bluuebunny/crossref_metadata_2025 huggingface dataset:
Promoting Long-lasting Learning Through Instructional Design
Authors: Hultberg Patrik , Santandreu Calonge David , Safiullin Lee Askhat Eugene
Published: October 2018

Passively listening to a lecture (deWinstanley & Bjork, 2002), skimming a textbook chapter, or googling for an answer to a homework problem is not conducive to deep and lasting high-order learning. At the same time, presenting complex concepts in problem-based classes might overload students’ working memory capacity. Effective student learning necessitates students to process information in their working memories, as well as storing information, facts and skills, in their long-term memories. Students must then be able to retrieve this information into their working memory in the future, in order to apply the information to new situations. That is, students must be able to recognize the characteristics of a future situation or problem and correctly retrieve the appropriate information stored in their long-term memory (Kirschner, Sweller, & Clark, 2006) to tackle the issue. Using the framework of Cognitive Load Theory, this article proposes an instructional model that promotes five strategies for learning and teaching; i.e. spacing, retrieval practice, elaboration, interleaving, and concrete examples, to effectively help students store and retrieve information from their long-term memory.
An Interdisciplinary Analysis of Course Meeting Frequency, Attendance and Performance
Authors: Pollak Micah , Parnell David Alan
Published: October 2018

Using data from Economics and History courses, taught across multiple semesters, we show that a triweekly meeting frequency improves student performance relative to a biweekly meeting frequency. We provide evidence that this effect operates through two channels. First, there is an indirect effect that operates through attendance. While greater attendance improves course score, this effect is less in a triweekly course. Second, there is a direct positive effect to more frequent course meetings on student performance. These two effects combine to increase student performance by 3 to 9 percentage points when meeting triweekly instead of biweekly. While students perform better overall on a triweekly meeting schedule, there are more absences and less consistent attendance.
Exploring students’ acceptance of educational computer games from the perspective of learning strategy
Authors: Huang Yong-Ming
Published: October 2018

Educational computer games have been widely employed to facilitate students’ learning. Studies have pointed out that these games may improve students’ learning effectiveness when they are equipped with appropriate learning strategies. However, the role of learning strategies in students’ acceptance of educational computer games has received surprisingly little scholarly attention. Hence, this research proposed two learning scenarios to address this question. Students in the first scenario were offered an educational computer game with a learning strategy, while those in the second were offered the same game without the strategy. A quasi-experimental design with a research model was constructed to examine the role of learning strategies in students’ acceptance of the given game. In this study, 65 students participated in the two learning scenarios. Two research findings are presented: (1) the adoption of the learning strategy not only affected students’ acceptance of the game, but also made their perceived ease of use significantly influence their perceived enjoyment, perceived usefulness, and attitude towards using; (2) with or without the learning strategy, perceived enjoyment was the most important factor that affected students’ acceptance of the game, while perceived usefulness, attitude towards using, and perceived control exerted no influence on this issue.
Framework for designing motivational augmented reality applications in vocational education and training
Authors: Bacca Acosta Jorge Luis , Baldiris Navarro Silvia Margarita , Fabregat Gesa Ramon , Kinshuk Kinshuk
Published: October 2018

One of the greatest advantages of augmented reality (AR) in education is that AR increases student motivation. Nevertheless, there is a gap between the research on student motivation in AR and the definition of frameworks to inform and guide the design and development of AR applications that effectively support student motivation. In this paper, we attempt to bridge that gap as we introduce and evaluate a framework for designing motivational AR applications. Our framework has been built upon three theoretical foundations: motivational design, universal design for learning and co-creation. The evaluation study was conducted with 58 chemistry students enrolled in the vocational education and training (VET) program for Laboratory Operations, and we found that the framework not only effectively supports the four dimensions of Keller's (2010) ARCS (attention, relevance, confidence and satisfaction) model of motivation, but also demonstrates exceptional results in the Attention and Confidence dimensions of motivation.
A Short Note on the Common Fixed Points of the Geraghty Contraction of Type ES,T
Authors: Alqahtani Badr , Fulga Andreea , Karapınar Erdal
Published: October 2018

In this paper, we propose a new contraction type for two self-mappings and investigate the necessary conditions for the existence and uniqueness of coincidence points and common fixed points, respectively. We put some examples to illustrate our main results.
An Instrumental Variables Design for the Effect of Emergency General Surgery
Authors: Keele Luke , Sharoky Catherine E. , Sellers Morgan M. , Wirtalla Chris J. , Kelz Rachel R.
Published: October 2018

Confounding by indication is a critical challenge in evaluating the effectiveness of surgical interventions using observational data. The threat from confounding is compounded when using medical claims data due to the inability to measure risk severity. If there are unobserved differences in risk severity across patients, treatment effect estimates based on methods such a multivariate regression may be biased in an unknown direction. A research design based on instrumental variables offers one possibility for reducing bias from unobserved confounding compared to risk adjustment with observed confounders. This study investigates whether a physician’s preference for operative care is a valid instrumental variable for studying the effect of emergency surgery. We review the plausibility of the necessary causal assumptions in an investigation of the effect of emergency general surgery (EGS) on inpatient mortality among adults using medical claims data from Florida, Pennsylvania, and New York in 2012–2013. In a departure from the extant literature, we use the framework of stochastic monotonicity which is more plausible in the context of a preference-based instrument. We compare estimates from an instrumental variables design to estimates from a design based on matching that assumes all confounders are observed. Estimates from matching show lower mortality rates for patients that undergo EGS compared to estimates based in the instrumental variables framework. Results vary substantially by condition type. We also present sensitivity analyses as well as bounds for the population level average treatment effect. We conclude with a discussion of the interpretation of estimates from both approaches.
Mitochondria-driven elimination of cancer and senescent cells
Authors: Hubackova Sona , Magalhaes Novais Silvia , Davidova Eliska , Neuzil Jiri , Rohlena Jakub
Published: October 2018

Mitochondria and oxidative phosphorylation (OXPHOS) are emerging as intriguing targets for the efficient elimination of cancer cells. The specificity of this approach is aided by the capacity of non-proliferating non-cancerous cells to withstand oxidative insult induced by OXPHOS inhibition. Recently we discovered that mitochondrial targeting can also be employed to eliminate senescent cells, where it breaks the interplay between OXPHOS and ATP transporters that appear important for the maintenance of mitochondrial morphology and viability in the senescent setting. Hence, mitochondria/OXPHOS directed pharmacological interventions show promise in several clinically-relevant scenarios that call for selective removal of cancer and senescent cells.
The role of the innate immune system on pulmonary infections
Authors: Galeas-Pena Michelle , McLaughlin Nathaniel , Pociask Derek
Published: October 2018

Inhalation is required for respiration and life in all vertebrates. This process is not without risk, as it potentially exposes the host to environmental pathogens with every breath. This makes the upper respiratory tract one of the most common routes of infection and one of the leading causes of morbidity and mortality in the world. To combat this, the lung relies on the innate immune defenses. In contrast to the adaptive immune system, the innate immune system does not require sensitization, previous exposure or priming to attack foreign particles. In the lung, the innate immune response starts with the epithelial barrier and mucus production and is reinforced by phagocytic cells and T cells. These cells are vital for the production of cytokines, chemokines and anti-microbial peptides that are critical for clearance of infectious agents. In this review, we discuss all aspects of the innate immune response, with a special emphasis on ways to target aspects of the immune response to combat antibiotic resistant bacteria.
A Versatile Converter of Liquid Hydrocarbons for the Production of Reducing and Carbonization Atmospheres
Authors: Al-Musa Abdullah A. , Martynenko Vladimir , Al-Saleh Mohammed , Al-Zahrani Ayman , Kalinin Vladimir , Shabunya Stanislav
Published: October 2018

We herein report the results of our investigation into the modes of catalytic partial oxidation (CPOX) of liquid fuels and air mixtures to yield endothermic (endo) gas on a pilot-scale installation containing ~ 0.45 cm3 catalytic bed. This endothermic gas serves as a protective atmosphere in thermochemical steel treatment processes. Seven liquid hydrocarbons (LHs) are investigated, namely isooctane, 91 RON (research octane number) and 95 RON gasoline, diesel, kerosene, jet fuel, and naphtha. All experiments are performed using our previously developed reactor, where the reactions of natural gas/air mixtures were previously studied. In the present study, we report that the LH conversion products reached an equilibrium state similar to that of methane and natural gas conversion with an atomic C/O ratio of ~ 1.0 in the mixture. Furthermore, working regimes between 850 and 950 °C are examined as typical reaction conditions for industrial endo gas generators, and in all cases, the required gas quality is achieved. However, we found that gasoline and diesel are the most suitable LH feedstock for endo gas generation.
Phase Locked Loop Based Techniques for Compensation of Voltage Based Power Quality Issues in Distribution System
Authors: Arya Sabha Raj , Maurya Rakesh , Naidu Talada Appala
Published: October 2018

This article describes the comparison of different phase locked loops (PLLs) based control algorithms for removal of voltage based power quality problems such as voltage sag/swell, distortions and unbalances etc. For this purpose, Dynamic Voltage Restorer (DVR) is designed with heuristic optimization technique called Multi-objective Grey wolf Optimizer (MOGWO) for PI gains calculation. Three PLLs namely adaptive transfer delay phase locked loop (ATD-PLL), multi complex coefficient filter phase locked loop (MCCF-PLL), and multi synchronous reference frame phase locked loop (MSRF-PLL) are implemented for the control of DVR in a three-phase system. These PLLs are employed for compensation of distortions and imbalances in supply along with voltage sag/swell. Basically, estimation of fundamental and positive sequence components are the basic function of these PLLs that is used for further extraction of reference load voltage. The optimization approach has been implemented for estimation of proportional integral (PI) gains of dc bus as well as ac bus in the system. This approach of tuning PI controller-gains reduces the time by integrating the fixed sized external archive to the GWO for saving and retrieving optimal solutions. Three wires DVR with developed control algorithms are implemented using MATLAB/Simulink and tested in a laboratory environment. The recorded results show satisfactory performance of DVR for compensation of voltage based power quality problems.
Reduced Switch Technique for Solar PV System Based Multilevel Inverter for PQ Improvement
Authors: Rajagopal V. , Nagamalleswari V. , Ray Papia , Arya Sabha Raj , Bangarraju J.
Published: October 2018

This paper describes reduced number of switches technique for Solar Photo Voltaic (SPV) voltage source based 31-level Multi Level Inverter (MLI) for Power Quality (PQ) improvement. The proposed topology reduces number of IGBT switches to ten, which is very less compared to diode clamped, capacitor and cascaded multilevel inverter. The desired multistep AC output voltage with minimum number of switches is obtained using this topology which reduces cost of system. The proposed MLI reduces number of harmonics at the AC output voltage which improves the PQ. The square wave switching used in this topology reduces the switching losses compared to pulse width modulation technique. The performance of four solar PV voltage sources with Buck/Boost converter has been discussed in this paper. The proposed MLI is mainly used in this paper for off grid system. The results of the Solar PV System based 31-level MLI have been simulated in MATLAB R2013a environment and hardware results have been validated using Opal-RT real time simulator OP-5142.
Popular lexicon of Greek origin in Italian varieties
Authors: Crifò Francesco
Published: October 2018

Greek-speaking people have been sailing the Mediterranean for millennia. At various stages of their development from Latin, the Romance languages have been influenced by their idiom. In Italy and in its islands, this role has been particularly evident due to the many rich and culturally active colonies in Southern Italy before and during the Roman period on the one hand, and through the later Byzantine occupation, which lasted several centuries in some areas, on the other. In this article, after a brief summary of the historical background (2.), the characteristics of the lexical borrowings from Greek in the local idioms of Southern (3.) as well as of Central and Northern Italy (4.) will be sketched. Here and there, and in the conclusions (5.), the status quaestionis and the latest orientations of the research will also be broadly outlined.
The vocabulary of the Algerian Lingua Franca
Authors: Baglioni Daniele
Published: October 2018

The so-called Mediterranean Lingua Franca is a Romance-based, onlyspoken linguistic variety that in slavery and travel accounts of the 17th-18th centuries is said to have been used by Moors and Turks, mainly in North Africa and above all in Algiers, as a basic means of communication with Christian slaves. Its only lexicographic source is an anonymous dictionary printed in Marseille in 1830, which is devoted to the Lingua Franca as it was spoken in Algiers. This source is by far the richest one available, but also the most problematic, because of its many inconsistencies and contradictions. As a result, the lexical components of the Algerian Lingua Franca (mainly Italian and Spanish, but also French, Provençal, Arabic, Turkish, etc.) as well as the quantity and quality of their contributions can only be reconstructed by critically comparing the entries of the Dictionnaire of 1830 with all preceding records by former prisoners and travellers.
Picturing Scripts: A Combined Narrative, Social Semiotic and Cognitive Approach to Visual Narrativity
Authors: Maagaard Cindie
Published: October 2018

This article explores visual narrativity through the case of prospective, or future-tense, narratives realized through visual images. Addressing the challenges of representing narrative elements of temporality, events and experience in a single, static image, it proposes an analytical framework combining social semiotic, contextual and cognitive perspectives. In doing so, it argues that a combined approach enhances our ability to understand the interplay between on the one hand the image-internal visual cues of temporality and modality that activate the viewer’s imagination and narrative inferences, and on the other, the processes by which such inferences are made, including the influence of the viewer’s contextual knowledge and cognitive processes in guiding them. The article uses architectural renderings as material for analysis, because they are exemplary of how visual images invite viewers to imagine the kinds of activities and experiences that can unfold in a future setting and thus make inferences about temporality, event and experience beyond the image’s isolated moment.
Application of a Custom-Synthesized Molecularly Imprinted Polymer for the Selective Isolation of Total Glucose and Fructose from 100% Fruit Juice Samples Prior to Instrumental Analysis
Authors: Mukami Hawa W. , Batlokwa Bareki S.
Published: October 2018

This article presents a novel sample preparation strategy that employed a custom-synthesized glucose - fructose (G-F) specific molecularly imprinted polymer (MIP) powder as an adsorbent for the simultaneous and selective extraction, isolation and pre-concentration of total glucose and fructose from the complex and `dirty` sample matrix of ‘100%’ fruit juices purchased from retail shops in Palapye, Botswana. The prepared G-F MIP powder demonstrated high selectivity, effective extraction and isolation for glucose and fructose from real samples of `100%` fruit juice samples as evidenced by the calculated high extraction efficiencies (EEs) of over 90%, with low percentage relative standard deviations (%RSD) of below 7% for n=6, for both glucose and fructose when compared to the low EEs of below 25% by the non-imprinted polymer (NIP), regarded as the control. Furthermore, the G-F MIP showed lower selectivity towards the analogous molecules; maltose and lactose as supported by the low EEs of below 31%. With the high affinity for glucose and fructose, the selective sample preparation strategy proposed herein presented itself as a potential procedure to be employed to improve the accurate analysis of adulterated artificial sugar sweeteners that are usually illegally added to the so-called `100%` fruit juices by producers to improve their taste.
Crystal structure of methyl 4-methyl-2,5-di(pyridin-4-yl)-1H-pyrrole-3-carboxylate monohydrate C17H15N3O2⋅H2O
Authors: Wang Chuan-Qi , Wang Xiao-Xia , Liu Xiao-Hu , Yang Bin-Yi , Zhong Qi-Di , Zhuang Peng-Yu , Tan Hong-Bo
Published: October 2018

C17H15N3O2⋅H2O, triclinic, P1̄ (no. 2), a = 5.7965(14) Å, b = 11.625(3) Å, c = 12.315(3) Å, α = 76.216(18)°, β = 76.674(18)°, β = 79.158(18)° V = 776.4(3) Å3, Z = 2, R
gt(F) = 0.0608, wR
ref(F
2) = 0.1574, T = 113 K.
The Option for the Poor and the Phenomenology of Life
Authors: Pastro Vincent J.
Published: October 2018

Recently, Catholic teaching and theology have given much attention to “the preferential option for the poor.” Gustavo Gutierrez, OP, who has popularized the phrase, also defines theology as a “reflection on praxis in the light of the word of God.” The praxis of the option for the poor is therefore indispensable to the theological task, for theology must always be “enfleshed” and concrete in the life of the people. This is particularly the case of Latin American theology and strongly emphasized in the magisterium of Pope Francis. The option for the poor has its foundation in who God is and how God is for the people (cf Exod 3:8-15). The option for the poor is grounded in life. Michel Henry’s phenomenology of life provides a logical approach to theological reflection on poverty, justice, and solidarity with the poor. The people of God, the Church community, live the option in concrete praxis. The God of life has a special love and concern for the poor. The poor, and those in solidarity with them, mysteriously experience the divine love and grace in their everyday lives and la lucha por la vida (the struggle for life). In the living, religious experience is intimately grounded.
I legati di Mileto e la pubblicazione delleVerrine: nota a CiceroneVerr.2.1.90
Authors: Ricchieri Tommaso
Published: October 2018

Discussion of the chronological problem posed by Cic.Verr.2.1.90, where Cicero states that the legates of Miletus are waiting for the consular elections for 69 AD, yet these had taken place before the start of the trial of Verres. It is proposed to explain this error as a ‘slip’ by Cicero due to the particular circumstances in which theActio secunda in Verremwas published; other cases of Ciceronian ‘author’s errors’ attested in theLetters to Atticusare cited.
Electroless plate of polyaniline-silver composite layer on polyester fibers
Authors: Liu Chang-Chun , Cheng Jin , Li Xiao-Qiang , Yue Pei-Pei , Gu Zhi-Jie , Ogino Kenji
Published: October 2018

Antistatic fibers or conductive fibers can be obtained from formation of a metal conductive layer, for example silver, on the surface of polymeric fibers through a redox reaction. However, in the process of fabricating silver-polymer conductive fibers, the binding force between silver and the polymeric fiber matrix is too weak and the poor weather resistance greatly affects the performance of the conductive fibers. This work aims to synthesize composite conductive layers of polyaniline (PANi)-silver coated on polyester fibers to prepare conductive polymeric fibers, in order to improve the combining ability between the conductive layers and the fiber matrix. The morphology, thermostability, mechanical properties, washing resistance and corrosion resistance of the resultant fibers obtained from different synthesis conditions were characterized. Batch experimental results showed that the concentration of the reagent and the reaction time could affect the resistance of the PANi-silver coated conductive fibers. The results also demonstrated that the PANi-silver composite conductive fibers have better properties than those of the silver-polymer conductive fibers.
Do patients undergoing cytoreductive surgery and HIPEC for peritoneal malignancy need parenteral nutrition?
Authors: Swain David R. , Yates Allison L. , Mohamed Faheez , Dayal Sanjeev P. , Tzivanakis Alexios , Cecil Tom D. , Moran Brendan J.
Published: October 2018

Background

To analyse the duration of parenteral nutrition (PN) in patients treated for peritoneal malignancy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) over a 2 year period at a single UK National referral centre.

Methods

A retrospective analysis of prospective data for all patients (n=321) who underwent CRS and HIPEC for peritoneal malignancy at the Peritoneal Malignancy Institute Basingstoke between April 1, 2013 and March 31, 2015.

Duration of PN was compared between primary tumour site (appendix, colorectal, mesothelioma and other); completeness of CRS (complete CRS vs. major tumour debulking) and pre-operative nutritional assessment measures (including Mid Upper Arm Circumference).

Results

The median duration of PN was 9 days (range 2–87 days). A total of 13 % of patients had PN for less than 7 days and 6 % for 5 days or less. There was no significant difference in duration of PN between the different tumour sites. Two factors that may increase the duration of PN include having major tumour debulking (MTD) and a baseline MUAC<23.5 cm.

Conclusions

Most patients who underwent CRS and HIPEC for peritoneal malignancy required PN for more than 7 days with poor pre-operative nutritional status and inability to achieve complete cytoreduction predictors of prolonged PN requirements.
Die Notwendigkeit ökonomischer Politikberatung für eine evidenzbasierte Bildungspolitik: Verkürzung und Verlängerung der Schulzeit am Gymnasium
Authors: Thomsen Stephan L. , Anger Silke
Published: October 2018

Ökonomische Argumentationsketten haben für bildungspolitische Entscheidungen in Deutschland seit den späten neunziger Jahren an Gewicht gewonnen. Insbesondere die viel diskutierten Reformen der Schulzeitverkürzung am Gymnasium von neun auf acht Jahre (Turbo-Abitur/G8-Reform) wurden ökonomisch begründet. Obwohl eine Vielzahl wissenschaftlicher Ergebnisse zu den Wirkungen des G8 verdeutlicht, dass eine Rückkehr zu G9 insgesamt nicht mit positiven Effekten verbunden sein dürfte, haben fünf Bundesländer kürzlich die neuerliche Verlängerung der Gymnasialschulzeit um ein Jahr beschlossen. Dies kann man als schwindenden Einfluss bildungsökonomischer Argumente in der politischen Entscheidungsfindung bewerten. Verantwortlich dafür sind nicht zuletzt das deutsche Wissenschaftssystem sowie seine Ökonominnen und Ökonomen. Eine Verbesserung der Anreize zur Beteiligung an wissenschaftlicher Politikberatung und Öffentlichkeitsarbeit, auch durch referierte deutschsprachige Publikationen, erscheint dringend geboten, um die ökonomischen Folgen in künftigen politischen Entscheidungen zu berücksichtigen.
Time-varying asymmetry and tail thickness in long series of daily financial returns
Authors: Mazur Błażej , Pipień Mateusz
Published: October 2018

We demonstrate that analysis of long series of daily returns should take into account potential long-term variation not only in volatility, but also in parameters that describe asymmetry or tail behaviour. However, it is necessary to use a conditional distribution that is flexible enough, allowing for separate modelling of tail asymmetry and skewness, which requires going beyond the skew-t form. Empirical analysis of 60 years of S&P500 daily returns suggests evidence for tail asymmetry (but not for skewness). Moreover, tail thickness and tail asymmetry is not time-invariant. Tail asymmetry became much stronger at the beginning of the Great Moderation period and weakened after 2005, indicating important differences between the 1987 and the 2008 crashes. This is confirmed by our analysis of out-of-sample density forecasting performance (using LPS and CRPS measures) within two recursive expanding-window experiments covering the events. We also demonstrate consequences of accounting for long-term changes in shape features for risk assessment.
A Note on Spectral Sublinearity for Collections of Positive Compact Operators on Banach Lattices
Authors: Kandić M.
Published: October 2018

In this paper we consider the question when a triangularizable semigroup S of positive compact ideal-triangularizable operators on an order continuous Banach lattice X is ideal-triangularizable. We prove that triangularizability always implies ideal-triangularizability iff X contains at most one atom. Under this condition we connect ideal-triangularizability of S with spectral properties of S. Surprisingly, S is idealtriangularizable iff the spectral radius is subadditive on S iff the spectral radius is submultiplicative on S. We also consider a pair of positive compact operators A and T with the property that A has a T-stable spectrum.
Product and factorization of hypo-EP operators
Authors: Johnson P. Sam , Vinoth A.
Published: October 2018

In this article, we derive some necessary and sufficient conditions for the product of hypo-EP operators to be hypo-EP and we characterize hypo-EP operators through factorizations.
Periodic Fitness Testing: Not Just for Athletes Anymore
Authors: Peterson David D.
Published: October 2018

STRENGTH AND CONDITIONING PROFESSIONALS, PERSONAL TRAINERS, AND COMPETITIVE ATHLETES HAVE LONG USED PERIODIC FITNESS TESTING AS AN EFFECTIVE TRAINING PRACTICE. THIS CONCEPT IS RARELY USED, HOWEVER, BY THE NOVICE EXERCISER OR GENERAL PUBLIC. IN ADDITION, MOST OF THE CURRENT FITNESS TESTS ASSESS ONLY A FEW OF THE DIFFERENT COMPONENTS OF FITNESS. UNLIKE CURRENT FITNESS TESTS, THE PROPOSED ASSESSMENT EVALUATES 10 OF THE DIFFERENT COMPONENTS OF FITNESS, THEREBY PROVIDING USERS WITH A MORE COMPLETE OVERVIEW OF THEIR CURRENT FITNESS. IN ADDITION, IF USERS ARE FOUND DEFICIENT IN A PARTICULAR COMPONENT(S) OF FITNESS, THE PROPOSED ASSESSMENT PROVIDES SPECIFIC TRAINING RECOMMENDATIONS FOR IMPROVEMENT.
Accessibility of the Mental Representation of Attachment Figures in Patients With Anxiety and Depressive Symptoms
Authors: Karreman Annemiek , Bachrach Nathan , Robeers Charlotte M. M. H. , Bekker Marrie H. J.
Published: October 2018

According to attachment theory, different attachment styles relate to individuals' innate behaviors aimed at establishing proximity to or distancing oneself from attachment figures when confronted with threat. Unclear is whether these attachment-related threat responses also pertain to clinically depressed or anxious individuals. We therefore examined attachment-related patterns of accessibility of attachment figure representations under threat in 60 patients with anxiety and depressive symptoms (aged 16–58; primary diagnoses: an anxiety disorder, mood disorder, or personality disorder), applying an experimental Stroop procedure. Participants, randomly assigned to one of three priming conditions (neutral, attachment-unrelated threatening, attachment-related threatening prime), were exposed to a person's name preceded by a subliminal prime. Self-reported attachment styles, trait anxiety, and depressive symptoms were measured. Participants with higher scores on attachment avoidance showed reduced accessibility of persons in a neutral context and in response to attachment-unrelated threat, but not in response to attachment-related threat. These effects were independent of trait anxiety and depressive symptoms. Attachment anxiety was not associated with accessibility of persons. These results indicate that the mechanism of attachment-related responses to threat might not pertain to patients with anxiety and depressive symptoms, possibly due to collapse under their chronic strain.
Nonlinear Lateral Interactions in V1 Population Responses Explained by a Contrast Gain Control Model
Authors: Michel Melchi M. , Chen Yuzhi , Seidemann Eyal , Geisler Wilson S.
Published: October 2018

How do cortical responses to local image elements combine to form a spatial pattern of population activity in primate V1? Here, we used voltage-sensitive dye imaging, which measures summed membrane potential activity, to examine the rules that govern lateral interactions between the representations of two small local-oriented elements in macaque (Macaca mulatta) V1. We find strong subadditive and mostly orientation-independent interactions for nearby elements [2–4 mm interelement cortical distance (IED)] that gradually become linear at larger separations (>6 mm IED). These results are consistent with a population gain control model describing nonlinear V1 population responses to single oriented elements. However, because of the membrane potential-to-spiking accelerating nonlinearity, the model predicts supra-additive lateral interactions of spiking responses for intermediate separations at a range of locations between the two elements, consistent with some prior facilitatory effects observed in electrophysiology and psychophysics. Overall, our results suggest that population-level lateral interactions in V1 are primarily explained by a simple orientation-independent contrast gain control mechanism.

SIGNIFICANCE STATEMENTInteractions between representations of simple visual elements such as oriented edges in primary visual cortex (V1) are thought to contribute to our ability to easily integrate contours and segment surfaces, but the mechanisms that govern these interactions are primarily unknown. Our study provides novel evidence that lateral interactions at the population level are governed by a simple contrast gain–control mechanism, and we show how this divisive gain–control mechanism can give rise to apparently facilitatory spiking responses.
Abstract Representation of Prospective Reward in the Hippocampus
Authors: Zeithamova Dagmar , Gelman Bernard D. , Frank Lea , Preston Alison R.
Published: October 2018

Motivation enhances memory by increasing hippocampal engagement during encoding. However, whether such increased hippocampal activation reflects encoding of the value of highly rewarding events per se is less understood. Here, using a monetary incentive encoding task with a novel manipulation, we tested in humans whether the hippocampus represents abstract reward value, independent of perceptual content. During functional MRI scanning, men and women studied object pairs, each preceded by a monetary reward cue indicating the amount of money they would receive if they successfully remembered the object pair at test. Reward cues varied on both the level of reward (penny, dime, and dollar) and visual form (picture or word) across trials to dissociate hippocampal responses to reward value from those reflecting the perceptual properties of the cues. Behaviorally, participants remembered pairs associated with the high reward (dollar) more often than pairs associated with lower rewards. Neural pattern-similarity analysis revealed that hippocampal and parahippocampal cortex activation patterns discriminated between cues of different value regardless of their visual form, and that hippocampal discrimination of value was most pronounced in participants who showed the greatest behavioral sensitivity to reward. Strikingly, hippocampal patterns were most distinct for reward cues that differed in value but had similar visual appearance, consistent with theoretical proposals of hippocampal-pattern differentiation of competing representations. Our data illustrate how contextual representations within the hippocampus go beyond space and time to include information about the motivational salience of events, with hippocampal reward coding tracking the motivational impact on later memory.

SIGNIFICANCE STATEMENTMotivation, such as the promise of future rewards, enhances hippocampal engagement during encoding and promotes successful retention of events associated with valuable rewards. However, whether the hippocampus explicitly encodes reward value, dissociable from sensory information, is unclear. Here, we show that the hippocampus forms abstract representation of valuable rewards, encoding conceptual rather than perceptual information about the motivational context of individual events. Reward representation within the hippocampus is associated with preferential retention of high-value events in memory. Furthermore, we show that hippocampal-pattern differentiation serves to emphasize differences between visually similar events with distinct motivational salience. Collectively, these findings indicate that hippocampal contextual representations enable individuals to distinguish the motivational value of events, leading to prioritized encoding of significant memories.
Aggrecan Directs Extracellular Matrix-Mediated Neuronal Plasticity
Authors: Rowlands Daire , Lensjø Kristian K. , Dinh Tovy , Yang Sujeong , Andrews Melissa R. , Hafting Torkel , Fyhn Marianne , Fawcett James W. , Dick Gunnar
Published: October 2018

In the adult brain, the extracellular matrix (ECM) influences recovery after injury, susceptibility to mental disorders, and is in general a strong regulator of neuronal plasticity. The proteoglycan aggrecan is a core component of the condensed ECM structures termed perineuronal nets (PNNs), and the specific role of PNNs on neural plasticity remains elusive. Here, we genetically targeted theAcangene encoding for aggrecan using a novel animal model. This allowed for conditional and targeted loss of aggrecanin vivo, which ablated the PNN structure and caused a shift in the population of parvalbumin-expressing inhibitory interneurons toward a high plasticity state. Selective deletion of theAcangene in the visual cortex of male adult mice reinstated juvenile ocular dominance plasticity, which was mechanistically identical to critical period plasticity. Brain-wide targeting improved object recognition memory.

SIGNIFICANCE STATEMENTThe study provides the first direct evidence of aggrecan as the main functional constituent and orchestrator of perineuronal nets (PNNs), and that loss of PNNs by aggrecan removal induces a permanent state of critical period-like plasticity. Loss of aggrecan ablates the PNN structure, resulting in invoked juvenile plasticity in the visual cortex and enhanced object recognition memory.
Opposite Dynamics of GABA and Glutamate Levels in the Occipital Cortex during Visual Processing
Authors: Kurcyus Katarzyna , Annac Efsun , Hanning Nina M. , Harris Ashley D. , Oeltzschner Georg , Edden Richard , Riedl Valentin
Published: October 2018

Magnetic resonance spectroscopy (MRS) measures the two most common inhibitory and excitatory neurotransmitters, GABA and glutamate, in the human brain. However, the role of MRS-derived GABA and glutamate signals in relation to system-level neural signaling and behavior is not fully understood. In this study, we investigated levels of GABA and glutamate in the visual cortex of healthy human participants (both genders) in three functional states with increasing visual input. Compared with a baseline state of eyes closed, GABA levels decreased after opening the eyes in darkness and Glx levels remained stable during eyes open but increased with visual stimulation. In relevant states, GABA and Glx correlated with amplitude of fMRI signal fluctuations. Furthermore, visual discriminatory performance correlated with the level of GABA, but not Glx. Our study suggests that differences in brain states can be detected through the contrasting dynamics of GABA and Glx, which has implications in interpreting MRS measurements.

SIGNIFICANCE STATEMENTGABA and glutamate are the two most abundant neurotransmitters in human brain. Their interaction, known as inhibitory-excitatory balance, plays a crucial role in establishing spontaneous and stimulus-driven brain activity. Yet, the relationship between magnetic resonance spectroscopy (MRS)-derived levels of both metabolites and fMRI is still a matter of dispute. In this work, we study GABA and glutamate in three states of visual processing and in relation to fMRI and visual discriminatory performance in healthy people. We found that states of visual processing can be detected through the contrasting dynamics of GABA and glutamate and their correlation with fMRI signals. We also demonstrated that GABA, but not glutamate, in the visual system predicts visual performance. Our results provide insights into MRS-derived GABA and glutamate measurements.
A Pool of Postnatally Generated Interneurons Persists in an Immature Stage in the Olfactory Bulb
Authors: Benito Nuria , Gaborieau Elodie , Sanz Diez Alvaro , Kosar Seher , Foucault Louis , Raineteau Olivier , De Saint Jan Didier
Published: October 2018

Calretinin (CR)-expressing periglomerular (PG) cells are the most abundant interneurons in the glomerular layer of the olfactory bulb. They are predominately generated postnatally from the septal and dorsal subventricular zones that continue producing them well into adulthood. Yet, little is known about their properties and functions. Using transgenic approaches and patch-clamp recording in mice of both sexes we show that CR(+) PG cells of both septal and dorsal origin have homogeneous morphological and electrophysiological properties. However, unlike other PG cells, these axonless neurons express a surprisingly small repertoire of voltage-activated channels and do not fire or fire at most a single and often small action potential. Moreover, they are not innervated by olfactory sensory neurons and receive little synaptic inputs from mitral or tufted cells at excitatory synapses where NMDA receptors predominate. These membrane and synaptic properties, that resemble those of newborn immature neurons not yet integrated in the network, persist over time and limit the recruitment of CR(+) PG cells by afferent inputs that strongly drive local network activity. Together, our results show that postnatally generated CR(+) PG cells continuously supply a large pool of neurons with unconventional properties. These data also question the contribution of CR(+) PG cells in olfactory bulb computation.

SIGNIFICANCE STATEMENTCalretinin-expressing PG cells are by far the most abundant interneurons in the glomerular layer of the olfactory bulb. They are continuously produced during postnatal life, including adulthood, from neural stem cells located in the subventricular zones. Surprisingly, unlike other postnatally generated newborn neurons that quickly integrate into preexisting olfactory bulb networks, calretinin-expressing PG cells retain immature properties that limit their recruitment in local network activity for weeks, if not months, as if they would never fully mature. The function of this so far unsuspected pool of latent neurons is still unknown.
Nucleus Reuniens Is Required for Encoding and Retrieving Precise, Hippocampal-Dependent Contextual Fear Memories in Rats
Authors: Ramanathan Karthik R. , Ressler Reed L. , Jin Jingji , Maren Stephen
Published: October 2018

The nucleus reuniens (RE) is a ventral midline thalamic nucleus that interconnects the medial prefrontal cortex (mPFC) and hippocampus (HPC). Considerable data indicate that HPC–mPFC circuits are involved in contextual and spatial memory; however, it is not clear whether the RE mediates the acquisition or retrieval of these memories. To examine this question, we inactivated the RE with muscimol before either the acquisition or retrieval of pavlovian fear conditioning in rats; freezing served as the index of fear. We found that RE inactivation before conditioning impaired the acquisition of contextual freezing, whereas inactivation of the RE before retrieval testing increased the generalization of freezing to a novel context; inactivation of the RE did not affect either the acquisition or expression of auditory fear conditioning. Interestingly, contextual conditioning impairments were absent when retrieval testing was also conducted after RE inactivation. Contextual memories acquired under RE inactivation were hippocampal independent, insofar as contextual freezing in rats conditioned under RE inactivation was insensitive to intrahippocampal infusions of the NMDA receptor antagonist aminophosphonovalerate. Together, these data reveal that the RE supports hippocampal-dependent encoding of precise contextual memories that allow discrimination of dangerous contexts from safe contexts. When the RE is inactive, however, alternate neural systems acquire an impoverished contextual memory that is expressed only when the RE is off-line.

SIGNIFICANCE STATEMENTThe midline thalamic nucleus reuniens (RE) coordinates communication between the hippocampus and medial prefrontal cortex, brain areas that are critical for contextual and spatial memory. Here we show that temporary pharmacological inactivation of RE impairs the acquisition and precision of contextual fear memories after pavlovian fear conditioning in rats. However, inactivating the RE before retrieval testing restored contextual memory in rats conditioned after RE inactivation. Critically, we show that imprecise contextual memories acquired under RE inactivation are learned independently of the hippocampus. These data reveal that the RE is required for hippocampal-dependent encoding of precise contextual memories to support the discrimination of safe and dangerous contexts.
NSIS: Proceedings of the Nova Scotian Institute of Science
Authors: Introduction Introduction
Published: October 2018

Introduction
GENERAL INTRODUCTION: CONSERVING NOVA SCOTIA’S BIODIVERSITY
Authors: Willison J.H.Martin
Published: October 2018

The papers on biodiversity in this issue focus on the richness of life in Nova Scotia, and the means by which this richness might be conserved. Mammals, birds, fish, beetles, and diatoms are examples of the richness of life described in the volume. The conservation status of selected species is outlined, as are the threats to these species. Special attention is paid to moose and roseate terns, and a wide range of birds, beetles, fish, mammals and other species receive some attention. Conservation options based on the protection of habitat in Nova Scotia, as well as comprehensive landscape-scale strategies for biodiversity conservation planning, are similarly described both in detail and in general by a variety of authors.Les articles du présent volume portent principalement sur la richesse du vivant en Nouvelle-Écosse et sur les moyens de conserver cette richesse. Mammifères, oiseaux, poissons, coléoptères et diatomées sont au nombre des taxons traités dans le volume. On décrit la situation de certaines espèces et les menaces qui pèsent sur elles. Une attention particulière est accordée à l’orignal et à la Sterne de Dougall, et une grande variété d’oiseaux, de coléoptères, de poissons, de mammifères et d’autres espèces sont également considérées. Plusieurs auteurs décrivent de manière générale ou détaillée des options en matière de conservation fondées sur la protection des habitats en Nouvelle-Écosse ainsi que des stratégies globales à l’échelle des paysages pour la planification de la conservation de la biodiversité.
THE DISTRIBUTION, STATUS AND HABITAT ASSOCIATIONS OF MOOSE IN MAINLAND NOVA SCOTIA
Authors: Snaith Tamaini V. , Beazley Karen F.
Published: October 2018

Throughout the Nova Scotia mainland, small and fragmented moose populations remain at varying densities and may be limited or regulated by a number of factors including interspecific competition, disease, habitat alteration/loss, mineral toxicity/deficiency, predation, poaching, and resource availability. Ranging behaviour and habitat requirements vary according to environmental factors; however, moose require food and cover in sufficient quantity and of appropriate interspersion to meet their daily and seasonal needs. Mature forest with a well developed understory, and open areas with early successional vegetation provide forage, while dense forest provides cover from thermal stress and deep snow. Strategies for moose conservation, such as through forest management, should concentrate on the preservation and enhancement of habitat to meet the critical requirements of viable moose populations and the re-establishment of connections among discrete populations.Sur la terre ferme en Nouvelle-Écosse, il reste de petites populations fragmentées d’orignaux de densités variables qui sont peut-être limitées ou régulées par plusieurs facteurs dont la compétition interspécifique, les maladies, l’altération ou la destruction des habitats, la toxicité des minéraux ou le manque de minéraux, la prédation, le braconnage et la disponibilité des ressources. Les déplacements et les besoins en matière d’habitat des orignaux varient en fonction des facteurs environnementaux; cependant, les orignaux ont besoin de nourriture et d’un couvert adéquatement répartis pour satisfaire leurs besoins quotidiens et saisonniers. Les forêts matures à sous-étage bien développé et les zones ouvertes caractérisées par des espèces végétales pionnières fournissent la nourriture, tandis que les forêts denses offrent un couvert contre le stress thermique et la neige épaisse. Les stratégies de conservation des orignaux, par exemple associées à l’aménagement des forêts, devraient viser principalement la conservation et l’amélioration de l’habitat de manière à combler les besoins essentiels des populations viables d’orignaux, ainsi que le rétablissement de la connectivité entre les populations disjointes.
NSIS Proceedings: Introduction
Authors: NSIS Proceedings: Introduction and Executive Introduction
Published: October 2018

Introduction and executive.