bluuebunny/crossref_metadata_2025 huggingface dataset:
The Financial Management of Unit Trust and Investment Companies
Authors: Mehta S.J.B. , Abbott M.G. , Addison D.T. , Dodhia M. , Hitchen C.J. , Oddie A.J. , Poulding M.R. , Riddington D.M.
Published: June 2011

The paper describes the application of actuarial techniques to the financial management of unit trusts and other collective investment schemes. The main features of collective investment schemes are described and the financial issues facing managers of these schemes are highlighted. The unit trust industry in particular is facing a number of potentially significant changes and the paper explores the areas in which the actuarial profession can add value to this industry.
Merging With-Profits and Unit-Linked Life Funds in a Proprietary Company: Actuarial Considerations Based on a Case Study
Authors: Paul R.M.
Published: June 2011

The text of this paper, together with the abstract of the discussion held by the Faculty of Actuaries on 19 February 1996, are printed in British Actuarial Journal, 2, III, pages 623-702.
An Actuarial Theory of Option Pricing
Authors: Clarkson R.S.
Published: June 2011

Using an empirical approach to capital market returns analogous to that used for mortality rates by Halley more than three centuries ago to establish life assurance on a sound and scientific footing, a theory of option pricing is built up in terms of the same three key components as for life assurance premiums, namely the expected cost of claims, an allowance for expenses, and a contingency margin as a reserve against the risk of insolvency. The dimensionality of the process describing security returns to any future point in time is increased from two to three by the addition of systematic variability around ‘central values’ to the standard descriptors of expected return and variance of return. It is shown that this approach, which involves only common sense principles and elementary mathematics, has important theoretical, practical and regulatory advantages over the Black-Scholes and related methodologies of modern finance theory.
Address by the President of the Faculty of Actuaries. The World Needs Actuaries
Authors: Bowie Ronald Stewart
Published: June 2011

This presidential address looks at the current state of affairs, the opportunities and threats to our traditional areas of interest and the importance of developing in wider fields. It pays tribute to all the volunteers who help make it the organisation that it is whilst highlighting the need for all Fellows and students to be engaged with its future.
Longevity: A ‘Simple’ Stochastic Modelling of Mortality
Authors: Browne B. , Duchassaing J. , Suter F.
Published: June 2011

All UK insurers exposed to longevity risk need to perform stress tests for their Individual Capital Assessment (ICA). Some have put in place deterministic models which are arguably too simple; others have developed stochastic models that can be demanding and complex.

This paper presents a simple model to turn any deterministic mortality scenario into a stochastic model. We propose a simple model of stochastic variation that is easy to explain and to implement, which could be an alternative to and/or complete some of the well known models. The model can be applied to any best estimates of future mortality rates, as it aims to describe how longevity behaves around the projected expected values.

The paper proposes a possible calibration on the England and Wales population mortality that produces a minimum indication of possible future variation and uses the results to validate the model's assumptions. Using sample portfolios and the stochastic model, we can simulate cash flows to determine the distribution of the net present values (NPV) of annuity outgo.
Uncoupled Cerebral Blood Flow and Metabolism after Severe Global Ischemia in Rats
Authors: Singh Narendra C. , Kochanek Patrick M. , Schiding Joanne K. , Melick John A. , Nemoto Edwin M.
Published: June 2011

In a rat model of complete global brain ischemia (neck tourniquet) lasting either 3 min or 20 min, we monitored global CBF (sagittal sinus H2 clearance) and CMRO2 for 6 h to test the hypothesis that delayed postischemic hyperemia and uncoupling of CBF and CMRO2 occur depending on the severity of the insult. Early postischemic hyperemia occurred in both the 3-min and 20-min groups ( p < 0.05 vs. baseline values) and resolved by 15 min. Hypoperfusion occurred in the 3-min group between 15 and 60 min postischemia (≈23% reduction), and in the 20-min group from 15 to 120 min postischemia (≈50% reduction) ( p < 0.05), and then resolved. CMRO2 was not significantly different from baseline at any time after ischemia in the 3-min group. After 20 min of ischemia, however, CMRO2 was decreased (≈60%) throughout the postischemic period ( p < 0.05). At 5 min after ischemia, CBF/CMRO2 was increased in both groups but returned to baseline from 60 to 120 min postischemia. In the 3-min group, CBF/CMRO2 remained at baseline throughout the rest of the experiment. However, in the 20-min group, CBF/CMRO2 once again increased (≈100%), reaching a significant level at 180 min and remaining so for the rest of the 6-h period ( p < 0.05). These data demonstrate biphasic uncoupling of CBF and CMRO2 after severe (20 min) global ischemia in rats. This relatively early reemergence of CBF/CMRO2 uncoupling after 180 min of reperfusion is similar to that observed after prolonged cardiac arrest and resuscitation in humans.
Theoretical approach to study the effect of free volumes on the physical behavior of polymer stabilized ferroelectric liquid crystal molecules
Authors: Lahiri T. , Majumder T. Pal
Published: June 2011

It was clearly indicative that the polymer chains make a tremendous interaction with the tilt angle in case of a polymer stabilized ferroelectric liquid crystal (PSFLC). After suitable consideration of such interaction, we expanded the Landau free energy for a PSFLC system. We theoretically demonstrated the effect of free volumes, which expected to create bulk self-energy, on the physical functionalities of a PSFLC system. Then we obtained spontaneous polarization, tilt angle, rotational viscosity and dielectric constant strongly correlated with the assumed interactions. We also observed a shift of transition temperature highly influenced by this interaction between polymer network and liquid crystal molecules. A microscopical picture of this polymer-liquid crystal interaction is provided in view of the free volume charge density present in the composite system.
Ion-beam-induced damage formation in CdTe
Authors: Rischau C. W. , Schnohr C. S. , Wendler E. , Wesch W.
Published: June 2011

Damage formation in 〈111〉- and 〈112〉-oriented CdTe single crystals irradiated at room temperature and 15 K with 270 keV Ar or 730 keV Sb ions was investigated in situ using Rutherford backscattering spectroscopy (RBS) in channeling configuration. Defect profiles were calculated from the RBS spectra using the computer code DICADA and additional energy-dependent RBS measurements were performed to identify the type of defects. At both temperatures no formation of a buried amorphous layer was detected even after prolonged irradiation with several 1016 ions/cm2. The fact that CdTe is not rendered amorphous even at 15 K suggests that the high resistance to amorphization is caused by the high ionicity of CdTe rather than thermal effects. The calculated defect profiles show the formation of a broad defect distribution that extends much deeper into the crystal than the projected range of the implanted ions at both temperatures. The post-range defects in CdTe thus do not seem to be of thermal origin either, but are instead believed to result from migration driven by the electronic energy loss.
Asymmetric domain wall depinning under current in spin valves with perpendicular anisotropy
Authors: Park S. , Nguyen N. M. , Burrowes C. , Fullerton E. E. , Chappert C. , Prejebeanu L. , Garcia-Sanchez F. , Ravelosona D.
Published: June 2011

We have studied the current induced domain wall depinning from an artificial constriction in Co/Ni multilayer spin valves with perpendicular magnetic anisotropy. We find that the variation in the depinning field under current is strongly dependent on the direction of propagation of the domain wall. This asymmetry arises from the stray dipolar fields generated by the reference layer, which plays an important role in influencing the magnetization reversal process under current. In particular, it can favor a nucleation process instead of domain wall motion, which may be amplified by the current.
Time-resolved luminescence spectroscopy of self-trapped excitons in ladder type Br-bridged Pt complexes
Authors: Suemoto T. , Nakao H. , Nakajima M. , Kitagawa H.
Published: June 2011

The out-of-phase and in-phase ladder type Br-bridged Pt complexes are investigated by time-resolved luminescence spectroscopy in pico- and femtosecond time regions. The observed luminescence spectra have peaks at 0.87 and 0.94 eV in out-of-phase and in-phase materials, respectively, and are assigned to self-trapped excitons. The wave-packet oscillations in self-trapped excitons (STE) are observed in both materials. The time-evolution curves are analyzed in terms of the secondary radiation theory of strongly coupled electron-phonon system. The period and dephasing time of oscillations as well as the lifetime and spectral shape of the STE luminescence are determined. The fast dephasing or cooling of the wave-packet motion observed in the in-phase type complex is ascribed to inter-chain interactions within the ladder.
Enhancement of the magneto-optical performance of Sr(Ti0.6−xGaxFe0.4)O3 perovskite films by Ga substitution
Authors: Jiang Peng , Bi Lei , Kim Dong Hun , Dionne G. F. , Ross C. A.
Published: June 2011

Epitaxial films of ferromagnetic single-phase perovskite (Ti0.6−xGaxFe0.4)O3 (x≤0.6) were grown on (001) oriented (La,Sr)(Al,Ta)O3 substrates by pulsed laser deposition. The films had an out-of-plane magnetic easy axis which is attributed to magnetoelastic effects. Ga lowered the optical absorption of the film, the Faraday rotation, and the magnetization but increased the magneto-optical figure of merit. The figure of merit for x=0.4 was 3.5±0.3 deg/dB, at least approximately three times greater than the value at x=0, and the optical loss at 1550 nm wavelength was 0.012–0.015 dB/μm.
Reexamining protein–protein and protein–solvent interactions from Kirkwood-Buff analysis of light scattering in multi-component solutions
Authors: Blanco Marco A. , Sahin Erinc , Li Yi , Roberts Christopher J.
Published: June 2011

The classic analysis of Rayleigh light scattering (LS) is re-examined for multi-component protein solutions, within the context of Kirkwood-Buff (KB) theory as well as a more generalized canonical treatment. Significant differences arise when traditional treatments that approximate constant pressure and neglect concentration fluctuations in one or more (co)solvent/co-solute species are compared with more rigorous treatments at constant volume and with all species free to fluctuate. For dilute solutions, it is shown that LS can be used to rigorously and unambiguously obtain values for the osmotic second virial coefficient (B22), in contrast with recent arguments regarding protein interactions deduced from LS experiments. For more concentrated solutions, it is shown that conventional analysis over(under)-estimates the magnitude of B22 for significantly repulsive(attractive) conditions, and that protein-protein KB integrals (G22) are the more relevant quantity obtainable from LS. Published data for α–chymotrypsinogen A and a series of monoclonal antibodies at different pH and salt concentrations are re-analyzed using traditional and new treatments. The results illustrate that while traditional analysis may be sufficient if one is interested in only the sign of B22 or G22, the quantitative values can be significantly in error. A simple approach is illustrated for determining whether protein concentration (c2) is sufficiently dilute for B22 to apply, and for correcting B22 values from traditional LS regression at higher c2 values. The apparent molecular weight M2, app obtained from LS is shown to generally not be equal to the true molecular weight, with the differences arising from a combination of protein-solute and protein-cosolute interactions that may, in principle, also be determined from LS.
Sulfur passivation effect on HfO2/GaAs interface: A first-principles study
Authors: Wang Weichao , Gong Cheng , Shan Bin , Wallace Robert M. , Cho Kyeongjae
Published: June 2011

The impact of sulfur passivation on the structural and electronic properties of the HfO2/GaAs interface is investigated by density functional theory with a hybrid functional. The gap states at the HfO2/GaAs interface arise from three major contributions: Ga 3+ and partial oxidation, As–As dimers, and Ga dangling bonds. By introducing S atoms at the interface, the removal of the gap states within the lower half of the GaAs band gap is observed, while the gap states in the upper half are pushed upward by ∼0.15 eV.
A hierarchy of Garnier-Rosochatius systems
Authors: Xia Baoqiang
Published: June 2011

A hierarchy of Hamiltonian systems including the Garnier-Rosochatius system as the first member is introduced. This hierarchy of Hamiltonian systems is proved to be completely integrable, and the corresponding flows are linearized on the Jacobi variety of the associated hyperelliptic curve. In addition, a relation between these flows and the KdV equation is found, and the connection with finite gap solution of KdV equation is shown.
Strategies for dynamic soft-landing in capacitive microelectromechanical switches
Authors: Jain Ankit , Nair Pradeep R. , Alam Muhammad A.
Published: June 2011

Electromechanical dielectric degradation associated with the hard landing of movable electrode is a technology-inhibiting reliability concern for capacitive RF-MEMS switches. In this letter, we propose two schemes for dynamic soft-landing that obviate the need for external feedback circuitry. Instead, the proposed resistive and capacitive braking schemes can reduce impact velocity significantly without compromising other performance characteristics like pull-in voltage and pull-in time. Resistive braking is achieved by inserting a resistance in series with the voltage source whereas capacitive braking requires patterning of the electrode or the dielectric. Our results have important implications to the design and optimization of reliability aware electrostatically actuated MEMS switches.
On the correlation between bond-length change and vibrational frequency shift in halogen-bonded complexes
Authors: Wang Weizhou , Zhang Yu , Ji Baoming , Tian Anmin
Published: June 2011

The C-Hal (Hal = Cl, Br, or I) bond-length change and the corresponding vibrational frequency shift of the C-Hal stretch upon the C-Hal ⋯Y (Y is the electron donor) halogen bond formation have been determined by using density functional theory computations. Plots of the C-Hal bond-length change versus the corresponding vibrational frequency shift of the C-Hal stretch all give straight lines. The coefficients of determination range from 0.94366 to 0.99219, showing that the correlation between the C-Hal bond-length change and the corresponding frequency shift is very good in the halogen-bonded complexes. The possible effects of vibrational coupling, computational method, and anharmonicity on the bond-length change-frequency shift correlation are discussed in detail.
Modification of microneedles using inkjet printing
Authors: Boehm R D , Miller P R , Hayes S L , Monteiro-Riviere N A , Narayan R J
Published: June 2011

In this study, biodegradable acid anhydride copolymer microneedles containing quantum dots were fabricated by means of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing. Nanoindentation was performed to obtain the hardness and the Young's modulus of the biodegradable acid anhydride copolymer. Imaging of quantum dots within porcine skin was accomplished by means of multiphoton microscopy. Our results suggest that the combination of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing enables fabrication of solid biodegradable microneedles with a wide range of geometries as well as a wide range of pharmacologic agent compositions.
Prevalence and Predictors of Antibiotic Use in Community-Based Elderly in Ontario, Canada
Authors: Mertz Dominik , Tjam Erin Y. , Poss Jeff , Hirdes John P. , Arai Bruce , Johnstone Jennie , Jantzi Micaela , Loeb Mark
Published: June 2011

Little is known about antibiotic use in the elderly receiving home care. We found that 6,873 (5.4%) of 126,339 home care patients in Ontario received antibiotic treatment; 26% of the antibiotics administered were fluoroquinolones. Antibiotic treatment was most frequent in patients less than 65 years of age and among those with a poorer health status.
A Practical Method for Surveillance of Novel H1N1 Influenza Using Automated Hospital Data
Authors: Chopra Teena , Binienda Juliann , Mohammed Mazin , Shyamraj Rushyal , Long Patrick , Bach David , Carlton Cristi , Peters Susan , Lephart Paul , Alangaden George , Dhar Sorabh , Marchaim Dror , Schreiber Michelle , Kaye Keith S.
Published: June 2011

We report a surveillance method for influenza that is based on automated hospital laboratory and pharmacy data. During the 2009 H1N1 influenza pandemic, this method was objective, easy to perform, and utilized readily available automated hospital data. This surveillance method produced results that correlated strongly with influenza-like illness surveillance data.
XeBr excilamp based on a non-toxic component mixture
Authors: Kelman V A , Shpenik Yu O , Zhmenyak Yu V
Published: June 2011

This paper presents the results of experimental studies on obtaining UV luminescence of XeBr* molecules at the excitation of a non-toxic Xe–CsBr gas-vapour mixture by a longitudinal pulse-periodic discharge. Effective UV emission yield of the exciplex XeBr* molecules (spectral maximum at 282 nm) is observed within a wide range of excitation conditions. The spectral distribution in the UV emission under the optimal excitation conditions does not differ essentially from that in other XeBr excilamps based on toxic components. The emission of the B → X band of the XeBr* molecules provides the main contribution to the total power of the discharge UV emission. The determined average power of the UV emission for the experimental discharge tube is 12 W at an efficiency of 1%. Spectral, power-related and time-dependent parameters of the laboratory excilamp are presented for a wide range of excitation parameters. A new mechanism of exciplex molecule formation at the excitation of a rare gas/alkali halide vapour mixture is discussed.
Experimental evaluation of CaO, SrO and BaO sputtering yields by Ne+ or Xe+ ions
Authors: Yoshimura Satoru , Hine Kiyohiro , Kiuchi Masato , Hashimoto Jun , Terauchi Masaharu , Honda Yosuke , Nishitani Mikihiko , Hamaguchi Satoshi
Published: June 2011

Barrier coating materials used in plasma display panel (PDP) cells strongly affect the discharge voltages. Although magnesium oxide (MgO) is widely used for barrier coating in the current generation of commercial PDP cells, other alkaline earth oxides have been studied as alternatives and indeed some of them are now known to have lower discharge breakdown voltages for PDP cells, which would increase the energy efficiency of the cells. On the other hand, the resistance against physical sputtering is another critical parameter for barrier coating. In this work, sputtering yields of CaO, SrO and BaO by monochromatic Ne or Xe ion beams are obtained experimentally as functions of beam energy in the range 100–300 eV. Despite the large differences in mass among the targets and incident ions, sputtering yields are found to be similar in magnitude among them for a given incident energy.
Management of COPD
Authors: Potter Andrew , Wilkinson Alex
Published: June 2011

Every GP and Associate in Training (AiT) will be closely involved in the ongoing disease management of patients with chronic obstructive pulmonary disease (COPD). It is one of the most common chronic diseases in the UK and the majority of care is based in the community. Therefore, all GPs and trainees should have a comprehensive evidence-based and up-to-date knowledge of the management of this condition. Moreover, chronic management of COPD involves a multidisciplinary approach and the GP should be at the centre of this. This article aims to review current management of COPD, using latest national guidelines and best available evidence. It describes the different components of the multidisciplinary management of this condition and provides practical tips for GPs and AiTs.
Transient Ischaemic Attacks
Authors: Wainman Paul K.
Published: June 2011

Atransient ischaemic attack (TIA) is defined as an acute neurological event causing loss of focal cerebral or ocular function lasting less than 24 hours and thought to be due to inadequate cerebral or ocular blood supply. More than 46 000 people suffer a TIA in the UK each year. Of these, approximately 10% will go on to suffer a stroke within the next 5 days and 20% within the next 4 weeks. The importance of this diagnosis both to the individual and to the National Health Service (NHS) is therefore huge. This article will discuss the diagnosis and management of TIA in general practice including primary and secondary preventative strategies.
Isoflurane Decreases Self-renewal Capacity of Rat Cultured Neural Stem Cells
Authors: Culley Deborah J. , Boyd Justin D. , Palanisamy Arvind , Xie Zhongcong , Kojima Koji , Vacanti Charles A. , Tanzi Rudolph E. , Crosby Gregory
Published: June 2011

Background

In models, isoflurane produces neural and behavioral deficits in vitro and in vivo. This study tested the hypothesis that neural stem cells are adversely affected by isoflurane such that it inhibits proliferation and kills these cells.

Methods

Sprague-Dawley rat embryonic neural stem cells were plated onto 96-well plates and treated with isoflurane, 0.7, 1.4, or 2.8%, in 21% oxygen for 6 h and fixed either at the end of treatment or 6 or 24 h later. Control plates received 21% oxygen under identical conditions. Cell proliferation was assessed immunocytochemically using 5-ethynyl-2'-deoxyuridine incorporation and death by propidium iodide staining, lactate dehydrogenase release, and nuclear expression of cleaved caspase 3. Data were analyzed at each concentration using an ANOVA; P < 0.05 was considered significant.

Results

Isoflurane did not kill neural stem cells by any measure at any time. Isoflurane, 1.4 and 2.8%, reduced cell proliferation based upon 5-ethynyl-2'-deoxyuridine incorporation, whereas isoflurane, 0.7%, had no effect. At 24 h after treatment, the net effect was a 20-30% decrease in the number of cells in culture.

Conclusions

Isoflurane does not kill neural stem cells in vitro. At concentrations at and above the minimum alveolar concentrations required for general anesthesia (1.4 and 2.8%), isoflurane inhibits proliferation of these cells but has no such effect at a subminimum alveolar concentration (0.7%). These data imply that dosages of isoflurane at and above minimum alveolar concentrations may reduce the pool of neural stem cells in vivo but that lower dosages may be devoid of such effects.
Nucleotide Sequence of the Na+/H+ Exchanger‐8 in Patients With Congenital Sodium Diarrhea
Authors: Baum Michel , Martin Martin G. , Booth Ian W. , Holmberg Christer , Twombley Katherine , Zhang Qiuyu , Gattineni Jyothsna , Moe Orson
Published: June 2011

Sodium absorption by the intestine is mediated by brush border Na+/H+ exchangers, which include the NHE3 and NHE8 isoforms. We demonstrated a maturational decrease in NHE8 and increase in NHE3 in mouse intestine mRNA abundance and brush border membrane protein abundance, indicating a developmental switch of isoforms. Congenital sodium diarrhea is a rare autosomal recessive disorder characterized by polyhydramnios, hyponatremia, metabolic acidosis, and diarrhea with a high sodium content. Previous studies using intestinal brush border membrane vesicles from patients with this disorder have demonstrated a decrease in Na+/H+ exchanger activity. Because some patients with congenital sodium diarrhea improve with age and knowing the developmental switch from NHE8 to NHE3, NHE8 may be a candidate gene for this disorder. We sequenced NHE8 from 5 patients with this disorder and found no disease‐causing homozygous mutations. Although brush border membrane Na+/H+ exchange activity may be decreased, exonic mutations in NHE8 cannot account for this disorder in these subjects.
Thymosin β4 knockdown disrupts mitochondrial functions of SW480 human colon cancer cells
Authors: Tang Mei‐Chuan , Su Yeu
Published: June 2011

Thymosin β4 (Tβ4), overexpressed in various tumors, has been shown to be involved in cellular anti‐oxidation. Reactive oxygen species (ROS) function as signaling molecules and play certain roles in tumor progression. To assess the anti‐oxidative role of endogenous Tβ4 in tumor cells, its expression in SW480 cells was knocked down by a shRNA, which induced significant increases of ROS. Interestingly, some cristae‐lost and several electron‐dense mitochondria appeared in cells with Tβ4 knockdown that was accompanied by a marked decline of the membrane potential of these organelles. Strikingly, while the ATP and lactate levels in SW480 cells were notably elevated by Tβ4 downregulation, this treatment significantly diminished the mitochondrial DNA copy number and protein levels of several subunits of the electron transport complexes. Finally, immunofluorescent staining results suggested the presence of Tβ4 in mitochondria. To the best of our knowledge, this is the first report to demonstrate that Tβ4 knockdown can disrupt the morphology and some crucial functions of mitochondria in human colorectal carcinoma (CRC) cells. (Cancer Sci 2011; 102: 1665–1672)
Human platelet antigen allele frequencies and new mutations on platelet glycoprotein genes in the Chinese Han population
Authors: Xu X. , Liu Y. , Ying Y. , Tao S. , Hong X. , Zhu F. , Lv H. , Yan L.
Published: June 2011

Background and Objectives: The frequencies of human platelet antigens (HPAs) vary between different populations. In this study, we determined the HPA allele frequencies in the Chinese Han population and identified situation of incompatibility possibly leading to alloimmunisation.

Methods: A total of 750 volunteer blood donors of the Chinese Han population were genotyped for HPA‐1 to ‐17w systems. HPA genotyping was determined by polymerase chain reaction sequence‐based typing.

Results: Among the 17 HPA systems, the allele frequency is different from other populations. We noted the absence of HPA‐7bw to HPA‐14bw, HPA‐16bw and HPA‐17bw alleles in the population. The estimated incompatibility probabilities regarding platelet antigens 1 to 6w and 15 systems after transfusion of random donor platelet were from 0·004 to 0·373. Thirteen glycoprotein alleles were observed in the population. In addition, we identified 16 novel mutations on the glycoprotein genes separated from HPA polymorphisms, including GP1BA (517‐525delAAC), ITGA2B (2722C>T and IVS26+85T>C), ITGA2 (1521C>T, 2474T>G and IVS20+10 G>C), ITGB3 (1476G>A, IVS10+19C>A, 1813G>A, IVS11+21G>A, IVS11+152A>G and IVS11‐104T>C), GP1BB (IVS1‐79G>A, IVS1‐27C>T and 129G>A) and CD109 (2139A>G). Five of them could lead to amino acid deletion, substitution or premature stop codon in corresponding glycoprotein.

Conclusions: There was a high degree of polymorphism of the membrane glycoprotein genes related to human platelet alloantigen‐1 to ‐17w systems in the Chinese Han population. These data could have some impact on the diagnosis, prevention and treatment of alloimmune thrombocytopenia.
Gonads of males and females of the mangrove tree crab Aratus pisonii (Grapsidae: Brachyura: Decapoda): a histological and histochemical view
Authors: Nicolau Cristiane F. , Nascimento Aparecida A. , Machado‐Santos Clarice , Sales Armando , Oshiro Lidia M.Y.
Published: June 2011

Nicolau, C.F., Nascimento, A.A., Machado‐Santos, C., Sales, A. and Oshiro, L.M.Y. 2011. Gonads of males and females of the mangrove tree crab Aratus pisonii (Grapsidae: Brachyura: Decapoda): a histological and histochemical view. —Acta Zoologica (Stockholm) 00:1–9.

This study describes the microscopic anatomy of the male and female gonads and the spermatogenesis and oogenesis of the mangrove tree crab Aratus pisonii. Males and females were captured in a mangrove marsh in Guaratiba (23°04′S, 44°10′W), Rio de Janeiro State, Brazil. The testes are composed of spermatogonia I (7.82 ± 0.84 μm), spermatogonia II (6.12 ± 0.72 μm), spermatocytes I (5.62 ± 0.71 μm), spermatocytes II (5.00 ± 0.42 μm), spermatids (4.01 ± 0.33 μm), and spermatozoa (2.58 ± 0.18 μm). The spermatozoids are sent to the vas deferens, which is divided into three regions: anterior vas deferens, middle vas deferens and posterior vas deferens. There are no indications of development as the production of male gametes was continuous throughout the study period. In the females, there are four ovary development stages: previtellogenesis, early‐stage vitellogenesis, mature vitellogenesis, and postspawning. Five types of cells were found in the gonads: oogonia (5.23 ± 1.31 μm), oocytes in early development (19.84 ± 5.16 μm), previtellogenic oocytes (49.49 ± 6.87 μm), vitellogenic oocytes (87.51 ± 10.23 μm), and mature oocytes (174.78 ± 29.46 μm). The findings of this study indicate that A. pisonii females lay eggs on multiple occasions throughout the study period.
Differences in the implications of maternal lipids on fetal metabolism and growth between gestational diabetes mellitus and control pregnancies
Authors: Schaefer‐Graf U. M. , Meitzner K. , Ortega‐Senovilla H. , Graf K. , Vetter K. , Abou‐Dakn M. , Herrera E.
Published: June 2011

Diabet. Med. 28, 1053–1059 (2011)

Aims  To evaluate the potential contribution of maternal glucose and lipids to fetal metabolic variables and growth in pregnancies with normal glucose tolerance in comparison with pregnancies with well‐controlled gestational diabetes previously reported by us.

Methods  In 190 pregnancies with normal oral glucose tolerance tests (controls), insulin, glucose and lipid components were determined in maternal and arterial cord blood serum. Birthweight and neonatal fat mass were obtained after delivery. Values were adjusted for maternal pre‐pregnancy BMI, Caesarean section and gestational age. Measurements were compared with those of gestational diabetes previously reported.

Results  Maternal serum glucose, triacylglycerol, free fatty acid and cholesterol levels did not differ between control pregnancies and those with gestational diabetes, whereas insulin, homeostasis model assessment and glycerol values were significantly lower in the former (2.6 vs. 5.6 μmol/l and 176 vs. 193 μmol/l, respectively). In contrast, cord blood glucose and free fatty acids were significantly lower in control pregnancies than in those with gestational diabetes (3.9 vs. 4.4 mmol/l and 80.7 vs. 137 μmol/l, respectively); the same was valid for insulin (0.03 vs. 0.05 nmol/l) and homeostasis model assessment (1.0 vs. 1.87). In control pregnancies, maternal serum glucose, free fatty acids and glycerol correlated with those in cord blood, but not with neonatal weight and fat mass, as seen for free fatty acids in those with gestational diabetes. The negative correlation between cord blood triacylglycerols and neonatal weight or fat mass previously reported in gestational diabetes could not be confirmed in control pregnancies, where all fetal lipids showed a positive correlation to neonatal anthropometrics.

Conclusion  In normal pregnancies, in contrast to those with gestational diabetes, maternal lipids do not influence neonatal weight. Similar levels of maternal lipids in pregnancies with gestational diabetes and control pregnancies, but higher free fatty acids in the cord blood of those with gestational diabetes, indicate their enhanced placental transport and/or enhanced lipolysis as a result of decreased fetal insulin responsiveness.
Why Bother Lying When You Know So Few Care? Party Contact, Education and Over‐reporting Voter Turnout in Different Types of Elections
Authors: Górecki Maciej A.
Published: June 2011

Studies on individual‐level voter turnout in the European Parliament elections rely solely on self‐reported turnout data. At the same time, a long tradition in public opinion research examines the impact of individual and contextual variables on over‐reporting of voter turnout. The ultimate goal of these efforts is an assessment of the bias introduced when turnout models are estimated from self‐reported turnout data. In this article, it is proposed that certain characteristics related to turnout (and turnout over‐reporting), like university education or party contact, should also be positively associated with political awareness and knowledge. If so, they might contribute to respondents' greater ability to distinguish between different salience levels, significantly increasing non‐voters' propensity to over‐report turnout in high‐salience elections, but not in low‐salience ones. This hypothesis is tested using data on electoral participation in Sweden, comparing patterns of turnout over‐reporting in the (high‐salience) national parliament elections and the (low‐salience) European Parliament elections. The results of this test, the first one to give an account of patterns of over‐reporting of turnout in the European Parliament elections, largely support the above hypothesis. Finally, the consequences of this phenomenon for the validity of inferences made from self‐reported turnout data are analyzed.
SUCCESSFUL MIXING? EFFECTS OF URBAN RESTRUCTURING POLICIES IN DUTCH NEIGHBOURHOODS
Authors: BOLT GIDEON , VAN KEMPEN RONALD
Published: June 2011

Concentrations of poverty in urban neighbourhoods are generally unwanted, because of all kinds of presumed negative consequences for the social mobility and the quality of life of the residents. Because of these negative associations, policies in Western European countries are often aimed at breaking up these poverty concentrations by mixing the population composition through changing the housing stock. However, whether these policies are successful remains to be seen. We asked residents of urban restructuring areas in six Dutch cities about the consequences of mixing policies. The number of residents who perceive improvements in the neighbourhood in the past few years is substantially outnumbered by the residents who report a decline in neighbourhood quality. However, many residents have high hopes for their neighbourhood's future. This finding indicates that social mixing policies have not matched the policy‐makers' expectations yet – but may do so in the course of time.
Regulation Fair Disclosure's Effect on the Information Content of Bond Rating Changes
Authors: Poon Winnie P. H. , Evans Dorla A.
Published: June 2011

The SEC implemented Regulation Fair Disclosure (Reg FD) in 2000. Reg FD requires firms to release material information to everyone simultaneously, thereby reducing information asymmetry between favoured stock analysts and others. Bond rating agencies were exempt from Reg FD in order to continue receiving the private firm information necessary for accurate credit default assessments. The exemption, if valuable to the bond market, should have resulted in an increase in the relative importance of bond rating changes on bond yield premia when Reg FD was implemented. In the first empirical study on the impact of Reg FD on the bond markets, we explore this hypothesis by measuring bond yield premia reactions to bond rating changes around the implementation of Reg FD.

For downgrades, we find the impact of Reg FD is related to firm size. The smallest firms experienced a significantly weaker bond yield premia response. The evidence for the relevance of Reg FD for upgrades is weak. Contrary to concerns from the Bond Market Association, it appears Reg FD lessened the impact of downgrades on the smallest firms, and did not affect speculative‐grade bonds or bonds with higher debt levels.
Georeferencing performance of THEOS satellite imagery
Authors: Liu Shijie , Fraser Clive S. , Zhang Chunsun , Ravanbakhsh Mehdi , Tong Xiaohua
Published: June 2011

This paper reports on the application of a generic physical sensor orientation model for evaluation of the georeferencing performance of 2 m resolution imagery from the Thailand Earth Observation System (THEOS) satellite. Within the generic sensor orientation model, orbit and attitude data are employed to describe the satellite trajectory, which is further modelled by splines. The satellite orbit and sensor attitude errors are then compensated via sensor orientation adjustment using a modest number of ground control points (GCPs), resulting in improved georeferencing. The generic sensor model and the integration of the THEOS orientation parameters into the model are first described. The presence of errors in the satellite line‐of‐sight data, which result in imprecise sensor interior orientation are then discussed. Such errors can be effectively accounted for through modelling via a cubic polynomial, leading to sub‐pixel georeferencing accuracy. An account is then given of an experimental evaluation of THEOS georeferencing conducted in a well‐established testfield near Melbourne, Australia. The results demonstrate that sub‐pixel 2D geopositioning accuracy is readily achievable with single THEOS images and within strips of up to three images, with as few as six GCPs to effect an orbit adjustment. However, accuracy decreases to near the 2‐pixel level over a strip length of five images.
Photogrammetric processing of low‐altitude images acquired by unpiloted aerial vehicles
Authors: Zhang Yongjun , Xiong Jinxin , Hao Lijuan
Published: June 2011

Low‐altitude images acquired by unpiloted aerial vehicles have the advantages of high overlap, multiple viewing angles and very high ground resolution. These kinds of images can be used in various applications that need high accuracy or fine texture. A novel approach is proposed for parallel processing of low‐altitude images acquired by unpiloted aerial vehicles, which can automatically fly according to predefined flight routes under the control of an autopilot system. The general overlap and relative rotation angles between two adjacent images are estimated by overall matching with an improved scale‐invariant feature transform (SIFT) operator. Precise conjugate points and relative orientation parameters are determined by a pyramid‐based least squares image matching strategy and the relative orientation process. Bundle adjustment is performed with automatically matched conjugate points and interactively measured ground control points. After this aerial triangulation process the high‐resolution images can be used to advantage in obtaining precise spatial information products such as digital surface models, digital orthophotomaps and 3D city models. A parallel processing strategy is introduced in this paper to improve the computational time of the photogrammetric process. Experimental results show that the proposed approaches are effective for processing low‐altitude images, and have high potential for the acquisition of spatial information at large mapping scales, with rapid response and precise modelling in three dimensions.
Causality, Criticality, and Reading Words: Distinct Sources of Fractal Scaling in Behavioral Sequences
Authors: Moscoso del Prado Martín Fermín
Published: June 2011

The finding of fractal scaling (FS) in behavioral sequences has raised a debate on whether FS is a pervasive property of the cognitive system or is the result of specific processes. Inferences about the origins of properties in time sequences are causal. That is, as opposed to correlational inferences reflecting instantaneous symmetrical relations, causal inferences concern asymmetric relations lagged in time. Here, I integrate Granger‐causality with inferences about FS. Four simulations illustrate that causal analyses can isolate distinct FS sources, whereas correlational techniques cannot. I then analyze three simultaneous sequences of responses from a database of word‐naming trials. I find that two, or perhaps three, distinct sources account for the presence of FS in these sequences, but FS is not a general property of the system. This suggests that FS arises due to the properties of a limited number of identifiable psychological and/or neural processes. Finally, I reanalyze a previously published dataset of acoustic frequency spectra using the new tools. The causality/criticality combination introduced here offers a new important perspective in the study of cognition.
Regulation of Vps4 During MVB Sorting and Cytokinesis
Authors: Babst Markus , Davies Brian A. , Katzmann David J.
Published: June 2011

Multivesicular body (MVB) formation is the result of invagination and budding of the endosomal limiting membrane into its intralumenal space. These intralumenal vesicles (ILVs) contain a subset of endosomal transmembrane cargoes destined for degradation within the lysosome, the result of active selection during MVB sorting. Membrane bending and scission during ILV formation is topologically similar to cytokinesis in that both events require the abscission of a membrane neck that is oriented away from the cytoplasm. The endosomal sorting complexes required for transport (ESCRTs) represent cellular machinery whose function makes essential contributions to both of these processes. In particular, the AAA‐ATPase Vps4 and its substrate ESCRT‐III are key components that seem to execute the membrane abscission reaction. This review summarizes current knowledge about the Vps4‐ESCRT‐III system and discusses a model for how the recruitment of Vps4 to the different sites of function might be regulated.

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Plasmodium falciparum Apicoplast Transit Peptides are Unstructured in vitro and During Apicoplast Import
Authors: Gallagher John R. , Matthews Krista A. , Prigge Sean T.
Published: June 2011

Trafficking of soluble proteins to the apicoplast in Plasmodium falciparum is determined by an N‐terminal transit peptide (TP) which is necessary and sufficient for apicoplast import. Apicoplast precursor proteins are synthesized at the rough endoplasmic reticulum, but are then specifically sorted from other proteins in the secretory pathway. The mechanism of TP recognition is presently unknown. Apicoplast TPs do not contain a conserved sequence motif; therefore, we asked whether they contain an essential structural motif. Using nuclear magnetic resonance to study a model TP from acyl carrier protein, we found a short, low‐occupancy helix, but the TP was otherwise disordered. Using an in vivo localization assay, we blocked TP secondary structure by proline mutagenesis, but found robust apicoplast localization. Alternatively, we increased the helical content of the TP through mutation while maintaining established TP characteristics. Apicoplast import was disrupted in a helical mutant TP, but import was then restored by the further addition of a single proline. We conclude that structure in the TP interferes with apicoplast import, and therefore TPs are functionally disordered. These results provide an explanation for the amino acid bias observed in apicoplast TPs.
BRICHOS domain associated with lung fibrosis, dementia and cancer – a chaperone that prevents amyloid fibril formation?
Authors: Willander Hanna , Hermansson Erik , Johansson Jan , Presto Jenny
Published: June 2011

The BRICHOS domain was initially defined from sequence alignments of the Bri protein associated with familial dementia, chondromodulin associated with chondrosarcoma and surfactant protein C precursor (proSP‐C) associated with respiratory distress syndrome and interstitial lung disease (ILD). Today BRICHOS has been found in 12 protein families. Mutations in the Bri2 and proSP‐C genes result in familial dementia and ILD, respectively, and both these conditions are associated with amyloid formation. Amyloid is of great medical relevance as it is found in several major incurable diseases, like Alzheimer’s and Parkinson’s disease and diabetes mellitus. Work on recombinant BRICHOS domains and transfected cells indicate that BRICHOS is a chaperone domain that, during biosynthesis, binds to precursor protein regions with high β‐sheet propensities, thereby preventing them from amyloid formation. Regions prone to form β‐sheets are present in all BRICHOS‐containing precursor proteins and are probably eventually released by proteolytic cleavage, generating different peptides with largely unknown bioactivities. Recombinant BRICHOS domains from Bri2 and proSP‐C have been found to efficiently prevent SP‐C, the amyloid β‐peptide associated with Alzheimer’s disease, and medin, found in aortic amyloid, from forming amyloid fibrils. The data collected so far on BRICHOS raise several interesting topics for further research: (a) amyloid formation is a potential threat for many more proteins than the ones recognized so far in amyloid diseases; (b) amyloid formation of widely different peptides involves intermediate(s) that are recognized by the BRICHOS domain, suggesting that they have distinct structural similarities; and (c) the BRICHOS domain might be harnessed in therapeutic strategies against amyloid diseases.
Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia
Authors: YAO Hong , LUO Yi‐Bo
Published: June 2011

Abstract  Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral traits. The plasticity of floral longevity to pollination may be an adaptation of plants to pollen limitation. However, this adaptation is less critical in short‐lived flowers. To evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia, a gynodioecious herb with short‐lived flowers, we analyzed its breeding system, tested sex‐differential pollen limitation, and compared variations in floral display size in natural populations in Duolun County, Inner Mongolia, China. Hand pollination experiments and pollinator exclusion treatments revealed that P. tanacetifolia is self‐compatible and non‐autonomously apomictic and shows sex‐differential pollen limitation. The plasticity of floral longevity to pollination was observed; the floral duration of female plants was prolonged by approximately 3–4 hours with pollination exclusion treatment. Moreover, the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural pollination. Under natural pollination conditions, the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite plants. Furthermore, approximately 50% of the pollen grains spread out of the anthers of hermaphrodite flowers within 2 h of anthesis; the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their petals. These results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious P. tanacetifolia.