bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Microeconomic Dynamics and Challenges in Vegetable-Based Farming System
Authors: Barman Sinki , Das Pallabi , Deka Pallavi , Borah Ajanta , Deka Animesh , Nath Dipen Ch , Borkakati Rudra Narayan , Neog Manoranjan
Published: February 2024

Horticulture based farming could be one of the potential sources to increase the income of farmers and employment generation in agrarian agriculture, as well as meeting the demand for healthy foods with changing consumption habit of the growing population. Therefore, during 2020-21, present study was conducted in Nagaon district of Assam with a sample size of 100 farmers using multistage random sampling where pretested schedule was used by PRA and interview method to examine the status, income, employment, and problems associated with horticulture-based farming system. Arecanut and coconut are found to be the common crops grown by all the selected farmers and the highest net return of Rs.298480 per ha from Vegetables+ Livestock component+ Spices +Coconut/Arecanut farming system out of the 6 selected farming systems. The labour employment was highest in Rice +Vegetables +Toria +Fishery+ Coconut/Arecanut farming system. In order to prioritize the problem, Pareto analysis is done and it has been found that animal menace and pest and disease are the major production problems causing (› 80 %) out of total 10 production problems. Marketing problems like processing, assembling and storage facility are major problems causing (› 80 % problems) among the sample farmers. To deal with the problems these farmers should be given proper training on management of animal and pest menace, proper storage facilities and post-harvest management. This may be the best strategy to address the yield loss occurs due to spoilage.
PATRIMÔNIO GEOLÓGICO DO TIPO ESTRUTURAL
Authors: Pereira Luciano
Published: February 2024

O Patrimônio Geológico, que pode ser paleontológico, estratigráfico, petrográfico, mineiro, mineralógico ou tectônico/estrutural, de uma área corresponde ao somatório de geossítios que possuem valores excepcionais e que, desta maneira, podem ser utilizados para a prática do geoturismo ou para fins geoconservacionistas. Assim, foi realizado um inventário de reconhecimento, através do preenchimento de uma ficha contendo uma série de informações, com o intuito de se identificar potenciais geossítios presentes nas redondezas do município de São Gabriel (RS), uma região com complexa associação de tipos litológicos, que pertençam ao Patrimônio Geológico da área no viés tectono/estrutural. Foi selecionado, ao final, um geossítio, apresentado neste artigo, classificado como um gnáisse quartzo-feldspático com biotita, de idade Proterozóica. Este corpo possui elevado valor científico por apresentar preservados dois eventos deformacionais, quatro fases de deformação e dois eventos metamórficos distintos, propiciando, assim entender a dinâmica estrutural/tectônica do Bloco São Gabriel.
Pediatric Endoscopic Nasal and Sinus Surgery
Authors: Stankiewicz James A.
Published: November 2005

A total of 83 children and teenagers underwent endoscopic nasal and sinus surgery. Six patients had surgery for choanal atresia (4) and adenoid hypertrophy (2) and will only be briefly mentioned. Seventy‐seven children and teenagers underwent endoscopic sinus surgery for acute and chronic sinusitis, choanal polyposis, and nasal polyposis with a minimum 2‐year follow‐up. One hundred thirty‐three ethmoidectomies, 37 sphenoidotomies, and 119 maxillary antrostomies were performed. Subjective evaluation of the sinus surgery patients indicated that 38% of patients were cured and 55% improved during an average of 3.5 years of follow‐up. The number cured and number improved are lower and higher, respectively, than in other reports of results because of the longer follow‐up and patient selection. In addition, objective data were obtained on 34 patients with a second‐ or third‐look procedure 2 weeks to 2 months after surgery. These examinations found significant granulation tissue, and almost 50% of patients had at least one maxillary ostia closed. Long‐term objective results, however, are not available to determine whether the ostia remained closed. Problems with healing in children's endoscopic sinus surgery are unpredictable compared those in adult surgery because postoperative debridement and examination are often difficult to perform, thus allowing tissue to heal without control. In this series, other factors such as the increased risks of cystic fibrosis, allergy, and immunodeficiency were also more prevalent and compromised healing. The best way to achieve good results in pediatric endoscopic sinus surgery requires appropriate patient selection, careful techniques, spacers or stents that don't cover the antrostomy, appropriate second‐ or third‐look procedures for debridement and examination, and judicious postoperative medical therapy.
Tracheostomal Stenosis after Laryngectomy: Incidence and Predisposing Factors
Authors: Wax Mark K. , Touma B. Joseph , Ramadan Hassan H.
Published: November 2005

Laryngectomy for carcinoma of the larynx has been performed since it was first described in 1880. Since that time the complication of tracheostomal stenosis has plagued both surgeons and patients. The reported incidence of tracheostomal stenosis ranges from 4% to 42%. At West Virginia University Hospitals from 1976 to 1994, 106 patients undergoing laryngectomies on the head and neck oncology service were analyzed. The charts of patients treated before 1991 were reviewed retrospectively; a prospective analysis was initiated in 1991. Only patients with a minimum of 6 months of follow‐up were included in this study. The male‐to‐female ratio was 3:1, with an age range of 28 to 86 years (mean, 58 years). The overall rate of stenosis was 28.4%. The incidence of tracheostomal stenosis was higher in women (46.4%) than in men (21.6%) (p< 0.05). Since 1991 a plastic type of closure was used in 25 patients. The stenosis rate was 0% in these patients. Before 1991 a bevel or circle technique was used, with stenosis rates of 33% and 75%, respectively (p< 0.05). Infection at the site of the stoma, fistula, steroid use, neck dissection, pectoralis major myocutaneous flap usage, primary tracheoesophageal puncture, and radiotherapy did not correlate with an increased incidence of stenosis. The most important factor in prevention of stomal stenosis after laryngectomy is attention to detail while forming the stoma. With good technique and a plastic‐type closure to break up the suture line, a minimal rate of stenosis should be encountered.
Effects of Driving Pressure and Recurrent Laryngeal Nerve Stimulation on Glottic Vibration in a Constant Pressure Model
Authors: Verneuil Andrew , Kreiman Jody , Kevorkian Kevin , Ye Ming , Gerratt Bruce R. , Berke Gerald S.
Published: November 2005

Glottic phonatory parameters have been studied in constant flow models; however, the lung‐thorax system is better viewed as a constant pressure source. Adjusting the driving pressure and recurrent laryngeal nerve stimulation as independent variables, rather than as dependent variables, may provide a more physiologic understanding of laryngeal function and glottic parameters, including subglottic pressure, airflow, fundamental frequency, and glottic area. In three dogs subglottic pressure and airflow were measured in two separate conditions: with constant recurrent laryngeal nerve stimulation and varying driving pressure, and with constant driving pressure and varying recurrent laryngeal nerve stimulation. Videostroboscopic measures on four dogs assessed glottic areas with constant recurrent laryngeal nerve stimulation at different driving pressures. With constant recurrent laryngeal nerve stimulation, increasing driving pressure had no effect on glottic areas, whereas subglottic pressure, fundamental frequency, and airflow increased significantly. However, changes in subglottic pressure were minimal in comparison with changes in driving pressure. At constant driving pressure, increasing recurrent laryngeal nerve stimulation increased subglottic pressure and fundamental frequency and decreased airflow. These findings suggest that during phonation subglottic pressure is primarily dependent on recurrent laryngeal nerve stimulation and laryngeal muscular contraction, but not on lung driving pressure.
Chondrosarcoma of the Nasal Septum: Skull Base Imaging and Clinicopathologic Correlation
Authors: Rassekh Christopher H. , Nuss Daniel W. , Kapadia Silloo B. , Curtin Hugh D. , Weissman Jane L. , Janecka Ivo P.
Published: November 2005

Chondrosarcoma arising in the head and neck and craniofacial region is an uncommon lesion. The nasal septum is a particularly rare site of origin, with approximately 30 cases previously reported in the English literature. We present six new cases of chondrosarcoma arising in the nasal septum. Each of these tumors required cranial base surgical approaches for removal. Current imaging techniques allow a very accurate diagnosis to be made before biopsy. The characteristic ring‐forming calcifications seen on computed tomography scans can be correlated with the histologic pattern of calcification. Magnetic resonance imaging techniques allow precise definition of tumor extent, which is particularly important because the disease is best treated with primary surgery. Advances in imaging and surgical techniques allow a much more complete tumor removal. It is hoped that this will increase the likelihood of cure in these patients. Surgical management and indications for adjuvant therapy are discussed.
Massive, Destructive, Dentigerous Cyst: A Case Report
Authors: Meara John G. , Brown Mark T. , Caradonna David , Varvares Mark A.
Published: November 2005

Dentigerous cysts are relatively common odontogenic abnormalities that develop around unerupted maxillary or mandibular teeth. These are often asymptomatic and found incidentally on dental radiographs. Occasionally, they can be large and cause symptoms related to expansion and impingement on contiguous structures. Herein we present the first reported case to our knowledge of a maxillary dentigerous cyst presenting as a bleeding intraoral mass with associated extensive maxillary destruction.
Adult Acute Epiglottitis Caused by Serratia morcescens
Authors: Bower Charles M. , Suen James Y.
Published: November 2005

Acute epiglottitis has historically been a common disease in the pediatric population, with relatively few adult cases reported. Because of the introduction of the Haemophilus influenzae vaccine in the recent past, acute epiglottitis in children has become uncommon. In contrast, an increasing number of cases of epiglottitis in adults have been described.1 Although the incidence in children has declined from 3.5 cases per 100,000 population per year to 0.6 cases per 100,000 per year, the adult incidence has remained relatively stable at 1.8 cases per 100,000. As in children, adult epiglottitis is manifest by dysphagia, odynophagia, and occasionally stridor progressing to airway obstruction. Although in the pediatric patients H. influenzae is the most common causative agent, the majority of adults are not culture positive for a specific pathogen.1,2 Also, in adults, a variety of infectious agents have been identified, including pneumonococcal species and Candida, especially in immunocompromised patients.3,4 However, to date, no cases of Serratia marcescens epiglottitis have been described. This article reports two adult immunocompromised patients with well–documented S. marcescens epiglottitis. A review of the presentation and treatment of adult patients with epiglottitis is included.
Arytenoid Dislocation
Authors: Faries Peter L. , T. Martella Arthur
Published: November 2005

Arytenoid dislocation is a rare complication of endotracheal intubation and blunt trauma. Respiratory distress is the most significant complication of dislocation. Eleven cases of this unusual entity have been described previously.1–8 Of these only three have been associated with significant airway compromise. In each case the onset of respiratory distress occurred within 4 hours of extubation and necessitated tracheostomy.7,8 We describe a case of arytenoid dislocation that precipitated respiratory distress 40 hours after extubation and provide a complete review of the literature.
Nasal Septal Perforation and Carotid Cavernous Aneurysm: Unusual Manifestations of Systemic Lupus Erythematosus
Authors: Lerner Don N.
Published: November 2005

Systemic lupus erythematosus (SLE) is a multisystem collagen vascular disorder defined by its clinical features and the presence of antibodies in the blood directed against one or more cell nuclei components. Typically, SLE affects the head and neck in the form of cutaneous malar erythema and oropharyngeal mucosal ulcerations. The uncommon findings of nasal septal perforations and restrictive central nervous system (CNS) aneurysmal formation as initial manifestations of SLE are detailed in this case report.
The quality of life of older and younger people who receive renal replacement therapy
Authors: McKEE KEVIN J. , PARKER STUART G. , ELVISH JENNIFER , CLUBB VINCE J. , EL NAHAS MEGUID , KENDRAY DEBORAH , CREAMER NICOLA
Published: November 2005

The use of age as a criterion for the allocation of medical resources has been extensively debated internationally. This paper describes a study of the significance of age for the quality of life (QoL) of older and younger people with end-stage renal failure (ESRF) and in receipt of renal replacement therapy (RRT). The study has two components: a structured literature review to characterise the QoL and health-status measurement instruments that have been developed for use with all or specifically older RRT patients; and a longitudinal survey of the QoL domains nominated by older RRT patients by their age and duration of treatment. The literature review found that no validated QoL instrument had been developed specifically for use with older RRT patients. Moreover, there was little correspondence between the QoL domains used in the instruments described in the published literature and those mentioned by the survey participants. Older and younger patients nominated different domains, and their nominations changed with the duration of treatment. No significant differences in QoL scores were found between older and younger patients, but the scores improved significantly between 6–12 and 18–24 months of treatment. The findings suggest that using older age as a criterion for refusing full access to healthcare resources in ESRF is a simplistic and potentially erroneous strategy.
Are today's older people more active than their predecessors? Participation in leisure-time activities in Sweden in 1992 and 2002
Authors: AGAHI NEDA , PARKER MARTI G.
Published: November 2005

For the older individual, leisure activities are a resource that helps to maintain health and engagement with life. This article investigates change over 10 years in the level of participation of older people in leisure activities in Sweden, and the factors associated with these changes. The data are from nationally representative samples of the Swedish population aged 77 or more years in 1992 and 2002. The level of participation was higher at the later date, and among four major groups of activities, social and cultural activities increased the most, while physical and intellectual activities increased only among women. Ordered logistic regressions enable variations in the level of participation by age, gender, level of education, disability and fatigue to be described. Participation in most kinds of activities, including the overall level, was more common at the younger ages (the late seventies and early eighties) and among those with full mobility and more education. Since average health was worse in 2002 than in 1992, it cannot explain the higher level of participation. Other possible explanations, such as cohort differences, improved accessibility, and changing gender roles, and the implications for health promotion programmes are discussed.
25th volume celebration paper
Towards an international political economy of ageing
Authors: WALKER ALAN
Published: November 2005

This article is an initial scoping exercise for a research agenda on the international political economy of ageing. It begins with a brief review of the various critiques of the political economy perspective that have been made over the 25 years since the first article on the subject. Remarkable for its absence has been criticism of the neglect of an explicit international perspective. Then the article emphasises that it is not globalisation per se that is problematic but its dominant neo-liberal economic form. It is mainly because of this globalisation and the related growth in the power of international governmental organisations, such as The World Bank, that an international political economy of ageing is required. The bulk of the article is devoted to an outline of the eight key elements that might comprise a theoretical and empirical research agenda for social gerontology. These key elements are: global inequality in old age, development and ageing, globalism and the power of international governmental organisations, trans-national corporations, the nation state, supra-national regional structures, the United Nations, and international non-governmental organisations. In the spirit of the other articles that have celebrated the journal's 25th anniversary, this paper is intended to stimulate scientific debate.
Resolving trade disputes arising from trends in food safety regulation: the role of the multilateral governance framework
Authors: ROBERTS DONNA , UNNEVEHR LAURIAN
Published: November 2005

New food regulations may impede international trade, but multilateral mechanisms can resolve trade conflicts when they do arise. Food safety regulation in industrialized countries during the 1990s increasingly uses risk analysis in a farm-to-table approach, promotes the Hazard Analysis and Critical Control Point (HACCP) system, and increases the stringency of standards or creates new regulations for hazards. The 1995 Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement), negotiated by World Trade Organization (WTO) members, establishes a framework to reduce their trade distorting aspects. Three of the principles under the SPS Agreement – science-based risk assessment, equivalence, and harmonization – directly address aspects of food safety regulation that create the potential for trade disputes. In many cases, the science requirements of the Agreement have led to the elimination of unnecessary regulatory barriers to trade. However, some high profile cases remain unresolved because of gaps in convergence around risk management principles that were not spelled out in the Agreement in deference to national sovereignty. The evidence also indicates that there has been limited progress in reducing regulatory transactions costs to trade in food through equivalence or harmonization.
The future of the WTO: some comments on the Sutherland Report
Authors: BLACKHURST RICHARD
Published: November 2005

Three times since its founding in 1948, the GATT/WTO has turned to outside experts for help in finding solutions to pressing issues confronting the multilateral trading system. In 1957 the Contracting Parties decided to create a panel of three (later four) internationally recognized experts in international trade and finance to consider trends in world trade, andin particular the failure of the trade of the less developed countries to develop as rapidly as that of industrialized countries, excessive short-term fluctuations in prices of primary products, and widespread resort to agricultural protection.
So far, so good: but what next? The Sutherland Report and WTO dispute settlement
Authors: MEAGHER NIALL
Published: November 2005

This comment will focus primarily on the Sutherland Report's analysis of and recommendations for the WTO dispute settlement system. Before turning to the specific issue of dispute settlement, however, it is necessary to make a few introductory remarks regarding the objectives of the Sutherland Report, as well as its view of the future role of the WTO, including the dispute settlement system, in the international political system.
The role of the Director-General and Secretariat: Chapter IX of the Sutherland Report
Authors: SHAFFER GREGORY
Published: November 2005

Chapter IX of the ‘Report of the Consultative Board on The Future of the WTO’ concerns ‘The role of the WTO Director-General and Secretariat’. The report generally expresses concern that the WTO secretariat, although ‘highly skilled’ and ‘well-regarded’ has become ‘more timid’ and passive than in the past, and that the ‘mutual confidence’ between delegations and WTO staff has declined. The report finds that the Director-General has become more of a ‘spokesperson and marketing executive’ for the organization than a leader who represents a driving, proactive force in the shaping and brokering of trade negotiations, as compared with the past where Directors-Generals ‘were sometimes regarded virtually as spiritual leaders of the system’. It warns that the costs of such a trend will be ‘lost efficiency’ and a loss of intellectual leadership.
Expanding WTO membership and heterogeneous interests
Authors: HOEKMAN BERNARD
Published: November 2005

In late 2004, the Consultative Board to the WTO Director General issued its report, ‘The Future of the WTO: Addressing the Institutional Challenges in the New Millennium’. As noted by the Director General in the foreword, a rationale for the report was that ‘there had been too little serious thinking on whether the institutional design and practice that had served the GATT so well would do the same for the WTO’. One of the specific questions raised was ‘Could the WTO with an enlarged membership at various levels of development continue to deliver results?’ (p. 2). The following reflection on the Consultative Board's report is motivated by the latter question, where ‘results’ is defined as promoting not just global economic welfare, but the development prospects of poor members.
The role of molecular interactions and interfaces in diffusion: Transport diffusivity and evaluation of the Darken approximation
Authors: Snyder M. A. , Vlachos D. G.
Published: November 2005

Kinetic Monte Carlo (KMC) simulations are carried out to directly study diffusion of benzene through thin (37–100nm) NaX zeolite membranes under a gradient in chemical potential. Nonlinearities in adsorbate loading near the membrane boundaries are shown to arise from the difference in adsorbate density between the zeolite and adjacent fluid phase. Direct extraction of the transport diffusivity from gradient KMC simulations enables testing of the Darken approximation. This rigorous approach reveals limitations of the Darken approximation and, for the first time, the potentially complex nonunique functionality and multiplicity of the transport diffusivity for strongly interacting adsorbates. In the companion paper we explore these nonlinear interfacial effects in the context of permeation through both single-crystal and polycrystalline membranes.
The role of molecular interactions and interfaces in diffusion: Permeation through single-crystal and polycrystalline microporous membranes
Authors: Snyder M. A. , Vlachos D. G.
Published: November 2005

In this second paper of a two part series, we investigate the implications of the interfacial phenomenon, caused by adsorbate-adsorbate interactions coupled with the difference in adsorbate density between the zeolite and the gas phase, upon benzene permeation through single-crystal and polycrystalline microporous NaX membranes. The high flux predicted for thin single-crystal membranes reveals that substantially enhanced flux should be expected in submicron films. Simulations also indicate that the standard local equilibrium assumption made for larger scale membranes is inapplicable at the submicron scale associated with nanometer size grains of thin and/or polycrystalline membranes. Apparent activation energies predicted for benzene permeation through NaX membranes via kinetic Monte Carlo (KMC) simulations are in good agreement with laboratory experiments. The simulations also uncover temperature-dependent flux pathways leading to non-Arrhenius behavior observed experimentally. The failure of the Darken approximation, especially in the presence of the interfacial phenomenon, leads to a substantial overprediction of the flux. Simulations of polycrystalline membranes suggest that this same interfacial phenomenon leads to resistance that can reduce flux by an order of a magnitude with only moderate polycrystallinity.
Extensive ab initio study of the electronic states of SCl including spin-orbit coupling
Authors: Yang Xinzheng , Boggs James E.
Published: November 2005

The effect of different basis sets for calculation of the spectroscopic constants of the ground state of sulfur monochloride (SCl) was analyzed using scalar relativistic multireference configuration interaction with single and double excitations plus Davidson correction. Then the generally contracted all-electronic correlation-consistent polarized valence quintuple zeta basis sets were selected to compute the electronic states of SCl including 12 valence and 9 Rydberg Λ−S states. The spin-orbit coupling effect was calculated via the state interaction approach with the full Breit-Pauli Hamiltonian. This effect splits these Λ−S states into 42Ω states. Potential-energy curves of all these states are plotted with the help of the avoided crossing rule between the electronic states of the same symmetry. The structural properties of these states are analyzed. Spectroscopic constants of bound excited states that have never been observed in experiment are obtained. The transition dipole moments and the Franck-Condon factors of several transitions from low-lying bound excited states to the ground state were also calculated.
Effect of gain localization in circular-grating distributed feedback lasers
Authors: Turnbull G. A. , Carleton A. , Tahraouhi A. , Krauss T. F. , Samuel I. D. W. , Barlow G. F. , Shore K. A.
Published: November 2005

We explore the influence of gain localization on the lasing performance of circular-grating distributed feedback (CDFB) lasers. The effect is studied in an optically pumped CDFB laser resonator based on a waveguide of the conjugated polymer poly[2-methoxy-5-(2′ethylhexyloxy)-1,4-phenylene vinylene]. Variations in lasing threshold and slope efficiency are determined as a function of the radius of the optical excitation. The experimental lasing results are compared with predictions from a theoretical analysis based on an adaptation of the transfer matrix method. We find that a strong localization of the gain near the center of the CDFB laser can lead to both a substantial reduction in threshold and increase in output efficiency. As the excitation radius changes from a 90 to a 15μm radius, the threshold energy decreases from 5.3to0.29nJ, and the surface-emitted output efficiency increases by an order of magnitude. A simple model is developed that confirms that the significant reduction in threshold can be explained by an enhanced overlap of the population inversion with the resonant mode.
Pore interconnectivity of nanoclustering silica porous films as studied by positronium time-of-flight spectroscopy
Authors: Ito Kenji , Yu Run-Sheng , Sato Kiminori , Hirata Kouichi , Kobayashi Yoshinori , Kurihara Toshikazu , Egami Miki , Arao Hiroki , Nakashima Akira , Komatsu Michio
Published: November 2005

Positronium time-of-flight spectroscopy with improved stability and signal-to-noise ratio, achieved by a developed off-line digital data analysis, was applied to the characterization of three types of nanoclustering silica porous films with different relative dielectric constants and refractive indices. The emission of triplet ortho-positronium (o-Ps) from the film surface was examined as a function of incident positron energy (Ein). It was found that the o-Ps emission peak energies from two highly porous films with similar total porosities decrease similarly to each other with increasing Ein up to 1.50keV. On the other hand, o-Ps emission intensities from the two films differed considerably in the range between 0.5keV<Ein<4keV, which reflects a difference in pore interconnectivity between the two films with different mean secondary particle sizes. Some interconnected pores are expected to be closed by the necking at the particle contacts as calcination proceeds, possibly leading to more necks in the pores for the film with the smaller secondary particle size.
Extraction of electric power from plasma sources using difference in plasma-electrode interactions
Authors: Yagi Yasuyuki
Published: November 2005

It is investigated how much electric power can be extracted through electrodes inserted into plasmas. The difference in the size and secondary-electron emission coefficient of the material of electrodes, as well as the difference in the ambient plasma parameters, produces an imbalance in electron and ion currents at each electrode, and a net current, and hence a net electric power, can be driven in the external load connected between the electrodes. This forms a battery using the plasma medium. The extracted electric power is investigated as a function of the operating parameters. The results can be applied to various plasma sources: fusion plasmas, laboratory plasma sources in general, and space plasmas.
Hand-held thermal-regulating fluorometer
Authors: Farmer Andrew S. , Fries David P. , Flannery William , Massini John
Published: November 2005

This article relates to the construction of a portable, low cost, thermal-regulating light-emitting diode (LED)-based, handheld fluorometer. This regulated fluorometer is based on both a low thermal mass infrared heater, and an orthogonal geometry LED-based filter fluorometer. Power is supplied through an external power supply and data is collected in real time through standard serial interfaces of personal computers or personal digital assistants. Thermal regulation is automatically maintained using temperature sensor feedback control. Optical excitation relies on LED light source(s) and optical detection is made through an adjustable integrating photodetector. With such a handheld system, applications requiring temperature sensitive photometric measurements for real-time analyte detection can be more easily performed in the field.
On the stability of the Maxey-Riley equation in nonuniform linear flows
Authors: Kobayashi Marcelo H. , Coimbra Carlos F. M.
Published: November 2005

In this work, we address the stability of equilibrium points for particle motion in an important class of flows for which a consistent Lagrangian equation of motion for the particle can be derived and solved exactly. This class of flows includes all nonuniform, steady solenoidal flows that are characterized by constant vorticity and constant strain rate. We demonstrate that equilibrium points for particle motion exist for such flow fields and that, under some specific conditions, these equilibrium points are stable and therefore represent the observable steady-state solution of the Lagrangian equation of motion for the particle. We show that there exists an exact solution procedure for the Maxey-Riley equation of motion in all linear solenoidal flows. We also show that for two-dimensional linear solenoidal velocity fields characterized by closed streamlines, the stability of the equilibrium point for the particle motion is determined by the relative density of the particle with respect to the fluid: heavy particles produce unstable equilibrium points and light particles produce stable equilibrium points. For flows that are not characterized by closed streamlines, the equilibrium points for the particle motion for both heavy and light particles are unstable. Finally, we completely characterize three-dimensional linear solenoidal velocity fields that are solutions of the Navier-Stokes equations and establish the necessary and sufficient conditions for the stability of particle equilibrium points in such flows.
Use of single-walled carbon nanotubes to increase the quality factor of an AT-cut micromachined quartz resonator
Authors: Goyal Abhijat , Tadigadapa Srinivas , Gupta Awnish , Eklund Peter C.
Published: November 2005

In this letter, we report the suppression of loss mechanisms in an AT-cut quartz resonator operating in thickness shear mode using an over layer of single-walled carbon nanotubes (SWNTs), and the resulting increase in the Q (quality) factor of the resonator by as much as 100%. The Q factor was found to monotonically increase as more SWNTs were added to the resonator. The increase in the Q factor of the resonators is thought to arise due to suppression of surface loss modes due to interaction of the carbon nanotubes with the quartz resonator surface. The use of SWNTs provides a very effective and simple way to improve the performance of quartz resonators.
Electron paramagnetic resonance of manganese ions in CdTe detected by coherent Raman spectroscopy
Authors: Smith L. C. , Bingham S. J. , Davies J. J. , Wolverson D.
Published: November 2005

Electron paramagnetic resonance (EPR) signals of manganese ions in cadmium telluride have been detected optically by a coherent Raman heterodyne method. This technique circumvents the resolution limits of diffraction grating-based spectroscopy while providing the sensitivity and selectivity characteristic of resonant Raman scattering. The precision to which the spin Hamiltonian parameters of a given center can be determined is greatly enhanced and, here, the effects of the hyperfine interaction between the Mn2+3d electrons and the Mn nucleus on the line shape of the spectrum become apparent. The Raman scattering process is found to be strongly resonant with an excitonic intermediate state, due to the strong exchange coupling between band and Mn 3d states. This opens the way to optically site-selective EPR measurements of the symmetry, charge state and exchange interactions of transition metal ions in semiconductor quantum wells and dots.
Origin of the light intensity dependence of the short-circuit current of polymer/fullerene solar cells
Authors: Koster L. J. A. , Mihailetchi V. D. , Xie H. , Blom P. W. M.
Published: November 2005

A typical feature of polymer/fullerene based solar cells is that the current density under short-circuit conditions (Jsc) does not scale exactly linearly with light intensity (I). Instead, a power law relationship is found given by Jsc∝Iα, where α ranges from 0.85 to 1. In a number of reports this deviation from unity is speculated to arise from the occurrence of bimolecular recombination. We demonstrate that the dependence of the photocurrent in bulk heterojunction solar cells is governed by the build-up of space-charge in the device as a consequence of a difference in electron- and hole mobility. We have verified this for an experimental model system in which the mobility difference can be tuned from one to three orders of magnitude by changing the annealing treatment.
Energy band structure and electrical properties of (La2O3)1−x(SiO2)x(⩽x⩽1)∕n-GaAs(001) system
Authors: Yang Jun-Kyu , Park Hyung-Ho
Published: November 2005

This letter investigates the chemical bonding state and energy band structure of (La2O3)1−x(SiO2)x(0⩽x⩽1) films grown on sulfur-passivated n-GaAs (001). The dielectric bandgap and interfacial band alignment were modified by compounding the La2O3 films with SiO2. A shift in binding energy of the core level was observed by comparing the electronegativities of the second nearest-neighbor element. The controlled parameters of energy band structure were systematically monitored by valence band and absorption spectra. Band offset values were almost linearly related to the concentration of SiO2 when no Fermi level pinning in the midgap of n-GaAs was assumed. The correlation between band parameter and electrical properties, as probed by capacitance and leakage current measurements, is discussed.
Dynamic force spectroscopy of parallel individual Mucin1–antibody bonds
Authors: Sulchek Todd A. , Friddle Raymond W. , Langry Kevin , Lau Edmond Y. , Albrecht Huguette , Ratto Timothy V. , DeNardo Sally J. , Colvin Michael E. , Noy Aleksandr
Published: November 2005

We used atomic force microscopy to measure the binding forces between Mucin1 (MUC1) peptide and a single-chain variable fragment (scFv) antibody selected from a scFv library screened against MUC1. This binding interaction is central to the design of molecules used for targeted delivery of radioimmunotherapeutic agents for prostate and breast cancer treatment. Our experiments separated the specific binding interaction from nonspecific interactions by tethering the antibody and MUC1 molecules to the atomic force microscope tip and sample surface with flexible polymer spacers. Rupture force magnitude and elastic characteristics of the spacers allowed identification of the rupture events corresponding to different numbers of interacting proteins. We used dynamic force spectroscopy to estimate the intermolecular potential widths and equivalent thermodynamic off rates for monovalent, bivalent, and trivalent interactions. Measured interaction potential parameters agree with the results of molecular docking simulation. Our results demonstrate that an increase of the interaction valency leads to a precipitous decline in the dissociation rate. Binding forces measured for monovalent and multivalent interactions match the predictions of a Markovian model for the strength of multiple uncorrelated bonds in a parallel configuration. Our approach is promising for comparison of the specific effects of molecular modifications as well as for determination of the best configuration of antibody-based multivalent targeting agents.
Effect of modulating unfolded state structure on the folding kinetics of the villin headpiece subdomain
Authors: Brewer Scott H. , Vu Dung M. , Tang Yuefeng , Li Ying , Franzen Stefan , Raleigh Daniel P. , Dyer R. Brian
Published: November 2005

Equilibrium Fourier transform infrared (FTIR) and temperature-jump (T-jump) IR spectroscopic techniques were used to study the thermodynamics and kinetics of the unfolding and folding of the villin headpiece helical subdomain (HP36), a small three-helix protein. A double phenylalanine mutant (HP36 F47L, F51L) that destabilizes the hydrophobic core of this protein also was studied. The double mutant is less stable than wild type (WT) and has been shown to contain less residual secondary structure and tertiary contacts in its unfolded state. The relaxation kinetics after a T-jump perturbation were studied for both HP36 and HP36 F47L, F51L. Both proteins exhibited biphasic relaxation kinetics in response to a T-jump. The folding times for the WT (3.23 μs at 60.2°C) and double phenylalanine mutant (3.01 μs at 49.9°C) at the approximate midpoints of their thermal unfolding transitions were found to be similar. The folding time for the WT was determined to be 3.34 μs at 49.9°C, similar to the folding time of the double phenylalanine mutant at that temperature. The double phenylalanine mutant, however, unfolds faster with an unfolding time of 3.01 μs compared with 6.97 μs for the WT at 49.9°C.
The structural basis of myotonic dystrophy from the crystal structure of CUG repeats
Authors: Mooers Blaine H. M. , Logue Jeremy S. , Berglund J. Andrew
Published: November 2005

Myotonic dystrophy (DM) type 1 is associated with an expansion of (>50) CTG repeats within the 3′ untranslated region (UTR) of the dystrophin myotonin protein kinase gene (
dmpk
). In the corresponding mRNA transcript, the CUG repeats form an extended stem-loop structure. The double-stranded RNA of the stem sequesters RNA binding proteins away from their normal cellular targets resulting in aberrant transcription, alternative splicing patterns, or both, thereby leading to DM. To better understand the structural basis of DM type 1, we determined to 1.58-Å resolution the x-ray crystal structure of an 18-bp RNA containing six CUG repeats. The CUG repeats form antiparallel double-stranded helices that stack end-on-end in the crystal to form infinite, pseudocontinuous helices similar to the long CUG stem loops formed by the expanded CUG repeats in DM type 1. The CUG helix is very similar in structure to A-form RNA with the exception of the unique U-U mismatches. This structure provides a high-resolution view of a toxic, trinucleotide repeat RNA.
An essential RNase III insertion editing endonuclease in
Trypanosoma brucei
Authors: Carnes Jason , Trotter James Raffaello , Ernst Nancy Lewis , Steinberg Alodie , Stuart Kenneth
Published: November 2005

RNA editing adds and deletes uridine nucleotides in many preedited mRNAs to create translatable mRNAs in the mitochondria of the parasite
Trypanosoma brucei
. Kinetoplastid RNA editing protein B3 (KREPB3, formerly TbMP61) is part of the multiprotein complex that catalyzes editing in
T. brucei
and contains an RNase III motif that suggests nuclease function. Repression of KREPB3 expression, either by RNA interference in procyclic forms (PFs) or by conditional inactivation of an ectopic
KREPB3
allele in bloodstream forms (BFs) that lack both endogenous alleles, strongly inhibited growth and
in vivo
editing in PFs and completely blocked them in BFs. KREPB3 repression inhibited cleavage of insertion editing substrates but not deletion editing substrates
in vitro
, whereas the terminal uridylyl transferase, U-specific exoribonuclease, and ligase activities of editing were unaffected, and ≈20S editosomes were retained. Expression of
KREPB3
alleles with single amino acid mutations in the RNase III motif had similar consequences. These data indicate that KREPB3 is an RNA editing endonuclease that is specific for insertion sites and is accordingly renamed KREN2 (kinetoplastid RNA editing endonuclease 2).
Parkinson's disease-associated mutations in leucine-rich repeat kinase 2 augment kinase activity
Authors: West Andrew B. , Moore Darren J. , Biskup Saskia , Bugayenko Artem , Smith Wanli W. , Ross Christopher A. , Dawson Valina L. , Dawson Ted M.
Published: November 2005

Mutations in the leucine-rich repeat kinase 2 gene (
LRRK2
) cause late-onset Parkinson's disease (PD) with a clinical appearance indistinguishable from idiopathic PD. Initial studies suggest that
LRRK2
mutations are the most common yet identified determinant of PD susceptibility, transmitted in an autosomal-dominant mode of inheritance. Herein, we characterize the
LRRK2
gene and transcript in human brain and subclone the predominant ORF. Exogenously expressed LRRK2 protein migrates at ≈280 kDa and is present largely in the cytoplasm but also associates with the mitochondrial outer membrane. Familial-linked mutations G2019S or R1441C do not have an obvious effect on protein steady-state levels, turnover, or localization. However,
in vitro
kinase assays using full-length recombinant LRRK2 reveal an increase in activity caused by familial-linked mutations in both autophosphorylation and the phosphorylation of a generic substrate. These results suggest a gain-of-function mechanism for
LRRK2
-linked disease with a central role for kinase activity in the development of PD.
Relationship of insulin sensitivity to aerobic capacity in Standardbred mares and geldings
Authors: Pratt SE , Geor RJ , McCutcheon LJ
Published: November 2005

The objective of this study was to determine the relationship between insulin sensitivity and aerobic capacity and serum adipocytokine (leptin, adiponectin) concentrations in 14 mature, unconditioned Standardbred horses (eight mares, six geldings). Each horse underwent a euglycaemic–hyperinsulinaemic clamp (EHC) and a frequently sampled intravenous glucose tolerance test (FSIGT) for assessment of insulin sensitivity. Aerobic capacity was determined by measurement of the peak rate of oxygen uptake (V˙O2peak) during an incremental exercise test (IET). Serum leptin and adiponectin concentrations were measured in baseline samples obtained before tests of insulin sensitivity. Mean body weight, condition score, V˙O2peak and run time during the IET did not differ between the sex groups. However, minimal model analysis of the FSIGT showed that insulin sensitivity (SI, ×10−4 l mU−1 min−1) was higher (P = 0.002) in geldings (4.21±0.78) than in mares (2.43±0.95), while the acute insulin response to glucose (AIRg) and glucose utilization independent of insulin (SG) were significantly higher in mares. Similarly, glucose uptake (M) per unit of serum insulin (I) during the EHC (M/I ratio) tended (P = 0.08) to be higher in geldings than in mares (×10−2 mg kg−1 min−1 per μU ml−1: 2.41±0.64 vs. 1.80±0.51). There was no significant relationship between V˙O2peak and measures of insulin sensitivity. Stepwise multiple linear regression modelling determined that sex (65%) and leptin concentrations (13.7%) accounted for 78.7% of the variance in SI, while 46% of the variance in M/I could be attributed to sex. It was concluded that aerobic capacity is not an important determinant of insulin-mediated glucose disposal in mature, untrained Standardbred horses. Further studies are needed to examine the influence of gender on insulin sensitivity in horses.
Effects of ‘warm-up’ exercise on energy provision and exercise performance in horses and humans: a comparative review
Authors: Burnley Mark , Jones Andrew M.
Published: November 2005

Equine and human athletic endeavour often requires near-maximal rates of aerobic metabolism. It, therefore, follows that any practical method of increasing the aerobic contribution to exercise should be of benefit to athletic performance. Prior ‘warm-up’ exercise is widely advocated before exercise performance in order to ‘prime’ the physiological mechanisms of power generation and energy supply. In the present review, we examine evidence that prior exercise, in both the horse and the human, results in marked increases in O2supply and utilization during subsequent intense exercise. Much of this evidence stems from the study of pulmonary oxygen uptake dynamics and the related concepts of oxygen deficit and critical power. We, therefore, also review the effect of prior exercise in light of the exercise intensity domains in which the prior and subsequent exercise performances take place. Recent evidence suggests that both moderate and heavy exercise should improve subsequent severe exercise performance in both species by ∼2–3%, although much work remains to be done to establish the ‘optimal’ warm-up regime(s).
COMPAM :visualization of combining pairwise alignments for multiple genomes
Authors: Lee DoHoon , Choi Jeong-Hyeon , Dalkilic Mehmet M. , Kim Sun
Published: November 2005

Summary: COMPAM is a tool for visualizing relationships among multiple whole genomes by combining all pairwise genome alignments. It displays shared conserved regions (blocks) and where these blocks occur (edges) as block relation graphs which can be explored interactively. An unannotated genome, e.g. can then be explored using information from well-annotated genomes, COG-based genome annotation and genes. COMPAM can run either as a stand-alone application or through an applet that is provided as service to PLATCOM, a toolset for whole genome comparative analysis, where a wide variety of genomes can be easily selected. Features provided by COMPAM include the ability to export genome relationship information into file formats that can be used by other existing tools.

Availability:  

Contact:  dohhlee@indiana.edu; sunkim2@indiana.edu