bluuebunny/crossref_metadata_2025 huggingface dataset:
DIELECTRIC PROPERTIES OF Ni2+ AND Mn3+ SUBSTITUTED Li-FERRITE PREPARED BY MICROWAVE SINTERING TECHNIQUE
Authors: MAISNAM MAMATA , PHANJOUBAM SUMITRA , SARMA H. N. K. , RADHAPIYARI DEVI L. , THAKUR O. P. , PRAKASH CHANDRA
Published: April 2007

Li 0.45 Ni 0.1 Mn 0.1 Fe 2.35 O 4 ferrite samples were prepared by microwave-sintering (MS) and conventional (CS) techniques. XRD studies have confirmed the single-phase spinel structure of the sample. The lattice constant was found to be 8.334 Å which is lower than that of the conventionally sintered (CS) sample. Upon microwave sintering, improved physical and electrical properties (like density, resistivity etc.) were obtained. A comparative study has been made on the dielectric behavior of samples processed by both techniques. The possible mechanisms are discussed.
NOVEL METHODS TO IMPROVE PULSE ENERGY OF Q-SWITCHED FIBER LASER
Authors: SHANG LIANJU , NING JIPING , FAN GUOFANG , CHEN ZHIQIANG , HAN QUN , ZHANG HUAYONG
Published: April 2007

Q-switched fiber lasers are very attractive sources in many applications such as in military affairs, surgical operation, laser machining, laser marking, nonlinear frequency conversion, range finding, remote sensing and optical time domain reflectometer. Our goal is to improve the pulse energy of a Q-switched fiber laser. In this paper, certain feasible methods to improve the pulse energy are presented, with their theoretical basis clarified, which may be helpful for the design of kindred Q-switched fiber lasers.
MAGNETIC PHASE DIAGRAMS OF THE GENERALIZED SPIN-ONE-HALF FALICOV–KIMBALL MODEL
Authors: ŽONDA MARTIN
Published: April 2007

A combination of small-cluster exact-diagonalization calculations and a well-controlled approximative method is used to examine the ground-state phase diagrams of the spin-one-half Falicov–Kimball model extended by the spin-dependent on-site interaction (J) between localized spins and itinerant (d) electrons, as well as by external magnetic field (h). Both the magnetic ordering and metamagnetic transitions are analyzed as functions of h and the number of itinerant electrons (Nd) at selected J. Various magnetic superstructures including axial and diagonal spin stripes are observed for non-zero values of J and h. Moreover, it is shown that increasing h strongly stabilizes the fully and partially polarized states, while the non-polarized state is reduced.
HIERARCHICAL SET-ASSOCIATE CACHE FOR HIGH-PERFORMANCE AND LOW-ENERGY ARCHITECTURE
Authors: ZARANDI HAMID R. , MIREMADI SEYED GHASSEM
Published: April 2007

This paper presents a new cache scheme based on varying the size of sets in the set-associative cache hierarchically. In this scheme, all sets at a hierarchical level have same size but are k times more than the size of sets in the next level of hierarchy where k is called division factor. Therefore the size of tag fields associated to each set is variable and it depends on the hierarchy level of the set it is in. This scheme is proposed to achieve higher hit ratios with respect to the two conventional schemes namely set-associative and direct mapping. The proposed scheme has been simulated with several standard trace files SPEC 2000 and statistics are gathered and analyzed for different cache configurations. The results reveal that the proposed scheme exhibits a higher hit ratio compared to the two well-known mapping schemes, namely set-associative and direct mapping. Moreover, the area and power consumption of this scheme is less than full-associative scheme.
ROBUST COLOR OBJECT TRACKING WITH APPLICATION TO PEOPLE MONITORING
Authors: TAO JI , TAN YAP-PENG , LU WENMIAO
Published: April 2007

We present an automated and complete camera-based monitoring system that makes use of low-level color features to perform detection, tracking and recognition of multiple people in video sequence. Specifically, the system employs a novel coverage check-up method to segment detected foreground regions into isolated people and then localize each of them. During tracking, the appearances of people are modeled by their color histograms so that the system can keep aware of their identities and recognize them after occlusions by maximizing the joint likelihood. To make the recognition more robust against shadows or changes of background illumination, the system also incorporates a shadow removal scheme to suppress shadow effects and hence improve the quality of color histogram. The proposed system has been used to identify people who re-enter the field of view of a monitoring camera in a closed-environment. Experimental results of real video data demonstrate the efficacy of the proposed people monitoring system.
LABELLING OF THREE DIMENSIONAL HUMAN BODY SCANS: A TOPOLOGICAL APPROACH
Authors: WERGHI NAOUFEL , XIAO YIJUN , SIEBERT PAUL
Published: April 2007

Whole human body scanners are 3D imaging devices which are capable of capturing a computerized format of whole body shape, thus permitting automatic extraction of the different body measurements. This requires the segmentation of scan data into subsets corresponding to the functional human body parts. Such a task is quite challenging due to the articulated and the deformable aspects of the human body shape. The attempts made so far suffer from various limitations, such as being restricted to standard specific posture and vulnerability to scan data corruption. This paper proposes a general framework that aims towards overcoming these challenges. One of the salient features of this framework is that it can cope with moderate posture variations around the standard posture, in addition of being quite robust against noise, holes and irregular sampling. Experimental results performed on real and synthetic data confirmed the validity, effectiveness and robustness of our framework.
AN AUTONOMOUS DECENTRALIZED MULTI-SERVER FRAMEWORK FOR LARGE SCALE COLLABORATIVE VIRTUAL ENVIRONMENTS
Authors: ZHANG LIANG , LIN QINGPING , GAY ROBERT , HUANG GUANGBIN , NEO NORMAN
Published: April 2007

Collaborative Virtual Environment (CVE) is a promising technology which provides an online shared virtual world to the geographically dispersed people to interact with each other. However, the scalability of existing CVE system is limited due to the constraints in processing power and network speed of each participating host. Large scale CVE (LCVE) that supports a large number of concurrent participants and a large amount of evolving virtual entities is not easy to achieve. In this paper, an autonomous decentralized grid based mobile agent framework for large scale CVE — MACVE is proposed. In MACVE, LCVE software system is decomposed into a group of collaborative mobile agents, each of which is responsible for an independent system task. Agents can migrate or clone dynamically at any suitable participating host (grid node) include traditional servers and qualified user hosts to avoid bottleneck, which can improve the scalability of LCVE. Therefore, MACVE is a logically multi-server architecture while the server workload is autonomously decentralized. Our system prototype and evaluation has demonstrated the feasibility of the proposed framework.
A FAST CODEBOOK DESIGN ALGORITHM BASED ON A FUZZY CLUSTERING METHODOLOGY
Authors: ABDELWAHAB AHMED A. , MUHARRAM NORA S.
Published: April 2007

In this paper, a new fast one-step codebook design algorithm for vector quantization is proposed for image coding. The algorithm utilizes a fuzzy clustering methodology for best clustering of data vectors in the training space. The codebook design process terminates in just one step so that it is highly computationally efficient as compared to other reported algorithms. To improve the coding efficiency, image blocks are further classified into two classes and a different codebook is designed for each class. The two codebooks are augmented to form one codebook so that there is no need to send class information. Moreover, entropy coding is used to send codevector index to the receiver for further bit rate reduction. Simulation results are presented to show the superior performance of the proposed algorithm in terms of PSNR as compared to the state-of-the-art codebook design algorithms.
LOCALIZATION IN COALGEBRAS: APPLICATIONS TO FINITENESS CONDITIONS
Authors: GÓMEZ-TORRECILLAS J. , NĂSTĂSESCU C. , TORRECILLAS B.
Published: April 2007

We introduce the notion of right strictly quasi-finite coalgebras, as coalgebras with the property that the class of quasi-finite right comodules is closed under factor comodules, and study its properties. A major tool in this study is the local techniques, in the sense of abstract localization.
THE pp CONJECTURE FOR SPACES OF ORDERINGS OF RATIONAL CONICS
Authors: GŁADKI PAWEŁ , MARSHALL MURRAY
Published: April 2007

First counterexamples are given to a basic question raised in [10]. The paper considers the space of orderings (X,G) of the function field of a real irreducible conic [Formula: see text] over the field ℚ of rational numbers. It is shown that the pp conjecture fails to hold for such a space of orderings when [Formula: see text] has no rational points. In this case, it is shown that the pp conjecture "almost holds" in the sense that, if a pp formula holds on each finite subspace of (X,G), then it holds on each proper subspace of (X,G). For pp formulas which are product-free and 1-related, the pp conjecture is known to be true, at least if the stability index is finite [11]. The counterexamples constructed here are the simplest sort of pp formulas which are not product-free and 1-related.
COMPUTING THE ADDITIVE STRUCTURE OF INDECOMPOSABLE MODULES OVER DEDEKIND-LIKE RINGS USING GRÖBNER BASES
Authors: AVIÑO-DIAZ MARIA A. , GARCIA-PUENTE LUIS D.
Published: April 2007

We introduce a general constructive method to find a p-basis (and the Ulm invariants) of a finite Abelian p-group M. This algorithm is based on Gröbner bases theory. We apply this method to determine the additive structure of indecomposable modules over the following Dedeking-like rings: ℤCp, where Cp is the cyclic group of order a prime p, and the p-pullback {ℤ → ℤp ← ℤ} of ℤ ⊕ ℤ.
SUBADDITIVE PERIODIC FUNCTIONS AND NUMERICAL SEMIGROUPS
Authors: ROSALES J. C.
Published: April 2007

We study the relationship between numerical semigroups and periodic subadditive functions.
Hypoxic upregulation of glucose transporters in BeWo choriocarcinoma cells is mediated by hypoxia-inducible factor-1
Authors: Baumann Marc U. , Zamudio Stacy , Illsley Nicholas P.
Published: April 2007

Placental hypoxia has been implicated in pregnancy pathologies, including fetal growth restriction and preeclampsia; however, the mechanism by which the trophoblast cell responds to hypoxia has not been adequately explored. Glucose transport, a process crucial to fetoplacental growth, is upregulated by hypoxia in a number of cell types. We investigated the effects of hypoxia on the regulation of trophoblast glucose transporter (GLUT) expression and activity in BeWo choriocarcinoma cells, a trophoblast cell model, and human placental villous tissue explants. GLUT1 expression in BeWo cells was upregulated by the hypoxia-inducing chemical agents desferroxamine and cobalt chloride. Reductions in oxygen tension resulted in dose-dependent increases in GLUT1 and GLUT3 expression. Exposure of cells to hypoxic conditions also resulted in an increase in transepithelial glucose transport. A role for hypoxia-inducible factor (HIF)-1 was suggested by the increase in HIF-1α as a result of hypoxia and by the increase in GLUT1 expression following treatment of BeWo with MG-132, a proteasomal inhibitor that increases HIF-1 levels. The function of HIF-1 was confirmed in experiments where the hypoxic upregulation of GLUT1 and GLUT3 was inhibited by antisense HIF-1α. In contrast to BeWo cells, hypoxia produced minimal increases in GLUT1 expression in explants; however, treatment with MG-132 did upregulate syncytial basal membrane GLUT1. Our results show that GLUTs are upregulated by hypoxia via a HIF-1-mediated pathway in trophoblast cells and suggest that the GLUT response to hypoxia in vivo will be determined not only by low oxygen tension but also by other factors that modulate HIF-1 levels.
Changes in environmental temperature influence leptin responsiveness in low- and high-fat-fed mice
Authors: Harris Ruth B. S. , Mitchell Tiffany D. , Kelso Emily W. , Flatt W. P.
Published: April 2007

Loss of body fat in leptin-treated animals has been attributed to reduced energy intake, increased thermogenesis, and preferential fatty acid oxidation. Leptin does not decrease food intake or body fat in leptin-resistant high-fat (HF)-fed mice, possibly due to a failure of leptin to activate hypothalamic receptors. We measured energy expenditure of male C57BL/6 mice adapted to low-fat (LF) or HF diet and infused them for 13 days with PBS or 10 μg leptin/day from an intraperitoneal miniosmotic pump to test whether leptin resistance prevented leptin-induced increases in energy expenditure and fatty acid oxidation. There was no effect of low-dose leptin infusions on either of these measures in LF-fed or HF-fed mice, even though LF-fed mice lost body fat. Experiment 2 tested leptin responsiveness in LF-fed and HF-fed mice housed at different temperatures (18°C, 23°C, 27°C), assuming that the cold would increase and the hot environment would inhibit food intake and thermogenesis, which could potentially interfere with leptin action. LF-fed mice housed at 23°C were the only mice that lost body fat during leptin infusion, suggesting that an ability to modify energy expenditure is essential to the maintenance of leptin responsiveness. HF-fed mice in cold or warm environments did not respond to leptin. HF-fed mice in the hot environment were fatter than other HF-fed mice, and, surprisingly, leptin caused a further increase in body fat, demonstrating that the mice were not totally leptin resistant and that partial leptin resistance in a hot environment favors positive energy balance and fat deposition.
Angiotensin AT1-receptor inhibition exacerbates renal injury resulting from partial unilateral ureteral obstruction in the neonatal rat
Authors: Coleman Christopher M. , Minor Jordan J. , Burt Laura E. , Thornhill Barbara A. , Forbes Michael S. , Chevalier Robert L.
Published: April 2007

The renin-angiotensin system is activated in the developing kidney and is necessary for normal renal development, but is further activated by unilateral ureteral obstruction (UUO). During nephrogenesis, there is a switch from a preponderance of angiotensin AT2to AT1receptors in the rat. We examined the renal cellular response to angiotensin II receptor inhibition in the neonatal rat subjected to partial UUO under anesthesia within 48 h of birth. Group I (“early”) received saline vehicle, losartan (AT1inhibitor), or PD-123319 (AT2inhibitor) during the completion of nephrogenesis in the first 10 days of life. Group II (“late”) received each of the three treatments throughout the subsequent 10 days of life. Kidneys were harvested at 21 days, and the distribution of renin, apoptosis, macrophages, α-smooth muscle actin, and collagen was determined. Losartan and PD-123319 each increased vascular renin distribution in both kidneys. Partial UUO reduced growth and increased apoptosis, macrophages, α-smooth muscle actin, and collagen in the obstructed kidney. Early losartan treatment further increased α-smooth muscle actin and collagen in the obstructed kidney and induced apoptosis, macrophages, and collagen in the contralateral kidney. Late losartan treatment had no effect on any of the parameters in either kidney, and PD-123319 had no effect on either kidney. We conclude that selective inhibition of AT1receptors during nephrogenesis (but not during subsequent renal maturation) exacerbates injury to the obstructed kidney and also injures the contralateral kidney. These results suggest that angiotensin II receptor blockers should be avoided in the developing hydronephrotic kidney.
Presynaptic Inhibition of Excitatory Afferents to Hilar Mossy Cells
Authors: Nahir Ben , Bhatia Chinki , Frazier Charles J.
Published: April 2007

The hippocampus contains one very strong recurrent excitatory network formed by associational connections between CA3 pyramidal cells and another that depends largely on a disynaptic excitatory pathway between dentate granule cells. The recurrent excitatory network in CA3 has long been considered a possible location of autoassociative memory storage, whereas changes in the level and arrangement of recurrent excitation between granule cells are strongly implicated in epileptogenesis. Hilar mossy cells are likely to receive collateral input from CA3 pyramidal cells and they are key intermediaries (by mossy fiber inputs) in the recurrent excitatory network between granule cells. The current study uses minimal stimulation techniques in an in vitro preparation of the rat dentate gyrus to examine presynaptic modulation of both mossy fiber and non-mossy fiber inputs to hilar mossy cells. We report that both mossy fiber and non-mossy fiber inputs to hilar mossy cells express presynaptic γ-aminobutyric acid type B (GABAB) receptors that are subject to tonic inhibition by ambient GABA. We further find that only non-mossy fiber inputs express presynaptic muscarinic acetylcholine receptors, but that bath application of cholinergic agonists produces action potential–dependent increases in ambient GABA that can indirectly inhibit mossy fiber inputs. Finally, we demonstrate that mossy cells express high-affinity postsynaptic GABAA receptors that are also capable of detecting changes in ambient GABA produced by cholinergic agonists. Our results are among the first to directly characterize these important collateral inputs to hilar mossy cells and may help facilitate informed comparison between primary and collateral projections in two major excitatory pathways.
A Neural Model of Figure–Ground Organization
Authors: Craft Edward , Schütze Hartmut , Niebur Ernst , von der Heydt Rüdiger
Published: April 2007

Psychophysical studies suggest that figure–ground organization is a largely autonomous process that guides—and thus precedes—allocation of attention and object recognition. The discovery of border-ownership representation in single neurons of early visual cortex has confirmed this view. Recent theoretical studies have demonstrated that border-ownership assignment can be modeled as a process of self-organization by lateral interactions within V2 cortex. However, the mechanism proposed relies on propagation of signals through horizontal fibers, which would result in increasing delays of the border-ownership signal with increasing size of the visual stimulus, in contradiction with experimental findings. It also remains unclear how the resulting border-ownership representation would interact with attention mechanisms to guide further processing. Here we present a model of border-ownership coding based on dedicated neural circuits for contour grouping that produce border-ownership assignment and also provide handles for mechanisms of selective attention. The results are consistent with neurophysiological and psychophysical findings. The model makes predictions about the hypothetical grouping circuits and the role of feedback between cortical areas.
Development of Cholinergic Modulation and Graded Persistent Activity in Layer V of Medial Entorhinal Cortex
Authors: Reboreda Antonio , Raouf Ramin , Alonso Angel , Séguéla Philippe
Published: April 2007

During muscarinic modulation, principal neurons from layer V of rat medial entorhinal cortex (mEC) respond to repeated applications of a brief stimulus with a graded change in persistent firing frequency. This pattern of discharge has been proposed to represent an intrinsic mechanism for short-term memory operations. To investigate the implementation of persistent activity in mEC during development, we characterized the electrophysiological properties of layer V principal neurons in the mEC over a range of postnatal stages. We observed significant differences in both passive (resistance, time constant, and resting membrane potential) and active properties (threshold, action potential, and adaptation) of principal neurons from rats aged 5–7, 10–13, 16–19, and 21–23 days. We also examined the properties of muscarinic-dependent persistent activity in EC slices from different age groups. Recordings were conducted using the perforated-patch whole cell technique because persistent activity runs down in the ruptured-patch configuration. Although no neuron in the youngest group exhibited graded persistent activity in response to muscarinic receptor activation, this activity was recorded in the 10- to 13-day-old group and its occurrence increased from 69% in the 16- to 19-day-old group to 76% in the 21- to 23-day-old group. This postnatal increase in neurons endowed with persistent firing properties in mEC was found to parallel the increase in density of ChAT-positive immunostaining of fibers and the developmental changes in M1 muscarinic receptor mRNA levels. All these data suggest that the implementation of mnemonic properties in mEC principal neurons matches the ontogenic development of afferent cholinergic circuits and their signaling components.
Reinforcement Learning Through Modulation of Spike-Timing-Dependent Synaptic Plasticity
Authors: Florian Răzvan V.
Published: April 2007

The persistent modification of synaptic efficacy as a function of the relative timing of pre- and postsynaptic spikes is a phenomenon known as spike-timing-dependent plasticity (STDP). Here we show that the modulation of STDP by a global reward signal leads to reinforcement learning. We first derive analytically learning rules involving reward-modulated spike-timing-dependent synaptic and intrinsic plasticity, by applying a reinforcement learning algorithm to the stochastic spike response model of spiking neurons. These rules have several features common to plasticity mechanisms experimentally found in the brain. We then demonstrate in simulations of networks of integrate-and-fire neurons the efficacy of two simple learning rules involving modulated STDP. One rule is a direct extension of the standard STDP model (modulated STDP), and the other one involves an eligibility trace stored at each synapse that keeps a decaying memory of the relationships between the recent pairs of pre- and postsynaptic spike pairs (modulated STDP with eligibility trace). This latter rule permits learning even if the reward signal is delayed. The proposed rules are able to solve the XOR problem with both rate coded and temporally coded input and to learn a target output firing-rate pattern. These learning rules are biologically plausible, may be used for training generic artificial spiking neural networks, regardless of the neural model used, and suggest the experimental investigation in animals of the existence of reward-modulated STDP.
A Measurement Fusion Method for Nonlinear System Identification Using a Cooperative Learning Algorithm
Authors: Xia Youshen , Kamel Mohamed S.
Published: April 2007

Identification of a general nonlinear noisy system viewed as an estimation of a predictor function is studied in this article. A measurement fusion method for the predictor function estimate is proposed. In the proposed scheme, observed data are first fused by using an optimal fusion technique, and then the optimal fused data are incorporated in a nonlinear function estimator based on a robust least squares support vector machine (LS-SVM). A cooperative learning algorithm is proposed to implement the proposed measurement fusion method. Compared with related identification methods, the proposed method can minimize both the approximation error and the noise error. The performance analysis shows that the proposed optimal measurement fusion function estimate has a smaller mean square error than the LS-SVM function estimate. Moreover, the proposed cooperative learning algorithm can converge globally to the optimal measurement fusion function estimate. Finally, the proposed measurement fusion method is applied to ARMA signal and spatial temporal signal modeling. Experimental results show that the proposed measurement fusion method can provide a more accurate model.
Le cycle de Gédéon ou la condamnation du refus de la royauté
Authors: de Castelbajac Isabelle
Published: April 2007

Far from exemplifying the anti-monarchist position of the Deuteronomistic author, Gideon's cycle underlines his impiety, which, unlike in the case of Abimelek, shows itself not through his thirst for leadership, but through his refusal to carry out the functions assigned by Yahweh. The portrait of a Gideon, as a Canaanite leader, contrasts with the proto-royal portrait of the Israelite Gideon, who is both a war leader and champions Yahweh's cult. The Canaanite figure not only rejects the signs of his divine appointment, whether they show themselves in the divine call or through military victories, but also is responsible for the institution of an idolatrous cult. The Deuteronomistic author thus resets distinct bodies of old traditions, establishing a close link between Gideon-Yerubaal and Abimelek. But the writing of Abimelek's cycle seems to be older than Gideon's one.
Effectively Communicating Qualitative Research
Authors: Ponterotto Joseph G. , Grieger Ingrid
Published: April 2007

This article is a guide for counseling researchers wishing to communicate the methods and results of their qualitative research to varied audiences. The authors posit that the first step in effectively communicating qualitative research is the development of strong qualitative research skills. To this end, the authors review a process model for developing such competence and emphasize the importance of research paradigm and philosophy-of-science knowledge for the competent researcher. The authors present characteristics of strong qualitative writing and highlight the concept of “thick description.” The article includes a recommended structure for presenting the qualitative study and provides suggestions for targeting writing for different audiences. The authors conclude with suggestions for graduate students considering conducting qualitative dissertations.
Teaching Qualitative Research
Authors: Poulin Karen L.
Published: April 2007

Qualitative research has become increasingly perceived as well suited to the advancement of counseling psychology, yet opportunities for formal training in qualitative inquiry remain inconsistently available within and across graduate programs. For the potential contribution of this approach to counseling psychology to be realized, graduate students need routine access to adequate and appropriate coursework. In this article, the author shares a design and rationale for an introductory course in qualitative research, describes typical challenges faced by students, and offers strategies for fostering student learning and success. Limitations of the approach are discussed and recommendations offered based on lessons learned from practice.
Moderating and Mediating Effects of Gender and Psychological Disengagement on the Academic Achievement of African American College Students
Authors: Cokley Kevin , Moore Paula
Published: April 2007

The major purposes of the present study were (a) to examine the degree to which gender moderates the relationship between ethnic identity and academic achievement and (b) to examine whether psychological disengagement (i.e., devaluing academic success [DAS]) mediates gender differences in the academic achievement of African American college students. Data from 274 participants (79% female) were examined using measures of psychological disengagement, academic self-concept, ethnic identity, racial centrality, and self-reported grade point average. The results indicated that ethnic identity and racial centrality were negatively related to academic achievement for male students and positively related to academic achievement and academic self-concept for female students. Gender differences in DAS explained differences in academic achievement. Implications for future research are discussed.
Gender Differences in African American Adolescents' Personal, Educational, and Occupational Expectations and Perceptions of Neighborhood Quality
Authors: Mello Zena R. , Swanson Dena P.
Published: April 2007

This study was conducted in an effort to generate information toward fostering academic outcomes among African American adolescents. Gender differences in African American adolescents' personal, educational, and occupational expectations were examined in relation to perceptions of neighborhood quality. Participants included 352 African American adolescents residing in an urban area. Measures were self-reported expectations and perceptions of neighborhood quality. Regression analyses indicated that (a) expectations were positively associated with perceptions of neighborhood quality, (b) female adolescents reported more positive expectations than male adolescents, and (c) the association between expectations and perceptions of neighborhood quality depended on gender, with male adolescents who rated their neighborhood higher in quality reporting higher personal and educational expectations than male adolescents who rated their neighborhood poorer in quality. Implications of this study for programs and research that focus on academic outcomes and neighborhoods of African American adolescents are discussed.
Black Milwaukee and the Ghetto Synthesis
Authors: Biles Roger
Published: April 2007

This article briefly examines Joe W. Trotter's Black Milwaukee: The Making of an Industrial Proletariat, 1915-45 twenty years after its publication and notes its significance for urban history. Particularly important was the book's challenge to the “ghetto synthesis,” an influential analysis of the African American experience in U.S. cities, instead of which Trotter proposed a proletarianization model. In the wake of Trotter's critique of the ghetto synthesis, studies of American cities have arrogated greater agency to African Americans.
Nighttime Street Fighting and the Meaning of Place
Authors: Laitinen Rtta
Published: April 2007

The limits of honor and dishonor, order and disorder, and theirs and ours were negotiated in the early modern nighttime streets. These cultural negotiations are approached here from the viewpoint of one particular street fight in the seventeenth-century town of Turku in the province of Finland, in the kingdom of Sweden. The drunken, out-of-control fight included both ritualistic forms of a masculine street fight and uncontrolled rage as well as a territorial contest over urban space. The material form of the street as well as the time of the day added their own influences. The nighttime street emerges as a place of metaphorical and physical boundaries, where open and closed, shared and private, and controlled and suppressed were defined. The aim of the article is to see urban space as something more than just a neutral site of actions and practices or a mere network of social interactions without clear material referents.
Using Sociotransformative Constructivism to Create Multicultural and Gender-Inclusive Classrooms
Authors: Zozakiewicz Cathy , Rodriguez Alberto J.
Published: April 2007

Maxima was an intervention project that focused on assisting teachers to establish more inquiry-based, gender-inclusive, and culturally relevant learning environments. The authors grounded the project by using sociotransformative constructivism as a theoretical framework to steer the implementation of three guiding concepts for professional development. These guiding concepts are as follows: being responsive and theoretically explicit, providing ongoing and on-site support, and reflexive approaches to collaboration. The analysis of multiple data sets gathered during Year 1 of the project indicates that most of the teachers responded positively to the proposed guiding concepts and significantly changed their teaching practice.
Unique and Combined Contributions of Multiple Child Abuse Types and Abuse Severity to Adult Trauma Symptomatology
Authors: Clemmons John C. , Walsh Kate , DiLillo David , Messman-Moore Terri L.
Published: April 2007

Studies have documented the co-occurrence and cumulative impact of multiple types of child maltreatment on later psychosocial difficulties. Other research suggests that child abuse characteristics indicative of severity may also increase risk of later adjustment problems. However, little effort has been made to examine the co-occurrence of both multiple types of maltreatment and abuse severity within a single study. The present investigation examines self-reported child maltreatment and adult functioning in a geographically diverse sample of 1,396 undergraduate students. Results indicate that experiencing multiple types of maltreatment is positively associated with more severe abuse. Although increased maltreatment types and more severe abuse are each associated with greater trauma symptomatology, abuse severity is the stronger of the two predictors. Finally, number of maltreatment types and severity of maltreatment interact to predict greater levels of trauma symptomatology. These results highlight the importance of considering both co-occurring abuse types and severity in research and clinical work with adult victims.
The Impact of Parental Alcohol or Drug Removals on Foster Care Placement Experiences: A Matched Comparison Group Study
Authors: Vanderploeg Jeffrey J. , Connell Christian M. , Caron Colleen , Saunders Leon , Katz Karol H. , Kraemer Tebes Jacob
Published: April 2007

Research has established the coincidence of parental alcohol and other drug (AOD) use and child maltreatment, but few studies have examined the placement experiences and outcomes of children removed because of parental AOD use. The present study examines demographic characteristics and placement experiences of children removed from their homes because of parental AOD use (n = 1,333), first in comparison to the remaining sample of children in foster care (n = 4,554), then in comparison to a matched comparison group of children in foster care who were removed for other reasons (n = 1,333). Relative to the comparison sample, children removed for parental AOD use are less likely to experience co-occurring removal because of neglect and physical or sexual abuse and are more likely to be placed in relative foster care. In addition, these children remain in care longer, experience similar rates of reunification, and have significantly higher rates of adoption.
Exploring the Spatial Dynamics of Alcohol Outlets and Child Protective Services Referrals, Substantiations, and Foster Care Entries
Authors: Freisthler Bridget , Gruenewald Paul J. , Remer Lillian G. , Lery Bridgette , Needell Barbara
Published: April 2007

Controlling for neighborhood demographic characteristics, this study examined the relationship of alcohol outlets with rates of Child Protective Services (CPS) referrals, substantiations, and foster care entries from 1998-2003 in 579 zip codes in California. Data for this panel study were analyzed using spatial random effects panel models. Zip codes with higher concentrations of off-premise alcohol outlets (e.g., convenience or liquor stores) and proportions of Black residents had higher rates of maltreatment. Higher average household size and median household income were generally related to lower child maltreatment rates. More specifically, the model derived estimates that an average decrease of one off-premise outlet per zip code would reduce total referrals to CPS in the 579 zip codes by 1,040 cases, substantiations by 180 cases, and foster care entries by 93 cases. Characteristics of adjacent zip codes also were related to maltreatment rates in local neighborhoods, indicating a spatial dynamic to this relationship. Reductions in number of alcohol outlets per zip code, particularly off-premise outlets, may result in lower rates of child maltreatment.
Child Maltreatment and Foster Care: Unpacking the Effects of Prenatal and Postnatal Parental Substance Use
Authors: Smith Dana K. , Johnson Amber B. , Pears Katherine C. , Fisher Philip A. , DeGarmo David S.
Published: April 2007

Parental substance use is a well-documented risk for children. However, little is known about specific effects of prenatal and postnatal substance use on child maltreatment and foster care placement transitions. In this study, the authors unpacked unique effects of (a) prenatal and postnatal parental alcohol and drug use and (b) maternal and paternal substance use as predictors of child maltreatment and foster care placement transitions in a sample of 117 maltreated foster care children. Models were tested with structural equation path modeling. Results indicated that prenatal maternal alcohol use predicted child maltreatment and that combined prenatal maternal alcohol and drug use predicted foster care placement transitions. Prenatal maternal alcohol and drug use also predicted postnatal paternal alcohol and drug use, which in turn predicted foster care placement transitions. Findings highlight the potential integrative role that maternal and paternal substance use has on the risk for child maltreatment and foster care placement transitions.
Fighting for Control
Authors: Martin Leslie
Published: April 2007

The loss of political influence is an important adverse consequence of gentrification for long-time residents. This study examines why neighborhood organizations in three gentrifying neighborhoods in Atlanta, Georgia, chose to address this potential problem, while organizations in another gentrifying community did not. Organizations of long-time residents, whether formed before gentrification or in response to it, were more likely to address political displacement. Neighborhood organizations with strong track records of providing benefits for neighbors and that adopted accepted organizational forms were more likely to mobilize effectively to protect the political participation of long-time residents. Interorganizational conflict minimized groups' ability to address political changes.
Rethinking the Dual City
Authors: Reichl Alexander J.
Published: April 2007

This article examines social polarization in New York City: first, as an objective condition among city neighborhoods; and second, as an issue in city politics. Data on income, poverty, housing, and crime provide little evidence of growing polarization between low- and high-income neighborhoods in the 1990s. However, the data reveal a striking contrast between the spectacular gains of core areas and the widespread stagnation and decline across low-, middle-, and high-income neighborhoods outside the core. Polarization has not proved a viable political issue because it becomes subsumed in racial/ethnic politics; yet the data suggest that progressives might prevail with a dual-city discourse that highlights the significance of polarization for neighborhoods outside the core.
The International Diffusion of Planning Ideas: The Case of Istanbul, Turkey
Authors: Ayataç Hatice
Published: April 2007

Diffusion is the process by which economical, political, and cultural experiences are shared amongst countries. The international diffusion of planning ideas is defined as borrowing and imposition at national and local levels. In the case of Turkey, these experiences are viewed within the context of modernization and westernization. The most significant arena of this process took place in Istanbul. The process of adaptation began in the second half of the nineteenth century with the Tanzimat reforms and developed parallel to the degree of influence the United States and Europe had on the changes in the political regime and identity of the country in the wake of the two world wars. The financial support of the United States and World Bank investments sped up this process. A European Union harmonization process is now under way. The objective of this study is to relate the Turkish experience of international diffusion of planning ideas and evaluate the contribution of Istanbul's spatial formation.
The Evolution of Early Phoenix: Valley Business Elite, Land Speculation, and the Emergence of Planning
Authors: Larsen Larissa , Alameddin David
Published: April 2007

Phoenix's evolution into one of the dominant metropolitan centers of the American Southwest was the combination of early federal policies, local initiatives, and, most important, the actions of several key business figures. Between 1885 and 1920, W. J. Murphy, Moses Sherman, Dwight Heard, and Benjamin Fowler used their connections to outside investors and federal politicians to advance the small city's promise and to individually profit from its growth. Political initiatives, such as establishing a reform-style government, commissioning a “City Beautiful” plan, and creating a plan commission, were outcomes of the city's early development that flowed directly from the actions of several business leaders. The case of Phoenix underscores how planning reflected the interests of a narrow segment of the political and economic interests of the city.
The Compact versus the Dispersed City: History of Planning Ideas on Sofia's Urban Form
Authors: Hirt Sonia
Published: April 2007

This article reviews the planning history of Sofia since its designation as the Bulgarian capital in 1879. It argues that Sofia's planning has been persistently shaped by two perennial dilemmas—how to reconnect the city with nature and how to define its relationship with the region. In response to these dilemmas, different visions, shaped by both local conditions and dominant foreign theories, were proposed at different times. Some promoted a compact city, while others advocated a dispersed form. The case of Sofia demonstrates the significance of the city-nature and the city-region relationships in the evolution of planning thought. It also points to the difficulties that arise when local ideas of how to organize these relationships are inspired by international models made for cities with different historic experiences.
Anti-CD44-mediated blockade of leukocyte migration in skin-associated immune diseases
Authors: Zöller Margot , Gupta Pooja , Marhaba Rachid , Vitacolonna Mario , Freyschmidt-Paul Pia
Published: April 2007

CD44 plays an important role in leukocyte extravasation, which is fortified in autoimmune diseases and delayed-type hypersensitivity (DTH) reactions. There is additional evidence that distinct CD44 isoforms interfere with the extravasation of selective leukocyte subsets. We wanted to explore this question in alopecia areata (AA), a hair-follicle centric autoimmune disease, and in a chronic eczema. The question became of interest because AA is treated efficiently by topical application of a contact sensitizer, such that a mild DTH reaction is maintained persistently. Aiming to support the therapeutic efficacy of a chronic eczema in AA by anti-CD44 treatment, it became essential to control whether a blockade of migration, preferentially of AA effector cells, could be achieved by CD44 isoform-specific antibodies. Anti-panCD44 and anti-CD44 variant 10 isoform (CD44v10) inhibited in vitro migration of leukocytes from untreated and allergen-treated, control and AA mice. In vivo, both antibodies interfered with T cell and monocyte extravasation into the skin; only anti-panCD44 prevented T cell homing into lymph nodes. Contributing factors are disease-dependent alterations in chemokine/chemokine receptor expression and a blockade of CD44 on endothelial cells and leukocytes. It is important that CD44 can associate with several integrins and ICAM-1. Associations depend on CD44 activation and vary with CD44 isoforms and leukocyte subpopulations. CD44 standard isoform preferentially associates with CD49d in T cells and CD44v10 with CD11b in monocytes. Accordingly, anti-panCD44 and anti-CD49d inhibit T cell, anti-CD11b, and anti-CD44v10 macrophage migration most efficiently. Thus, allergen treatment of AA likely can be supported by targeting AA T cells selectively via a panCD44-CD49d-bispecific antibody.
Caspase-1 inflammasomes in infection and inflammation
Authors: Lamkanfi Mohamed , Kanneganti Thirumala-Devi , Franchi Luigi , Núñez Gabriel
Published: April 2007

Nucleotide-binding and oligomerization domain-like receptors (NLRs) constitute a family of germline-encoded pattern-recognition receptors, which allow the host to respond rapidly to a wide variety of pathogenic microorganisms. Here, we discuss recent advances in the study of a subset of NLRs, which control the activation of caspase-1 through the assembly of large protein complexes, inflammasomes. The NALP1b inflammasome recognizes anthrax lethal toxin, and flagellin from Salmonella and Legionella induces assembly of the Ipaf inflammasome. Cryopyrin/NALP3 mediates caspase-1 activation in response to a wide variety of bacterial ligands, imidazoquinolines, dsRNA, and the endogenous danger signal uric acid. The importance of these cytosolic receptors in immune regulation is underscored by the identification of mutations in cryopyrin/NALP3, which are genetically linked to human autoinflammatory disorders.
Na+/Ca2+ Exchange and Ca2+ Homeostasis in Axon Terminals of Mammalian Central Neurons
Authors: LEE SUK‐HO , KIM MYOUNG‐HWAN , LEE JU‐YOUNG , LEE SANG HUN , LEE DOYUN , PARK KYEONG HAN , HO WON‐KYUNG
Published: April 2007

Abstract:  We investigated Ca2+ clearance mechanisms (CCMs) at the axon terminals of mammalian central neurons: neurohypophysial (NHP) axon terminals and calyces of Held. Ca2+ transients were evoked by applying a short depolarization pulse via a patch pipette containing Ca2+ indicator dye. Quantitative analysis of the Ca2+ decay phases revealed that Na+/Ca2+ exchange (Na/CaX) is a major CCM at both axon terminals. In contrast, no Na/CaX activity was found in the somata of NHP axon terminals (supraoptic magnocellular neurons), indicating that the distribution of Na+/Ca2+ exchangers is polarized. Intracellular dialysis of axon terminals with a K+‐free pipette solution attenuated the Na/CaX activities by 90% in the NHP axon terminals and by 60% at the calyx of Held, indicating that K+‐dependent Na+/Ca2+ exchangers are involved. Studying the effects of specific inhibitors of smooth endoplasmic reticulum Ca2+‐ATPase (SERCA) and plasma membrane Ca2+‐ATPase (PMCA) on the Ca2+ decay rate revealed that PMCA contributed 23% of total Ca2+ clearance, but that SERCA made no contribution at the calyx of Held. The contribution of mitochondria was negligible for small Ca2+ transients, but became apparent at peak Ca2+ levels higher than 2.5 μM. When mitochondrial function was inhibited, the dependence of CCMs on [Ca2+]i at the calyx of Held showed saturation kinetics with K1/2= 1.7 μM, suggesting that the Na/CaX activity is saturated at high [Ca2+]i. The presynaptic Na+/Ca2+ exchanger activity, which competes for cytosolic Ca2+ with mitochondria, may contribute to nonplastic synaptic transmission at these axon terminals.
Sodium–Calcium Exchanger in Pulmonary Artery Smooth Muscle Cells
Authors: ZHENG YUN‐MIN , WANG YONG‐XIAO
Published: April 2007

Abstract:  The expression and function of the Na+/Ca2+ exchanger (NCX) in the regulation of intracellular Ca2+ homeostasis have been well studied in cardiac, skeletal, and systemic vascular myocytes, but not in pulmonary artery smooth muscle cells (SMCs). We have recently demonstrated that the NCX current is present in freshly isolated pulmonary artery SMCs using the patch‐clamp technique. The current has a mean amplitude of 13 pA under near physiological resting conditions. The NCX may function in the forward mode to make a significant contribution to the decay of intracellular Ca2+ following Ca2+ release and/or depolarization. Hypoxic stimulation inhibits the NCX current, reduces the removal of intracellular Ca2+, and enhances Ca2+ release from the sarcoplsamic reticulum. Using RT‐PCR, subcloning and sequence analysis, we have shown that three NCX1 splice variants: NCX1.2 (containing exons B, C, and D), NCX1.3 (exons B and D), and NCX1.7 (exons B, D, and F) are expressed in pulmonary artery smooth muscle. Each of these splice variants expressed in HEK293 cells it likely to show a distinct activity in the removal of intracellular Ca2+. Taken together, we provide clear evidence that NCX1 is functionally and molecularly expressed and plays a physiological role in pulmonary artery SMCs.