (p.T613M). Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal Doppler mechanical PR interval: correlation with fetal heart rate, gestational age and fetal sex
Authors: Wojakowski A. , Izbizky G. , Carcano M. E. , Aiello H. , Marantz P. , Otaño L.
Published: September 2009

Objectives

To establish normal fetal values for the mechanical PR interval by pulsed‐wave Doppler at 16–36 weeks of gestation, and to evaluate the influence of fetal heart rate (FHR), gestational age (GA) and fetal sex.

Methods

Fetal mechanical PR intervals were evaluated prospectively by obstetric ultrasound examination. Healthy mothers with sonographically normal fetuses from singleton pregnancies were included. Mechanical PR intervals were measured from simultaneous mitral and aortic Doppler waveforms, from the onset of left atrial contraction (mitral A‐wave) to the onset of left ventricular ejection (aortic pulse wave). Simple and multiple linear regression analyses were performed to examine the correlation between PR interval and GA, FHR and fetal sex.

Results

We evaluated 336 fetuses at 16–36 weeks. The mean ± SD FHR was 143.4 ± 8.3 beats per min (bpm). The PR intervals had a typical Gaussian distribution with a mean ± SD of 122.4 ± 10.3 ms. Robust linear regression showed that the PR increased by about 0.40 ms (95% CI, 0.22–0.58) per gestational week (P < 0.001), and this relationship remained after adjustment for FHR and fetal sex. PR intervals diminished by 1.4 (95% CI, 0.75 to 2.0) ms for each 5 bpm increase in FHR (P < 0.001), independently of GA and fetal sex. No fetal sex differences were observed.

Conclusions

We provide normal fetal values for the mechanical PR interval at 16–36 weeks of gestation. Mechanical PR intervals in normal fetuses are influenced by GA and FHR independently, and both variables should be taken into account when evaluating fetuses at risk for congenital heart block. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Assessing nanotoxicity in cells in vitro
Authors: Hillegass Jedd M. , Shukla Arti , Lathrop Sherrill A. , MacPherson Maximilian B. , Fukagawa Naomi K. , Mossman Brooke T.
Published: September 2009

Nanomaterials are commonly defined as particles or fibers of less than 1 µm in diameter. For these reasons, they may be respirable in humans and have the potential, based upon their geometry, composition, size, and transport or durability in the body, to cause adverse effects on human health, especially if they are inhaled at high concentrations. Rodent inhalation models to predict the toxicity and pathogenicity of nanomaterials are prohibitive in terms of time and expense. For these reasons, a panel of in vitro assays is described below. These include cell culture assays for cytotoxicity (altered metabolism, decreased growth, lytic or apoptotic cell death), proliferation, genotoxicity, and altered gene expression. The choice of cell type for these assays may be dictated by the procedure or endpoint selected. Most of these assays have been standardized in our laboratory using pathogenic minerals (asbestos and silica) and non‐pathogenic particles (fine titanium dioxide or glass beads) as negative controls. The results of these in vitro assays should predict whether testing of selected nanomaterials should be pursued in animal inhalation models that simulate physiologic exposure to inhaled nanomaterials. Conversely, intrathoracic or intrapleural injection of nanomaterials into rodents can be misleading because they bypass normal clearance mechanisms, and non‐pathogenic fibers and particles can test positively in these assays. WIREs Nanomed Nanobiotechnol 2010 2 219–231

This article is categorized under:

Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials
Synergistic Behavior Between Zwitterionic Surfactant α‐Decylbetaine and Anionic Surfactant Sodium Dodecyl Sulfate
Authors: Wang Ze‐yun , Zhang Shu‐fen , Fang Yun , Qi Li‐yun
Published: September 2009

Here, we present experimental surface tension isotherms of mixed solutions of a zwitterionic surfactant α‐decylbetaine (DB) and an anionic surfactant sodium dodecyl sulfate (SDS) in different molar ratios. These mixed solutions show a composition dependency with respect to both surface tension effectiveness and critical micelle concentration. The pseudo‐regular solution theory has been used to evaluate the interaction parameters in the micelle, βm and at the surface, βs. The results revealed that the mixed solutions of DB/SDS behave synergistically in both surface tension reduction effectiveness and mixed micelle formation at all mole fractions investigated. The values of adsorption area per surfactant molecule at air/solution interface were estimated, which provides some useful information on evaluating the interaction between DB and SDS in mixed adsorbed monolayers. The solubilization behaviors of toluene in DB/SDS mixed solutions were also investigated to help in understanding the structure of mixed micelles of DB and SDS.
Diameters of microtubules change during rotation of the lipotubuloids of Ornithogalum umbellatum stipule epidermis as a result of varying protofilament monomers sizes and distance between them
Authors: Kwiatkowska Maria , Stępiński Dariusz , Popłońska Katarzyna
Published: September 2009

Microtubules in lipotubuloids of the Ornithogalum umbellatum stipule epidermis cells change their diameters depending on the motion of the cytoplasmic domains rich in microtubules and lipid bodies. Microtubules fixed during rotary and progressive motion of the lipotubuloids composed of the same number of protofilaments fall into two populations – wide (43–58 nm) and narrow (24–39 nm) in size. Following blockage of the motion with 2,4‐dinitrophenol (DNP), the range of this diversity is smaller, microtubules become a medium‐sized population (34–48 nm). When DNP is removed and the motion reactivated, 2 populations of microtubules reappear. Analysis of the structure of the microtubule wall revealed that changes in the microtubule diameters resulted from varying distances between the adjacent protofilaments, and stretching and compression of tubulin subunits in the protofilaments.

A supposition has been put forward that the changes in the sizes of O. umbellatum microtubule diameters: 1) are connected with the interactions between microtubules and actin microfilaments lying along these microtubules; 2) can be the driving force of the rotary motion of lipotubuloids.
Cytotoxicity of calotropin is through caspase activation and downregulation of anti‐apoptotic proteins in K562 cells
Authors: Wang Shih‐Chung , Lu Mei‐Chin , Chen Hsiu‐Lin , Tseng Hsing‐I , Ke Yu‐Yuan , Wu Yang‐Chang , Yang Pei‐Yu
Published: September 2009

Calotropin is one of cardenolides isolated from milkweed used for medicinal purposes in many Asian countries. Whereas calotropin possesses cytotoxicity against several cancer cells, the mechanisms of action remain unclear. We set out to evaluate the cytotoxic mechanism of calotropin on human chronic myeloid leukemia K562 cells. Calotropin inhibited the growth of K562 cells in a time‐ and dose‐dependent manner by G2/M phase arrest. It upregulated the expression of p27 leading to this arrest by downregulating the G2/M regulatory proteins, cyclins A and B, and by upregulating the cdk inhibitor, p27. Furthermore, it downregulated anti‐apoptotic signaling (XIAP and survivin) and survival pathways (p‐Akt and NFκB), leading to caspase‐3 activation which resulted in the induction of apoptosis. In all, calotropin exerted its anticancer activity on K562 cells by modulating the pro‐survival signaling that leads to induction of apoptosis.
Bak's work on theK-theory of rings
Authors: Hazrat Roozbeh , Vavilov Nikolai
Published: September 2009

This paper studies the work of Bak in algebra and (lower) algebraicK-theory and some later developments stimulated by them. We present an overview of his work in these areas, describe the setup and problems as well as the methods he introduced to attack these problems and state some of the crucial theorems. The aim is to analyse in detail some of his methods which are important and promising for further work in the subject. Among the topics covered are, unitary/general quadratic groups over form rings, structure theory and stability for such groups, quadraticK2and the quadratic Steinberg groups, nonstableK-theory and localisation-completion, intermediate subgroups, congruence subgroup problem, dimension theory and surgery theory.
Periodicity theorems and conjectures in hermitian K-theory
Authors: Karoubi Max
Published: September 2009

In this appendix to [4], we state a periodicity conjecture using form parameters. This conjecture contains as particular case the fundamental theorem in hermitian K-theory proved in [6] but also some results of Bak [1], Barge and Lannes [2], Sharpe [8], for lower hermitian K-groups. The interest of this conjecture lies also in the parallel use of hermitian forms and quadratic forms with form parameters introduced by Bak.
Development of a dynamic mathematical model for investigating mammary gland metabolism in lactating cows
Authors: VOLPE V. , CANT J. P. , BOSTON R. C. , SUSMEL P. , MOATE P.
Published: September 2009

A dynamic mathematical model of a closed mammary system in lactating cows was developed to incorporate the setpoint concept of tissue activity, using equations where nutrient supply and absorption are locally regulated so as to maintain a given rate of milk protein yield. The model consists of 12 differential equations, 11 of which are concerned with intracellular biochemical compartments and one describes the volume of tissue actively perfused by blood (AP). The intracellular compartments are: amino acids (AAs), acetate, fatty acids (FAs), β-hydroxybutyrate, glucose-6-phosphate, fructose-6-phosphate, phospho-glyceraldehyde, pyruvate, mitochondrial acetyl-CoA, adenosine triphosphate (ATP) and adenosine diphosphate (ADP). The model simulates mechanisms which are aimed at reproducing and, thereby, explain variations in mammary plasma flow (MPF) observed experimentally. The AP changes according to variations in the metabolic status or in the metabolic requirements of the gland. Should the tissue energy charge (i.e. ATP/ADP ratio) exceed a baseline ratio, then AP decreases and consequently MPF declines. Conversely, when milk protein yield increases, AP increases and MPF rises. In the present model, AA uptake by the mammary gland is inhibited by intracellular AAs. It is also assumed that, when milk protein yield diminishes, the respiratory chain and ATP synthesis become uncoupled and consequently ATP yield is reduced. Model evaluation included behavioural analysis and sensitivity analysis. Behaviour analysis was conducted to test whether the model mechanisms reproduced the scenarios from which the model hypotheses were developed, and took into consideration: an increase in arterial glucose concentration (HIGLC), increases in arterial concentrations of non-esterified FAs, triacylglycerol and β-hydroxybutyrate (HIFAT), a 50% reduction of arterial histidine concentration (LOHIS), and a hyperinsulinaemic euglycaemic clamp (HIINS). Both HIGLC and HIFAT resulted in a decrease in MPF and in milk protein yield; moreover, the scenario HIGLC also produced a notable decrease in the extraction of glucose. The scenario LOHIS resulted in increased MPF and extraction of His from plasma. However these responses were not sufficiently large to prevent a severe reduction of milk protein yield which was accompanied by a reduction in the extraction of other essential AAs. The scenario HIINS resulted in an increase of MPF and of milk protein yield, in the extraction of His and of other essential AAs. Model sensitivity analysis focused on variation of both affinity and inhibition constants of some of the Michaelis–Menten equations. Improvements in model structure and directions for future research suggested by the modelling analysis are discussed.
Wild Life and its Preservation in Ceylon
Authors: Norris C. E.
Published: September 2009

Ceylon, for its size, has been richly endowed with a wealth of indigenous fauna; many species that have been scientifically separated from their close relatives on the Indian continent are peculiar to the island.
Bird Study in New Zealand
Authors: Moncrieff Perrine
Published: September 2009

New Zealand might be described as a land of surprises done up in very small parcels. It has many minerals, but these, owing to past upheavals, are seldom in payable quantities. Distributed over the country in pockets, they affect the soil which, in turn, has a bearing upon plant and bird life. Due to this and climatic conditions a botanist will find different plants as he passes from Norfolk Island towards the Antarctic. Some of them occur in one small area and nowhere else.
Saving the Trumpeter Swan
Authors: Davies Freda
Published: September 2009

Around the turn of the twentieth century, North American conservationists embarked on an intensive campaign to prevent the Trumpeter Swan (Cygnus buccinator) from following the Passenger Pigeon into extinction.
The Walrus
Authors: Matheson Colin
Published: September 2009

The Walrus is confined to the northern circumpolar regions, its range northward apparently extending to the limit of perpetual ice. Now rare in Iceland, Odobenus rosmarus is stated to be still not unfamiliar in Hudson Bay, Davis Strait, and Baffin Bay north to Ellesmere Land, the coasts of Greenland, Spitsbergen, Novaia Zemlia, and the western part of the north coast of Siberia; in all of which regions, however, persecution has greatly diminished its numbers. The species does not extend along the far eastern part of the north Siberian coast, and Walrus are not met with again until the north-eastern extremity of Siberia is reached. Here the Pacific Walrus, which differs somewhat from that of the Atlantic side and is regarded as a distinct species, Odobenus obesus, is reported from Cape Chelagskai, in longitude 170° E., along the Siberian coast as far as northern Kamschatka south to latitude 60°, also on some of the islands in the Bering Sea, and on the opposite coast of Alaska south to about latitude 55° and eastward to Point Barrow. Here again a long gap along the Arctic coast of North America, from Point Barrow in longitude 158° W. to the western shore of Hudson Bay in longitude 97° W., separates the Pacific from the Atlantic Walrus.
The Apes of Gibraltar
Authors: Russell Claud
Published: September 2009

It is, I think, common knowledge that in the course of the war the defences of Gibraltar were strengthened, the garrison reinforced, and the civilian population largely evacuated. But there was another notable measure taken which, so far as I know, has escaped publicity. It is not easy to come by information on the affairs of Gibraltar, but the local belief is that during a brief official visit to the Rock, Mr. Churchill became aware that the famous Apes had so decreased in numbers as to make their continued existence precarious. Conscious, no doubt, of our Society's good purpose, and aware, perhaps, of the age-long belief that if ever the Apes should come to an end a like fate would befall our possession of Gibraltar, the Prime Minister gave an urgent order that the Apes should be increased by such a number as would ensure their preservation. This was done by an importation of monkeys of the same species (Macaca, sylvana) from Barbary, across the Straits, and these are now, to all appearance, well established in their new home. Their location is about half-way up the Rock, and accessible by road. A soldier of the garrison has charge of them and notice boards here and there request visitors “not to touch or feed the roaming Apes”, but in practice no objection is made if anyone wishes to give them fruit. Judging by the number of young ones, the Apes have multiplied since their arrival and the total colony appears to amount now to about twenty.
Beauty and Fantasy in Nairobi Park
Authors: Tomkinson Robin
Published: September 2009

If you have never seen the African animals except in zoos, and have always longed to see them wild, the Nairobi National Park is a sort of paradise. At first it is hard to believe that you are not in the middle of a wonderful dream, though as with many such dreams, there is grimness lurking in the background in the form of Vultures, Hyænas, and, of course, Lions.

Though the Park is quite small, only about 40 square miles, the number and variety of animals is amazing, especially considering that during the war it was an army training ground, so hardly a peaceful place for them. But now, driving slowly along, you find hundreds of beautiful and fantastic beasts strolling unconcernedly around you, for they have found that they are safe from men in cars, if not from Lions.
The Future of the African Fauna
Authors: Worthington E. B.
Published: September 2009

Captain Keith Caldwell, in his admirable report of a faunal survey in Eastern and Central Africa conducted in 1947, says: “… Were one of the old hunters who operated fifty years ago to visit Eastern Africa to-day, he would find vast districts in which he used to shoot completely denuded of game; in fact, it is probable that the game areas have been reduced by half, and the game within many of those left by 75 per cent.”

That, I think, is a fair estimate: a reduction of the fauna of Eastern and Central Africa to between a half and one-quarter of what it was half a century ago. The same applies more or less, but mostly more, to the whole of Africa south of the Sahara. The question before us now is what will be the state of this unique assemblage of fauna, including many species found nowhere else in the world, at the end of the next half-century?
The Cat
Authors: Zeuner F. E.
Published: September 2009

Among the domestic pets kept in the towns of England, the cat probably tops the list so far as numbers go. But unlike other domesticated animals its association with man has been relatively short and, in spite of the mouse-catching propensities of some breeds, domestication was in this case only in part guided by economic considerations.
Jubaland Safari
Authors: Sorrell D. S.
Published: September 2009

We left Kismayu by safari truck on the morning of 3rd March, 1950, with the intention of touring the district up to the Kenya border.

We decided to take the Afmadu road, but saw only Dik-Dik on the way, mostly of the greyish Kirk's variety although a few pairs of the prettier Phillips's Dik-Dik were to be seen also. These beautifully-proportioned tiny antelope multiply rapidly in dry bush country such as this, in spite of their many enemies. I have surprised hawks and eagles on a dik-dik “kill” on occasions, and by the neat hole in their skull it has been only too obvious how they were struck down.
The Chillingham Cattle
Authors: Gee E. P.
Published: September 2009

The last mention of the famous herd of Chillingham Cattle in the Journal of this Society was made in Part XVI published in April, 1932. At that time an appeal was being launched by three Trustees appointed for the purpose by the Council of the Zoological Society of London; and a lease for seven years at a rental of £500 per annum of the Park at Chillingham Castle in Northumberland was taken from the Earl of Tankerville, with the object of preserving the cattle. The present Earl, who succeeded to the title in 1931, was unable to maintain the herd at his own expense owing to the heavy and ever increasing burden of taxation. The Zoological Society of London contributed £100 annually for seven years, and the rest was found by public subscriptions.
Interlude in Austria
Authors: Boyle A. M. V.
Published: September 2009

After the technical meeting of the International Union for the Protection of Nature, many of the participants and their wives were able to take part in the excursions arranged by the local organizing committee. On the afternoon of 18th September, we visited the Salzkammergut, a district east of Salzburg which could be compared to our lake district. Here is a network of beautiful lakes with steep wooded hills and sheer cliffs dropping to the blue water. At the Fuschl See, our first stop, Ribbentrop and Ciano had had many meetings during the war in the castle hotel overlooking the lake. The near-by pastures were covered with pale mauve meadow saffron, and beside the path we saw Gentiana germanica and a fine group of the shaggy ink cap fungus (Coprinus comatus). We went on to the Wolfgangsee and Mondsee, returning to Salzburg in the evening. Later my husband and I spent a few days on the shore of the Wolfgangsee and were able to explore at leisure.
The Behaviour of Seladang (Bibos gaurus)
Authors: Ogilvie C. S.
Published: September 2009

Reaction to the Presence of Man and of Tiger.—Bull seladang grazing in the open seldom raise their heads from the serious business of filling their maws, but leave watch-dog duties to the cows. The latter seldom keep their heads down long, and it is on this account that care must be taken when stalking a herd up wind in the open. Some cow almost always has her head up looking about. I say “looking about”, for they do not generally try the wind unless some strange or dangerous scent comes to them; then all, even the bulls, are on their toes. When an unfavourable wind is received they first throw up their heads and face into the wind, raising their noses; after a good inspiration in this position, they swing their heads sharply first to one side, then after a short pause to the other side, testing the wind. They may repeat this action several times before being certain. From this they are able to determine the direction in which any danger may lie. If it is a scent denoting the presence of man they hesitate not on the order of going, stampeding away from the dreaded scent for perhaps seventy or a hundred yards. After their initial rush they pull up for a short pause making sure the danger is not on their tails. If the danger is not so close, they slip quietly away at a fast walk; if the source of danger is not following they keep this up, perhaps, for several miles, before they pull up for a real breather, but still remain very wary.