bluuebunny/crossref_metadata_2025 huggingface dataset:
Trading Blocs and the Capitalist World‐Economy: Insights and Evidence
Authors: Blanton Robert G.
Published: January 2007

The structure of the world‐economy is a central issue in world‐systems research. Empirical structural analysis, however, has generally focused on a single structural aspect of the world‐system: delineation of the core, periphery, and semiperiphery. This study examines another important structural facet of the world‐system–blocs within the world trading order. The existence of blocs within the world‐economy, as well as their configuration, have implications for states at all structural positions of the world system. Analysis of blocs which exist among core states can provide insights into issues of hegemonic cycles and decline. Outside of the core, the character of clusters can provide evidence regarding peripheral mobility, fragmentation, or subimperialism. Employing two complementary network methods, asymmetric multidimensional scaling and clique detection, this study examines blocs within the world‐economy at three points since World War II: 1955, 1975, and 1994. Results indicate a somewhat multipolar, though not necessarily antagonistic, core and a somewhat fragmented periphery.
Role Acquisition as a Social Process
Authors: Yellin Linda L.
Published: January 2007

A model of the role acquisition process is proposed based on data from 310 first‐person written narratives of a single role entrance. Content analysis of data set II (N= 110) of narratives, which included forty‐seven different roles, provides support for the model. The model conceptualizes role acquisition as involving a sequence of four stages, characterized as (1) ambivalence, (2) absorption, (3) commitment, and (4) confidence, in which each stage involves a qualitatively different interaction between the person and the role: a different affective orientation on the part of the person toward the role, and a qualitatively different relationship between the person and role partners. Common features and heterogeneous effects of role type, social context, cognitive processes, and other factors at each stage are discussed.
Saving the Savior
Authors: Shahidian Hammed
Published: January 2007

This article begins with an autobiographical reflection about what sociology has meant to me as an Iranian intellectual. Sociology has enabled me to think critically about my country's politics and culture, appreciating its strengths without overlooking its unjust and injurious aspects. That experience shapes my answer to the question “Saving Sociology?” If there is anything in sociology that I would like to save–in both senses “to keep” and “to rescue”—it is sociology as a critical, reflective discipline, a discipline that not only studies society but also contributes to its change. As the contemporary world moves toward a “global” society, we are increasingly facing the dilemmas of multiculturalism. Sociologists often investigate other societies or (like myself) look back at their own from a spatial and cultural distance. This situation has created a dilemma for many scholars: Should we criticize problems stemming from “indigenous” beliefs and practices of other societies? Cultural relativism argues that different cultures provide indigenous answers to their social problems that should be judged in their own context. While this approach correctly encourages us to avoid ethnocentrism, it has led to inaction towards the suffering of oppressed groups. Reflecting on the relativist approach to sexual dominance, I question some cultural relativist assumptions. Discussing how “indigenous” responses to male domination in many cases disguise and protect that domination, I will challenge the “localist” approach of relativism and argue for a universalist approach.
The Allocation of Blacks in Large Firms and Establishments and Black‐White Wage Inequality in the U.S. Economy
Authors: Mitra Aparna
Published: January 2007

Using data from the National Longitudinal Survey of Youth (NLSY) for 1988, this study analyzes the allocation of African Americans in large firms and establishments and the effects of the allocation process on Black‐White wage inequality. The results show that Blacks are disproportionately employed in large establishments while being under‐represented in supervisory positions. The Black‐White wage differential, however, remains significant only in the large establishments, despite this study's use of detailed controls for worker quality.
Family‐Based Social Capital Considerations as Predictors of Attainments Among Appalachian Youth
Authors: Dyk Patricia Hyjer , Wilson Stephan M.
Published: January 2007

The purpose of this study was to explore social and human capital theory in application to status attainment research using a sample of 463 low‐income youth from rural Appalachian families. Comparisons were made between social capital variables based in the family of origin and social interaction variables based in the broader community as influences on the status attainment of youth. Surveys of youth were conducted during a ten‐year longitudinal study (i.e., three assessments conducted during fifth/sixth grades and eleventh/twelfth grades, and for ages twenty‐one/twenty‐two). Path analyses confirmed some of the social interaction hypotheses but demonstrated eve greater support for individual human and family social capital variables in explaining young adult attainment outcomes. Support was provided for the inclusion of family‐based social capital variables as a means of gaining a broader understanding of youth attainment.
The Effect of Male Delinquency on Mothers and Fathers: A Heuristic Study
Authors: Ambert Anne‐Marie
Published: January 2007

This paper addresses some of the lacunas extant in the empirical literature on adolescents. The focus rests on studying the impact of juvenile delinquency not on adolescents, but on their parents. From an interactional perspective, adolescents are denned as proactive social actors who contribute to the quality of their family lives. A multisample, multimethod study of delinquents’parents is conducted and finds that parents are highly affected by their children's delinquency; this effect is particularly strong for mothers compared to fathers. Difficult adolescent behaviors and delinquency lead to a series of complications and stressors in parental lives. Research questions are suggested that target a broad range of variables and themes.
The Significance of Race in the Private Sphere: Asian Americans and Spousal Preferences
Authors: Chow Sue
Published: January 2007

Using qualitative analysis of narratives of United States‐born Asians, this article examines how spousal preferences and views on interracial couples are affected by racial status inequalities. It argues that racial inequality affects those who prefer Whites, those who prefer Asians, those indicating no racial preferences, and those whose preferences changed through the life course. The dynamics of racialized preferences are explained by introducing the concept of racialized relationship capital, specifically the appeal of Euro‐American vs. ethnic‐racial relationship capital. The paper concludes by questioning the popular notion that high rates of interracial marriage indicate successful assimilation for groups such as Asian Americans.
The Structure of Russian Organizations
Authors: Miller George A. , Gubin Oleg I.
Published: January 2007

This paper examines the extent to which the structure of Russian organizations is similar to that observed among organizations in the West. Data were obtained in 1995 from a sample of organizations in the greater Moscow area by means of a structured interview schedule administered to the chief executive officer within each organization. The interview schedule contained measures developed by the Aston Group which have been used widely in previous research. The structure of Russian organizations was evaluated in terms of a causal model based upon consistent findings of previous research in this area. The results suggest that the structure of Russian organizations differs in important ways from the type of structure observed in most Western organizations. The major differences are that size, specialization and formalization are positively associated with centralization in Russian organizations. It is suggested that the historical tradition of centralized rule in Russia and the criminal environment of current Russian organizations are, in part, responsible for this difference.
Intolerance of “Others” among Palestinian and Jewish Students in Israel
Authors: Moore Dahlia
Published: January 2007

This study analyzes intolerance against diverse sociopolitical groups and compares the social and political attitudes of two distinct and highly differentiated groups: Jewish and Palestinian high‐school students in Israel. It examines their perceptions of the political context that structurates their “reality,” and aims to find the factors that influence the extremity of their intolerance. The proposed model is more applicable to Jewish students than it is to Palestinians and shows that intolerance toward out‐groups is influenced by religiosity, the salience of national and civic identity, national security issues, and political ideology.
Still Life in Black and White: Effects of Racial and Class Attitudes on Prospects for Residential Integration in Atlanta
Authors: Timberlake Jeffrey M.
Published: January 2007

I use the 1993 Atlanta Survey of Urban Inequality to evaluate the effects of five types of racial and class attitudes on assessments of the desirability of residential integration: (1) preferences for neighbors of the same race, (2) perceived racial differences in social class characteristics, (3) Whites’perceptions of group threat from Blacks, (4) Blacks’perceptions of discrimination, and (5) negative racial stereotypes. For Whites the strongest predictors of resistance to integration are negative racial stereotypes and perceptions of group threat from Blacks. For Blacks in‐group preferences, negative racial stereotypes and, to a small extent, beliefs that Whites tend to discriminate against other groups are positively associated with resistance to integration. I conclude by arguing that since racial attitudes are linked to attitudes about residential integration, open housing advocates should focus their efforts on addressing persistent racial mistrusts and prejudices.
Decomposing the Black‐White Wealth Gap: The Role of Parental Resources, Inheritance, and Investment Dynamics
Authors: Conley Dalton
Published: January 2007

Much research has shown that even after controlling for income, African Americans suffer from drastically lower net worths than their white counterparts; these differences in net worth have important implications for the overall well‐being of blacks and whites. If not directly from labor market disadvantages–i.e., income differentials–then from what does this racial gap in wealth arise? The current study assesses two complementary accounts of this race difference in asset holdings. The first, the historical legacy thesis, suggests that net wealth differences in the current generation are largely a result of discrimination in past generations; that is, they can be traced to the “head start” that whites have enjoyed in accumulating assets and passing them on. The second theory, the contemporary dynamics thesis, holds that current dynamics of institutional racism in the housing and credit markets are more responsible for the gap. The current study tests the relative impact of multi‐generational forces and contemporary property and credit dynamics by using two‐generational data from the Panel Study of Income Dynamics. It finds that parental wealth and income levels and inheritance all have a significant impact on the wealth levels of the current generation net of respondent socioeconomic characteristics; however, parental wealth and inheritance fail to explain the black‐white gap. Further, this study shows that even predicting net worth from that same family's net worth five years prior (also controlling for savings during the interim), there remains a significantly negative effect of African American race. However, breaking out initial net worth into asset types shows that it may be different investment types and returns that explain the difference in asset accumulation over a five‐year period.
Fear of the “Alien Other”: Cultural Anxiety and Opinions about Japan
Authors: Neuman W. Lawrence
Published: January 2007

American public opinion toward Japan grew more negative coincident with 1980s “Japan‐bashing” media messages. Two theories of opinion formation provide explanations for this. Democratic representation theory understands opinions as rational responses to new information. Cultural interpretation theory holds that public opinion is based on one's receptiveness to media discourse. Opinion is neither a rational response to information nor the passive acceptance of elite dictates. People differentially interpret media messages and form opinions in a process that is shaped by media attentiveness and their subjective cultural anxieties. Survey data permit an indirect test of the two theories applied to anti‐Japan opinion. OLS regression analysis performed on GSS for four time periods reveals that anti‐Japan opinion is rooted less in “rational” responses to personal economic insecurity or fear of increased global competition than in racial attitudes and domestic social‐cultural concerns. America's negative opinion toward Japan in the 1990s is better understood as domestic anxieties that are redirected toward a symbolic target that the mass media has highlighted.
“Did You See What I Saw?” Gender Differences in Perceptions of Avenues to Prestige among Adolescents
Authors: Suitor J. Jill , Minyard Staci A. , Carter Rebecca S.
Published: January 2007

We use data from 1,796 college students to explore gender differences in perceptions of avenues to prestige during adolescence. Students attending seven large universities during the 1997–98 academic year provided information on the ways in which adolescents in their high schools had gained prestige with peers. The analysis reveals substantial gender differences in perceptions regarding the most common avenues to prestige. Most important, men were less likely than women to report that female students in their high schools accrued prestige through sports and grades, and more likely than women to report that male students accrued prestige through engaging in deviant behaviors, such as sexual activity, drug and alcohol use, and fighting. We discuss the findings in the context of gender differences in social perception and gender‐role attitudes.
The Premise and Promise of Citizenship and Civil Society for Renewing Democracies and Empowering Sustainable Communities
Authors: Aigner Stephen M. , Flora Cornelia B. , Hernandez Juan M.
Published: January 2007

State regimes have launched policies to “reinvent” government and “regenerate” communities in peripheral impoverished rural and urban areas to build sustainable communities and reduce poverty. We investigate the impact of policy concepts–the empowerment paradigm, citizenship as citizen participation and inclusion, and associations between the state and civil society–on local areas' success in leveraging dollars to foster sustainable economic and community development in persistently poor rural areas of the U.S. The thirty‐three rural sites of the Empowerment Zone/Enterprise Communities Initiative of the Clinton‐Gore Administration comprise our database. We find that empowering area‐based, low‐income residents through the election mechanism to choose their representatives on the local sites' governing board is strongly and significantly related to both inclusion and citizen participation. Also, the presence of elected citizens with connections to civil society on the governing body contributes strongly to later success in leveraging dollars.
Do State‐Designated Enterprise Zones Promote Economic Growth?
Authors: Beck Frank D.
Published: January 2007

In light of the economic stresses faced by many urban and rural places in the 1970s and 1980s, many communities began actively promoting local economic growth. Subsequently, sociologists became interested in the effectiveness of such efforts. In particular, they wanted to know whether places can purposefully alter their economies, or whether ecological and other factors commonly associated with growth are more powerful. State‐designated enterprise zones are an example of such attempts. Data were collected from 51 enterprise zones in the United States. The data indicate that growth in number of firms and number of jobs within the zones did occur. The data also indicate that the rate of growth in the zone often surpassed its respective county. Further, while tax incentives are often touted as the key to economic development, this research finds that attention to the services and quality of life in the zone and a wide range of incentives overall matter more than the provision of tax cuts, subsidies, and other financial incentives alone. These results hold after controlling for other factors known to affect economic development.
Effects of Wind on the Allometry of Two Species of Plants in an Elfin Cloud Forest
Authors: Cordero Roberto A. , Fetcher Ned , Voltzow Janice
Published: January 2007

Thigmomorphogenesis includes the effects of mechanical perturbation on plant growth. To test whether thigmomorphogenesis is evident at different scales within plants, we investigated the effect of wind on allometric relationships between specific plant parts. We chose two species from the elfin cloud forest of Puerto Rico that have contrasting growth habits, the shrub Clibadiun erosum (Asteraceae) and the palm Prestoea acuminata var. montana (Arecaceae), and subjected them to barrier‐protected and wind‐exposed treatments. For C. erosum, we compared the allometry of stems and branches against three allometric models that predict that plant height or branch length increases at the 1, 2/3, and 1/2 power of stem diameter. Only the geometric similarity model (scaling exponent of 1) seemed to hold when plants were exposed to the wind. We found relatively fewer leaves per number of branches produced and fewer leaves per increment of branch diameter in the plants of C. erosum exposed to the wind. Mean petiole length ratios (petiole length/basal radius) of P. acuminata were higher on leaves of barrier‐protected plants for both simple and compound leaves, indicating that petioles were stouter and mechanically safer in the wind‐exposed plants. We suggest that alteration of the allometric relationships of plant parts, organs, or plant modules (stems and branches of C. erosum and leaves of P. acuminata) and alteration of the number of plant parts (leaves and branches of C. erosum) are adaptive responses resulting from the mechanical perturbation induced by wind in the elfin forest.
The Contextual Effect of School Attachment on Young Adolescents’ Alcohol Use
Authors: Henry Kimberly L. , Slater Michael D.
Published: January 2007

Background:  The school is a primary context for social interaction, cultivation of interpersonal skills, formation of peer groups, self‐expression, and development of self. Several studies have demonstrated that the social context of the school has important implications for determining the likelihood that an adolescent will follow a prosocial path through adolescence as opposed to becoming involved in delinquent behavior.

Methods:  Using a data set of 4,216 youth in 32 middle schools and junior high schools across the United States, this paper examines the effect of a student’s own level of school attachment as well as the contextual level of school attachment (the normative level of school attachment in a school) on 5 alcohol‐related measures: recent use of alcohol, intention to use alcohol, normative beliefs about peer use of alcohol, attitudes toward alcohol use, and aspirations consistent with alcohol use.

Results:  This study demonstrates that regardless of a student’s own level of school attachment, students who attend schools where the pupils overall tend to be well attached to school are less likely to use alcohol. In addition, they also have lower intentions to use alcohol, perceive that fewer of their peers at school use alcohol, and more strongly hold aspirations that are inconsistent with alcohol use.

Conclusions:  Our findings, along with the findings of related studies, provide support for the hypothesis that improvement of school climate may result in less substance use among students.
Surveying Students About Controversial Subjects
Authors: Soronen Lisa E.
Published: January 2007

Background:  Because of school districts’ interest in best serving the health needs of students, many choose to administer surveys addressing controversial topics. Administering such surveys in a voluntary and anonymous manner may help reduce conflict.

Methods:  This is a review of 2 recent federal court of appeals decisions regarding surveying students about controversial topics.

Results:  The 2 federal appellate cases examined whether mistakes and misperceptions were made when surveying students about controversial topics violated the US Constitution. Both courts wrestled with the tension between school and parental authority but ultimately ruled in favor of the defendant school district. In Fields v Palmdale School District, the Ninth Circuit stated that a parent’s right to control a child’s upbringing does not automatically supersede the school’s authority to control what goes on during school, including surveying students. In C.N. v Ridgewood Board of Education, the Third Circuit decided that a parent’s right to control a child’s upbringing extends into school, but surveying students about controversial topics does not violate that right. This article explains the significance of these cases and provides 10 suggestions school districts can follow to avoid the threat of litigation when surveying students about controversial topics.

Conclusions:  School districts should ensure a student survey relates to the district’s overall educational goals. Likewise, the district should adequately inform parents of a survey’s contents, date of administration, and a parent’s ability to opt out. Schools should make sure a survey is truly voluntary and anonymous. Finally, schools should carefully follow local policy and state and federal laws that apply to surveying students, such as the federal Protection of Pupil Rights Amendment.
China's Changing Economic Structure and Implications for Regional Patterns of Trade, Production and Integration
Authors: Tan Kim Song , Khor Hoe Ee
Published: January 2007

Without intending to do so, China has in recent years played a major role in East Asia's economic integration. It has done so mainly through the production and supply chain networks it has spun across the region. This paper argues that given the developmental trends in the Chinese economy, the Chinese government should pursue a more active strategy towards a broader and more balanced economic integration with the region. The emergence of a multi‐track production structure, increased importance of domestic consumption and the services sector, together with faster integration of the domestic economy, will fundamentally change China's trade and investment relationships with the rest of East Asia and necessitate a review of China's economic integration strategy. The paper also argues that ASEAN can play a useful role in facilitating the region‐wide integration process.

(Edited by Xiaoming Feng)
Anthropocene Geopolitics: Globalisation, Empire, Environment and Critique
Authors: Dalby Simon
Published: January 2007

Critique is about challenging the taken for granted categories in scholarly and political discourse. Three aspects of contemporary politics at the biggest of scales are subject to critique here: the assumptions underlying the War on Terror, globalisation and the notion of environment. The global War on Terror is not really global, and might well be better understood by using imperial analogies from the past. Globalisation, once its implicit geographies are directly addressed, might be better understood as a matter of glurbanisation. Likewise earth system science, and its suggestion that human actions are now on such a large scale that we live in a new geological period, the Anthropocene, requires us to rethink assumptions of our living within an external environment. Taken together these criticisms of the taken for granted spatial categories of contemporary political life raise big questions for how geography is now understood and how we might teach it in the future. Such an analysis also suggests the continued importance of critique as an intellectual practice in the academy.
On a Novel Annular Sector Cascade Technique
Authors: Povey T. , Jones T. V. , Oldfield M. L. G.
Published: January 2007

An advanced technique for establishing pressure boundary conditions in annular sector cascade experiments has been developed. This novel technique represents an improvement over previous methods and provides the first means by which annular sector boundary conditions that are representative of those which develop in an annular cascade can be established with a high degree of satisfaction. The technique will enable cascade designers to exploit the obvious advantages of annular sector cascade testing: the reduced cost of both facility manufacture and facility operation and the use of engine parts in place of two-dimensional counterparts. By employing an annular sector of deswirl vanes downstream of the annular sector of test vanes, the radial pressure gradient established in the swirling flow downstream of the test vanes is not disturbed. The deswirl vane exit flow—which has zero swirl velocity—can be exhausted without unsteadiness, and without the risk of separation, into a plenum at constant pressure. The pressure ratio across the annular sector of test vanes can be tuned by adjusting the throat area at the deswirl vane exit plane. Flow conditioning systems which utilize the Oxford deswirl vane technology have previously been used to set pressure boundary conditions downstream of fully annular cascades in both model and engine scale (the Isentropic Light Piston Facility at Farnborough) experimental research facilities (Povey, T., Chana, K. S., Oldfield, M. L. G., Jones, T. V., and Owen, A. K., 2001, Proceedings of the ImechE Advances in Fluid Machinery Design Seminar, London, June 13; Povey, T., Chana, K. S., Jones, T. V., and Oldfield, M. L. G., 2003, Advances of CFD in Fluid Machinery Design, ImechE Professional Engineering, London, pp. 65–94). The deswirl vane is particularly suited to the control of highly whirling transonic flows. It has been demonstrated by direct comparison of aerodynamic measurements from fully annular and annular sector experiments that the use of a deswirl vane sector for flow conditioning at the exit of an annular sector cascade represents an attractive novel solution to the boundary condition problem. The annular sector technique is now described.
Aerodynamic Design and Testing of Three Low Solidity Steam Turbine Nozzle Cascades
Authors: Song Bo , Ng Wing F. , Cotroneo Joseph A. , Hofer Douglas C. , Siden Gunnar
Published: January 2007

Three sets of low solidity steam turbine nozzle cascades were designed and tested. The objective was to reduce cost through a reduction in parts count while maintaining or improving performance. The primary application is for steam turbine high pressure sections where Mach numbers are subsonic and high levels of unguided turning can be tolerated. The base line design A has a ratio of pitch to axial chord of 1.2. This is the pitch diameter section of a 50% reaction stage that has been verified by multistage testing on steam to have a high level of efficiency. Designs B and C have ratios of pitch to axial chord of 1.5 and 1.8, respectively. All three designs satisfy the same inlet and exit vector diagrams. Analytical surface Mach number distributions and boundary layer transition predictions are presented. Extensive cascade test measurements were carried out for a broad incidence range from −60to+35deg. At each incidence, four outlet Mach numbers were tested, ranging from 0.2 to 0.8, with the corresponding Reynolds number variation from 1.8×105 to 9.0×105. Experimental results of loss coefficient and blade surface Mach number are presented and compared for the three cascades. The experimental results have demonstrated low losses over the tested Mach number range for a wide range of incidence from −45to15deg. Designs B and C have lower profile losses than design A. The associated flow physics is interpreted using the results of wake profile, blade surface Mach number distribution, and blade surface oil flow visualization, with the emphasis placed on the loss mechanisms for different flow conditions and the loss reduction mechanism with lower solidity. The effect of the higher profile loading of the lower solidity designs on increased end wall losses induced by increased secondary flow, especially on low aspect ratio designs, is the subject of ongoing studies.
Preliminary Fan Design for a Silent Aircraft
Authors: Crichton Daniel , Xu Liping , Hall Cesare A.
Published: January 2007

Preliminary fan design for a functionally silent aircraft has been performed with noise reduction as the primary goal. For such an aircraft the fan design must, in addition to delivering low cruise fuel burn, enable low jet and fan source noise during takeoff. This requires the fan to be operating at low pressure ratio and high efficiency during takeoff and, for conditions where the relative tip Mach number onto the fan is supersonic, ensuring the primary shock structure is ingested into the blade passage. To meet these requirements, flyover and cruise flow coefficients are matched using a variable area nozzle at the same time as delivering low takeoff FPR. This places the sideline operating point near the shoulder of the characteristic and fixes the top of climb and cruise fan pressure ratios. For a 4-engine, 250pax, 4000nm silent aircraft this approach leads to a top of climb FPR of 1.45, requiring a 39% increase in nozzle area at takeoff. A fan rotor has been designed for this cycle with 20 blades, low tip loading during takeoff, and a 350m∕s top of climb tip speed.
Solar Photocatalytic Detoxification and Disinfection of Water: Recent Overview
Authors: Blanco-Galvez Julián , Fernández-Ibáñez Pilar , Malato-Rodríguez Sixto
Published: January 2007

During the last few years, there has been a plethora of research and development in the area of solar photocatalysis (TiO2 and photo-Fenton). This overview, of the most recent papers on the use of sunlight to produce the O∙H, comments on those most relevant to the development of the technology and summarizes most of the recent research related to the degradation of water contaminants, and how solar photocatalysis (coupled with biotreatment) could significantly contribute to the treatment of very persistent toxic compounds. Various solar reactors for photocatalytic water treatment based mainly on nonconcentrating collectors developed during the last few years are also described in detail. This review also reports the use of the photocatalytic processes (TiO2) to inactivate microorganisms present in water, placing special emphasis on those applications that make use of sunlight. Work on water disinfection mechanisms in the last decade is summarized in the last part of this overview, with attention to some experimental systems developed to optimize this disinfection technology.
New CPC Solar Collector for Planar Absorbers Immersed in Dielectrics. Application to the Treatment of Contaminated Water
Authors: Chaves Julio , Pereira Manuel Collares
Published: January 2007

The most energetic part of the solar radiation spectrum can be used in the presence of a catalyst (Photo Catalysis) or in Photo Fenton techniques to treat chemically or biologically contaminated water. This process requires an efficient optics to collect and deliver solar radiation to the liquid to be treated. Non Imaging Optics provides the most efficient way to collect solar radiation and in the present paper we describe one optical solution for absorbing surfaces holding the catalyst and immersed in the water to be treated. The water circulates in UV and blue transparent glass tubes and the absorber is a flat fin parallel to the optical axis of the system. An optical solution is derived, achieving maximum concentration without rays being geometrically rejected. However, it is shown that this concentration falls short by a small margin of the maximum concentration predicted by ideality in Non Imaging Optics because of caustic formation inside the dielectric. In the paper we present an example developed for the investigation of photocatalysis in the treatment of biologically contaminated waters.
Diminished Ciprofloxacin-Induced Chondrotoxicity by Supplementation with Magnesium and Vitamin E in Immature Rats
Authors: Pfister Kerstin , Mazur Dago , Vormann Jürgen , Stahlmann Ralf
Published: January 2007

Quinolone-induced chondrotoxicity in juvenile rats and multiple other species has been demonstrated previously. Identical damages can be induced in immature rats by feeding them a magnesium-deficient diet. The objective of the present study was to investigate whether, in reverse, oral supplementation with magnesium, vitamin E, or both can diminish the typical quinolone-induced arthropathy in juvenile Wistar rats. Four groups of 12 (6 male, 6 female) 24-day-old Wistar rats were each fed either normal feed (group A), a vitamin E-enriched diet (group B), a magnesium-enriched diet (group C), or a diet enriched with both vitamin E and magnesium (group D) for 10 days. All rats received two subcutaneous ciprofloxacin doses of 600 mg/kg of body weight on postnatal day 32. Two days later, the rats were sacrificed and cartilage samples from knee joints were examined under a light microscope for the presence of typical quinolone-induced joint cartilage lesions. In addition, magnesium, calcium, and vitamin E concentrations in cartilage and plasma were determined. In the samples from rats fed a normal diet (group A), 17 quinolone-induced joint cartilage lesions were observed. In groups fed an enriched diet, the incidence of specific lesions (
n
) was significantly lower: group B,
n
= 10 (41% reduction compared to the incidence for group A;
P
< 0.05); group C,
n
= 6 (65% reduction;
P
< 0.01); and group D,
n
= 3 (82% reduction;
P
< 0.01). In comparison to the standard diet, diets with magnesium and vitamin E supplementation resulted in significantly higher magnesium and vitamin E concentrations in plasma and articular cartilage. Supplementation with magnesium and vitamin E alone or in combination may relevantly diminish joint cartilage lesions induced by quinolones in immature rats, with an additive effect of combined supplementation. The data further support the proposed pathomechanism of quinolone-induced arthropathy and the crucial role of magnesium in immature joint cartilage.
Independent Evolution of Pyrimethamine Resistance in
Plasmodium falciparum
Isolates in Melanesia
Authors: Mita Toshihiro , Tanabe Kazuyuki , Takahashi Nobuyuki , Tsukahara Takahiro , Eto Hideaki , Dysoley Lek , Ohmae Hiroshi , Kita Kiyoshi , Krudsood Srivicha , Looareesuwan Sornchai , Kaneko Akira , Björkman Anders , Kobayakawa Takatoshi
Published: January 2007

Pyrimethamine resistance in
Plasmodium falciparum
has previously been shown to have emerged once in Southeast Asia, from where it spread to Africa. Pyrimethamine resistance in this parasite is known to be conferred by mutations in the gene encoding dihydrofolate reductase (
dhfr
). We have analyzed polymorphisms in
dhfr
as well as microsatellite haplotypes flanking this gene in a total of 285 isolates from different regions of Melanesia (Papua New Guinea, Vanuatu, and the Solomon Islands) and Southeast Asia (Thailand and Cambodia). Nearly all isolates (92%) in Melanesia were shown to carry a
dhfr
double mutation (CN

RN

I [underlining indicates the mutation]) at positions 50, 51, 59, 108, and 164, whereas 98% of Southeast Asian isolates were either triple (C

IRN

I) or quadruple (C

IRNL

) mutants. Microsatellite analysis revealed two distinct lineages of
dhfr
double mutants in Melanesia. One lineage had the same microsatellite haplotype as that previously reported for Southeast Asia and Africa, suggesting the spread of this allele to Melanesia from Southeast Asia. The other lineage had a unique, previously undescribed microsatellite haplotype, indicative of the de novo emergence of pyrimethamine resistance in Melanesia.
Antimicrobial Activities of Ceragenins against Clinical Isolates of Resistant
Staphylococcus aureus
Authors: Chin Judy N. , Rybak Michael J. , Cheung Chrissy M. , Savage Paul B.
Published: January 2007

The rise in the rates of glycopeptide resistance among
Staphylococcus aureus
isolates is concerning and underscores the need for the development of novel potent compounds. Ceragenins CSA-8 and CSA-13, cationic steroid molecules that mimic endogenous antimicrobial peptides, have previously been demonstrated to possess broad-spectrum activities against multidrug-resistant bacteria. We examined the activities of CSA-8 and CSA-13 against clinical isolates of vancomycin-intermediate
S. aureus
(VISA), heterogeneous vancomycin-intermediate
S. aureus
(hVISA), as well as vancomycin-resistant
S. aureus
(VRSA) and compared them to those of daptomycin, linezolid, and vancomycin by susceptibility testing and killing curve analysis. We also examined CSA-13 for its concentration-dependent activity, inoculum effect, postantibiotic effect (PAE), and synergy in combination with various antimicrobials. Overall, the MICs and minimal bactericidal concentrations of CSA-13 were fourfold lower than those of CSA-8. Time-kill curve analysis of the VRSA, VISA, and hVISA clinical isolates demonstrated concentration-dependent bactericidal killing. An inoculum effect was also observed when a higher starting bacterial density was used, with the time required to achieve 99.9% killing reaching 1 h with a 6-log
10
-CFU/ml starting inoculum, whereas it was ≥24 h with a 8- to 9-log
10
-CFU/ml starting inoculum with 10× the MIC (
P
≤ 0.001). A concentration-dependent PAE was demonstrated with CSA-13, nearly doubling from 2× to 4× the MIC (
P
= 0.03). With respect to the CSA-13 antimicrobial combinations, time-kill curve analysis showed no difference in the log
10
CFU/ml at 24 h for the majority of the organisms tested. However, early synergy at 4 to 8 h was detected against the VRSA Pennsylvania strain (2002) when CSA-13 was tested in combination with gentamicin, while early additivity was demonstrated against all of the other organisms.
α-Tubulin Minichromosome Promoters in the Stichotrichous Ciliate
Stylonychia lemnae
Authors: Skovorodkin Ilya , Pimenov Alexander , Raykhel Irina , Schimanski Bernd , Ammermann Dieter , Günzl Arthur
Published: January 2007

Ciliated protists are model organisms for a number of molecular phenomena including telomerase function, self-splicing introns, and an RNA interference-related mechanism in programmed DNA elimination. Despite this relevance, our knowledge about promoters and transcriptional regulation in these organisms is very limited. The macronuclear genome of stichotrichous ciliates consists of minichromosomes which typically encode a single gene. The 5′ nontranscribed spacers are usually no longer than 400 bp and highly suitable for promoter characterizations. We used microinjection of two artificial and differently tagged α1 tubulin minichromosomes into the macronucleus of
Stylonychia lemnae
as a means to characterize in detail the corresponding promoter. Clonal cell lines that stably maintained both minichromosomes were generated, enabling comparative expression analysis by primer extension assays. Deletion and block substitution mutations of one of the minichromosomes revealed a TATA-like element, a putative initiator element, and two distinct upstream sequence elements (USEs). Determination of transcription initiation sites and a sequence alignment indicated that both TATA-like and initiator elements are conserved components of
S. lemnae
minichromosomes, whereas the USEs appear to be specific for the α1 tubulin minichromosome. The α2 tubulin minichromosome promoter is very short, comprising the two proximal elements but not the USEs. Despite the latter finding, up-regulation of α-tubulin expression in cells treated with concanavalin A activated the α2 but not the α1 tubulin promoter. These results therefore show that gene expression regulation in
S. lemnae
occurs at the level of transcription initiation on the basis of structurally different promoters.
Rat Model of Polymicrobial Infection, Immunity, and Alveolar Bone Resorption in Periodontal Disease
Authors: Kesavalu Lakshmyya , Sathishkumar Sabapathi , Bakthavatchalu Vasudevan , Matthews Chad , Dawson Dolph , Steffen Michelle , Ebersole Jeffrey L.
Published: January 2007

One of the predominant polymicrobial infections of humans is expressed clinically as periodontal disease.
Porphyromonas gingivalis
,
Treponema denticola
, and
Tannerella forsythia
have been strongly implicated as members of a pathogenic consortium in the etiology of adult periodontitis. In this study we hypothesized that
P. gingivalis
,
T. denticola
, and
T. forsythia
are synergistic in terms of virulence potential and induce chronic periodontal inflammation that leads to alveolar bone resorption in a polymicrobial infection in rats. Groups of rats were infected with either
P. gingivalis
,
T. denticola
, or
T. forsythia
in monomicrobial infections or with all three species in polymicrobial oral infections with or without
Fusobacterium nucleatum
. PCR analyses of oral microbial samples demonstrated that rats infected with one bacterium were orally colonized by each of the bacteria during the study interval, and increased serum immunoglobulin G (IgG) antibody levels substantiated the interaction of the host with the infecting bacteria. PCR analyses of the rats with polymicrobial infections demonstrated that most rats were infected with
P. gingivalis
,
T. denticola
, and
T. forsythia
as a consortium. Furthermore, all rats exhibited a significant increase in the level of IgG antibody to the polymicrobial consortium. Radiographic measurement of alveolar bone resorption showed that rats infected with the polymicrobial consortium with or without
F. nucleatum
exhibited significantly increased alveolar bone resorption compared to the resorption in uninfected control rats, as well as the resorption in rats infected with one of the microbes. These results documented that
P. gingivalis
,
T. denticola
, and
T. forsythia
not only exist as a consortium that is associated with chronic periodontitis but also exhibit synergistic virulence resulting in the immunoinflammatory bone resorption characteristic of periodontitis.
Interleukin-12 Promotes Gamma Interferon-Dependent Neutrophil Recruitment in the Lung and Improves Protection against Respiratory
Streptococcus pneumoniae
Infection
Authors: Sun Keer , Salmon Sharon L. , Lotz Steven A. , Metzger Dennis W.
Published: January 2007

The ability of exogenous interleukin-12 (IL-12) to elicit protective innate immune responses against the extracellular pathogen
Streptococcus pneumoniae
was tested by infecting BALB/c mice intranasally (i.n.) with
S. pneumoniae
after i.n. administration of IL-12. It was found that administration of IL-12 resulted in lower bacterial burdens in the infected mice and significantly improved survival rates. All IL-12-treated mice contained higher levels of pulmonary gamma interferon (IFN-γ) after infection and significantly more neutrophils than infected mice not treated with IL-12. IFN-γ was found to be essential for IL-12-induced resistance and for neutrophil influx into the lungs, and the observed changes correlated with increased levels of the IL-8 homologue keratinocyte-derived chemokine (KC). In addition, in vitro tumor necrosis factor alpha (TNF-α) production by alveolar macrophages stimulated with heat-killed pneumococci was enhanced by IFN-γ, and TNF-α in turn could enhance production of KC by lung cells. Finally, IL-12-induced protection was dependent upon the presence of neutrophils and the KC receptor CXCR2. Taken together, the results indicate that exogenous IL-12 can improve innate defense in the lung against
S. pneumoniae
by inducing IFN-γ production, which in turn enhances chemokine expression, and promotes pulmonary neutrophil recruitment into the infected lung. The findings show that IL-12 and IFN-γ can mediate a protective effect against respiratory infection caused by extracellular bacterial pathogens.
Resistance ofFrancisella tularensisStrains against Reactive Nitrogen and Oxygen Species with Special Reference to the Role of KatG
Authors: Lindgren Helena , Shen Hua , Zingmark Carl , Golovliov Igor , Conlan Wayne , Sjöstedt Anders
Published: January 2007

Francisella tularensisis a facultative intracellular bacterial pathogen capable of proliferating within host macrophages. The mechanisms that explain the differences in virulence between various strains of the species are not well characterized. In the present study, we show that both attenuated (strain LVS) and virulent (strains FSC200 and SCHU S4) strains of the pathogen replicate at similar rates in resting murine peritoneal exudate cells (PEC). However, when PEC were activated by exposure to gamma interferon (IFN-γ), they killed LVS more rapidly than virulent strains of the pathogen. Addition ofNG-monomethyl-l-arginine, an inhibitor of inducible nitric oxide synthase, to IFN-γ-treated PEC, completely inhibited killing of the virulent strains, whereas it only partially blocked the killing of LVS. Similarly, in a cell-free system, SCHU S4 and FSC200 were more resistant to killing by H2O2and ONOO−thanF. tularensisLVS. Catalase encoded bykatGis a bacterial factor that can detoxify bactericidal compounds such as H2O2and ONOO−. To investigate its contribution to the virulence ofF. tularensis,katGdeletion-containing mutants of SCHU S4 and LVS were generated. Both mutants demonstrated enhanced susceptibility to H2O2in vitro but replicated as effectively as the parental strains in unstimulated PEC. In mice, LVS-ΔkatGwas significantly attenuated compared to LVS whereas SCHU S4-ΔkatG, despite slower replication, killed mice as quickly as SCHU S4. This implies that clinical strains of the pathogen havekatG-independent mechanisms to combat the antimicrobial effects exerted by H2O2and ONOO−, the loss of which could have contributed to the attenuation of LVS.
Aortic stenosis in cardiovascular ochronosis
Authors: Ffolkes L V , Brull D , Krywawych S , Hayward M , Hughes S E
Published: January 2007

Alkaptonuria (endogenous ochronosis) is a rare metabolic disorder caused by a deficiency of homogentisic acid oxidase, an enzyme responsible for the metabolic degradation of tyrosine. Patients with alkaptonuria commonly present with joint pain owing to degenerative arthritis. Other affected patients may present with pigmentation of the ear cartilage and sclera. This article reports a case of aortic stenosis associated with ochronosis in a 48-year-old man who presented with severe cardiac failure. He had no previous diagnosis of alkaptonuria, which was confirmed by mass spectrometry analysis of urine. The pathogenesis of cardiovascular ochronosis is unclear, but is probably related to the extensive extracellular deposits of ochronotic pigment in the cardiac tissue.