bluuebunny/crossref_metadata_2025 huggingface dataset:
Documenting Tragedy and Resilience
Authors: Foster Kevin Michael , Blakes Tifani , McKay Jenny
Published: April 2008

Spike Lee's documentary, When the Levees Broke, provides an informative, enduring, and alternative presentation surrounding the human and man-made debacle associated with Hurricane Katrina. Levees centers the voices of survivors and others involved in the weeks during and after the hurricane, historicizes residents' understandings and reactions, and grounds the entire film in powerful images and footage captured by countless people during the protracted moment. As an enduring document that exists outside of the contemporary television-driven news cycle, Levees provides critical groundwork for community conversation. Likewise, and with thoughtful preparation work, Levees offers a tremendous opportunity for culturally and contextually resonant and relevant classroom teaching.
Academic Identity Development Through Self-Determination
Authors: Anctil Tina M. , Ishikawa Michele E. , Tao Scott Amy
Published: April 2008

This study provides a model of academic identity development for college students with learning disabilities from the integrative self-determination themes of persistence, competence, career decision making, and self-realization. Nineteen self-determined and high-achieving participants were interviewed. The participants' stories illustrate how persistence influences competence, which in turn influences career decision making and ultimately enhances self-realization and supports one's academic identity. Knowledge of one's learning disability, along with self-advocacy and conflict resolution skills, improved the students' ability to obtain academic accommodations in college settings. Secondary education implications include the importance of providing opportunities for students to (a) acquire self-knowledge about their disability, (b) autonomously practice self-advocacy with teachers, and (c) develop conflict resolution skills within the context of academic accommodation requests.
Young People, Hope, and Childhood-Hope
Authors: Kraftl Peter
Published: April 2008

This article outlines a number of steps toward a more sensitive and affirmative conception of childhood and hope (“childhood-hope”). Throughout the article, the author explores how our understandings of hope might be extended via an examination of childhood-hope. First, it considers childhood as a universalizing, affective condition, which can be characterized by very simplistic, and problematic, notions of hope, logic, and futurity. The author connects this line of thought explicitly with what the author identifies as impulses of hopefulness and of “doing good” for children, exemplified by a selection of “high-profile” quotations about children. Second, the author extends the discussion to explore everyday articulations of hope by young people involved in a project concerning their interpretations and experiences of self-esteem. The author concludes by outlining how universal representations of childhood-hope may be extended and critiqued though young people's own articulations of hope, and draw attention to some of the positive political interventions that young people's modest forms of hoping might have.
Experiencing Imminent Justice
Authors: Lashaw Amanda
Published: April 2008

Recent scholarship on the affective dimensions of social change has pointed toward hope as an ethically promising form of belonging. In this article, the articulation of hope in the context of a reform-oriented social movement provides the basis for interrogating the political promise of hope. The author examines the ascent of a movement for small, equitable schools in Oakland, California, to explore the hopes and aspirations of its most ardent advocates. To do this, the author contrasts the movement's assertion of its equity-centered strategy with the complex race and class hierarchies that grounded power relations within the movement. The question that emerges from this discontinuity is how reformers come to experience the movement as equitable and unequivocally progressive. The author finds that the gap between reformers' ideals and their material circumstances is bridged by the movement's ample production of hope.
Beach Crisis
Authors: West-Newman Catherine Lane
Published: April 2008

Law making can be both a technical solution and an emotional event formed through social context and geopolitical location. When a decision in the New Zealand Court of Appeal raised the question of beach ownership, government rapidly legislated to “resolve” the issue. Events around the passing of the Foreshore and Seabed Act 2004 brought beaches to the forefront of public attention and showed how deeply they occupy national affections. In theory, this was law making to reconcile the different beliefs and values of two ethnicized groups—indigenous Maori and settler non-Maori. In practice, a common love of place was mediated through cultural differences to produce grief, fear, and nostalgia in public life.
Hope and Fear in Biotechnology
Authors: Shields Rob
Published: April 2008

This article draws out temporal and spatial affects such as hope and fear, trust and confidence, and assumptions of actors in plant biotechnology development and its regulation by the Federal Government of Canada. These underlie both insider developers' and regulators' hopes and trust, and outsider experts' and publics' anxiety and fear. Etymologically, hope is rooted in actual capacities or dunamis and in latent potency or potentia . Ethnographic interviews among researchers, producers, and regulators of plant biotechnologies in Canada conducted between 2001 and 2003 provide an empirical illustration of this argument. In the regulatory process for plants with novel traits (PNTs), different affective responses (hope, fear, trust) correlate with social insiders and outsiders around biotechnology generally and PNTs specifically. Insiders form a regulatory figuration in Elias's sense of the term. The spatiotemporal qualities of different affects—dunamis here and now versus the distant and future quality of potentia— “torque” discourse, risk-taking behavior, and calculations of standards of precaution.
Looking beyond teachers' classroom behaviour: Novice and experienced ESL teachers' pedagogical knowledge
Authors: Gatbonton Elizabeth
Published: April 2008

This paper reports a study that examined the categories of pedagogical knowledge (knowledge related to the act of teaching) of novice ESL teachers as gleaned from their verbal reports of what they were thinking about while teaching and compared these categories to those found for experienced teachers in an earlier study (Gatbonton, 1999). The goal was to discover what pedagogical knowledge these learners have internalized after having completed a teacher-training program and how this knowledge compares to that of teachers who have had more experience than they have had. The novice and experienced teachers' pedagogical knowledge were examined specifically in relation to language management (how to handle language input and student output), procedural issues, and handling student reactions and attitudes. The results of the study show that the pedagogical knowledge of novice teachers is comparable to that of experienced teachers in terms of major categories but not in terms of details within these categories. Implications for teacher training are discussed.
The effect of interlocutor proficiency on the collaborative dialogue between Korean as a second language learners
Authors: Kim YouJin , McDonough Kim
Published: April 2008

Previous research has shown that second language (L2) learners reflect on language form when carrying out collaborative activities in L2 classrooms. This study explored which language forms Korean as a second language (KSL) learners focused on and how their linguistic issues were resolved when collaborating with interlocutors from different proficiency levels. Eight intermediate Korean L2 learners interacted with an intermediate interlocutor (n= 8) and with an advanced interlocutor (n = 8). Their collaborative dialogue was analyzed in terms of (a) the occurrence and resolution of lexical and grammatical language-related episodes (LREs) and (b) the patterns of interaction with their interlocutors. Results showed that the collaborative dialogue with advanced interlocutors contained significantly more lexical LREs and correctly resolved LREs. In terms of their patterns of interaction, the learners showed different pair dynamics when collaborating with interlocutors from different proficiency levels. The findings are discussed in terms of the pedagogical implications for the use of collaborative tasks in L2 classrooms.
Understanding how teacher and student talk with each other: An exploration of how `repair' displays the co-management of talk-in-interaction
Authors: Nakamura Ian
Published: April 2008

The essence of my argument is that Practitioner Research can be pursued not only by observing whole classes, but also by observing what happens when a teacher talks to a student outside of the classroom setting. What this setting offers to practitioner-researchers is a unique opportunity to understand what both the teacher and the student do to keep the conversation going. There are implications for reflecting on how teachers actually talk to students and whether what we do helps or hinders them from expressing themselves. Also, such an analytical approach that draws attention to the spoken details of the interaction can show us how to help students take advantage of their turns in an extended talk. Teachers can `recipient-design' what they say and do in order to give students in the next turn `easy' opportunities to use the language they know. In order to demonstrate how this particular discourse genre (informal teacher—student talk) is co-accomplished, features of `repair' as they occur in a sequence of turns will be described and analyzed. They reveal that once the purpose of the talk moves beyond controlled production of correct language forms, the interlocutors' roles and relationship shift from expert and novice to co-participants in managing the talk. Exploration in pursuit of understanding how social interactions are performed can take various forms. This paper offers one example of how it can be done through close observation of the organization of turn-taking.
Developing Cultural Intelligence in Preservice Speech-Language Pathologists and Educators
Authors: Griffer Mona R. , Perlis Susan M.
Published: April 2008

Postsecondary educators preparing future clinicians and teachers have an important responsibility to develop cultural competence of their students in order to meet the increasing and ever-changing demands of today's global workforce and diverse workplace. In this article, the authors discuss key components to developing cultural intelligence. These include an awareness of multiperspective identity, an understanding of the concepts of privilege and difference, the development of one's diversity consciousness, and an understanding of and respect for the guiding principles of cultural competence that lead to an understanding of others. Application to practice is presented through multiperspective identity and role-play activities and a case study with questions for facilitating discussion.
Cultural Intelligence (CQ)
Authors: Cheng Li-Rong Lilly
Published: April 2008

Professionals in the field of special education are constantly being asked about efficacy and outcome-based practice. The tragic event that took place at Virginia Tech shocked the world. This article uses the Virginia Tech tragedy as a base to discuss the need for all professionals to develop cultural competence. Furthermore, it discusses the topic of cultural reactions to communicative disorders and the need to develop cultural competence to decode each message in its cultural, linguistic, and social contexts and to provide culturally appropriate intervention when called for. It also builds on the notion that the world is flat and describes the challenges we face as we try to decode the messages from the world of English-language learners, the world of Englishes, and the codes shared by the e-generation. Finally, it advocates the need to develop cultural humility with the goal to quest for cultural competence.
Got EQ? Increasing Cultural and Clinical Competence Through Emotional Intelligence
Authors: Robertson Shari A.
Published: April 2008

Cultural intelligence has been described across three parameters of human behavior: cognitive intelligence, emotional intelligence (EQ), and physical intelligence. Each contributes a unique and important perspective to the ability of speech—language pathologists and audiologists to provide benefits to their clients regardless of cultural backgrounds. This article provides an overview of the concept of EQ and its historic and theoretical foundations. Strategies for developing and implementing skills related to EQ to enhance clinical competence and cultural proficiency are explored.
Productivity, Fluency, and Grammaticality Measures From Narratives
Authors: Tilstra Janet , McMaster Kristen
Published: April 2008

The purpose of this study was to identify potential general outcome indicators (GOIs) of language proficiency. Brief narratives were elicited from 45 kindergarten, first-grade, and third-grade children using single-picture scenes and a standardized protocol. Measures of language productivity, verbal fluency, and grammaticality were examined for alternate-form reliability and criterion validity. Two verbal fluency measures, total productive words per minute and total number of words per minute, were reliably obtained for students in all grades, demonstrated moderate criterion validity with a standardized oral language measure, and differentiated third-grade students from those in kindergarten and first grade. Additional standards for GOIs are discussed.
Subversion of complement activation at the bacterial surface promotes serum resistance and opsonophagocytosis ofFrancisella tularensis
Authors: Ben Nasr Abdelhakim , Klimpel Gary R
Published: April 2008

Francisella tularensis (Ft) is resistant to serum but requires complement factor C3-derived opsonins for uptake by phagocytic cells and subsequent intracellular growth. In this study, we show that C3 fragments, deposited on Ft, are detected by anti-C3d and -iC3b mAb and that the classical and the alternative pathways are involved in this event. This was demonstrated using C2-depleted sera and specific inhibitors of the classical-versus-alternative pathways of complement activation. Further, we demonstrate that factor C4b, which is crucial for the classical pathway, is deposited on the surface of Ft. In contrast, the C5b-C9 membrane attack complex (MAC) is not assembled on the surface of Ft, which may explain its resistance to complement killing. Deposition of C3 opsonins leads to enhanced phagocytosis by human immature dendritic cells (DC), which leads to intracellular survival, growth, and DC death. Finally, we show that factor H (fH) can bind to the surface of Ft. We believe our data suggest that important virulence factors for Ft are its ability to bind fH and inactivate C3b to iC3b, which culminates in opsonin-induced uptake for subsequent intracellular growth. C3b inactivation also leads to inefficient MAC assembly, which contributes to the ability of this bacterium to resist complement lysis.
Zfp64 participates in Notch signaling and regulates differentiation in mesenchymal cells
Authors: Sakamoto Kei , Tamamura Yoshihiro , Katsube Ken-ichi , Yamaguchi Akira
Published: April 2008

Notch signaling is required for multiple aspects of tissue and cell differentiation. In this study, we identified zinc finger protein 64 (Zfp64) as a novel coactivator of Notch1. Zfp64 is associated with the intracellular domain of Notch1, recruited to the promoters of the Notch target genes Hes1 and Hey1, and transactivates them. Zfp64 expression is under the control of Runx2, and is upregulated by direct transactivation of its promoter. Zfp64 suppresses the myogenic differentiation of C2C12 cells and promotes their osteoblastic differentiation. Our data demonstrate two functions of Zfp64: (1) it is a downstream target of Runx2 and, (2) its cognate protein acts as a coactivator of Notch1, which suggests that Zfp64 mediates mesenchymal cell differentiation by modulating Notch signaling.
Drosophila melanogaster kl-3 and kl-5 Y-loops harbor triple-stranded nucleic acids
Authors: Piergentili Roberto , Mencarelli Caterina
Published: April 2008

Primary spermatocyte nuclei of Drosophila melanogaster contain three prominent lampbrush-like loops. The development of these structures has been associated with the transcription of three fertility factors located on the Y chromosome, named kl-5, kl-3 and ks-1. These loci have huge physical dimensions and contain extremely long introns. In addition, kl-3 and kl-5 were shown to encode two putative dynein subunits required for the correct assembly of the sperm axoneme. Here, we show that both the kl-5 and kl-3 loops are intensely decorated by monoclonal antibodies recognizing triple-stranded nucleic acids, and that each loop presents a peculiar molecular organization of triplex structures. Moreover, immunostaining of Drosophila hydei primary spermatocytes revealed that also in this species – which diverged from D. melanogaster 58 million years ago – Y-loops are decorated by anti-triplex antibodies, strongly suggesting a conserved role of loop-associated triplexes. Finally, we showed that in D. melanogaster wild-type lines that are raised at the non-permissive temperature of 31±0.5°C (which is known to induce male sterility in flies) both the triplex immunostaining and the axonemal dynein heavy chains encoded by kl-3 and kl-5 are no longer detectable, which suggests a functional correlation between loop-associated triplexes, the presence of axonemal proteins and male fertility in fly.
Synthesis and characterization of mRNA cap analogs containing phosphorothioate substitutions that bind tightly to eIF4E and are resistant to the decapping pyrophosphatase DcpS
Authors: Kowalska Joanna , Lewdorowicz Magdalena , Zuberek Joanna , Grudzien-Nogalska Ewa , Bojarska Elzbieta , Stepinski Janusz , Rhoads Robert E. , Darzynkiewicz Edward , Davis Richard E. , Jemielity Jacek
Published: April 2008

Analogs of the mRNA cap are widely employed to study processes involved in mRNA metabolism as well as being useful in biotechnology and medicinal applications. Here we describe synthesis of six dinucleotide cap analogs bearing a single phosphorothioate modification at either the α, β, or γ position of the 5′,5′-triphosphate chain. Three of them were also modified with methyl groups at the 2′-O position of 7-methylguanosine to produce anti-reverse cap analogs (ARCAs). Due to the presence of stereogenic P centers in the phosphorothioate moieties, each analog was obtained as a mixture of two diastereomers, D1 and D2. The mixtures were resolved by RP HPLC, providing 12 different compounds. Fluorescence quenching experiments were employed to determine the association constant (KAS) for complexes of the new analogs with eIF4E. We found that phosphorothioate modifications generally stabilized the complex between eIF4E and the cap analog. The most strongly bound phosphorothioate analog (the D1 isomer of the β-substituted analog m7GppSpG) was characterized by a KAS that was more than fourfold higher than that of its unmodified counterpart (m7GpppG). All analogs modified in the γ position were resistant to hydrolysis by the scavenger decapping pyrophosphatase DcpS from both human and Caenorhabditis elegans sources. The absolute configurations of the diastereomers D1 and D2 of analogs modified at the α position (i.e., m7GpppSG and m27,2′-OGpppSG) were established as SP and RP, respectively, using enzymatic digestion and correlation with the SP and RP diastereomers of guanosine 5′-O-(1-thiodiphosphate) (GDPαS). The analogs resistant to DcpS act as potent inhibitors of in vitro protein synthesis in rabbit reticulocyte lysates.
The Retail Value Chain: Linking Employee Perceptions to Employee Performance, Customer Evaluations, and Store Performance
Authors: Maxham James G. , Netemeyer Richard G. , Lichtenstein Donald R.
Published: April 2008

The authors test a value chain model entailing a progression of influence from retail employee job perceptions → retail employee job performances → customer evaluations → customer spending and comparable store sales growth. The authors test the model using three matched samples of 1,615 retail employees, 57,656 customers, and 306 stores of a single retail chain.

The authors find that three retail employee job perceptions (conscientiousness, perceived organizational justice, and organizational identification) have main and interactive effects on three dimensions of employee job performance (in-role performance, extra-role performance toward customers, and extra-role performance toward the organization). In turn, these performance dimensions exert influence on customer evaluations of the retailer (a satisfaction, purchase intent, loyalty, and word-of-mouth composite). The authors also show that employee perceptions exert a direct influence on customer evaluations, and that customer evaluations affect retail store performance (customer spending and comparable store sales growth).

Finally, the authors conduct some simple simulations that show: (1) how changes in employee perceptions may raise average employee performances; (2) how changes in employee performances enhance average customer evaluations; and (3) how changes in customer evaluations raise average customer spending and comparable store sales growth. The authors then show that employee job perceptions and performances “ripple thru the system” to affect customer spending and store sales growth. The authors offer implications for theory and practice.
Can Inaccurate Perceptions in Business-to-Business (B2B) Relationships Be Beneficial?
Authors: Vosgerau Joachim , Anderson Erin , Ross William T.
Published: April 2008

The authors dedicate this paper in honor of the memory of their deceased co-author, Erin Anderson.

In dyadic business relationships, parties can be incorrect in reading their counterparts' relational closeness. For example, they can overestimate or underestimate the counterpart's commitment to their relationship. In the business-to-business (B2B) literature, the consequences of such inaccurate perceptions have not been empirically investigated. We advance and test the proposition that the impact of misreading the other party's relational closeness depends on the direction of the error. We propose that overestimating the counterpart's relational closeness (CRC) is beneficial, while underestimating the counterpart's relational closeness is detrimental for the relationship's functioning. Using original dyadic data in the service sector, we show that most companies underestimate their CRC, in which case becoming perceptually more accurate would improve their relationships. But the opposite holds for parties that overestimate their CRC, in which case becoming perceptually more accurate would actually make the relationship deteriorate. Furthermore, we show that even in long-standing relationships, companies do not know how accurate their perceptions are, even when they believe that they correctly perceive their CRC. We discuss managerial implications of our findings and encourage future research to determine why most decision makers underestimate their CRC, which can lead to impaired functioning of B2B relationships.
A Hidden Markov Model of Customer Relationship Dynamics
Authors: Netzer Oded , Lattin James M. , Srinivasan V.
Published: April 2008

This research models the dynamics of customer relationships using typical transaction data. Our proposed model permits not only capturing the dynamics of customer relationships, but also incorporating the effect of the sequence of customer-firm encounters on the dynamics of customer relationships and the subsequent buying behavior. Our approach to modeling relationship dynamics is structurally different from existing approaches. Specifically, we construct and estimate a nonhomogeneous hidden Markov model to model the transitions among latent relationship states and effects on buying behavior. In the proposed model, the transitions between the states are a function of time-varying covariates such as customer-firm encounters that could have an enduring impact by shifting the customer to a different (unobservable) relationship state. The proposed model enables marketers to dynamically segment their customer base and to examine methods by which the firm can alter long-term buying behavior. We use a hierarchical Bayes approach to capture the unobserved heterogeneity across customers. We calibrate the model in the context of alumni relations using a longitudinal gift-giving data set. Using the proposed model, we probabilistically classify the alumni base into three relationship states and estimate the effect of alumni-university interactions, such as reunions, on the movement of alumni between these states. Additionally, we demonstrate improved prediction ability on a hold-out sample.
Buyer-Initiated vs. Seller-Initiated Information Revelation
Authors: Bhardwaj Pradeep , Chen Yuxin , Godes David
Published: April 2008

Sales presentations are the core of the selling process where salespeople provide information to prospects. One challenge is that the amount of information available to be potentially communicated may exceed salespeople's ability to communicate or customers' ability to process: there is limited “bandwidth” between the firm and customers. One important decision, then, is which information should customers see? What the firm chooses to tell customers may be informative in itself. When constrained to a “seller-initiated information revelation” format, where the firm chooses which feature to show, the firm never finds it optimal to offer more features than it is able to inform customers about. Consequently, customers never find credible a claim that the product has all features. The important implication is that price alone cannot serve as a signal of quality in this setting. In contrast, a “buyer-initiated information revelation” format, where customers decide which information to receive, increases the probability of a sale and also results in the production of higher quality products.

In a competitive setting, by adopting buyer-initiated information revelation, firms are able to attain positive profits. This is due to the fact that customers infer the product's quality from the price along with the information revelation format. Customers know that at some prices, firms find it profitable to produce high-quality products and at other, lower, prices, this is not the case. Thus, customer empowerment leads to higher profits.
Managed Care: Effect of an Academic Detailing Intervention on the Utilization Rate of Cyclooxygenase-2 Inhibitors in the Elderly
Authors: Graham Stephen D , Hartzema Abraham G , Sketris Ingrid S , Winterstein Almut G
Published: April 2008

Background:

Osteoarthritis is prevalent in the elderly. Nova Scotia general practitioners (GPs) identified the need for an academic detailing (AD) intervention aimed at optimizing the management of osteoarthritis. AD was provided by Dalhousie University Continuing Medical Education in a face-to-face encounter employing evidence-based information. GP participation was voluntary.

Objective:

To evaluate the effect of a GP-targeted osteoarthritis AD intervention on a reduction in the prescribing of cyclooxygenase-2 (COX-2) inhibitors, as well as examine the intervention effect on the utilization rates of gastroprotective agents and medical services.

Methods:

A retrospective cohort study design employing administrative data was used. Differences in utilization rates between intervention and control groups were evaluated using generalized estimating equations analysis for longitudinal data over four 90-day postintervention periods. Confounding was addressed using propensity scores to adjust for between-group bias on the measured covariates.

Results:

The between-group difference for change in COX-2 utilization rates was 0.76 defined daily doses/patient (p = 0.040; 95% CI 0.037 to 1.48) for the 3-month period following the intervention, with lower COX-2 utilization in the AD intervention group than in the control group. The intervention group showed a significant decrease in the within-group utilization rate between the pre- and postintervention periods (z = -2.34; p = 0.019). The between-group difference for change in GP office visit rates was 0.40 visits/patient (p = 0.028; 95% CI 0.046 to 0.79) with the intervention group, showing higher visit rates compared with the control group.

Conclusions:

The osteoarthritis AD intervention was associated with a significant decrease (23%) in COX-2 utilization rates in the 3-month period immediately following the intervention. The only secondary outcome to show a significant between-group effect was the GP office visit rate, which was higher for the intervention group in the second 3-month postintervention period.
Interactions between the Superior Temporal Sulcus and Auditory Cortex Mediate Dynamic Face/Voice Integration in Rhesus Monkeys
Authors: Ghazanfar Asif A. , Chandrasekaran Chandramouli , Logothetis Nikos K.
Published: April 2008

The existence of multiple nodes in the cortical network that integrate faces and voices suggests that they may be interacting and influencing each other during communication. To test the hypothesis that multisensory responses in auditory cortex are influenced by visual inputs from the superior temporal sulcus (STS), an association area, we recorded local field potentials and single neurons from both structures concurrently in monkeys. The functional interactions between the auditory cortex and the STS, as measured by spectral analyses, increased in strength during presentations of dynamic faces and voices relative to either communication signal alone. These interactions were not solely modulations of response strength, because the phase relationships were significantly less variable in the multisensory condition as well. A similar analysis of functional interactions within the auditory cortex revealed no similar interactions as a function of stimulus condition, nor did a control condition in which the dynamic face was replaced with a dynamic disk mimicking mouth movements. Single neuron data revealed that these intercortical interactions were reflected in the spiking output of auditory cortex and that such spiking output was coordinated with oscillations in the STS. The vast majority of single neurons that were responsive to voices showed integrative responses when faces, but not control stimuli, were presented in conjunction. Our data suggest that the integration of faces and voices is mediated at least in part by neuronal cooperation between auditory cortex and the STS and that interactions between these structures are a fast and efficient way of dealing with the multisensory communication signals.
Revealing Past Memories: Proactive Interference and Ketamine-Induced Memory Deficits
Authors: Chrobak James J. , Hinman James R. , Sabolek Helen R.
Published: April 2008

Memories of events that occur often are sensitive to interference from memories of similar events. Proactive interference plays an important and often unexamined role in memory testing for spatially and temporally unique events (“episodes”). Ketamine (NMDA receptor antagonist) treatment in humans and other mammals induces a constellation of cognitive deficits, including impairments in working and episodic memory. We examined the effects of the ketamine (2.5–100 mg/kg) on the acquisition, retrieval, and retention of memory in a delayed-match-to-place radial water maze task that can be used to assess proactive interference. Ketamine (2.5–25 mg/kg, i.p.) given 20 min before the sample trial, impaired encoding. The first errors made during the test trial were predominantly to arms located spatially adjacent to the goal arm, suggesting an established albeit weakened representation. Ketamine (25–100 mg/kg) given immediately after the sample trial had no effect on retention. Ketamine given before the test trial impaired retrieval. First errors under the influence of ketamine were predominantly to the goal location of the previous session. Thus, ketamine treatment promoted proactive interference. These memory deficits were not state dependent, because ketamine treatment at both encoding and retrieval only increased the number of errors during the test session. These data demonstrate the competing influence of distinct memory representations during the performance of a memory task in the rat. Furthermore, they demonstrate the subtle disruptive effects of the NMDA antagonist ketamine on both encoding and retrieval. Specifically, ketamine treatment disrupted retrieval by promoting proactive interference from previous episodic representations.
Measuring Flow Velocity and Flow Direction by Spatial and Temporal Analysis of Flow Fluctuations
Authors: Chagnaud Boris P. , Brücker Christoph , Hofmann Michael H. , Bleckmann Horst
Published: April 2008

If exposed to bulk water flow, fish lateral line afferents respond only to flow fluctuations (AC) and not to the steady (DC) component of the flow. Consequently, a single lateral line afferent can encode neither bulk flow direction nor velocity. It is possible, however, for a fish to obtain bulk flow information using multiple afferents that respond only to flow fluctuations. We show by means of particle image velocimetry that, if a flow contains fluctuations, these fluctuations propagate with the flow. A cross-correlation of water motion measured at an upstream point with that at a downstream point can then provide information about flow velocity and flow direction. In this study, we recorded from pairs of primary lateral line afferents while a fish was exposed to either bulk water flow, or to the water motion caused by a moving object. We confirm that lateral line afferents responded to the flow fluctuations and not to the DC component of the flow, and that responses of many fiber pairs were highly correlated, if they were time-shifted to correct for gross flow velocity and gross flow direction. To prove that a cross-correlation mechanism can be used to retrieve the information about gross flow velocity and direction, we measured the flow-induced bending motions of two flexible micropillars separated in a downstream direction. A cross-correlation of the bending motions of these micropillars did indeed produce an accurate estimate of the velocity vector along the direction of the micropillars.
Low-Serotonin Levels Increase Delayed Reward Discounting in Humans
Authors: Schweighofer Nicolas , Bertin Mathieu , Shishida Kazuhiro , Okamoto Yasumasa , Tanaka Saori C. , Yamawaki Shigeto , Doya Kenji
Published: April 2008

Previous animal experiments have shown that serotonin is involved in the control of impulsive choice, as characterized by high preference for small immediate rewards over larger delayed rewards. Previous human studies under serotonin manipulation, however, have been either inconclusive on the effect on impulsivity or have shown an effect in the speed of action–reward learning or the optimality of action choice. Here, we manipulated central serotonergic levels of healthy volunteers by dietary tryptophan depletion and loading. Subjects performed a “dynamic” delayed reward choice task that required a continuous update of the reward value estimates to maximize total gain. By using a computational model of delayed reward choice learning, we estimated the parameters governing the subjects' reward choices in low-, normal, and high-serotonin conditions. We found an increase of proportion in small reward choices, together with an increase in the rate of discounting of delayed rewards in the low-serotonin condition compared with the control and high-serotonin conditions. There were no significant differences between conditions in the speed of learning of the estimated delayed reward values or in the variability of reward choice. Therefore, in line with previous animal experiments, our results show that low-serotonin levels steepen delayed reward discounting in humans. The combined results of our previous and current studies suggest that serotonin may adjust the rate of delayed reward discounting via the modulation of specific loops in parallel corticobasal ganglia circuits.
CLEC-38, A Transmembrane Protein with C-Type Lectin-Like Domains, Negatively Regulates UNC-40-Mediated Axon Outgrowth and Promotes Presynaptic Development inCaenorhabditis elegans
Authors: Kulkarni Gauri , Li Haichang , Wadsworth William G.
Published: April 2008

In the developing nervous system, axons respond to various guidance cues to find their targets. The effects guidance cues have on an axon may change as an axon undergoes morphological changes, such as branching, turning, and synapse formation. The means by which these changes are regulated are not well understood. InCaenorhabditis elegans, the UNC-40/DCC (deleted in colorectal cancer) receptor mediates responses to the UNC-6/netrin guidance cue. Here, we show that CLEC-38, a protein with predicted transmembrane and C-type lectin-like domains, regulates UNC-40-mediated axon outgrowth as well as the organization of presynaptic terminals. We observe that, in genetic backgrounds sensitized for axon guidance defects, loss ofclec-38function can suppress defects in an UNC-40-dependent manner. Within migrating axons,clec-38acts cell autonomously. Furthermore, loss ofclec-38function alters UNC-40::GFP (green fluorescent protein) expression. We also observe that loss ofclec-38function disrupts presynaptic patterning in animals with normal axon guidance and that there are genetic interactions betweenclec-38andrpm-1, which encodes a protein implicated in regulating presynaptic assembly and axon morphology. We suggest CLEC-38 plays a role in promoting synapse assembly and refining axon outgrowth activity.
Perceptual Decisions between Multiple Directions of Visual Motion
Authors: Niwa Mamiko , Ditterich Jochen
Published: April 2008

Previous studies and models of perceptual decision making have largely focused on binary choices. However, we often have to choose from multiple alternatives. To study the neural mechanisms underlying multialternative decision making, we have asked human subjects to make perceptual decisions between multiple possible directions of visual motion. Using a multicomponent version of the random-dot stimulus, we were able to control experimentally how much sensory evidence we wanted to provide for each of the possible alternatives. We demonstrate that this task provides a rich quantitative dataset for multialternative decision making, spanning a wide range of accuracy levels and mean response times. We further present a computational model that can explain the structure of our behavioral dataset. It is based on the idea of a race between multiple integrators to a decision threshold. Each of these integrators accumulates net sensory evidence for a particular choice, provided by linear combinations of the activities of decision-relevant pools of sensory neurons.
Long-term survival of the nasal NK/T cell lymphoma
Authors: Rajnics Péter , Krenács László , Kenéz András , Járay Zoltán , Bagdi Enikő , Demeter Judit
Published: April 2008

The nasal NK/T cell lymphoma is a rare, extranodal non-Hodgkin lymphoma in western civilizations, which has poor prognosis. The Epstein–Barr virus can be detected in tumor cells in nearly all cases. There are no definite treatment guidelines in our days. There is no significant difference in survival between radiotherapy and chemotherapy according to Asian studies. In this case study we show our diagnostic procedures, our treatment options and we present the summary of this illness based on the data found in the literature.
Postpartum voiding dysfunction
Authors: Kearney Rohna , Cutner Alfred
Published: April 2008

The postpartum bladder is vulnerable to urinary retention; if undetected, this can lead to bladder underactivity, recurrent urinary tract infection and incontinence.

The aim of intrapartum bladder care is to prevent bladder overdistension.

Following delivery or catheter removal, no woman should be allowed to go longer than 6 hours without voiding.

All units should have a guideline for bladder care and the management of postpartum voiding dysfunction.

Learning objectives:

To be aware of the risk factors for the development of postpartum voiding dysfunction and the symptoms indicating voiding problems.

To learn about the management of postpartum voiding dysfunction.

Ethical issues:

Is it acceptable to catheterise a woman to estimate the volume of residual urine when this can be estimated by ultrasound scanning of the bladder?

Please cite this article as: Kearney R, Cutner A. Postpartum voiding dysfunction. The Obstetrician & Gynaecologist 2008;10:71–74.
Tubal disease and assisted reproduction
Authors: Siassakos Dimitrios , Syed Amber , Wardle Peter
Published: April 2008

Surgery can be useful in selected cases of tubal infertility and may have a complementary role for some women undergoingin vitrofertilisation (IVF).

Salpingectomy for women with large hydrosalpinges can improve the success rate of IVF.

There is little evidence that laparoscopy offers any advantage over laparotomy for tubal surgery.

Structured training in reproductive surgical techniques is of critical importance.

Learning objectives:

To understand the selection criteria for tubal surgery and evaluate the supporting evidence.

To understand the limitations of the existing evidence.

To be able to counsel infertile couples appropriately.

Ethical issues:

Couples seeking fertility treatment may receive unreliable or biased information when considering tubal surgery.

Is it ethical to perform tubal surgery on women with a low chance of success simply because they are unable to have IVF?

Please cite this article as: Siassakos D, Syed A, Wardle P. Tubal disease and assisted reproduction.The Obstetrician & Gynaecologist2008;10:80–87.
Cervical insufficiency: prediction, diagnosis and prevention
Authors: Chandiramani Manju , Shennan Andrew H
Published: April 2008

Predicting preterm birth secondary to cervical insufficiency is based mainly on previous history.

Prediction has become more effective with the use of transvaginal ultrasonography and fetal fibronectin.

Prophylactic and reactive interventions remain largely unevaluated or ineffective.

A combination of interventions, including cerclage, progesterone, antibiotics and tocolytics, are routinely used in the clinical management.

Learning objectives:

To understand how predictive tools can guide clinicians in identifying ‘at‐risk’ women.

To be aware of the limitations of research into diagnosis and prevention.

Ethical issues:

How can the risk/benefit of uncertain interventions be balanced in women at high risk?

Please cite this article as: Chandiramani M, Shennan AH. Cervical insufficiency: prediction, diagnosis and prevention. The Obstetrician & Gynaecologist 2008;10: 99–106.
Experiences of a 24‐hour resident consultant service
Authors: Edmonds Simon , Allenby Keith
Published: April 2008

The Royal College of Obstetricians and Gynaecologists supports the Department of Health recommendation to increase consultant presence outside current working hours.

Resident, 24‐hour consultant cover exerts considerable pressure on staff.

Whether permanent consultant presence improves standards of care is unclear.

Learning objectives:

To explore the relationship between evidence in support of a permanent consultant presence and pregnancy outcomes.

To appreciate the advantages, disadvantages and practical considerations of 24‐hour resident consultant cover.

Ethical issues:

Is it possible to balance improvements in the standard of maternity care with potential detrimental effects on NHS staff?

Please cite this article as: Edmonds S, Allenby K. Experiences of a 24‐hour resident consultant service. The Obstetrician & Gynaecologist 2008;10:107–111.
Website reviews @ TOG
Authors: Edey Katharine , Barnfield Sonia , Keay Stephen
Published: April 2008

Returning to our series on allied specialties, we review a series of pharmacology websites. Relevant and recent information about medicines is important for any clinician and can be particularly pertinent when prescribing in pregnancy. The ability to provide information on less frequently used medications helps keep women informed and empowered in their choices.
Response Assessment in Clinical Trials: Implications for Sarcoma Clinical Trial Design
Authors: Jaffe C. Carl
Published: April 2008

Response assessment and design of clinical trials require careful consideration of many factors, especially as validated response criteria can ultimately lead to the approval of an anticancer agent. Current anatomic imaging criteria are difficult to apply for evaluation of certain types of tumors, including soft tissue sarcomas. The emergence of new molecular imaging techniques, such as 64-slice computed tomography scanners and dynamic contrast magnetic resonance imaging, provide complementary information to conventional anatomical imaging. Currently the U.S. National Cancer Institute and the U.S. Food and Drug Administration are aiming to revise existing response criteria based on the development of volumetric anatomic imaging for oncology. Reviewing existing and new approaches in the design of clinical trials will help to optimize the clinical development and evaluation of new therapies for sarcomas.
Endpoints for Assessing Drug Activity in Clinical Trials
Authors: Pazdur Richard
Published: April 2008

Overall survival remains the gold standard for the demonstration of clinical benefit. An improvement in overall survival is a direct clinical benefit to patients. An analysis of overall survival requires larger patient numbers and longer follow-up than other endpoints. Survival analysis may be confounded by subsequent therapies. Time to progression usually requires smaller clinical trials and may be more rapidly assessed than trials using overall survival as an endpoint. This endpoint is not confounded by subsequent therapies. Time to progression must use the same evaluation techniques and schedules for all therapies being evaluated. Blinding of trials or the use of an external blinded radiographic review committee is recommended in assessing time to progression. Unlike overall survival and time to progression, which must be evaluated in randomized trials, response rates can be accurately assessed using a single-arm trial. Stable disease is not included in a response rate determination and is optimally evaluated by assessing tumor progression in a randomized trial. Improvement in disease-related symptoms is considered clinical benefit and may be an appropriate endpoint for drug approval.