bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood Pressure and Brain Injury in Older Adults: Findings from a Community‐Based Autopsy Study
Authors: Wang Lucy Y. , Larson Eric B. , Sonnen Joshua A. , Shofer Jane B. , McCormick Wayne , Bowen James D. , Montine Thomas J. , Li Ge
Published: September 2009

OBJECTIVES: To examine correlations between blood pressure (BP) and dementia‐related pathological brain changes in a community‐based autopsy sample.

DESIGN: Prospective cohort study.

SETTING: A large health maintenance organization in Seattle, Washington.

PARTICIPANTS: A cohort of 250 participants aged 65 and older and cognitively normal at time of enrollment in the Adult Changes in Thought (ACT) Study and who underwent autopsy.

MEASUREMENTS: BP and history of antihypertensive treatment were taken at enrollment. A linear regression model was used to examine the relationship between BP (systolic (SBP) and diastolic (DBP)) at enrollment and pathological changes in the cerebrum (cystic macroscopic infarcts, microinfarcts, neuritic plaques, neurofibrillary tangles, and cortical Lewy bodies).

RESULTS: The presence of more than 2 microinfarcts, but not any other pathological change, was independently associated with SBP in younger participants (65–80, n=137) but not in older participants (>80, n=91). The relative risk (RR) for more than two microinfarcts with each 10‐mmHg increase in SBP was 1.15 (95% confidence interval (CI)=1.00–1.33) in the younger participants, adjusted for age at entry, sex, and time to death. This RR was particularly strong in younger participants not taking antihypertensive medications (RR=1.48, 95% CI=1.21, 1.81); significant associations were not observed in participants treated for hypertension. Findings for DBP were negative.

CONCLUSION: The association between high SBP and cerebrovascular damage in untreated older adults (65–80) suggests that adequate hypertension treatment may reduce dementia risk by minimizing microvascular injury to cerebrum.
The Vulnerable Elders‐13 Survey Predicts 5‐Year Functional Decline and Mortality Outcomes in Older Ambulatory Care Patients
Authors: Min Lillian , Yoon William , Mariano Jeff , Wenger Neil S. , Elliott Marc N. , Kamberg Caren , Saliba Debra
Published: September 2009

OBJECTIVES: To test the predictive properties of the Vulnerable Elders‐13 Survey (VES‐13) a short tool that predicts functional decline and mortality over a 1‐ to 2‐year follow‐up interval over a 5‐year interval.

DESIGN: Longitudinal evaluation with mean follow‐up of 4.5 years.

SETTING: Two managed‐care organizations.

PARTICIPANTS: Six hundred forty‐nine community‐dwelling older adults (≥75) enrolled in the Assessing Care of Vulnerable Elders observational study who screened positive for symptoms of falls or fear of falling, bothersome urinary incontinence, or memory problems.

MEASUREMENTS: VES‐13 score (range 1–10, higher score indicates worse prognosis), functional decline (decline in count of 5 activities of daily living or nursing home entry), and deaths.

RESULTS: Higher VES‐13 scores were associated with greater predicted probability of death and decline in older patients over a mean observation period of 4.5 years. For each additional VES‐13 point, the odds of the combined outcome of functional decline or death was 1.37 (95% confidence interval (CI)=1.25–1.50), and the area under the receiver operating curve was 0.75 (95% CI=0.71–0.80). In the Cox proportional hazards model predicting time to death, the hazard ratio was 1.23 (95% CI=1.19–1.27) per additional VES‐13 point.

CONCLUSION: This study extends the utility of the VES‐13 to clinical decisions that require longer‐term prognostic estimates of functional status and survival.
The On‐Road Difficulties of Older Drivers and Their Relationship with Self‐Reported Motor Vehicle Crashes
Authors: Wood Joanne M. , Anstey Kaarin J. , Lacherez Philippe F. , Kerr Graham K. , Mallon Kerry , Lord Stephen R.
Published: September 2009

OBJECTIVES: To quantify the driving difficulties of older adults using a detailed assessment of driving performance and to link this with self‐reported retrospective and prospective crashes.

DESIGN: Prospective cohort study.

SETTING: On‐road driving assessment.

PARTICIPANTS: Two hundred sixty‐seven community‐living adults aged 70 to 88 randomly recruited through the electoral roll.

MEASUREMENTS: Performance on a standardized measure of driving performance.

RESULTS: Lane positioning, approach, and blind spot monitoring were the most common error types, and errors occurred most frequently in situations involving merging and maneuvering. Drivers reporting more retrospective or prospective crashes made significantly more driving errors. Driver instructor interventions during self‐navigation (where the instructor had to brake or take control of the steering to avoid an accident) were significantly associated with higher retrospective and prospective crashes; every instructor intervention almost doubled prospective crash risk.

CONCLUSION: These findings suggest that on‐road driving assessment provides useful information on older driver difficulties, with the self‐directed component providing the most valuable information.
1. The Role of Land Markets in Economic Crises
Authors: Gaffney Mason
Published: September 2009

Abstract

It is widely recognized that the economic crisis of 2009 was caused by unsound lending for real estate. Largely ignored, however, is that this contraction was easily predicted on the basis of a well‐established pattern of land speculation, premature subdivision, and excessive building on marginal land that recurs approximately once every 18 years. Capital locked up in projects that are started during a land bubble is effectively lost during the downturn, leaving the nation without sufficient capital to finance ordinary business operations during the recovery period. The best instrument for avoiding this boom‐bust cycle is the property tax and, more specifically, the portion that falls on land. We explore here the ways in which the property tax influences the intensity, timing, and location of development. We also examine why frequent and accurate assessment are essential to make the property tax an effective method of preventing speculative real estate bubbles.
Why Do U.S. Firms Hold So Much More Cash than They Used To?
Authors: BATES THOMAS W. , KAHLE KATHLEEN M. , STULZ RENÉ M.
Published: September 2009

The average cash‐to‐assets ratio for U.S. industrial firms more than doubles from 1980 to 2006. A measure of the economic importance of this increase is that at the end of the sample period, the average firm can retire all debt obligations with its cash holdings. Cash ratios increase because firms' cash flows become riskier. In addition, firms change: They hold fewer inventories and receivables and are increasingly R&D intensive. While the precautionary motive for cash holdings plays an important role in explaining the increase in cash ratios, we find no consistent evidence that agency conflicts contribute to the increase.
Credit Contagion from Counterparty Risk
Authors: JORION PHILIPPE , ZHANG GAIYAN
Published: September 2009

Standard credit risk models cannot explain the observed clustering of default, sometimes described as “credit contagion.” This paper provides the first empirical analysis of credit contagion via direct counterparty effects. We find that bankruptcy announcements cause negative abnormal equity returns and increases in CDS spreads for creditors. In addition, creditors with large exposures are more likely to suffer from financial distress later. This suggests that counterparty risk is a potential additional channel of credit contagion. Indeed, the fear of counterparty defaults among financial institutions explains the sudden worsening of the credit crisis after the Lehman bankruptcy in September 2008.
The Relation between Price and Performance in the Mutual Fund Industry
Authors: GIL‐BAZO JAVIER , RUIZ‐VERDÚ PABLO
Published: September 2009

Gruber (1996)drew attention to the puzzle that investors buy actively managed equity mutual funds, even though on average such funds underperform index funds. We uncover another puzzling fact about the market for equity mutual funds: Funds with worse before‐fee performance charge higher fees. This negative relation between fees and performance is robust and can be explained as the outcome of strategic fee‐setting by mutual funds in the presence of investors with different degrees of sensitivity to performance. We also find some evidence that better fund governance may bring fees more in line with performance.
Business Networks, Corporate Governance, and Contracting in the Mutual Fund Industry
Authors: KUHNEN CAMELIA M.
Published: September 2009

Business connections can mitigate agency conflicts by facilitating efficient information transfers, but can also be channels for inefficient favoritism. I analyze these two effects in the mutual fund industry and find that fund directors and advisory firms that manage the funds hire each other preferentially based on the intensity of their past interactions. I do not find evidence that stronger board‐advisor ties correspond to better or worse outcomes for fund shareholders. These results suggest that the two effects of board‐management connections on investor welfare—improved monitoring and increased potential for collusion—balance out in this setting.
Driven to Distraction: Extraneous Events and Underreaction to Earnings News
Authors: HIRSHLEIFER DAVID , LIM SONYA SEONGYEON , TEOH SIEW HONG
Published: September 2009

Recent studies propose that limited investor attention causes market underreactions. This paper directly tests this explanation by measuring the information load faced by investors. The investor distraction hypothesis holds that extraneous news inhibits market reactions to relevant news. We find that the immediate price and volume reaction to a firm's earnings surprise is much weaker, and post‐announcement drift much stronger, when a greater number of same‐day earnings announcements are made by other firms. We evaluate the economic importance of distraction effects through a trading strategy, which yields substantial alphas. Industry‐unrelated news and large earnings surprises have a stronger distracting effect.
Getting Out Early: An Analysis of Market Making Activity at the Recommending Analyst's Firm
Authors: JUERGENS JENNIFER L. , LINDSEY LAURA
Published: September 2009

This paper examines trading volume for Nasdaq market makers around analyst recommendation changes issued by an analyst at the same firm. Using Nasdaq PostData, we find a disproportionate increase in market making volume associated with the firm's recommendation changes and evidence of elevated sell volume at the recommending analyst's firm in the 2 days preceding a downgrade. The implications are that the information source matters in determining the placement of trades and that the issuing analyst's firm appears to be rewarded for prereleasing information through increased volume. These findings constitute new evidence of compensation for research production through the market making channel.
Making Sense of Cents: An Examination of Firms That Marginally Miss or Beat Analyst Forecasts
Authors: BHOJRAJ SANJEEV , HRIBAR PAUL , PICCONI MARC , McINNIS JOHN
Published: September 2009

This paper examines the performance consequences of cutting discretionary expenditures and managing accruals to exceed analyst forecasts. We show that firms that just beat analyst forecasts with low quality earnings exhibit a short‐term stock price benefit relative to firms that miss forecasts with high quality earnings. This trend, however, reverses over a 3‐year horizon. Additionally, firms reducing discretionary expenditures to beat forecasts have significantly greater equity issuances and insider selling in the following year, consistent with managers understanding the myopic nature of their actions. Our results confirm survey evidence suggesting managers engage in myopic behavior to beat benchmarks.
Outcomes in Patients Requiring Cardioversion Following Catheter Ablation of Atrial Fibrillation
Authors: CHILUKURI KARUNA , DUKES JONATHAN , DALAL DARSHAN , MARINE JOSEPH E. , HENRIKSON CHARLES A. , SCHERR DANIEL , SINHA SUNIL , BERGER RONALD , CHENG ALAN , NAZARIAN SAMAN , SPRAGG DAVID , CALKINS HUGH
Published: September 2009

Outcomes of Cardioversion Post AF Ablation. Introduction: Early recurrence of atrial tachyarrhythmias is commonly noted after catheter ablation of atrial fibrillation (AF). The long‐term outcomes of patients who require cardioversion for persistent AF after AF ablation is not known. This study reports the outcomes of patients who underwent cardioversion for persistent AF or atrial flutter following an AF ablation procedure.

Methods:
The patient population comprised 55 patients (mean age 58 ± 10 years, 35% paroxysmal) who underwent catheter ablation of AF and subsequently required electrical cardioversion for persistent AF (45 patients) or atrial flutter (10 patients). Cardioversion was defined as early (within 90 days of the ablation procedure) or late (between 90 and 180 days following ablation).

Results:
The mean follow‐up duration was 15 ± 8 months. Forty‐six of the 55 patients (84%) patients experienced recurrence during follow‐up. The average time to recurrence after cardioversion was 37 days. Of the 55 patients, 8 (15%) patients had a complete success, 11 (20%) patients had a partial success and 36 patients (65%) had a failed outcome. Seven of the 43 patients (16%) who underwent early cardioversion had a complete success as opposed to one of 12 patients (8%) who underwent late cardioversion (P = 0.49).

Conclusions:
This study shows that >80% of patients who undergo cardioversion for persistent AF or atrial flutter after AF ablation have recurrence. The timing of cardioversion did not affect the outcome. These findings allow clinicians to provide realistic expectations to patients regarding the long‐term outcome and/or requirement for a second ablation procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 27–32, January 2010)
Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation
Authors: YAMADA TAKUMI , DOPPALAPUDI HARISH , McELDERRY HUGH T. , OKADA TARO , MURAKAMI YOSHIMASA , INDEN YASUYA , YOSHIDA YUKIHIKO , KANEKO SHINJI , YOSHIDA NAOKI , MUROHARA TOYOAKI , EPSTEIN ANDREW E. , PLUMB VANCE J. , KAY G. NEAL
Published: September 2009

Idiopathic VAs Originating from the LV Papillary Muscles. Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.

Methods and Results:
We studied 71 patients with VAs originating from the LV anterolateral and posteroseptal regions among 159 patients undergoing successful catheter ablation of idiopathic LV VAs. PAM VAs were uncommon, rare in a sustained form, and more common from the posterior papillary muscle (PPM) than anterior papillary muscle (APM). A younger age was a good predictor for differentiating left posterior fascicular VAs from PPM VAs. There were several electrocardiographic features that accurately differentiated PAM and LV fascicular VAs from mitral annular VAs. However, an R/S ratio ≤1 in lead V6 in the LV anterolateral region and a QRS duration >160 ms in the LV posteroseptal region were the only reliable predictors for differentiating PAM VAs from LV fascicular VAs. A sharp ventricular prepotential was recorded at the successful ablation site during 42% of the PAM VAs. Radiofrequency current with an irrigated or conventional 8‐mm tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins whereas that with a nonirrigated 4‐mm tip ablation catheter produced excellent results in LV fascicular and mitral annular VAs.

Conclusions:
There are differences in the electrocardiographic and electrophysiological features among VAs originating from these regions that are helpful for their diagnosis and effective catheter ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 62–69, January 2010)
Neurally Mediated Syncope as a Cause of Syncope in Patients with Brugada Electrocardiogram
Authors: YOKOKAWA MIKI , OKAMURA HIDEO , NODA TAKASHI , SATOMI KAZUHIRO , SUYAMA KAZUHIRO , KURITA TAKASHI , AIHARA NAOHIKO , KAMAKURA SHIRO , SHIMIZU WATARU
Published: September 2009

Neurally Mediated Syncope in Brugada Syndrome.

Introduction:
Patients with type 1 Brugada electrocardiogram (ECG) and an episode of syncope are diagnosed as symptomatic Brugada syndrome; however, all episodes of syncope may not be due to ventricular tachyarrhythmia.

Methods and Results:
Forty‐six patients with type 1 Brugada ECG (all males, 51 ± 13 years, 29 spontaneous, 17 Ic‐drug induced), 20 healthy control subjects (all males, 35 ± 11 years), and 15 patients with suspected neurally mediated syncope (NMS; 9 males, 54 ± 22 years) underwent the head‐up tilt (HUT) test. During the HUT test, 12‐lead ECGs were recorded in all patients, and the heart rate variability was investigated in some patients. Sixteen (35%) of 46 patients with Brugada ECG, 2 (10%) of 20 control subjects, and 10 (67%) of 15 patients with suspected NMS showed positive responses to the HUT test. Although no significant differences were observed in HUT‐positive rate among Brugada patients with documented VT (7/14; 50%), syncope (5/19; 26%) and asymptomatic patients (4/13; 31%), the HUT‐positive rate was significantly higher in patients with documented VT (50%) and those with VT or no symptoms (11/27, 41%) compared to that in control subjects (10%) (P < 0.05). Augmentation of ST‐segment amplitude (≥0.05 mV) in leads V1‐V3 was observed in 11 (69%) of 16 HUT‐positive patients with Brugada ECG during vasovagal responses, and was associated with augmentation of parasympathetic tone following sympathetic withdrawal.

Conclusion:
Thirty‐five percent of patients with Brugada ECG showed vasovagal responses during the HUT test, suggesting that some Brugada patients have impaired balance of autonomic nervous system, which may relate to their syncopal episodes. (J Cardiovasc Electrophysiol, Vol. 21, pp. 186‐192, February 2010)
Uninterrupted Warfarin for Periprocedural Anticoagulation in Catheter Ablation of Typical Atrial Flutter: A Safe and Cost‐Effective Strategy
Authors: FINLAY MALCOLM , SAWHNEY VINIT , SCHILLING RICHARD , THOMAS GLYN , DUNCAN EDWARD , HUNTER ROSS , VIRDI GURPREET , ABRAMS DOMINIC , SPORTON SIMON , DHINOJA MEHUL , EARLEY MARK
Published: September 2009

Uninterrupted Warfarin for Periprocedural Anticoagulation in Catheter Ablation of Typical Atrial Flutter.
Introduction: Many patients undergoing catheter ablation of atrial flutter (AFL) require periprocedural anticoagulation. We compared a strategy of conversion to low molecular weight heparin (LMWH) periprocedure to uninterrupted warfarinization in a nonrandomized, case‐controlled study.

Methods: One hundred and one consecutive patients requiring periprocedural anticoagulation for catheter ablation of typical AFL were studied. The first 51 patients underwent conversion to LMWH (enoxaparin 1 mg/kg bd) with a warfarin pause (LMWH group), the subsequent 50 continued with uninterrupted oral anticoagulation (Warfarin group). Primary endpoint was a composite of major and minor bleeding complications and groin symptoms.

Results: Fewer patients in the Warfarin group reached the primary endpoint (36.0% vs 56.8%, P = 0.013). Four patients in the LMWH group but no patient in the Warfarin group required hospital admission for bleeding‐related complications. Cost analysis showed mean cost per patient of anticoagulation with LMWH to be £100.9 (95% CI 94.46–107.30) compared to £10.23 (4.49–15.97) in the Warfarin group (P < 0.0001). Transesophageal echocardiography (TEE) was performed prior to ablation in 11 patients in the Warfarin group and in 3 patients in the LMWH (P = 0.019). When TEE costs were included, costs were £125.00 ($188.25) (96.80–153.60) for the LMWH strategy and £108.5 ($163.40) (54.92–162.1) for the Warfarin group (P < 0.0001).

Conclusions: Catheter ablation of typical AFL without interruption of warfarin appears safer and more cost‐effective than periprocedural conversion to LMWH. It could be used as a routine anticoagulation strategy for the ablation of right‐sided arrhythmias. (J Cardiovasc Electrophysiol, Vol. 21, pp. 150‐154, February 2010)
Where does all the talent flow? Migration of young graduates and nongraduates, Canada 1996–2001
Authors: DELISLE FRANÇOISE , SHEARMUR RICHARD
Published: September 2009

It has recently been suggested that cities and regions should focus upon attracting talented individuals as a means to develop. Such a suggestion implies two things: first that it is possible to meaningfully alter migration flows by way of local policy, and second that these flows have an effect on local growth (and not the reverse as has generally been admitted). In this paper, we begin to investigate the empirical foundations of such assertions by examining some structural determinants of graduate migration flows by comparing them, in a gravity model context, to flows of nongraduates. Our contention is that, if migration flows are structured by such factors, then policies aimed at modifying flows—and any research purporting to give such policy advice—must first take them into account. We show that migration flows are strongly dependent on basic gravity variables such as size and distance, but that these and other variables (such as income differences, presence of graduates and border effects) do not affect all flows equally. Furthermore, we show that certain factors that are assumed to be local (such as wage levels) in fact only operate at a provincial level. Thus policies implemented locally may have little or no effect if they are manipulating factors that operate at a different scale.
The changing biosphere: recent insights from paleoenvironmental science into drivers, mechanisms and impacts
Authors: FINKELSTEIN SARAH A.
Published: September 2009

Paleoenvironmental science has experienced a recent surge in interest and activity as concerns grow over global environmental change. Key research questions in the biotic realm of paleoenvironmental science focus on explaining climatic change at time scales of decades to centuries and understanding ecosystem responses to these changes. Biotic responses are increasingly being studied at smaller spatial scales to identify local factors that determine the sensitivity of a particular system to climatic change. These findings can then be applied to solving a variety of problems, such as setting conservation targets or testing mechanisms for observed climatic and biogeographic phenomena. Research approaches commonly used today include hypothesis testing, which has now become more sophisticated as paleoecologists and paleoclimatologists integrate with modellers. Other frameworks involve the quantitative integration of multiple proxy indicators and the use of extensive publicly available data networks to produce new datasets for paleoclimatic reconstructions and other applications.
Mapping international flows of electronic waste
Authors: LEPAWSKY JOSH , MCNABB CHRIS
Published: September 2009

In this paper, we map the international trade in electronic waste (e‐waste). We quantify the directions and magnitude of this trade at the global scale and examine the utility of the pollution haven hypothesis for explaining the observed trade patterns. Our results demonstrate four key findings: the international trade in e‐waste is a more complex story than being one about ‘rich’ countries dumping waste in ‘poor’ countries; the trade in e‐waste is highly regionalized, with intra‐regional trade accounting for most of the total trade flows; the pollution haven hypothesis is an important, but partial, explanation of observed trade patterns; and there is a need to conceptualize the trade and traffic of e‐waste as open ended and contingent processes facilitated by situated practices of wasting and valuing that rely on geographic difference and mobility for the exchanges between the domains of waste and value to occur.
Electrochemical Properties of Polymer‐Derived SiCN Materials as the Anode in Lithium Ion Batteries
Authors: Su Dong , Li Ya‐Li , Feng Yan , Jin Jun
Published: September 2009

Polymer‐derived SiCN materials, pyrolyzed from polysilylethylenediamine at temperatures between 600° and 1500°C, are used as the anode in lithium batteries, and their electrochemical performance is studied. The SiCN materials, having composition ranging from organic to inorganic and phase structures from amorphous to crystalline, are obtained from pyrolysis at different temperatures. Electrochemical measurements show that the 1000°–1300°C derived SiCN materials exhibit a first‐cycle discharge capacity of 608–754 mAh/g at a current density of 40 mA/g, which is higher than that of a graphite anode. The discharge capacity reduces to 170–230 mAh/g after seven charge–discharge cycles and stays in this range over 30 cycles. Compositional and structural analyses show that the 1000°–1300°C derived SiCN materials have an amorphous phase and contain free carbon in the SiCN network. In contrast, the 600°–800°C derived SiCN, which contains organic groups, and the 1400°–1500°C derived SiCN, which contains SiC crystallites, show a much lower charge and discharge capacity compared with that of the amorphous SiCN anode. This suggests that free carbon in SiCN and the amorphous structure of the SiCN materials contribute to the electrochemical performance of the SiCN materials. It seems that the free carbon phase acts as an active site for the insertion of Li ions while the amorphous SiCN network provides a path for Li‐ion transfer. The strong dependence of the electrochemical capacities of the polymer‐derived SiCN materials on their compositions and structures suggests the potential to enhance the electrochemical performance of the materials through molecular design and/or the control of material structure.
Diffusion and Creep in Silica‐Doped Tetragonal Zirconia
Authors: Ghosh Santonu , Kilo Martin , Borchardt Günter , Chokshi Atul H.
Published: September 2009

Silica segregation at two grain junctions or in amorphous triple junction pockets can influence creep by altering the grain‐boundary diffusion coefficient. Although the addition of silica to superplastic yttria‐stabilized tetragonal zirconia enhances ductility, differences in reported creep parameters have limited critical identification of rate controlling mechanisms. The present study on a pure 3 mol% yttria‐stabilized tetragonal zirconia (3YTZ) and 3YTZ with 0.39 or 3.9 wt% silica involved a detailed characterization of creep over a wide range of experimental conditions and also tracer diffusion measurements. The data broadly show transitions in creep stress exponents from n∼1 to ∼2 to ∼3 with a decrease in the stress. The data at high stresses are consistent with Coble diffusion creep, and creep at lower stresses is attributed to interface‐controlled diffusion creep. Measurements indicated that silica does not have any significant influence on grain boundary or lattice diffusion, and this is consistent with the observation that 3YTZ and 3YTZ with 0.39% or 3.9% silica exhibit essentially identical creep behavior in the Coble creep regime. Silica influences the interface control process so that the transitions in stress exponents are pushed to lower stresses with an increase in silica content.
Broadband Near‐IR Emission in Tm/Er‐Codoped GeS2–In2S3‐Based Chalcohalide Glasses
Authors: Xu Yinsheng , Zhang Qiang , Shen Ce , Chen Danping , Zeng Huidan , Chen Guorong
Published: September 2009

The near IR emission spectra of Tm/Er‐codoped GeS2–In2S3‐based chalcohalide glasses are studied with an 808 nm laser as excitation source. A broad emission with a full‐width at half‐maximum of ∼170 nm is recorded in a 0.5Tm2S3–0.1Er2S3‐codoped 70GeS2–20In2S3–10CsBr (in mol%) glass. The luminescence mechanisms are discussed with different CsI concentration, different halogen atoms, and different In content. These results suggest that both halogen (X) atoms and [InSxX4−x] structural units can enhance the emission intensity located at 1460 nm.
Wet Processing and Low‐Temperature Pressureless Sintering of SiC Using a Novel Al3BC3Sintering Additive
Authors: Lee Sea‐Hoon , Sakka Yoshio , Tanaka Hidehiko , Kagawa Yutaka
Published: September 2009

Highly concentrated slurry preparation and low‐temperature pressureless sintering of SiC using a novel Al3BC3additive were investigated. Al+B4C+C powder mixture, which is a conventional sintering additive system of SiC, could not be dispersed in ethyl alcohol above 10 vol%. In contrast, Al3BC3slurry (average particle size: 0.5 μm) could be prepared up to 50 vol% solid loading and SiC slurry containing 10 wt% Al3BC3was successfully fabricated up to 45 vol%. The relative density of SiC was 97.9% after pressureless sintering at 1850°C. Young's modulus and hardness of a sintered SiC were 411 and 22.5 GPa, respectively. The present report proposes a method for the low‐temperature pressureless sintering of SiC specimens having complex shape and fair mechanical properties by the application of a ternary compound (Al3BC3) as a novel‐sintering additive.
White Luminescence from Sol–Gel‐Derived SiOC Thin Films
Authors: Karakuscu Aylin , Guider Romain , Pavesi Lorenzo , Sorarù Gian D.
Published: September 2009

A new approach to obtain visible luminescence from sol–gel‐derived SiOC films is proposed. In order to investigate the influence of Si and C content, Si‐ and C‐rich SiOC films were prepared as well as stoichiometric SiOC films. High intense white luminescence is obtained where the emission color can be controlled by the experimental parameters such as the starting sol–gel‐composition and the pyrolysis temperature. In stoichiometric SiOC films, low pyrolysis temperature yields UV‐blue luminescence, whereas high temperatures favor green‐yellow luminescence. On the contrary, in Si‐rich SiOC films, intense white luminescence is obtained with a broad emission from 430 to 900 nm and an external quantum efficiency (EQE) of 11.5%. Relatively, stoichiometric SiOC films showed an EQE of 5%. Finally, C‐rich SiOC films did not show noticeable luminescence due to absorption by carbon clusters.
Constrained Sintering of a Glass Ceramic Composite: II. Symmetric Laminate
Authors: Ollagnier Jean‐Baptiste , Green David J. , Guillon Olivier , Rödel Jürgen
Published: September 2009

The sintering behavior of symmetric laminates has been experimentally measured and modeled. Two cases are distinguished: (i) sintering of a viscous layer between viscous substrates and (ii) sintering of a viscous layer between elastic substrates. A simple model based on a persisting isotropic microstructure allowed computation of developing in‐plane stresses. These in conjunction with a viscous Poisson's coefficient were taken to predict out‐of‐plane stresses and finally densification rate. This approach, however, proved unsuccessful to predict the large observed differences in densification rate between laminates constrained by either green or dense alumina substrates. The discrepancy was found to be due to widely different microstructures developing with different degrees of elastic constraint. Pore area and pore and particle orientation were determined to quantify these microstructural changes.
Crystallite Size Refinement of ZrB2by High‐Energy Ball Milling
Authors: Galán Carlos A. , Ortiz Angel L. , Guiberteau Fernando , Shaw Leon L.
Published: September 2009

The high‐energy ball milling behavior of a commercially available ZrB2powder was studied by X‐ray diffractometry and transmission electron microscopy. It is shown that ball milling is very effective in obtaining nanocrystalline ZrB2powder. Further, the crystallite size refinement occurs through repeated brittle fracture, with the final crystal size being limited by a combination of the fracture strength of particles and the compressive stress induced by collision of balls. With this mechanism, the crystallite size first decreases rapidly, then gradually, and finally approaches to an asymptotic limit as the ball‐milling time increases. Additionally, the higher the ball‐to‐powder weight ratio, the faster the decrease in the crystallite size and the smaller the ultimate crystallite size.
Meso/Macroporous Ceria with Enhanced Surface Oxygen Activity via Plant‐Leaf Mineralization
Authors: Chow Sukkwun , Fan Tongxiang , Ding Jian , Zhang Di
Published: September 2009

Biomorphic cerias were produced through mineralizing plant‐leaf templates (camphor and common oleander) with a cerium nitrate precursor. They were mesoporous while inheriting the species‐dependent macrofeatures of plant‐leaf templates, like macropores, channels, and microfibrous clusters, to have a meso/macroporous hierarchy. Surface oxygen activity was enhanced for the biomorphic cerias, as was revealed by temperature‐programmed reduction measurements, suggesting their potentials in mid‐temperature (300°–600°C) applications of oxygen storage, catalysis, gas sensing, etc.
Human Rights Publishing Under Threat
Authors: Walsh‐Haney Heather
Published: September 2009

Shannon Speed is contributing editor of “Human Rights Forum,” the AAA Committee for Human Rights column in Anthropology News.
Development and use of a monoclonal antibody to detect semi‐digested proteins of the English grain aphid, Sitobion avenae, in the guts of ladybird beetle predators
Authors: Gao Shu‐jing , Zhou Xiao‐rong , Pang Bao‐ping , Van Loon Joop J.A. , Zhao Gui‐qin
Published: September 2009

A monoclonal antibody (McAb), EGA‐4A9, was developed to detect the semi‐digested proteins of the English grain aphid, Sitobion avenae (Fabricius) (Hemiptera: Aphididae), in predatory ladybird beetles (species of the genera Adonia, Coccinella, Hippodamia, and Propylea) using the gut homogenate of Adonia variegata (Goeze) (Coleoptera: Coccinellidae) adults which had fed on S. avenae as immunogen. The McAb was selected by screening hybridoma lines for antibodies that bound with the semi‐digested aphid proteins in ladybirds. A double antibody sandwich enzyme‐linked immuno‐sorbent assay (ELISA) using ClonotypingTM System/HRP showed that it belonged to the IgG2a isotype. It did not cross‐react with any of the 21 arthropod species tested besides the ladybird beetles fed on S. avenae with an indirect ELISA. It could still detect the semi‐digested proteins in the gut of a ladybird adult, kept at 25 °C, that had ingested one aphid 6 days before. The extended antigen detection period and the high specificity of the antibody indicated that EGA‐4A9 could be used to study interactions between English grain aphids and their ladybird predators in the field. Between 28 and 72% of coccinellids collected from the field were positive for English grain aphid protein by ELISA. The percentage of McAb‐positive predatory ladybird beetles was positively correlated with the density of S. avenae in wheat fields.
Ecological thresholds: an assessment of methods to identify abrupt changes in species–habitat relationships
Authors: Francesco Ficetola Gentile , Denoël Mathieu
Published: September 2009

Habitat thresholds are usually defined as “points of abrupt change” in the species–habitat relationships. Habitat thresholds can be a key tool for understanding species requirements, and provide an objective definition of conservation targets, by identifying when habitat loss leads to a rapid loss of species, and the minimum amount of habitat necessary for species persistence. However, a large variety of statistical methods have been used to analyse them. In this context, we reviewed these methods and, using simulated data sets, we tested the main models to compare their performance on the identification of thresholds. We show that researchers use very different analytical tools, corresponding to different operational definitions of habitat thresholds, which can considerably affect their detection. Piecewise regression and generalized additive models allow both the distinction between linear and nonlinear dynamics, and the correct identification of break point position. In contrast, other methods such as logistic regression fail because they may incorrectly detect thresholds in gradual patterns, or they may over or underestimate the threshold position. In conservation or habitat modelling, it is important to focus efforts efficiently and the inappropriate choice of statistical methods may have detrimental consequences.
Modelling the impact of Hieracium spp. on protected areas in Australia under future climates
Authors: Beaumont Linda J. , Gallagher Rachael V. , Downey Paul O. , Thuiller Wilfried , Leishman Michelle R. , Hughes Lesley
Published: September 2009

Anthropogenically‐induced climate change is one of the most important global threats to biodiversity. Understanding its impact on the distribution of exotic plant species is critical for developing effective adaptation and management strategies. However, there is insufficient information currently available on the biodiversity at risk from 1) exotic plant invasions, 2) climate change, and 3) the interaction between these two major threats, to develop such strategies. We use ecological niche models as a first step to identify zones inside and outside Australian protected areas that may be most at risk from invasions of three species of Hieracium (hawkweeds) under current and future (2030 and 2070) climate scenarios, should current control and eradication methods fail. These perennial herbs are native to Europe and invasive to New Zealand and North America. Naturalised in Australia, hawkweeds threaten native tussock grasslands and the grazing industry, and have been placed on the National Alert List. Using eight ecological niche models currently available in the software package BIOMOD, we found that these species have yet to realize the extent of their climatic distribution under present day climate in Australia. As climate change accelerates, the climatic range of hawkweeds was projected to contract overall. However, much of the Australian Alps, which contain large contiguous tracts of reserves and many endemic species, will continue to retain climatically suitable areas for hawkweeds through to 2070. These results emphasise the need for ongoing monitoring as well as focused control to minimize the likelihood of hawkweeds realizing their invasive potential in protected areas and beyond.
Changes in home range size of African lions in relation to pride size and prey biomass in a semi‐arid savanna
Authors: Loveridge Andrew J. , Valeix Marion , Davidson Zeke , Murindagomo Felix , Fritz Hervé , Macdonald David W.
Published: September 2009

Within‐population studies are needed to investigate the extent of, and the factors underlying, intraspecific variation in home range size. We used data from 12 female and 8 male adult lions instrumented with GPS radio‐collars to describe the ranging behaviour of lions in a population from a dystrophic semi‐arid savanna, Hwange National Park, Zimbabwe. We measured prey availability at the home range scale in 2003, 2004, and 2005. For females, home range size increased as pride biomass increased, which is strongly suggestive of expansionism. Once controlled for pride biomass, home range size decreased as prey biomass increased. Pride ranges responded to changes in food abundance on an annual timescale rather than on a seasonal timescale. Female home range size was influenced by the abundance of kudu in the early dry season, whereas it was influenced by buffalo and young elephant abundance in the late dry season. This study shows that female home range size is mainly driven by the size of the pride, but also by prey abundance. Furthermore, female seasonal home range size may be determined, not only by prey abundance, but also by prey dispersion in the landscape. Home range size of males was driven by both prey biomass and the density of female prides.
Patterns of invertebrate density and taxonomic richness across gradients of area, isolation, and vegetation diversity in a lake‐island system
Authors: Jonsson Micael , Yeates Gregor W. , Wardle David A.
Published: September 2009

Over the past half century, ecologists have tried to unravel the factors that drive species richness patterns in ecological communities. One influential theory is island biogeography theory (IBT), which predicts that island or habitat area and isolation are drivers of species richness. However, relatively few studies testing IBT have considered invertebrate or belowground communities, and it is unclear as to whether the predictions made by IBT hold for these communities. Other theories predict that habitat characteristics such as vegetation diversity may be important drivers of invertebrate species richness. To investigate patterns of invertebrate density and species richness across gradients of area, isolation, and vegetation diversity, we used a system of 30 lake islands in the boreal zone of northern Sweden. We assessed density and taxonomic richness of ground‐dwelling spiders, web‐building spiders, beetles, collembolans, mites, and nematodes, for all islands during two consecutive summers. For all invertebrate groups, both density and taxonomic richness were either neutrally or negatively related to island size, and either neutrally or positively related to island isolation. Meanwhile the density and taxonomic richness for several groups was positively related to vegetation diversity (i.e. habitat heterogeneity). In multiple regression analyses, island size was often the single best predictor for both invertebrate density and taxonomic richness, but in some cases island size and isolation in combination explained more variation than each factor considered singly. Contrary to IBT predictions, invertebrate density and richness was never positively related to island size or negatively related to island isolation. Instead, our results suggest that plant diversity (and thus habitat heterogeneity) was the main driver of the patterns that we found, although other factors could have some influence. We conclude that several factors, but not necessarily those predicted as important by IBT, are important in determining invertebrate abundance and species richness in island systems.
Landscape fragmentation influences winter body mass of roe deer
Authors: Hewison A.J. Mark , Morellet Nicolas , Verheyden Helene , Daufresne Tanguy , Angibault Jean‐Marc , Cargnelutti Bruno , Merlet Joel , Picot Denis , Rames Jean‐Luc , Joachim Jean , Lourtet Bruno , Serrano Emmanuel , Bideau Eric , Cebe Nicolas
Published: September 2009

Body size of large herbivores is a crucial life history variable influencing individual fitness‐related traits. While the importance of this parameter in determining temporal trends in population dynamics is well established, much less information is available on spatial variation in body size at a local infra‐population scale. The relatively recent increase in landscape fragmentation over the last century has lead to substantial spatial heterogeneity in habitat quality across much of the modern agricultural landscape. In this paper, we analyse variation in body mass and size of roe deer inhabiting a heterogeneous agricultural landscape characterised by a variable degree of woodland fragmentation. We predicted that body mass should vary in relation to the degree of access to cultivated meadows and crops providing high quality diet supplements. In support of our prediction, roe deer body mass increased along a gradient of habitat fragmentation, with the heaviest deer occurring in the most open sectors and the lightest in the strict forest environment. These spatial differences were particularly pronounced for juveniles, reaching >3 kg (ca 20% of total body mass) between the two extremes of this gradient, and likely have a marked impact on individual fates. We also found that levels of both nitrogen and phosphorous were higher in deer faecal samples in the more open sectors compared to the forest environment, suggesting that the spatial patterns in body mass could be linked to the availability of high quality feeding habitat provided by the cultivated agricultural plain. Finally, we found that adults in the forest sector were ca 1 kg lighter for a given body size than their counterparts in the more open sectors, suggesting that access to nutrient rich foods allowed deer to accumulate substantial fat reserves, which is unusual for roe deer, with likely knock‐on effects for demographic traits and, hence, population dynamics.
Functional diversity in fruit‐frugivore interactions: a field experiment with Mediterranean mammals
Authors: Fedriani José M. , Delibes Miguel
Published: September 2009

Using field seed sowings, we assessed how four mammal species (Meles meles, Vulpes vulpes, Sus scrofa, and Oryctolagus cuniculus) influenced seed germination in three fleshy‐fruited Mediterranean shrubs (Corema album, Pyrus bourgaeana, and Rubus ulmifolius). We predicted that gut passage and removal away from mother plants would enhance the quantity, speed, and asynchrony of seed germination. Results showed that percent germination was altered by gut passage, but that the magnitude and even the direction of such effects varied according to plant and disperser species. Likewise, dispersal away from mother plants affected the percentage and germination speed in some species but not others. Gut passage increased asynchrony of germination in Rubus and Pyrus, and removal from the mother plant increased asynchrony in Rubus, which likely enhances plant fitness in unpredictable environments. Gut passage generally had a stronger effect on germination than removal away from mother plants, but for some species both factors were similarly influential. Therefore, the combined effects of both seed dispersal services varied individually among fruit and frugivore species, leading to unusually high functional diversity in this seed dispersal mutualism.
Evaluation of four hematology and a chemistry portable benchtop analyzers using non‐human primate blood
Authors: Snider C.L. , Dick Jr E.J , McGlasson D.L. , Robbins M.C. , Sholund R.L. , Bommineni Y.R. , Hubbard G.B.
Published: September 2009

Background Near patient testing (NPT) and point‐of‐care testing (POCT) using portable benchtop analyzers has become necessary in many areas of the medical community, including biocontainment.

Methods We evaluated the Beckman AcT diff, Abaxis Vetscan HMII (two instruments), Abbott Cell‐Dyn 1800, and Abaxis Vetscan VS2 for within‐run precision and correlation to central laboratory instruments using non‐human primates blood.

Results Compared with the central laboratory instruments, the Beckman AcT diff correlated on 80%; the HMII instruments on 31% and 44%, the CD1800 on 31%, and the VS2 on 71% of assays. For assays with published manufacturers precision guidelines, the AcT diff met all nine, the HMII instruments met one and six of six, and the CD 1800 met one of six.

Conclusions Laboratories using NPT/POCT must test their individual instruments for precision and correlation, identify assays that are reliable, and exclude or develop supplemental procedures for assays that are not.
Spontaneous gallbladder pathology in baboons
Authors: Slingluff J.L. , Williams J.T. , Blau L. , Blau A. , Dick Jr E.J , Hubbard G.B.
Published: September 2009

Background  Gallbladder pathology (GBP) is a relatively uncommon, naturally occurring morbidity in both baboons and humans.

Methods  A retrospective analysis was performed on 7776 necropsy reports over a 20 year period to determine the prevalence of baboon GBP.

Results  Ninety‐seven cases of GBP were identified, yielding a 20 year population prevalence of 1.25%. GBP is more common in adult female baboons, occurring with a female to male ratio of nearly 2:1. Among gallbladder pathologies, cholecystitis (35.1%) and cholelithiasis (29.9%) were the most prevalent abnormalities, followed by hyperplasia (16.5%), edema (15.5%), amyloidosis (5.2%), fibrosis (4.1%), necrosis (4.1%), and hemorrhage (1.0%).

Conclusion  Many epidemiologic similarities exist between GBP in baboons and humans suggesting that the baboon may serve as a reliable animal model system for investigating GBP in humans.