bluuebunny/crossref_metadata_2025 huggingface dataset:
A longitudinal study of students' academic self‐concept in a streamed setting: The Singapore context
Authors: Liu W. C. , Wang C. K. J. , Parkins E. J.
Published: November 2005

Background. Although several studies support the existence of a negative stream effect on lower‐ability stream students' academic self‐concept, there is not enough longitudinal research evidence to preclude the possibility that the stream effect may only be temporary. In addition, not much is known about the effect of streaming on changes in students' academic self‐concept over time.

Aims. The main aims of the study were to examine the effect of streaming on (a) the students' academic self‐concept immediately after the streaming process, and at yearly intervals for 3 consecutive years, and (b) the changes in students' academic self‐concept over a 3 year period.

Sample. The sample comprised 495 Secondary 1 students (approximate age 13) from three government coeducational schools in Singapore.

Method. A longitudinal survey using a self‐reported questionnaire.

Results. Results showed that the lower‐ability stream students had a more negative academic self‐concept than the higher‐ability stream students immediately after streaming, but they had a more positive academic self‐concept 3 years after being streamed. In addition, it was established that the students' academic self‐concept declined from Secondary 1 to Secondary 3. Nonetheless, the decline was more pronounced for the higher‐ability stream students than the lower‐ability stream students.

Conclusions. Streaming may have a short‐term negative impact on lower‐ability stream students' academic self‐concept. However, in the long run, being in the lower‐ability stream may not be detrimental to their academic self‐concept.
Communication in collaborative discovery learning
Authors: Saab Nadira , van Joolingen Wouter R. , van Hout‐Wolters Bernadette H. A. M.
Published: November 2005

Background. Constructivist approaches to learning focus on learning environments in which students have the opportunity to construct knowledge themselves, and negotiate this knowledge with others. Discovery learning and collaborative learning are examples of learning contexts that cater for knowledge construction processes. We introduce a computer‐based learning environment in which the two forms of learning are implemented simultaneously. We focus on the interaction between discovery learning and collaborative learning.

Aim. We aim to investigate which communicative activities are frequently used in the discovery learning process and which communicative and discovery activities co‐occur.

Sample. The study involved 21 pairs of 10th‐grade students enrolled in pre‐university education, ranging from 15 to 17 years of age.

Method. Participants worked in dyads on separate screens in a shared discovery learning environment. They communicated using a chat box. In order to find a possible relationship between communicative activities and discovery learning processes, correlational analysis and principal component analysis were performed.

Result. Significant relationships were found between communicative and discovery activities, as well as five factors combining the communicative process and the discovery learning processes. Communicative activities are performed most frequently during the activities in generating hypotheses, experimental design, and conclusion construction. Argumentation occurs less than expected, and is associated with the construction of conclusions, rather than generating hypotheses.

Conclusion. Communicative activities co‐occur with discovery activities most of the time, as we expected. Further research should concentrate on means to augment communicative and discovery activities that are related to positive learning outcomes.
Utilization of psychotherapy in patients with personality disorder: The impact of gender, character traits, affect regulation, and quality of object‐relations
Authors: Löffler‐Stastka Henriette , Ponocny‐Seliger Elisabeth , Fischer‐Kern Melitta , Leithner Katharina
Published: November 2005

Objectives. The aim of the study was to generate hypotheses for examining gender differences in variables with predictive value for the utilization of psychotherapy in patients with personality disorders (PDs).

Design. Personality traits, affect experience and regulation, the quality of object relations and interpersonal problems within the process of psychotherapy planning were assessed in 140 psychiatric outpatients.

Methods. Besides the structured clinical interviews for DSM‐IV I+II, variables were assessed with the Shedler‐Westen assessment procedure (SWAP‐200), the affect regulation and experience Q sort (AREQ), the quality of object‐relations scale (QORS), and the Inventory of Interpersonal Problems (IIP). Correlation and group difference statistics, regression and canonical correlation analysis were performed.

Results. Predictors concerning the utilization or non‐utilization of psychotherapy were a schizoid PD rating a self‐report of subassertive behaviour related to interpersonal problems in women, and a narcissistic PD rating in men. Canonical correlations between predictors and quality of object relations or interpersonal problems were found in women, while in men there was merely a tendency for predictor and affect regulation to be related.

Conclusion . The results suggest that for men it is more important to interpret the dominating affect, while for women, understanding the pathological object relation pattern is useful for successful therapy planning.
A prospective study of the effectiveness of group and individual psychotherapy for women CSA survivors
Authors: Ryan M. , Nitsun M. , Gilbert L. , Mason H.
Published: November 2005

Objectives. There is little empirical evidence to guide clinical practice in treating adult patients presenting to adult mental health and primary care services with severe psychological difficulties consequent on childhood sexual abuse. The aim of this study was to determine the effectiveness of a model of short term, focal, integrative psychotherapy with this population of patients and to compare outcomes when the model is delivered on an individual or group basis.

Design. This study used a patient preference design with random allocation to one of two treatment modalities (individual or group treatment). There was a waiting list control.

Method. A group of 48 women patients were assessed on 4 psychological measures when entering a waiting list condition, immediately before treatment and after completion of 12 sessions of psychotherapy, either in a group or individually. Follow‐up data were collected at 4 months and 8 months.

Results. Both individual and group patients showed highly statistically and clinically significant improvements after treatment. These gains were maintained at follow‐up with the exception of one measure that indicated a significant decline from post‐treatment levels for the group patients.

Conclusions. This model of psychotherapy is highly effective, when delivered by chartered clinical psychologists to patients whose preferences for individual or group therapy have been met.
Characteristics of participants in the Forum, psychotherapy clients, and control participants: A comparative study
Authors: Rubinstein Gidi
Published: November 2005

‘New age’ activities, personality variables, symptomatology, and subjective well‐being (SWB) among the Forum (F) participants, psychotherapy (P) clients, individuals who are both Forum and psychotherapy (FP) clients, and control (C) participants, who were never involved in either F or P were compared. A group of 64 Israeli men and 76 women (mean age = 38.55 years) completed a demographic questionnaire; the Internal‐external, Sensation‐seeking, Happiness, Affects balance, Satisfaction with life, and Anxiety and depression scales of the SCL‐90. The FP and F participants used occult counsellors significantly more than the C participants, although gender differences were also found. All in all, the FP and P clients were more depressive and anxious, and less happy, less satisfied with their life, and affectively balanced than the F and the C participants. The rationality, personal responsibility, and mental health of the F participants are discussed in light of the results with considerations of short‐versus long‐term interventions.
Negotiating a pathological identity in the clinical dialogue: Discourse analysis of a family therapy
Authors: Avdi Evrinomy
Published: November 2005

Within the framework of social constructionism, psychotherapy has been re‐conceptualized as a semiotic process, which consists of the creative generation of new meanings in the context of collaborative discourse. In recent years, research approaches that draw from social constructionism, such as discourse analysis, have been fruitfully employed in the study of psychotherapy processes, whilst being in line with the contemporary emphasis on language, narrative, and meaning making. This paper aims to further the exploration of the usefulness of discourse analysis in the study of psychotherapy processes, and in particular, in situations where the medical discourse is powerfully implicated in the construction of a person's identity. It is based on the analysis of a family therapy with a family whose child has a diagnosis of autism. The analysis focuses on two features of the family's talk, namely shifts in the flexibility of employment of a diverse range of discourses and subject positions, and shifts in the ways agency is constructed and discursively negotiated in the clinical conversations. It is suggested that these shifts can be used as indications of change in the family's network of meanings. The analysis suggests that an important aspect in clinical work with families with a member with a psychiatric diagnosis lies in decentring, or deconstructing, the dominant, pathology‐maintaining accounts, and allowing for a wider range of less problematic narratives and subject positions to emerge.
Development of wet strength additives from wheat gluten
Authors: Ren Dakai , Li Kaichang
Published: November 2005

Glyoxal-polyacrylamide (GPA) resin is widely used as a wet strength additive for various paper and paperboard products. However, GPA resin is derived from petrochemicals and contributes to contaminants in the recycling of papers. Wheat gluten is one of the most abundant proteins in nature. This research investigated how to convert gliadin, a key component of wheat gluten, to an effective temporary wet-strength additive. Gliadin was first modified with glycidyltrimethylammonium chloride (GTA) to generate positively charged GTA-gliadin. Further reaction of GTA-gliadin with glyoxal yielded GTA-gliadin-glyoxal resins. Conditions for these two reactions were investigated to maximize the dry and wet strengths of GTA-gliadin-glyoxal-treated paper. At a dosage of 1 wt.%, GTA-gliadin-glyoxal resin was comparable to GPA resin in terms of enhancing the dry and wet strengths of treated paper.
Characterization of electrolyzed magnesium spent-sulfite liquor
Authors: Ringena Okko , Saake Bodo , Lehnen Ralph
Published: November 2005

Spent sulfite liquor derived from magnesium bisulfite pulping of beech was electrolyzed in a pilot-plantelectrolysis cell. During the electrochemical treatment (125 mA cm−2; 60°C; 180 min), desalination of the anolyte took place and the magnesium concentration was reduced to approximately 60%. In addition, the pH decreased from 5 to 1. Three differently treated liquors (SSL pH 5; SSLe pH 2.5; SSLe pH 1) were chosen for further analysis. The average molar mass of the fractions was determined by size exclusion chromatography. Extended electrolysis time increased the molar mass of the lignosulfonates (M
w: SSL pH 5, 5700 g mol−1; SSLe pH 2.5, 6500 g mol−1; SSLe pH 1, 7400 g mol−1). The content of phenolic hydroxyl and sulfonic acid groups did not undergo significant changes. Nevertheless, lignosulfonates obtained after electrolysis showed higher charge densities than the unmodified product (SSL pH 5, 1590 μeq g−1; SSLe pH 2.5, 1760 μeq g−1; SSLe pH 1, 1920 μeq g−1). Separation of the liquors into five fractions was performed using four ultrafiltration membranes (100, 50, 10 and 1 kDa). This allowed detailed structural analysis of high- and low-molar-mass lignosulfonate fractions in terms of the modifications induced by electrolysis.
Effect of wood species and molecular weight of phenolic resins on curing behavior and bonding development
Authors: He Guangbo , Yan Ning
Published: November 2005

In this study, dynamic mechanical analysis (DMA) was used to investigate the curing behavior and bonding performance of phenolic resins with different molecular weights as a function of three wood species. The curing process of the resin was characterized by both gel point and tanδ. The change in storage modulus before and after curing was used to characterize the bonding development. Resin molecular weight was found to significantly influence the curing process, while the effect of wood on the curing behavior among the three species was not clear. The resin should contain a low-molecular-weight fraction and a high-molecular-weight fraction to achieve the best bonding performance. The optimum molecular weight and molecular weight distribution was found to be different among the different wood species studied.
Contact-free measurement and non-linear finite element analyses of strain distribution along wood adhesive bonds
Authors: Serrano Erik , Enquist Bertil
Published: November 2005

The strain distribution along wood adhesive bonds was studied using a contact-free measurement system based on a white-light digital image correlation (DIC) technique. Two different specimen geometries and three different adhesives were investigated. The specimen geometries were according to the standards EN302-1 and ASTM D905. The adhesives tested were a phenolic resorcinol (PRF), a one-component polyurethane (PUR) and an epoxy (EPX). In addition to the experimental investigation, a finite element study using a non-linear fracture mechanics model for the adhesive bond line was carried out, aimed at investigating whether deformation measurements could predict differences in the mechanical behaviour of the adhesives. The measurement technique was found to be capable of distinguishing, in terms of their strain distributions at a given load, adhesives that differed markedly from one another. For example, the brittle PRF adhesive showed more localised strains than the more ductile EPX and PUR adhesives did at the same load level. Another conclusion from this study is that the measurement technique used is applicable to situations in which large strains occur. Thus, the technique used here is of great interest for use in the calibration of finite element models and constitutive theories and for the design of test set-ups.
Comparison between HT-dried and LT-dried spruce timber in terms of shape and dimensional stability
Authors: Kliger Robert , Bengtsson Charlotte , Johansson Marie
Published: November 2005

The performance of timber studs from Norway spruce (Picea abies) in terms of shape and dimensional stability was evaluated. The shape stability studied included three modes of distortion, i.e. twist, bow and spring. The dimensional stability was assessed by measuring longitudinal shrinkage and swelling properties. The study comprised 96 studs measuring 45 mm×70 mm×2500 mm from 15 butt logs. Half the studs from each log were dried using a high-temperature method (HT) at 115°C, while the other half were dried using a conventional low-temperature method (LT) at 70°C. Distortion in the studs was measured at moisture contents of 14% and 9%. The HT-dried timber had significantly lower distortion values than the LT-dried timber. As a result, 80% of the high-temperature-dried studs were able to pass the limits for distortion, while only 60% of the low-temperature-dried studs passed the same limit. Studs cut close to the pith displayed the largest twist, independent of the drying method. A simple model for predicting twist that was used in previous studies was also valid for HT-dried timber. The most important parameters in this model for both HT- and LT-dried timber were grain angle, annual ring curvature and tangential shrinkage.
Physical properties of earlywood and latewood of Pinus radiata D. Don: Anisotropic shrinkage, equilibrium moisture content and fibre saturation point
Authors: Pang Shusheng , Herritsch Alfred
Published: November 2005

Anisotropic shrinkage (tangential and longitudinal), equilibrium moisture content (EMC) and fibre saturation point (FSP) were measured for separated earlywood (EW) and latewood (LW) of a 0.75-m-long log of 20-year old Pinus radiata that was cut at breast height from a selected tree in the forest of Central North Island, New Zealand. The experimental results have shown that at 12% moisture content (MC), tangential shrinkage was 3.23% for EW and 3.90% for LW, with an overall average of 3.56%. Longitudinal shrinkage was 0.23% for EW and 0.21% for LW with an overall average of 0.22%. Shrinkage for the oven dry (OD) state showed similar trends to those at 12% MC in terms of the differences between EW and LW. The tangential and longitudinal shrinkage varied significantly along the radius from pith to bark. The EW tangential shrinkage increased from pith to the seventh growth ring and then remained relatively constant until the last ring adjacent to the bark. The LW tangential shrinkage also increased from the pith outwards until the seventh growth ring, but beyond that was more variable than the EW shrinkage. Both EW and LW showed similar longitudinal shrinkage, with the highest values in the second growth ring, from which the shrinkage decreased exponentially towards the bark. LW had a slightly higher EMC than EW at a relative humidity (RH) below 80%, but the trend was reversed for RH above 80%. The EMC differences between EW and LW were less than 0.6%. The overall average FSP for Pinus radiata was 29.1%, with actual values varying from 25% to 32.8%. The earlywood FSP (28.9%) was slightly lower than that of the latewood (29.4%).
Evidence for a Significant Role of α3-Containing GABAAReceptors in Mediating the Anxiolytic Effects of Benzodiazepines
Authors: Dias Rebecca , Sheppard Wayne F. A. , Fradley Rosa L. , Garrett Elizabeth M. , Stanley Joanna L. , Tye Spencer J. , Goodacre Simon , Lincoln Rachael J. , Cook Susan M. , Conley Rachel , Hallett David , Humphries Alexander C. , Thompson Sally A. , Wafford Keith A. , Street Leslie J. , Castro J. Luis , Whiting Paul J. , Rosahl Thomas W. , Atack John R. , McKernan Ruth M. , Dawson Gerard R. , Reynolds David S.
Published: November 2005

The GABAAreceptor subtypes responsible for the anxiolytic effects of nonselective benzodiazepines (BZs) such as chlordiazepoxide (CDP) and diazepam remain controversial. Hence, molecular genetic data suggest that α2-rather than α3-containing GABAAreceptors are responsible for the anxiolytic effects of diazepam, whereas the anxiogenic effects of an α3-selective inverse agonist suggest that an agonist selective for this subtype should be anxiolytic. We have extended this latter pharmacological approach to identify a compound, 4,2′-difluoro-5′-[8-fluoro-7-(1-hydroxy-1-methylethyl)imidazo[1,2-á]pyridin-3-yl]biphenyl-2-carbonitrile (TP003), that is an α3 subtype selective agonist that produced a robust anxiolytic-like effect in both rodent and non-human primate behavioral models of anxiety. Moreover, in mice containing a point mutation that renders α2-containing receptors BZ insensitive (α2H101R mice), TP003 as well as the nonselective agonist CDP retained efficacy in a stress-induced hyperthermia model. Together, these data show that potentiation of α3-containing GABAAreceptors is sufficient to produce the anxiolytic effects of BZs and that α2 potentiation may not be necessary.
Interaural Phase and Level Difference Sensitivity in Low-Frequency Neurons in the Lateral Superior Olive
Authors: Tollin Daniel J. , Yin Tom C. T.
Published: November 2005

The lateral superior olive (LSO) is believed to encode differences in sound level at the two ears, a cue for azimuthal sound location. Most high-frequency-sensitive LSO neurons are binaural, receiving inputs from both ears. An inhibitory input from the contralateral ear, via the medial nucleus of the trapezoid body (MNTB), and excitatory input from the ipsilateral ear enable level differences to be encoded. However, the classical descriptions of low-frequency-sensitive neurons report primarily monaural cells with no contralateral inhibition. Anatomical and physiological evidence, however, shows that low-frequency LSO neurons receive low-frequency inhibitory input from ipsilateral MNTB, which in turn receives excitatory input from the contralateral cochlear nucleus and low-frequency excitatory input from the ipsilateral cochlear nucleus. Therefore, these neurons would be expected to be binaural with contralateral inhibition. Here, we re-examined binaural interaction in low-frequency (less than ∼3 kHz) LSO neurons and phase locking in the MNTB. Phase locking to low-frequency tones in MNTB and ipsilaterally driven LSO neurons with frequency sensitivities <1.2 kHz was enhanced relative to the auditory nerve. Moreover, most low-frequency LSO neurons exhibited contralateral inhibition: ipsilaterally driven responses were suppressed by raising the level of the contralateral stimulus; most neurons were sensitive to interaural time delays in pure tone and noise stimuli such that inhibition was nearly maximal when the stimuli were presented to the ears in-phase. The data demonstrate that low-frequency LSO neurons of cat are not monaural and can exhibit contralateral inhibition like their high-frequency counterparts.
Neural Correlates of Fine Depth Discrimination in Monkey Inferior Temporal Cortex
Authors: Uka Takanori , Tanabe Seiji , Watanabe Masayuki , Fujita Ichiro
Published: November 2005

Binocular disparity is an important visual cue that gives rise to the perception of depth. Disparity signals are widely spread across the visual cortex, but their relative role is poorly understood. Here, we addressed the correlation between the responses of disparity-selective neurons in the occipitotemporal (ventral) visual pathway and the behavioral discrimination of stereoscopic depth. We recorded activity of disparity-selective neurons in the inferior temporal cortex (IT) while monkeys were engaged in a fine stereoscopic depth discrimination (stereoacuity) task. We found that trial-to-trial fluctuations in neuronal responses correlated with the monkey's perceptual choice. We suggest that disparity signals in the IT, located in the ventral visual pathway, are functionally linked to the discrimination of fine-grain depth.
Effect of Domain Interaction on Apolipoprotein E Levels in Mouse Brain
Authors: Ramaswamy Gayathri , Xu Qin , Huang Yadong , Weisgraber Karl H.
Published: November 2005

Apolipoprotein (apo) E4 is a risk factor for heart disease, Alzheimer's disease, and other forms of neurodegeneration, but the underlying mechanisms are unknown. Domain interaction, a structural property that distinguishes apoE4 from apoE2 and apoE3, results in more rapid turnover and lower plasma levels of apoE4. To determine whether domain interaction affects brain apoE levels, we analyzed brain homogenates from human apoE3 and apoE4 knock-in mice, wild-type mice, and Arg-61 apoE mice, in which domain interaction was introduced by gene targeting. As determined on Western blots, the hemibrain, cortex, hippocampus, and cerebellum of knock-in mice had 30-40% lower levels of apoE4 than apoE3, and Arg-61 mice had 25-50% lower apoE levels than wild-type mice. In the CSF, Arg-61 apoE level was 40% lower than the wild-type level. Arg-61 apoE mRNA levels were similar to or slightly higher than wild-type apoE mRNA levels. Thus, the lower Arg-61 apoE levels were not attributable to decreased mRNA levels. In culture medium from heterozygous Arg-61/wild-type and apoE4/apoE3 primary astrocytes, Arg-61 apoE and apoE4 levels were lower than wild-type apoE and apoE3, respectively, suggesting that primary astrocytes secrete lower amounts of Arg-61 apoE and apoE4. These results demonstrate that domain interaction is responsible for the lower levels of both human apoE4 and mouse Arg-61 apoE in mouse brain. Cells may recognize apoE4 and Arg-61 apoE as misfolded proteins and target them for degradation or accumulation. Thus, degradation/accumulation or lower levels of apoE4 may contribute to the association of apoE4 with Alzheimer's disease.
Adult-Born and Preexisting Olfactory Granule Neurons Undergo Distinct Experience-Dependent Modifications of their Olfactory ResponsesIn Vivo
Authors: Magavi Sanjay S. P. , Mitchell Bartley D. , Szentirmai Oszkar , Carter Bob S. , Macklis Jeffrey D.
Published: November 2005

Neurogenesis continues throughout adulthood in the mammalian olfactory bulb and hippocampal dentate gyrus, suggesting the hypothesis that recently generated, adult-born neurons contribute to neural plasticity and learning. To explore this hypothesis, we examined whether olfactory experience modifies the responses of adult-born neurons to odorants, using immediate early genes (IEGs) to assay the response of olfactory granule neurons. We find that, shortly after they differentiate and synaptically integrate, the population of adult-born olfactory granule neurons has a greater population IEG response to novel odors than mature, preexisting neurons. Familiarizing mice with test odors increases the response of the recently incorporated adult-born neuron population to the test odors, and this increased responsiveness is long lasting, demonstrating that the response of the adult-born neuron population is altered by experience. In contrast, familiarizing mice with test odors decreases the IEG response of developmentally generated neurons, suggesting that recently generated adult-born neurons play a distinct role in olfactory processing. The increased IEG response is stimulus specific; familiarizing mice with a set of different, “distractor” odors does not increase the adult-born neuron population response to the test odors. Odor familiarization does not influence the survival of adult-born neurons, indicating that the changes in the population response of adult-born neurons are not attributable to increased survival of odor-stimulated neurons. These results demonstrate that recently generated adult-born olfactory granule neurons and older, preexisting granule neurons undergo contrasting experience-dependent modificationsin vivoand support the hypothesis that adult-born neurons are involved in olfactory learning.
Gap Junctions Modulate Interkinetic Nuclear Movement in Retinal Progenitor Cells
Authors: Pearson Rachael A. , Lüneborg Nanna L. , Becker David L. , Mobbs Peter
Published: November 2005

During early retinal development, progenitor cells must divide repeatedly to expand the progenitor pool. During G1and G2of the cell cycle, progenitor cell nuclei migrate back-and-forth across the proliferative zone in a process termed interkinetic nuclear movement. Because division can only occur at the ventricular surface, factors that affect the speed of nuclear movement could modulate the duration of the cell cycle. Gap-junctional coupling and gap junction-dependent Ca2+activity are common features of proliferating cells in the immature nervous system. Furthermore, both gap-junctional coupling and changes in [Ca2+]ihave been shown to be positively correlated with the migration of a number of immature cell types. Using time-lapse confocal microscopy, we describe the nature and rate of progenitor cell interkinetic nuclear movement. We show that nuclear movement is usually, but not always, associated with Ca2+transients and that buffering of these transients with BAPTA slows movement. Furthermore, we show for the first time that gap-junctional communication is an important requirement for the maintenance of normal nuclear movement in retinal progenitor cells. Conventional blockers of gap junctions and transfection of cells with dominant-negative constructs of connexin 43 (Cx43) and Cx43-specific antisense oligodeoxynucleotides (asODNs) all act to slow interkinetic nuclear movement. The gap junction mimetic peptide Gap26 also acts to slow movement, an effect that we show may be attributable to the blockade of gap junction hemichannels.
A Role for Protein Phosphatases 1, 2A, and 2B in Cerebellar Long-Term Potentiation
Authors: Belmeguenai Amor , Hansel Christian
Published: November 2005

Cerebellar parallel fiber (PF)-Purkinje cell (PC) synapses can undergo postsynaptically expressed long-term depression (LTD) or long-term potentiation (LTP). PF-LTD induction requires the coactivity of the PF and CF (climbing fiber) inputs to PCs and a concomitant calcium transient and activation of protein kinase C (PKC). PF-LTP can be induced by PF activity alone and requires a lower calcium transient for its induction than PF-LTD. The cellular events triggering PF-LTP induction are not well characterized. At other types of synapses (e.g., in the hippocampus), bidirectional synaptic plasticity is under control of a kinase/phosphatase switch, with PKC and CaMKII (calcium/calmodulin-dependent kinase II) activity promoting LTP induction and phosphatase activity promoting LTD induction. Here, we have tested for the involvement of protein phosphatase 1 (PP1), PP2A, and PP2B (calcineurin) in cerebellar LTP induction using whole-cell patch-clamp recordings in rat cerebellar slices. LTP induction was blocked in the presence of the PP1/2A inhibitors okadaic acid and microcystin LR, the PP1 inhibitory peptide inhibitor-2, the PP2A inhibitor fostriecin, and the PP2B inhibitor cyclosporin A. LTP induction was not impaired by the PKC inhibitor chelerythrine. Conversely, LTD induction was not blocked by microcystin LR but instead was reduced when active PP2B was injected into PCs. These data indicate that a kinase/phosphatase switch controls bidirectional cerebellar plasticity, but in a manner “inverse” to the dependencies found at other types of synapses. Therefore, cerebellar LTP constitutes the only form of LTP described so far that depends on phosphatase rather than kinase activity.
Sexually Dimorphic Synaptic Organization of the Medial Amygdala
Authors: Cooke Bradley M. , Woolley Catherine S.
Published: November 2005

The medial amygdala is important in social behaviors, many of which differ between males and females. The posterodorsal subnucleus of the medial amygdala (MeApd) is particularly sensitive to gonadal steroid hormones and is a likely site for gonadal hormone regulation of sexually dimorphic social behavior. Here we show that the synaptic organization of the MeApd in the rat is sexually dimorphic and lateralized before puberty. With the use of whole-cell voltage-clamp recording and quantitative electron microscopy, we found that, specifically in the left hemisphere, prepubertal males have ∼80% more excitatory synapses per MeApd neuron than females. In the left but not the right MeApd, miniature EPSC (mEPSC) frequency was significantly greater in males than in females; mEPSC amplitude was not sexually dimorphic. Paired-pulse facilitation of EPSCs, an index of release probability, also was not sexually dimorphic, suggesting that greater mEPSC frequency is caused by a difference in excitatory synapse number. Electron microscopy confirmed that the asymmetric synapse-to-neuron ratio and the total asymmetric synapse number were significantly greater in the left MeApd of males than of females. In contrast to results for excitatory synapses, we found no evidence of sexual dimorphism or laterality in inhibitory synapses. Neither the frequency nor the amplitude of mIPSCs was sexually dimorphic or lateralized. Likewise, the number of symmetric synapses measured with electron microscopy was not sexually dimorphic. These findings show that the excitatory synaptic organization of the left MeApd is sexually differentiated before puberty, which could provide a sexually dimorphic neural substrate for the effects of hormones on adult social behavior.
Signal Propagation and Logic Gating in Networks of Integrate-and-Fire Neurons
Authors: Vogels Tim P. , Abbott L. F.
Published: November 2005

Transmission of signals within the brain is essential for cognitive function, but it is not clear how neural circuits support reliable and accurate signal propagation over a sufficiently large dynamic range. Two modes of propagation have been studied: synfire chains, in which synchronous activity travels through feedforward layers of a neuronal network, and the propagation of fluctuations in firing rate across these layers. In both cases, a sufficient amount of noise, which was added to previous models from an external source, had to be included to support stable propagation. Sparse, randomly connected networks of spiking model neurons can generate chaotic patterns of activity. We investigate whether this activity, which is a more realistic noise source, is sufficient to allow for signal transmission. We find that, for rate-coded signals but not for synfire chains, such networks support robust and accurate signal reproduction through up to six layers if appropriate adjustments are made in synaptic strengths. We investigate the factors affecting transmission and show that multiple signals can propagate simultaneously along different pathways. Using this feature, we show how different types of logic gates can arise within the architecture of the random network through the strengthening of specific synapses.
Charge and mass distribution in7Li induced fission of232Th
Authors: Tripathi R. , Sudarshan K. , Sodaye S. , Tomar B. S. , Gubbi G. K. , Goswami A. , Reddy A. V. R. , Manohar S. B.
Published: November 2005

Formation cross sections of about forty fission products have been determined using recoil catcher technique followed by off line gamma-ray spectrometry in7Li induced fission of232Th atElab= 41.9, 36.6 and 31.4 MeV. The measured data have been used to deduce charge and mass distributions. Mass distribution is found to be asymmetric at all the three energies. Cross sections of evaporation residues formed in both transfer reactions (232,233,234Pa) as well as in complete fusion (234Np), have also been measured. The measured evaporation residue cross sections and the decay probabilities of target like nuclei (233,234,235Pa) formed in the various transfer reactions, as calculated by PACE2, have been used to estimate the transfer induced fission cross sections. The data indicated that the magnitude of transfer induced fission is very small.
Direct evidence for enhanced inner-sphere chloro complexation of Eu(III) and Cm(III) in anion exchange resin phase studied by time-resolved laser-induced fluorescence spectroscopy
Authors: Arisaka Makoto , Kimura Takaumi , Suganuma Hideo , Yoshida Zenko
Published: November 2005

In anion exchange resin systems with LiCl-aqueous and LiCl-(H2O + CH3OH) solutions, the extent of chloro complexation of M(III) (M = Eu, Cm) was estimated from inner-sphere hydration number (N
H2O), i.e., the number of water molecules in the first coordination sphere of M(III) and from peak area ratio (A
2/A
1) of 5
D
0 → 7
F
2 transition (A
2) to 5
D
0 → 7
F
1 transition (A
1) in emission spectrum of Eu(III), which reflects the ligand environment both in the inner- and outer-spheres of Eu(III). The N
H2O of M(III) both in the solution and resin phases decreased with an increase of LiCl and CH3OH concentrations, indicating the formation of an inner-sphere M(III)-chloro complex. From the comparison of N
H2O between the both phases, it was found that the extent of the inner-sphere chloro complexation of M(III) in the resin phase is higher than that in the solution phase. The A
2/A
1 ratio in the both phases increased with an increase of interaction of Eu(III) with Cl−, which are well correlated with the results of N
H2O. The sorption equilibrium of M(III) was discussed by comparing the extent of the chloro complexation with the distribution coefficient.
Influence of aggregation on the extraction of trivalent lanthanide and actinide cations by purified Cyanex 272, Cyanex 301, and Cyanex 302
Authors: Jensen M. P. , Bond A. H.
Published: November 2005

The extraction of trivalent lanthanide (Sm3+, Eu3+) and actinide (Am3+, Cm3+) cations from 1.0 M NaNO3inton-dodecane solutions of bis(2,4,4-trimethylpentyl)phosphinic acid (HC272), bis(2,4,4-trimethylpentyl)monothiophosphinic acid (HC302), and bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HC301) is reported. In each case, the dependence of the distribution ratios on the total extractant concentration is approximately second power. Using NMR, the dimerization constant of HC301 is determined to be 0.67 ± 0.06 at 25.0 °C in deuteratedn-heptane, implying that the average aggregation of the extractant changes greatly across the extractant concentration range studied. When the effect of aggregation is considered for each of the extractants, the stoichiometries of the extracted complexes are found to be M(H(C272)2)3, M(C302)3, and M(C301)3.
Characterization of a humic gel synthesized from an activated epoxy silica gel
Authors: Barbot C. , Czerwinski K. , Buckau Gunnar , Kim J. I. , Moulin Valérie , Vial M. , Pieri J. , Durand J.-P. , Goudard F.
Published: November 2005

Purified humic acid has been covalently bound on activated epoxy silica gel particles. Determination of physical properties and chemical properties was conducted in order to characterize the material at different stages of the preparation. FTIR spectra and the PEC of the surface bound humic acid is very similar to that of humic acid starting material. This shows that the humic acid was not deteriorated during the surface binding process. This humic gel can be used as an analogue for sediment associated humic acid, with the advantage that covalently bound humic acid does not desorb, and thus allows for simple species separation between non-complexed and humic bound metal ions in batch and column experiments.
Electrochemical separation and purification of yttrium-86
Authors: Reischl G. , Rösch Frank , Machulla H.-J.
Published: November 2005

For quantitative determination of in vivo dosimetry of 90Y-labeled radiotherapeuticals by means of PET, the positron emitting analogue yttrium-86 was produced at a low energy (“medical”) cyclotron via the known 86Sr(p, n)86Y reaction. Using 200 mg of 86SrCO3 (enrichment 95.6%) and protons of 15.1 MeV energy, average yields of 86Y of 48 ± 8 MBq/µA h were produced. After dissolution of 86SrCO3 in 3 ml of 0.6 N HNO3, 86Y was deposited in a simple and highly efficient electrochemical two-step procedure onto a platinum cathode at 450 mA (= 20 mA/cm2). The isotope was finally removed from the electrode by 100–300 µl of 0.5–1.0 N HCl or 0.3–0.6 N HNO3 resulting in an overall recovery of 88 ± 6% (corrected for decay). Up to 1 GBq of 86Y with high radionuclidic and radiochemical purity were obtained after a 2.5 h irradiation and a radiochemical separation time of 2 h. An ICP/AES analysis of the separated fraction showed a very small amount of strontium (< 0.1 ppm). The chemical purity of 86Y, essential for efficient labeling, was successfully demonstrated by means of complex formation with DOTA and a DOTA-conjugated peptide, exhibiting labeling yields higher than 98%.
Analysis of Homologous Gene Clusters inCaenorhabditis elegansReveals Striking Regional Cluster Domains
Authors: Thomas James H
Published: November 2005

An algorithm for detecting local clusters of homologous genes was applied to the genome of Caenorhabditis elegans. Clusters of two or more homologous genes are abundant, totaling 1391 clusters containing 4607 genes, over one-fifth of all genes in C. elegans. Cluster genes are distributed unevenly in the genome, with the large majority located on autosomal chromosome arms, regions characterized by higher genetic recombination and more repeat sequences than autosomal centers and the X chromosome. Cluster genes are transcribed at much lower levels than average and very few have gross phenotypes as assayed by RNAi-mediated reduction of function. The molecular identity of cluster genes is unusual, with a preponderance of nematode-specific gene families that encode putative secreted and transmembrane proteins, and enrichment for genes implicated in xenobiotic detoxification and innate immunity. Gene clustering in Drosophila melanogaster is also substantial and the molecular identity of clustered genes follows a similar pattern. I hypothesize that autosomal chromosome arms in C. elegans undergo frequent local gene duplication and that these duplications support gene diversification and rapid evolution in response to environmental challenges. Although specific gene clusters have been documented in C. elegans, their abundance, genomic distribution, and unusual molecular identities were previously unrecognized.
Book reviews
Authors: Nagy B. , Kassai T.
Published: November 2005

OIE Terrestrial Animal Health Code. 13th and 14th editions (2004 and 2005) from the World Organization for Animal Health, Paris, France. 14th edition, 2005. ISBN 92-9044-635-8. Ref.: A 135; Jacques Euzéby, Gilles Bourdoiseau, Claude-Marie Chauve: Dictionnaire de parasitologie médicale et vétérinaire (Dictionary of Medical and Veterinary Parasitology). Éditions Tec & Doc - EM Inter - Lavoisier. Cachan, France, 2005. 492 pages. ISBN 2-7430-0705-2;
Increasing data security by data compression
Authors: Nemetz Tibor , Papp Pál
Published: November 2005

We analyze the effect of data-compression on security of encryption both from theoretical and practical point of view. It is demonstrated that data-compression essentially improves the security of encryption, helps to overcome technical difficulties. On the other side, it makes crypt-analysis more difficult and causes extra problems. At present data-compression applied rarely and frequently defectively. We propose a method which eliminates the negative effects. Our aim is initiate data compression as an aid for data security. To this end we provide an overview of the most frequently used cryptographic protocols. A comparison with encryption software reveals that even the most frequently used protocols do not support encryption and compression.
Burmann-series distributions and approximation operators
Authors: King J. P.
Published: November 2005

Burmann series are used to give probability distributions which generalize the known class of distributions given by power series. Positive linear operators associated with Burmann-series distribution are described. Convergence of these operators to continuous real functions is studied. Examples are discussed.
Nitrogen and phosphorus balances on Finnish dairy farms
Authors: VIRTANEN H. , NOUSIAINEN J.
Published: November 2005

The calculation of whole-farm nutrient balance is an effective and simple method for estimating the potential nutrient loading from dairy farming into the environment. In Finland, however, the published results based on larger number of farms are still lacking. In this study whole-farm nitrogen (N) and phosphorus (P) balances on Finnish dairy farms were studied based on short-cut data for the year 2002. The survey was targeted to 1260 dairy farms, located all over Finland. Of the 386 replies received, 319 were used for subsequent statistical analyses. The association between selected farm variables and nutrient balance was studied using regression analysis and a sensitivity coefficient was calculated for each regression slope. The average (± standard deviation) whole-farm nutrient balance for N and P was 109 (±41.3) and 12 (±7.2) kg ha-1, respectively. The most responsive factors affecting the nutrient balances were total nutrient and fertilizer import per ha, followed by animal density, milk export per ha and concentrate import per ha. The results suggested that nutrient surpluses could be controlled more easily in combined crop and milk than in specialised milk production. It is concluded that nutrient surplus on Finnish dairy farms is markedly lower than that on areas with intensive production in central European countries. However, when nutrient balances were extrapolated to comparable production intensity as in central Europe, the level of the surpluses was equal.;
Physical properties of synthetic bedding materials for free-stall dairy cow
Authors: RUUNANIEMI J. , HAUTALA M. , AHOKAS J.
Published: November 2005

Rest is a prerequisite for the well-being of cows and they spend 4050% of the time lying down. In this study the basic physical properties, the friction coefficient, heat flux as a function of time and softness of the bedding materials were measured. The heat flux to the bedding was shown to be large enough to affect the cows heat balance. The friction coefficients of most of the tested materials were not within the recommended 0.30.5. However, the friction values are only indicative, as the material and the shape of the arti- ficial hoof were not identical to natural hooves. There were also differences of almost an order of magnitude in the softness (Youngs modulus) of the mats. Demands for softness vary according to the type of building and cows physical condition, for instance a cow with an injured leg needs softer bedding. The properties of mats and beds varied considerably and the various properties did not correlate with each other. More information is needed concerning these values to animal welfare and health in order to be able to make recommendations of different physical material characteristics in different climate and housing conditions.;
Tungstate Treatment Improves Leydig Cell Function in Streptozotocin‐Diabetic Rats
Authors: Ballester Joan , Domínguez Jorge , Muñoz M. Carmen , Sensat Meritxell , Rigau Teresa , Guinovart Joan J. , Rodríguez‐Gil Joan E.
Published: November 2005

ABSTRACT: Oral administration of sodium tungstate to adult male streptozotocin‐diabetic rats for 3 months normalized serum levels of glucose, insulin, luteinizing hormone, and follicle‐stimulating hormone. These effects were accompanied by an increase in reproductive performance, which was related to a strong improvement in Leydig cell function markers, such as the recovery of the number of Leydig cells and serum testosterone levels. Moreover, this in vivo recovery was related to a concomitant increase in the cell expression of insulin receptors. Tungstate treatment did not modify Leydig cell function in healthy rats. Furthermore, the addition of tungstate or insulin to the mTLC‐1 cell line from Leydig cell origin increased the phosphorylation states of MAP‐kinase and glycogen synthase kinase‐3. Our results indicate that tungstate treatment in diabetic rats leads to a recovery of reproductive performance by increasing the number of Leydig cells. This increase contributes to the recovery of their functionality, thereby improving the overall function of these cells. We propose that this improvement is caused by the combined effect of the tungstate‐induced normalization of insulin glucose and luteinizing hormone serum levels and a direct action of the effector on Leydig cells through modulation of at least MAP‐kinase and glycogen synthase kinase‐3 activities.