bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenicity and host specificity of Brazilian and African isolates of the acaropathogenic fungus Neozygites tanajoae to mite species associated with cassava
Authors: Agboton B. V. , Hanna R. , Hountondji F. C. C. , Von Tiedemann A.
Published: May 2009

Neozygites tanajoae is a host‐specific acaropathogen introduced in the late 1990s from Brazil into cassava fields in West Africa for biocontrol of the cassava green mite (Mononychellus tanajoa). Local African isolates of N. tanajoae are morphologically similar to introduced Brazilian strains but the two origins can be distinguished by diagnostic PCR. In this study it was explored whether differential traits in acaropathogenic performance and host specificity exist between Brazilian and African isolates. Pathogenicity and host specificity of two Brazilian and two African isolates of N. tanajoae were compared in leaf discs laboratory bioassays or on whole cassava plants in the greenhouse by exposing adult female mites to inoculum delivered from N. tanajoae infested mite mummies. The results show that all four N. tanajoae isolates caused significant mortality of M. tanajoa, both on leaf discs and on whole plants. However, on leaf discs the Brazilian isolate collected directly from Alto Alegre in Brazil (Brazil–Brazil isolate) caused a significantly higher mortality (80%) than the Brazilian isolate collected about 9 years post‐release from a field in Adjohoun (Brazil–Benin isolate) (61.3%). The two African isolates collected in Benin and Tanzania caused a mortality similar to the African–Brazilian isolate (62.3% and 61.3% respectively). On whole cassava plants, the four fungal isolates did not show any significant differences in incidence of M. tanajoa infection. The host specificity study was conducted on leaf discs against a collection of mite species typically associated with cassava plants in Africa, Typhlodromalus aripo, Euseius fustis, Tetranychus urticae and Oligonychus gossypii. It demonstrated that the African and Brazilian isolates of N. tanajoae had similar host specificity for M. tanajoa.
Effect of renin–angiotensin system inhibitors on prevention of peritoneal fibrosis in peritoneal dialysis patients
Authors: JING SUN , KEZHOU YU , HONG ZHANG , QUN WANG , RONG WANG
Published: May 2009

Aim:  Long‐term peritoneal dialysis (PD) may lead to peritoneal fibrosis and ultrafiltration failure. It had been demonstrated that the renin–angiotensin system (RAS) plays a key role in the regulation of peritoneal function in rats on PD. We investigated the effects of angiotensin‐converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) on long‐term PD patients.

Methods:  We analyzed data from 66 patients treated with PD therapy at our centre for at least 12 months retrospectively, during which time at least two peritoneal equilibration tests (PET) were performed. Thirty‐eight patients were treated with ACE/angiotensin II (AII) inhibitors (ACE/ARB group); the other 28 received none of the above drugs during the entire follow up (control group). The expression of fibronectin, transforming growth factor‐β1 (TGF‐β1), Aquaporin1 (AQP1) and vascular endothelial growth factor (VEGF) in the overnight effluent were examined by enzyme‐linked immunosorbent assay.

Results:  The demographic data of the two groups showed no difference during the study. No difference between the groups was found with respect to residual renal function (RRF) at the start for both groups by the end of follow up, decreased in the vast majority of patients from both groups (P = 0.014). After 12 months, a significant difference in ultrafiltration was found between the two groups: in the control group it had decreased, while it had not changed in the ACE/ARB group (P < 0.05). In comparison with the baseline level, expression of fibronectin, TGF‐β1 and VEGF in dialysate effluent were significantly increased except for AQP1 in the control group (P < 0.05), but not in the ACE/ARB group (P > 0.05).

Conclusion:  The findings suggest that ACE/AII inhibitors appeared to have a slower rate of decline in ultrafiltration and RRF, effectively protect against peritoneal fibrosis in long‐term peritoneal dialysis. Long‐term follow up seems to be required to draw more conclusions.
Biodiversity scales from plots to biomes with a universal species–area curve
Authors: Harte John , Smith Adam B. , Storch David
Published: May 2009

Classic theory predicts species richness scales as the quarter‐power of area, yet species–area relationships (SAR) vary widely depending on habitat, taxa, and scale range. Because power‐law SAR are used to predict species loss under habitat loss, and to scale species richness from plots to biomes, insight into the wide variety of observed SAR and the conditions under which power‐law behavior should be observed is needed. Here we derive from the maximum entropy principle, a new procedure for upscaling species richness data from small census plots to larger areas, and test empirically, using multiple data sets, the prediction that up to an overall scale displacement, nested SAR lie along a universal curve, with average abundance per species at each scale determining the local slope of the curve. Power‐law behaviour only arises in the limit of increasing average abundance, and in that limit, the slope approaches zero, not ¼. An extrapolation of tree species richness in the Western Ghats to biome scale (60 000 km2) using only census data at plot scale (¼ ha) is presented to illustrate the potential for applications of our theory.
The spermatozoon of the Old Endemic Australo‐Papuan and Philippine rodents – its morphological diversity and evolution
Authors: Breed William G. , Leigh Christopher M.
Published: May 2009

Breed, W.G. and Leigh, C.M. 2010. The spermatozoon of the Old Endemic Australo‐Papuan and Philippine rodents – its morphological diversity and evolution.—Acta Zoologica (Stockholm) 91: 279–294

The spermatozoon of most murine rodents contains a head in which there is a characteristic apical hook, whereas most old endemic Australian murines, which are part of a broader group of species that also occur in New Guinea and the Philippines, have a far more complex sperm form with two additional ventral processes. Here we ask the question: what is the sperm morphology of the New Guinea and Philippines species and what are the trends in evolutionary changes of sperm form within this group? The results show that, within New Guinea, most species have a highly complex sperm morphology like the Australian rodents, but within the Pogonomys Division some species have a simpler sperm morphology with no ventral processes. Amongst the Philippines species, many have a sperm head with a single apical hook, but in three Apomys species the sperm head contains two additional small ventral processes, with two others having cockle‐shaped sperm heads. When these findings are plotted on a molecular phylogeny, the results suggest that independent and convergent evolution of highly complex sperm heads containing two ventral processes has evolved in several separate lineages. These accessory structures may support the sperm head apical hook during egg coat penetration.
ENVIRONMENTAL CONSCIOUSNESS, REPUTATION AND VOLUNTARY ENVIRONMENTAL INVESTMENT
Authors: LIU CHIA‐YING , WU CHI‐HSIN
Published: May 2009

This note attempts to explore the driving force behind firms' voluntary environmental investment and to provide an alternative viewpoint to the traditional notion of environmental investment. We show that, if consumers are environmentally conscious, then firms' environmental investment will enhance their environmentally‐based reputation and effectively stimulate consumer demand for the product. Thus, some firms will voluntarily engage in environmental investment. In addition, it is also found that when consumers become more environmentally conscious, in the steady state a high level of environmental investment may be associated with higher output. This result potentially provides an explanation as to why environmental quality may increase with output.
ADDICTIVE DRUG USE MANAGEMENT POLICIES IN A LONG‐RUN ECONOMIC MODEL*
Authors: CLARKE HARRY , BYFORD MARTIN
Published: May 2009

A model of illicit, addictive drug use is proposed when users have foresight. Impacts of drug use penalties, penalties on drug use‐related crime, support for drug user rehabilitation as well as the effects of health‐related, harm‐minimisation policies are analysed. In the short run, government policies impact only on the drug use intensities of existing addicted and casual users. Longer term policy‐induced user‐cost changes impact on new user and addict numbers through their effect on recruitment into addiction and quit dynamics. Effects of policies on user numbers, usage intensities and impacts on long‐run social costs are analysed over this long‐term horizon. The model provides a setting for analysing the long‐run effects of illicit drug management policies on the social costs of illicit drug use and allows assessment of drug use abstinence and harm minimisation policy tradeoffs.
MODELLING PRODUCTIVITY EFFECTS OF TRADE OPENNESS: A DUAL APPROACH*
Authors: PAUL SATYA , MARKS ANDREW
Published: May 2009

A cost function framework is used to model the productivity effect of trade openness in terms of cost saving. The idea of ‘cost saving’ is closer to the entrepreneur's view of productivity. An entrepreneur would expect a reduction in the cost of production if trade openness brings any benefits to their firm. The output‐enhancing (primal) productivity effect of openness is obtainable from the cost‐saving (dual) productivity effect through the cost‐output link. The cost‐function framework also enables us to investigate whether trade openness induces firms to adopt a technology that is biased towards the use or saving of any factor of production. An empirical exercise based on time series data for the Australian two‐digit manufacturing industries reveals significant cost‐saving and output‐enhancing productivity effects of trade openness. Trade openness is biased towards the saving of labour and the use of capital. These results are quite insensitive to the choice of alternative measures of openness.
ENDOGENOUS TIMING IN A MIXED DUOPOLY AND PRIVATE DUOPOLY –‘CAPACITY‐THEN‐QUANTITY’ GAME: THE LINEAR DEMAND CASE*
Authors: LU YUANZHU , PODDAR SOUGATA
Published: May 2009

We consider a game of endogenous timing of sequential choice of capacity and quantity with observable delay in a mixed duopoly and a private duopoly. In mixed duopoly, we find that a simultaneous play at the capacity stage or at the quantity stage can never be supported as subgame perfect Nash equilibrium (SPNE); whereas a simultaneous play at each stage turns out to be the unique SPNE in a private duopoly. In mixed duopoly there is multiplicity of equilibria and all SPNEs require sequentiality at the capacity as well as quantity stage.
PRESENTISM, TRUTHMAKERS, AND GOD
Authors: RHODA ALAN R.
Published: May 2009

The truthmaker objection to presentism (the view that only what exists now exists simpliciter) is that it lacks sufficient metaphysical resources to ground truths about the past. In this paper I identify five constraints that an adequate presentist response must satisfy. In light of these constraints, I examine and reject responses by Bigelow, Keller, Crisp, and Bourne. Consideration of how these responses fail, however, points toward a proposal that works; one that posits God's memories as truthmakers for truths about the past. I conclude that presentists have, in the truthmaker objection, considerable incentive to endorse theism.
ON NATURALIZING THE EPISTEMOLOGY OF MATHEMATICS
Authors: ROLAND JEFFREY W.
Published: May 2009

In this paper, I consider an argument for the claim that any satisfactory epistemology of mathematics will violate core tenets of naturalism, i.e. that mathematics cannot be naturalized. I find little reason for optimism that the argument can be effectively answered.
MINDING OTHERS' BUSINESS
Authors: STOHR KAREN
Published: May 2009

What do we do when a loved one is seriously messing up her life? While Kantianism describes the predicament nicely as a tension between love and respect, it is not well‐suited to resolving it. Kantian respect prevents minding another's business in cases where love demands it. Virtue ethics can readily explain the predicament as a tension between the virtues of sympathy and humility. Moreover, by changing the focus away from the other as a setter of ends and toward the would‐be‐benefactor's own degree of practical wisdom, virtue ethics permits a more nuanced set of loving responses to self‐destructive people.
Reinterpreting Sellars in the Light of Brandom, McDowell, and A. D. Smith
Authors: Olsen Niels Skovgaard
Published: May 2009

Abstract: The intent of this paper is to indicate a development in Sellars' writings which points in another direction than the interpretations offered by Brandom, McDowell, and A. D. Smith. Brandom and McDowell have long claimed to preserve central insights of Sellars's theory of perception; however, they disagree over what exactly these insights are. A. D. Smith has launched a critique of Sellars in chapter 2 of his book The Problem of Perception which is so penetrating that it would tear Sellars' philosophy of perception apart if it were adequate. However, I try to show firstly that Brandom's and McDowell's interpretations are unsatisfying when Sellars' late writings are taking into consideration. And secondly that we can give another interpretation of Sellars that is not vulnerable to some of the problems of which Smith accuses Sellars.
Intra‐Left Atrial Mechanical Delay Detected by Tissue Doppler Echocardiography Can Be a Useful Marker for Paroxysmal Atrial Fibrillation
Authors: Deniz Ali , Yavuz Bunyamin , Aytemir Kudret , Hayran Mutlu , Kose Sedat , Okutucu Sercan , Tokgozoglu Lale , Kabakci Giray , Oto Ali
Published: May 2009

Objectives: There are some clinical and echocardiographic parameters to predict paroxysmal atrial fibrillation (PAF), but more sensitive predictors are needed. Tissue Doppler imaging may be a sensitive method for this purpose. Methods: Thirty‐four patients with PAF and 31 control subjects were studied. Time intervals from the beginning of P‐wave to beginning of A‐wave from lateral and septal mitral and right ventricular tricuspid annuli in tissue Doppler imaging were recorded. The differences between these intervals gave the mechanical delays between/within the corresponding atria. Results: There were no differences between groups with regard to age. PAF patients were found to have increased left atrial dimension and intra‐left atrial mechanical delay. Twenty‐five milliseconds was calculated as cutoff value to predict PAF. P‐wave dispersion was found to be increased in PAF. Conclusions: This study shows an increase in intra‐left atrial mechanical delay in PAF patients. This method can be used as an early marker to detect PAF.
Association between Left Atrium Enlargement and Intradialytic Hypotension: Role of Diastolic Dysfunction in the Hemodynamic Complications during Hemodialysis
Authors: Barberato Silvio H. , Misocami Marcio , Pecoits‐Filho Roberto
Published: May 2009

Symptomatic intradialytic hypotension (IH) continues to be an important complication of hemodialysis treatment. It has been suggested that patients with left ventricular (LV) diastolic dysfunction may be more sensitive to the effects of reduced cardiac filling. Left atrial volume index (LAVi) reflects the chronicity of exposure to elevated LV filling pressures. The aim of this study was to identify the association between echocardiographic disease, in particular left atrium enlargement, and IH. Echocardiograms obtained in 172 patients undergoing hemodialysis in sinus rhythm and with no significant valvular or pericardial disease were analyzed. The independent association between LAVi and IH was assessed using multivariate logistic regression. IH was identified in 27 patients (16%). The patients who experienced the hypotensive episodes had a greater prevalence of previous heart failure (59% vs 22%, P < 0.001), systolic dysfunction (33% vs 14%, P = 0.003), and LAVi > 35 mL/m2 (59% vs 32%, P = 0.008). No differences were noted for age, gender, body mass index, duration of dialysis, blood pressure, use of drugs, and proportions of arterial hypertension, diabetes, LV hypertrophy and diastolic dysfunction by Doppler. After multivariate analysis, only heart failure and LAVi > 35 mL/m2 were seen to be independent predictors of IH. The finding of left atrium enlargement in patients undergoing hemodialysis may be useful in the clinical prediction of IH.
The Effects of Antihypertensive Treatment on the Doppler‐Derived Myocardial Performance Index in Patients with Hypertensive Left Ventricular Hypertrophy: Results from the Swedish Irbesartan in Left Ventricular Hypertrophy Investigation Versus Atenolol (SILVHIA)
Authors: Liljedahl Stefan , Kahan Thomas , Lind Lars , Ärnlöv Johan
Published: May 2009

Objectives: To investigate the effects of antihypertensive treatment on the Doppler‐derived myocardial performance index (MPI) in patients with hypertensive left ventricular hypertrophy. Methods: The MPI was measured at baseline and after 48 weeks of antihypertensive treatment in 93 participants of the SILVHIA trial, where individuals with primary hypertension and left ventricular hypertrophy were randomized to double blind treatment with either irbesartan or atenolol. Results: Antihypertensive treatment lowered MPI (mean difference −0.03 ± 0.01, P = 0.04). Changes in MPI by treatment were associated with changes in left ventricular ejection fraction (β‐coefficient −0.35 P = 0.005), stroke volume/pulse pressure (reflecting arterial compliance, β‐coefficient −0.39 P < 0.001) and peripheral vascular resistance (β‐coefficient 0.28 P < 0.04). Furthermore, there was a borderline significant association between changes in MPI and changes in E‐wave deceleration time (reflecting diastolic function, β‐coefficient 0.23, P = 0.06). No associations were found between changes in MPI and changes in blood pressure, E/A‐ratio, left ventricular mass index, relative wall thickness or heart rate. A stepwise multivariable regression model confirmed the association between changes in MPI and changes in ejection fraction and stroke volume/pulse pressure (all P < 0.05), as well as the trend for E‐wave deceleration time (P = 0.08), but not in the case of peripheral vascular resistance. Conclusion: The MPI exhibited a modest decrease after 48 weeks of antihypertensive treatment in patients with hypertensive left ventricular hypertrophy. Changes in MPI were associated with changes in left ventricular function and vascular compliance, rather than with changes in left ventricular remodeling or blood pressure.
Echo‐Tracking Assessment of Carotid Artery Stiffness in Patients with Aortic Valve Stenosis
Authors: Antonini‐Canterin Francesco , Roşca Monica , Beladan Carmen C. , Popescu Bogdan A. , Piazza Rita , Leiballi Elisa , Ginghină Carmen , Nicolosi Gian L.
Published: May 2009

Background: There is little information about mechanical properties of large arteries in patients (pts) with aortic stenosis (AS). Methods: Nineteen patients with AS (aortic valve area: 0.88 ± 0.29 cm2) and 24 control subjects without AS but with a similar distribution of risk factors were recruited. β index, pressure‐strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AIx), and local pulse‐wave velocity (PWV) were obtained at the level of right common carotid artery (CCA) by a real time echo‐tracking system. Time to dominant peak of carotid diameter change waveform, corrected for heart rate (tDPc), and maximum rate of rise of carotid diameter (dD/dt) were measured. Systemic arterial compliance (SAC) was also calculated. Parameters of AS severity (mean gradient, valve area, stroke work loss [SWL]) were determined. Results: tDPc was higher in patients with AS than in controls (7.9 ± 0.6 vs. 6.6 ± 0.7, P < 0.0001) while dD/dt was lower (5.3 ± 3.6 mm/s vs. 7.8 ± 2.8 mm/s, P = 0.01). AIx was significantly higher in AS group (32.5 ± 13.6% vs. 20.6 ± 12.2%, P = 0.005) and had a linear correlation both with tDPc (r = 0.63, P < 0.0001) and with dD/dt (r =−0.38, P = 0.01). There was a significant correlation between carotid AC and SAC (r = 0.49, P = 0.03), but only carotid AC was related to SWL (r = 0.51, P = 0.02), while SAC was not (P = 0.26).Conclusions: AIx was the only parameter of arterial rigidity found to be higher in patients with AS than in controls. Carotid AC showed a significant correlation with SAC and it seemed to be more closely related to AS severity than to SAC.
Doppler‐Derived Myocardial Performance Index in Patients with Impaired Left Ventricular Relaxation and Preserved Systolic Function
Authors: Fernandes José Maria G. , Rivera Ivan Romero , De Oliveira Romão Benício , Mendonça Maria Alayde , Vasconcelos Miriam Lira Castro , Carvalho Antônio Carlos , Campos Orlando , De Paola Ângelo Amato V. , Moisés Valdir A
Published: May 2009

Background: The Doppler‐derived myocardial performance index (MPI) has been used in the evaluation of left ventricular (LV) function in several diseases. In patients with isolated diastolic dysfunction, the diagnostic utility of this index remains unclear. The aim of this study was to determine the diagnostic utility of MPI in patients with systemic hypertension, impaired LV relaxation, and normal ejection fraction. Methods: Thirty hypertensive patients with impaired LV relaxation were compared to 30 control subjects. MPI and its components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and the ejection time (ET), were measured from LV outflow and mitral inflow Doppler velocity profiles. Results: MPI was higher in patients than in control subjects (0.45 ± 0.13 vs 0.37 ± 0.07 P < 0.0029). The increase in MPI was due to the prolongation of IRT without significant change of ICT and ET. MPI cutoff value of ≥0.40 identified impaired LV relaxation with a sensitivity of 63% and specificity of 70% while an IRT >94 ms had a sensitivity of 67% and specificity of 80%. Multivariate analysis identified relative wall thickness, mitral early filling wave velocity (E), and systolic myocardial velocity (Sm) as independent predictors of MPI in patients with hypertension. Conclusions: MPI was increase in patients with hypertension, diastolic dysfunction, and normal ejection fraction but was not superior to IRT to detect impaired LV relaxation.
Is the Presence of Mitral Annular Calcification Associated with Poor Left Atrial Function?
Authors: Ariyarajah Vignendra , Apiyasawat Sirin , Barac Ivan , Spodick David H.
Published: May 2009

Introduction: Mitral annular calcification (MAC) is characterized by calcium and lipid deposition in the annular fibrosa of the mitral valve. MAC is associated with cardiovascular events but little is known of its association with left atrial (LA) function. Methods: We prospectively obtained 12‐lead electrocardiograms (ECGs) and transthoracic echocardiograms (TTE) on patients scheduled for nonemergent echocardiographic assessment at a tertiary care hospital. MAC was graded as 0 = none, 1 = mild, 2 = moderate, 3 = severe. LA linear and volume measurements (stroke volume, LA passive emptying fraction, LA active emptying fraction and LA kinetic energy) were done specifically in addition to commonly measured TTE parameters. Results: From the 124 considered for the study, 72 patients remained (aged 68±18 years; 44% male) after excluding those with poor ECG tracings and/or poor TTE images. Eighteen patients had MAC; mild MAC = 14, moderate MAC = 3, severe MAC = 1. When patients with MAC were compared to those without MAC, no significant difference was noted, except for LA linear dimension index (2.1±0.4 vs. 1.9±0.3 cm/m2; P = 0.03). For those with mild and moderate MAC, a trend was noted toward lower LA function with increasing MAC severity. In addition, significant differences were noted between those with and without interatrial conduction delay, where those with such delay had significantly impaired LA stroke volume (9.8±3 vs. 19.93±4 ml; P < 0.0001), LA active emptying fraction (18.83±8 vs. 65.71±9%; P < 0.0001) and LA total/reservoir fraction (39.54±6 vs. 75.1±6%; P < 0.0001). Conclusions: MAC is associated with increase in LA linear dimension on TTE and may be equally represented with lower overall LA function. Further study in a much larger cohort is warranted to delineate these and other potential associations of MAC.
An Echocardiographic Study of the Limitations of the Tei Index in Aortic Stenosis
Authors: Sud Sachin , Massel David
Published: May 2009

Background: The omnibus Tei index, the sum of isovolumic contraction and relaxation times divided by the ejection time, is a good indicator of global cardiac function. However, these time intervals can be influenced by valvular heart disease and the role of the Tei index among patients with aortic stenosis (AS) and left ventricular systolic dysfunction remains incompletely defined. Methods: Doppler time intervals were measured retrospectively by two observers, and the Tei index were calculated on 80 patients with various degrees of left ventricular systolic dysfunction and severity of AS. Differences between observers were resolved by consensus. Ejection fraction (EF) was visually estimated, and the aortic valve area (AVA) was calculated using the continuity equation. Results: The mean AVA was 1.1±0.5 cm2 and the mean EF was 0.39±0.15. Although correlation (r = 0.61, P < 0.001) and agreement (intraclass correlation coefficient=0.55) for the Tei index were satisfactory, there were significant differences between observers (P < 0.001). Using consensus data, the mean Tei index was 0.32±0.20 and significantly lower among patients with severe compared with less severe AS (P=0.01). The index varied inversely with left ventricular function (P=0.003). However, receiver operating characteristic analysis shows that the Tei index lacks discrimination in accurately identifying poor left ventricular function or severe AS or both. Conclusion: The Tei index varies inversely with systolic ventricular function (low index with good EF) and positively with severity of AS (low index with smaller valve area). As such, it may have limited utility among individual patients with AS.
The Potential Impact of Contemporary Transthoracic Echocardiography on the Management of Patients with Native Valve Endocarditis: A Comparison with Transesophageal Echocardiography
Authors: Casella Francesco , Rana Bushra , Casazza Giovanni , Bhan Amit , Kapetanakis Stam , Omigie Joe , Reiken Joseph , Monaghan Mark J.
Published: May 2009

Background: Between 1987 and 1994, several studies demostrated transthoracic echocardiography (TTE) to be less sensitive than transesophageal echocardiography (TEE) in detecting native valve endocarditis. Recent technologic advances, especially the introduction of harmonic imaging and digital processing and storage, have improved TTE image quality. The aim of this study was to determine the diagnostic accuracy of contemporary TTE. Methods: Between 2003 and 2007, 75 patients underwent both TTE and TEE for clinically suspected infective endocarditis. The diagnostic accuracy of TTE was assessed using transesophageal echocardiography as the gold standard for diagnosis of endocarditis. Results: Of the 75 patients in this study, 33 were found to be positive by TEE. The sensitivity for detection of infective endocarditis by TTE was 81.8%. It provided good image quality in 81.5% of cases; in these patients sensitivity was even greater (89.3%). Conclusion: Contemporary TTE has improved the diagnostic accuracy of infective endocarditis by ameliorating image quality; it provides an accurate assessment of endocarditis and may reduce the need for TEE.
Interdependence of Cardiac and Endothelial Function in Patients with Symptomatic Chronic Heart Failure of Nonischemic Etiology
Authors: Vittorio Timothy J. , Zolty Ron , Garg Parveen K. , Sarswat Nitasha , Tseng Chi‐Hong , Jorde Ulrich P. , Colombo Paolo C.
Published: May 2009

Objective: Endothelial dysfunction has emerged as a therapeutic target in patients with chronic congestive heart failure (CHF). Endothelial dysfunction may impair left ventricular (LV) systolic function by increasing systemic vascular resistance. Conversely, LV impairment may negatively impact endothelial function by reducing shear stress and vascular nitric oxide (NO) bioavailability. This study was undertaken to determine the association between LV and endothelial function in patients with CHF. Methods: Echocardiographic and vascular ultrasound studies were performed to measure left ventricular ejection fraction (LVEF) and brachial artery flow‐mediated vasodilatation (FMD) in 30 subjects with stable New York Heart Association class II–III CHF. All patients received optimal medical therapy. Results: LVEF averaged 25 ± 9% and brachial artery FMD 1.3 ± 2.4%. LVEF strongly correlated with FMD among all patients (r = 0.64, P< 0.001) and among those patients with nonischemic (n = 19, r = 0.66, P = 0.002), but not in patients with ischemic etiology (n = 11, r = 0.27, P = 0.42). Conclusions: LVEF and endothelium‐dependent NO vasodilatation are strongly correlated in stable ambulatory patients with systolic CHF of nonischemic etiology. Our study underscores the mutual interaction between central cardiac and peripheral vascular function, thus strengthening a mechanistic rationale for the systemic beneficial effects of interventions targeting either the heart or the vascular endothelium in CHF.
Aortic Upper Wall Tissue Doppler Image Velocity: Relation to Aortic Elasticity and Left Ventricular Diastolic Function
Authors: Suh Soon Yong , Kim Eung Ju , Choi Cheol Ung , Na Jin Oh , Kim Sung Hea , Kim Hyun Joong , Han Seong Woo , Chung Sang Man , Ryu Kyu Hyung , Park Chang Gyu , Seo Hong Seog , Oh Dong Joo
Published: May 2009

Background: Aortic stiffening contributes to the left ventricular (LV) afterload, hypertrophy, and substrate for diastolic dysfunction. It is also known that aortic elastic properties could be investigated with color tissue Doppler imaging (TDI) in aortic upper wall. The purpose of this study is to evaluate the relation of aortic upper wall TDI and aortic stiffness and other parameters of LV diastolic function. Methods: We examined aortic upper wall by TDI at the 3 cm above the aortic valves because of patient's chest discomfort or dyspnea. We excluded the patient with arterial hypertension or reduced left ventricular ejection fraction (LVEF) or significant valvular heart disease. So a total of 126 (mean age 53.8 ± 13.9 years, male 49.2%) patients were enrolled in this study and divided normal LV filling group (N = 31) and abnormal LV filling group (N = 95). Results: Aortic upper wall early systolic velocity and late diastolic velocity were not different between the two groups. Only aortic upper wall early diastolic velocity (AWEDV) was related to aortic stiffness index (r =−0.25, P = 0.008), distensibility (r = 0.28, P = 0.003), early diastolic (Em) (r = 0.45, P = 0.001), E/Em (r =−0.26, P = 0.003), and significantly reduced in abnormal LV filling group (6.19 ± 2.50 vs 8.18 ± 2.87, P = 0.001). Conclusions: AWEDV is decreased significantly in abnormal LV filling patients. It is statistically related to aortic stiffness, distensibility and parameters of abnormal LV filling, Em, E/Em. TDI velocity of the aortic upper wall can be a helpful tool for evaluating aortic stiffness, distensibility, and diastolic function.
Involvement of Vps33a in the Fusion of Uroplakin‐Degrading Multivesicular Bodies with Lysosomes
Authors: Guo Xuemei , Tu Liyu , Gumper Iwona , Plesken Heide , Novak Edward K. , Chintala Sreenivasulu , Swank Richard T. , Pastores Gregory , Torres Paola , Izumi Tetsuro , Sun Tung‐Tien , Sabatini David D. , Kreibich Gert
Published: May 2009

The apical surface of the terminally differentiated mouse bladder urothelium is largely covered by urothelial plaques, consisting of hexagonally packed 16‐nm uroplakin particles. These plaques are delivered to the cell surface by fusiform vesicles (FVs) that are the most abundant cytoplasmic organelles. We have analyzed the functional involvement of several proteins in the apical delivery and endocytic degradation of uroplakin proteins. Although FVs have an acidified lumen and Rab27b, which localizes to these organelles, is known to be involved in the targeting of lysosome‐related organelles (LROs), FVs are CD63 negative and are therefore not typical LROs. Vps33a is a Sec1‐related protein that plays a role in vesicular transport to the lysosomal compartment. A point mutation in mouse Vps33a (Buff mouse) causes albinism and bleeding (Hermansky‐Pudlak syndrome) because of abnormalities in the trafficking of melanosomes and platelets. These Buff mice showed a novel phenotype observed in urothelial umbrella cells, where the uroplakin‐delivering FVs were almost completely replaced by Rab27b‐negative multivesicular bodies (MVBs) involved in uroplakin degradation. MVB accumulation leads to an increase in the amounts of uroplakins, Lysosomal‐associated membrane protein (LAMP)‐1/2, and the activities of β‐hexosaminidase and β‐glucocerebrosidase. These results suggest that FVs can be regarded as specialized secretory granules that deliver crystalline arrays of uroplakins to the cell surface, and that the Vps33a mutation interferes with the fusion of MVBs with mature lysosomes thus blocking uroplakin degradation.
Optimal spatio‐temporal hybrid sampling designs for ecological monitoring
Authors: Hooten Mevin B. , Wikle Christopher K. , Sheriff Steven L. , Rushin John W.
Published: May 2009

Question:Static sampling designs for collecting spatial data efficiently are being readily utilized by ecologists, however, most ecological systems involve a multivariate spatial process that evolves dynamically over time. Efficient monitoring of such spatio‐temporal systems can be achieved by modeling the dynamic system and reducing the uncertainty associated with the effect of design choice at future observation times. However, can we combine traditional techniques with dynamic methods to find optimal dynamic sampling designs for monitoring the succession of a herbaceous community?

Location:Lower Hamburg Bend Conservation Area, Missouri, USA (40°34′42″ lat. 95°45′38″ long.).

Methods:The dynamic nature of the system under study is modeled in such a way that uncertainty in the measurements and temporal process can both be accounted for. Both fixed and roving monitoring locations were used in conjunction with a spatio‐temporal statistical model to efficiently determine optimal locations of roving monitors over time based on the reduction of uncertainty in predictions.

Results:During the first 3 years of the study, roving monitors where held at fixed locations to allow for statistical parameter estimation from which to make predictions. Optimal monitoring locations for the remaining 2 years were selected based on the overall reduction in prediction uncertainty.

Conclusions:The dynamic and adaptive vegetation monitoring scheme allowed for the efficient collection of data that will be utilized for many future ecological studies. By optimally placing an additional set of monitoring locations, we were able to utilize information about the system dynamics when informing the data collection process.
Species properties and recovery from disturbance: Forest herbs buried by volcanic tephra
Authors: Zobel Donald B. , Antos Joseph A.
Published: May 2009

Question:How do forest herb species differ from each other in their spatial and temporal dynamics during recovery from volcanic disturbance, and how are dynamics related to species traits?

Location:Northeast of Mount St. Helens, Washington, USA.

Methods:Following deposition of volcanic tephra in 1980, we measured herb density and cover in permanent 1‐m2plots during 1980‐2005 in three old‐growth forests with differing tephra depths. For 26 species, we calculated the frequency of plots with residuals (individuals that survived the eruption) versus re‐establishment on the tephra, timing of establishment, turnover, influence of nearby conspecific plants, importance of three components of cover increase, and relationship of flowering frequency to succession.

Results:Tephra depth affected species behavior. Deep tephra produced fewer residuals, a greater increase in shoot size, and more shoot turnover; favored species that established late; and allowed establishment of early seral herbs. Nearby presence of conspecifics increased permanence of first establishment and rate of plot occupancy. Most species spread significantly in deep tephra but not in shallow tephra. Among species, frequency of flowering increased with fewer residuals, later establishment, and higher turnover. Species behavior seldom differed among growth forms based on leaf longevity and vegetative spread.

Conclusion:Population dynamics at the small‐plot scale differed from those of the entire population. The timing and permanency of establishment and mechanism of expansion differed among species and with tephra depth. There was some consistency among species with similar habitat breadth and degree of flowering, but little consistency associated with the usual growth form classification.
The direct regeneration hypothesis in northern forests
Authors: Ilisson Triin , Chen Han Y. H.
Published: May 2009

Question:Can the direct regeneration hypothesis (DRH) be used to predict post‐disturbance regeneration after fire, wind disturbance, and clearcutting in northern forests? Do life‐history traits such as regeneration strategy and shade tolerance influence post‐disturbance regeneration success of tree species?

Location:Northern forests in North America.

Methods:A meta‐analysis was conducted by collecting published data on pre‐ and post‐disturbance stand compositional characteristics in the northern forests. For each tree species, compositional difference (CD) was calculated as the difference between basal area proportions of the post‐ and pre‐disturbance stands, but for post‐disturbance stands <25 years of age, post‐disturbance proportions were calculated based on relative stem density.

Results:Species response to disturbances was best explained by regeneration strategy, while disturbance type had no effect on CD. The proportion of broadleaf trees with either strong or weak vegetative reproduction ability increased after all disturbances. Serotinous species had CD values not significantly different from zero after fire, while CD for semi‐serotinous species was negative. The post‐disturbance proportions of non‐serotinous conifers decreased after all forms of disturbance.

Conclusions:All disturbances promote broadleaf trees, regardless of regeneration strategy (suckering, sprouting, or seeding). The DRH is supported for conifers with serotinous cones after fire. Fire causes local extinction of non‐serotinous conifers, while wind and clearcutting only decrease the proportion of non‐serotinous conifers because of partial survival of seed sources and advanced regeneration. This study suggests that increasing stand‐replacing disturbances associated with global climate change will promote broadleaf trees in northern forests.
Experimental comparison of competition and facilitation in alpine communities varying in productivity
Authors: Onipchenko Vladimir G. , Blinnikov Mikhail S. , Gerasimova Maria A. , Volkova Elena V. , Cornelissen Johannes H.C.
Published: May 2009

Question. Competitive and facilitative interactions among plant species in different abiotic environments potentially link productivity, vegetation structure, species composition and functional diversity. We investigated these interactions among four alpine communities along an environmental productivity gradient in a generally harsh climate. We hypothesised that the importance of competition would be higher in more productive sites.

Location. Mt. M. Khatipara (43°27′N, 41°41′E, altitude 2750 m), NW Caucasus, Russia. Communities ranged from low‐productivity alpine lichen heath (ALH) and snowbed communities (SBC), to intermediate productivity Festuca grassland (FVG), and high‐productivity Geranium‐Hedysarum meadow (GHM).

Methods. We quantified the relative influence of competition and facilitation on community structure by expressing biomass of target species within each natural community proportionally to biomass of the species in a “null community” with experimental release from interspecific competition by removing all other species (for 6 years). An overall index of change in community composition due to interspecific interactions was calculated as the sum of absolute or proportional differences of the component species.

Results. Species responses to neighbour removal ranged from positive to neutral. There was no evidence of facilitation among the selected dominant species. As expected, competition was generally most important in the most productive alpine community (GHM). The intermediate position for low‐productivity communities of stressful environments (ALH, SBC) and the last position of intermediately productive FVG were unexpected.

Conclusions. Our results appear to support the Fretwell‐Oksanen hypothesis in that competition in communities of intermediate productivity was less intense than in low‐ or high‐productive communities. However, the zero net effect of competition and facilitation in FVG might be the result of abiotic stress due to strong sun exposure and high soil temperatures after neighbour removal. Thus, non‐linear relationships between soil fertility, productivity and different abiotic stresses may also determine the balance between competition and facilitation.
Political Economy of Immigration in Germany: Attitudes and Citizenship Aspirations
Authors: Kahanec Martin , Tosun Mehmet Serkan
Published: May 2009

This paper examines resident foreigners’ interest in German citizenship. We use a unique data set from a survey of foreign residents in the German states to study the roles played by factors such as attitudes towards foreigners and political interest of foreigners. We find that negative attitudes towards foreigners and generational conflict within foreigner families are significant negative factors. While interest in political participation is among the important positive factors, hostile attitudes, lack of voting rights, or uncertainty about staying in Germany mainly discourage foreigners who actively participate in the labor market, have more years of schooling, and are younger.
Benefit or Burden? Social Capital, Gender, and the Economic Adaptation of Refugees
Authors: Allen Ryan
Published: May 2009

This paper examines the role of co-ethnic social capital on the earnings of refugees, using a unique data set for adult refugees who resettled in Portland, Maine, between 1998 and 2004. Multiple regression models test the effect of access to co-ethnic social capital on the log earnings of refugees in their first and most recent years of work. Results show that over time access to co-ethnic social capital upon arrival decreased earnings for female refugees. The paper concludes with a discussion of the implications of the findings for social capital and immigration research.
Labor Market Experiences of Canadian Immigrants with Focus on Foreign Education and Experience
Authors: Buzdugan Raluca , Halli Shiva S.
Published: May 2009

Recent Canadian immigrants have increasing education levels but decreasing earnings, partly due to the devaluation of foreign education and work experience. This study uses 2002 Ethnic Diversity Survey data and examines the value attributed to foreign education for immigrants based on their duration of stay in Canada, which proves to be an important methodological distinction. Immigrants from developing countries experience the most acute devaluation. The findings outline the limitations of human capital theory in explaining the labor market experience of Canadian immigrants and have implications for the current “point system” used to select immigrants to Canada.
Integration of Childhood Immigrants in the Short and Long Run — Swedish Evidence
Authors: Böhlmark Anders
Published: May 2009

Immigrant children are often at a disadvantage at school while they adjust to their new environment. It has been found that the age at immigration of 7 or above represents a sensitive period as regards these children's school performance for two main reasons: they have passed their prime age for language learning, and their acquisition of subject skills is less efficient while they learn to master the new language. Using Swedish administrative data, we track childhood immigrants born between 1972 and 1976 over time from adolescence (at 16) to adulthood (at 30), and study the role of age at immigration for educational and labor market outcomes. We find that immigration at a sensitive age (compared to a very young age) has a strong negative impact on compulsory school performance, but that the same individuals catch up strongly in terms of final educational attainment. In spite of this educational catching up, however, we find a considerable negative impact on earnings for men. We are able to rule out two potential mechanisms behind this puzzling result: It cannot be explained either by an impact on the chosen field of study or on completion time.
The Revolving Door to Gold Mountain: How Chinese Immigrants Got around U.S. Exclusion and Replenished the Chinese American Labor Pool, 1900–1910
Authors: Chew Kenneth , Leach Mark , Liu John M.
Published: May 2009

This study provides a quantitative perspective on the Chinese American migratory system of the late 19th and early 20th centuries, including the magnitude of various means for evading the U.S. embargo on Chinese immigration. Three sources are explored, including federal immigration summaries, census microdata, and a sample of person-voyage records for steamship arrivals at the port of San Francisco (n = 5,707). Whereas parameter estimates vary among the sources from nearly twofold (gross migration) up to fourfold (net migration), all results are consistent with a revolving-door system in which young male workers arrived as replacements for departing older male workers.
Sacral osteochondrosis in two German Shepherd Dogs
Authors: Mathis KR , Havlicek M , Beck JB , Eaton‐Wells RD , Park FM
Published: May 2009

Two young adult male castrated German Shepherd Dogs were referred for evaluation of intermittent episodes of hindlimb pain. Physical examination suggested lumbosacral stenosis, and plain radiographs and computed tomography revealed lesions consistent with sacral osteochondrosis. One dog had osteochondral fragments removed surgically; the other was managed conservatively. The surgically treated dog had complete resolution of clinical signs whereas the dog managed conservatively had repeated episodes of mild pain and received one short course of non‐steroidal anti‐inflammatory medication in 18 months. Sacral osteochondrosis has not been previously reported in Australia.