bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing narrative interpretation: Structural and content analyses
Authors: Genereux Randy. , McKeough Anne.
Published: January 2008

Background.Narrative thought is a primary mode of human cognition that underpins key human capabilities such as meaning‐making and social‐psychological understanding.

Aims.We sought to further our understanding of the development of narrative thought during adolescence, particularly in terms of the structure and content of narrative interpretations.

Sample.Participants were 151 grade 4 to grade 12 students from six schools in a major urban centre in Western Canada. They included average and high‐average students.

Method.A cross‐sectional design was used with four age groups: 10, 12, 14 and 17 years. Participants read a short story incorporating two substories and multiple layers of meaning. They then summarized it, described the two main characters, generated story morals and answered multiple choice interpretation questions. Responses were scored for both structural complexity and social‐psychological content of narrative thought. Multivariate and univariate analyses of variance were conducted to identify developmental trends.

Results.A clear developmental pattern in structural complexity was discerned in which students were increasingly able to understand complex multiple layers of meaning within a story. A striking shift in social‐psychological thought was also identified as students demonstrated understanding that moved from an intentional focus on immediate and specific mental states to an increasingly interpretive focus on enduring states, character traits and second‐order psychological interpretations.

Conclusion.Significant transformation occurs during adolescence in the structure and content of narrative thought as well as in capacity for the fundamental human endeavour of meaning‐making.
Heteroscedastic one‐factor models and marginal maximum likelihood estimation
Authors: Hessen David J. , Dolan Conor V.
Published: January 2008

In the present paper, a general class of heteroscedastic one‐factor models is considered. In these models, the residual variances of the observed scores are explicitly modelled as parametric functions of the one‐dimensional factor score. A marginal maximum likelihood procedure for parameter estimation is proposed under both the assumption of multivariate normality of the observed scores conditional on the single common factor score and the assumption of normality of the common factor score. A likelihood ratio test is derived, which can be used to test the usual homoscedastic one‐factor model against one of the proposed heteroscedastic models. Simulation studies are carried out to investigate the robustness and the power of this likelihood ratio test. Results show that the asymptotic properties of the test statistic hold under both small test length conditions and small sample size conditions. Results also show under what conditions the power to detect different heteroscedasticity parameter values is either small, medium, or large. Finally, for illustrative purposes, the marginal maximum likelihood estimation procedure and the likelihood ratio test are applied to real data.
Nearly unbiased estimators for the three‐parameter Weibull distribution with greater efficiency than the iterative likelihood method
Authors: Cousineau Denis
Published: January 2008

The maximum likelihood estimation (MLE) method is the most commonly used method to estimate the parameters of the three‐parameter Weibull distribution. However, it returns biased estimates. In this paper, we show how to calculate weights which cancel the biases contained in the MLE equations. The exact weights can be computed when the population parameters are known and the expected weights when they are not. Two of the three weights' expected values are dependent only on the sample size, whereas the third also depends on the population shape parameters. Monte Carlo simulations demonstrate the practicability of the weighted MLE method. When compared with the iterative MLE technique, the bias is reduced by a factor of 7 (irrespective of the sample size) and the variability of the parameter estimates is also reduced by a factor of 7 for very small sample sizes, but this gain disappears for large sample sizes.
Predictors of the therapeutic alliance in group therapy for individuals with treatment‐resistant auditory hallucinations
Authors: Johnson David P. , Penn David L. , Bauer Daniel J. , Meyer Piper. , Evans Elizabeth.
Published: January 2008

Objectives

This study hypothesized that several baseline client characteristics (i.e. age, symptoms, insight, social functioning) would significantly predict client‐rated group alliance in out‐patients with schizophrenia spectrum disorders.

Design

Hierarchical linear modeling (HLM) was used to evaluate the contributions of selected baseline individual client characteristics and group level characteristics to client‐rated group alliance at the sixth session of group therapy. The effect of treatment type (CBT vs. ST) on group alliance and interaction with predictor variables were also analysed. Finally, correlations were computed to explore the relationship between group alliance, attendance, and treatment engagement.

Methods

Sixty‐three out‐patients who had treatment‐resistant auditory hallucinations were randomly assigned to either group CBT, which targeted reduction of distress associated with hallucinations, or group ST, which focused on improving social integration.

Results

Results indicate that a stronger group alliance at the mid‐point of treatment was associated with overall higher levels of group insight, and lower individual autistic preoccupation and social functioning at the baseline assessment. In addition, stronger group alliance was significantly correlated with higher attendance rates and therapists' ratings of treatment compliance.

Conclusions

These findings have implications for determining group composition and identifying clients low in therapeutic engagement. Suggestions for future research on group alliance are also discussed.
Empathy, systemizing, and autistic traits in anorexia nervosa: A pilot study
Authors: Hambrook David , Tchanturia Kate , Schmidt Ulrike , Russell Tamara , Treasure Janet
Published: January 2008

Objectives

This pilot study examined whether patients with anorexia nervosa (AN) would display an empathizing–systemizing psychometric profile similar to that found in autism spectrum disorders (ASD), and whether people with AN would score highly on a measure of autistic traits.

Method

Self‐report measures of empathy, systemizing, and autistic traits were administered to 22 female AN patients and 45 female healthy controls (HC).

Results

AN patients and HCs did not differ significantly in their self‐reported empathy and systemizing. AN patients scored significantly higher than HCs on the autism‐spectrum quotient.

Conclusions

Replication of these findings is required with larger samples and more sensitive measures.
The protest intentions of skilled immigrants with credentialing problems: A test of a model integrating relative deprivation theory with social identity theory
Authors: Grant Peter R.
Published: January 2008

Currently in Canada, there is a widespread underemployment among foreign‐trained immigrants. This is because potential employers often have to evaluate unfamiliar foreign qualifications that, regrettably, are often misunderstood and undervalued. This questionnaire study tested a model that integrates relative deprivation theory with social identity theory to predict the degree to which skilled migrants from Asia and Africa with credentialing problems protest this systemic discriminatory barrier (N =180). In the model, the strength of cultural and national identifications are conceptualized as opposing motivational forces that, along with collective relative deprivation (CRD), directly impact protest intentions. As well, the model specifies that the so‐called ‘affective’ component of CRD consists of an attribution of blame (perceived discrimination) and associated emotions. Structural equation modelling shows that the model is a good fit to the data. As hypothesized, significant path coefficients show that the strength of cultural identity increases and the strength of Canadian identity decreases the degree to which the respondents feel that immigrants suffer discrimination which, in‐turn, influenced their intentions to take protest actions. The implications of these findings for the integration of relative deprivation and social identity theories are discussed.
False signs and the non‐specificity of theory of mind: Evidence that preschoolers have general difficulties in understanding representations
Authors: Leekam Susan. , Perner Josef , Healey Laura , Sewell Claire
Published: January 2008

The discovery that 3‐year‐old children have difficulties understanding false belief has fuelled two decades of research directed at understanding why children have this problem. One unresolved question is whether false belief problems are due to difficulties with mental or representational aspects of mental states. This question has implications for current arguments about the domain specificity of theory of mind in typically developing children and in populations with autism and brain damage. We revisit this question, presenting evidence that preschoolers' difficulty with false belief is not a domain‐specific problem with mental states but a more general difficulty with understanding representations.
Exploring antecedents of individual grieving stages during an anticipated worksite closure
Authors: Blau Gary
Published: January 2008

A grieving stages framework based on Kubler‐Ross (1969) was successfully operationalized and applied to an anticipated worksite closure for 53 complete data employees across four times in a pharmaceutical manufacturing facility. As predicted, the means for denial, bargaining, and depression significantly decreased, while exploration increased. However, anger and acceptance remained stable over time. Grieving stages were used as individual outcomes at Times 2 (N=89), 3 (N=77), and 4 (N=53) in regression analyses to test additional study hypotheses. Perceived contract violation had the strongest influence on grieving stages. Perceived job alternatives became more important for exploration and acceptance of leaving at Time 4. Being the primary income source, having lower core self‐evaluation, and stronger community ties were generally linked to greater employee depression about leaving the company across times. Additional applications for the suggested grieving stages measure are needed in future job loss research.
The event reconstruction method: An efficient measure of experience‐based job satisfaction
Authors: Grube Anna , Schroer Joachim , Hentzschel Carolin , Hertel Guido
Published: January 2008

Job satisfaction is predominantly measured as global attitudinal judgment which requires employees to summarize their experiences across different job situations. In contrast, experience‐based measures assess momentary thoughts and feelings of the employees in specific job situations. This paper introduces the event reconstruction method (ERM) as an efficient measure of experience‐based job satisfaction that is less invasive and less time consuming compared with traditional experience sampling methods. An initial validation study is reported with N=193 employees from a German wholesale company. As expected, job satisfaction measured with the ERM was different from attitudinal job satisfaction. Also, consistent with expectations, experience‐based job satisfaction was a better predictor of self‐reported helping behaviour, whereas attitudinal job satisfaction was a better predictor of turnover intentions. Finally, comparing the ERM results with the results of a similar study using a traditional experience sampling method (Fisher, 2002) revealed very similar patterns.
Exploring the linkages between formal ownership and psychological ownership for the organization: The mediating role of organizational justice
Authors: Chi Nai‐Wen , Han Tzu‐Shian
Published: January 2008

Extending previous research on formal ownership and psychological ownership in organizations, this study simultaneously examines the relationships between employee participation in three formal ownership programmes (i.e. profit sharing, participation in decision making, access to business information) and psychological ownership for the organization, while also exploring the mediating roles of distributive and procedural justice. Data were collected from 387 R&D engineers based at 20 high‐technology firms in Taiwan. A structural equation modelling analysis was conducted to test our hypotheses, and the results show that employee participation in profit sharing, decision making, and access to business information were all positively related to psychological ownership. Moreover, distributive justice fully mediated the relationship between participation in profit sharing and psychological ownership, while procedural justice mediated the relationship between participation in decision making, access to business information, and psychological ownership.
Playing Devil's advocate†: The case against fMRI lie detection
Authors: Spence Sean A.
Published: January 2008

The advent of functional neuroimaging raises the intriguing possibility that investigators might be able to determine (one day) whether an individual is lying or telling the truth, according to the activity of their brain. Ultimately, such techniques might be applied in the forensic sphere. However, the empirical data supporting this conjecture derive from a body of work that is still early on in its development. Hence, when invited to play ‘Devil's advocate’, the author is prompted to critique a pivotal weakness within the current literature. The latter comprises 16 peer‐reviewed functional magnetic resonance imaging studies purporting to describe the neural correlates of lying. Most have demonstrated greater activation of prefrontal regions while participants lie relative to when they tell the truth. Most have failed to detect areas where truthfulness elicits specific activation (consistent with the view that truthfulness constitutes a ‘baseline’ in human cognition and communication; while lying requires something more). However, there is a great deal of variation between the findings described and, crucially, there is an absence of replication by investigators of their own findings. Hence, basic issues of reliability need to be addressed before functional neuroimaging is applied to cases that matter in the ‘real world’.
Detection of deception with fMRI: Are we there yet?
Authors: Langleben Daniel D.
Published: January 2008

A decade of spectacular progress in functional magnetic resonance imaging (fMRI) technology and systems neuroscience research has so far yielded few changes in our daily lives. The dearth of clinical applications of this prolific and academically promising research tool began raising the eyebrows of the public and the research funding agencies. This may be one of the reasons for the enthusiasm and interest paid to the growing body of literature suggesting that blood oxygenation level‐dependent (BOLD) fMRI of the brain could be sensitive to the differences between lie and truth. The word ‘differences’ is critical here since it refers to the often‐ignored core concept of BOLD fMRI: it is only sensitive to differences between two brain states. Thus, available studies report using fMRI to discriminate between lie and truth or some other comparative state rather than to positively identify deception. This nuance is an example of the extent to which applied neuroscience research does not lend itself to the type of over‐simplification that has plagued the interpretation of fMRI‐based lie detection by the popular press and the increasingly vocal academic critics. As an early contributor to the modest stream of data on fMRI‐based lie detection, I was asked by Dr Aldert Vrij to write a piece in favour of fMRI‐based lie detection, to be contrasted with a piece by Dr Sean Spence presenting an opposite point of view (Spence, 2008). This seemingly straightforward task presented two hurdles: having to respond to the popular as well as scientific view of what lie detection with fMRI is and present a wholly positive view of evolving experimental data.
Real‐world problem solving and quality of life in older people
Authors: Gilhooly M. L. , Gilhooly K. J. , Phillips L. H. , Harvey D. , Brady A. , Hanlon P.
Published: January 2008

Objectives. This study examined relationships between quality of life (QoL) in older people and cognitive functioning in both abstract and real‐world problem solving.

Design. Contributions of levels of mental, physical and social activities, self‐rated and objective health status, self‐rated cognitive functioning, socio‐economic status, gender, real‐world and abstract problem solving were examined in a regression study of factors related to QoL in older people.

Method. Participants (N = 145) were 70–91 years of age. The current cognitive functioning was assessed by psychometric tests and real‐world problem‐solving tasks. Prior functioning was indexed by crystallized ability measures. QoL was assessed using the Leiden‐Padua questionnaire (LEIPAD), Faces scales and Hospital and Anxiety Depression Scale. A single QoL factor was derived.

Results. Simultaneous multiple regressions indicated that QoL was related to real‐world but not to abstract problem‐solving ability. Separate contributions to QoL were also found for health and self‐rated cognitive functioning.

Conclusions. The present study replicates previous findings that abstract problem‐solving ability is not related to QoL and supports the hypothesis that real‐world or everyday problem‐solving ability is associated with QoL in older people.
Post‐traumatic growth in advanced cancer patients receiving palliative care
Authors: Mystakidou Kyriaki , Tsilika Eleni , Parpa Efi , Galanos Antonis , Vlahos Lambros
Published: January 2008

Goals of work To develop the Greek version of the Post‐traumatic Growth Inventory (PTGI‐Gr), and assess its psychometric properties in a palliative care patient sample.

Patients and methods The scale was translated with the forward–backward procedure to Greek. It was administered twice, with a 3‐day interval, to 131 eligible patients with advanced cancer. Together with the PTGI, the patients also completed the Greek version of the Impact of Events Scale‐Revised scale (IES‐R‐Gr). The reliability was assessed by the internal consistency (Cronbach's alpha coefficients), test/retest (Spearman's r value), and inter‐item correlations. Validity was demonstrated by factor analysis, inter‐scale correlations, construct validity with the IES‐R‐Gr, and combined with the Eastern Cooperative Oncology Group (ECOG) performance status.

Main results The PTGI‐Gr yielded a five‐factor structure, explaining 73.5% of the variance. Cronbach's alphas for the five factors ranged from .66 to .87, respectively. Overall test–retest reliability was satisfactory with a range between .85 and .92 (p<.0005), and inter‐item correlations ranged between .47 and .63. Inter‐scale correlations were found satisfactory (p<.0005, p<.005, and p<.05). Validity as performed using combined validity analysis showed good results. Satisfactory construct validity was supported by the correlation analysis between the PTGI‐Gr and the IES‐R‐Gr scales.

Conclusions PTGI‐Gr is an instrument with satisfactory psychometric properties, and is a valid research tool for the post‐traumatic growth of advanced cancer patients.
Working memory capacity can be improved by expressive writing: A randomized experiment in a Japanese sample
Authors: Yogo Masao , Fujihara Shuji
Published: January 2008

This study examined the influence of expressive writing on working memory capacity (WMC), a component of executive function. Japanese undergraduates (N = 104) were individually tested across six separate experimental sessions (baseline, three writing, and two follow‐up sessions at 1 and 5 weeks). Participants were randomly assigned to write about a traumatic experience, their best possible future selves (BPS), or a trivial topic for 20 minutes. WMC tests were completed at baseline and follow‐ups. Results indicate that expressive writing about traumatic experience can improve WMC at 5 weeks after writing, but that writing about BPS or trivial topics has no effect on WMC.
Comparing solutions to the expectancy‐value muddle in the theory of planned behaviour
Authors: O' Sullivan B. , McGee H. , Keegan O.
Published: January 2008

Objectives The authors of the Theories of Reasoned Action (TRA) and Planned Behaviour (TPB) recommended a method for statistically analysing the relationship between the indirect belief‐based measures and the direct measures of attitude, subjective norm, and perceived behavioural control (PBC). However, there is a growing awareness that this yields statistically uninterpretable results. This study's objective was to compare two solutions to what has been called the ‘expectancy‐value muddle’. These solutions were (i) optimal scoring of modal beliefs and (ii) individual beliefs without multiplicative composites.

Design Cross‐sectional data were collected by telephone interview.

Methods Participants were 110 first‐degree relatives (FDRs) of patients diagnosed with colorectal cancer (CRC), who were offered CRC screening in the study hospital (83% response rate). Participants were asked to rate the TPB constructs in relation to attending for CRC screening.

Results There was no significant difference in the correlation between behavioural beliefs and attitude for rescaled modal and individual beliefs. This was also the case for control beliefs and PBC. By contrast, there was a large correlation between rescaled modal normative beliefs and subjective norm, whereas individual normative beliefs did not correlate with subjective norm.

Conclusions Using individual beliefs without multiplicative composites allows for a fairly unproblematic interpretation of the relationship between the indirect and direct TPB constructs (French & Hankins, 2003). Therefore, it is recommended that future studies consider using individual measures of behavioural and control beliefs without multiplicative composites and examine a different way of measuring individual normative beliefs without multiplicative composites to that used in this study.
Self construction in schizophrenia: A discourse analysis
Authors: Meehan Trudy , MacLachlan Malcolm
Published: January 2008

Objectives. Lysaker and Lysaker (Theory and Psychology, 12 (2), 207–220, 2002) employ a dialogical theory of self in their writings on self disruption in schizophrenia. It is argued here that this theory could be enriched by incorporating a discursive and social constructionist model of self. Harré's model enables researchers to use subject positions to identify self construction in people with a diagnosis of schizophrenia that the dialogical model, using analysis of narrative, does not as easily recognize.

Methods. The paper presents a discourse analysis of self construction in eight participants with a diagnosis of schizophrenia. Transcripts from semi‐structured interviews are analysed, wherein focus falls on how participants construct self in talk through the use of subject positioning.

Results. The findings indicate that Harré's theory of self and the implied method of discourse analysis enables more subtle and nuanced constructions of self to be identified than those highlighted by Lysaker and Lysaker (Theory and Psychology, 12 (2), 207–220, 2002). The analysis of subject positions revealed that participants constructed self in the form of Harré's (The singular self: An introduction to the psychology of personhood, 1998, London: Sage) self1, self2, and self3. The findings suggest that there may be constructions of self used by people diagnosed with schizophrenia that are not recognized by the current research methods focusing on narrative. The paper argues for the recognition of these constructions and by implication a model of self that takes into account different levels of visibility of self construction in talk.
Influence of Medical Needle Characteristics on the Resistance to Puncture of Protective Glove Materials
Authors: Dolez Patricia I. , Vu-Khanh Toan , Nguyen C. Thang , Guero Gbeuli , Gauvin Chantal , Lara Jaime
Published: January 2008

Puncture of protective clothing by medical needles is a major concern for a number of professional groups. This is particularly true since it has been shown that the protection level of protective gloves measured using the current puncture resistance standards is not relevant when dealing with medical needles. This paper proposes a step-by-step analysis of the puncture mechanism of membranes by medical needles. It investigates also the influence on the puncture force of various characteristics of medical needles, including the needle diameter, number of facets, and facet angle, for a number of materials relevant to protective gloves. It is observed that the effect of these parameters is sometimes very dependent on the type of material punctured. Tests also reveal that the variation in the measured puncture force for mass-produced three-facet medical needles can be associated with the variation of one of the needle dimensions, i.e., the outer diameter at the transition between the facets. Finally, a study of the effect of needle reuse in successive trials shows that cutting-edge wear is much more extensive with reinforced materials. This justifies the need to use needles only once for measuring the puncture resistance of protective clothing materials.
In VivoImaging Reveals Dissociation between Caspase Activation and Acute Neuronal Death in Tangle-Bearing Neurons
Authors: Spires-Jones Tara L. , de Calignon Alix , Matsui Toshifumi , Zehr Cindy , Pitstick Rose , Wu Hai-Yan , Osetek Jennifer D. , Jones Phillip B. , Bacskai Brian J. , Feany Mel B. , Carlson George A. , Ashe Karen H. , Lewis Jada , Hyman Bradley T.
Published: January 2008

Accumulation of neurofibrillary tangles (NFTs) in Alzheimer's disease correlates with neuronal loss and cognitive decline, but the precise relationship between NFTs and neuronal death and downstream mechanisms of cell death remain unclear. Caspase cleaved products accumulate in tangles, implying that tangles may contribute to apoptotic neuronal death. To test this hypothesis, we developed methods using multiphoton imaging to detect both neurofibrillary pathology and caspase activation in the living mouse brain. We examinedrTg4510mice, a reversible mouse model of tauopathy that develops tangles and neuronal loss. Only a small percentage of imaged neurons were caspase activity positive, but the vast majority of the cells with active caspases contained NFTs. We next tested the hypothesis that caspase activation led to acute, apoptotic neuronal death. Caspase positive cell bodies did not degenerate over hours of imaging, despite the presence of activated executioner caspases. Suppression of the transgene, which stops ongoing death, did not suppress caspase activity. Finally, histochemical assessments revealed evidence of caspase-cleaved tau, but no TUNEL (terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling) positive or apoptotic nuclei. With the novel technique of observing NFTs and caspase activation in the living brain, we demonstrate that aggregated tau in neurons can be associated with caspase activation, but that caspase activation is not sufficient to cause acute neuronal death in this model.
Background Firing Rates of Orbitofrontal Neurons Reflect Specific Characteristics of Operant Sessions and Modulate Phasic Responses to Reward-Associated Cues and Behavior
Authors: Kravitz Alexxai V. , Peoples Laura L.
Published: January 2008

The orbitofrontal cortex plays an important role in the ability of animals to adjust their behavior in response to behavioral outcomes. Multiple studies have demonstrated that responses of orbitofrontal neurons during operant sessions reflect the outcome of particular behaviors. These studies have focused on rapid neural responses to short-duration events such as instrumental behavior and reward-associated discrete cues. We hypothesize that longer-lasting changes in firing are also important for information processing in the orbitofrontal cortex. In the present study, we recorded the activity of 115 single orbitofrontal neurons during a multiphase operant task in which the relationship between a lever-press response and a sucrose reward was varied between the different phases. Approximately one-half of the orbitofrontal neurons exhibited a change in background firing during the operant phases. These changes were observable across multiple behavioral and stimulus events and thus reflected a general shift in background firing. The majority of changes were selective for one or the other of the operant phases. Selective changes contributed to unique patterns of phasic firing time locked to cues and operant behavior in the two operant phases. These findings are consistent with the interpretation that changes in background firing of orbitofrontal neurons reflect operant session characteristics associated with behavioral outcome, and indicate further that changes in background firing contribute to the outcome selectivity of phasic firing patterns. More generally, we propose that the background firing rates of orbitofrontal neurons reflect contextual information, and facilitate context-appropriate event-related information processing and behavioral responses.
Hand Movement Direction Decoded from MEG and EEG
Authors: Waldert Stephan , Preissl Hubert , Demandt Evariste , Braun Christoph , Birbaumer Niels , Aertsen Ad , Mehring Carsten
Published: January 2008

Brain activity can be used as a control signal for brain–machine interfaces (BMIs). A powerful and widely acknowledged BMI approach, so far only applied in invasive recording techniques, uses neuronal signals related to limb movements for equivalent, multidimensional control of an external effector. Here, we investigated whether this approach is also applicable for noninvasive recording techniques. To this end, we recorded whole-head MEG during center-out movements with the hand and found significant power modulation of MEG activity between rest and movement in three frequency bands: an increase for ≤7 Hz (low-frequency band) and 62–87 Hz (high-γ band) and a decrease for 10–30 Hz (β band) during movement. Movement directions could be inferred on a single-trial basis from the low-pass filtered MEG activity as well as from power modulations in the low-frequency band, but not from the β and high-γ bands. Using sensors above the motor area, we obtained a surprisingly high decoding accuracy of 67% on average across subjects. Decoding accuracy started to rise significantly above chance level before movement onset. Based on simultaneous MEG and EEG recordings, we show that the inference of movement direction works equally well for both recording techniques. In summary, our results show that neuronal activity associated with different movements of the same effector can be distinguished by means of noninvasive recordings and might, thus, be used to drive a noninvasive BMI.
Reducing complications associated with a deeply engaged head at caesarean section: a simple instrument
Authors: Singh Mandeep , Varma Rajiv
Published: January 2008

Key content

There has been a disproportionate increase in caesarean section performed in the second stage of labour in the last few years.

Difficult delivery of the fetal head during caesarean section carries a higher risk of complications for both mother and baby.

The National Sentinel Caesarean Section Audit Report, published by the Royal College of Obstetricians and Gynaecologists recommends a consultant presence when caesarean section is performed at full dilatation.

Learning objectives

The obstetrician needs to anticipate the possibility of difficult delivery of the fetal head during caesarean section.

Using an assistant to push the fetus can cause trauma, as the force required to push is uncontrolled.

The Foetal Disimpacting System® seems to be effective in elevating the fetal head when it is deeply engaged.

Ethical issues

There is a need for more data before the fetal disimpacting device is adopted in routine obstetric practice.

Use of this device when preparing for an emergency caesarean section, for instance in a situation of umbilical cord prolapse, may be justified.

Please cite this article as: Singh M, Varma R. Reducing complications associated with a deeply engaged head at caesarean section: a simple instrument. The Obstetrician & Gynaecologist 2008;10:38–41.
The ethics of preimplantation genetic diagnosis
Authors: El‐Toukhy Tarek , Williams Clare , Braude Peter
Published: January 2008

Key content

Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis and termination of affected pregnancies.

PGD for late‐onset and susceptibility conditions requires careful consideration on a case‐by‐case basis.

PGD for sex selection for nonmedical reasons is prohibited in the UK.

The use of PGD is expanding and its ethical implications are likely to increase.

Learning objectives

To recognise the main ethical difficulties raised by the practice of PGD.

To understand the role of regulation.

To appreciate the potential ethical implications of new developments in reproductive genetics.

Ethical issues

Is PGD more acceptable than prenatal diagnosis and termination for all disorders?

Should PGD be offered for Huntington disease on a nondisclosure basis?

Should noncarrier embryos be replaced in preference to carrier embryos in recessive conditions?

Is PGD for HLA typing a step too far?

Please cite this article as: El‐Toukhy T, Williams C, Braude P. The ethics of preimplantation genetic diagnosis. The Obstetrician & Gynaecologist 2008;10:49–54.
Fish Community Responses to Half-Log Additions in Warmwater Streams
Authors: Hrodey Peter J. , Sutton Trent M.
Published: January 2008

Half-log habitat enhancement structures are commonly used for stream restoration projects to increase fish abundance and biomass. Half logs (N = 108) were added to nine headwater streams of the upper Wabash River basin, Indiana, in July 2003. Study sites (25 m in length) were sampled with backpack electrofishing once each month during July–October 2003 and April–September 2004 to document the colonization and use of half logs by fish under agriculture, forest, and fallow-field land uses. Index of biotic integrity (IBI) scores did not change significantly after half-log additions. The effects of half-log habitat enhancement structures were variable by month, stream, and in some cases, individual fish species. Species richness and biomass significantly increased in two study streams during spring and fall due to the presence of bluntnose minnow Pimephales notatus and longear sunfish Lepomis megalotis. Absolute abundance within most sites increased during periods of low flow and high temperature in late summer and early fall, when fish are most vulnerable to predation and require habitat refugia. Fish use of half logs was also dictated by the amount of instream habitat, especially where percentages of aquatic vegetation (mean = 0.0%) and large woody debris (mean = 0.67%) were low and the percentage of pool habitat was moderate (mean = 10.53%). In this study, we found that with the exception of IBI scores, significant manipulation response was variable by stream and species and was influenced by instream habitat and time of year.
Effects and Utility of Minimum Length Limits and Mortality Caps for Flathead Catfish in Discrete Reaches of a Large Prairie River
Authors: Makinster Andrew S. , Paukert Craig P.
Published: January 2008

Populations of flathead catfish Pylodictis olivaris in four reaches of the Kansas River, Kansas, were examined to evaluate the effects of three minimum length limits (305 (the minimum size that anglers are willing to harvest), 610, and 762 mm total length (TL)) on population size structure and number harvested over a 30-year simulation. We used electrofishing and hoopnetting to capture and tag flathead catfish throughout the Kansas River from 2005–2006. Current exploitation (u) based on tag returns was probably less than 10%, and total annual mortality A ranged from 14% to 28% across all reaches. Increased river access and promotion of this fishery may increase u in the future, so model simulations were conducted with conditional natural mortality (cm) and u ranging from 10% to 40%. Proportional stock density (PSD) and the relative stock density of preferred-length fish (RSD-P) substantially declined (by >25% and >15%, respectively) as u increased with the 305-mm TL limit over the 30-year simulation. The PSD showed similar trends across all reaches, indicating that use of different regulations among reaches was not necessary and that differences in growth among reaches were less influential than u and cm. No substantial differences were observed in size structure under the 610- and 762-mm TL limits among reaches, but under a 762-mm TL limit anglers would have to sacrifice about 42% of the number harvested under the current cm level. Mortality caps revealed that each reach could sustain an A of about 60% and 55% to maintain current PSD and RSD-P levels, respectively; this result suggests that quality flathead catfish size structure can be preserved. Our results show that the effects (or lack thereof) on flathead catfish and other sport fishes should be evaluated before harvest restrictions are implemented.
Efeito da radiação gama na absorção de água e no tempo de cocção em cultivares de soja
Authors: Toledo Taís Carolina Franqueira de , Canniatti-Brazaca Solange Guidolin , Arthur Valter , Piedade Sonia Maria de Stefano
Published: January 2008

A soja é uma das mais importantes oleaginosas cultivadas no mundo. Seu alto teor de proteínas a torna alternativa importante para a alimentação animal e humana, além de seus subprodutos. Embora no Brasil haja grande produção de soja, ocorrem muitas perdas devido a alterações nas características físico-químicas, resultando em produto com elevada resistência ao cozimento. Vários métodos podem ser empregados para minimizar esse efeito, dentre os quais a radiação ionizante com Cobalto-60 que constitui um método seguro e eficaz para o aumento no tempo de vida útil dos alimentos. Devido a importância comercial da soja, possíveis alterações promovidas pelo tratamento de irradiação devem ser estudadas. O presente trabalho visou à avaliação das alterações na capacidade de hidratação e no tempo de cocção das variedades de soja BRS 212, BRS 213, BRS 214, BRS 231 e E48 submetidas a doses de 2, 4 e 8 kGy de radiação gama. A quantidade de água absorvida pelos grãos variou de 14,00 a 16,66 mL, e o tempo de cocção de 119,67 a 291,33 minutos. A irradiação causou aumento da velocidade de hidratação, mas não da quantidade de água absorvida. O tempo de cocção diminuiu com o aumento da dose irradiada.
Tolerância ao alumínio em cultivares de aveia branca sob cultivo hidropônico
Authors: Silva José Antonio Gonzalez da , Carvalho Fernando Irajá Félix de , Coimbra Jefferson Luís Meirelles , Vieira Eduardo Alano , Benin Giovani , Oliveira Antônio Costa de , Finatto Taciane , Bertan Ivandro , Silva Giovani Olegário da , Correa Maicon Rubira
Published: January 2008

O emprego do cultivo hidropônico para avaliar a tolerância à toxicidade pelo alumínio em genótipos de aveia pode ser feito por meio da medida da retomada do crescimento de raiz. Avaliaram-se 12 cultivares de aveia branca indicadas para o cultivo no Sul do Brasil com o intuito de caracterizar a tolerância ao alumínio, de maneira a ser estrategicamente recomendadas e/ou incluídas em blocos de cruzamento na obtenção de constituições genéticas de elevado potencial produtivo e tolerante ao íon metálico. Foram utilizadas doses de 10, 15 e 20 mg L-1 de alumínio na solução hidropônica e o delineamento experimental adotado foi o completamente casualizado, com três repetições, seguindo o esquema fatorial (12 x 3). As doses empregadas são altamente eficientes na identificação de genótipos de aveia tolerantes e sensíveis ao alumínio tóxico. As cultivares UPF 16, URS 21, UFRGS 14, UPF 19 e UFRGS 17 expressam tolerância.
Formação de palhada por braquiárias para adoção do sistema plantio direto
Authors: Timossi Paulo César , Durigan Julio Cezar , Leite Gilson José
Published: January 2008

Com o objetivo de avaliar espécies forrageiras para formação de palhada para adoção do sistema plantio direto, foi pesquisado o potencial de Brachiaria decumbens e B. brizantha, comparadas ao milheto (Pennisetum glaucum). As plantas de cobertura foram semeadas em março e conduzidas até novembro (momento do manejo químico). Aos 50, 110 e 250 dias após a semeadura (DAS) foram avaliadas a composição específica das infestantes na cobertura vegetal, a porcentagem visual de cobertura do solo e o acúmulo de massa vegetal seca das coberturas. As braquiárias foram eficientes na formação de palha (acima de 11 tha-1), sendo promissoras para o sistema plantio direto. Também, observou-se densa cobertura do solo, com supressão do desenvolvimento de plantas daninhas, o que não se percebeu com milheto, cujo maior potencial de cobertura do solo e acúmulo (10,5 t ha-1) de massa ocorreu no fim do seu ciclo (110 DAS) e, 3,2 t ha-1 de massa vegetal seca aos 250 DAS. Devido à rápida decomposição da palha de milheto observou-se, também, reinfestação da área por plantas daninhas.
Efeito da infestação de Enneothrips flavens moulton sobre o desenvolvimento de cultivares de amendoim
Authors: Lourenção André Luiz , Moraes Andrea Rocha Almeida de , Godoy Ignácio José de , Ambrosano Gláucia Maria Bovi
Published: January 2008

Com o objetivo de avaliar a influência do ataque de Enneothrips flavens Moulton (Thysanoptera: Thripidae), no desenvolvimento de cultivares de amendoim, foi implantado um experimento em campo, no ano agrícola de 2001/2002, nas localidades paulistas de Campinas e Pindorama. Avaliaram-se IAC-Tatu-ST, IAC 5 e IAC 22, cultivares de porte ereto e Runner IAC 886, Tégua e IAC-Caiapó, de porte rasteiro, com e sem controle químico da praga. O delineamento adotado foi o de blocos ao acaso, com parcelas subdivididas, com seis repetições, onde as parcelas corresponderam aos tratamentos com e sem controle químico do tripes, e as subparcelas, às cultivares de amendoim. Para a avaliação da infestação de tripes, foram realizadas amostragens a partir dos 29 dias após o plantio (DAP), quando se coletaram dez folíolos fechados por subparcela. Para a contagem do número de brotos por planta, coletaram-se cinco plantas por parcela a partir dos 29 DAP, até próximo ao final do ciclo das cultivares. Determinou-se a matéria seca das plantas somente em Campinas, coletando-se cinco plantas por parcela, aos 29, 56, 85, 99, 112 e 125 DAP, com posterior secagem artificial da parte vegetativa e da parte reprodutiva. Foram observadas nas plantas de todas as cultivares, nas parcelas não tratadas, as maiores infestações de E. flavens aos 56-57 DAP, e em Pindorama houve um pico de infestação inicial aos 29 DAP. Em função da cultivar, a falta de controle do tripes acarretou diminuição na emissão de brotos e no desenvolvimento vegetativo das plantas.
Fitoextração de cádmio e zinco de um latossolo vermelho-amarelo contaminado com metais pesados
Authors: Zeittouni Carolina de Freitas , Berton Ronaldo Severiano , Abreu Cleide Aparecida de
Published: January 2008

Avaliou-se a capacidade das plantas de mamona, girassol, pimenta da amazônia e tabaco, cultivadas em vasos de 3 L, em casa de vegetação, em extrair metais de um Latossolo Vermelho-Amarelo distrófico. O delineamento experimental foi em blocos ao acaso, esquema fatorial 4 espécies x 3 doses de metais x 2 doses de EDTA (Ácido Etilenodiaminotetraacético), com três repetições. As doses empregadas de metais, aplicadas na forma de sais inorgânicos foram, em mg kg-1: dose zero - sem adição de metal; dose 1 - adição conjunta de 0,75 de Cd, 6,25 de Pb, 20,0 de Cu, 8,75 de Ni e 62,5 de Zn e; dose 2 - adição conjunta de 1,5 de Cd, 12,5 de Pb, 40,0 de Cu, 17,5 de Ni e 125,0 de Zn, na presença (1 mmol kg-1) e ausência de EDTA. A colheita da parte aérea das quatro espécies de plantas variou de 48 dias (pimenta) até 100 dias (tabaco). A aplicação do EDTA diminuiu a produção de matéria seca da parte aérea de todas as plantas, embora tenha provocado aumento na concentração de Cd na parte aérea da mamoneira e do girassol e nenhuma influência na concentração de Cd (pimenta e tabaco) e na de Zn em todas as espécies. Concluiu-se que a planta mais eficiente em extrair o Cd e o Zn do solo enriquecido com metais foi o tabaco (Nicotiana tabacum) e que para descontaminar o solo, será necessário um maior número de cultivos para todas as culturas, com exceção da mamoneira, se houver a aplicação de EDTA na dose de 1 mmol kg-1.
Caracteristicas físicas e químicas de goiabas 'Cortibel 1' e 'Cortibel 4' armazenadas em condições ambientais
Authors: Mendonça Romário Delbons , Ferreira Karla Silva , Souza Leandro Marelli de , Marinho Cláudia Sales , Teixeira Sílvio Lopes
Published: January 2008

A seleção genótipos de goiabeiras cujos frutos tenham maior vida de prateleira é estratégica para que mercados distantes sejam alcançados. Esse trabalho teve como objetivo avaliar o efeito do tempo de armazenamento pós-colheita sobre algumas características físicas e químicas de goiabas das cultivares Cortibel 1 (de polpa vermelha) e Cortibel 4 (de polpa branca), selecionadas no Estado do Espírito Santo. O experimento foi desenvolvido em condições ambientes (temperatura de 24,1°C ± 1,0 ºC e umidade relativa do ar média de 74,1% ± 4,3%). Foi utilizado o delineamento inteiramente casualizado, em esquema fatorial 2 x 6, no qual foram avaliadas as duas cultivares em épocas distintas (2, 4, 6, 8, 12 e 16 dias após a colheita) com cinco repetições. A parcela experimental foi composta por quatro frutos amostrados aleatoriamente. Foram avaliadas as seguintes características: cor da casca, firmeza da polpa, perda de massa, umidade, matéria seca, acidez titulável, pH, teores de pectina, celulose e lignina, hemicelulose, carotenóides totais, sólidos solúveis, teores de glicose, frutose e sacarose. O completo amarelecimento da casca ocorreu a partir do 12.º dia em ambas as cultivares e os frutos mantiveram-se íntegros até o 16.º dia após a colheita. Obervou-se na 'Cortibel 1' maiores teores de carotenóides e menores teores de açúcares que na 'Cortibel 4'.
Modelagem matemática para o aproveitamento da biomassa residual de colheita da cana-de-açúcar com menor custo
Authors: Tolentino Gilmar , Florentino Helenice de Oliveira , Sartori Maria Márcia Pereira
Published: January 2008

O palhiço derivado da colheita de cana-de-açúcar crua, com a redução gradativa das queimadas nos canaviais, tornou-se foco para os pesquisadores e produtores. As vantagens no recolhimento, na recuperação e no aproveitamento têm mobilizado pesquisadores de universidades, gerentes e diretores de usinas, interessados em encontrar a maneira mais produtiva, econômica e eficaz de realizar esse processo. O recolhimento do palhiço é feito em quatro estágios: primeiro o palhiço é enleirado, depois passado por uma máquina de compactação, posteriormente, acondicionado no caminhão e, finalmente, transportado para o centro de processamento. O estudo da viabilidade de aproveitamento desse resíduo para a geração de energia pode ser feito com base no custo e no balanço de energia, ou seja, a energia gerada por essa biomassa menos a energia consumida no processo. Neste trabalho, é proposto o uso de técnicas matemáticas para auxiliar na escolha das variedades da cana-de-açúcar a serem plantadas a fim de otimizar o balanço de energia da biomassa residual de colheita e minimizar o custo de coleta dessa biomassa do campo para o centro de produção, além de satisfazer as principais necessidades da usina.