Modern Methods (modern + methods)

Distribution by Scientific Domains


Selected Abstracts


Yield, Boll Distribution and Fibre Quality of Hybrid Cotton (Gossypium hirsutum L.) as influenced by Organic and Modern Methods of Cultivation

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2006
D. Blaise
Abstract India is the largest cotton-growing country (8.9 million hectares) in the world and most of the area is rain-dependent. Large amount of pesticides are used for the control of sucking pests and lepidopterans. Increasing demand for clean organic fibre has led to an interest in organic cotton. However, information on the effects of organic cultivation on fibre quality is limited. Seed cotton yield and fibre quality (length, strength, micronaire and uniformity) were determined for an organic and modern method of cultivation during 3 years (2002,2003 to 2004,2005) of a 11-year (1994,1995 to 2004,2005) study. Vertical and horizontal distribution of bolls on a cotton plant was also determined in 2003,2004 and 2004,2005. At the end of year 11, soil samples were collected and analysed for soil organic carbon content, water-stable aggregates (%), and mean weight diameter. Averaged over 3 years, an additional 94 kg seed cotton ha,1 was produced in the organic over the modern method of cultivation and the difference was significant. The year × treatment interaction was significant. Seed cotton yield in the organic plots was significantly greater than the modern method of cultivation plots in 2003,2004 because of a well-distributed normal rainfall and low pest incidence. The main stem nodes 13,22 accounted for the largest numbers of bolls present on the plant. Plants of the organic plots had significantly (37,71 %) more bolls on nodes 13,27 than those for the plants of the modern method of cultivation. Lateral distribution of bolls on a sympodial (fruiting) branch, was noticed up to fruiting point 11. However, treatment differences were not significant. With regard to fibre quality (length, strength, fineness and uniformity), differences between years were significant. Inferior quality fibre was produced in 2004,2005 because of delayed planting and early cessation of rain. On average, cotton grown under organic conditions compared with the modern method of cultivation had significantly better fibre length (25.1 vs. 24.0 mm) and strength (18.8 vs. 17.9 g tex,1). Soil samples of the organic plots had significantly greater C content, water-stable aggregates and mean weight diameter than the modern method of cultivation plots. Differences were restricted to the top layers (0,0.1 and 0.1,0.2 m). Yield benefits of growing cotton in an organic system over the modern method of cultivation are expected to be greater in years receiving normal rainfall and having low pest incidence. [source]


Strategies and Tools for Structure Determination of Natural Products Using Modern Methods of NMR Spectroscopy

CHEMISTRY & BIODIVERSITY, Issue 2 2005
Nadja Bross-Walch
First page of article [source]


New structures of four-phase oscillators obtained by strongly interweaving mono-phase limit-cycle oscillators

INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 4 2008
D. Yardeny
Abstract The present work is a part of our effort of developing multiphase oscillators. The particular system dealt with here is that of strongly nonlinearly coupled four oscillators that form a multiphase source. Such sources possess potential applications in power electronics, in phased-array antennas, and in modern methods of modulation and especially in demodulating multi-phased modulated signals. The present system can be interpreted as embracing four two-phase oscillators. Nevertheless, as a result of the strong coupling, the second state equation of each oscillator merges with the first equation of the following oscillator. The resulted four-phase source is, therefore, represented by merely four state equations. The applications related to communications (especially those related to receivers) may be susceptible to the noise performance of the source. We believe that the presently suggested system, which relies on strong coupling of oscillators, is advantageous in its noise performance in comparison to more straightforward recently described multiphase sources, which incorporate loosely coupled oscillators. Copyright © 2007 John Wiley & Sons, Ltd. [source]


A brief review of the status, distribution and biology of wild Asian elephants Elephas maximus

INTERNATIONAL ZOO YEARBOOK, Issue 1 2006
R. SUKUMAR
The Asian elephant Elephas maximus is distributed discontinuously across the Asian continent. The total wild population is 38 500-52 500, with a further c. 16 000 in captivity, the majority of which are in range countries. India has 60% of the global population of wild Asian elephants. The species has a multi-tiered social system with ,, living in matriarchal groups of five to 20 individuals that interact with other family units in the area. Adult ,, live alone or in small, temporary groups with weak social bonds. Asian elephants are megaherbivores that spend 12-18 hours per day feeding, and they eat browse and plants depending on availability and season. Home-range size is dependant on the availability of food, water and shelter in the region. Loss and fragmentation of habitat, human-elephant conflicts and poaching are the greatest threats to the species. Asian elephants are managed using traditional and modern methods but progress still needs to be made to improve welfare, training and breeding for these animals. [source]


Thermal stability of vaccines

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2003
Duane T. Brandau
Abstract Worldwide vaccination programs against infectious diseases and toxins are estimated to save approximately 3 million lives yearly. Tragically, however, another 3 million individuals (primarily children) die of vaccine-preven diseases. A significant portion of this problem results from the thermal instability of many of the currently used vaccines. This review argues that modern methods of physical and chemical analysis permit for the first time characterization of the degradative pathways of thermally labile vaccines. A rigorous description of these pathways permit a more rational and systematic approach to the stabilization of vaccines. A direct result of the replacement of currently employed, primarily empirical, approaches to vaccine stabilization with a more molecular-based methodology should be the development of more universally available vaccinations against life-threatening diseases. This has the potential to have a dramatic impact on world health. © 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 92:218,231, 2003 [source]


Construction and characterization of a recombinant plasminogen activator composed of an anti-fibrin single-chain antibody and low-molecular-weight urokinase

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2004
C. E. Hagemeyer
Summary.,Background: Targeting of plasminogen activators to the fibrin component of a thrombus by antibodies directed against human fibrin can enhance their thrombolytic potency and clot specificity. Objectives: To overcome the disadvantages of chemical conjugation, we investigated whether the recombinant fusion of a single-chain antibody and a plasminogen activator results in an active bifunctional molecule that might be useful as a therapeutic agent. Methods: The cDNA of low-molecular-weight single-chain urokinase-type plasminogen activator, comprising amino acids Leu144-Leu411 (scuPALMW), was cloned from human endothelial cells and fused to a single-chain antibody specific for the 7 N-terminal amino acids (,15,22) in the ,-chain of human fibrin (scFv59D8). The fusion protein was purified using affinity chromatography with the ,15,22 -peptide of human fibrin. Results: Purified scFv59D8,scuPALMW migrated as a 60-kDa band, which is consistent with a molecule composed of one scFv59D8 and one scuPALMW moiety. Both functions of the fusion molecule, fibrin-specific binding and plasminogen activation, were fully preserved. In human plasma clots, thrombolysis by scFv59D8,scuPALMW is significantly faster and more potent compared with the clinically used urokinase. Conclusions: ScFv59D8,scuPALMW constitutes a new recombinant chimeric plasminogen activator with a significantly enhanced thrombolytic potency and relative fibrin selectivity, that can be produced with modern methods at low cost, large quantities and reproducible activity in Escherichia coli. [source]


The iR drop , well-known but often underestimated in electrochemical polarization measurements and corrosion testing,

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 6 2006
W. Oelßner
Abstract At first sight the problem of the iR drop and its compensation in electrochemical polarization measurements seems to have only minor significance, but it has actually troubled electrochemists and corrosion scientists for more than a hundred years. For reducing the iR drop in the electrochemical cell, its computation, experimental determination and numerical or automatic electronic compensation numerous scientific and experimental work has been carried out and appropriate suggestions were submitted. These efforts led to commercially available potentiostats with sophisticated facilities for automatic iR compensation. Nevertheless, to date these possibilities have been utilized with a certain hesitancy. Many users underestimate the iR drop, regarding it often merely as a marginal problem, which only has to be taken into account in experiments with very high currents or extremely low conductivity of the electrolyte. Furthermore, there are also doubts and prejudices regarding modern methods of iR compensation, resulting from previous unpleasant experiences or reports on failed experiments with inappropriate equipment or imperfect methods. Reduction or automatic compensation of the iR drop is necessary more frequently than generally assumed and also in most cases possible. On the other hand the application of the different methods is still not completely uncomplicated and requires special experimental experience and care. The aim of the present work is it therefore to give a comprehensive retrospective overview of the ohmic drop problem and the relevant activities to overcome it. [source]


Tradeoffs and sexual conflict over women's fertility preferences in Mpimbwe

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2009
Monique Borgerhoff Mulder
There are two principle evolutionary models for why women reduce their fertility, which can be used to explain the modern demographic transition. The first derives from optimality theory (specifically the "quantity-quality" tradeoff hypothesis), and the second from models of biased cultural transmission ("prestige bias" and "kin influence" hypotheses). Data on family planning preferences collected in 1996 and 1998 in a rural African village (in Mpimbwe, Tanzania) are used to test predictions derived from each hypothesis and show that both "quantity-quality" tradeoffs and biased cultural transmission underlie Pimbwe women's decisions. Reproductive decisions, however, are not made in a vacuum. Men and women's ideal family sizes often differ, and sexual conflict is particularly likely to affect a woman's success in limiting her family size. Pimbwe women's reproductive output between the initial family planning survey in 1996 and the most recent demographic survey (2006) is analyzed in relation to both the woman's preferences to limit her family and her exposure to husbands and husbands' kin. Despite wide differences in desired family sizes between men and women the extent of sexual conflict in this population is restricted to husbands and wives, and affects not a woman's use or planned use of modern contraception but her success in employing such methods effectively. There is also some evidence that a woman's mother and her kin assist in the use and effective use of modern methods, offering a prevailing force to the high-fertility objectives of the husband. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source]


What to Do about Missing Values in Time-Series Cross-Section Data

AMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 2 2010
James Honaker
Applications of modern methods for analyzing data with missing values, based primarily on multiple imputation, have in the last half-decade become common in American politics and political behavior. Scholars in this subset of political science have thus increasingly avoided the biases and inefficiencies caused by ad hoc methods like listwise deletion and best guess imputation. However, researchers in much of comparative politics and international relations, and others with similar data, have been unable to do the same because the best available imputation methods work poorly with the time-series cross-section data structures common in these fields. We attempt to rectify this situation with three related developments. First, we build a multiple imputation model that allows smooth time trends, shifts across cross-sectional units, and correlations over time and space, resulting in far more accurate imputations. Second, we enable analysts to incorporate knowledge from area studies experts via priors on individual missing cell values, rather than on difficult-to-interpret model parameters. Third, because these tasks could not be accomplished within existing imputation algorithms, in that they cannot handle as many variables as needed even in the simpler cross-sectional data for which they were designed, we also develop a new algorithm that substantially expands the range of computationally feasible data types and sizes for which multiple imputation can be used. These developments also make it possible to implement the methods introduced here in freely available open source software that is considerably more reliable than existing algorithms. [source]


Local Recurrence of Breast Cancer after Skin-Sparing Mastectomy Following Core Needle Biopsy: Case Reports and Review of the Literature

THE BREAST JOURNAL, Issue 3 2006
Juan Luis Uriburu MD
Abstract: The latest advances in diagnostic and therapeutic procedures for breast cancer have provided valuable technological breakthroughs. Yet the long-term consequences of these modern methods are still quite unclear. Such is the case for stereotactic or ultrasound-guided histologic needle biopsy and skin-sparing mastectomy. We report on three patients who presented with multicentric breast cancer diagnosed by stereotactic needle biopsy and treated by skin-sparing mastectomy. All three patients developed recurrence at the core needle entry site. Records of 58 patients with breast cancer who were treated by skin-sparing mastectomy followed by immediate reconstruction (with transverse rectus abdominis muscle [TRAM] flap or tissue expander) at the Breast Diseases Division of Buenos Aires British Hospital between December 1999 and December 2003 were reviewed retrospectively. Eleven of these patients were diagnosed by histologic needle biopsy. The mean follow-up was 28 months (range 5,60 months). Three (skin or subcutaneous) local recurrences at the needle entry site, diagnosed in a mean time of 23.6 months (16, 22, and 23 months), were reported. The three patients underwent complete resection with clear margins, radiation therapy to the "neobreast," and tamoxifen. All three patients are disease free with a mean postrecurrence follow-up of 24.3 months (30, 23, and 22 months). Based on the evidence of displacement of tumor cells and the potential nonresection of such tumor seeding at the time of skin-sparing mastectomy, as well as the poor probability of postoperative radiation therapy, we recommend surgical resection of the needle biopsy tract, including the dermal entry site, at the time of mastectomy. [source]


SOLUTIONS FOR EXTERIOR ORIENTATION IN PHOTOGRAMMETRY: A REVIEW

THE PHOTOGRAMMETRIC RECORD, Issue 100 2002
Pierre Grussenmeyer
Abstract The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term "exterior orientation" of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects. This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first. a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point-bused methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line-based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry. Résumé La détermination de l'attitude, de la position et des caractéristiques intrinsèques de la chambre photographique constitue un problème fondamental en photogrammétrie. Il se résume à la détermination des paramètres de l'orientation de la chambre de prise de vue (paramètres des orientations externe et interne), ainsi qu'à la détermination des coordonnées 30 des points de l'objet. L'orientation externe se rapporte à la détermination de la position et de l'orientation d'une chambre par rapport à un système externe de coordonnées. Différentes méthodes peuvent être utilisées pour calculer les éléments dorientation externe d'une photo, d'un couple ou de plusieurs photos. Le calcul de l'orientation peut être réalisé par étapes (par exemple les orientations relative et absolue) mais les méthodes simultanées (la compensation par faisceaux par exemple) sont actuellement proposées dans la plupart des logiciels. Plusieurs méthodes ont aussi été développées pour l'orientation d'images isolées. Ells sont basées en général sur les caactéristiques géométriques et topologiques des objets photographiés. Dans cet article on présente un ensemble de méthodes classiques et modernes pour la détermination des paramètres de l'orientation externe, certaines d'entre elles étant téléchargeables sous la forme d'applications sur Internet. Les méthodes présentées sont classées en trois groupes principaux. Le premier groupe contient une sélection de méthodes approximatives utilisées d'habitude quand une grande précision n'est pas exigée, ou encore pour calculer des vuleurs approchées des paramètres extrinsèques requises pour les méthodes itératives rigoureuses. Dans le deuxième groupe, on rappelle brièvement les jondements des méthodes basées sur les conditions photogrammétriques fondamentales (la colinéarité, la coplanéité et la coangularité). Dans ce groupe, les méthodes basées sur l'extraction des points ou des lignes sont également abordées. Le troisième groupe traite des méthodes d'orientation basées sur les contraintes et les concepts de la géométrie projective, de plus en plus utilisées par les photogrammètres. Le dernier paragraphe se rapporte aux méthodes destinées à automatiser le calcul de l'orientation externe en photogrammétrie aérienne. Zusummenfussung Die Bestimmung der Neigung, der Position und den geometrischen parametern der Kamera wird als das fundamentale Problem der Photogrammetrie angesehen. Es kann zusammenfassend sowohl als die Bestimmung der Parameter der inneren und äusseren Orientierung der Kamera angesehen werden, als auch als die Bestimmung von 3D Koordinaten von Objektpunkten. Der Ausdruck "äussere Orientierung" eines Bildes bezieht sich auf die Lage und Orientierung bezogen auf ein äusseres (Objektraum-) Koordinatensystem. Es können verschiedene Methoden angewandt werden, um die Parameter von einem, zwei oder mehreren Bildern zu bestimmen. Die orientierung kann in Schritten erfolgen, was als Relative und Absolute Orientierung bezeichnet wird, aber auch simultane Methoden, wie die Bündelausgleichung, sind in vielen Softwarepaketen implementiert. Es wurden auch Methoden für die Orientierung von Einzelbildern entwickelt, die geometrische und topologische Eigenschaften der abgebildeten Objekte nutzen. In diesem Beitrag wird Beitrag wird eine Studie klassischer und moderner Methoden der Photogrammetrie zur Bestimmung der Parameter der äßeren Orientierung vorgestellt, wovon einige in Softwarepaketen zur Verfügung stehen, die von praktischen Beispielen im Internet ergänzt werden. Die untersuchten Methoden werden in drei Hauptgruppen eingeteilt. In einer ersten Gruppe werden Näherungslösungen vorgestellt, die für Anwendungen mit geringen Genauigkeitsanforderungen geeignet sind. Diese Methoden werden ansonsten für die Näherngswertberechunggen für iterative Prozesse verwendet. IN der zweiten Gruppe werden zuerst die punktbasierten Standardmethoden vorgestellt, die von Bedingungen zur Kollinearität. Koplanarität und Kowinkligkeit abgeletet sind. Danach folgen linienbasierte Ansätze. Die dritte Gruppe umfasst Orientierungsmethoden, die auf Zwangsbedingungen und auf Konzepte der projektiven Geometrie aufbauen, die für Photogrammeter von zunehmendem Interesse sind, Im letzten Abschnitt wird eine Zusammenfassung existierender Strategien für eine automatische äussere orientierung in der Luftbildphotogrammetrie gegeben. [source]


Solutions for Exterior Orientation in Photogrammetry: A Review

THE PHOTOGRAMMETRIC RECORD, Issue 100 2002
Pierre Grussenmeyer
The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term "exterior orientation"of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects. This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first, a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point,based methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line,based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry. [source]


Intersectoral Linkages and Key Sectors in China, 1987,1997

ASIAN ECONOMIC JOURNAL, Issue 2 2004
B. Andreosso-O'Callaghan
Since the pioneering work by Rasmussen and others in the 1950s, alternative measures of linkages have been developed, with the aim of examining the interdependence in production structures and in identifying key sectors in an economy. Our study proposes a comparative analysis of traditional and modern methods, by applying them to the case of China between 1987 and 1997. It finds that backward and forward linkages have generally increased in China, denoting an increase in intersectoral interdependence, with some sectors (e.g. agriculture, food, textiles and chemicals) being dominant in this process. With regard to the identification of key sectors, hypothetical extraction methods provide superior results compared with traditional methods. Agriculture, textiles, chemicals, building materials, primary metals, machinery, commerce and other services are all recognized as being the key sectors by both the total linkage and pure linkage methods. [source]


Dissecting galaxies with quantitative spectroscopy of the brightest stars in the Universe

ASTRONOMISCHE NACHRICHTEN, Issue 5 2010
R.-P. KudritzkiArticle first published online: 20 MAY 2010
Abstract Measuring distances to galaxies, determining their chemical composition, investigating the nature of their stellar populations and the absorbing properties of their interstellar medium are fundamental activities in modern extragalactic astronomy helping to understand the evolution of galaxies and the expanding universe. The optically brightest stars in the universe, blue supergiants of spectral A and B, are unique tools for these purposes. With absolute visual magnitudes up to MV , -9.5 they are ideal to obtain accurate quantitative information about galaxies through the powerful modern methods of quantitative stellar spectroscopy. The spectral analysis of individual blue supergiant targets provides invaluable information about chemical abundances and abundance gradients, which is more comprehensive than the one obtained from HII regions, as it includes additional atomic species, and which is also more accurate, since it avoids the systematic uncertainties inherent in the strong line studies usually applied to the HII regions of spiral galaxies beyond the Local Group. Simultaneously, the spectral analysis yields stellar parameters and interstellar extinction for each individual supergiant target, which provides an alternative very accurate way to determine extragalactic distances through a newly developed method, called the Flux-weighted Gravity,Luminosity Relationship (FGLR). With the present generation of 10 m-class telescopes these spectroscopic studies can reach out to distances of 10 Mpc. The new generation of 30 m-class telescopes will allow to extend this work out to 30 Mpc, a substantial volume of the local universe (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Value of post-nasal space biopsy in patients with adult onset serous otitis media

CLINICAL OTOLARYNGOLOGY, Issue 3 2006
A.H. Sadr
Background. Otitis media with effusion (OME) is common in children but this is not the case in adults. In adults it can be associated with nasopharyngeal neoplasms (NPN). It is accepted practice in the UK to biopsy the posterior nasal space (PNS) to rule out neoplasms. We believe this routine practice is no longer justified in view of modern methods of examination of PNS. Aims and objectives. To identify the incidence of NPN in adults with otitis media with effusion without any other signs and symptoms suggestive of NPN. We also identified the presenting symptoms and signs of all patients who were diagnosed with NPN during the study period. Methods. This is a retrospective study of 158 adult onset otitis media who had a posterior nasal space biopsy performed. The patients with positive and negative biopsy results were analysed for their presenting signs and symptoms. Results. Only 58 patients had OME as the sole presentation. The rest had other signs or symptoms in addition to OME. All patients with OME as the sole presentation had negative biopsy results and all patients with a positive biopsy result for NPN had other symptoms or signs in addition to OME. Conclusions. The role of PNS biopsy in adults with isolated OME seems to be questionable in view of the limited information it provides. This may be due to wider use of endoscopes which enable us to detect small abnormalities in PNS. [source]