bluuebunny/crossref_metadata_2025_split huggingface dataset:
Irrigation and fisheries: irreconcilable conflicts or potential synergies?
Authors: Nguyen‐Khoa S. , Smith L. E. D. 
Published: May 2004

AbstractIn situations of water scarcity, significant conflicts can arise between management of water for irrigation and inland fisheries. This paper considers the principles and lessons that can be drawn from the application of a conflict resolution mechanism—a protocol for participatory impact assessment and management—to a situation of conflict in the dry zone of Sri Lanka. Key features of this protocol are: (i) genuine participation of stakeholders; (ii) integrated assessment and management of impacts of irrigation on fisheries; (iii) management of information and an informed decision‐making process; and (iv) adoption of an iterative and learning approach. The two main sources of conflict between fishermen and irrigators in the case investigated arise in the management of reservoir water levels and in the disposal of drainage flows into coastal lagoons. Application of the protocol demonstrated ways to improve information and communication between parties, to reduce conflict and to improve resource management. Consensus for resource management options was found in emphasising the priority needs of the poorest sections of local communities, and in seeking means to improve management of irrigation to the benefit of both farmers and fishermen. Application of the protocol thus identified possible synergies between irrigation and fisheries where previously these activities had been viewed as purely antagonistic. Copyright © 2004 John Wiley & Sons, Ltd.
Impact of biological clogging agents on filter and emitter discharge characteristics of microirrigation systems
Authors: DehghaniSanij Hossein , Yamamoto Tahei , Rasiah Velu , Utsunomiya Jun , Inoue Mitsuhiro 
Published: May 2004

AbstractWater application efficiency of microirrigation systems (MIS) may depend, at least partially, on algae and protozoa (biological clogging agents, BCAs) induced filter and emitter clogging. In this study we assessed the impact of BCA‐induced changes on water discharge rate and distribution uniformity from (i) emitters with different water flow cross‐section (CS) area, pressure compensation (PC) systems, and inbuilt filtration areas (FAs), and (ii) filters either made of urethane, sand, or disk in the Tohaku irrigation project in Japan. In a field experiment, four types of on‐line emitters on each of four laterals and four types of in‐line emitters on each of another four laterals were assessed for BCA‐induced emitter discharge performance without using filters in the field irrigation line. The emitters' discharge rate increased with increasing CS, FA, and working pressure (WP) and decreased when the emitters were on‐line in the laterals and with increasing BCA counts. Because BCAs are the only dynamic variable in the above relationship, we conclude that BCA‐induced clogging is a major issue when filters were not installed in field irrigation lines. The filter performance assessment based on the number of backwashings required to restore the working pressure to the recommended level indicated that BCA filtering by the sand filter was highest, followed by disk and urethane, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
Basis set effects on calculated geometries: 6‐311++G** vs. aug‐cc‐pVDZ
Authors: Wiberg Kenneth B. 
Published: May 2004

AbstractThe effect of basis sets on MP2 and CCSD calculated geometries has been investigated for a series of small organic molecules with two to four nonhydrogen atoms. Whereas 6‐311++G** usually leads to satisfactory structures, this was not true with aug‐cc‐pVDZ, although it uses more basis functions than the former set. In addition, the smaller 6‐311++G** invariably leads to lower calculated energies than aug‐cc‐pVDZ. With a given basis set, CCSD gives more satisfactory calculated geometries than MP2, but with a much greater computation time. For the compounds in this report, B3LYP/6‐311++G** is quite effective in giving satisfactory calculated geometries at a relatively small computational cost. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1342–1346, 2004
Electrostatic potentials and fields from density expansions of deformed atoms in molecules
Authors: Rico J. Fernández , López R. , Ema I. , Ramírez G. 
Published: May 2004

AbstractThe exact representation of the molecular density by means of atomic expansions, consisting in spherical harmonics times analytical radial factors, is employed for the calculation of electrostatic potentials, fields, and forces. The resulting procedure is equivalent to an atomic multipolar expansion in the long‐range regions, but works with similar efficiency and accuracy in the short‐range region, where multipolar expansions are not valid. The performances of this procedure are tested on the calculation of the electrostatic potential contour maps and electrostatic field flux lines of water and nitrobenzene, computed from high‐quality molecular electron densities obtained with Slater basis sets. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1347–1354, 2004
Analytical method for the representation of atoms‐in‐molecules densities
Authors: Rico J. Fernández , López R. , Ramírez G. , Ema I. , Ludeña E. V. 
Published: May 2004

AbstractWe present analytic refinements and applications of the deformed atomic densities method [Fernández Rico, J.; López, R.; Ramírez, G. J Chem Phys 1999, 110, 4213–4220]. In this method the molecular electron density is partitioned into atomic contributions, using a minimal deformation criterion for every two‐center distributions, and the atomic contributions are expanded in spherical harmonics times radial factors. Recurrence relations are introduced for the partition of the two‐center distributions, and the final radial factors are expressed in terms of exponential functions multiplied by polynomials. Algorithms for the practical implementation are developed and tested, showing excellent performances. The usefulness of the present approach is illustrated by examining its ability to describe the deformation of atoms in different molecular environments and the relationship between these atomic densities and some chemical properties of molecules. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1355–1363, 2004
Microtubule disassembly induces cytoskeletal remodeling and lung vascular barrier dysfunction: Role of Rho‐dependent mechanisms
Authors: Birukova Anna A. , Smurova Ksenya , Birukov Konstantin G. , Usatyuk Peter , Liu Feng , Kaibuchi Kozo , Ricks‐Cord Anila , Natarajan Viswanathan , Alieva Irina , Garcia Joe G.N. , Verin Alexander D. 
Published: May 2004

AbstractBarrier dysfunction of pulmonary endothelial monolayer is associated with dramatic cytoskeletal reorganization, activation of actomyosin contractility, and gap formation. The linkage between the microtubule (MT) network and the contractile cytoskeleton has not been fully explored, however, clinical observations suggest that intravenous administration of anti‐cancer drugs and MT inhibitors (such as the vinca alkaloids) can lead to the sudden development of pulmonary edema in breast cancer patients. In this study, we investigated the crosstalk between MT and actomyosin cytoskeleton and characterized specific molecular mechanisms of endothelial cells (EC) barrier dysfunction induced by MT inhibitor nocodazole (ND). Our results demonstrate that MT disassembly by ND induced rapid decreases in transendothelial electrical resistance (TER) and actin cytoskeletal remodeling, indicating EC barrier dysfunction. These effects involved ND‐induced activation of Rho GTPase. Rho‐mediated activation of its downstream target, Rho‐kinase, induced phosphorylation of Rho‐kinase effector EC MLC phosphatase (MYPT1) at Thr696 and Thr850 resulting in MYPT1 inactivation. Phosphatase inhibition leaded to accumulation of diphospho‐MLC, which induced acto‐myosin polymerization, stress fiber formation and gap formation. Inhibition of Rho‐kinase by Y27632 abolished ND‐induced MYPT1 phosphorylation, MLC phosphorylation, and stress fiber formation. In addition, MT preservation via the MT stabilizer paclitaxel, Rho inhibition (via C3 exotoxin, or dominant negative (DN)‐Rho, or DN‐Rho‐kinase) attenuated ND‐induced TER decreases, stress fiber formation and MLC phosphorylation. Collectively, our results demonstrate a leading role for Rho‐dependent mechanisms in crosstalk between the MT and actomyosin cytoskeleton, and suggest Rho‐kinase and MYPT1 as major Rho effectors mediating pulmonary EC barrier disruption in response to ND‐induced MT disassembly. J. Cell. Physiol. 201: 55–70, 2004. © 2004 Wiley‐Liss, Inc.
Chromatin remodeling and stem cell theory of relativity
Authors: Cerny Jan , Quesenberry Peter J. 
Published: May 2004

AbstractThe field of stem cell biology is currently being redefined. Stem cell (hematopoietic and non‐hematopoietic) differentiation has been considered hierarchical in nature, but recent data suggest that there is no progenitor/stem cell hierarchy, but rather a reversible continuum. The stem cell (hematopoietic and non‐hematopoietic) phenotype, the total differentiation capacity (hematopoietic and non‐hematopoietic), gene expression as well as other stem cell functional characteristics (homing, receptor and adhesion molecule expression) vary throughout a cell‐cycle transit widely. This seems to be dependent on shifting chromatin and gene expression with cell‐cycle transit. The published data on DNA methylation, histone acetylation, and also RNAi, the major regulators of gene expression, conjoins very well and provides an explanation for the major issues of stem cell biology. Those features of stem cells mentioned above can be rather difficult to apprehend when a classical hierarchy biology view is applied, but they become clear and easier to understand once they are correlated with the underlining epigenetic changes. We are entering a new era of stem cell biology the era of “chromatinomics.” We are one step closer to the practical use of cellular therapy for degenerative diseases. J. Cell. Physiol. 201: 1–16, 2004. © 2004 Wiley‐Liss, Inc.
Chloride channels in the small intestinal cell line IEC‐18
Authors: Basavappa Srisaila , Vulapalli Sreesatya Raju , Zhang Hui , Yule David , Coon Steven , Sundaram Uma 
Published: May 2004

AbstractSmall intestinal crypt cells play a critical role in modulating Cl− secretion during digestion. The types of Cl− channels mediating Cl− secretion in the small intestine was investigated using the intestinal epithelial cell line, IEC‐18, which was derived from rat small intestine crypt cells. In initial radioisotope efflux studies, exposure to forskolin, ionomycin or a decrease in extracellular osmolarity significantly increased 36Cl efflux as compared to control cells. Whole cell patch clamp techniques were subsequently used to examine in more detail the swelling‐, Ca2+‐, and cAMP‐activated Cl− conductance. Decreasing the extracellular osmolarity from 290 to 200 mOsm activated a large outwardly rectifying Cl− current that was voltage‐independent and had an anion selectivity of I− > Cl−. Increasing cytosolic Ca2+ by ionomycin activated whole cell Cl− currents, which were also outwardly rectifying but were voltage‐dependent. The increase in intracellular Ca2+ levels with ionomycin was confirmed with fura‐2 loaded IEC‐18 cells. A third type of whole cell Cl− current was observed after increases in intracellular cAMP induced by forskolin. These cAMP‐activated Cl− currents have properties consistent with cystic fibrosis transmembrane regulator (CFTR) Cl− channels, as the currents were blocked by glibenclamide or NPPB but insensitive to DIDS. In addition, the current–voltage relationship was linear and had an anion selectivity of Cl− > I−. Confocal immunofluorescence studies and Western blots with two different anti‐CFTR antibodies confirmed the expression of CFTR. These results suggest that small intestinal crypt cells express multiple types of Cl− channels, which may all contribute to net Cl− secretion. © 2005 Wiley‐Liss, Inc.
Mouse HFE inhibits Tf‐uptake and iron accumulation but induces non‐transferrin bound iron (NTBI)‐uptake in transformed mouse fibroblasts
Authors: Kielmanowicz Merav Gleit , Laham Nihay , Coligan John E. , Lemonnier François , Ehrlich Rachel 
Published: May 2004

AbstractIron‐uptake and storage are tightly regulated to guarantee sufficient iron for essential cellular processes and to prevent the production of damaging free radicals. A non‐classical class I MHC molecule, the hemochromatosis factor (HFE), has been shown to regulate iron metabolism, potentially via its interaction with the transferrin receptor. Whereas, the effect of human HFE (hHFE) on transferrin/transferrin receptor association, as well as on transferrin receptor recycling and the level of cellular iron pools in various cell lines was analyzed, very little is known about the mouse HFE (mHFE) protein. In the following study, our aim was to analyze in more detail the function of mHFE. Surprisingly, we observed that over‐expression of mHFE, but not of hHFE, in a mouse transformed cell line, results in a most significant inhibition of transferrin‐uptake which correlated with apoptotic cell death. mHFE inhibited transferrin‐uptake immediately following transfection and this inhibition persisted in the surviving stable transfectants. Concomitantly, cellular iron derived from transferrin‐iron uptake was dramatically limited. The activation of a non‐transferrin bound iron‐uptake pathway that functions in the stable mHFE‐transfected clones could explain their normal growth curves and survival. The hypothesis that iron starvation can induce iron‐uptake by a novel transferrin‐independent pathway is discussed. © 2005 Wiley‐Liss, Inc.
Analysis of myocardial perfusion MRI
Authors: Jerosch‐Herold Michael , Seethamraju Ravi Teja , Swingen Cory M. , Wilke Norbert M. , Stillman Arthur E. 
Published: May 2004

AbstractRapid MR imaging (MRI) during the first pass of an injected tracer is used to assess myocardial perfusion with a spatial resolution of 2–3 mm, and to detect any regional impairments of myocardial blood flow (MBF) that may lead to ischemia. The spatial resolution is sufficient to detect flow reductions that are limited to the subendocardial layer. The capacity of the coronary system to increase MBF severalfold in response to vasodilation can be quantified by analysis of the myocardial contrast enhancement. The myocardial perfusion reserve (MPR) is a useful concept for quantifying the vasodilator response. The perfusion reserve can be estimated from the ratio of MBFs during vasodilation and at baseline, in units identical to those used for invasive measurements with labeled microspheres, or from dimensionless flow indices normalized by their value for autoregulated flow at rest. The perfusion reserve can be reduced as a result of a blunted hyperemic response and/or an abnormal resting blood flow. The absolute quantification of MBF removes uncertainties in the evaluation of the vasodilator response, and can be achieved without the use of complex tracer kinetic models; therefore, its application to clinical studies is feasible. J. Magn. Reson. Imaging 2004;19:758–770. © 2004 Wiley‐Liss, Inc.
Imaging of coronary calcification by computed tomography
Authors: Thompson Brad H. , Stanford William 
Published: May 2004

AbstractAs an unequivocal biomarker for arteriosclerosis, the presence of coronary calcium serves as a qualitative reflection of the severity of coronary artery disease (CAD). Greater calcium burdens correlate with more advanced disease, a higher likelihood of coronary stenoses, and a higher risk for coronary heart disease (CHD). Empirically, the quantification of coronary calcium not only provides an accurate reflection of disease severity, but also has great potential as a screening tool for CHD. Computed tomography (CT) has been shown to be capable of providing accurate, noninvasive measurements of coronary calcification. Evidence shows that calcium measurements by CT correlate well with histological plaque analyses, and that calcium burdens accurately reflect disease severity and can be used to assess individual risk for CHD. The purpose of this review article is to examine the accumulated evidence that has attempted to validate CT as a diagnostic tool for CAD and as a screening exam for CHD. J. Magn. Reson. Imaging 2004;19:720–733. © 2004 Wiley‐Liss, Inc.
MR and CT assessment for ischemic cardiac disease
Authors: White Richard D. 
Published: May 2004

AbstractMagnetic resonance imaging and/or contrast‐enhanced multidetector computed tomography may be used separately or, often more effectively, in an integrated fashion, to address important issues in patients with coronary artery disease causing ischemic cardiac disease (ICD). These issues include complications of myocardial infarction, such as ventricular dysfunction, myocardial wall rupture, aneurysm formation, intracavitary thrombus, mitral insufficiency, and pericarditis, as well as aspects of planning and monitoring therapy for ICD, such as revascularization and ventricular aneurysm repair. J. Magn. Reson. Imaging 2004;19:659–675. © 2004 Wiley‐Liss, Inc.
MRI of atherosclerosis
Authors: Yuan Chun , Kerwin William S. 
Published: May 2004

AbstractThe emergence of high‐resolution, rapid imaging methods has enabled MRI to noninvasively image the fine internal structure of atherosclerotic artery walls. This capability has, in turn, captured the interest of clinicians, who see it as an opportunity to assess disease severity based on the characteristics of atherosclerotic lesions themselves, rather than only their effects on the vessel lumen. MRI of atherosclerosis thus has the potential to be used in medical treatment decisions or to assess the effects of experimental treatment options. Given this potential, a number of research groups have been investigating MRI of atherosclerosis in an effort to establish the ability of MRI to determine atherosclerotic plaque burden, detect plaque composition, and ultimately identify vulnerable plaque before it leads to a clinical event. In this review, the current state of the art is summarized for the three primary vessel targets: the carotid artery, the aorta, and the coronary arteries. J. Magn. Reson. Imaging 2004;19:710–719. © 2004 Wiley‐Liss, Inc.
Magnetic resonance imaging–guided coronary interventions
Authors: Tsekos Nikolaos V. , Atalar Ergin , Li Debiao , Omary Reed A. , Serfaty Jean‐Michel , Woodard Pamela K. 
Published: May 2004

AbstractMagnetic resonance imaging (MRI) guidance for coronary interventions offers potential advantages over conventional x‐ray angiography. Advantages include the use of nonionizing radiation, combined assessment of anatomy and function, and three‐dimensional assessment of the coronary arteries leading to the myocardium. These advantages have prompted a series of recent studies in this field. Real‐time coronary MR angiography, with low‐dose catheter‐directed intraarterial (IA) infusion of contrast media, has achieved in‐plane spatial resolution as low as 0.8 × 0.8 mm2 and temporal resolution as short as 130 msec per image. Catheter‐based IA injection of contrast agent has proven useful in the collection of multislice and three‐dimensional images, not only for coronary intervention guidance, but also in the assessment of regional myocardial perfusion fed by the affected vessel. Actively visible guidewires and guiding catheters, based on the loopless antenna concept, have been effectively used to negotiate tortuous coronary vessels during catheterization, permitting placement of coronary angioplasty balloon catheters. Passive tracking approaches have been used to image contrast agent–filled coronary catheters and to place susceptibility‐based endovascular stents. Although the field is in its infancy, these early results demonstrate the feasibility for performing MRI‐guided coronary interventions. Although further methodological and technical developments are required before these methods become clinically applicable, we anticipate that MRI someday will be included in the armamentarium of techniques used to diagnose and treat coronary artery disease. J. Magn. Reson. Imaging 2004;19:734–749. © 2004 Wiley‐Liss, Inc.
Imaging of myocardial perfusion with magnetic resonance
Authors: Barkhausen Jörg , Hunold Peter , Jochims Markus , Debatin Jörg F. 
Published: May 2004

AbstractCoronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ‐specific parameters such as myocardial function at stress and first‐pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first‐pass MR imaging (MRI) of myocardial perfusion. J. Magn. Reson. Imaging 2004;19:750–757. © 2004 Wiley‐Liss, Inc.
Coronary artery magnetic resonance angiography
Authors: Flamm Scott D. , Muthupillai Raja 
Published: May 2004

AbstractCoronary magnetic resonance angiography (coronary MRA) continues to advance rapidly from both a technical and clinical perspective. Coronary MRA has benefited directly from improvements in spatial resolution, contrast definition, and advances in motion correction, which have furthered its routine use in evaluating coronary artery bypass grafts and anomalous coronary arteries. Work in refining the techniques for more accurate identification of coronary artery disease (CAD) continues, with advances in navigator‐gated and breath‐hold motion correction techniques, novel k‐space strategies (e.g., spiral and radial k‐space filling), development and application of intravascular contrast agents, and imaging at higher field strengths. Ultimately, these developments may lead to the routine application of coronary MRA as a screening tool for CAD. This article reviews the development of coronary MRA, discusses the requirements and tools necessary for optimal visualization of the coronary arteries, and describes the application of coronary MRA to acquired and congenital CAD. J. Magn. Reson. Imaging 2004;19:686–709. © 2004 Wiley‐Liss, Inc.
Magnetic resonance imaging for the assessment of myocardial viability
Authors: Thomson Louise E.J. , Kim Raymond J. , Judd Robert M. 
Published: May 2004

AbstractThe identification of myocardial viability in the setting of left ventricular (LV) dysfunction is crucial for the prediction of functional recovery following revascularization. Although echocardiography, positron emission tomography (PET), and nuclear imaging have validated roles, recent advances in cardiac magnetic resonance (CMR) technology and availability have led to increased experience in CMR for identification of myocardial viability. CMR has unique advantages in the ability of magnetic resonance spectroscopy (MRS) to measure subcellular components of myocardium, and in the image resolution of magnetic resonance proton imaging. As a result of excellent image resolution and advances in pulse sequences and coil technology, magnetic resonance imaging (MRI) can be used to identify the transmural extent of myocardial infarction (MI) in vivo for the first time. This review of the role of CMR in myocardial viability imaging describes the acute and chronic settings of ventricular dysfunction and concepts regarding the underlying pathophysiology. Recent advances in MRS and MRI are discussed, including the potential for dobutamine MRI to identify viable myocardium and a detailed review of the technique of delayed gadolinium (Gd) contrast hyperenhancement for visualization of viable and nonviable myocardium. J. Magn. Reson. Imaging 2004;18:771–788. © 2004 Wiley‐Liss, Inc.