Old-new ERP effects and remote memories : the late parietal effect is absent as recollection fails whereas the early mid-frontal effect persists as familiarity is retained

Acknowledgments Wael El-Deredy acknowledges the support from CONICYT Basal project FB0008, Chile.The authors would like to thank the two reviewers for their very useful suggestions and comments.Peer reviewedPublisher PD

Thaumasite form of sulfate attack in limestone cement mortars: A study on long term efficiency of mineral admixtures

Concrete and mortar made from limestone cement may exhibit a lack of durability due to the formation of thaumasite. The addition of minerals that improve the concrete durability is expected to slow down the formation of thaumasite. in this work the effect of natural pozzolana, fly ash, ground granulated blast-furnace slag and metakaolin on the thaumasite formation in limestone cement mortar is examined. A limestone cement, containing 15% w/w limestone, was used. Mortar specimens were prepared by replacing a part of limestone cement with the above minerals. The specimens were immersed in a 1.8% MgSO4 solution and cured at 5 and 25 degrees C. The status of the samples after a storage period of 5 years was reported based on visual inspection, compressive strength, mass measurements, ultrasonic pulse velocity measurements and analytical techniques. It is concluded that the use of specific minerals, as partial replacement of cement, inhibits thaumasite formation in limestone cement mortar. (C) 2008 Elsevier Ltd. All rights reserved

The efficacy of single-trial multisensory memories.

This review article summarizes evidence that multisensory experiences at one point in time have long-lasting effects on subsequent unisensory visual and auditory object recognition. The efficacy of single-trial exposure to task-irrelevant multisensory events is its ability to modulate memory performance and brain activity to unisensory components of these events presented later in time. Object recognition (either visual or auditory) is enhanced if the initial multisensory experience had been semantically congruent and can be impaired if this multisensory pairing was either semantically incongruent or entailed meaningless information in the task-irrelevant modality, when compared to objects encountered exclusively in a unisensory context. Processes active during encoding cannot straightforwardly explain these effects; performance on all initial presentations was indistinguishable despite leading to opposing effects with stimulus repetitions. Brain responses to unisensory stimulus repetitions differ during early processing stages (-100 ms post-stimulus onset) according to whether or not they had been initially paired in a multisensory context. Plus, the network exhibiting differential responses varies according to whether or not memory performance is enhanced or impaired. The collective findings we review indicate that multisensory associations formed via single-trial learning exert influences on later unisensory processing to promote distinct object representations that manifest as differentiable brain networks whose activity is correlated with memory performance. These influences occur incidentally, despite many intervening stimuli, and are distinguishable from the encoding/learning processes during the formation of the multisensory associations. The consequences of multisensory interactions that persist over time to impact memory retrieval and object discrimination

THE HYDROMAGNESITE DEPOSITS OF THE ATLIN AREA, BRITISH COLUMBIA, CANADA, AND THEIR INDUSTRIAL POTENTIAL AS A FIRE RETARDANT

Η έρευνα αυτή έχει ως στόχο την μελέτη των αποθέσεων υδρομαγνησίτη της περιοχής Atlin της Βρετανικής Κολομβίας στον Καναδά και τη δυνατότητα αξιοποίησης τους στην διεθνή αγορά των επιβραδυντών καύσεως. Οι ορυκτοί επιβραδυντές καύσης, όπως τα Mg- και Ca/Mg-ανθρακικά πετρώματα, είναι φιλικοί προς το περιβάλλον, καθώς παράγουν μη-τοξικά και μη-διαβρωτικά αέρια και θεωρούνται ασφαλέστεροι. Στα πλαίσια αυτής της έρευνας, συλλέγησαν και αναλύθηκαν εβδομήντα αναγνωριστικά και δύο ολικά δείγματα από την εν λόγω περιοχή. Τα αποτελέσματα έδειξαν ότι τα ανωτέρω δείγματα αποτελούνται κυρίως από υδρομαγνησίτη, με μικρά ποσοστά πολύ λεπτόκοκκου, μαλακού και πεπλατυσμένου μαγνησίτη. Το γενικό συμπέρασμα είναι ότι η ορυκτολογική σύσταση των δειγμάτων, η συμπεριφορά τους κατά τη θερμική αποσύνθεση, καθώς και οι χημικές και φυσικές τους ιδιότητες, τα καθιστούν κατάλληλα για χρήση τους ως υλικά πυροπροστασίας. Επιπλέον, η ^κότητα των δειγμάτων είναι αρκετά υψηλή και συγκρίσιμη με άλλα εμπορεύσιμα υλικά που περιέχουν υδρομαγνησίτη. Τα αποθέματα υδρομαγνησίτη στην περιοχή Atlin είχαν υπερεκτιμηθεί στο παρελθόν στους 110.000 τόνους. Προτείνεται μια τεχνο-οικονομική εκτίμηση για να πραγματοποιηθεί ένας πιο ακριβής υπολογισμός των αποθεμάτων της περιοχήςThis research examines the potential of the hydromagnesite deposits at Atlin in British Columbia, Canada, for the mineral fire-retardant market. Mineral fire retardants, such as Mg- and Ca/Mg-carbonates, are environmentally friendly, producing non-toxic and non-corrosive gases during their thermal decomposition. During this research, 70 sediment samples and two bulk samples were collected from the study area and analysed. The results showed that the Atlin deposits are composed mostly of hydromagnesite with minor amounts of very fine-grained, soft and platy magnesite. The general conclusion is that the mineralogical composition of the samples, their behavior during thermal decomposition, and their chemical and physical properties, make them suitable for use as white fillers for flame-retardants. Additionally, the whiteness of the samples is sufficient and comparable to other commercial hydromagnesite-bearing rocks. The Atlin reserves of the hydromagnesite ore bodies were overestimated in past literature as 110,000 tons. A more precise calculation of the reserves during a technoeconomic assessment is required

THE HYDROMAGNESITE DEPOSITS OF THE ATLIN AREA, BRITISH COLUMBIA, CANADA, AND THEIR INDUSTRIAL POTENTIAL AS A FIRE RETARDANT

Η έρευνα αυτή έχει ως στόχο την μελέτη των αποθέσεων υδρομαγνησίτη της περιοχής Atlin της Βρετανικής Κολομβίας στον Καναδά και τη δυνατότητα αξιοποίησης τους στην διεθνή αγορά των επιβραδυντών καύσεως. Οι ορυκτοί επιβραδυντές καύσης, όπως τα Mg- και Ca/Mg-ανθρακικά πετρώματα, είναι φιλικοί προς το περιβάλλον, καθώς παράγουν μη-τοξικά και μη-διαβρωτικά αέρια και θεωρούνται ασφαλέστεροι. Στα πλαίσια αυτής της έρευνας, συλλέγησαν και αναλύθηκαν εβδομήντα αναγνωριστικά και δύο ολικά δείγματα από την εν λόγω περιοχή. Τα αποτελέσματα έδειξαν ότι τα ανωτέρω δείγματα αποτελούνται κυρίως από υδρομαγνησίτη, με μικρά ποσοστά πολύ λεπτόκοκκου, μαλακού και πεπλατυσμένου μαγνησίτη. Το γενικό συμπέρασμα είναι ότι η ορυκτολογική σύσταση των δειγμάτων, η συμπεριφορά τους κατά τη θερμική αποσύνθεση, καθώς και οι χημικές και φυσικές τους ιδιότητες, τα καθιστούν κατάλληλα για χρήση τους ως υλικά πυροπροστασίας. Επιπλέον, η ^κότητα των δειγμάτων είναι αρκετά υψηλή και συγκρίσιμη με άλλα εμπορεύσιμα υλικά που περιέχουν υδρομαγνησίτη. Τα αποθέματα υδρομαγνησίτη στην περιοχή Atlin είχαν υπερεκτιμηθεί στο παρελθόν στους 110.000 τόνους. Προτείνεται μια τεχνο-οικονομική εκτίμηση για να πραγματοποιηθεί ένας πιο ακριβής υπολογισμός των αποθεμάτων της περιοχήςThis research examines the potential of the hydromagnesite deposits at Atlin in British Columbia, Canada, for the mineral fire-retardant market. Mineral fire retardants, such as Mg- and Ca/Mg-carbonates, are environmentally friendly, producing non-toxic and non-corrosive gases during their thermal decomposition. During this research, 70 sediment samples and two bulk samples were collected from the study area and analysed. The results showed that the Atlin deposits are composed mostly of hydromagnesite with minor amounts of very fine-grained, soft and platy magnesite. The general conclusion is that the mineralogical composition of the samples, their behavior during thermal decomposition, and their chemical and physical properties, make them suitable for use as white fillers for flame-retardants. Additionally, the whiteness of the samples is sufficient and comparable to other commercial hydromagnesite-bearing rocks. The Atlin reserves of the hydromagnesite ore bodies were overestimated in past literature as 110,000 tons. A more precise calculation of the reserves during a technoeconomic assessment is required

Hippocampal - diencephalic - cingulate networks for memory and emotion: An anatomical guide

This review brings together current knowledge from tract tracing studies to update and reconsider those limbic connections initially highlighted by Papez for their presumed role in emotion. These connections link hippocampal and parahippocampal regions with the mammillary bodies, the anterior thalamic nuclei, and the cingulate gyrus, all structures now strongly implicated in memory functions. An additional goal of this review is to describe the routes taken by the various connections within this network. The original descriptions of these limbic connections saw their interconnecting pathways forming a serial circuit that began and finished in the hippocampal formation. It is now clear that with the exception of the mammillary bodies, these various sites are multiply interconnected with each other, including many reciprocal connections. In addition, these same connections are topographically organised, creating further subsystems. This complex pattern of connectivity helps explain the difficulty of interpreting the functional outcome of damage to any individual site within the network. For these same reasons, Papez’s initial concept of a loop beginning and ending in the hippocampal formation needs to be seen as a much more complex system of hippocampal–diencephalic–cingulate connections. The functions of these multiple interactions might be better viewed as principally providing efferent information from the posterior medial temporal lobe. Both a subcortical diencephalic route (via the fornix) and a cortical cingulate route (via retrosplenial cortex) can be distinguished. These routes provide indirect pathways for hippocampal interactions with prefrontal cortex, with the preponderance of both sets of connections arising from the more posterior hippocampal regions. These multi-stage connections complement the direct hippocampal projections to prefrontal cortex, which principally arise from the anterior hippocampus, thereby creating longitudinal functional differences along the anterior–posterior plane of the hippocampus

Explicit Mentalizing Mechanisms and Their Adaptive Role in Memory Conformity

Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a ‘forensic’ perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe) systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation

Dissociating recollection from familiarity: electrophysiological evidence that familiarity for faces is associated with a posterior old/new effect

In recognition memory research, a tension exists between dual-process and single-process models of episodic retrieval. Dual-process models propose that ‘familiarity’ assessment and the ‘recollection’ of contextual information are independent processes, while single process models claim that one common process supports retrieval. Event-related potentials (ERPs) have been used to show dissociations between the mid frontal and the left parietal ERP old/new effects, which have been associated with familiarity and recollection, respectively. While much ERP evidence favours dual-process theory, Yovel and Paller (2004) used faces as retrieval cues to demonstrate that posterior old/new effects index both familiarity and recollection, a finding consistent with single process models. Here we present evidence supporting Yovel and Paller’s claim that a posterior old/new effect indexes familiarity for faces, along with a novel finding that recollection is associated with an anterior old/new effect. Importantly, and in contrast to Yovel and Paller, the old/new effects associated with familiarity and recollection were topographically dissociable, consistent with a dual process view of recognition memory. The neural correlates of familiarity and recollection identified here for faces appear to be different from those typically observed, suggesting that the ERP old/new effects associated with episodic recognition are not the same under all circumstances