bluuebunny/crossref_metadata_2025 huggingface dataset:
The Politics of Environmental Risk: Perceptions of Risk Assessment in the State Legislatures
Authors: Cohen Nevin
Published: April 2005

As state governments increasingly turn to the process of quantitative risk assessment to set environmental policy, the question of what state lawmakers know and believe about risk and the risk assessment process has become critical. The perceptions of state legislators may affect their decisions about a wide range of environmental conflicts, from funding water treatment facilities to siting hazardous waste incinerators. This article reports the results of a nationwide survey of state legislators and their staff that explored their intuitive understanding of environmental risk and risk assessment. The survey revealed strong support for the use of risk assessment by most state lawmakers, but significant differences, by gender and political affiliation, in perceptions of the risks from chemicals, the value of risk assessment for setting environmental policies, and the environmental risks faced by racial minorities.
A Resource Model of Computer‐Mediated Political Life
Authors: Wilhelm Anthony G.
Published: April 2005

Using Current Population Survey data, this paper examines the extent to which a person's resources impact his or her ability to participate in computer‐mediated political life. Resources such as universal literacy, background capacities, skills, and training clarify the well‐documented but poorly conceptualized gap in technology access between “haves” and “have nots.” Telecommunications policy does not address seriously the resources one brings to the table beyond perfunctory attention to what is affordable. Until resource disparities are examined more closely by policymakers, the divide in access to the computer‐mediated political public sphere likely will continue to expand.
Change and Continuity in the Relationship Between Private Responsibilities and Public Officeholding: The More Things Change, the More They Stay the Same
Authors: Dodson Debra L.
Published: April 2005

National surveys of state legislators conducted by the Center for the American Woman and Politics between 1977 and 1988 suggest that women's presence within state legislatures has increased despite the persistence of gender differences in the connection between public roles and private responsibilities. Mothers (but not fathers) of young children are substantially underrepresented among state legislators, and marriage continues to bring more advantage to men's than to women's political careers. Women continue to reach the legislative rung on the political ladder later than men, and women legislators are less likely than their male colleagues to hold extralegislative employment. While structural changes may reduce the incumbency advantage that some suggest have disadvantaged women, so long as gender differences in the compatibility of legislative service and private roles persist, fewer women than men at any given time will be positioned to take advantage of new opportunities, thereby making improvements in descriptive and substantive representation elusive and difficult goals to accomplish.
It Doesn't Matter: Some Cautionary Findings About Sex and Representation From School Committee Conversations
Authors: Donahue Jesse
Published: April 2005

One of the most important findings in the field of gender and politics is that women elected officials at the state and national levels do a better job than men of representing the interests of women, children, and families. This paper uses school committees to ask the same question about women elected officials at the local level. Thus the question that guides this paper is: Does it matter for women if women are elected to this local political institution? If it does matter, then we should “hear” women's distinct ways of participating through their discussions at committee meetings. The study finds, in contrast, that in this political institution women and men behave in remarkably similar ways when separated by committee roles, and that women elected officials in this political institution spend very little time addressing issues affecting girls in public education.
Salient virulence factors in anaerobic bacteria, with emphasis on their importance in endodontic infections
Authors: Olsen Ingar , Dahlén Gunnar
Published: April 2005

Endodontic infections by microbial invasion of the necrotic pulp lead to apical periodontitis of both acute and chronic forms. Acute lesions often develop from multiplication of bacteria in primary infections. Such lesions may also occur as exacerbations of chronic forms provoked for example in conjunction with endodontic treatment measures. The clinical course appears related to the character of the microflora. While primary infections are predominated by a mixed flora of anaerobic bacteria and resembles that of aggressive marginal periodontitis, chronic forms of apical periodontitis emerge following regression of the acute infection, whereupon prevailing bacteria have assumed low activity. The significance of virulence factors is easy to understand as far as acute inflammatory conditions are concerned. The role of virulence factors for sustaining chronic inflammation is more unclear and complex. This review is about salient virulence factors in some selected bacterial genera such asPeptostreptococcus, Porphyromonas, PrevotellaandFusobacterium, which often predominate the root canal microbiota in the acute phase of endodontic infections.
Gram‐positive organisms in endodontic infections
Authors: Chávez de Paz Luis
Published: April 2005

Culture‐based studies in endodontics have more or less overlooked the significance of Gram‐positive facultative bacteria in recent decades. By contrast, Gram‐negative anaerobes have been extensively studied because of their frequent recovery in primary root canal infections and their association with acute manifestations of apical periodontitis. More recent years have seen a renewed interest in Gram‐positive facultatives as these organisms are common in samples from root‐filled teeth affected by apical periodontitis. Structural components of the robust bacterial cell wall of Gram positives protect them from noxious environmental factors. Additionally, the majority of these organisms express fast‐adaptive properties when exposed to extreme conditions, thus making them potentially interesting as causal elements in post‐treatment endodontic disease. This review relates to different aspects of Gram‐positive bacteria and their adaptive responses when being exposed to stressful conditions such as endodontic treatment procedures.
From agriculture based on fossil fuel resources to agriculture based on biological interactions and matter cycling in agroecosystems
Authors: Shiyomi Masae
Published: April 2005

The modern system of agriculture, which depends on the consumption of large quantities of fossil fuel, will be forced to change to a system in which matter cycling and the various interactions operating among organisms and between organisms and their environment are effectively used. Three key factors will necessitate this change: the depletion of readily available fossil fuel resources; the leveling‐off of the growth and yield response of crops in response to the increase in the use of fertilizers, agrochemicals and big machinery; and the degradation of the environment associated with the consumption of fossil fuels and derived agrochemicals. Therefore, it is essential to further promote the following two types of study: (i) the elucidation of the structure and use of complex biological interactions, and the cause‐and‐effect relationships among and between organisms in relation to their environment; and (ii) the effective use of matter cycling in agricultural ecosystems. Efficient use of biological interactions and matter cycling will reduce the dependence of agriculture on fossil fuel.
Forage production and animal husbandry in Korea
Authors: Seo Sung
Published: April 2005

The livestock industry in Korea is primarily carries out feeding through the utilization of concentrates and rice straw. The amount of imported concentrate is estimated to be more than two thirds (about 11 million metric tons (MT) per year) of the total concentrates required, specifically corn. Recently, about 600 000 MT of forage was recorded to be imported per year. The main feature of grassland agriculture, including forage production, is the dependence on perennial grasses, legumes and high quality annual forage crops, such as corn, sorghum, sudangrass, rye, oats, barley, Italian ryegrass and forage rape, among others. In addition, proper land use and increased animal profitability is maintained through grassland agriculture.

The important fields for forage production are upland, paddy land, grassland and forest areas. Rice straw is also one of the most important roughages in Korea. The aim of forage production in the past was to fulfil the domestic need of herbivores, but forage production in 21st century is geared towards international competitiveness in animal husbandry. The most important factor is to enhance forage sufficiency related to environment‐friendly livestock in Korea. Fortunately, there are many possibilities in forage production. A no forage‐sufficiency, no food‐sufficiency; no forage, no cattle concept is emphasized.
Perspectives on the grazing system in Japan
Authors: Sato Shusuke
Published: April 2005

Cattle were first imported from the continent during the Yayoi‐style culture stage around the first and second centuries before Christ. There were no fundamental changes in the rearing structure until the ratification of the agricultural basic law of 1961 that each farmer rears one or two cows for the purposes of farming labour and manure production. The grazing system seems to have been rare until 1960s. Though the total area of grassland and the total number of cattle increased drastically after the agricultural basic law, the feed composition gradually became biased to the concentrates imported and the grazing system is still not widely used. The new agricultural basic law of 1999 aims to increase the self‐sufficiency rate of the feed and promotes to establish a ‘Japanese‐Style Grazing System’. There are five types of new suitable places for grazing in Japan. These are the redundant rice paddy field, abandoned arable land, deserted fuelwood forest, abandoned public native grassland and forest in deep mountains. The grazing technologies are nearly completed in the former two types. There are, however, a lot of endangered plants and animals and pests in the latter three types. Additionally, most of the forest is designated as conservation forest. The grazing system there should be in harmony with the conservation of and protection from wild species. It is also important to develop the automatic monitoring and collecting system for cattle and to make animals able to forage effectively and to take care of their calves properly under the free‐ranging system. As the international competitive power of Japanese agriculture is rather low, it is necessary to form a new food system consisting of the animal production, local cultivators and the consumer and the taxpayer.
Appearance and development of tillers in herbage grass species 2. Timothy (Phleum pratense L.)
Authors: Emoto Taiji , Ikeda Hajime
Published: April 2005

The persistence of timothy in grasslands was investigated in the present study. Seeds were sown in August and October 1999 and March 2000. Following transplantation in September and November 1999 and April 2000, plant length and dry matter weight of each organ were measured in every tiller every three months.

The results were obtained under the limited conditions of uninterrupted growth of timothy plants in the sward. The seasonal changes in plant lengths of the first year of establishment differed with the sowing times. In the second year, the tillers were divided into two by means of seasonal changes in plant length: some tillers increasing rapidly during the growing season from spring to late spring and the others gradually from autumn to winter. In the second year, the seasonal changes in the total tiller numbers of differing sowing times showed almost the same pattern, and secondary and tertiary tillers alternating with the main culm and primary tiller predominated. The changes in dry matter weight of each organ, especially the changes of the haplocorms, corresponded with the alternations of generations of tillers. That is, the parental tillers provided nutrients to haplocorms until the main tillers bore ears and developed. The parental tillers suppressed the appearance of tillers of the next generation to avoid competition. The tillers of the next generation began to emerge after the parental tillers died. The mechanism of the harmonious alternation of tiller generations composed of several tiller order groups was inferred to be one of the factors allowing the persistence of the timothy sward.
Isolation of disease resistance gene analogs from Italian Ryegrass (Lolium multiflorum Lam.)
Authors: Ikeda Seishi
Published: April 2005

Large‐scale sequencing of disease resistance gene analogs (RGA) in Italian ryegrass was carried out using degenerate primers and a nested polymerase chain reaction (PCR) strategy. A total of 24 000 PCR clones were subjected to single pass sequencing to enable similarity searches of public databases. As a result, 9344 clones showed significant levels of homology to either known resistance genes or RGA derived from other plant species. These clones were grouped into 115 clusters based on nucleotide sequence similarities and representative clones were selected from each cluster. Of 115 representative clones, 62 had a continuous open reading frame and were defined as potentially functional RGA from Italian ryegrass. Specific sequenced tag site (STS) primer sets were designed for these 62 clones and 50 RGA sequences were subsequently amplified from genomic DNA of Italian ryegrass in one step PCR. A subset of these STS primers could also amplify the expected size PCR products from genomic DNA of tall fescue and meadow fescue, both of which are forage crops closely relate to Italian ryegrass.
QUASIPARTICLE INTERFERENCE PATTERNS AS A TEST FOR THE NATURE OF THE PSEUDOGAP PHASE IN THE CUPRATE SUPERCONDUCTORS
Authors: PEREG-BARNEA T. , FRANZ M.
Published: April 2005

Electrons, when scattered by static random disorder, form standing waves that can be imaged using scanning tunneling microscopy. Such interference patterns, observable by the recently developed technique of Fourier transform scanning tunneling spectroscopy (FT-STS), are shown to carry unique fingerprints characteristic of the electronic order present in a material. We exploit this feature of the FT-STS technique to propose a test for the nature of the enigmatic pseudogap phase in the high-Tc cuprate superconductors. Through their sensitivity to the quasiparticle spectra and coherence factors, the FT-STS patterns, in principle, carry enough information to unambiguously determine the nature of the condensate responsible for the pseudogap phenomenon. In practice, the absence of a detailed understanding of the scattering mechanism, together with the experimental uncertainties, prevent such an unambiguous determination. We argue, however, that the next generation of FT-STS experiments, currently underway, should be able to distinguish between the pseudogap dominated by the remnants of superconducting order from the pseudogap dominated by some competing order in the particle-hole channel. Using general arguments and detailed numerical calculations, we point to certain fundamental differences between the two scenarios and discuss the prospects for future experiments.
Angiostatin is negatively associated with coronary collateral growth in patients with coronary artery disease
Authors: Matsunaga Toshiro , Chilian William M. , March Keith
Published: April 2005

Angiostatin, an inhibitor of tumor angiogenesis, is produced by the actions of matrix metalloproteinases (MMP) on plasminogen. Recently, we reported that angiostatin levels are increased in a model of inadequate coronary collateral growth and angiogenesis in response to ischemia, despite high levels of vascular endothelial growth factor (VEGF). We hypothesized that angiostatin levels are negatively associated with collateral formation in patients. Coronary angiograms from 37 patients undergoing coronary bypass surgery were evaluated for the absence of angiographically visible collaterals (Rentrop scores of 0) or the presence of Rentrop classification grade 3 (well developed) collaterals. Pericardial fluid was obtained from each patient during the bypass procedure, and the sample was analyzed for angiostatin, plasminogen, and VEGF (Western analysis) and for combined activities of MMP-2 and MMP-9 (zymographic analysis). In patients with no collaterals, angiostatin level was greater compared with that in patients with well-developed collaterals (3.1 ± 0.2 vs. 2.3 ± 0.1 optical density units, P < 0.05). Neither MMP activities nor VEGF levels were different between the two groups of patients. The higher levels of angiostatin in patients with no visible collaterals were reflective of a higher concentration of plasmin/plasminogen (6.2 ± 0.7 vs. 4.2 ± 0.5 optical density units, P < 0.05) compared with those in patients with well-developed collateral vessels. Our results support the concept that the growth inhibitor angiostatin may have a negative impact on coronary collateral growth in patients. Perhaps therapies attempting to provoke coronary collateral growth should incorporate approaches to limit or neutralize the effects of growth inhibitors.
Increased expression of bradykinin type-1 receptors in endothelium of intramyocardial coronary vessels in human failing hearts
Authors: Liesmaa Inka , Kuoppala Antti , Shiota Naotaka , Kokkonen Jorma O. , Kostner Karam , Mäyränpää Mikko , Kovanen Petri T. , Lindstedt Ken A.
Published: April 2005

In experimental animals, bradykinin type-1 receptors (BK-1Rs) are induced during inflammation and ischemia, and, by exerting either cardioprotective or cardiotoxic effects, they may contribute to the pathogenesis of heart failure. Nothing is known about the expression of BK-1Rs in human heart failure. Human heart tissue was obtained from excised hearts of patients undergoing cardiac transplantation ( n = 13), due to idiopathic dilated cardiomyopathy (IDC; n = 7) or to coronary heart disease (CHD; n = 6), and from normal hearts ( n = 6). The expression of BK-1Rs was analyzed by means of competitive RT-PCR, Western blot analysis, and immunohistochemistry. Expression of BK-1R mRNA was increased in both IDC (2.8-fold) and CHD (2.1-fold) hearts compared with normal hearts. The observed changes were verified at the protein level. Expression of BK-1Rs in failing hearts localized to the endothelium of intramyocardial coronary vessels and correlated with an increased expression of TNF-α in the vessel wall. Treatment of human coronary artery endothelial cells with TNF-α increases their BK-1R expression. These novel results show that BK-1Rs are induced in the endothelium of intramyocardial coronary vessels in failing human hearts and so may participate in the pathogenesis of heart failure.
COX-2 inhibition prevents downregulation of key renal water and sodium transport proteins in response to bilateral ureteral obstruction
Authors: Nørregaard Rikke , Jensen Boye L. , Li Chunling , Wang Weidong , Knepper Mark A. , Nielsen Søren , Frøkiær Jørgen
Published: April 2005

Bilateral ureteral obstruction (BUO) is associated with marked changes in the expression of renal aquaporins (AQPs) and sodium transport proteins. To examine the role of prostaglandin in this response, we investigated whether 24-h BUO changed the expression of cyclooxygenases (COX-1 and -2) in the kidney and tested the effect of the selective COX-2 inhibitor parecoxib (5 mg·kg−1·day−1via osmotic minipumps) on AQPs and sodium transport. Sham and BUO kidneys were analyzed by semiquantitative immunoblotting, and a subset of kidneys was perfusion fixed for immunocytochemistry. BUO caused a significant 14-fold induction of inner medullary COX-2 (14.40 ± 1.8 vs. 1.0 ± 0.4, n = 6; P < 0.0001) and a reduction in medullary tissue osmolality, whereas COX-1 did not change. Immunohistochemistry confirmed increased COX-2 labeling associated with medullary interstitial cells. COX isoforms did not change in cortex/outer medulla after 24-h BUO. In BUO kidneys, inner medullary AQP2 expression was reduced, and this decrease was prevented by parecoxib. In the inner stripe of outer medulla, the type 3 Na+/H+exchanger (NHE3) and apical Na+-K+-2Cl−cotransporter (BSC-1) were significantly reduced by BUO, and this decrease was significantly attenuated by parecoxib. Immunohistochemistry for AQP2, NHE3, and BSC-1 confirmed the effect of parecoxib. Parecoxib had no significant effect on the Na-K-ATPase α1-subunit, type II Na-Picotransporter, or AQP3. In conclusion, acute BUO leads to marked upregulation of COX-2 in inner medulla and selective COX-2 inhibition prevents dysregulation of AQP2, BSC-1, and NHE3 in response to BUO. These data indicate that COX-2 may be an important factor contributing to the impaired renal water and sodium handling in response to BUO.
Baroreflex Failure
Authors: Heusser Karsten , Tank Jens , Luft Friedrich C. , Jordan Jens
Published: April 2005

The baroreflex receives less attention nowadays because most students of hypertension are convinced that faulty volume regulation by the kidneys is responsible for long-term blood pressure increases. However, unusual patients with bilateral destruction of the normal blood pressure–sensing mechanisms can develop profound chronic hypertension. We present 2 patients with baroreflex failure. Both had volatile hypertension with systolic readings up to 300 mm Hg documented over years. Both had muscle sympathetic nerve activity that was increased even while resting. Treating these patients was a stochastic challenge. The therapy is frequently based on medicines that are no longer commonly prescribed.
Antioxidant Treatment Prevents Renal Damage and Dysfunction and Reduces Arterial Pressure in Salt-Sensitive Hypertension
Authors: Tian Niu , Thrasher Kristina D. , Gundy Paul D. , Hughson Michael D. , Manning R. Davis
Published: April 2005

The goal of this study was to test the hypothesis that oxidative stress in Dahl salt-sensitive (SS) rats on a high-sodium intake contributes to the progression of renal damage, the decreases in renal hemodynamics, and the development of hypertension. We specifically studied whether antioxidant therapy, using vitamins C and E, could help prevent renal damage and glomerular filtration rate (GFR) and renal plasma flow reductions and attenuate the increases in arterial pressure. Thirty-three 7- to 8-week old Dahl SS/Rapp strain rats were placed on either a high-sodium (8%) or a low-sodium (0.3%) diet with or without vitamin E (111 IU/d) in the food and 98 mg/d vitamin C in the drinking water for 5 weeks. Rats were equipped with indwelling arterial and venous catheters at day 21. By day 35 in the rats with high-sodium diet, vitamin C and E treatment significantly decreased renal cortical and medullary O
2
·−
release, mean arterial pressure, urinary protein excretion, glomerular necrosis, and renal tubulointerstitial damage. At this time, GFR significantly decreased in the high-sodium diet group (1.6±0.2 mL/min) when compared with either the high-sodium plus vitamins C and E (2.9±0.2 mL/min) or the low-sodium diet group (2.9±0.3 mL/min). In SS rats on high-sodium diet, renal plasma flow decreased 40%, and this reduced flow was restored by vitamin treatment. In Dahl salt-sensitive hypertension, increased oxidative stress plays an important role in the renal damage, decreases in renal hemodynamics, and increases in arterial pressure that occur. Antioxidant treatment with vitamins C and E improves renal dysfunction, lessens renal injury, and decreases arterial pressure in Dahl salt-sensitive hypertension.
Aldosterone Receptor Blockade Prevents the Transition to Cardiac Pump Dysfunction Induced by β-Adrenoreceptor Activation
Authors: Veliotes Demetri G.A. , Woodiwiss Angela J. , Deftereos Dawn A.J. , Gray David , Osadchii Oleg , Norton Gavin R.
Published: April 2005

The transition from compensated to decompensated left ventricular hypertrophy (LVH) in hypertension involves excessive β-adrenoreceptor (β-AR) stimulation. To explore whether aldosterone receptor activation contributes toward β-AR–induced left ventricular (LV) decompensation in hypertensive LVH, the effect of spironolactone (SPIRO; 80 mg · kg
−1
· day
−1
) on LV cavity dimensions, function, and chamber remodeling mechanisms was evaluated in spontaneously hypertensive rats (SHR) receiving a low dose of the β-AR agonist isoproterenol (ISO) at 0.02 to 0.04 mg · kg
−1
· day for 4.5 months. ISO administered to SHR resulted in an increased 24-hour urinary aldosterone excretion and LV cavity dimensions, a right shift in LV diastolic pressure-volume relations, a decreased LV relative wall thickness, and increased total, noncross-linked, type I and type III myocardial collagen concentrations without further enhancing increased myocardial norepinephrine (NE) release. ISO reduced pump function without modifying intrinsic myocardial systolic function or inducing further myocyte necrosis or apoptosis. ISO only increased LV cavity volumes after prolonged periods of administration. SPIRO abolished ISO-induced chamber dilatation, wall thinning, and pump dysfunction and reduced total, noncross-linked, type I and type III myocardial collagen concentrations but failed to modify blood pressure, volume preloads, intrinsic myocardial systolic function, myocardial NE release, or the degree of necrosis or apoptosis. In conclusion, these results suggest that aldosterone receptor blockade, through load-independent effects, may be useful in preventing the transition from compensated LVH to dilatation and pump dysfunction mediated by chronic β-AR activation.
Involvement of RhoA/Rho Kinase Pathway in Myogenic Tone in the Rabbit Facial Vein
Authors: Dubroca Caroline , You Dong , Lévy Bernard I. , Loufrani Laurent , Henrion Daniel
Published: April 2005

Myogenic tone (MT), a fundamental stretch-sensitive vasoconstrictor property of resistance arteries and veins, is a key determinant of local blood flow regulation. We evaluated the pathways involved in MT development. The role of the RhoA/Rho kinase, p38 MAP kinase, and HSP27 in MT was investigated in the rabbit facial vein (RFV), previously shown to possess MT at a pressure level equivalent to 20 mm Hg. Venous MT is poorly understood, although venous diseases affect a large proportion of the population. Stretched RFV are characterized by a temperature-sensitive MT, which is normal at 39°C but fails to develop at 33°C. This allows for the discrimination of the pathways involved in MT from the multiple pathways activated by stretch. Isolated RFV segments were mounted in organ baths and stretched. Temperature was then set at 33°C or 39°C. MT was associated to the translocation of RhoA to the plasma membrane and the Rho kinase inhibitor Y27632 decreased stretch-induced MT by 93.1±4.9%. MT was also associated to an increase in p38 (131.0±12.5% at 39°C versus 100% at 33°C) and HSP27 phosphorylation (196.1±13.3% versus 100%), and the p38 MAP kinase inhibitor SB203580 decreased MT by 36.5±8.1%. (39°C, compared with RFV stretched at 33°C). Finally, phosphorylation of p38 was blocked by Y27632 and HSP27 phosphorylation was inhibited by SB203580 and Y27632. Thus, MT and the associated p38 and HSP27 phosphorylation seem to depend on RhoA/Rho kinase activation in stretch RFV.
Muscle Fiber-Type Distribution as a Predictor of Blood Pressure
Authors: Hernelahti Miika , Tikkanen Heikki O. , Karjalainen Jouko , Kujala Urho M.
Published: April 2005

The known association between physical activity and low blood pressure may be influenced by inherited characteristics. Skeletal muscle consists of type I (slow-twitch) and type II (fast-twitch) muscle fibers, with proportions highly variable between individuals and mostly determined by genetic factors. A high percentage of type I fibers (type I%) has been associated with low blood pressure in cross-sectional studies. We investigated whether type I percentage predicts future blood pressure levels and explains part of the association between physical activity and blood pressure. At baseline, in 1984, muscle fiber-type distribution, physical activity, and body mass index (BMI) were determined in 64 healthy men (age, 32 to 58 years). At follow-up, in 2003, blood pressure, physical activity, and BMI were determined in these men. In subjects without antihypertensive medication (n=43), type I percentage accounted for 5%/18% of the variation in systolic/diastolic blood pressure. A high type I percentage predicted, independent of both baseline (in 1984) and follow-up (in 2003), physical activity, BMI, and low systolic and diastolic blood pressure. Adjusted for all baseline covariates, a 20-unit higher type I percentage predicted a 11.6-mm Hg lower systolic blood pressure (
P
=0.018) and a 5.0-mm Hg lower diastolic blood pressure (
P
=0.018). High levels of physical activity in 1984 predicted low diastolic blood pressure, but this association was lost when type I percentage was included into the model. A high proportion of type I fibers in skeletal muscle is an independent predictor of low blood pressure and explains part of the known association between high levels of physical activity and low blood pressure.
Aortic Pressure Augmentation Predicts Adverse Cardiovascular Events in Patients With Established Coronary Artery Disease
Authors: Chirinos Julio A. , Zambrano Juan P. , Chakko Simon , Veerani Anila , Schob Alan , Willens Howard J. , Perez Guido , Mendez Armando J.
Published: April 2005

Pulse pressure (PP), a marker of arterial stiffness, predicts cardiovascular risk. We aimed to determine whether augmentation pressure (AP) derived from the aortic pressure waveform predicts major adverse cardiovascular events (MACE) and death independently of PP in patients with established coronary artery disease (CAD). We prospectively followed-up 297 males undergoing coronary angiography for 1186±424 days. Ascending aortic pressure tracings obtained during catheterization were used to calculate AP (difference between the second and the first systolic peak). Augmentation index (AIx) was defined as AP as a percentage of PP. We evaluated whether AP and AIx can predict the risk of MACE (unstable angina, acute myocardial infarction, coronary revascularization, stroke, or death) and death using Cox regression. All models evaluating AP included PP to assess whether AP adds to the information already provided by PP. Both AP and AIx significantly predicted MACE. The hazard ratio (HR) per 10 mm Hg increase in AP was 1.20 (95% confidence interval [CI], 1.08 to 1.34;
P
<0.001); the HR for each 10% increase in AIx was 1.28 (95% CI, 1.11 to 1.48;
P
=0.004). After adjusting for other univariate predictors of MACE, age, and other potential confounders, AP remained a significant predictor of MACE (HR per 10 mm Hg increase=1.19; 95% CI, 1.06 to 1.34;
P
=0.002), as did AIx (adjusted HR, 1.28; 95% CI, 1.09 to 1.50;
P
=0.003). AP was a significant predictor of death (HR per 10 mm Hg increase=1.18; 95% CI, 1.02 to 1.39;
P
=0.03). Higher AIx was associated with a trend toward increased mortality (HR=1.22; 95% CI, 0.98 to 1.52;
P
=0.056). Aortic AP predicts adverse outcomes in patients with CAD independently of PP and other risk markers.
Génesis y desarrollo de las actitudes lingüísticas en contextos bilingües. Análisis de algunas variables del ámbito escolar y sociofamiliar
Authors: Huguet-Canalís Ángel
Published: April 2005

Situados en los contextos bilingües asturiano y aragonés, y dadas las relaciones existentes entre actitudes generadas ante una determinada lengua y el nivel de competencia adquirido en la misma, el objetivo de nuestra investigación es doble: por una parte se pretende describir las actitudes ante las lenguas en presencia (asturiano y castellano en Asturias, y catalán y castellano en el Este de Aragón) y, por otra, estudiar las variables que pueden explicar su desarrollo.

Para ello se adaptó un cuestionario de actitudes que había sido utilizado con éxito en otros ámbitos y se aplicó a una muestra de 231 escolares en el Principado de Asturias y de 163 escolares en Aragón, todos ellos en 2° curso de Educación Secundaria (ESO).

Globalmente, en cada caso, los resultados evidencian unas actitudes favorables a las lenguas en presencia, pero éstas vienen determinadas por una influencia significativa de la asistencia o no a clases de asturiano en Asturias o de catalán en Aragón y, también, de la condición lingüística familiar de los sujetos.
Filtering high-throughput protein-protein interaction data using a combination of genomic features
Authors: Patil Ashwini , Nakamura Haruki
Published: April 2005

Background

Protein-protein interaction data used in the creation or prediction of molecular networks is usually obtained from large scale or high-throughput experiments. This experimental data is liable to contain a large number of spurious interactions. Hence, there is a need to validate the interactions and filter out the incorrect data before using them in prediction studies.

Results

In this study, we use a combination of 3 genomic features – structurally known interacting Pfam domains, Gene Ontology annotations and sequence homology – as a means to assign reliability to the protein-protein interactions in Saccharomyces cerevisiae determined by high-throughput experiments. Using Bayesian network approaches, we show that protein-protein interactions from high-throughput data supported by one or more genomic features have a higher likelihood ratio and hence are more likely to be real interactions. Our method has a high sensitivity (90%) and good specificity (63%). We show that 56% of the interactions from high-throughput experiments in Saccharomyces cerevisiae have high reliability. We use the method to estimate the number of true interactions in the high-throughput protein-protein interaction data sets in Caenorhabditis elegans, Drosophila melanogaster and Homo sapiens to be 27%, 18% and 68% respectively. Our results are available for searching and downloading at http://helix.protein.osaka-u.ac.jp/htp/.

Conclusion

A combination of genomic features that include sequence, structure and annotation information is a good predictor of true interactions in large and noisy high-throughput data sets. The method has a very high sensitivity and good specificity and can be used to assign a likelihood ratio, corresponding to the reliability, to each interaction.
Mitochondrial haplotype diversity in the tortoise species Testudo graeca from North Africa and the Middle East
Authors: van der Kuyl Antoinette C , Ballasina Donato LP , Zorgdrager Fokla
Published: April 2005

Background

To help conservation programs of the endangered spur-thighed tortoise and to gain better insight into its systematics, genetic variation and evolution in the tortoise species Testudo graeca (Testudines: Testudinidae) was investigated by sequence analysis of a 394-nucleotide fragment of the mitochondrial 12S rRNA gene for 158 tortoise specimens belonging to the subspecies Testudo graeca graeca, Testudo graeca ibera, Testudo graeca terrestris, and a newly recognized subspecies Testudo graeca whitei. A 411-nucleotide fragment of the mitochondrial D-loop was additionally sequenced for a subset of 22 T. graeca, chosen because of their 12S gene haplotype and/or geographical origin.

Results

Haplotype networks generated by maximum-likelihood and neighbor-joining analyses of both the separate and the combined sequence data sets suggested the existence of two main clades of Testudo graeca, comprising Testudo graeca from northern Africa and Testudo graeca from the Turkey and the Middle East, respectively.

Conclusion

Mitochondrial DNA haplotyping suggests that the tortoise subspecies of T. g. graeca and T. g. ibera are genetically distinct, with a calculated divergence time in the early or middle Pleistocene. Other proposed subspecies could not clearly be recognized based upon their mt haplotypes and phylogenetic position, and were either part of the T. g. graeca or of the T. g. ibera clade, suggesting that genetic evidence for the existence of most of the 15 proposed subspecies of T. graeca is weak.
Molecular phylogeny and evolution of alcohol dehydrogenase (Adh) genes in legumes
Authors: Fukuda Tatsuya , Yokoyama Jun , Nakamura Toru , Song In-Ja , Ito Takuro , Ochiai Toshinori , Kanno Akira , Kameya Toshiaki , Maki Masayuki
Published: April 2005

Background

Nuclear genes determine the vast range of phenotypes that are responsible for the adaptive abilities of organisms in nature. Nevertheless, the evolutionary processes that generate the structures and functions of nuclear genes are only now be coming understood. The aim of our study is to isolate the alcohol dehydrogenase (Adh) genes in two distantly related legumes, and use these sequences to examine the molecular evolutionary history of this nuclear gene.

Results

We isolated the expressed Adh genes from two species of legumes, Sophora flavescens Ait. and Wisteria floribunda DC., by a RT-PCR based approach and found a new Adh locus in addition to homologues of the Adh genes found previously in legumes. To examine the evolution of these genes, we compared the species and gene trees and found gene duplication of the Adh loci in the legumes occurred as an ancient event.

Conclusion

This is the first report revealing that some legume species have at least two Adh gene loci belonging to separate clades. Phylogenetic analyses suggest that these genes resulted from relatively ancient duplication events.
Contextualizing and assessing the social capital of seniors in congregate housing residences: study design and methods
Authors: Moore Spencer , Shiell Alan , Haines Valerie , Riley Therese , Collier Carrie
Published: April 2005

Background

This article discusses the study design and methods used to contextualize and assess the social capital of seniors living in congregate housing residences in Calgary, Alberta. The project is being funded as a pilot project under the Institute of Aging, Canadian Institutes for Health Research.

Design/Methods

Working with seniors living in 5 congregate housing residencies in Calgary, the project uses a mixed method approach to develop grounded measures of the social capital of seniors. The project integrates both qualitative and quantitative methods in a 3-phase research design: 1) qualitative, 2) quantitative, and 3) qualitative. Phase 1 uses gender-specific focus groups; phase 2 involves the administration of individual surveys that include a social network module; and phase 3 uses anamolous-case interviews. Not only does the study design allow us to develop grounded measures of social capital but it also permits us to test how well the three methods work separately, and how well they fit together to achieve project goals.

This article describes the selection of the study population, the multiple methods used in the research and a brief discussion of our conceptualization and measurement of social capital.
Wanted, an Anthrax vaccine: Dead or Alive?
Authors: Smith Kendall A
Published: April 2005

It has been more than 100 years since the realization that microbes are capable of causing disease. In that time, we have learned a great deal as to how each organism has adapted to the immune system so as to avoid elimination. As well, we have also learned an immense amount since Louis Pasteur first proposed that the solution to infectious diseases was to culture the microbes and attenuate their virulence, so as to use them as vaccines. From the optimism and promise of the 19thcentury and immunization as the ultimate answer to the invasion by the microbial world, to the scientific realities of the 21stcentury, it is of interest to retrace the steps of the earliest microbiologists cum immunologists, to realize how far we've come, as well as how far we yet have to go. This editorial focuses on the history of anthrax as a microbial disease, and the earliest efforts at producing a vaccine for its prevention.
Amphotropic murine leukaemia virus envelope protein is associated with cholesterol-rich microdomains
Authors: Beer Christiane , Pedersen Lene , Wirth Manfred
Published: April 2005

Background

Cholesterol-rich microdomains like lipid rafts were recently identified as regions within the plasma membrane, which play an important role in the assembly and budding of different viruses, e.g., measles virus and human immunodeficiency virus. For these viruses association of newly synthesized viral proteins with lipid rafts has been shown.

Results

Here we provide evidence for the association of the envelope protein (Env) of the 4070A isolate of amphotropic murine leukaemia virus (A-MLV) with lipid rafts. Using density gradient centrifugation and immunocytochemical analyses, we show that Env co-localizes with cholesterol, ganglioside GM1 and caveolin-1 in these specific regions of the plasma membrane.

Conclusions

These results show that a large amount of A-MLV Env is associated with lipid rafts and suggest that cholesterol-rich microdomains are used as portals for the exit of A-MLV.
Holocene forest dynamics in northwestern Romnania
Authors: Feurdean Angelica
Published: April 2005

Pollen analyses and AMS radiocarbon measurements were carried out on peat deposits from the former crater lake Preluca Tiganului, located in a mid-altitude area of the Gutaiului Mountains (NW Romania), in order to reconstruct the postglacial vegetation history. At the Lateglacial/Holocene transition the open vegetation was replaced by forest, suggesting a fast response to climatic warming. The rapid expansion of Pinus, Betula and later Picea may be due to their existence in the area during the Lateglacial. At approximately 11 250 cal. yr BP, the dense forest was composed primarily of Ulmus and some Picea, Betula and Pinus. A small population of Ulmus might also have survived in the area during the Lateglacial. At 10750 cal. yr BP, Quercus, Tilia and Fraxinus, followed by Corylus at c. 10200 cal. yr BP, expanded significantly in the forest. The delay of approximately 550 years in their establishment, as compared to the expansion of Ulmus, was probably due to their immigration from more distant localities. Between 9300 and 5750 cal. yr BP, the forest became denser and was composed of Corylus (dominating), Ulmus, Quercus, Tilia, Fraxinus and Picea. At 5750 cal. yr BP Carpinus became established and expanded, possibly as a response to higher temperatures. At 5200 cal. yr BP, Fagus became locally established, and expanded from about 4800 cal. yr BP, possibly as a result of moist climatic conditions, although human activities cannot be excluded. From 4000 cal. yr BP to the present, Fagus dominated the woodlands, and all other deciduous trees (except for Carpinus and Quercus) became greatly reduced. Evidence of human influence on the local vegetation is low for this time period, but becomes more evident in the pollen stratigraphy around 2300 cal. yr BP. This is reflected by a decrease in forest diversity and an increase in pasture and forest grazing.
Influence of loss of gradient from postglacial uplift on Red River flood hazard, Manitoba, Canada
Authors: Brooks Gregory R. , Thorleifsonl L. Harvey , Lewis C. F. Michael
Published: April 2005

The north-flowing, low-gradient section of the Red River in Manitoba has lost-60%/o of its valley gradient since 8 ka cal. BP. An existing hydraulic model of the modem Red River flood zone was used to examine the change in flood extent and depth of a discharge equivalent to the 1997 Red River flood (3970 m3/s) for scenarios of gradients at 8, 6, 4 and 2 ka cal. BP as well as 2 ka in the future. The modelling indicates a broad, shallow flood zone for all of the gradient scenarios, with extent and depth increasing over time. Between the 8 ka cal. BP and present-day scenarios, the flood zone increased from 1186 km2 to 1531 km2 (-29%/o) with depth increasing along four east-west cross-sections by 0.69 m (-61%), 0.91 m (-82%), 0.56 m (-64%) and 0.48 m (-86%). The flood extent and depths increased by a further 18 km2 (--5%) and 0.04-0.06 m (2-5%), respectively, by 2 ka in the future. Most of these changes to the flood zone occurred between 8 and 2 ka cal. BP, reflecting an exponential loss of gradient. A rise in flood depth equivalent to that which occurred between 8 ka cal. BP and the present-day, is assessed as increasing the long-term flood hazard; in contrast, the slight rise in depth between the present-day and 2 ka in the future does not.
Archaeological and environmental investigations of a Lateglacial and Holocene river sedimentary sequence on the River Soar at Croft, Leicestershire, UK
Authors: Smith David N. , Roseff Rebecca , Bevan Lynne , Brown Anthony G. , Butler Simon , Hughes Gwylim , Monckton Angela
Published: April 2005

The sediments, stratigraphy and archaeology of several sections through Lateglacial and Holocene deposits associated with the past course of the Thurlston Brook at Croft, Leicestershire, UK are outlined. The results of pollen, plant macrofossil and insect analyses from these deposits are presented and this information is used to provide a detailed reconstruction of changing river conditions and human land use at this location during the Holocene. Despite the presence of hiatuses in the record seen at Croft, and other sites of this scale, with accurate work and clear dating controls it is possible to 'stitch' together continuous detailed sequences. The general pattern of Holocene landscape and fluvial change appears to echo that seen in the Trent valley region and nationally. It is suggested that small headwater catchments such as at Croft have the potential to provide detailed and sensitive records of Holocene events comparable with those from 'standard' sediment sequences.
Reconstructing rainfall and land-use conditions leading to the development of old gullies
Authors: Vanwalleghem T. , Poesen J. , Van Den Eeckhaut M. , Nachtergaelel J. , Deckers J.
Published: April 2005

Knowledge of past erosion events and their controlling factors is an important key to understanding the impacts of environmental change (climate-land use) on the landscape. In this study, knowledge about erosion processes on the development of present-day ephemeral gullies is used for reconstructing conditions leading to the formation of old, permanent gullies. Empirical relations between flow hydraulics and channel geometry have been recently established for gullies. Hence, using measured bottom width Wbttom of old gullies as input, peak flow discharges (Qp) of these gullies can be estimated. In two forested areas in central Belgium, 52 old gullies were mapped. The old gullies had an average Wbottom ranging between 1.1 and 1.5 m. Corresponding calculated Qp values ranged between 0.04 and 0.07 m3/s. Rainfall intensities (I) were also deduced from Qp using the rational formula. By simulating various land use scenarios and thus various runoff coefficient (C) values, I and concentration time (Tc) could be calculated for each land-use class. Using I, Tc and intensity-duration-frequency tables for the study area, the recurrence interval (RI) of the rain events, needed to erode the observed gully channels was assessed. Although analysis of historical documents indicates that both areas have probably been under forest since the Middle Ages, it is unlikely that the old gullies originated under forest vegetation or even degraded forest vegetation, since R>I 200 years were obtained for these land-use scenarios. Cropland is the only land use that provides acceptable values of RI(11-128 years).