bluuebunny/crossref_metadata_2025 huggingface dataset:
Sentence splitting and discourse structure in translations
Authors: Solfjeld Kåre
Published: April 2008

The typical informational density in German non-fictional prose often triggers sentence splitting in translations into Norwegian. Information given as VP- or NP-adjunctions in the monosentential source versions is extracted and rendered as independent sentences or conjuncts in coordinative structures in the target version. Typically, subordination in the source version signals that the information should not be seen as the main focus of the sentence. Hence, an important means of guiding the reader with regard to discourse function is lost in the translated version. This article aims at showing how certain choices of target version form can be explained by the goal of preserving the discourse structure of the original. A recurring strategy is the use of coordinated clauses or VPs in the target version. Coordination — at least in narratives licensing consequential readings between the first and second conjunct — is exploited as a device of ’downgrading’ the information of the first conjunct to a background role, preserving the second conjunct as the main focus equivalent to the original. Thus, coordination seems to compensate for the more restricted use of syntactic subordination in Norwegian.
L1 effects on the emergence of ESL sentence processing skills of Chinese and Korean ESL learners
Authors: Fender Michael
Published: April 2008

This study examines the emergence of lower-level ESL sentence processing skills involved in integrating English words into predicate structures on-line. The aim of the present study is to examine how the L1 phrase structure and corresponding L1 word integration skills of ESL learners influence their corresponding ESL sentence processing skills in an on-line English sentence reading task. The study examined the English predicate and verb phrase processing skills of a group of Chinese ESL learners whose language has right-branching L1 verb phrase structures (head-complement word order) and a group of proficiency-matched Korean ESL learners whose native language only allows left-branching L1 verb phrase structures (i.e., complement-head word order). The Chinese ESL group (n = 20) was significantly faster than the Korean ESL group (n = 18) in reading and integrating direct object nouns into English predicate phrase structures, though there were no significant differences comprehending the sentences. In addition, the Chinese ESL group was significantly more accurate in reading and comprehending transitive sentences in which the direct objects had an embedded relative clause. The results suggest that L1 word integration skills influence and shape the emergence of on-line ESL word integration
Effects of hook size and barbless hooks on hooking injury, catch per unit effort, and fish size in a mixed-species recreational fishery in the western Mediterranean Sea
Authors: Alós Josep , Palmer Miquel , Grau Antoni Maria , Deudero Salud
Published: April 2008

Alós, J., Palmer, M., Grau, A. M., and Deudero, S. 2008. Effects of hook size and barbless hooks on hooking injury, catch per unit effort, and fish size in a mixed-species recreational fishery in the western Mediterranean Sea. – ICES Journal of Marine Science, 65: 899–905. The effects of hook size (small vs. large) and type (conventional vs. barbless) on hooking injury, catch per unit effort (cpue), and fish size in a mixed-species recreational fishery in the Balearic Islands (western Mediterranean) are evaluated. Hook size was the most important predictor of deep-hooking, which is reduced by the use of large hooks. The size of fish captured was another predictor of deep-hooking incidence, because large fish tended to be caught in deep-hooking locations. Deep-hooking was highly correlated with the presence of bleeding, and unhooking time was reduced by the use of large hooks and barbless hooks, although differences were small. To determine the effects of different hook treatments on cpue and species composition, a mixed-effect linear model was used as a univariate procedure, and redundancy analysis was used as a multivariate analysis. Results showed a drastic decrease in cpue with barbless hooks. In contrast, large hooks reduced the incidence of hooking injuries, with a small reduction in catch rate. Moreover, large hooks were associated with a larger mean size of fish caught than small hooks. Hence, control of hook size, along with other traditional management measures that involve the release of fish, is presented as a management option for sustainable development of recreational fisheries in the western Mediterranean Sea.
Pavlovian influences on goal-directed behavior in mice: The role of cue-reinforcer relations
Authors: Crombag Hans S. , Galarce Ezequiel M. , Holland Peter C.
Published: April 2008

Two experiments refined procedures to study Pavlovian influences on goal-directed behavior in mice and studied the effects of CS–US relations in Pavlovian-instrumental interactions. Independent groups of mice underwent Pavlovian training to associate either a 10-sec or 2-min auditory stimulus (CS) with reward. We next assessed the ability of the response-contingent CS presentations to reinforce novel instrumental responding (conditioned reinforcement; CRf) or the ability of noncontingent CS presentations to increase ongoing instrumental responding (Pavlovian-instrumental transfer; PIT). Whereas 10-sec training conditions produced strong CRf (and no PIT), 2-min training conditions produced robust PIT (but no CRf).
Sleep in children improves memory performance on declarative but not procedural tasks
Authors: Wilhelm Ines , Diekelmann Susanne , Born Jan
Published: April 2008

Sleep supports the consolidation of memory in adults. Childhood is a period hallmarked by huge demands of brain plasticity as well as great amounts of efficient sleep. Whether sleep supports memory consolidation in children as in adults is unclear. We compared effects of nocturnal sleep (versus daytime wakefulness) on consolidation of declarative (word-pair associates, two-dimensional [2D] object location), and procedural memories (finger sequence tapping) in 15 children (6–8 yr) and 15 adults. Beneficial effects of sleep on retention of declarative memories were comparable in children and adults. However, opposite to adults, children showed smaller improvement in finger-tapping skill across retention sleep than wakefulness, indicating that sleep-dependent procedural memory consolidation depends on developmental stage.
Selective and protracted effect of nifedipine on fear memory extinction correlates with induced stress response
Authors: Waltereit Robert , Mannhardt Sönke , Nescholta Sabine , Maser-Gluth Christiane , Bartsch Dusan
Published: April 2008

Memory extinction, defined as a decrease of a conditioned response as a function of a non-reinforced conditioned stimulus presentation, has high biological and clinical relevance. Extinction is not a passive reversing or erasing of the plasticity associated with acquisition, but a novel, active learning process. Nifedipine blocks L-type voltage gated calcium channels (LVGCC) and has been shown previously to selectively interfere with the extinction, but not the acquisition, of fear memory. We studied here the effect of retrograde and anterograde shifts of nifedipine application, with respect to an extinction training, on the extinction of fear conditioning. Subcutaneous injection of 30 mg/kg nifedipine, at least up to 4 h before the extinction session, significantly impaired extinction, as did intraperitoneal injection of 15 mg/kg nifedipine, at least up to 2 h before extinction training. However, the injection of nifedipine also induced a strong and protracted stress response. The pharmacokinetics of nifedipine suggest that it was mainly this stress response that triggered the specific inhibition of extinction, not the blockade of LVGCC in the brain. Our results support recent findings that stress selectively interferes with the extinction, but not the acquisition, of fear memory. They also indicate that a pharmacological approach is not sufficient to study the role of brain LVGCC in learning and memory. Further research using specific genetically modified animals is necessary to delineate the role of LVGCC in fear memory extinction.
β-Adrenergic receptor activation during distinct patterns of stimulation critically modulates the PKA-dependence of LTP in the mouse hippocampus
Authors: Gelinas Jennifer N. , Tenorio Gustavo , Lemon Neal , Abel Ted , Nguyen Peter V.
Published: April 2008

Activation of β-adrenergic receptors (β-ARs) enhances hippocampal memory consolidation and long-term potentiation (LTP), a likely mechanism for memory storage. One signaling pathway linked to β-AR activation is the cAMP-PKA pathway. PKA is critical for the consolidation of hippocampal long-term memory and for the expression of some forms of long-lasting hippocampal LTP. How does β-AR activation affect the PKA-dependence, and persistence, of LTP elicited by distinct stimulation frequencies? Here, we use in vitro electrophysiology to show that patterns of stimulation determine the temporal phase of LTP affected by β-AR activation. In addition, only specific patterns of stimulation recruit PKA-dependent LTP following β-AR activation. Impairments of PKA-dependent LTP maintenance generated by pharmacologic or genetic deficiency of PKA activity are also abolished by concurrent activation of β-ARs. Taken together, our data show that, depending on patterns of synaptic stimulation, activation of β-ARs can gate the PKA-dependence and persistence of synaptic plasticity. We suggest that this may allow neuromodulatory receptors to fine-tune neural information processing to meet the demands imposed by numerous synaptic activity profiles. This is a form of “metaplasticity” that could control the efficacy of consolidation of hippocampal long-term memories.
Proteasome inhibition enhances the induction and impairs the maintenance of late-phase long-term potentiation
Authors: Dong Chenghai , Upadhya Sudarshan C. , Ding Lan , Smith Thuy K. , Hegde Ashok N.
Published: April 2008

Protein degradation by the ubiquitin–proteasome pathway plays important roles in synaptic plasticity, but the molecular mechanisms by which proteolysis regulates synaptic strength are not well understood. We investigated the role of the proteasome in hippocampal late-phase long-term potentiation (L-LTP), a model for enduring synaptic plasticity. We show here that inhibition of the proteasome enhances the induction of L-LTP, but inhibits its maintenance. Proteasome inhibitor-mediated enhancement of the early part of L-LTP requires activation of NMDA receptors and the cAMP-dependent protein kinase. Augmentation of L-LTP induction by proteasome inhibition is blocked by a protein synthesis inhibitor anisomycin and is sensitive to the drug rapamycin. Our findings indicate that proteasome inhibition increases the induction of L-LTP by stabilizing locally translated proteins in dendrites. In addition, our data show that inhibition of the proteasome blocks transcription of brain-derived neurotrophic factor (BDNF), which is a cAMP-responsive element-binding protein (CREB)-inducible gene. Furthermore, our results demonstrate that the proteasome inhibitors block degradation of ATF4, a CREB repressor. Thus, proteasome inhibition appears to hinder CREB-mediated transcription. Our results indicate that blockade of proteasome activity obstructs the maintenance of L-LTP by interfering with transcription as well as translation required to sustain L-LTP. Thus, proteasome-mediated proteolysis has different roles during the induction and the maintenance of L-LTP.
Children’s Strategies for Agency in Preschool
Authors: Markström Ann‐Marie , Halldén Gunilla
Published: April 2008

This article is based on an ethnographic study of children’s everyday life in Swedish preschools. The ethnography is used to explore children’s strategies for influencing, defending and constructing the social order of a preschool institution. The focus of our concern is on how the children, in their interactions with each other and with the preschool teachers, manage the collective regulation and how they negotiate their participation in collective activities. There is an inherent tension between free play and the high degree of routinised and collective activities within the preschool institution. The study shows that children are active in playing at the border, acting as if the institution is the children’s place. It also shows how they draw on different strategies as resources for managing the regulations, accounting for personal autonomy and negotiating the social order. In taking a child perspective and acknowledging children as active agents, it is possible to see how they influence and shape their everyday life in a preschool context. In addition, the article illustrates individual children’s strategic and pragmatic use of resources and in doing so contribute to their own childhood and thereby become part of a social and cultural construction process.
What is Important to Young Children Who Have Cancer While in Hospital?
Authors: Aldiss Susie , Horstman Maire , O’Leary Chris , Richardson Alison , Gibson Faith
Published: April 2008

This paper reports on a participatory research project exploring children’s experiences and views of cancer care services. It focusses on findings from interviews conducted with 10 children aged four and five years old. Play and puppets were used to help children express their views. The themes elicited reveal important aspects of hospital care for young children, such as having ‘lots of toys’ available and that ‘mummy and daddy are near’. The use of play and puppets as a data‐collection method is discussed, along with the implications of findings for the care and support of young children who have cancer.
Young Peoples’ Representations of ‘Atypical’ Work in English Society
Authors: Crafter Sarah , O’Dell Lindsay , De Abreu Guida , Cline Tony
Published: April 2008

In this paper, we explore young peoples’ normative representations of work. In particular, we are interested in the ways young people view work roles which could be considered ‘atypical’ such as young caring or language brokering. Interviewed were 46 young people (15–18 years) some who did, and some who did not engage in the ‘atypical’ work roles of language brokering or young caring. Findings indicated that young people have a strong representation of what a ‘normal’ childhood comprises and that friends, teachers and parents play a mediational role in cementing this contextually. However, respondents presented two alternative representations around engagement in ‘atypical’ roles, with some individuals holding both views at the same time. On the one hand, they felt that engagement in ‘atypical’ activities would be experienced as a loss of ‘normal’ childhood. On the other hand, a more positive representation of ‘atypical’ childhoods was also drawn on, in which engagement in ‘atypical’ activities was seen as a source of pride and a contributor of additional skills to a child’s development. This opinion was evidenced by both those who had, and those who had not engaged in ‘atypical’ work.
Adherence to statin or aspirin or both in patients with established cardiovascular disease: exploring healthy behaviour vs. drug effects and 10‐year follow‐up of outcome
Authors: Wei Li , Fahey Tom , MacDonald Thomas M.
Published: April 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Aspirin and statins are widely‐used drugs in patients with cardiovascular disease.

• There is less information on healthy behaviour vs. drug effects.

WHAT THIS STUDY ADDS

• Long‐term adherence to aspirin and statin treatments in patients with established cardiovascular disease has been investigated.

• Poor health behaviour is not a sufficient explanation of adverse outcome in poorly adherent patients.

Aims

To characterize adherence in patients with established cardiovascular disease taking statins and aspirin and to estimate the effects of adherence due to health behaviour, a lack of beneficial drug effect, or both on recurrence of cardiovascular disease or all‐cause mortality over 10 years.

Methods

A population‐based cohort study using a record‐linkage database in Tayside, Scotland. Subjects with cardiovascular disease (n = 7657; 4185 aspirin‐alone cohort, 671 statin‐alone cohort and 2801 combination use cohort) were studied between 1993 and 2003. The effects of adherence on recurrence of cardiovascular disease or mortality were assessed using Poisson regression model.

Results

In subjects taking both aspirin and statins, those adherent to statins but not aspirin had a lower risk of recurrence [adjusted risk ratio (RR) 0.64; 95% confidence interval 0.49, 0.82], but those adherent to aspirin but not statins has no such effect (adjusted RR 0.91; 0.72, 1.15), suggesting that adherence behaviour alone was not responsible for the beneficial effect. Within the group adherent to aspirin, ≥80% adherence to statins was associated with reduced recurrence compared with those poorly adherent (adjusted RR 0.76; 0.62, 0.94), but no such effect of aspirin was seen in those adherent to statins. Similar results were found for all‐cause mortality.

Conclusions

Poor health behaviour is not a sufficient explanation of adverse outcome in poorly adherent patients. Adverse outcome is more likely to be driven by foregone drug benefits.
A pharmacokinetic study of etravirine (TMC125) co‐administered with ranitidine and omeprazole in HIV–negative volunteers
Authors: Schöller‐Gyüre Monika , Kakuda Thomas N. , De Smedt Goedele , Vanaken Hilde , Bouche Marie‐Paule , Peeters Monika , Woodfall Brian , Hoetelmans Richard M. W.
Published: April 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Drug–drug interactions with acid‐suppressing agents were previously described with several other antiretroviral drugs.

• Etravirine (TMC125) is a next‐generation non‐nucleoside reverse transcriptase inhibitor, metabolized by CYP3A and CYP2C enzymes with demonstrated efficacy in treatment‐experienced HIV‐infected patients.

• The effect of acid‐suppressing agents on the pharmacokinetics of etravirine was unknown.

WHAT THIS STUDY ADDS

• No clinically relevant effect was shown on the pharmacokinetics of etravirine when co‐administered with ranitidine or omeprazole, drugs that increase gastric pH.

• A drug–drug interaction due to CYP2C19 inhibition by omeprazole has been identified.

• Etravirine can be co‐administered with proton pump inhibitors and H2 antagonists without dose adjustments.

Aims

Etravirine is a next‐generation non‐nucleoside reverse transcriptase inhibitor (NNRTI) with activity against wild‐type and NNRTI‐resistant HIV. Proton pump inhibitors and H2‐antagonists are frequently used in the HIV‐negative‐infected population, and drug–drug interactions have been described with other antiretrovirals. This study evaluated the effect of steady‐state omeprazole and ranitidine on the pharmacokinetics of a single dose of etravirine.

Methods

In an open‐label, randomized, one‐way, three‐period crossover trial, HIV‐negative volunteers randomly received a single dose of 100 mg etravirine alone (treatment A); 11 days of 150 mg ranitidine b.i.d. (treatment B); and 11 days of 40 mg omeprazole q.d. (treatment C). A single dose of 100 mg etravirine was co‐administered on day 8 of sessions 2 and 3. Each session was separated by a 14‐day wash‐out.

Results

Nineteen volunteers (seven female) participated. When a single dose of etravirine was administered in the presence of steady‐state ranitidine, etravirine least squares means ratios (90% confidence interval) for AUClast and Cmax were 0.86 (0.76, 0.97) and 0.94 (0.75, 1.17), respectively, compared with administration of etravirine alone. When administered with steady‐state omeprazole, these values were 1.41 (1.22, 1.62) and 1.17 (0.96, 1.43), respectively. Co‐administration of a single dose of etravirine and ranitidine or omeprazole was generally safe and well tolerated.

Conclusions

Ranitidine slightly decreased etravirine exposure, whereas omeprazole increased it by approximately 41%. The increased exposure of etravirine when co‐administered with omeprazole is attributed to CYP2C19 inhibition. Considering the favourable safety profile of etravirine, these changes are not clinically relevant. Etravirine can be co‐administered with proton pump inhibitors and H2 antagonists without dose adjustments.
Refugia in the Cordilleran ice sheet of western North America: chloroplast DNA diversity in the Arctic–alpine plant Oxyria digyna
Authors: Marr Kendrick L. , Allen Geraldine A. , Hebda Richard J.
Published: April 2008

Aim  Late Pleistocene ice sheets are thought to have covered most of western Canada, including all of British Columbia (BC). We examine patterns of genetic variation in an Arctic–alpine plant to evaluate the possibility of full glacial refugia within the area covered by the Cordilleran ice sheet (CIS) and to uncover post‐glacial migration routes.

Location  Western North America.

Methods  We sampled 1030 individuals of the Arctic–alpine plant Oxyria digyna from 117 populations distributed over much of its range in western and northern North America. DNA haplotypes were identified using restriction site analysis of two chloroplast DNA intergene spacer regions, psbA‐trnH and trnT‐L. We examined the geographical distribution of haplotype diversity in relation to latitude, and also compared various indices of diversity in putatively glaciated and unglaciated regions. Patterns of migration were inferred using nested clade analysis.

Results  We detected a total of 20 haplotypes. High haplotype diversity was found in Beringia, in unglaciated western USA, and in northern BC at 57–59° N, well within the accepted limits of the CIS. Ancestral haplotypes were also centred in northern BC.

Main conclusions  High genetic diversity of Oxyria digyna is expected in unglaciated regions, but unexpected in northern BC if British Columbia was entirely covered by ice during the late Pleistocene. Our observations suggest the presence of unglaciated areas providing late Pleistocene refugia in northern BC. Such refugia would have important implications for the origins and migrations of many plant and animal species in north‐western North America.
ORIGINAL ARTICLE: Colonization and diversification in the African ‘sky islands’ by Eurasian Lychnis L. (Caryophyllaceae)
Authors: Popp Magnus , Gizaw Abel , Nemomissa Sileshi , Suda Jan , Brochmann Christian
Published: April 2008

Aim  Many plants occurring on the isolated mountain peaks of Africa have their closest relatives in very remote areas, even in temperate Europe and Asia. Their biogeographical history is poorly understood. The Afro‐montane element of the primarily Eurasian genus Lychnis is a typical example of such a disjunction. Here, we aim to reconstruct the phylogeny of the Afro‐montane endemics of Lychnis and to infer the history of immigration into Africa and of the subsequent dispersal and speciation.

Location  The Afro‐montane representatives of Lychnis occur in Ethiopia, Kenya, Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of Congo, Cameroon, and Nigeria.

Methods  Silica‐dried plant materials collected in Ethiopia in 2004 as well as herbarium material were used for DNA extractions. We used parsimony analysis of nucleotide data from the rps16 intron and psbE‐petL region in plastids, and the internal transcribed spacer (ITS) and a region spanning exon 18–24 in the second largest subunit of RNA polymerase II (RPB2) from the nucleus. DAPI‐flow cytometry was used to determine relative genome size and to infer polyploidization events.

Results  Monophyly of the Afro‐montane Lychnis with the Eurasian diploid L. flos‐cuculi resolved as sister was strongly supported by the phylogenetic analyses. The Afro‐montane group was further divided into two strongly supported groups correlated with DNA ploidy levels. The relative genome size was species‐specific except for L. abyssinica, which had two genome‐size variants.

Main conclusions  Our results demonstrate that the biogeographical history of the Afro‐montane Lychnis has been highly dynamic, including polyploidization and both old and recent long‐distance dispersal events, even between Eastern and West Africa. The ancestor is inferred to have immigrated once from Eurasia via the Arabian Peninsula to the Ethiopian highlands. Divergence in the lineage containing diploid taxa was followed by several dispersals from Ethiopia to the Eastern and Western Rift Mountains, and recently to West Africa. Divergence of the lineage including the tetraploid L. crassifolia may have taken place in Ethiopia, from where it dispersed to the Eastern and Western Rift Mountains; alternatively, it may have taken place in the Eastern Rift Mountains, followed by dispersal from there to the Western Rift Mountains and then to Ethiopia.
Climate‐driven range dynamics of the freshwater limpet, Ancylus fluviatilis (Pulmonata, Basommatophora)
Authors: Cordellier Mathilde , Pfenninger Markus
Published: April 2008

Aim  Our aim was to understand the processes that have shaped the present‐day distribution of the freshwater limpet Ancylus fluviatilis sensu stricto in order to predict the consequences of global climate change for the geographical range of this species.

Location  North‐western Europe.

Methods  We sampled populations of A. fluviatilis sensu stricto over the entire range of the species (north‐western Europe) and sequenced 16S ribosomal RNA (16S) and cytochrome oxidase subunit I (COI) mitochondrial fragments to perform phylogenetic and phylogeographical analyses. Climatic niche modelling allowed us to infer the climatic preferences of the species. A principal components analysis identified the most important climatic factors explaining the actual range of A. fluviatilis. We also identified which climatic factor was the most limiting at range margins, and predicted the species’ geographical range under a climate change scenario [Community Climate Model 3 (CCM3)].

Results  By means of the phylogeographical analysis, we infer that A. fluviatilis sensu stricto occupied northern refuges during the Last Glacial Maximum. We show that the climatic preferences of Baltic populations are significantly different from those of Central European populations. The projection of the occupied area under the CCM3 climate model predicts a moderate poleward shift of the northern range limits, but a dramatic loss of areas currently occupied, for instance in northern Germany and in southern Great Britain.

Main conclusions  The post‐glacial range dynamics of A. fluviatilis are not governed by niche conservatism. Therefore, we must be cautious about bioclimatic model predictions: the expected impact of climate change could be tempered by the adaptive potential this species has already shown in its evolutionary history. Thus, modelling approaches should rather be seen as conservative forecasts of altered species ranges as long as the adaptive potential of the organisms in question cannot be predicted.
Vegetation, climate and palaeoaltitude reconstructions of the Eastern Alps during the Miocene based on pollen records from Austria, Central Europe
Authors: Jiménez‐Moreno Gonzalo , Fauquette Séverine , Suc Jean‐Pierre
Published: April 2008

Aim To reconstruct the flora, vegetation, climate and palaeoaltitude during the Miocene (23.03–5.33 Ma) in Central Europe.

Location Six outcrop sections located in different basins of the Central Paratethys in Austria.

Methods Pollen analysis was used for the reconstruction of the vegetation and climate. The altitude of the Eastern Alps that are adjacent to the Alpine Foreland and Vienna basins has been estimated using a new quantification method based on pollen data. This method uses biogeographical and climatological criteria such as the composition of the modern vegetation belts in the European mountains and Miocene annual temperature estimates obtained from fossil pollen data.

Results Pollen changes from Early to Late Miocene have been observed. The vegetation during the Burdigalian and Langhian (20.43–13.65 Ma) was dominated by thermophilous elements such as evergreen trees, typical of a present‐day evergreen rain forest at low altitudes (i.e. south‐eastern China). During the Serravallian and Tortonian (13.65–7.25 Ma) several thermophilous elements strongly decreased, and some disappeared from the Central European region. This kind of vegetation was progressively substituted by one enriched in deciduous and mesothermic plants. Middle‐altitude (Cathaya,CedrusandTsuga) and high‐altitude (AbiesandPicea) conifers increased considerably during the Langhian and later on during the Serravallian and Tortonian.

Main conclusions Pollen changes are related to climatic changes and to the uplift of the Alpine massifs. The vegetation during the Burdigalian and Langhian reflects the Miocene climatic optimum. The decrease in thermophilous plants during the Serravallian and Tortonian can be interpreted as a climatic cooling and can be correlated with global and regional climatic changes. This study shows that the palaeoaltitude of the eastern part of the Eastern Alps during the Burdigalian was not high enough forAbiesandPiceato form a forest. Therefore, we inferred that the summits of most of the mountains would have been less than 1800 m. The substantial increase of middle‐ and high‐altitude conifers in the pollen spectra suggests that the uplift rate increased during the Langhian in this region. Based on higher palaeoaltitude estimations for the pollen floras from the studied sections of Austria, we infer that the uplift of the easternmost part of the Alpine chain continued during the Serravallian and Tortonian.
Compression and crevasses in vitreous sections under different cutting conditions
Authors: HAN H.‐M. , ZUBER B. , DUBOCHET J.
Published: April 2008

Compression and crevasses are common cutting artefacts in cryo‐ultramicrotomy of vitreous sections. They can be reduced or suppressed under optimal cutting conditions. In the present study, compression and thickness were measured for different cutting speeds and knife angles. It was found that compression decreased with feed and that crevasses appeared only above a certain thickness. The optimal feed for vitreous sections was between 50 and 80 nm. The thickness, calculated by two independent methods, was quantitatively related to feed and compression.
Selective detection of luminescence from semiconductor quantum dots by nanosecond time‐gated imaging with a colour‐masked CCD detector
Authors: MITCHELL A. C. , DAD S. , MORGAN C. G.
Published: April 2008

Quantum dots are of considerable interest as highly detectable labels with broad absorption, narrow spectral emission and good quantum yields. The luminescence emission has a longer decay time than that of the most common fluorophores, leading to facile rejection of much background emission (such as autofluorescence from biological samples) by means of gated detection. Here, it is shown that a new technique, true‐colour nanosecond time‐gated luminescence imaging, can be used for selective detection of quantum dot luminescence and should prove valuable for multiplexed detection on the basis of both spectral emission profile and luminescence decay time.
Single wavelength micro‐endoscopy in non‐surgical vascular lesion diagnosis & characterization
Authors: PAPAGATSIA Z. , TAPPUNI A. , WATSON T. F. , COOK R. J.
Published: April 2008

Malignant and dysplastic epithelial lesions have often been reported to excite vascular responses by histopathological characterization. Little is reported concerning in vivo real‐time imaging of vascular patterns and flow in health or disease but the development of miniature imaging instrumentation has now allowed such developments.

We describe the application of a selective wavelength (540 nm) epi‐illumination Hopkins pattern endoscopic imaging system to image vascular tissues and capillary blood flow in vivo. The contrast mechanism in such imaging was characterized, haemoglobin acting as a chromatic transmission filter despite endoscopy being a non‐invasive and therefore principally reflection mode imaging system. In vivo adrenergic vascular responses, capillary flow rate variations over time and variations in normal capillary architecture around the oral cavity were recorded; demonstrating that simple imaging systems can be used for non‐surgical diagnosis and characterization of vascular lesions, tumours and treatment responses.
AFM for diagnosis of nanocrystallization of steels in hardening processes
Authors: POMPEO G. , GIRASOLE M. , LONGO G. , CRICENTI A. , BAILO D. , RONCI F. , MARAS A. , SERRACINO M. , MORETTI P. F.
Published: April 2008

Introduction: The aim of this study is to investigate the nanocrystallization of steels caused by the transformation from the austenitic to the martensitic phase induced by a severe plastic deformation (SPD) treatment. In this framework, we applied an air blast shot peening treatment, which is a simple protocol widely used for industrial purposes.

Methods: AISI 286 and AISI 316 specimens were peened for different times and polished using diamond pastes in order to remove corrugations higher than 1 μm. The characterization of the steel surfaces was performed by atomic force microscopy (AFM) operating in contact mode. Additional EDXD measurements were performed to confirm the phase transition.

Results and Discussion: An AFM‐based characterization at nanometric level of the steel surfaces is provided. When the peening exceeds a threshold time that, as expected, depends on the steel composition, a uniform nanostructuration is detected. It is well known that such rearrangement is associated to the growth of a martensitic phase. To date, AFM has been employed in this field only for few applications and to solve specific problems. On the other hand, our results demonstrate that this is a useful technique for the characterization of hardened surfaces, especially when non‐destructive sample preparation treatments are required. Moreover, we show that AFM can be a useful tool also for in situ industrial diagnostics of metallic parts.
Comparative study using scanning electron techniques for imaging of micro‐architecture and antigen appearance
Authors: SOCHER R. , BENAYAHU D.
Published: April 2008

We have used various scanning electron microscopy technologies for the analysis of structures and the appearance of antigen on eukaryotic cells. Various scanning electron microscopy including conventional scanning electron microscopy, high‐resolution scanning electron microscopy and environmental scanning electron microscopy applied for cell surface analysis allow obtaining sub‐micrometre surface features on cell membranes. We used cell systems for imaging along with molecular localization of a cell surface antigen, SVEP1 protein. SVEP1 was studied using the immuno‐gold technique for the identification of cell surface features and protein localization. We used an antibody to SVEP1 molecule that was labelled with secondary antibody conjugated with gold particles. The comparison between scanning electron methods enabled the visualization of surface structures and the molecular imaging for the distribution of SVEP1.
Silver enhancement of Nanogold particles during freeze substitution for electron microscopy
Authors: MORPHEW M. , HE W. , BJORKMAN P. J. , McINTOSH J. RICHARD
Published: April 2008

Recent advances in rapid freezing and fixation by freeze substitution have allowed structural cell biologists to apply these reliable modes of sample preparation to a wide range of specimens and scientific problems. Progress in electron tomography has produced cellular images with resolution approaching 4 nm in 3D, but our ability to localize macromolecules in these well‐fixed, well‐resolved samples has remained limited. When light fixation and low temperature embedding are employed with appropriate resins, immuno‐localizations can recognize antigens at a section's surface, but labelling is therefore confined, not throughout the section's depth. Small, electron‐dense markers, like Nanogold®, will often enter a living cell, serving as reliable tracers for endocytic activity, but these markers are usually too small to be visible in the context of a cell. We have developed a method for the silver enhancement of Nanogold particles that works during freeze substitution in organic solvents at low temperature. Here, we describe the development of this method, based on in vitro tests of reagents and conditions. We then show results from application of the method to an in vivo system, using Nanogold to track the internalization of immunoglobulin by neonatal murine intestinal epithelium, a specific example of receptor‐mediated membrane traffic.
Golgi apparatus studied in vitreous sections
Authors: BOUCHET‐MARQUIS C. , STARKUVIENE V. , GRABENBAUER M.
Published: April 2008

Cryo‐electron microscopy of vitrified specimen is the method of choice to explore cellular ultrastructure at high resolution as close as possible to the native state and environment. In this study, we investigated the Golgi apparatus – the main organelle of the secretory pathway. Cultured mammalian cells were fixed by high‐pressure freezing, sectioned in vitreous ice and subjected to cryo‐electron microscopy and cryo‐electron tomography. Although the overall morphology of Golgi stacks was comparable to well prepared and plastic‐embedded samples, in detail we reached much higher resolution in terms of distinction between biological structures based on their native density. On cisternal buds and peri‐Golgi vesicles – some associated with microtubules – we detected two different subtypes of COPI coats: (1) a homogenous coat and (2) an inhomogeneous spiky coat, providing an 8–9 nm regularity, clearly distinct from clathrin coat. Next, we monitored the secretion of cargo, namely, procollagen I, through the Golgi complex. Temporally correlated with fluorescence microscopy, we performed three‐dimensional cryo‐electron tomography analysis and detected Golgi cisternae enlarged to saccules, containing cargo and showing inter‐cisternal connections. Our work provides a first step towards the high‐resolution description of the secretory pathway in native vitrified samples and describes the challenges associated with this attempt.
Moving EM: the Rapid Transfer System as a new tool for correlative light and electron microscopy and high throughput for high‐pressure freezing
Authors: VERKADE P.
Published: April 2008

In this paper, the Rapid Transfer System (RTS), an attachment to the Leica EMPACT2 high‐pressure freezer, is described as a new tool for special applications within the cryofixation field. The RTS is an automated system that allows for fast processing of samples (<5 s) that make it possible for the first time to use high‐pressure freezing in combination with high time resolution correlative light and electron microscopy. In addition, with a working cycle of 30 s this rapid turn over time allows one to acquire more samples of biopsy material before it deteriorates than with other HPF machines with longer cycle times. With the use of the RTS it was possible to obtain three samples each of four different tissues in 6 min. Together with the finding that 90% of samples of cells grown on sapphire discs were well frozen, the RTS was both fast and reliable. Most important, together with other newly developed accessories, the RTS made it possible to capture specific events occurring live in the cell as observed by light microscopy, to cryofix that sample/event within 4 s, and then to analyze that event at high resolution in the electron microscope with excellent preservation of ultra‐structure. These developments should give us the tools to unravel intracellular processes that can be observed by live cell imaging but are too rare or fast to be picked up by routine EM methods or where the history of a structure is necessary to be able to discern its nature.
Cryptic speciation in a Holarctic passerine revealed by genetic and bioacoustic analyses
Authors: TOEWS DAVID P. L. , IRWIN DARREN E.
Published: April 2008

There has been much controversy regarding the timing of speciation events in birds, and regarding the relative roles of natural and sexual selection in promoting speciation. Here, we investigate these issues using winter wrens (Troglodytes troglodytes), an unusual example of a passerine with a Holarctic distribution. Geographical variation has led to speculation that the western North American formTroglodytes troglodytes pacificusmight be a distinct biological species compared to those in eastern North America (e.g.Troglodytes troglodytes hiemalis) and Eurasia. We located the first known area in which both forms can be found, often inhabiting neighbouring territories. Each male wren in this area sings either western or eastern song, and the differences in song are as distinct in the contact zone as they are in allopatry. The two singing types differ distinctly in mitochondrial DNA sequences and amplified fragment length polymorpism profiles. These results indicate that the two forms are reproductively isolated to a high degree where they co‐occur and are therefore separate species. DNA variation suggests that the initial split between the two species occurred before the Pleistocene, quite long ago for sister species in the boreal forest. Surprisingly, the two forms are similar in morphometric traits and habitat characteristics of territories. These findings suggest that sexual selection played a larger role than habitat divergence in generating reproductive isolation, and raise the possibility that there are other such morphologically cryptic species pairs in North America.
Outcrossing between an agroforestry plantation and remnant native populations of Eucalyptus loxophleba
Authors: SAMPSON JANE F. , BYRNE MARGARET
Published: April 2008

Gene dispersal among populations of a species is an important force influencing their genetic structure. Dispersal may also occur between taxa that would normally be isolated when nonendemic, domesticated or transgenic species are planted within the natural range of interfertile taxa. Such a mosaic of populations is typical of many agricultural landscapes, and investigations are needed to assess the risks of genetic contamination of the endemic populations but a combination of approaches may be necessary because of the limitations of research in this landscape. This study used microsatellite markers and a range of analyses (mating system, paternity exclusion, Bayesian assignment) to examine gene dispersal between remnants of the endemic Eucalyptus loxophleba ssp. supralaevis and a plantation of a nonendemic subspecies. Our results indicate that remnant populations are connected by significant dispersal to pollen sources up to 1.94 km away including the plantation. The combined analyses showed that the pollen pool and outcrossing rates of individuals within remnants varied significantly probably because of asynchronous flowering and that the likelihood of paternity was not correlated with spatial proximity. More than half of all progeny had male parents from outside their stand with the largest proportions estimated to come from the plantation by exclusion (42.4%) or Bayesian analyses (18.8–76%). Fragmentation may not be associated with decreased gene dispersal between populations of tree species, natural or planted, so that the distances required to buffer endemic trees in fragmented rural landscapes are likely to be large.
Spatiotemporal patterns of postsynaptic density (PSD)‐95 expression after rat spinal cord injury
Authors: Cheng C. , Gao S. , Zhao J. , Niu S. , Chen M. , Li X. , Qin J. , Shi S. , Guo Z. , Shen A.
Published: April 2008

Aims: Postsynaptic density (PSD)‐95 is a scaffolding protein linking the N‐methyl‐D‐aspartate receptor with neuronal nitric oxide synthase (nNOS), which contributes to many physiological and pathological actions. We here investigated whether PSD‐95 was involved in the secondary response following spinal cord injury (SCI). Methods: Spinal cord contusion (SCC) and spinal cord transection (SCT) models at thoracic (T) segment 9 (T9) were established in adults rats. Real‐time polymerase chain reaction, Western blot, immunohistochemistry and immunofluorescence were used to detect the temporal profile and spatial distribution of PSD‐95 after SCI. The association between PSD‐95 and nNOS in the injured cords was also assessed by coimmmunoprecipation and double immunofluorescent staining. Results: The mRNA and protein for PSD‐95 expression were significantly increased at 2 h or 8 h, and then gradually declined to the baseline level, ultimately up‐regulated again from 5 days to 7 days for its mRNA level and at 7 days or 14 days for its protein level after either SCC or SCT. PSD‐95 immunoreactivity was found in neurones, oligodendrocytes and synaptic puncta of spinal cord tissues within 5 mm from the lesion site. Importantly, injury‐induced expression of PSD‐95 was colabelled by active caspase‐3 (apoptotic marker), Tau‐1 (the marker for pathological oligodendrocytes) and nNOS. Conclusions: Accompanied by the spatio‐temporal changes for PSD‐95 expression, the association between PSD‐95 and nNOS undergoes substantial alteration after SCI. These two molecules are likely to form a complex on apoptotic neurones and pathological oligodendrocytes, which may in turn be involved in the secondary response after SCI.
The dorsal motor nucleus of the vagus is not an obligatory trigger site of Parkinson's disease: a critical analysis of α‐synuclein staging
Authors: Kalaitzakis M. E. , Graeber M. B. , Gentleman S. M. , Pearce R. K. B.
Published: April 2008

Aims: It has been proposed that alpha‐synuclein (αSyn) pathology in Parkinson's disease (PD) spreads in a predictable caudo‐rostral way with the earliest changes seen in the dorsal motor nucleus of the vagus nerve (DMV). However, the reliability of this stereotypical spread of αSyn pathology has been questioned. In addition, the comparative occurrence of αSyn pathology in the spinal cord and brain has not been closely studied. Methods: In order to address these issues, we have examined 71 cases of PD from the UK Parkinson's Disease Society Tissue Bank at Imperial College, London. The incidence and topographic distribution of αSyn pathology in several brain regions and the spinal cord were assessed. Results: The most affected regions were the substantia nigra (SN; in 100% of cases) followed by the Nucleus Basalis of Meynert (NBM) in 98.5%. Fifty‐three per cent of cases showed a distribution pattern of αSyn compatible with a caudo‐rostral spread of αSyn through the PD brain. However, 47% of the cases did not fit the predicted spread of αSyn pathology and in 7% the DMV was not affected even though αSyn inclusions were found in SN and cortical regions. We also observed a high incidence of αSyn in the spinal cord with concomitant affection of the DMV and in a few cases in the absence of DMV involvement. Conclusions: Our results demonstrate a predominant involvement of the SN and NBM in PD but do not support the existence of a medullary induction site of αSyn pathology in all PD brains.