bluuebunny/crossref_metadata_2025 huggingface dataset:
Future expectations of Brasilian street youth
Authors: Raffaelli Marcela , Koller Silvia H.
Published: March 2005

Future expectations of youth surviving on the streets of Porto Alegre, Brasil, were examined. The sample consisted of 35 boys and 34 girls aged 10–18 (M age 14.4) who participated in a sentence completion task and semi‐structured interviews. Responses to two incomplete sentences regarding the future revealed a mismatch between hoped‐for and expected events. When completing the sentence, “In the future, I hope…” the majority of youth gave optimistic (but generally non‐specific) responses. In contrast, the sentence “For me, the future…” elicited more pessimistic responses. Few gender or age‐related differences emerged. Findings are discussed in light of prior research with general populations of adolescents as well as studies of street youth. Taken as a whole, results suggest that life on the street shapes and constrains how youth see their futures. Implications of the findings for policy makers and practitioners are addressed.
Inflamm‐ageing and lifelong antigenic load as major determinants of ageing rate and longevity
Authors: De Martinis Massimo , Franceschi Claudio , Monti Daniela , Ginaldi Lia
Published: March 2005

Immunosenescence is the consequence of the continuous attrition caused by chronic antigenic stress. The most important characteristics of immunosenescence (accumulation of memory and effector T cells, reduction of naive T cells, shrinkage of T cell repertoire, reduction of the immunological space) are compatible with this assumption. Immunosenescence can be taken as proof that the beneficial effects of the immune system, devoted to the neutralization of harmful agents early in life, become detrimental late in life, in a period not foreseen by evolution. This perspective could explain the mechanisms of the ageing process as well as the pathogenesis of age‐related diseases.
Intermittency analyses on the SIERRA measurements of the electric field fluctuations in the auroral zone
Authors: Tam Sunny W. Y. , Chang Tom , Kintner Paul M. , Klatt Eric
Published: March 2005

We perform intermittency analyses on the electric field data obtained by the SIERRA sounding rocket in the auroral zone. The electric field fluctuations are broadband, covering the extremely low‐frequency range with a power‐law relation, similar to the type of fluctuations commonly observed at various altitudes of the auroral region. Our preliminary analyses of the data based on the technique of probability distribution functions indicate that the electric field fluctuations are intermittent in the spacecraft frame. Using the methods of wavelet analyses and local intermittency measures, we determine the degree of intermittency of the fluctuations at various scales. It is found that the electric field fluctuations are more intermittent at smaller scales.
The lower positive charge center and its effect on lightning discharges on the Tibetan Plateau
Authors: Qie Xiushu , Zhang Tinglong , Chen Chengpin , Zhang Guangshu , Zhang Tong , Wei Wuzhou
Published: March 2005

Electrical characteristics of thunderstorms on the central Tibetan Plateau at an altitude of 4508 m have been studied. The evolution of surface electric (E) field and the E field changes produced by lightning flashes under a representative thunderstorm revealed a tripole charge structure with a larger‐than‐usual lower positive charge center (LPCC). The storms appear to begin with the lower dipole of a normal tripole structure, rather than with the upper dipole followed by the development of a weaker lower positive charge. The flash rate is quite low and the average value is usually 1 fl/min. The IC flashes were usually polarity‐inverted and occurred in the lower dipole. The large LPCC did not cause positive CG flashes to occur during the whole storm lifetime, and only negative CG flashes were observed in the late stage of the storm.
Diagrammatic Young projection operators for U(n)
Authors: Elvang Henriette , Cvitanović Predrag , Kennedy Anthony D.
Published: March 2005

We utilize a diagrammatic notation for invariant tensors to construct the Young projection operators for the irreducible representations of the unitary group U(n), prove their uniqueness, idempotency, and orthogonality, and rederive the formula for their dimensions. We show that all U(n) invariant scalars (3n−j coefficients) can be constructed and evaluated diagrammatically from these U(n) Young projection operators. We prove that the values of all U(n)3n−j coefficients are proportional to the dimension of the maximal representation in the coefficient, with the proportionality factor fully determined by its Sk symmetric group value. We also derive a family of new sum rules for the 3−j and 6−j coefficients, and discuss relations that follow from the negative dimensionality theorem.
Prediction of the critical micelle concentration in a lattice model for amphiphiles using a single-chain mean-field theory
Authors: Al-Anber Zaid A. , Bonet Avalos Josep , Mackie Allan D.
Published: March 2005

A single-chain mean-field theory is used to predict the properties of binary surfactant solutions including the critical micelle concentration (cmc). In particular, the cmc of two symmetric nonionic amphiphiles is calculated as a function of temperature in order to analyze the validity of the ideal mixing assumption, often employed in the mass action model. On comparing against literature Monte Carlo results for the same lattice model we find that although it is applicable at low temperatures and hence cmcs at low amphiphile concentrations, at higher temperatures it becomes necessary to correct for the nonideal mixing of the free chain–free chain bulk interaction. We find that a simplistic model taking into account only the repulsive interaction is sufficient to restore the excellent quantitative agreement found between a single-chain mean-field theory calculations and literature molecular simulation results at the low temperature limit.
Dipole moment and rovibrational intensities in the electronic ground state of NH3: Bridging the gap between ab initio theory and spectroscopic experiment
Authors: Yurchenko Sergei N. , Carvajal Miguel , Lin Hai , Zheng Jingjing , Thiel Walter , Jensen Per
Published: March 2005

We report theoretical values for the transition moments of an extensive set of vibrational bands in the electronic ground state of N14H3. For selected bands, we have further made detailed simulations of the rotational structure. The calculations are carried out by means of recently developed computational procedures for describing the nuclear motion and are based on a high-level ab initio potential energy surface, and high-level dipole moment surfaces, for the electronic ground state of NH3. The reported theoretical intensity values are compared to, and found to agree very well with, corresponding experimental results. It is believed that the computational method, in conjunction with high-quality ab initio potential energy and dipole moment surfaces, can simulate rotation-vibration spectra of XY3 pyramidal molecules prior to observation with sufficient accuracy to facilitate the observation of these spectra. By degrading the accuracy of selected elements of the calculations, we have also investigated the influence of customary approximations on the computed intensity values.
Electric conductivities of 1:1 electrolytes in liquid methanol along the liquid-vapor coexistence curve up to the critical temperature. III. Tetraalkylammonium bromides
Authors: Hoshina Taka-aki , Tanaka Kensuke , Tsuchihashi Noriaki , Ibuki Kazuyasu , Ueno Masakatsu
Published: March 2005

The molar conductivities of the dilute solutions of the tetraalkylammonium bromides have been measured in methanol along the liquid-vapor coexistence curve up to about 180°C. The limiting molar conductivities and the molar association constants have been obtained from the analysis of the concentration dependence of the conductivity. On the basis of the present data together with the literature ones, the validity of the Hubbard–Onsager (HO) dielectric friction theory [J. Hubbard, J. Chem. Phys. 68, 1649 (1978)] derived from the continuum model has been examined for the translational friction coefficients of the tetraalkylammonium ions in methanol in the density range of 0.8232gcm−3⩾ρ⩾0.5984gcm−3 and the temperature range of −15°C⩽t⩽180°C. At high densities and low temperatures, the observed friction coefficients of Me4N+ and Et4N+ are remarkably smaller than the prediction of the HO theory (where Me stands for methyl group and Et for ethyl group); this kind of limitation of the HO theory has not been recognized for smaller ions, and can be attributed to the loosening of the solvent structure closely related to the weak charge effect for the large ions. The negative deviation from the HO theory gradually disappears with decreasing density and increasing temperature, and the friction coefficients of Me4N+ and Et4N+ are explained by the HO theory reasonably well at low densities and high temperatures. For Pr4N+ and Bu4N+ (where Pr stands for propyl group and Bu for butyl group), the experimental friction coefficients lay in the validity range of the HO theory in all the conditions studied here; the breakdown of the continuum theory at low densities and high temperatures has not been observed in this work. The density dependences of the molar association constants of the tetraalkylammonium bromides are qualitatively explained by the Fuoss theory based on the continuum model.
On the interaction of electrons with betaine zwitterions
Authors: Zheng Weijun , Xu Shoujun , Radisic Dunja , Stokes Sarah , Li Xiang , Bowen Kit H.
Published: March 2005

Betaine is a permanent zwitterion. The molecular betaine anion has been generated in a hybrid, infrared desorption-electron photoemission source and its photoelectron spectrum recorded. The photoelectron spectrum of the betaine anion is characteristic of a dipole bound anion, and its vertical detachment energy was measured to be 0.29±0.03eV. Calculations by Rak, Skurski, and Gutowski [J. Chem. Phys. 114, 10673 (2001)] had found the betaine anion to be a dipole bound anion with a vertical detachment energy of 0.28 eV. We also measured the vertical detachment energy of deprotonated betaine to be ∼1.9eV.
Ultrafast all-optical switching in two-dimensional organic photonic crystal
Authors: Hu Xiaoyong , Liu Yuanhao , Tian Jie , Cheng Bingying , Zhang Daozhong
Published: March 2005

An all-optical switching with high switch efficiency is realized based on two-dimensional nonlinear photonic crystal made of polystyrene. The prism-film coupling method is used to couple energy of probe light into photonic crystal waveguide. High transmittance contrast of more than 60% is realized for the probe light. Time response of the optical switching is around l0 ps. The dynamical shifts of photonic gap induced by pump light are measured and analyzed in detail. The photonic gap shifts l0 nm under the excitation of 16.7GW∕cm2 pump intensity, which is in agreement with the theoretical predictions.
Effective tip radius in electrostatic force microscopy
Authors: Sacha G. M. , Verdaguer A. , Martínez J. , Sáenz J. J. , Ogletree D. F. , Salmeron M.
Published: March 2005

A method to determine the effective electrostatic tip radius of arbitrarily shaped conducting tips in atomic force microscopy is presented. The method is based on the finding that for conductive samples, the electrostatic force can be separated into two contributions: one from a constant background that depends only on the macroscopic shape of the tip (cone or pyramid and cantilever), and another that depends only on the radius of curvature of the tip apex. Based on a simple theoretical expression derived from the generalized image charge method, we show that the tip radius can be directly determined from experimental force-distance characteristics. For irregular tip shapes, we show that the measured tip radius is the average of two principal curvatures, in agreement with tip shape images obtained by scanning electron microscopy.
Creating all-angle negative refraction by using insertion
Authors: Zhang Xiangdong , Li Lie-Ming
Published: March 2005

The all-angle negative refraction (AANR) is generally very important to design a microsuperlens. However, it is usually absent from some two-dimensional (2D) photonic crystals (PCs). In this letter, we present a method to create and enlarge the AANR region by using insertion. For some 2D dielectric PC systems without the AANR, the AANR region can be created by adding a fraction of a metallic component to the center of each dielectric cylinder. At the same time, the AANR region can be enlarged by adjusting the size of the metal cylinder. To illustrate this phenomenon, the microsuperlens is designed and numerically demonstrated.
Temperature effect on carrier transport characteristics in SrTiO3−δ/Si p-n heterojunction
Authors: Guo Haizhong , Huang Yanhong , Jin Kuijuan , Zhou Qingli , Lu Huibin , Liu Lifeng , Zhou Yueliang , Cheng Bolin , Chen Zhenghao
Published: March 2005

A p-n junction has been fabricated by depositing an electron-doped (n-) SrTiO3−δ film on a hole-doped (p-) Si substrate with a two atomic-layers thickness epitaxial SrO buffer layer using laser molecular beam epitaxy technique. Good crystallinity and smooth surface of SrTiO3−δ were confirmed by reflection high-energy electron diffraction and x-ray diffraction. The junction shows good rectifying behavior at room temperature, and strong temperature dependence of current-voltage (I-V) properties in the range of 200–300 K. These results present potential applications in future microelectronic devices based on growing perovskite oxide thin films on conventional semiconductors.
Observation of negative refraction and negative phase velocity in left-handed metamaterials
Authors: Aydin Koray , Guven Kaan , Soukoulis Costas M. , Ozbay Ekmel
Published: March 2005

We report the transmission characteristics of a two-dimensional (2D) composite metamaterial (CMM) structure in free space. At the frequencies where left-handed transmission takes place, we experimentally confirmed that the CMM structure has effective negative refractive index. Phase shift between consecutive numbers of layers of CMM is measured and phase velocity is shown to be negative at the relevant frequency range. Refractive index values obtained from the refraction experiments and the phase measurements are in good agreement.
Structures of two core subunits of the bacterial type IV secretion system, VirB8 from
Brucella suis
and ComB10 from
Helicobacter pylori
Authors: Terradot Laurent , Bayliss Richard , Oomen Clasien , Leonard Gordon A. , Baron Christian , Waksman Gabriel
Published: March 2005

Type IV secretion systems (T4SSs) are commonly used secretion machineries in Gram-negative bacteria. They are used in the infection of human, animal, or plant cells and the propagation of antibiotic resistance. The T4SS apparatus spans both membranes of the bacterium and generally is composed of 12 proteins, named VirB1–11 and VirD4 after proteins of the canonical
Agrobacterium tumefaciens
T4SS. The periplasmic core complex of VirB8/VirB10 structurally and functionally links the cytoplasmic NTPases of the system with its outer membrane and pilus components. Here we present crystal structures of VirB8 of
Brucella suis
, the causative agent of brucellosis, and ComB10, a VirB10 homolog of
Helicobacter pylori
, the causative agent of gastric ulcers. The structures of VirB8 and ComB10 resemble known folds, albeit with novel secondary-structure modifications unique to and conserved within their respective families. Both proteins crystallized as dimers, providing detailed predictions about their self associations. These structures make a substantial contribution to the repertoire of T4SS component structures and will serve as springboards for future functional and protein–protein interaction studies by using knowledge-based site-directed and deletion mutagenesis.
A mechanism for the association of amino acids with their codons and the origin of the genetic code
Authors: Copley Shelley D. , Smith Eric , Morowitz Harold J.
Published: March 2005

The genetic code has certain regularities that have resisted mechanistic interpretation. These include strong correlations between the first base of codons and the precursor from which the encoded amino acid is synthesized and between the second base of codons and the hydrophobicity of the encoded amino acid. These regularities are even more striking in a projection of the modern code onto a simpler code consisting of doublet codons encoding a set of simple amino acids. These regularities can be explained if, before the emergence of macromolecules, simple amino acids were synthesized in covalent complexes of dinucleotides with α-keto acids originating from the reductive tricarboxylic acid cycle or reductive acetate pathway. The bases and phosphates of the dinucleotide are proposed to have enhanced the rates of synthetic reactions leading to amino acids in a small-molecule reaction network that preceded the RNA translation apparatus but created an association between amino acids and the first two bases of their codons that was retained when translation emerged later in evolution.
Women's Missionary Societies
Authors: Kent Eliza F.
Published: March 2005

This chapter examines the extent to which evangelical Christianity empowered women missionaries and enabled them to challenge the patriarchal norms of missionary culture in India. It analyzes the conditions in the United States and Britain that gave rise to the women’s missionary project, and the theological dispositions shared by male and female missionaries of the time. It then compares the styles of two women missionaries who were motivated by two varieties of Protestant Christianity: Amy Carmichael, the Keswick missionary initially attached to the Church of England Zenana Missionary Society in Tirunelveli; and Eva Swift, a missionary sent by the American Board of Commissioners for Foreign Missions to the American Madurai Mission.
Motherhood and the Home: Indian Christian Domesticity
Authors: Kent Eliza F.
Published: March 2005

This chapter argues that Protestant Christian women in the West were intrigued by the purdah system in India, partly because it resonated with patterns of gender segregation with which they were familiar. The aspects of the gender ideology embodied in purdah that were retained in the new hybrid discourse of femininity resulting from the interaction between Protestant missionaries and representatives of elite Indian culture are examined. This is followed by an analysis of the history of the zenana missions, tracking the changes in the strategies for the reform of Indian women and their relationship to the Indian home as the focus of missions shifted from elite to low-caste women.
Civilization and Sexuality: Indian Christian Marriage
Authors: Kent Eliza F.
Published: March 2005

This chapter examines representations of conjugality produced in three different textual genres: the administrative records of the Madras Presidency; the literature produced by educated, urban, high-caste Indian Christians; and the tracts of the first independent Christian church in south India. Marriage was an outward sign of the quality of the inner transformations of Indian Christians, with different groups adopting different forms of marriage. While the elite Satthianadhans embraced a form of marriage modeled after Western forms, the founder of the Hindu Christian Church Rev. Arumai Nayakam Sattampillai advocated a martial form of marriage drawn from conservative elements of Indian tradition.
Convictions of the Soul
Authors: Nepstad Sharon Erickson
Published: March 2005

This book examines the Central American solidarity movement based on the cultural-agency approach. It also explores the challenges of organizing at the transnational level. People of faith were at the center of this movement, determined to change President Reagan’s foreign policy towards Nicaragua, El Salvador, and Guatemala. To achieve this goal, some petitioned Congress to stop aid to those responsible for human rights violations in the region. Many attended protests, marches and commemorative vigils.
Rituals and Emotional Rejuvenation
Authors: Nepstad Sharon Erickson
Published: March 2005

The Central American solidarity movement began to subside in the late 1980s as the countries in the region signed peace accords and military regimes lost power. However, there often remains a group of activists who continue to organize. Their biggest challenge is sustaining commitment to a movement that has lost momentum, with the prevailing view that protest is no longer necessary or effective. In the early 1990s, Father Roy Bourgeois successfully launched a campaign that kept solidarity activism alive.
Italy: The Faded Beacon and the Populist Surge
Authors: Ignazi Piero
Published: March 2005

This chapter explores the evolution of fascism in Italy. Fascism found its complete and lasting realisation in inter-war Italy from 1922 until 1943-45. No other extreme right party succeeded in post-war Italy. In the 1990s, a new party, the (Lega Nord) Northern League, has been credited with anti-system and right-extremist credentials.
Germany: The Spectre That Never Materialized
Authors: Ignazi Piero
Published: March 2005

This chapter examines the development of right-extremism in Germany. It identifies a third wave of right extremism, which reflects the latent needs of a society emerging from structural/economic and value modification. The emergence of a ‘new axis of conflict,’ representing a non-material agenda ranging from national identity to authoritarianism, from xenophobia to moral traditionalism, has provided a non-ephemeral base on consent for the extreme right. Despite the failure of the extreme right in the electoral arena, it is still present in street level activity, especially in the East.
Belgium: Right Extremism and Ethnic Nationalism
Authors: Ignazi Piero
Published: March 2005

This chapter explores the extreme right in Belgium. Both the Walloon and Flemish extreme right parties advocate a strong state with a harsher penal code, ‘law and order’ enforcement, restoration of traditional moral values and sex roles, and radical opposition to the political system and established parties. However, these parties maintain different views on the issue of ethnic nationalism, and both refuse to be labelled as ‘fascist.’
Democracy and Public Management Reform
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The two major political institutions acting in modern democracies–civil society and the state–assume new ways of relating among themselves, thereby producing new democratic governance. Discusses two aspects of this global change: the republican democracy that is emerging in the twenty-first century and public management reform. The objective of this reform is to increase state capacity, to create a ‘strong state’: able to produce representative and accountable democratic governments; able to protect civil rights and assure markets, and so liberal; able to promote social justice, and so social; able to resist corruption and rent seeking, and thus republican. Starts from the assumption that, just as only a strong civil society may guarantee democracy, only a strong state may assure competitive markets. Defines the words ‘nation-state’ (or ‘country’), state, and civil society.
Public Management Reform in Practice
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

Public management reform started in Great Britain, New Zealand, and Australia in the 1980s. In the US, the reform occurred mainly at local level, but the National Performance Review Program ‘Reinventing Government’. Public management reform also advanced in the Scandinavian countries and in the Netherlands. In Canada, the reform had to await a major fiscal adjustment programme that lasted most of the 1990s, but it is today under way. In Italy, it is beginning. Among the developing countries, only in Brazil and Chile has public management reform gained ground. It is lagging behind in countries such as Germany, France, and Japan, where bureaucratic administration was more successfully and formally established.
Managing from the Strategic Core
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The state is politically and administratively managed from the strategic core. Discussion is limited to the strategic plan that each organization is required to have, and the managerial strategy that each public management reform will choose. Although relevant as major management tools, does not discuss information technology, the Internet, and personnel. Among the management strategies developed in the private sector, quality control is the one that most management reforms in the OECD countries and in Brazil have been adopting. This is because, in the evaluation process, it is not limited to the profit objective but sets a number of other criteria, which, being qualitative, adapt well to public management. On the other hand, management contracts are another essential tool for public management reform.
Consciousness and Space
Authors: McGinn Colin
Published: March 2005

The subject of this chapter is the relation of consciousness to space, and it is suggested that reductionism about consciousness needs must involve a new conception of space. Experiences are non-spatial and as such are even in principle unperceivable; they are thus quite unlike the posits of physics, unobservables postulated as the best explanation of data. The problem of how something non-spatial could arise out of a universe composed merely of spatially located matter obeying the laws of physics under the influence of natural selection (‘the space problem’) is discussed. Dualism, which denies that mind did emerge from matter, is one solution; classic materialism, which denies that consciousness is inherently spatial (though that is how we conceive of it), is another. Both positions are unattractive, and it is proposed that a solution to the mind-body problem requires a conception of space radically different from the one we have, though, in the light of Strawson’s arguments that our experience is inherently spatial, it is perhaps one that we cannot ever achieve.
Ethics Without Principles
Authors: Dancy Jonathan
Published: March 2005

The book is in three parts. The first part discusses the nature of contributory reasons, set in the more general context of normative theory. It introduces and defends a distinction between reasons and enabling conditions, and considers some other roles that considerations that are morally relevant but not reasons might play. It also asks which meta-ethical positions have the tools necessary to capture the role of contributory reasons. The second part uses these results to argue for holism in the theory of reasons, and to construct an argument from that holism to particularism in ethics, which is characterised as the view that moral thought and judgement in no way depend on a suitable provision of moral principles. There is also a chapter on the epistemology of moral reasons, from a particularist point of view. The third part is concerned with the theory of value, in particular with a form of holism there which is analogous to holism in the theory of reasons. There is a final chapter on holism in the theory of choice.
Dropping the Catch
Authors: Dancy Jonathan
Published: March 2005

Argues that various standard meta-ethical positions have great difficulty in understanding the notion of a contributory reason, being largely formulated to deal with overall oughts. These positions are those of M. Smith, A. Gibbard, F. Jackson, B. Brandom, and I. Kant.
Knowing Reasons
Authors: Dancy Jonathan
Published: March 2005

A chapter on moral epistemology. Asks what, for the particularist, will count as a basic moral fact. Considers the modal status of such facts, arguing that they are contingent, but known a priori. Claims that this position is neither foundationalist nor coherentist. Ends by considering various suggestions that particularism cannot avoid some form of general scepticism in ethics.
Are there Organic Unities?
Authors: Dancy Jonathan
Published: March 2005

Argues against G. E. Moore’s conception of organic unities, attempting to replace it with a conception more amenable to particularism. Considers the possibility of a form of default value acceptable to particularism. Ends by contrasting the views expressed here with those of Kagan.
Introduction: Walking the Tightrope
Authors: Kuper Andrew
Published: March 2005

In the face of globalization, an international political system based on states is unable to meet daunting political challenges that confront our world. Is it possible to develop a global order that would enable more justifiable and effective rule for the world’s people? In particular, can the principles and practices of justice and representative democracy be extended, to answer this challenge, beyond the state contexts for which they were devised? This book argues that we should end our dubious romance with the nation-state in favour of a multi-form global system called Responsive Democracy. To this end, the book presents core components of (a) a theory of global justice that arises out of a critique of the influential political philosophy of John Rawls; (b) a theory of democratic representation that constitutes an alternative to the approach taken by Jurgen Habermas and his deliberative democratic followers; and (c) a theory of how political and moral ideals that are necessarily framed in abstract terms can help orient practice in messy, non-ideal conditions. Together, these three currents of this text form a novel approach to global justice and democracy. The concrete implications of this approach to constitutionalism, institutional design, and politics will be explored for four leading global institutions.
Global Justice
Authors: Kuper Andrew
Published: March 2005

Develops a cosmopolitan theory of global justice, in critical dialogue with John Rawls’s The Law of Peoples. Kuper argues that Rawls has begged some of the central questions of global justice by adopting a ‘thin statist’ conception of legitimate global order. Thus, Rawls effectively supports a system of unitary nation-states with limited sovereignty, while Kuper rejects this idea in favour of multi-level and multi-type political institutions. Similarly, Rawls disavows free speech and democratic rights at the global level, while Kuper establishes that they are fundamental requirements of global justice. Kuper then proposes a new notion of ‘plurarchic sovereignty’ governed by Principles of Democracy and Subsidiarity. Important practical implications are demonstrated in three areas: economic development, the rules of engagement with illiberal states, and the use of force in humanitarian intervention.
Prevalence of primary breed‐related cataracts in the dog in North America
Authors: Gelatt Kirk N. , MacKay Edward O.
Published: March 2005

The objective of the study was to determine the prevalence of cataracts in dogs presented to veterinary medical teaching hospitals in North America between 1964 and 2003. A retrospective study of all dogs presented with cataracts to veterinary medical teaching hospitals in North America between 1964 and 2003 was conducted to determine cataract prevalence. The different decades, breeds, gender, and age at time of presentation with cataract were compared. The prevalence of dogs presented with cataract varied by decade and ranged from 0.95% (1964–73), 1.88% (1974–83), 2.42% (1994–2003), to 3.5% (1984–93). The total number of dogs presented with cataracts over the 40‐year period was 39 229. From 1964 to 2003 the prevalence of cataract formation in this patient population increased by about 255%. Fifty‐nine breeds of dogs were affected with cataracts above the baseline prevalence of 1.61% seen in mixed‐breed/hybrid dogs. The breeds with the highest cataract prevalence included: Smooth Fox Terrier (11.70%), Havanese (11.57%), Bichon Frise (11.45%), Boston Terrier (11.11%), Miniature Poodle (10.79%), Silky Terrier (10.29%) and Toy Poodle (10.21%). The breeds with the largest number of cataractous dogs during the entire four decades were the Boston Terrier (11.11%), Miniature Poodle (10.79%), American Cocker Spaniel (8.77%), Standard Poodle (7.00%), and Miniature Schnauzer (4.98%). Gender ratios of cataractous dogs seemed to affect limited breeds. Age of presentation with cataract diagnosis varied among several breeds. In the mixed‐breed/hybrid baseline population, cataract formation appeared to be age related with a higher frequency of cataract formation in dogs after 4–7 years. Cataract formation is one of the most prevalent eye diseases in the dog population, and in about 60 breeds of dogs the prevalence of cataract exceeds that of the baseline mixed‐breed/hybrid group. The prevalence of cataract is also influenced by age in most purebred dogs and affects 16.80% of the 7–15+‐year‐old mixed‐breed/hybrid dog population. Total and age‐related cataract prevalence in dogs seems very similar to that in man.
Combined transscleral diode laser cyclophotocoagulation and Ahmed gonioimplantation in dogs with primary glaucoma: 51 cases (1996–2004)
Authors: Sapienza John S. , Van Der Woerdt Alexandra
Published: March 2005

Objective To evaluate the combined diode laser cycloablation procedure and adjunctive Ahmed gonioimplant use in dogs with primary glaucoma.

Design Retrospective study.

Animals 48 dogs, 51 eyes with primary glaucoma.

Procedure Medical records from two large private clinical ophthalmology services were reviewed. Signalment, duration of glaucoma, gonioscopic evaluation, laser power and duration settings, immediate postoperative and final intraocular pressure and visual results, short and long‐term visual outcome, and surgical complications were recorded.

Results The age range of affected dogs was 3.0–14.0 years, with a mean age of 7.5 ± 2.6 years. Eleven pure breeds were represented, with the most common being the American Cocker Spaniel. The sex distribution was 22 neutered males, 1 intact male, 23 spayed females, and 2 intact female dogs. The right eye was affected in 33 cases, and the left eye in 18 cases. The average total joules, which was administered with the diode laser, was 109.6 ± 23.6 J.

 Immediate surgical complications included fibrin formation in the anterior chamber (15), corneal ulcers (4), hyphema (7), and focal retinal detachment (1). Long‐term complications included cataract formation (8 total, 2 of which were significant, vision‐threatening), elevated intraocular pressure (IOP) (6), unstable gonioimplant (1), and glaucoma recurrence (14). Additional surgeries performed on the eyes over the course of study included: intrascleral prosthesis (4), enucleation (1), resection of fibrotic scar tissue (5), and repeat laser cycloablation (8). The dogs were examined for a mean follow‐up time of 17.6 months (range: 2–83 months postoperatively). Twenty‐nine cases were followed greater than one year. Vision was maintained in 42/51 eyes (82%) in the immediate short‐term of this study.

 In all cases included in the study, good control of IOP was achieved in 39/51 (76%) of eyes, and IOP was poor or uncontrolled in 12/51 (24%) of eyes. Twenty out of 41 eyes (49%) maintained fair to excellent vision six months after surgery. Twelve months postoperative observations demonstrated that 12/29 (41%) of the eyes were still visual.

Conclusions In primary glaucoma, the combined procedure of laser diode cyclophotocoagulation and Ahmed valve implant was associated with return or maintenance of vision in 42/51 eyes (82%) in the immediate short‐term of this study, and a long‐term IOP control in 39/51 (76%) of the cases, with 12/29 eyes (41%) visual after 12 months.
Roughness Effects on the Mixing Properties in Open Channel Turbulent Boundary Layers
Authors: Tachie Mark F. , Bergstrom Donald J. , Balachandar Ram
Published: March 2005

This paper investigates the effects of surface roughness on the transport and mixing properties in turbulent boundary layers created in an open channel. The measurements were obtained on a smooth and two different types of rough surfaces using a laser Doppler anemometer. The results show that surface roughness enhances the levels of the turbulence kinetic energy, turbulence production, and diffusion over most of the boundary layer. The distributions of the eddy viscosity and mixing length are also strongly modified by surface roughness. Furthermore, the extent to which surface roughness modifies the turbulence structure depends on the specific geometry of the roughness elements.
Decay of Pressure and Energy Dissipation in Laminar Transient Flow
Authors: Brunone B. , Ferrante M. , Cacciamani M.
Published: March 2005

In the present paper, some peculiar characteristics of transient laminar flow are discussed. After presenting a review of the existing literature, attention is focused on transient energy dissipation phenomena. Specifically, results of both laboratory and numerical experiments are reported, the latter by considering one-dimensional (1D) along with two-dimensional (2D) models. The need of modifying a criterion for simulating unsteady friction proposed some years ago by one of the writers, and extensively used for water-hammer calculations, is pointed out. Differences between accelerating and decelerating flows as well as between transients in metallic and plastic pipes are also highlighted.
Werle´–Legendre Separation in a Hydraulic Machine Draft Tube
Authors: Mauri S. , Kueny J. L. , Avellan F.
Published: March 2005

The three-dimensional turbulent flow in a compact hydraulic machine elbow draft tube is numerically investigated for several operating conditions, covering an extended range around the best efficiency point. Comparisons with the experimental data are presented as validation. The interest is focused on the experimentally observed pressure recovery drop occurring near the best efficiency point. The flow is first analyzed locally by means of a topological analysis, then globally with an energetic approach. The study provides evidence for the role played by a Werle´–Legendre separation originating in the bend. The separation is due to the contrasting flow angles imposed by the blades, and the angle resulting from the secondary flow.
Frictional Resistance of Antifouling Coating Systems
Authors: Schultz Michael P.
Published: March 2005

An experimental study has been made to compare the frictional resistance of several ship hull coatings in the unfouled, fouled, and cleaned conditions. Hydrodynamic tests were completed in a towing tank using a flat plate test fixture towed at a Reynolds number ReL range of 2.8×106-5.5×106 based on the plate length and towing velocity. The results indicate little difference in frictional resistance coefficient CF among the coatings in the unfouled condition. Significant differences were observed after 287 days of marine exposure, with the silicone antifouling coatings showing the largest increases in CF. While several of the surfaces returned to near their unfouled resistance after cleaning, coating damage led to significant increases in CF for other coatings. The roughness function ΔU+ for the unfouled coatings showed reasonable collapse to a Colebrook-type roughness function when the centerline average height k=0.17Ra was used as the roughness length scale. Excellent collapse of the roughness function for the barnacle fouled surfaces was obtained using a new roughness length scale based on the barnacle height and percent coverage.
Analysis and Model-Based Control of Servomechanisms With Friction
Authors: Papadopoulos Evangelos G. , Chasparis Georgios C.
Published: March 2005

Friction is responsible for several servomechanism limitations, and their elimination is always a challenge for control engineers. In this paper, model-based feedback compensation is studied for servomechanism tracking tasks. Several kinetic friction models are employed and their parameters identified experimentally. The effects of friction compensation on system response are examined using describing function analysis. A number of control laws including classical laws, rigid body motion models, and friction compensation are compared experimentally in large-displacement tasks. Results show that the best response is obtained using a controller that incorporates a rigid body model and a friction model based on an accurate description of identified kinetic friction effects.
Designing Robust Repetitive Controllers
Authors: Osburn Andrew W. , Franchek Matthew A.
Published: March 2005

A method for designing repetitive feedback controllers using nonparametric frequency response plant models is developed. In comparison to the zero-phase-error (ZPE) controller (ASME J. Dyn. Syst. Meas. Control, 111, pp. 353–358), this method has the added benefit of providing improved transient performance when the plant inverse is unstable. In this controller design process, a connection is made between model uncertainty and the desired frequency response of the so-called q filter. Also, it will be shown that an optimal equiripple filter is useful when designing high-order q filters. The entire process was experimentally verified on an engine control application. A repetitive controller was used to determine the dynamic fueling requirements of a fuel injected, spark-ignition engine subjected to periodic changes in the throttle position. This fueling information is necessary when designing feedforward fueling algorithms.
Transient Air/Fuel Ratio Controller Identification Using Repetitive Control
Authors: Osburn Andrew W. , Franchek Matthew A.
Published: March 2005

Presented in this paper is a feedforward controller identification process for the transient fueling control of spark ignition (SI) engines. The objective of an SI fueling control system is to guarantee a prespecified air–fuel (A/F) ratio, despite changing driver demands commanded through the throttle. The controller identification process is based on standard system identification tools and is comprised of three steps. The first step involves the design and implementation of a repetitive feedback controller. Next, the engine is subjected to a prespecified periodic throttle motion for which the repetitive controller achieves precise A/F control as t→∞. Finally, using the engine speed, the mass air flow, and the fuel pulsewidth information during precise fueling conditions, the feedforward fueling controller is identified using standard parametric system identification tools. This identification process can be performed during engine warm-up, thereby enabling a rapid determination of the fueling requirements as a function of temperature. Experimental validation is provided on a 1999 Ford 4.6L V-8 fuel injected engine with sequential port injection.
On the Observability of Pressure in a Pneumatic Servo Actuator
Authors: Wu, Jianhui , Goldfarb, and Michael , Barth Eric
Published: March 2005

Pneumatic servo actuators are characterized by highly nonlinear dynamics from spool valve command to cylinder pressure and, as such, are well suited to the use of nonlinear control methods requiring measurement of the full state, such as sliding mode control. This paper investigates the possibility of eliminating the pressure measurement required for nonlinear control in lieu of a nonlinear pressure observer, based on measurement of the output motion. A nonlinear observability analysis is conducted that demonstrates that such a system loses local observability in several regions of the state space, thus rendering the system unobservable.
On the Origin of Torsional Vibrations in Hot Rolling Mills and a Possible Remedy
Authors: Belli P. , Bittanti S. , De Marco A.
Published: March 2005

Hot rolling mills suffer from severe torsional vibrations in particular working conditions (thin thickness). These vibrations are often explained as the result of an exogenous disturbance amplified by a resonance effect. In this paper, we show that these vibrations are in fact produced by the interaction between the kinematic chain and the phenomenon of the plastic deformation of the strip occurring in the roll bite. Precisely, the vibrations are the expression of an unstable limit cycle due to the combination of the dynamics associated with these two effects. Starting from this key observation, the vibration attenuation control problem is studied. First of all, by investigating the observability and controllability properties, it can be seen that there is a basic controllability problem in the standard configuration of the plant. To circumvent it, it is proposed to modify some mechanical characteristics so as to ensure the system controllability. Then a suitable active control system based on frequency domain concepts can be designed. The proposed control system neutralizes the torsional vibration, and therefore it allows one to preserve the system integrity while increasing plant efficiency and productivity.
Enhancing Controllability and Observability in Underactuated and Undersensed Systems Through Switching: Application to Vibration Control
Authors: Nudehi Shahin S. , Mukherjee Ranjan
Published: March 2005

Many dynamical systems use transducers that can function both as actuators and sensors. It is possible to continuously switch the functionality of the transducer elements in such systems and effectively use each element both as an actuator and a sensor. This provides the scope for significantly reducing the number of transducer elements required for complete controllability and observability of the system and hence reduce the hardware required for controlled system operation. In this paper we advocate underactuation and undersensing in dynamical systems with the objective of reducing cost, weight, and system complexity. To this end, we first illustrate the role of switching in enhancing controllability and observability in underactuated and undersensed linear time-invariant systems and determine the switching requirement for observer-based control designs. For a proof of principle, we consider the problem of vibration suppression in a flexible beam instrumented with piezoelectric transducers. Using simulation and experiments, we demonstrate feasibility of switching the piezoelectric elements between actuator and sensor modalities and establish the merit of introducing underactuation and undersensing deliberately.
LQG Control for Nonstandard Singularly Perturbed Discrete-Time Systems
Authors: Kim Beom-Soo , Kim Young-Joong , Lim Myo-Taeg
Published: March 2005

In this paper we present a control method and a high accuracy solution technique in solving the linear quadratic Gaussian problems for nonstandard singularly perturbed discrete time systems. The methodology that exists in the literature for the solution of the standard singularly perturbed discrete time linear quadratic Gaussian optimal control problem cannot be extended to the corresponding nonstandard counterpart. The solution of the linear quadratic Gaussian optimal control problem is obtained by solving the pure-slow and pure-fast reduced-order continuous-time algebraic Riccati equations and by implementing the pure-slow and pure-fast reduced-order Kalman filters. In order to show the effectiveness of the proposed method, we present the numerical result for a one-link flexible robot arm.
Delay-Independent Observer-Based Control for a Class of Neutral Systems
Authors: Kuo Jim-Ming , Lien Chang-Hua , Fan Kuo-Kung , Hsieh Jer-Guang
Published: March 2005

In this paper, the observer-based control for a class of neutral systems is considered. The analysis is based on the use of Lyapunov functional stability theory. Delay-independent stabilization criteria are proposed to guarantee stability for the systems via linear control. The linear matrix inequality (lmi) approach is used to design the observer and the feedback control. Our results are a simple generalization of a full-order Luenberger observer. A numerical example is given to illustrate the use of our main results.