bluuebunny/crossref_metadata_2025 huggingface dataset:
Implications of Timing of Entering Adulthood for Identity Achievement
Authors: Fadjukoff Päivi , Kokko Katja , Pulkkinen Lea
Published: August 2007

Five external markers of adulthood, self-perceived adulthood at age 27, and identity achievement at ages 27, 36, and 42 were explored for 95 women and 94 men in a cohort of Finns born in 1959. Earlier transition to adulthood in family life (moving from the parental home, entering marriage or cohabitation, having a child) anticipated higher identity achievement in adulthood. However, later transition to adulthood in working life, composed of the first certification conferral, and entering a full-time job were associated with higher identity achievement. Both components correlated with the higher level and thus the length of education. Self-perceived adulthood was unrelated to the age of achieving external markers of adulthood but was positively associated with identity achievement in women.
Emerging Adulthood in Mexican and Spanish Youth
Authors: Fierro Arias Daniel , Moreno Hernández Amparo
Published: August 2007

A delay in the end of the adolescent period, and hence the onset of common adult roles, is a trend in most of today's Western industrialized societies. Related to this fact, in recent years emerging adulthood has been proposed as a distinct developmental period between adolescence and young adulthood. Typical normative markers of adulthood are seemingly being replaced by more personal ones, defining the transition in more individualistic terms. This study applied an adaptation of the Inventory of Dimensions of Emerging Adulthood (Reifman, Arnett, & Colwell, 2006) to 720 Mexican and Spanish males and females aged 16 to 34, whose educational level ranged from high school to postgraduate work, to investigate their agreement with descriptions of the stated period as regarding their own lives. Factor analysis revealed seven subscales related to transition to adulthood. Developmental and national differences are also linked to Mexican and Spanish realities. These youths' representations of adolescence and adulthood support to some extent the concept of a new period between these stages. Findings are discussed in terms of cultural and theoretical implications.
Emerging Adulthood in Europe
Authors: Buhl Heike M. , Lanz Margherita
Published: August 2007

The fact that there is a specific age marking the emergence of adulthood in the United States has been well documented. The starting point for the studies included in this special issue is the assumption that the same can be said for European countries. Thus, a comparison of characteristics of emerging adulthood between different European countries was performed. In this special issue, contributions of scholars from five different European countries are taken as representative of different regions: Spain, Italy, Finland, Germany, and the Czech Republic. The efforts of the research are twofold. The first is to look at how the traditional markers of adulthood have changed and how the concept of adulthood is seen in the different countries. The second is to highlight the influence that the entrance into the working world and romantic partnership have on emerging adults and to detect the impact of the timing of entering adulthood on identity achievement. The results are presented here as different pathways that emerging adults follow to reach the same goal of mature adulthood.
Do I Really Need Someone in Order to Become an Adult? Romantic Relationships During Emerging Adulthood in Italy
Authors: Lanz Margherita , Tagliabue Semira
Published: August 2007

Italian emerging adults stay at home with their parents until they marry. Being involved in a romantic relationship may be considered one precursor of the success of the transition to adulthood. In this study, 92 dating and 84 nondating emerging adults were compared on when they left the parental home and their future plans. They were also compared on individual outcomes (depression, sense of coherence, and self-esteem) and their perception of parental emotional support. Finally, the influence of parental and romantic relationships on individual outcomes was investigated. Results show that dating emerging adults do not differ from nondating emerging adults about perception of emotional support from parents and about most of the outcomes. However, there are differences in time leaving the parental home, future plans, and the influence of relationships on outcomes. In conclusion, different paths characterize emerging adulthood, confirming the heterogeneity of this period also in the Italian context.
Assessment of prenatal tobacco smoke exposure by determining nicotine and its metabolites in meconium
Authors: Köhler E. , Avenarius S. , Rabsilber A. , Gerloff C. , Jorch G.
Published: August 2007

Meconium samples collected from 115 neonates were analysed for nicotine, cotinine and trans -3-hydroxycotinine (OH-cotinine) by means of high-performance liquid chromatography (HPLC) to identify prenatal smoke exposure. The self-reported maternal smoking status during pregnancy was determined by means of a questionnaire and verified by measurements in urine prior to childbirth. The total sum of nicotine and its metabolites (Sumtot) of the first passed meconium samples was 1560 ± 1024 pmol/g in newborns of smoking mothers. Smoking of less than five cigarettes was clearly detected. Sumtot remained constant in all meconium samples passed by a neonate in succession. However, the proportion of nicotine decreased with the time of passage after birth and the OH-cotinine proportion increased, whereas cotinine hardly changed. Nicotine or its metabolites were not detectable in meconium (detection limit < 20 pmol/g), when the mothers were only exposed to environmental tobacco smoke (ETS) using the HPLC method. The hypothesis that the content of nicotine metabolites in meconium reflects long-term smoke exposure could not be confirmed in newborns whose mothers had quit smoking during the latter half of pregnancy. Determining Sumtot enables the intensity of continuous smoking during pregnancy to be estimated in all meconium samples passed by a newborn. Human & Experimental Toxicology (2007) 26: 535—544
Hyperamylasemia and acute pancreatitis following anticholinesterase poisoning
Authors: Singh Surjit , Bhardwaj Udaybhan , Verma Suresh k. , Bhalla Ashish , Gill Kirandip
Published: August 2007

A prospective study was undertaken to find the incidence of hyperamylasemia and acute pancreatitis in patients with anticholinesterase poisoning. This was done by serial estimation of total serum amylase and pancreatic imaging by ultrasonography and confirmed, if necessary, by computerized tomography. Anticholinesterase poisoning was caused by either ingestion or accidental exposure to organophosphates or carbamates; it was diagnosed when patients presented with features of cholinergic crisis, depressed serum butrylcholinesterase activity of >50% and showed improvement following administration of atropine alone or atropine and 2-PAM. All the patients admitted with anticholinesterase poisoning between July 2001 and June 2005 were prospectively studied for elevated serum amylase. The serum amylase levels were estimated daily up to 10 days in survivors and in nonsurvivors till they survived. Ultrasonography of the abdomen was carried out in all to find swelling of the pancreas. Computerized tomography was undertaken in those who had a swollen pancreas or whose serum amylase levels were elevated significantly (≥800 S.U). Of the 86 patients enrolled, 79 were taken up for analysis as data were incomplete in 7. Of the 79 patients, serum amylase was found to be elevated that is, >200 S.U. in 37 patients (46.95%). In three patients it was 800 S.U. One of them showed swollen pancreas on ultrasonography, which was confirmed by computerized tomography. This patient had ingested propoxyfur. In the other two patients, evidence of acute pancreatitis was not observed (on autopsy in one who died and on imaging in the other who survived). They had ingested chlorpyriphos. There was no significant correlation between the nature of the compounds (organophosphate or carbamates), inhibition of serum BUChE at admission, duration and severity of cholinergic syndrome and increase and time course of increase in serum amylase. Except for fenthion, significant persistent increase in serum amylase was not observed with individual compounds. The other associated abnormalities were polymorphonuclear leukocytosis (TLC >11 000/cumm) in all 37 patients who had elevated amylase, hyperglycemia (6/37) and, elevated transaminases (6/37). Mild elevation of serum amylase is common in patients with anticholinesterase poisoning. However, acute pancreatitis is rare. Human & Experimental Toxicology (2007) 26, 467—471
Escitalopram ingestions reported to Texas poison control centers, 2002—2005
Authors: Forrester M.B.
Published: August 2007

Limited information exists on potentially adverse escitalopram ingestions reported to poison control centers. Using isolated escitalopram ingestions reported to Texas poison control centers during 2002—2005, the proportion of cases involving serious medical outcomes was determined for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI). Of 1179 cases identified, 234 (20%) involved serious outcomes. Serious outcomes were significantly more likely to occur with a maximum dose of >100 mg (RR 4.69, CI 2.52—9.29) or >5 tablets (RR 4.96, CI 2.94—8.93), where the circumstances of the exposures involved self-harm or malicious intent (RR 3.21, CI 2.42—4.29), or when the patient was already at or en route to a health care facility when the poison control center was contacted (RR 7.88, CI 4.31—15.79) or referred to a health care facility by the poison control center (RR 15.91, CI 8.78—31.64). The severity of the outcome associated with isolated escitalopram ingestions depended on the dose and the circumstances of the ingestion. The management of patients with serious outcomes were more likely to involve health care facilities. Such information is useful for creating triage guidelines for the management of escitalopram ingestions. Human & Experimental Toxicology (2007) 26 , 473—482
Modal Analysis of a Beam with Radiation Damping: Numerical and Experimental Results
Authors: Pau Annamaria , Vestroni Fabrizio
Published: August 2007

In large structures, the excitation energy produced by an impact force may not be sufficient to spread throughout the structure and excite global modes. Thus, one may be interested in the dynamic characterization of the excited part of the structure by taking into consideration the wave propagation through its boundaries. This radiation damping is a source of local damping and, as a consequence, causes modal complexity. The spectral element method is adopted here to describe the modal characteristics of a system with radiation damping. A semi-infinite Euler-Bernoulli beam, whose span is interrupted by a spring with translational and rotational stiffness, is used as an example to illustrate the main features of the phenomenon characterized by modal complexity and to obtain a simple but meaningful experimental confirmation. This method could be useful in the modal characterization of a part of a structure.
Vibration Suppression of Nonlinear Rotor Systems Using a Dynamic Damper
Authors: Ishida Yukio , Inoue Tsuyoshi
Published: August 2007

Due to the inevitable imbalance of rotating machinery, resonance occurs when the rotational speed is in the vicinity of the critical speed. A rotor system supported by a single-row deep groove ball bearing shows nonlinear spring characteristics due to the clearance of bearings. In this article, passive vibration control of nonlinear rotor systems using a dynamic damper is studied. Theoretical analysis is performed to investigate the influence of nonlinearity on the vibration characteristics of controlled rotor systems, and the theoretical results obtained are confirmed by experiments. An example shows that the fixed-point theorem for optimization of the dynamic damper cannot be used when the rotor system has an isotropic symmetrical nonlinearity. The Newton-Raphson method is used to determine the optimal parameters of the dynamic damper for the nonlinear rotor, and passive vibration control utilizing the dynamic damper is achieved in the nonlinear rotor system.
Inverse Approach to the Reconstruction and Quantification of Vibratory Sources
Authors: Chiementin X. , Bolaers F. , Dron J.-P. , Rasolofondraibe L.
Published: August 2007

Vibratory analysis allows us to interpret the fundamental conditions of rotating machines. This interpretation is useful in the diagnosis of faults. In practice, the vibratory measurements made by sensors come from a mixture of vibratory sources corresponding to different machine components. Thus, it becomes hard to conduct state interpretation for each individual component. This fact leads us to consider the inverse problem, reconstruction of the vibratory sources based on measurements. However, the inversion is unfortunately unstable. To limit the instability, previous studies proposed use of a large number of sensors and the processing of measurements using regularization methods. However, regularization requires estimation of the regularization parameter, which is a hard task. In addition, regularization can remove some vibratory sources. Moreover, the sensor positions are “random”, but the stability is significantly influenced by the sensor positions and by the mixture properties described by modal analysis. This article proposes to link modal analysis and stability. This link allows us to reduce the number of sensors and to avoid regularization methods. Thus, two complementary approaches are developed to determine optimal sensor positions: A numerical approach with a numerical updated model and an experimental approach using modal analysis. Thanks to the use of these optimal positions, stability is improved and vibratory sources are correctly reconstructed.
Vibrations of an Anisotropic Plate Under Fluid Flow in a Channel
Authors: Korbahti B. , Uzal E.
Published: August 2007

An analytical solution is given for the eigenfrequencies of the vibrations of a generally orthotropic plate placed in a rigid channel of rectangular cross section through which fluid flows. The fluid flow, assumed to be inviscid, compressible and non-steady, is modeled using a linearized potential equation. The plate is simply supported along the channel and extends indefinitely; its vibrations are also assumed to be linear. The resulting system of partial differential equations are simplified assuming a travelling wave mode along the plate. The problem is reduced to a single integro-differential equation and solved analytically to obtain an algebraic eigenvalue equation relating travelling wavespeed to wavelength and the velocity of fluid flow. It is found that, for the case of a composite plate within a duct, placing the strengthening fibers perpendicular to flow direction increases the minimum velocity at which the unstable oscillations will occur in most cases.
Active Vibration Suppression of a Smart Flexible Beam Using a Sliding Mode Based Controller
Authors: Song G. , Gu H.
Published: August 2007

This article investigates robust active vibration suppression of a flexible beam with a low dominant frequency using piezoceramic sensor and actuators. The piezoceramic sensor and actuators are in patch form and are surface-bonded to the cantilevered end of the flexible beam. The robust sliding mode control, which has the advantages of being robust to plant parameter variation, insensitive to the unmodeled dynamics, and easy to implement, is adopted in this article for active vibration control of the flexible beam. Unlike other commonly used vibration suppression methods, such as positive position feedback control, strain rate feedback control, and lead compensation, the sliding mode controller requires almost no knowledge of the flexible beam. To avoid the chattering problem commonly associated with sliding mode control, a smooth switching function employing a hyperbolic tangent function is used. A low pass filter is applied to the output of the sliding mode controller to avoid excitation of the higher modes of the flexible beam. To demonstrate the advantage of sliding mode based active vibration reduction, its experimental results are compared with those of Proportional plus Derivative (PD) control and lead compensation. The comparison shows that the sliding mode controller reduces vibration of the flexible beam much more rapidly. To verify the robustness of the proposed sliding mode controller, vibration suppression of the beam is conducted for a case where the modal frequency of the beam is changed by adding masses. In addition, vibration suppression of the beam when subjected to a multi-modal excitation is also conducted. Experimental results demonstrate the robustness of the proposed controller with respect to varying model parameters and even the dynamics of higher modes.
Patterns of Injuries
Authors: Allen Terry , Novak Shannon A. , Bench Lawrence L.
Published: August 2007

This study uses two types of independent variables, age and the location of the physical wound, to develop a model of injury patterning that identifies violent behavior without direct observation of the assault. In this research, domestic violence injuries are compared to accidental injuries. The results indicate that there are specific and predictable injury patterns that separate abuse from other kinds of wounds. A logistic regression model was developed to identify the regions of the body most susceptible to injury from domestic assault. Using the age of the victim and the injury regions, probabilities were calculated to determine which wounds were caused by abuse.
Characterisation of Fiber Obtained from Pumpkin (cucumis moschata duch.) Mesocarp Through Enzymatic Treatment
Authors: Fissore E.N. , Ponce N.M. , Stortz C.A. , Rojas A.M. , Gerschenson L.N.
Published: August 2007

Cell wall-enriched pumpkin ( Cucumis moschata Duch.) powder was submitted to enzymatic hydrolysis by cellulase or hemicellulase in order to evaluate the performance of these cell wall-degrading enzymes on that substrate. Different enzyme-substrate ratios were evaluated and the effect exerted by the buffer on cell wall polysaccharides. Cellulase produced the release of pectin macromolecules which include homogalacturonans side chains, the rhamnogalacturonan I core and rhamnogalacturonan II, in conjunction with xylogalacturonans. The content of galacturonic acid in product obtained ranged from 545 to 781 g/kg of fiber. Hemicellulases produced intense pectin hydrolysis leading to fiber-fractions with galacturonic acid contents ranging from 390 to 444 g/kg of fiber and enriched in glucose polymers as the enzyme proportion increased. Few rhamnogalacturonan-I was present.The acidic citrate buffer (pH 5.2) used for allowing enzyme activity could per se remove noncovalent cross-links like ionic bonds. As a consequence, pectin-in-extensin entanglements, pectins joined by Ca2+-bridges through the homogalacturonan side chains, and some pectins that are originally soluble in cold water due to little or no binding to the cell wall, could be removed by this citrate buffer. Enzymatic hydrolysis as well as buffer extraction produced fiber-products with an important thickening effect of aqueous systems. This effect was smaller as the ratio enzyme-substrate was increased and, in general, the fiber fractions isolated produced an in vitro glucose diffusion retardation.
Low Molecular Weight Phenolic and Anthocyanin Composition of Grape Skins from cv. Syrah (Vitis vinifera L.) in the Maipo Valley (Chile): Effect of Clusters Thinning and Vineyard Yield
Authors: Peña-Neira A. , Cáceres A. , Pastenes C.
Published: August 2007

Changes in phenolic composition were determined in cv. Syrah-vines grape skins during ripening for two contrasting yields, resulting from cluster thinning at veraison. Treatments consisted on 16 and eight clusters per plant leading to approximately 8 ton/ha (T1) and 4 ton/ha (T2). In the grape skins of the samples analysed, 11 different low molecular weight phenolic compounds were identified, as well as 15 anthocyanins. Cluster thinning had a minimal effect on ripening time and weight of grape skins, however, clusters from low yield plants resulted in a lower total acidity and slightly higher pH. As for the phenylpropanoid pathway, the flavan-3-ol (+)-catechin, and the flavanols isorhamnetin-3- O-galactoside and isorhamnetin-3- O-glucoside, resulted in a higher concentration in berry skins from low yield plants. It is concluded that cluster thinning may result, from the oenological point of view, in an increased grape quality especially in compounds related to wine colour.
Iron Bioavailability from Pate Enriched with Encapsulated Ferric Pyrophosphate or Ferrous Gluconate in Rats
Authors: Navas-Carretero S. , Pérez-Granados A.M. , Sarriá B. , Schoppen S. , Vaquero M.P.
Published: August 2007

Fortifying food with iron has been widely studied as a strategy to prevent iron deficiency anaemia. This work comparatively assessed the bioavailability of two forms of iron, ferrous gluconate or ferric pyrophosphate encapsulated in liposomes (lipofer®), when used as fortificants in meat pate. Three groups of growing rats consumed during 28 days either a control diet (AIN-93G), or two diets prepared with enriched pate as the unique source of iron and fat. Body weight and diet intake were measured weekly, and during the last week faeces were collected. On day 28 animals were sacrificed, livers and spleens were removed and stored. Haemoglobin and total iron binding capacity (TIBC) were determined. There were not significant differences among the three groups in body weight and apparent iron absorption, although food intake in the two pate groups was significantly higher compared to the control group. There were not differences in liver and spleen iron content and concentration, neither in haemoglobin and TIBC values. These results indicated that iron bioavailability of pate enriched with ferrous gluconate or ferric pyrophosphate encapsulated in liposomes was similar, and thus both sources of iron are good candidates to be used as fortifiers in meat based products. The present outcome needs to be validated in humans.
Effects of Consumption of Maillard Reaction Products on Magnesium Digestibility and Tissue Distribution in Rats
Authors: Delgado-Andrade C. , Seiquer I. , Navarro M.P.
Published: August 2007

Magnesium bioavailability could be affected by the presence of Maillard reaction products (MRP), formed during the heat processing of foods. The aim of this study was to analyze the influence of the consumption of MRP, derived from glucose-methionine (GM) mixtures heated for 30 min, on magnesium bioavailability and tissue distribution. Magnesium balances (whole experimental period and final week) were performed in rats. Animals were sacrificed and certain organs removed to analyse the magnesium content. In the experimental group, consumption of the heated GM mixture increased magnesium digestibility during the last week of the assay (72.1 ± 2.4%) compared with the control group (59.4 ± 1.3%); this variation was associated with MRP consumption and not with the residual methionine. However, no variations were found in magnesium bioavailability over the whole experimental period. The magnesium content in the femur was lower in the animals fed the MRP-diet than in the control group (0.67 ± 0.03 vs 0.86 ± 0.03 mg) but its concentration was higher in unusual deposits such as the liver and the kidney. Our results show that long-term dietary consumption of MRP could lead to alterations in bone health, which could contribute to the development and advance of degenerative bone diseases associated with aging.
A Review and Examination of Demographic Similarity Measures Used to Assess Relational Demography Within Groups
Authors: Riordan Christine M. , Wayne Julie Holliday
Published: August 2007

Relational demography within groups, or an individual's demographic similarity to a group, is a type of cross-level theory labeled as an individual-within-the-group model. Previous researchers used three different approaches for measuring the core construct of demographic similarity: the difference score, interaction term, and perceptual approaches. This article provides an in-depth review of the measurement definition, conceptual properties, and limitations of each approach, highlighting similarities and differences among them. Then, the authors use data from four financial service organizations to demonstrate that the three measures minimally relate to one another and differentially relate to work outcomes. Although researchers often use the three measures interchangeably, this article suggests that they assess distinct components of the demographic similarity construct or measure the construct with differing degrees of success. Based on the review, the authors offer best-practice guidelines for researchers as to how to use each approach most effectively.
The Philosophy and Politics of Quality in Qualitative Organizational Research
Authors: Amis John M. , Silk Michael L.
Published: August 2007

Within this article, the authors outline the political and institutional structures that work to formulate operating norms that govern what is considered to be ``acceptable'' qualitative organizational research, and the quality indicators attached to foundational, quasi-foundational, and nonfoundational research orientations. They argue that encouraging a plurality of methods and representations will better position the field of organizational studies to address the most significant questions of our time. Located within this position, they call for a democratization of what counts in organizational research: a more considered and central space for nonhegemonic approaches to qualitative work. In so doing, they champion a moral-sacred epistemology that foregrounds ethical and moral concerns as underpinning both the purpose and the quality of the research.
Meta-Analyses
Authors: Dalton Dan R. , Dalton Catherine M.
Published: August 2007

The authors' role is to comment on the four articles that compose this feature topic of Organizational Research Methods on meta-analysis. In that spirit, the authors note the common themes addressed in this work and its contribution to a growing body of literature addressing pivotal aspects of meta-analyses. Also, the authors discuss some elements of meta-analysis that may account for its relatively infrequent use by organizational researchers. Last, the authors underscore other features of its use that may be unparalleled when compared to alternative analyses.
Investigation of Parameters Governing the Damage and Energy Absorption Characteristics of Honeycomb Sandwich Panels
Authors: Zhou G. , Hill M. , Hookham N.
Published: August 2007

Honeycomb sandwich panels of various skin thicknesses and core densities have been investigated under quasi-static loading in bending and indentation with both hemispherical (HS) and flat-ended (FE) indenters. Core crushing, top skin delamination, and top skin fracture are identified as major damage mechanisms. Their characteristics and energy-absorbing capabilities are established using load—displacement and load—strain curves and inspections of cross-sectioned specimens. The effects of varying skin thickness, core density and type, indenter nose shape, and boundary conditions on the damage and energy-absorbing characteristics are examined. The variation of the indenter nose shape is shown to induce a change in the damage mechanisms and have the most significant effect on energy absorption, especially for panels with relatively thicker skins. Increasing the skin thickness significantly increases not only the initial threshold and ultimate loads but also the absorbed energy (AE) of the panels. Increasing the core density has a very small effect on either the ultimate loads or the energy-absorbing capacity, while the effect of the support conditions on the damage and energy-absorbing characteristics is small. The larger 220 mm diameter panels absorb significantly more energy than the 100 mm diameter panels because of the much greater ultimate displacement. Different core materials with a similar density show little difference in either the damage or the energy-absorbing characteristics due to the limited contribution of transverse shear resistance. Panels with a delaminated top skin have lower threshold loads under both indenters and lower ultimate load for the HS indenter.
Development of a Damage Detection Scheme Applicable to Sandwich Composites
Authors: Just-Agosto F. , Shafiq B. , Serrano D.
Published: August 2007

Minor impacts, perforations, and debonding damages in sandwich composites are studied using two vibration (mode shape curvature and damping matrix identification) and two transient temperature response (geometrical interpretation of convex hulls and thermographic heat patterns) based techniques. This research asserts that the best approach for damage detection in sandwich composites is the strategic combination of complementary damage detection techniques and that a properly trained neural network (NN) scheme can enormously facilitate the diverse data processing and damage source prediction. Although all four techniques resulted in successful damage detection, however, based on the robustness and promise in actual service implementation, only the results of the mode shape curvature and thermographic heat patterns were implemented into a properly trained NN. The article outlines the techniques and methodologies used and lessons learned in the damage detection of sandwich composites.
Barriers to high-school completion among immigrant and later-generation Latinos in the USA
Authors: Lutz Amy
Published: August 2007

This article examines high-school completion among key Latino immigration groups in the USA, with a particular focus on the impacts of ethnicity, generation, language proficiencies, family structure and socioeconomic status. Family socioeconomic status has by far the largest impact on high-school completion. Poverty presents a persistent and daunting problem in high-school non-completion in the USA and is a primary contributor to Latino high-school non-completion. Addressing the issue of poverty is particularly important in the case of Mexicans, who make up the largest proportion of the immigrant population and whose levels of high-school completion are significantly lower than those of other groups. This research also highlights the impact of Spanish maintenance on high-school completion and indicates that high-level proficiency in both Spanish and English is associated with a greater likelihood to complete high school than Non-Hispanic whites when controlling for socioeconomic status and other variables. Ultimately, an important message of this research is that the impact of socioeconomic status on high-school completion — a primary mechanism for socioeconomic mobility across generations — must not be understated or overlooked by policymakers who aim to address social mobility across generations of immigrant groups in the USA.
New differences, old explanations
Authors: Fekjær Silje Noack
Published: August 2007

A B S T R AC T The aim of this article is to improve current understanding of the educational differences between minority groups in Norway who differ by country of origin. How much of these educational differences can be explained by the traditional explanation of social background? Further, is the effect of social background dependent on ethnic background? These questions are examined through analyses of register data containing information on all persons in Norway born between 1965 and 1981. Second-generation minority groups with Pakistani, Turkish and Indian background are compared with the majority. The conclusion is that social background explains some of the differences in educational outcomes, in particular the relatively low educational attainment of the groups of Turkish and Pakistani background. However, social background provides a less relevant explanation of the relatively high attainment of the group with Indian background and, compared to the majority, social background appears to be less important for educational choices among minority youth.
Ethnicity, schooling, and merit in the Netherlands
Authors: Van De Werfhorst Herman G. , Van Tubergen Frank
Published: August 2007

A B S T R A C T We examine to what extent ethnicity affects academic ability measured in the first year of secondary school and secondary school type in the Netherlands. We focus on second-generation immigrants. The empirical results indicate that academic ability (both in mathematics and language) is not affected by ethnicity, independent of parents' occupation, education, and resources. On a bi-variate level, children of Turkish and Moroccan immigrants in the Netherlands are found relatively often in lower tracks in secondary school. This relationship is fully driven by social class and merit, operationalized as including ability and effort. Moreover, children of Turkish, Surinamese and Antillean migrants are, relative to Dutch children from similar backgrounds and merit, more often found in higher tracks in secondary school. However, given the very skewed distribution of educational attainment of immigrants, it is questionable whether `class versus ethnicity models' can accurately compare achievements of native and immigrant children in the Netherlands.
The school careers of ethnic minority youth in France
Authors: Brinbaum Yaël , Cebolla-Boado Hector
Published: August 2007

This article explores the educational performance and careers of the children of immigrant families and those of French natives in secondary schooling in France. Using a rich longitudinal dataset (the 1995 Panel of the Ministry of Education), we compare the parents' educational expectations with the school careers of their children. We identify higher educational expectations among immigrant parents than among natives from a similar social background. Although immigrant students begin the collège with a poorer school performance than native students, they tend to shorten this distance with the simple passage of time. Besides, most of this disadvantage is explained by class-related factors. Among the working class, there are few differences in the educational careers of children of immigrants and those of French-born children in upper secondary education. Nonetheless, students from a North African ancestry seem to be less able to materialize their aspirations than the descendants of Portuguese immigrants, and thus express more frequently their dissatisfaction with their orientation in the vocational or technological track.
A Leaching Type Antibacterial Agent in the Easy-care Finishing of Knitted Cotton Fabric
Authors: Abo-Shosha M.H. , El-Hosamy M.B. , Hashem A.M. , El-Nagar A.H.
Published: August 2007

A leaching type antibacterial agent (namely Tinosan® CEL) is incorporated in an easy-care finishing formulation of knitted cotton fabric. Finishing is conducted at different conditions including type of softener (Solusoft® WA 90ET, Leomin® NI-ET, Ultratex® 7723, Sapamin® KLNEW, and Siligen® TX 2490), crosslinker (Arkofix® NG-ET, Fixapret® CPN, and Knittex® FEL), and catalyst (Knittex® Catalyst Mo, NH4Cl, MgCl2 . 6H2O, and ZnSO4) as well as concentrations of `Knittex® FEL/ZnSO4' and Tinosan® CEL besides curing time and temperature. It is found that optimal additives to Tinosan® CEL that afford maximum overall antibacterial activities (against Staphylococcus aureus and Pseudomonas aeruginosa) and hydrophilicity to the fabric finished by the pad-dry-cure method (100% wet pick up; drying at 100°C/5 min; curing at 160°C/5 min) were: Knittex® FEL (50 g/L)/ ZnSO4 (5 g/L) and Siligen® TX2490 (20 g/L) along with a wetting agent (2 g/L) and acetic acid (1 g/L). The impact of Tinosan® CEL alone (bath I), coupled with Siligen® TX2490 (bath II), or both in combination with Knittex® FEL/ZnSO4 (bath III) on whiteness index, surface roughness, drape coefficient, air permeability, bursting strength, abrasion resistance, and crease recovery angle of the fabric is investigated. Analysis of variance (ANOVA) of data obtained is carried out at P-value ≤ 0.05. Moreover, the effect of Tinosan® CEL concentration in bath III on these properties is also studied. Durability of antibacterial activity, expressed as inhibition clear zone, using 10 g/L of Tinosan® CEL in bath I or II continues to 10 washing cycles. However, treatment with bath III attains durability even after 25 washing cycles.
Effect of Nozzle Geometry on the Flow Dynamics of Hydroentangling Jet
Authors: Wang Caihua , Jin Xiangyu , Wang Shanyuan
Published: August 2007

Hydroentangling technique uses extremely fine nozzles to direct high-energy water jets against a loose fiber web. This study investigates the effect of nozzle geometry on the flow dynamics of hydroentangling jet by simulating water-jet formation from cone-up, streamline, and cone-down geometries. The simulation results reveal that water contacts with the nozzle wall all the way when it goes through the cone-up and streamline nozzles. In contrast, the cone-down geometry can form a constricted water-jet because of a sharp turning angle at the nozzle entrance. Consequently, the cone-down nozzle has higher velocity coefficient and the water-jet discharged from the nozzle has a longer intact length than the two others because of the absence of cavitation and wall friction. Part of the results is in excellent agreement with earlier experimental studies.
Investigation on the Radar Absorption Properties of Carbon Fiber Containing Nonwovens
Authors: Zhu Hua , Zhang Jianchun , Chen Pïng , Wang Xiangcheng
Published: August 2007

Nonwovens containing pitch-based carbon fiber (PCF), polyester fiber, or wool fiber with thermo-bonding fiber 4080 as the bonding agent are fabricated by the through-air thermal bonding process. The volume fraction of carbon fiber in the nonwovens ranges from 0 to 1.5%. Radar wave absorbing properties of the nonwovens are investigated by the far-field RCS measurement in the frequency range from 8 to 18 GHz. Results of the measurement indicate that the radar-absorbing capacity of the nonwovens is closely related to the volume fraction of carbon fiber in the nonwovens and the thickness of the nonwovens, regardless of the types of fiber except PCF in the nonwovens. When the thickness of the nonwovens is 10 mm, radar-absorbing capacity of the nonwovens varies with the content of PCF and reaches the maximum around the PCF volume fraction of 0.036%. When the thickness of the nonwoven with the PCF volume fraction of 0.036% is 6 mm, there appears an absorption peak on the curve of reflectivity at the frequency around 11 GHz, and the absorption in the whole frequency range from 8 to 18 GHz is intensified. Electromagnetic parameters of the component fibers in the nonwovens are tested by the coaxial transmission line method andthe radar absorption characteristics of the nonwovens are explained on the basis of the electromagnetic properties of these fibers.
Compaction Behavior of Assembled Fiber Reinforced Preforms
Authors: Ogale A. , Mitschang P.
Published: August 2007

Preform engineering aspects and tailored reinforcements are solely related to liquid composite molding (LCM) process (Mitschang, P., Ogale, A., Schlimbach, J., Weyrauch, F. and Weimer, C. (2003). Preform Technology: A Necessary Requirement for Quality Controlled LCM-Processes, Polym. & Polym. Compos., 8(11): 605—622; Weimer, C. and Mitschang, P. (2002). Continuous Manufacturing of Tailored Reinforcements for Liquid Infusion Processes Based on Stitching Technologies, In: Proceedings of the 6th International Conference on Flow Processes in Composite Materials, Auckland, New Zealand). In order to reduce the process time to manufacture fiber reinforced polymer composites (FRPC), it is essential to reduce tool loading time. Utility cost, forces acting on the preform geometry during the LCM process, stitch pattern, and stitch formation have to be taken into consideration. Sewn preform geometries have its own compression properties and therefore behaves differently in terms of processing and mechanical performance. To understand this relationship, it is essential to relate sewing parameters with the LCM processing parameters. The current work is based on the experimental analysis of preforms with three different sewing parameters: thread tension, presser-foot height, and stitch density. Thread tension and presser-foot pressure causes considerable changes in the compaction behavior of the preform. The stitching density which causes locking of the fiber bundle, influences the compaction phenomenon together with the thread tension and foot pressure. It is essential that stitches and stitching parameters required to be designed according to tool loading practices, compaction situations, and required final fiber volume fraction (Vf).
Constructing gene co-expression networks and predicting functions of unknown genes by random matrix theory
Authors: Luo Feng , Yang Yunfeng , Zhong Jianxin , Gao Haichun , Khan Latifur , Thompson Dorothea K , Zhou Jizhong
Published: August 2007

Background

Large-scale sequencing of entire genomes has ushered in a new age in biology. One of the next grand challenges is to dissect the cellular networks consisting of many individual functional modules. Defining co-expression networks without ambiguity based on genome-wide microarray data is difficult and current methods are not robust and consistent with different data sets. This is particularly problematic for little understood organisms since not much existing biological knowledge can be exploited for determining the threshold to differentiate true correlation from random noise. Random matrix theory (RMT), which has been widely and successfully used in physics, is a powerful approach to distinguish system-specific, non-random properties embedded in complex systems from random noise. Here, we have hypothesized that the universal predictions of RMT are also applicable to biological systems and the correlation threshold can be determined by characterizing the correlation matrix of microarray profiles using random matrix theory.

Results

Application of random matrix theory to microarray data of S. oneidensis, E. coli, yeast, A. thaliana, Drosophila, mouse and human indicates that there is a sharp transition of nearest neighbour spacing distribution (NNSD) of correlation matrix after gradually removing certain elements insider the matrix. Testing on an in silico modular model has demonstrated that this transition can be used to determine the correlation threshold for revealing modular co-expression networks. The co-expression network derived from yeast cell cycling microarray data is supported by gene annotation. The topological properties of the resulting co-expression network agree well with the general properties of biological networks. Computational evaluations have showed that RMT approach is sensitive and robust. Furthermore, evaluation on sampled expression data of an in silico modular gene system has showed that under-sampled expressions do not affect the recovery of gene co-expression network. Moreover, the cellular roles of 215 functionally unknown genes from yeast, E. coli and S. oneidensis are predicted by the gene co-expression networks using guilt-by-association principle, many of which are supported by existing information or our experimental verification, further demonstrating the reliability of this approach for gene function prediction.

Conclusion

Our rigorous analysis of gene expression microarray profiles using RMT has showed that the transition of NNSD of correlation matrix of microarray profile provides a profound theoretical criterion to determine the correlation threshold for identifying gene co-expression networks.
GSK-3 inhibitors induce chromosome instability
Authors: Tighe Anthony , Ray-Sinha Arpita , Staples Oliver D , Taylor Stephen S
Published: August 2007

Background

Several mechanisms operate during mitosis to ensure accurate chromosome segregation. However, during tumour evolution these mechanisms go awry resulting in chromosome instability. While several lines of evidence suggest that mutations in adenomatous polyposis coli (APC) may promote chromosome instability, at least in colon cancer, the underlying mechanisms remain unclear. Here, we turn our attention to GSK-3 – a protein kinase, which in concert with APC, targets β-catenin for proteolysis – and ask whether GSK-3 is required for accurate chromosome segregation.

Results

To probe the role of GSK-3 in mitosis, we inhibited GSK-3 kinase activity in cells using a panel of small molecule inhibitors, including SB-415286, AR-A014418, 1-Azakenpaullone and CHIR99021. Analysis of synchronised HeLa cells shows that GSK-3 inhibitors do not prevent G1/S progression or cell division. They do, however, significantly delay mitotic exit, largely because inhibitor-treated cells have difficulty aligning all their chromosomes. Although bipolar spindles form and the majority of chromosomes biorient, one or more chromosomes often remain mono-oriented near the spindle poles. Despite a prolonged mitotic delay, anaphase frequently initiates without the last chromosome aligning, resulting in chromosome non-disjunction. To rule out the possibility of "off-target" effects, we also used RNA interference to selectively repress GSK-3β. Cells deficient for GSK-3β exhibit a similar chromosome alignment defect, with chromosomes clustered near the spindle poles. GSK-3β repression also results in cells accumulating micronuclei, a hallmark of chromosome missegregation.

Conclusion

Thus, not only do our observations indicate a role for GSK-3 in accurate chromosome segregation, but they also raise the possibility that, if used as therapeutic agents, GSK-3 inhibitors may induce unwanted side effects by inducing chromosome instability.
Technology to accelerate pangenomic scanning for unknown point mutations in exonic sequences: cycling temperature capillary electrophoresis (CTCE)
Authors: Ekstrøm Per O , Bjørheim Jens , Thilly William G
Published: August 2007

Background

Rapid means to discover and enumerate unknown mutations in the exons of human genes on a pangenomic scale are needed to discover the genes carrying inherited risk for common diseases or the genes in which somatic mutations are required for clonal diseases such as atherosclerosis and cancers. The method of constant denaturing capillary electrophoresis (CDCE) permitted sensitive detection and enumeration of unknown point mutations but labor-intensive optimization procedures for each exonic sequence made it impractical for application at a pangenomic scale.

Results

A variant denaturing capillary electrophoresis protocol, cycling temperature capillary electrophoresis (CTCE), has eliminated the need for the laboratory optimization of separation conditions for each target sequence. Here are reported the separation of wild type mutant homoduplexes from wild type/mutant heteroduplexes for 27 randomly chosen target sequences without any laboratory optimization steps. Calculation of the equilibrium melting map of each target sequence attached to a high melting domain (clamp) was sufficient to design the analyte sequence and predict the expected degree of resolution.

Conclusion

CTCE provides practical means for economical pangenomic detection and enumeration of point mutations in large-scale human case/control cohort studies. We estimate that the combined reagent, instrumentation and labor costs for scanning the ~250,000 exons and splice sites of the ~25,000 human protein-coding genes using automated CTCE instruments in 100 case cohorts of 10,000 individuals each are now less than U.S. $500 million, less than U.S. $500 per person.