bluuebunny/crossref_metadata_2025 huggingface dataset:
FULL AND PART-TIME ENTREPRENEURSHIP AND THE SUPPLY OF ENTREPRENEURIAL EFFORT: EVIDENCE FROM MEXICAN MICROENTERPRISES
Authors: MUNGARAY ALEJANDRO , RAMIREZ-URQUIDY MARTIN
Published: February 2012

This paper aims to study the influence of pecuniary and non-pecuniary aspects on entrepreneurship. It attempts to fill a gap in terms of explaining how these aspects determine individual and household choices or constraints regarding entering entrepreneurship as either part time, with participation in labor markets, or as full time, as well as the corresponding supply of entrepreneurial effort. The study searches for insights on the relation between motivations intrinsic in either form of entrepreneurship and their effects on the supply of the entrepreneurial effort. Part-time micro entrepreneurs respond more to non-pecuniary aspects when maximizing their life choices, which divert them from profit maximization. However, full-time micro entrepreneurs are more sensitive to pecuniary factors and their choices regarding utility maximization are more compatible with profit maximization, albeit both groups are part of simple forms of entrepreneurship. The results identify the expectations placed on enterprises run by part-time and full-time entrepreneurial households in terms of their motivation and attitude toward the goal of profit making and consequently, to entrepreneurial supply and performance. Both groups may be relevant from the policy standpoint and employment in developing economies.
Effect of ghrelin on glucose regulation in mice
Authors: Chacko Shaji K. , Haymond Morey W. , Sun Yuxiang , Marini Juan C. , Sauer Pieter J. J. , Ma Xiaojun , Sunehag Agneta L.
Published: February 2012

Improvement of glucose metabolism after bariatric surgery appears to be from the composite effect of the alterations in multiple circulating gut hormone concentrations. However, their individual effect on glucose metabolism during different conditions is not clear. The objective of this study was to determine whether ghrelin has an impact on glycogenolysis, gluconeogenesis, and insulin sensitivity (using a mice model). Rate of appearance of glucose, glycogenolysis, and gluconeogenesis were measured in wild-type (WT), ghrelin knockout (ghrelin−/−), and growth hormone secretagogue receptor knockout (Ghsr−/−) mice in the postabsorptive state. The physiological nature of the fasting condition was ascertained by a short-term fast commenced immediately at the end of the dark cycle. Concentrations of glucose and insulin were measured, and insulin resistance and hepatic insulin sensitivity were calculated. Glucose concentrations were not different among the groups during the food-deprived period. However, plasma insulin concentrations were lower in the ghrelin−/− and Ghsr−/− than WT mice. The rates of gluconeogenesis, glycogenolysis, and indexes of insulin sensitivity were higher in the ghrelin−/− and Ghsr−/− than WT mice during the postabsorptive state. Insulin receptor substrate 1 and glucose transporter 2 gene expressions in hepatic tissues of the ghrelin−/− and Ghsr−/− were higher compared with that in WT mice. This study demonstrates that gluconeogenesis and glycogenolysis are increased and insulin sensitivity is improved by the ablation of the ghrelin or growth hormone secretagogue receptor in mice.
Intraneuronally injected amyloid beta inhibits long-term potentiation in rat hippocampal slices
Authors: Nomura Izumi , Takechi Hajime , Kato Nobuo
Published: February 2012

Extracellular accumulation of amyloid beta (Aβ) is a hallmark of Alzheimer's disease (AD). It has been reported that extracellular perfusion of Aβ inhibits long-term potentiation (LTP), which is strongly related to memory in animal models. However, it has recently been proposed that intracellular Aβ may be the first pathological change to occur in AD. Here, we have investigated the effect on LTP of intracellular injection of Aβ (Aβ1–40, Aβ1–42) into hippocampal pyramidal cells using patch-clamp technique. We found that injection of 1 nM Aβ1–42 completely blocked LTP, and extracellular perfusion of a p38 MAPK inhibitor or a metabotropic glutamate receptor blocker reversed these blocking effects on LTP. Furthermore, we have examined the effects of different concentrations of Aβ1–40 and Aβ1–42 on LTP and showed that Aβ1–40 required a 1,000-fold higher concentration to attenuate LTP than 1 nM Aβ1–42. These results indicate that LTP is impaired by Aβ injected into genetically wild-type neurons in the sliced hippocampus, suggesting an acute action of intracellular Aβ on the intracellular LTP-inducing machinery.
Spatial variation in membrane excitability modulated by 4-AP-sensitive K+ channels in the axons of the crayfish neuromuscular junction
Authors: Lin Jen-Wei
Published: February 2012

Current-clamp recordings were made from the primary (1°) and secondary (2°) branching points (BPs) of axons at the crayfish neuromuscular junction. Action potential (AP) firing initiated by current injected at the 2° BP showed strong adaptation or high-frequency firing at threshold current, whereas AP firing frequency at the 1° BP exhibited a gradual rise with increasing current amplitude. The voltage threshold for AP ( VTH) was higher at the 2° BP than the 1° BP. 4-Aminopyridine (4-AP) at 200 μM increased AP amplitude and duration at both BPs but reduced threshold current at the 2° BP more than at the 1° BP. This blocker lowered VTH at both BPs, but the difference between the BPs remained. Firing patterns evoked at the 2° BP became similar to those evoked at the 1° BP in 4-AP. Thus 4-AP-sensitive channels may be more concentrated in the distal axon and control AP initiation and firing patterns there. Orthodromic APs between the two BPs were also compared. There was no difference in AP amplitude between the two BPs, but AP half-width recorded at the 2° BP was longer than that at the 1° BP. AP duration at both BPs increased gradually, by ∼17%, during a 100-Hz, 500-ms train (in-train rise). Normalized AP half-widths revealed a smaller fractional in-train rise at the 2° BP. Thus, although distal APs were broader, AP duration there was under more stringent control than that of the proximal axon. 4-AP increased AP amplitude and duration of the entire orthodromic train and reduced the magnitude of the in-train rise in AP half-width at both BPs. However, this blocker did not uncover a clear difference between the two BPs. Thus 4-AP-sensitive channels concentrated in distal axon may be essential in preventing unintended firing and modulating AP waveform without interfering with orthodromic AP propagation.
Physiology of afferent neurons in larval zebrafish provides a functional framework for lateral line somatotopy
Authors: Liao James C. , Haehnel Melanie
Published: February 2012

Fishes rely on the neuromasts of their lateral line system to detect water flow during behaviors such as predator avoidance and prey localization. Although the pattern of neuromast development has been a topic of detailed research, we still do not understand the functional consequences of its organization. Previous work has demonstrated somatotopy in the posterior lateral line, whereby afferent neurons that contact more caudal neuromasts project more dorsally in the hindbrain than those that contact more rostral neuromasts (Gompel N, Dambly-Chaudiere C, Ghysen A. Development 128: 387–393, 2001). We performed patch-clamp recordings of afferent neurons that contact neuromasts in the posterior lateral line of anesthetized, transgenic larval zebrafish ( Danio rerio) to show that larger cells are born earlier, have a lower input resistance, a lower spontaneous firing rate, and tend to contact multiple neuromasts located closer to the tail than smaller neurons, which are born later, have a higher input resistance, a higher spontaneous firing rate, and tend to contact single neuromasts. We suggest that early-born neurons are poised to detect large stimuli during the initial stages of development. Later-born neurons are more easily driven to fire and thus likely to be more sensitive to local, weaker flows. Afferent projections onto identified glutamatergic regions in the hindbrain lead us to hypothesize a novel mechanism for lateral line somatotopy. We show that afferent fibers associated with tail neuromasts respond to stronger stimuli and are wired to dorsal hindbrain regions associated with Mauthner-mediated escape responses and fast, avoidance swimming. The ability to process flow stimuli by circumventing higher-order brain centers would ease the task of processing where speed is of critical importance. Our work lays the groundwork to understand how the lateral line translates flow stimuli into appropriate behaviors at the single cell level.
Factor V Leiden and Prothrombin 20210A Mutations among Turkish Pediatric Leukemia Patients
Authors: Akın Dilara Fatma , Sipahi Kadir , Kayaalp Tuğba , Eğin Yonca , Taşdelen Serpil , Kürekçi Emin , Ezer Üstün , Akar Nejat
Published: February 2012

This study was undertaken to determine the prevalence of the Factor V 1691 G-A and PT 20210 G-A mutations in Turkish children with leukemia. We genotyped 135 pediatric leukemia patients with for these mutations. Eleven (8%) of the 135 patients were heterozygous for the FV 1691 G-A mutation. Seven (5,1%) of the patients carried the PT 20210 G-A heterozygous mutation. Of the 135 patients, only three had thrombotic event, none of which had these two mutations, which is common in Turkish population. Our findings revealed a controversial compared to the previous reports, which needs further investigation.
Gait and Function in Class III Obesity
Authors: Ling Catherine , Kelechi Teresa , Mueller Martina , Brotherton Sandra , Smith Sheila
Published: February 2012

Walking, more specifically gait, is an essential component of daily living. Walking is a very different activity for individuals with a Body Mass Index (BMI) of 40 or more (Class III obesity) compared with those who are overweight or obese with a BMI between 26–35. Yet all obesity weight classes receive the same physical activity guidelines and recommendations. This observational study examined the components of function and disability in a group with Class III obesity and a group that is overweight or has Class I obesity. Significant differences were found between the groups in the areas of gait, body size, health condition, and activity capacity and participation. The Timed Up and Go test, gait velocity, hip circumference, and stance width appear to be most predictive of activity capacity as observed during gait assessment. The findings indicate that Class III-related gait is pathologic and not a normal adaptation.
Adolescents' Perceptions of Their Consent to Psychiatric Mental Health Treatment
Authors: Roberson Anthony James , Kjervik Diane K.
Published: February 2012

The purpose of this paper is to present the findings of a small-scale study in which the decision-making process of adolescents who consent to psychiatric mental health treatment was examined. Sixteen (16) adolescents were interviewed about their decisions related to initial and continued treatment, along with their understanding of minor consent laws. Interviews were audio-recorded, and transcripts were analyzed through concept analysis. Findings are presented in the context of the decision-making steps and research questions. Most adolescents did not recognize consequences related to psychiatric mental health treatment and did not assimilate and integrate information provided to them about treatment choices. Adolescents disagreed with current minor consent laws that allow minors to consent to certain healthcare treatments without the required consent of the parent. Further, adolescents reported that a collaborative approach in making decisions about the adolescent’s psychiatric mental health treatment was most facilitative of achieving the goals of treatment.
The Specific Sagittal Magnetic Resonance Imaging of Intradural Extra-Arachnoid Lumbar Disc Herniation
Authors: Sasaji Tatsuro , Horaguchi Kiyoshi , Yamada Noboru , Iwai Kazuo
Published: February 2012

Intradural extra-arachnoid lumbar disc herniation is a rare disease. Few MRI findings have been reported. We experienced an intradural extra-arachnoid lumbar disc herniation. We reviewed the preoperative MRI findings. Lumbar spine T2-weighted sagittal MRI showed that one line of the ventral dura was divided into two by a disc herniation. We speculated that the two lines comprised the dura and arachnoid and that a disc herniation existed between them. We believe that division of the ventral dural line on T2-weighted sagittal images is a characteristic finding of intradural extra-arachnoid lumbar disc herniation. The division of ventral dural line seemed to be a “Y,” and, thus, we called it the “Y sign.” The “Y sign” may be useful for diagnosing intradural extra-arachnoid lumbar disc herniation.
The Expression of the Generalized Drazin Inverse of A − CB
Authors: Liu Xiaoji , Tu Dengping , Yu Yaoming
Published: February 2012

We investigate the generalized Drazin inverse of A − CB over Banach spaces stemmed from the Drazin inverse of a modified matrix and present its expressions under some conditions.
Amplification of the Capacitance Containing Nematic Liquid Crystal Embedded with Metal Nanoparticles
Authors: Kobayashi Shunsuke , Sakai Yoshio , Miyama Tomohiro , Nishida Naoto , Toshima Naoki
Published: February 2012

Herein, we report the dielectric properties of liquid crystal cells embedded with the nanoparticles of Pd, where each of which is covered with a diffusion cloud. It is shown that an amplification of the capacitors with these media occurs with the gain, Ac = 12.5, when the concentration of nanoparticles is 0.3 wt% and in the frequency region below the dielectric relaxation frequency, 158.5 Hz. This phenomenon is explained by an equivalent circuit model together with a compatible explanation of the dielectric strength and the relaxation time. It is claimed that the occurrence of the capacitance amplification may be attributed to a special nature of the oscillating extra charges, which appear in the region between the host medium and inclusion, and produces an effective negative dielectric constant of the special nanoparticles. This explanation was made by formulating an independent auxiliary equivalent circuit equation that enables to determine the numerical condition of the production of the negativity in the dielectric constant of inclusions (nanoparticles), and, thus, we succeeded in getting the numerical value of this dielectric constant and that of the gain of the capacitance amplification.
On Fixed Point Theorems in Intuitionistic Fuzzy Metric Spaces
Authors: Jiao Zhenhua
Published: February 2012

The author extends two fixed point theorems (due to Gregori, Sapena, and Žikić, resp.) in fuzzy metric spaces to intuitionistic fuzzy metric spaces.
The Weighted Gini-Simpson Index: Revitalizing an Old Index of Biodiversity
Authors: Guiasu Radu Cornel , Guiasu Silviu
Published: February 2012

The distribution of biodiversity at multiple sites of a region has been traditionally investigated through the additive partitioning of the regional biodiversity into the average within-site biodiversity and the biodiversity among sites. The standard additive partitioning of diversity requires the use of a measure of diversity, which is a concave function of the relative abundance of species, such as the Gini-Simpson index, for instance. Recently, it was noticed that the widely used Gini-Simpson index does not behave well when the number of species is very large. The objective of this paper is to show that the new weighted Gini-Simpson index preserves the qualities of the classic Gini-Simpson index and behaves very well when the number of species is large. The weights allow us to take into account the abundance of species, the phylogenetic distance between species, and the conservation values of species. This measure may also be generalized to pairs of species and, unlike Rao’s index, this measure proves to be a concave function of the joint distribution of the relative abundance of species, being suitable for use in the additive partitioning of biodiversity. The weighted Gini-Simpson index may be easily transformed for use in the multiplicative partitioning of biodiversity as well.
A Class of Semilocal E‐Preinvex Functions and Its Applications in Nonlinear Programming
Authors: Jiao Hehua , Liu Sanyang , Pai Xinying
Published: February 2012

A kind of generalized convex set, called as local star‐shaped E‐invex set with respect to η, is presented, and some of its important characterizations are derived. Based on this concept, a new class of functions, named as semilocal E‐preinvex functions, which is a generalization of semi‐E‐preinvex functions and semilocal E‐convex functions, is introduced. Simultaneously, some of its basic properties are discussed. Furthermore, as its applications, some optimality conditions and duality results are established for a nonlinear programming.
The Effects of Chemical Reaction, Hall, and Ion‐Slip Currents on MHD Micropolar Fluid Flow with Thermal Diffusivity Using a Novel Numerical Technique
Authors: Motsa S. S. , Shateyi S.
Published: February 2012

The problem of magnetomicropolar fluid flow, heat, and mass transfer with suction through a porous medium is numerically analyzed. The problem was studied under the effects of chemical reaction, Hall, ion‐slip currents, and variable thermal diffusivity. The governing fundamental conservation equations of mass, momentum, angular momentum, energy, and concentration are converted into a system of nonlinear ordinary differential equations by means of similarity transformation. The resulting system of coupled nonlinear ordinary differential equations is the then solved using a fairly new technique known as the successive linearization method together with the Chebyshev collocation method. A parametric study illustrating the influence of the magnetic strength, Hall and ion‐slip currents, Eckert number, chemical reaction and
permeability on the Nusselt and Sherwood numbers, skin friction coefficients, velocities, temperature, and concentration was carried out.
Application of PEI-Modified Magnetic Nanoparticles as Gene Transfer Vector for the Genetic Modification of Animals
Authors: Cui Jinhui , Cui Haixin , Wang Yan , Sun Changjiao , Li Kui , Ren Hongyan , Du Wei
Published: February 2012

To evaluate the performance of the magnetic nanoparticles as gene transfer vector for breeding transgenic animals, we investigated a new approach to deliver green fluorescent protein (GFP) gene to porcine kidney 15 (PK-15) and porcine embryonic fibroblast (PEF) cells using PEI-modified magnetic nanoparticles as gene vector. The morphology of the nanoparticles and nanoparticle/DNA complexes was characterized using scanning electron microscopy. It was found that the surface of the particles becomes coarse and rough with increased average diameter, which implied the effective conjugating between nanoparticles with DNA. The zeta potential of nanoparticle/DNA complexes drops down from +29.4 mV to +23.1 mV comparing with pure nanoparticles. Agarose gel electrophoresis experiments show that DNA plasmids can be protected effectively against degradation of exonuclease and endonuclease. The efficiency of gene delivery was affected by the mass ratio of nanoparticle/DNA and the amount of nanoparticle/DNA complexes. We confirm that the most optimal mass ratio of nanoparticle/DNA is 1  :  1 by conducting a series of experiments. This work provides important experimental basis for the application of the magnetic nanoparticles on gene delivery to porcine somatic cells, which is significant for the achieving of breeding new transgenic cloned pigs by using somatic cell nuclear transfer technique.
Risks to Early Childhood Health and Development in the Postconflict Transition of Northern Uganda
Authors: McElroy Theresa A. , Atim Stella , Larson Charles P. , Armstrong Robert W.
Published: February 2012

Research from numerous fields of science has documented the critical importance of nurturing environments in shaping young children's future health and development. We studied the environments of early childhood (birth to 3 years) during postconflict, postdisplacement transition in northern Uganda. The aim was to better understand perceived needs and risks in order to recommend targeted policy and interventions.Methods. Applied ethnography (interview, focus group discussion, case study, observational methods, document review) in 3 sites over 1 year.Results. Transition was a prolonged and deeply challenging phase for families. Young children were exposed to a myriad of risk factors. Participants recognized risks as potential barriers to positive long-term life outcomes for children and society but circumstances generally rendered them unable to make substantive changes.Conclusions. Support structures were inadequate to protect the health and development of children during the transitional period placing infants and young children at risk. Specific policy and practice guidelines are required that focus on protecting hard-to-reach, vulnerable, children during what can be prolonged and extremely difficult periods of transition.
Existence of Solutions for the Evolution p(x)‐Laplacian Equation Not in Divergence Form
Authors: Liu Changchun , Gao Junchao , Lian Songzhe
Published: February 2012

The existence of weak solutions is studied to the initial Dirichlet problem
of the equation ut = udiv(|∇u|p(x)−2∇u), with inf p(x) > 2. We adopt the method of parabolic regularization. After establishing some necessary uniform estimates on the approximate solutions, we prove the existence of weak solutions.
Implementation of a Differential Geometric Filter for Spacecraft Formation Orbit Estimation
Authors: Goh Shu Ting , Abdelkhalik Ossama , Zekavat Seyed A. (Reza)
Published: February 2012

The differential geometric filter is implemented to estimate the absolute and relative positions of the spacecraft in a formation. The extended Kalman Filter is also implemented as a benchmark for the differential geometric estimation. Only relative positions between the spacecraft are measured. Relative positions are measured using a wireless local positioning system (WLPS) installed in all spacecraft. Two different scenarios are studied: (1) the observations include WLPS measurements only and (2) the observations include WLPS measurements in addition to measurements for the absolute position of one spacecraft made by a radar that takes measurements from the earth’s surface. Results show that the differential geometric estimation has better stability performance and a faster convergence rate compared to the extended Kalman filter.
Mesenchymal Stem Cells as a Potent Cell Source for Bone Regeneration
Authors: Zomorodian Elham , Baghaban Eslaminejad Mohamadreza
Published: February 2012

While small bone defects heal spontaneously, large bone defects need surgical intervention for bone transplantation. Autologous bone grafts are the best and safest strategy for bone repair. An alternative method is to use allogenic bone graft. Both methods have limitations, particularly when bone defects are of a critical size. In these cases, bone constructs created by tissue engineering technologies are of utmost importance. Cells are one main component in the manufacture of bone construct. A few cell types, including embryonic stem cells (ESCs), adult osteoblast, and adult stem cells, can be used for this purpose. Mesenchymal stem cells (MSCs), as adult stem cells, possess characteristics that make them good candidate for bone repair. This paper discusses different aspects of MSCs that render them an appropriate cell type for clinical use to promote bone regeneration.
The Mixed Lineage Leukemia (MLL) Fusion–Associated Gene AF4 Promotes CD133 Transcription
Authors: Mak Anthony B. , Nixon Allison M.L. , Moffat Jason
Published: February 2012

The AC133 epitope has been used as a marker for both normal and cancer stem cells from multiple tissue lineages. To identify transcription factors that regulate CD133 expression, we conducted parallel large-scale RNA interference screens in Caco-2 cancer cells that endogenously express CD133 and in engineered HEK293 cells that express CD133 from a heterologous promoter. The transcription factor AF4 was identified following a comparative analysis between the two screens. We then showed that AF4 is a promoter of CD133 transcription in multiple cancer cell lines. Knockdown of AF4 resulted in a dramatic reduction in CD133 transcript levels. Importantly, a subset of pediatric acute lymphoblastic leukemias (ALL) harbor a fusion oncogene results from a chromosomal translocation that juxtaposes the mixed-lineage leukemia (MLL) gene and the AF4 gene. An investigation of the functional role of CD133 in the MLL-AF4–dependent ALL cells revealed that CD133 was required for leukemia cell survival. Together, our findings show AF4-dependent regulation of CD133 expression, which is required for the growth of ALL cells. CD133 may therefore represent a therapeutic target in a subset of cancers. Cancer Res; 72(8); 1929–34. ©2012 AACR.
The Antitumor Immunity of Ipilimumab: (T-cell) Memories to Last a Lifetime?
Authors: Postow Michael A. , Callahan Margaret K. , Wolchok Jedd D.
Published: February 2012

Ipilimumab has shown an overall survival benefit in 2 randomized phase III studies. A minority of patients achieve long-term disease control, highlighting the potential of this immunotherapeutic approach. In ongoing efforts, investigators are continuing to characterize these patients' unique clinical courses and correlate their responses with underlying mechanisms of antitumor immunity. Clin Cancer Res; 18(7); 1821–3. ©2012 AACR.
Prostate-Specific Antigen Screening for Prostate Cancer in Older Men in the United States of America
Authors: Black Amanda , Berg Christine D.
Published: February 2012

Prostate cancer, like many diseases, is more common in older men. Although an estimated 1 in 7 men will be diagnosed with it, the majority of these men will not die from prostate cancer. The latent nature of this disease, the use of screening with prostate-specific antigen (PSA) testing and the greater risk of dying from causes other than prostate cancer contribute to this disparity. As the US population continues to age, prostate cancer screening and disease management presents an increasingly important public health issue. We discuss the current PSA screening recommendations and practices in the USA and the benefits and harms of screening older populations.
The Qualification of Docetaxel or Erlotinib for Second-Line Therapy Should Be Based on Clinical and Molecular Predictive Factors
Authors: Krawczyk Paweł , Kowalski Dariusz M. , Wojas-Krawczyk Kamila , Mlak Radosław , Jaśkiewicz Piotr , Kucharczyk Tomasz , Winiarczyk Kinga , Krzakowski Maciej , Milanowski Janusz
Published: February 2012

Background: We evaluated the effectiveness of docetaxel or erlotinib in second-line treatment of non-small cell lung cancer (NSCLC) and focused on the impact of predictive factors on the outcome of therapy. Methods: 204 patients with progressive disease after platinum-based therapy were enrolled: 102 received an infusion of 75 mg/m2 of docetaxel and 102 received 150 mg of erlotinib orally. Results: Response rate (RR) was 6.9 and 8.8% for docetaxel and erlotinib, respectively. Progression-free survival (PFS) was 1.2 months for docetaxel and 1.6 months for erlotinib (hazard ratio, HR = 1.2, p = 0.17). Overall survival was 5.5 versus 7 months for docetaxel and erlotinib, respectively (HR = 1.35, p = 0.06). Using Cox regression, we found clinical factors (performance status and weight loss) with predictive values for RR and PFS in second-line-treated patients. Prior radiotherapy, smoking status and EGFR mutation might help to predict outcome of erlotinib treatment and βIII-tubulin mRNA expression that of docetaxel, but histopathological diagnosis did not have any predictive value. Conclusions: Erlotinib and docetaxel show similar efficacy in the treatment of NSCLC. The application of predictive factors may facilitate qualification for second-line treatment with both drugs.
Quantification of the Inhomogeneous Distribution of Topically Applied Substances by Optical Spectroscopy: Definition of a Factor of Inhomogeneity
Authors: Weigmann H.-J. , Schanzer S. , Vergou T. , Antoniou C. , Sterry W. , Lademann J.
Published: February 2012

The inhomogeneous distribution of topically applied substances due to decisive differences in the skin structure (furrows and wrinkles) affects the efficacy of cosmetic products, in particular sunscreens. The combination of tape stripping and optical spectroscopy results in absorption data, which reflect ex vivo the inhomogeneity of the in vivo distribution of topically applied substances. Based on these data, a factor of inhomogeneity is defined describing the individual distribution of formulations on the skin surface of volunteers. Thus, the influence of different skin surface structures and the influence of different formulations on the distribution of the topically applied substances can be determined. Analyzing the inhomogeneity data on 6 volunteers (5 sunscreens per volunteer), it was found that the influence on the distribution of sunscreens caused by the formulation was higher than the inhomogeneity originating from the differences in the skin surface structure of the volunteers. The method is well suited to characterize, for example, sunscreens and antiaging creams in the process of development, as well as for the evaluation of the final products.
Using Landscape Topology to Compare Continuous Metaheuristics: A Framework and Case Study on EDAs and Ridge Structure
Authors: Morgan R. , Gallagher M.
Published: February 2012

In this paper we extend a previously proposed randomized landscape generator in combination with a comparative experimental methodology to study the behavior of continuous metaheuristic optimization algorithms. In particular, we generate two-dimensional landscapes with parameterized, linear ridge structure, and perform pairwise comparisons of algorithms to gain insight into what kind of problems are easy and difficult for one algorithm instance relative to another. We apply this methodology to investigate the specific issue of explicit dependency modeling in simple continuous estimation of distribution algorithms. Experimental results reveal specific examples of landscapes (with certain identifiable features) where dependency modeling is useful, harmful, or has little impact on mean algorithm performance. Heat maps are used to compare algorithm performance over a large number of landscape instances and algorithm trials. Finally, we perform a meta-search in the landscape parameter space to find landscapes which maximize the performance between algorithms. The results are related to some previous intuition about the behavior of these algorithms, but at the same time lead to new insights into the relationship between dependency modeling in EDAs and the structure of the problem landscape. The landscape generator and overall methodology are quite general and extendable and can be used to examine specific features of other algorithms.
Visual Spatial Abilities in Uninhabited Ground Vehicle Task Performance During Teleoperation and Direct Line of Sight
Authors: Long Lindsay O.
Published: February 2012

Two experiments investigated the role of spatial abilities on uninhabited ground vehicle (UGV) performance under two different viewing conditions: direct line of sight and teleoperation. The ability to operate a mobile robot was indexed by task completion time and total number of course collisions. Results showed that participants with higher spatial abilities exhibited superior performance in both direct line of sight and teleoperation. Performance under direct line of sight was correlated with both spatial relations and spatial visualization, whereas performance during teleoperation was only correlated with spatial relations ability. Understanding the roles of spatial abilities under different viewing conditions will aid in the advancement of selection criteria and training paradigms for robot operators.
Cloud Coverage in the Joint OSSE Nature Run
Authors: McCarty Will , Errico Ronald M. , Gelaro Ronald
Published: February 2012

A successful observing system simulation experiment (OSSE) is fundamentally dependent on the simulation of the global observing system used in the experiment. In many applications, a free-running numerical model simulation, called a nature run, is used as the meteorological truth from which the observations are simulated. To accurately and realistically simulate observations from any nature run, the simulated observations must contain realistic cloud effects representative of the meteorological regimes being sampled. This study provides a validation of the clouds in the Joint OSSE nature run generated at ECMWF. Presented is the methodology used to validate the nature run cloud fraction fields with seasonally aggregated combined CloudSat/Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) cloud geometric profile retrievals and the Wisconsin High Resolution Infrared Radiation Sounder (HIRS) cloud climatology. The results show that the Joint OSSE nature run has a correct vertical distribution of clouds but lacks globally in cloud amount compared to the validation data. The differences between the nature run and validation datasets shown in this study should be considered and accounted for in the generation of the global observing system for use in full OSSE studies.
Critical Issues in Designing Mixed Methods Policy Research
Authors: Brannen Julia , Moss Gemma
Published: February 2012

This article argues that policy-related research needs to question the assumption that policy questions can be addressed through the use of research methods that examine the issues through one lens only. It proposes that mixed methods research designs work well when they exploit the potential to see different things, and recognize the limits and the potential that each method offers. In this regard it suggests paying particular attention to team composition, organization, and team work. Drawing on two exemplar studies of policy-related research, the article identifies key ingredients in their mixed methods research designs; the equality of status given to the different research approaches used; the importance of tailoring research questions in relation to their own epistemological and methodological assumptions; the importance of distinguishing between different forms of explanation in the process of comparing and presenting quantitative and qualitative data.
Racial/Ethnic Inequality in Wealth during Young Adulthood and Midlife
Authors: Mossakowski Krysia N.
Published: February 2012

Our knowledge remains limited about why there are large racial/ethnic differences in wealth among the middle class in the United States. Owning a home and having positive net worth (i.e., more assets than debts) are important aspirations for the middle class because they signify wealth. This study uses a social-psychological perspective and data from the National Longitudinal Survey of Youth to explore whether the effects of psychological dispositions on these indicators of wealth differ for Blacks, Hispanics, and Whites. Results reveal that having a stronger sense of personal control over life and higher self-esteem significantly increase the odds of achieving positive net worth and homeownership, independent of demographics, educational attainment, current employment, income, and the socioeconomic status of the family of origin. Moreover, interaction effects indicate that the influence of internal locus of control on wealth is stronger for Whites than Blacks. Overall, this study’s findings suggest that the journey between social origins and destinations does not simply need socioeconomic resources, but also psychological resources that come from within the self-concept of the individual. The public policy and mental health implications for the Black middle class are discussed.
Effect of impactor radius on low-velocity impact damage of glass/epoxy composites
Authors: Whisler Daniel , Kim Hyonny
Published: February 2012

With composites finding increased use as primary structures in commercial aircraft, it is necessary to understand the development of damage when a laminate is subject to low-velocity impacts from a variety of sources, which often occur during normal service operations and routine maintenance. In particular, contact with ground service equipment can present a blunt impact to the composite structure. Therefore, the effects of bluntness of an impactor are of interest as this is related to the development of any internal damage in the laminate, or even the surrounding structure, and also affects the visual detectability of an impact event. The objective of this investigation is to determine the effect of impactor radius on the impact damage resistance of composite panels. A low-velocity pendulum impactor was used to strike 200 mm2 woven glass/epoxy composite plates of 3.18 and 6.35 mm thickness. Hemispherical steel impactor tips of radius 12.7, 50.8, and 152.4 mm were mounted to a piezoelectric force sensor which measures the contacting force history during the impact event. Distinct threshold energy levels defining the onset of delamination and backside fiber breakage have been measured to increase significantly with increasing impactor tip radius due to development of higher contact area.
Buckling and compressive failure of stepped-lap joints repaired with composite patches
Authors: Beylergil Bertan , Aktas Alaattin , Cunedioglu Yusuf
Published: February 2012

In this study, the buckling and compressive failure of adhesively-bonded stepped-lap joints (with/without composite patches) composed of pultruded glass fiber-reinforced polymer composite laminates was investigated experimentally and numerically. Two-component epoxy adhesive was used for bonding purposes. Composite patches were woven glass-epoxy layer. They were added onto the conventional stepped-lap joints so that additional load transfer paths were created and localized stress concentrations near joint edge were reduced. The axial compression tests were performed and the results revealed that the buckling and failure load of new stepped lap composite joints with composite patches were significantly higher than the conventional stepped lap joints. The influence of the overlap length was evaluated. For both types of joints, a small increase was observed in failure loads by increase of the overlap length. Numerical results showed a very good agreement with experimental results.
Improving the structural properties and damage tolerance of bonded composite joints using z-pins
Authors: Koh TM , Isa MD , Chang P , Mouritz AP
Published: February 2012

The effect of z‐pin reinforcement on the structural properties and damage tolerance of composite joints is experimentally studied in this article. The ultimate load, failure strain, and absorbed energy capacity of carbon fiber‐epoxy T‐joints and single lap joints increased rapidly with the volume content of z‐pins. The improvement to these properties was due to the capacity of z‐pins to resist unstable (rapid) delamination growth along the bonded region to the T‐joints (induced by interlaminar mode I stress) and lap joints (induced by interlaminar mode II stress) by forming a crack bridging traction zone. Large increases to the damage tolerance of T‐joints and lap joints containing pre‐existing bond‐line cracks were also achieved by z‐pins. The z‐pins formed a bridging traction zone across the delaminated bond‐line which retained high strength in the joints, even in the presence of very long cracks which severely weakened conventional joints.
Osteogenic Effect of High-frequency Acceleration on Alveolar Bone
Authors: Alikhani M. , Khoo E. , Alyami B. , Raptis M. , Salgueiro J.M. , Oliveira S.M. , Boskey A. , Teixeira C.C.
Published: February 2012

Mechanical stimulation contributes to the health of alveolar bone, but no therapy using the osteogenic effects of these stimuli to increase alveolar bone formation has been developed. We propose that the application of high-frequency acceleration to teeth in the absence of significant loading is osteogenic. Sprague-Dawley rats were divided among control, sham, and experimental groups. The experimental group underwent localized accelerations at different frequencies for 5 min/day on the occlusal surface of the maxillary right first molar at a very low magnitude of loading (4 µε). Sham rats received a similar load in the absence of acceleration or frequency. The alveolar bone of the maxilla was evaluated by microcomputed tomography (µCT), histology, fluorescence microscopy, scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR imaging), and RT-PCR for osteogenic genes. Results demonstrate that application of high-frequency acceleration significantly increased alveolar bone formation. These effects were not restricted to the area of application, and loading could be replaced by frequency and acceleration. These studies propose a simple mechanical therapy that may play a significant role in alveolar bone formation and maintenance.
Motivational Constructs Influencing Undergraduate Students’ Choices to Become Classroom Music Teachers or Music Performers
Authors: Parkes Kelly A. , Jones Brett D.
Published: February 2012

The primary purpose of this study was to examine whether any of the six motivational constructs in the expectancy-value model of motivation (i.e., expectancy, ability perceptions, intrinsic interest value, attainment value, social utility value, and cost) would predict whether students intended to have a career teaching classroom music or performing music. Participants included 270 undergraduate students enrolled in music programs at seven major U.S. universities who completed an online questionnaire. Using stepwise multiple regression, the authors documented that attainment value, intrinsic interest value, and expectancy predicted 74% of the variance in whether students intended to choose a career teaching music. They found that expectancy, attainment value, ability perceptions, and intrinsic interest value explained 65% of the variance in whether students intended to choose a career in music performance. Because of the importance of attainment value in predicting students’ intentions to teach and the importance of expectancies in predicting their intentions to have a performance career, these two constructs would be obvious choices for teachers and advisors to target if they want to encourage students to pursue these careers.
Leisure Politics: The Construction of Social Infrastructure and Flemish Cultural Identity in Belgium, 1950s to 1970s
Authors: Gosseye Janina
Published: February 2012

This article ties the expansion of the (European) welfare state model to Belgian national politics and exemplifies how welfare state concepts, such as universalism and decommodification, were adopted in the political campaign for Flemish nationalism in a country on its path to federalism. It focuses on the construction of leisure infrastructure in Flanders, the northern (Flemish-speaking) region of the country, and scrutinizes the role that planning, urbanism, and architecture played in the political project that was set up to strengthen the Flemish community and craft a sense of Flemish cultural identity. It furthermore relates these developments to the situation of pillarization in the country and explicates the convergence of these different forces by narrating the developments in one (telling) case study municipality (Dilbeek) in the Flemish border of the capital city.
The Rural and Urban at War: Invasion and Reconstruction in China during the Anti-Japanese War of Resistance
Authors: Lincoln Toby
Published: February 2012

This article explores the impact of the Japanese invasion of 1937 on Chinese cities. Focusing on Wuxi, one hundred miles to the west of Shanghai, the author argues that bombing was mainly limited to those commercial and industrial areas of the city that had come to define its modern identity. At the same time, municipal authorities also took steps to prepare the city and its inhabitants for war, although these were largely ineffective. However, the destruction of the invasion actually led to changes in urban morphology as the city was rebuilt in 1938. Meanwhile out in the countryside, some towns and villages remained wholly unaffected by the invasion. This exposes the need for a spatial analysis of how violence affects different areas in the city and countryside.
Moving to Integration? The Origins of Chicago’s Gautreaux Program and the Limits of Voucher-Based Housing Mobility
Authors: Gill Andrea M. K.
Published: February 2012

This article explores the origins and implementation of Chicago’s Gautreaux Assisted Housing Program, which used federal vouchers to move poor African American families to majority-white neighborhoods in the Chicago suburbs between 1976 and 1997. The program grew out of discrimination lawsuits by public housing tenants against the Chicago Housing Authority and Department of Housing and Urban Development. The plaintiffs originally sought the construction of new suburban public housing, but changes in federal policy, including the creation of vouchers, and shifts in civil rights jurisprudence confined them to the use of privately owned, existing housing. As a result, the remedy for state-sponsored segregation sent poor black families into a historically segregated housing market that remained largely unaltered by civil rights legislation. In addition, the program’s use of tenant screening and counseling services transformed the litigation from an attempt to reorganize metropolitan housing markets into a program of uplift and racial pioneering in white neighborhoods. This article underscores the ways in which market-based solutions, and the unspoken resistance to integration they sometimes fostered, are important to understanding not only the fate of the Gautreaux program but also the obstacles to civil rights litigation and suburban integration that emerged in the 1970s and beyond.
The influence of mean arterial blood pressure during cardiopulmonary bypass on postoperative renal dysfunction in elderly patients
Authors: Sirvinskas E , Benetis R , Raliene L , Andrejaitiene J
Published: February 2012

The aim of the study was to find out if there is an optimal mean arterial blood pressure (MABP) during cardiopulmonary bypass (CPB) for renal function in elderly patients during the early postoperative period. We analysed the data of 122 patients >70 years of age with normal preoperative renal function who had been subjected to coronary artery bypass grafting (CABG) procedures on CPB. Patients were divided into 3 groups, according to MABP during CPB: group MP (n=50) included patients whose MABP was maintained between 60–70 mmHg; group LP (n=36), the MABP was <60 mmHg; and group HP (n=36) where the MABP was >70 mmHg. The patients’ clinical data were evaluated during the first three postoperative days. The rate of renal impairment (urine output <50ml/h) in the early postoperative period after cardiac surgery did not differ among the groups. Oliguria developed in 3 patients (6%) of the MP group, in 2 patients (5.6%) in the LP group and in 6 patients (16.7%) in the HP group (χ2=3.6, df=2, p=0.161). Evaluation of MABP on renal excretion showed that there was no difference in urine output among the groups. Serum creatinine levels at the end of the first postoperative day in groups MP, LP and HP were 102.7±20.1, 116.4±58.6 and 113.2±39.8 µmol/L, respectively (F=0.5, df=2, p=0.640). There were no significant differences among the groups at the end of the second and the third day either. Volume balance at the end of surgery and during the early postoperative period was similar in all groups. The need for diuretics did not differ among the groups. The length of postoperative hospital stay was not significantly different among the groups. Our study did not reveal any relationship between a MABP of 48-80 and postoperative renal dysfunction in elderly patients after CABG surgery.