bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social Science Research and Contemporary Studies of Homelessness
Authors: Shlay Anne B. , Rossi Peter H. 
Published: July 2003

This review takes stock of contemporary social science research on homelessness. Research on homelessness in the 1980s has been prompted by the increased numbers and visibility of homeless persons including men, women, and families, as well as young people without families. Most empirical research employs a working definition of homelessness as the condition of those people who are without a permanent place to live. However, a wide range in perspectives differ over what homelessness is. In part, this reflects recognition of some the dynamics of homelessness that include intermittent movement in and out of homeless situations. But it also reflects changes in social values over what constitutes adequate housing. Research shows that the population of homeless persons is diverse, although most homeless persons are young and single. Many have severe chronic problems including mental illness, alcoholism, physical disabilities, and poor health. A significant number have criminal histories. Many were raised in foster care situations. All suffer from economic deprivation, and many have experienced long-term unemployment. Considerable disagreement exists over the number of homeless persons, in part because the scarcity of resources to address this problem politicizes the debate. There is also strong disagreement over the root causes of homelessness. Debate over the causes of homelessness is caught up in whether the focus of research should be on structural forces that permit homelessness to occur or the immediate reasons why people become homeless. Research now suggests that the extreme situation of homelessness may be more accurately portrayed as the result of the convergence of many factors that drive this phenomenon, including housing market dynamics, housing and welfare policy, economic restructuring and the labor market, and personal disabilities. Policies designed to ameliorate homelessness have been inadequate to stem the tidal forces that produce such severe destitution, and this trend is likely to continue. Future important directions include addressing the role of employment and social ties in producing homelessness, comparing the economic and social situation of homeless and non-homeless persons, evaluating programs designed to aid homeless persons, and developing international comparisons of homelessness.
Media Images and the Social Construction of Reality
Authors: Gamson William A. , Croteau David , Hoynes William , Sasson Theodore 
Published: July 2003

Ideally, a media system suitable for a democracy ought to provide its readers with some coherent sense of the broader social forces that affect the conditions of their everyday lives. It is difficult to find anyone who would claim that media discourse in the United States even remotely approaches this ideal. The overwhelming conclusion is that the media generally operate in ways that promote apathy, cynicism, and quiescence, rather than active citizenship and participation. Furthermore, all the trends seem to be in the wrong direction—toward more and more messages, from fewer and bigger producers, saying less and less. That’s the bad news. The good news is that the messages provide a many-voiced, open text that can and often is read oppositionally, at least in part. Television imagery is a site of struggle where the powers that be are often forced to compete and defend what they would prefer to have taken for granted. The underdetermined nature of media discourse allows plenty of room for challengers such as social movements to offer competing constructions of reality and to find support for them from readers whose daily lives may lead them to construct meaning in ways that go beyond media imagery
The Sociology of Ethnic Conflicts: Comparative International Perspectives
Authors: Williams Robin M. 
Published: July 2003

Oppositions and deadly conflicts among ethnic collectivities are important around the word. Ethnies (our term for ethnic groups) also strongly affect interstate relations. Both interethnic and ethnic-state conflicts tend to be severe, protracted, and intractable. At the extremes, the stakes are total: survival versus genocide Competition and rivalry for individualized economic and political goods are important, but the most intense conflicts are to be expected when the stakes are collective goods, including categorical claims to prestige and political authority. States are major actors in creating, accentuating, or diminishing ethnic identities. States are both arenas of rivalry and conflict and resources for ethnic mobilization and counter-mobilization. Because both ethnies and states are diverse, careful specification is required for fruitful analysis. The same dictum applies for the diverse types of oppositions and of conflicts. Ethnic conflicts arise from complex combinations of ethnic strength, class, inequality, political opportunity, mobilization resources, interdependence, and international interventions. Frequent but nonviolent protests, for example, are most likely by organized collectivities with substantial resources, operating in relatively open political systems. International aid to parties in domestic conflicts appears to prolong and intensify ethnic struggles. Research in this field contends with many difficulties, and one-sided theories do not fare well. Yet abundant descriptive materials are available, statistical techniques are improving, conceptual clarification continues, and substantive knowledge does accumulate. Accordingly, there is hope for better understanding of some of the most destructive and tragic conflicts of our times.
Poisons in the System: The Global Regulation of Hazardous Pesticides
Authors: Hough Peter 
Published: July 2003

A number of international regimes have emerged in the last thirty years contributing to the global regulation of pesticides. These developments bear testimony to the work of pressure groups and epistemic communities in highlighting the environmentally polluting effects of hazardous pesticides, to which the regimes have contributed. However these regimes were only achievable because they also satisfied other values, given greater priority at the global level. Human health and global trade values were also at stake, rather than just the conservation of the non-human environment. This global picture is in contrast to the situation at the domestic level, where environmental values are prominent in the regulation of pesticides. It is more difficult for environmental values to be prioritized at the global level but the development of a global civil society has put environmental values on the international agenda and has led to them becoming more influential in the future development of international regimes. This article explores these arguments.
Singularity-Free Fully-Isotropic Translational Parallel Mechanisms
Authors: Carricato Marco , Parenti-Castelli Vincenzo 
Published: June 2003

Parallel mechanisms show desirable characteristics such as a large payload to robot weight ratio, considerable stiffness, low inertia and high dynamic performances. In particular, parallel manipulators with fewer than six degrees of freedom have recently attracted researchers' attention, as their employ may prove valuable in those applications in which a higher mobility is uncalled-for. The attention of this paper is focused on translational parallel mechanisms (TPMs), that is on parallel mechanisms whose output link (platform) is provided with a pure translational motion with respect to the frame. It deals with the general problem of the topological synthesis and classification of TPMs and it investigates both their constraint and direct singularities. In particular, it identifies for the first time special families of fully-isotropic mechanisms. Such manipulators exhibit outstanding properties, as they are free from singularities and show a constant orthogonal Jacobian matrix throughout their workspace. As a consequence, both the direct and the inverse position problems are linear and the kinematic analysis proves straightforward.
Regular salbutamol use increases CXCL8 responses in asthma: relationship to the eosinophil response
Authors: Gordon J.R. , Swystun V.A. , Li F. , Zhang X. , Davis B.E. , Hull P. , Cockcroft D.W. 
Published: June 2003

Regular salbutamol use can exacerbate allergen-induced airway eosinophilia in asthmatics, but its effect on airway eosinophil chemokine responses is unknown.Asthmatic subjects (n=14) were treated for 10 days with placebo or salbutamol in a double-blind, cross-over study, then given same-dose allergen challenges. Their sputa were then analysed 1 and 7 h later for a panel of eosinophil-related cytokines. Eosinophils from five test and three control subjects were tested for expression of CXCL8/interleukin (IL)‐8, and its receptors and responsiveness to CCL11/eotaxin and CXCL8/IL‐8.Sputum CXCL8/IL‐8, but not IL‐5, CCL5/regulated on activation, T‐cell expressed and secreted, CCL7/monocyte chemotactic protein‐3, CCL11/eotaxin, granulocyte-macrophage colony-stimulating factor or tumour necrosis factor levels, were increased (42%) by the salbutamol treatments. The CXCL8/IL‐8 levels correlated with the proportions of sputum eosinophils and these cells, but not other sputum cells, stained strongly for CXCL8/IL‐8. The circulating eosinophils of the tested subjects (n=5) expressed CXCL8/IL‐8 receptors and secreted high levels of this chemokine. Neutralisation of sputum CXCL8/IL‐8 reduced eosinophil chemotactic responses to these samples by 19±5%.These data suggest that regular use of salbutamol can augment airway CXCL8/interleukin‐8 responses to allergen challenge and that this CXCL8/interleukin‐8 could contribute to the airway inflammatory response.
N‐acetylcysteine reduces chemokine releaseviainhibition of p38 MAPK in human airway smooth muscle cells
Authors: Wuyts W.A. , Vanaudenaerde B.M. , Dupont L.J. , Demedts M.G. , Verleden G.M. 
Published: June 2003

Reactive oxygen species are involved in the activation of several mitogen-activated protein kinases (MAPKs), key-players in the production of several cytokines. Therefore the current study investigated whetherN‐acetylcysteine (NAC), an antioxidative agent, inhibits the interleukin (IL)‐1β‐induced expression and production of eotaxin and monocyte chemotactic protein (MCP)‐1 in human airway smooth muscle cells (HASMC).NAC (10 mM) decreased the expression of eotaxin and MCP‐1, by 46±11% (n=7) and 87±4% (n=6), respectively; the eotaxin release was inhibited by 75±5% (n=7), whereas the MCP‐1 release was decreased by 69±4% (n=10). NAC (1 mM) also decreased the IL‐1β‐induced activation of p38 MAPK.Compared with unstimulated cells, a four-fold increase in 8‐isoprostane production in IL‐1β‐stimulated HASMC was observed, which could be inhibited by NAC in a concentration-dependent way, with a maximum inhibition of 39±12% with 1 mM NAC.The present study demonstrated thatN‐acetylcysteine inhibits the interleukin‐1β‐induced eotaxin and monocyte chemotactic protein 1 expression and production due to a decreased activation of p38 mitogen-activated protein kinase. This study has also shown thatN‐acetylcysteine decreases the interleukin‐1β‐induced production of reactive oxygen species, as suggested by a reduction in the 8‐isoprostane production.
BR22, a 26 kDa thyroid transcription factor‐1 associated protein (TAP26), is expressed in human lung cells
Authors: Yang M-C.W. , Wang B. , Weissler J.C. , Margraf L.R. , Yang Y-S. 
Published: June 2003

The current authors have previously identified BR22, a thyroid transcription factor (TTF)‐1 associated protein 26 (TAP26), which interacts with TTF‐1 to enhance human surfactant protein (SP)‐B promoter activity in transfected 293 cells. However, the expression of TAP26 in the lung cells and its biological relevance to the SP‐B production under physiological conditions were not examined.In this study, endogenous co-immunoprecipitation andin situimmunohistochemical staining techniques were employed to explore the presence of TAP26 and TTF‐1 complex in the lung epithelial cells. The correlation of TAP26, TTF‐1 and SP‐B expression was inspected in H441 cells in the presence of dexamethasone, a known positive effector of the SP‐B promoter.Monoclonal antibody (mAb) against TAP26 can co-immunoprecipitate both TAP26 and TTF‐1 from H441 cells. Using this antibody inin situstaining of human lung sections, the data show that TAP26 is present in the lung alveolar epithelial cells. Reverse transcriptase-polymerase chain reaction and Western blot analyses of type-II cells as well as dexamethasone-treated H441 cells suggest that TAP26 expression is modulated coordinately with SP‐B and TTF‐1 in these cells.In summary, the current study demonstrates that thyroid transcription factor‐1 associated protein 26 is an associated protein of thyroid transcription factor‐1 in the lung alveolar epithelial cells where surfactant protein gene expressions take placein vivo.
A case‐study of an orographic cyclone south of the Alps during the MAP SOP
Authors: Buzzi A. , D'Isidoro M. , Davolio S. 
Published: June 2003

AbstractThe cyclonic formation of IOP15 of the Mesoscale Alpine Programme (MAP) (6–7 November 1999) is examined with respect to mesoscale features in the geopotential, temperature, wind and precipitation fields. The effect of orography at different scales is evaluated using a mesoscale meteorological model (BOLAM). Model errors are determined by comparing standard and special MAP SOP observations with model output. An Optimal Interpolation reanalysis of the initial condition, aimed at assimilating mesoscale structures, is applied, resulting in an overall reduction of the forecast error, including position of local scale precipitation maximum in the Lago Maggiore target area south of the Alps. Different orography representations have an impact on the error patterns, since it is shown that the Alpine orography largely controls the cyclone growth over the Mediterranean. Particular attention is devoted to the model verification of precipitation and wind fields in the vicinity of the Alps, where special observations allow for fine‐scale analysis. Copyright © 2003 Royal Meteorological Society
The mechanics of eddy transport from one hemisphere to the other
Authors: Paldor Nathan , Sigalov Andrey , Nof Doron 
Published: June 2003

AbstractThe trajectory of a dense eddy propagating along the bottom of a meridional channel of parabolic cross‐section from the southern to the northern hemisphere is described by a Hamiltonian system with two degrees of freedom. Two simplified types of motion exist in which the meridional acceleration vanishes: in midlatitudes the motion is geostrophic, poleward (equatorward) directed along the western (eastern) flank of the channel, while on the equator the motion consists of zonal oscillations along the potential‐well generated by the bottom parabolic cross‐section of the channel. The eddy's propagation along the equator is much faster than that in midlatitudes, which enhances its dissipation via mixing with the overlying ocean water. For motions that occur slightly off the equator the eastward segment is stable while the westward segment is unstable, so an expulsion from the equatorial regime takes place during the latter. A dense eddy that arrives near the equator along the west flank of the channel, has to cross the channel to its east flank where it can either oscillate back (westward) to the other side, or move poleward from the equator along the channel's east flank. The eddy's dissipation during the equatorial part of its trajectory is very large, and the probability of the dissipated eddy leaving the equator to either hemisphere is identical.The non‐integrability of the system is manifested in the sensitive combination of the equatorial and the midlatitude regimes that renders the dynamics of the transport of dense eddies across the equator chaotic. This description explains both the sharp decrease in the amount of Antarctic bottom water mass in the immediate vicinity of the equator in the western Atlantic Ocean and the ‘splitter’ effect of the equator. This effect, encountered in earlier fluid dynamical numerical simulations, causes a current, and a cloud of particles, to chaotically split into two parts flowing in different hemispheres. Copyright © 2003 Royal Meteorological Society
Factors determining the decrease in surface wind speed following the evening transition
Authors: Lapworth A. 
Published: June 2003

AbstractMeteorological measurements were made by surface instrumentation at a flat rural site over a period of several years. These are analysed to determine any systematic factors governing the decrease in surface wind speed during the evening. The 10 m wind speed is found to depend on the surface cooling and gradient wind speed, with a larger decrease in the 10 m wind speed with surface cooling when the gradient wind is stronger. The relationships are relatively unaffected by cooling rate. Momentum and heat fluxes are also found to have well defined relationships with surface cooling and gradient wind, with downward heat fluxes reaching a maximum at a 2 degC cooling. These observations are compared with the predictions of a simple semi‐analytical model which gives qualitatively similar results to the observations and shows that the greater 10 m wind speed decrease at higher gradient wind speeds is due to a thicker boundary layer. The model also predicts the formation of an upper inversion with an increase in 10 m wind later in the evening and this prediction is compared with balloon and surface observations made on a clear evening. A simple forecasting rule for the reduction in 10 m wind during the evening is given. Copyright © Crown copyright, 2003. Royal Meteorological Society
Solid‐state modification of isotactic polypropylene (iPP) via grafting of styrene. I. Polymerization experiments
Authors: Picchioni F. , Goossens J. G. P. , van Duin M. , Magusin P. 
Published: July 2003

AbstractGrafting of vinyl monomers onto isotactic polypropylene (iPP) in the solid state, that is, below the melting point, displays several advantages over melt or solution grafting processes, such as negligible degradation of the iPP and absence of any solvent. The final properties of such iPP modifications or actually compatibilized PP blends are dependent on the dispersion of the new polymer into the iPP matrix, which is controlled to a large extent by the degree of grafting versus the amount of free homopolymer formed. In the present work, the solid‐state modification of iPP by styrene has been investigated from the point of view of the monomer polymerization behavior. In order to determine the styrene conversion and the distribution of the newly formed PS phase along the radius of the iPP powder particles, the reaction products were characterized by infrared (FTIR) and Raman spectroscopy. Fractionation of the reaction products via selective solvent extraction allowed the determination of the grafting efficiency (Φ). It was shown that besides the grafted PS two additional types of PS are formed, that is, free PS homopolymer in the pores of the PP powder and free PS in the amorphous PP phase. Phi shows an optimum as a function of the feed peroxide composition and the feeding rate. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3279–3291, 2003
Crystallization and melting behaviors of maleated polyethylene and its composite with fibrous cellulose
Authors: Zhang Farao , Qiu Wulin , Yang Liqun , Endo Takashi , Hirotsu Takahiro 
Published: July 2003

AbstractThe crystallization and melting behaviors of maleated polyethylene (MPE) and its composite with fibrous crystalline cellulose are investigated by differential scanning calorimetry. MPE exhibits a higher crystallization starting temperature, because of the interactions between maleic anhydride (MA) groups for nucleation, and lower melting and crystallization enthalpies, because of the intensive irregularity of MPE chains compared to unmaleated PE (UPE). Fibrous cellulose (FC) slightly facilitates the nucleation of MPE but causes no change in the transition enthalpies of MPE for crystallization and melting in UPE–FC and MPE–FC composites. The kinetics of crystallization show that the Avrami exponent depends on the content of MA groups and FC to a small extent and the activation energy is largely determined by the MA content, suggesting the irregularity and decreased mobility of MPE chains that is due to the interactions between the grafted MA groups in MPE and the FC composite. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3292–3300, 2003
Synthesis and properties of oil absorption resins filled with polybutadiene
Authors: Shan Guo‐Rong , Xu Ping‐Ying , Weng Zhi‐Xue , Huang Zhi‐Ming 
Published: July 2003

AbstractPolybutadiene (PB) is used to fill an oil absorption resin as a physical crosslinker to construct a kind of 3‐dimensional network with a high degree crosslinking and low crosslink density. A series of acrylic resin particles with various compositions are prepared by suspension polymerization, using benzoyl peroxide (BPO) as an initiator and ethylene glycol dimethacrylate (EGDMA) as a chemical crosslinker. The effects of the polymerization temperature, initiator concentration, monomer feed ratio, and chemical and physical crosslinker concentrations on the oil absorbency and gel fraction (degree of crosslinking) are studied. The recipe and operation conditions are optimized as follows: a mass ratio of 3:1 for styrene (St)/dodecyl methacrylate or St/butyl acrylate, 0.5 wt % BPO, and 80°C for 7–8 h. The effect of the physical crosslinker (PB) concentration is complex. The oil absorbency increases with increasing PB at lower EGDMA concentrations. However, under this same condition, particles cannot be formed if the PB concentration is higher than a certain value. By contrast, there is an optimum PB concentration when the EGDMA concentration is higher. The oil absorption speed is also investigated. The presence of PB can speed up absorption. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3309–3314, 2003
Nanocomposites of poly(trimethylene terephthalate) with organoclay
Authors: Ou Cheng‐Fang 
Published: July 2003

AbstractTwo different kinds of clay were organomodified with cetylpyridinium chloride (CPC) as an intercalation agent. Poly(trimethylene terephthalate) (PTT)/organoclay nanocomposites were prepared by the solution intercalation method. Wide‐angle X‐ray diffraction (WAXD) indicated that the layers of clay were intercalated by CPC and the interlayer spacing was a function of the cationic exchange capacity (CEC) of the clay: the higher the CEC, the larger the interlayer spacing is. The WAXD studies showed that the interlayer spacing of organoclay in the nanocomposites depends on the amount of organoclay. From the results of differential scanning calorimetry analysis it was found that clay behaves as a nucleating agent and enhances the crystallization rate of PTT. The maximum enhancement of the crystallization rate for the nanocomposites was observed in nanocomposites containing about 5 wt % organoclay with a range of 1–15 wt %. The thermal stability of the nanocomposites was enhanced by the addition of 1–10 wt % organoclay as found from thermogravimetric analysis. The thermal stability of the PTT/organoclay nanocomposites was related to the organoclay content and the dispersion in the PTT matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3315–3322, 2003