Distinct Aspects Research Articles

Branch-and-cut algorithms for the covering salesman problem

The Covering Salesman Problem (CSP) is a generalization of the Traveling Salesman Problem in which the tour is not required to visit all vertices, as long as all vertices are covered by the tour. The objective of CSP is to find a minimum length Hamiltonian cycle over a subset of vertices that covers an undirected graph. In this paper, valid inequalities from the generalized traveling salesman problem are applied to the CSP in addition to new valid inequalities that explore distinct aspects of the problem. A branch-and-cut framework assembles exact and heuristic separation routines for integer and fractional CSP solutions. Computational experiments show that the proposed framework outperformed methodologies from literature with respect to optimality gaps. Moreover, optimal solutions were proven for several previously unsolved instances.

Do Performance Aspirations Matter for Guiding Software Configuration Tuning? An Empirical Investigation under Dual Performance Objectives

Configurable software systems can be tuned for better performance. Leveraging on some Pareto optimizers, recent work has shifted from tuning for a single, time-related performance objective to two intrinsically different objectives that assess distinct performance aspects of the system, each with varying aspirations to be satisfied, e.g., “ the latency is less than 10s ” while “ the memory usage is no more than 1GB ”. Before we design better optimizers, a crucial engineering decision to make therein is how to handle the performance requirements with clear aspirations in the tuning process. For this, the community takes two alternative optimization models: either quantifying and incorporating the aspirations into the search objectives that guide the tuning, or not considering the aspirations during the search but purely using them in the later decision-making process only. However, despite being a crucial decision that determines how an optimizer can be designed and tailored, there is a rather limited understanding of which optimization model should be chosen under what particular circumstance, and why. In this article, we seek to close this gap. Firstly, we do that through a review of over 426 articles in the literature and 14 real-world requirements datasets, from which we summarize four performance requirement patterns that quantify the aspirations in the configuration tuning. Drawing on these, we then conduct a comprehensive empirical study that covers 15 combinations of the state-of-the-art performance requirement patterns, four types of aspiration space, three Pareto optimizers, and eight real-world systems/environments, leading to 1,296 cases of investigation. Our findings reveal that (1) the realism of aspirations is the key factor that determines whether they should be used to guide the tuning; (2) the given patterns and the position of the realistic aspirations in the objective landscape are less important for the choice, but they do matter to the extents of improvement; (3) the available tuning budget can also influence the choice for unrealistic aspirations but it is insignificant under realistic ones. To promote open science practice, we make our code and dataset publicly available at: https://github.com/ideas-labo/aspiration-study .

Structural and magnetic properties of Fe–Ti–O solid solution prepared by ball-milling and post annealing

We investigate the structural and magnetic properties of a Fe–Ti–O system prepared by ball-milling and post annealing from γ-Fe2O3 and TiO2-anatase. From a systematic analysis of the structural properties, we show that our sample consists of a Fe–Ti–O solid solution, in which the Ti acts as dopant in the hematite structure. Moreover, by exploring distinct aspects of the magnetic behavior, we reveal that our sample presents a magnetic behavior that is strongly dependent on the temperature. Although the Fe–Ti–O solid solution carries the ordinary magnetic behavior expected for the hematite over most of the investigated temperature range, we verify quite-interesting features of magnetic origin taking place at lower temperatures. We interpret them as fingerprints of cluster spin freezing effect and provide experimental evidence supporting the existence of the glassy state below ∼51 K.

Self-Report Survey Measures of Alcohol-Impaired Driving: A Systematic Review.

Alcohol-impaired driving is a major contributor to motor vehicle crash deaths and injury. Many survey studies include self-report measures of alcohol-impaired driving, but no guidance is available to help researchers select from among available measures. The aims of this systematic review were to compile a list of measures that researchers have used previously, to compare performance between measures, and to identify the measures with highest validity and reliability. Literature searches of PubMed, Scopus, and Web of Science identified studies that assessed alcohol-impaired driving behavior through self-report. The measures from each study and, if available, indices of reliability or validity were extracted. Using the measures' text, we developed 10 codes to group similar measures and compare them. For example, the "alcohol effects" code refers to driving while feeling dizzy or lightheaded after drinking, and the "drink count" code pertains to the number of drinks someone consumed before driving. For measures with multiple items, each item was categorized separately. After screening according to the eligibility criteria, 41 articles were included in the review. Thirteen articles reported on reliability. No articles reported on validity. The self-report measures with the highest reliability coefficients contained items from multiple codes, namely alcohol effects and drink count. Self-report alcohol-impaired driving measures with multiple items evaluating distinct aspects of alcohol-impaired driving show better reliability than measures using a single item. Future work investigating the validity of these measures is needed to determine the best approach for conducting self-report research in this area.

Value network and firm performance: the role of knowledge distance and environmental uncertainty

PurposeThis study aims to empirically examine the relationships among perceived environmental uncertainty (EV), the level of knowledge distance (KD) and the impact of value network on firm performance.Design/methodology/approachThe quantitative analysis is based on data from 243 Chinese companies with engineering, procurement and construction (EPC) business in the context of the COVID-19 pandemic.FindingsThe two dimensions of value network [network centrality (NC) and network openness (NO)] have a different impact on firm performance [financial performance (FP) and market performance (MP)]. NC has a positive impact on FP, but not on MP. NO has a positive effect on MP, but not on FP. A reduced KD mediates the relationship between value network and firm performance. Moreover, it fully mediates the relationship between NC and MP, NO and FP. Finally, during the COVID-19 pandemic, only EV has a moderating effect on KD and MP.Research limitations/implicationsThis study is limited in terms of data set because it relies on a limited amount of cross-sectional data from one specific country. Therefore, researchers are encouraged to test the proposed propositions further.Practical implicationsThe present findings suggest that EPC professionals should pay more attention to the EV, which may be impacted by policy, technology and the economy. This research has actionable implications for the reform of EPC in the construction industry, and practical recommendations for EPC firms to improve their corporate performance.Originality/valueThe results measure the complementary effects of both dimensions of value network (NC and NO) on two distinct aspects of firm performance (MP and FP) and assess the moderating effect of EV and KD in the context of the COVID-19 pandemics.

Spatiotemporally distributed frontotemporal networks for sentence reading.

Reading a sentence entails integrating the meanings of individual words to infer more complex, higher-order meaning. This highly rapid and complex human behavior is known to engage the inferior frontal gyrus (IFG) and middle temporal gyrus (MTG) in the language-dominant hemisphere, yet whether there are distinct contributions of these regions to sentence reading is still unclear. To probe these neural spatiotemporal dynamics, we used direct intracranial recordings to measure neural activity while reading sentences, meaning-deficient Jabberwocky sentences, and lists of words or pseudowords. We isolated two functionally and spatiotemporally distinct frontotemporal networks, each sensitive to distinct aspects of word and sentence composition. The first distributed network engages the IFG and MTG, with IFG activity preceding MTG. Activity in this network ramps up over the duration of a sentence and is reduced or absent during Jabberwocky and word lists, implying its role in the derivation of sentence-level meaning. The second network engages the superior temporal gyrus and the IFG, with temporal responses leading those in frontal lobe, and shows greater activation for each word in a list than those in sentences, suggesting that sentential context enables greater efficiency in the lexical and/or phonological processing of individual words. These adjacent, yet spatiotemporally dissociable neural mechanisms for word- and sentence-level processes shed light on the richly layered semantic networks that enable us to fluently read. These results imply distributed, dynamic computation across the frontotemporal language network rather than a clear dichotomy between the contributions of frontal and temporal structures.

Single neurons in the human medial temporal lobe flexibly shift representations across spatial and memory tasks.

Investigations into how individual neurons encode behavioral variables of interest have revealed specific representations in single neurons, such as place and object cells, as well as a wide range of cells with conjunctive encodings or mixed selectivity. However, as most experiments examine neural activity within individual tasks, it is currently unclear if and how neural representations change across different task contexts. Within this discussion, the medial temporal lobe is particularly salient, as it is known to be important for multiple behaviors including spatial navigation and memory, however the relationship between these functions is currently unclear. Here, to investigate how representations in single neurons vary across different task contexts in the medial temporal lobe, we collected and analyzed single-neuron activity from human participants as they completed a paired-task session consisting of a passive-viewing visual working memory and a spatial navigation and memory task. Five patients contributed 22 paired-task sessions, which were spike sorted together to allow for the same putative single neurons to be compared between the different tasks. Within each task, we replicated concept-related activations in the working memory task, as well as target-location and serial-position responsive cells in the navigation task. When comparing neuronal activity between tasks, we first established that a significant number of neurons maintained the same kind of representation, responding to stimuli presentations across tasks. Further, we found cells that changed the nature of their representation across tasks, including a significant number of cells that were stimulus responsive in the working memory task that responded to serial position in the spatial task. Overall, our results support a flexible encoding of multiple, distinct aspects of different tasks by single neurons in the human medial temporal lobe, whereby some individual neurons change the nature of their feature coding between task contexts.

Validation of the Comprehensive Inventory of Mindfulness Experiences (CHIME) in English Using Rasch Methodology

ObjectivesAlthough mindfulness has been studied for multiple decades, psychometric research has yet to agree upon the optimal way to measure the mindfulness construct. Prior research has identified eight distinct aspects of mindfulness that were not adequately captured by any of the available measures. Hence, the Comprehensive Inventory of Mindfulness Experiences (CHIME) was developed. The CHIME contains 37 items and was originally developed in the German language. The CHIME has demonstrated excellent psychometric properties in both German and Dutch, but so far, no English version has been validated. The purpose of the present study was to investigate the psychometric characteristics of the translated English-language CHIME scale using Rasch methodology.MethodThe current study utilized Partial Credit Rasch analysis to evaluate the psychometric characteristics of the English CHIME. The sample included responses from 620 participants from the general population residing in the USA. The validity of the English CHIME was examined by correlating its scores with various measures of mindfulness and psychological functioning.ResultsInitial Rasch analysis of the English CHIME showed poor model fit, local dependency, and evidence against the assumption of unidimensionality. Several minor modifications, that involved creating super-items, were required to fit the Rasch model (χ2(45)=31.99, p=0.93). This model displayed evidence of unidimensionality, invariance across personal factors, and a high reliability (PSI=0.92). Ordinal-interval transformation tables were produced, which increase the English CHIME’s precision of measurement. The English CHIME’s external validity was established by moderate–high correlations with other measures of mindfulness and various measures of psychological functioning.ConclusionsThe results of this study provide evidence for the validity of the English CHIME scale, which can be used to assess the overarching construct of mindfulness.

The importance of theory at the Information Systems Journal

The importance of theory at the <i>Information Systems Journal</i>

D-Dimer Level Associated with Amount of Sinus involvement Using Digital Subtraction Angiography on Cerebral Venous Thrombosis Patients.

Cerebral venous sinus thrombosis (CVST) is a form of the cerebrovascular disease characterized by varying degrees of obstruction of veins and cerebral sinuses caused by thrombus. Diagnosis is incredibly challenging due to the wide variety of symptoms and the distinct radiological aspects of affected vessels. In patients with venous thrombosis, the presence of D-Dimer is used as an indicator of the presence of endogenous fibrinolysis. D-Dimer is a by-product of fibrin polymer fragmentation. To investigate the relationship between the level of D-Dimer and the number of sinuses in CVST by Digital Subtraction Angiography (DSA). Retrospective data from September 2021 to September 2022 were used in this analytical observational with a cross-sectional study design. Chi-Square is used for data processing relationship analysis. Out of the 54 subjects with elevated levels of D-Dimer, 38 (70.4%) are females, whereas 16 (29.6%) are males. High levels of D-Dimer have been related to a greater risk of sinus thrombosis (p < 0.001). D-Dimer levels were similarly shown to rise in conjunction with the number of sinuses most severely damaged by thrombosis. The most common site for thrombosis to develop in this study were the left sigmoid and left transverse sinuses. Most risk factors were hormonal. There is a statistically significant relationship between an increase in the D-Dimer level and the greater number of sinuses involved as determined by DSA in individuals diagnosed with CVST.

Different aspects of hand grip performance associated with structural connectivity of distinct sensorimotor networks in chronic stroke.

Knowledge regarding the neural origins of distinct upper extremity impairments may guide the choice of interventions to target neural structures responsible for specific impairments. This cross-sectional pilot study investigated whether different brain networks explain distinct aspects of hand grip performance in stroke survivors. In 22 chronic stroke survivors, hand grip performance was characterized as grip strength, reaction, relaxation times, and control of grip force magnitude and direction. In addition, their brain structural connectomes were constructed from diffusion tensor MRI. Prominent networks were identified based on a two-step factor analysis using the number of streamlines among brain regions relevant to sensorimotor function. We used regression models to estimate the predictive value of sensorimotor network connectivity for hand grip performance measures while controlling for stroke lesion volumes. Each hand grip performance measure correlated with the connectivity of distinct brain sensorimotor networks. These results suggest that different brain networks may be responsible for different aspects of hand grip performance, which leads to varying clinical presentations of upper extremity impairment following stroke. Understanding the brain network correlates for different hand grip performances may facilitate the development of personalized rehabilitation interventions to directly target the responsible brain network for specific impairments in individual patients, thus improving outcomes.

Effects of cognitive and social demands on linguistic production for people with moderate, mild, or no aphasia

ABSTRACT Background Most everyday communication occurs in situations where cognitive and social demands are present. These types of situations may compound language deficits for people with aphasia (PWA). An understanding of the language interference that may occur from cognitive and social demands is an important precursor for assessment and intervention that addresses everyday communication situations. Aims To determine how cognitively and socially demanding conditions affect micro- and macrolinguistic production for people with moderate, mild, or no aphasia during narrative discourse and to compare effects among groups. Method Thirty participants with mild (n = 9), moderate (n = 9), or no (n = 12) aphasia completed story-retell tasks in three separate conditions: baseline, unresponsive partner, and dual-task. The stories and conditions were pseudorandomly presented for each participant. A secondary analysis investigated lexical, morphosyntactic, and macrolinguistic production. Results As expected, when compared with baseline, the dual-task condition interfered more with language production than the unresponsive partner condition for all participant groups. Interference on distinct aspects of language production for each participant group, however, was not anticipated. This interference was characterized by significant dual-task costs on (a) macrolinguistic production for participants with moderate aphasia, (b) word productivity and lexical diversity for participants with mild aphasia, and (c) lexical-phonological errors for participants with no aphasia. When compared with baseline, the unresponsive partner led to numerical interference on the same measure and group combinations as the dual-task, but these changes were not statistically significant. Conclusions Cognitive and social demands have different effects on language depending on the presence and severity of aphasia with cognitive demands impacting discourse-level structures for participants with moderate aphasia, lexical-level structures for participants with mild aphasia, and lexical-phonological errors for participants with no aphasia. Future research should identify how these demands could be integrated with assessment and treatment for PWA to help improve everyday communication participation.

Elaboration of parents' schemas of their children: Unique relations to sensitivity and learning support among families living in poverty.

This study examined how distinct aspects of parents' schemas of their children are related to caregiving behaviors. It included 242 families with toddlers and young children, most of whom were living in poverty (37% White, 25% Black, 19% Latine, 17% Multiracial, and 2% Asian; child age = 21-39 months; median family income = $1,555 per month). The elaboration and emotional valence of parents' schemas were coded from brief responses to open-ended questions about children's personality; observations of parents' sensitivity and learning support were assessed in structured and unstructured settings. Results of regression equations controlling for multiple family, parent, and child characteristics revealed that both greater elaboration and positive emotional valence were uniquely related to parents' sensitivity (standardized β = .15, p = .05, and β = .13, p = .04, respectively), but only elaboration was uniquely related to learning support (β = .35, p < .001). This study highlights the special importance of the elaboration of parents' schemas in understanding caregiving behaviors among families living in poverty and the potential value of enhancing elaboration in family-focused preventive interventions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

TIAR and FMRP shape pro-survival nascent proteome of leukemia cells in the bone marrow microenvironment

Chronic myeloid leukemia (CML) cells circulate between blood and bone marrow niche, representing different microenvironments. We studied the role of the two RNA-binding proteins, T-cell-restricted intracellular antigen (TIAR), and the fragile X mental retardation protein (FMRP) in the regulation of protein translation in CML cells residing in settings mimicking peripheral blood microenvironment (PBM) and bone marrow microenvironment (BMM). The outcomes showed how conditions shaped the translation process through TIAR and FMRP activity, considering its relevance in therapy resistance. The QuaNCAT mass-spectrometric approach revealed that TIAR and FMRP have a discrete modulatory effect on protein synthesis and thus affect distinct aspects of leukemic cells functioning in the hypoxic niche. In the BMM setup, FMRP impacted metabolic adaptation of cells and TIAR substantially supported the resistance of CML cells to translation inhibition by homoharringtonine. Overall, our results demonstrated that targeting post-transcriptional control should be considered when designing anti-leukemia therapeutic solutions.

Literary studies of political caricature: a quantitative analysis of publications indexed in the Scopus

The author reviews the past-to-present academic literature on cartoon studies (mainly editorial and political cartoons), that reflects the functional crisis of the cartoon associated with the development of the media space and new challenges. Some of the main trends, taxonomies, and approaches to date in political cartoon research are shown, and some of the weaknesses and strengths in the present field as well as aspects that are underdeveloped or have yet to be explored are highlighted. The articles in English published between 2017 and 2022 were reviewed to provide an understanding of the current state of the matter in various areas. The corpus was gathered by searching publications in international database Scopus. Each paper was classified based on its publication date, place of origin, subject of research, and frequency of citations. The quantitative approach employed enables the tracking of advancement in the field of cartoon studies over a given timeframe. Six distinct aspects pertinent to research in the field of political cartoons are suggested in a holistic approach, although this categorization is by no means all-inclusive and there is substantial overlap. The study of political cartoons during chosen period was more comprehensive and extensive than the study of editorial cartoons. Several proposals for further research in this field were put forward.

Internal corporate social responsibility and customer-oriented organizational citizenship behavior: the mediating roles of job satisfaction, work-family facilitation, life satisfaction, and the moderating role of organizational tenure

Drawing on social exchange theory, this study examines the relationship between internal corporate social responsibility (CSR) and hospitality employees’ customer-oriented organizational citizenship behavior (CO-OCB). The role of three distinct aspects (work, family, and life aspects) function as parallel mediating mechanisms, with organizational tenure as a moderator. The sample consisted of 156 flight attendants working in airlines based in Asian countries. The findings show that internal CSR (i.e., legal employment, training, internal dissemination, compensation, health and safety) promotes CO-OCB. Job satisfaction and work-family facilitation (WFF) partially mediate the positive relationship between internal CSR and CO-OCB, whereas life satisfaction does not serve the same function. The multiple mediation findings indicate that in stimulating flight attendants’ CO-OCB, WFF accounts for more effects of internal CSR than job satisfaction does. Findings also suggest that the impact of internal CSR on CO-OCB is more pronounced among long-tenured than short-tenured employees. This study broadens the tourism literature by advancing our comprehension of not only the multiple mediating mechanisms involved but also the boundary conditions that influence the impact of internal CSR on CO-OCB.

Immunocal® limits gliosis in mouse models of repetitive mild-moderate traumatic brain injury

Successive traumatic brain injuries (TBIs) exacerbate neuroinflammation and oxidative stress. No therapeutics exist for populations at high risk of repetitive mild TBIs (rmTBIs). We explored the preventative therapeutic effects of Immunocal®, a cysteine-rich whey protein supplement and glutathione (GSH) precursor, following rmTBI and repetitive mild-moderate TBI (rmmTBI). Populations that suffer rmTBIs largely go undiagnosed and untreated; therefore, we first examined the potential therapeutic effect of Immunocal® long-term following rmTBI. Mice were treated with Immunocal® prior to, during, and following rmTBI induced by controlled cortical impact until analysis at 2 weeks, 2 months, and 6 months following the last rmTBI. Astrogliosis and microgliosis were measured in cortex at each time point and edema and macrophage infiltration by MRI were analyzed at 2 months post-rmTBI. Immunocal® significantly reduced astrogliosis at 2 weeks and 2 months post-rmTBI. Macrophage activation was observed at 2 months post-rmTBI but Immunocal® had no significant effect on this endpoint. We did not observe significant microgliosis or edema after rmTBI. The dosing regimen was repeated in mice subjected to rmmTBI; however, using this experimental paradigm, we examined the preventative therapeutic effects of Immunocal® at a much earlier timepoint because populations that suffer more severe rmmTBIs are more likely to receive acute diagnosis and treatment. Increases in astrogliosis, microgliosis, and serum neurofilament light (NfL), as well as reductions in the GSH:GSSG ratio, were observed 72 h post-rmmTBI. Immunocal® only significantly reduced microgliosis after rmmTBI. In summary, we report that astrogliosis persists for 2 months post-rmTBI and that inflammation, neuronal damage, and altered redox homeostasis present acutely following rmmTBI. Immunocal® significantly limited gliosis in these models; however, its neuroprotection was partially overwhelmed by repetitive injury. Treatments that modulate distinct aspects of TBI pathophysiology, used in combination with GSH precursors like Immunocal®, may show more protection in these repetitive TBI models.

On the Question of Formation and Development of the Animation Industry in the XX — Beginning of XXI Century

The purpose of the article is to analyze distinct aspects of the formation and development of the animation industry during XX — at the beginning of XXI century in connection with the movie industry and broadcasting mainly in the USA that allows a deep understanding of the essence and peculiarities of audiovisual industry functioning as the separate segment of creative industry.&#x0D; The methodology. On the basis of the historical approach and also methods of data collecting and analytical and synthetical processing, qualitative analysis of development was conducted. It was found out that today the animation industry is a separate segment of audiovisual industry, that had overcome a difficult way of development in co-evolution with the movie and TV industries that have survived in the globalization of production and its distribution.&#x0D; The results. The industry of animation appeared in the USA under the influence of cinematography and its further formation was determined by two main factors: technological development that enabled diversified markets and products, improved animators’ ability to express their own creative ideas, besides, assisted to enlarge the global market and many regional market niches, and also the tendency of cost decrease of production that provided the basic conditions for the animation production in other countries-subcontractors. &#x0D; After the World War II a sharp drop in showing animated cartoons in the cinema was observed but with the appearance and spreading of TV for the animated industry new possibilities became available. Significant changes happened in 1980 when after almost a decade break, 2D animated films were actively made for the cinemas, and within the animated industry two measurements were formed — local-artisanal and global Hollywood system. Technological determinism brought new markets and two tendencies into animated production: mass production for the non-theatrical markets, CGI in the world market. Using cheap software and fast rendering of CGI-animation have changed forever the TV animation and had a huge influence on the geography of the animated industry.&#x0D; The scientific novelty. Analysis of the animation through the prism of branch industrialization during XX — beginning XXI century.&#x0D; The practical significance. The material of the given article can be used for the development of program or strategies for the animated industry development in Ukraine as a foreign experience.

Proteomics and transcriptomics profiling reveals distinct aspects of kidney stone related genes in calculi rats

BackgroundsKidney stone also known as urolithiasis or nephrolithiasis, is one of the oldest diseases known to medicine, however, the gene expression changes and related kidney injury remains unclear. MethodsA calculi rat model was developed via ethylene glycol– and ammonium chloride–induction. Integrated proteomic and transcriptomic analysis was performed to characterize the distinct gene expression profiles in the kidney of calculi rat. Differential expressed genes (DEGs) were sub-clustered into distinct groups according to the consistency of transcriptome and proteome. Gene Ontology and KEGG pathway enrichment was performed to analyze the functions of each sub-group of DEGs. Immunohistochemistry was performed to validated the expression of identified proteins.ResultsFive thousand eight hundred ninety-seven genes were quantified at both transcriptome and proteome levels, and six distinct gene clusters were identified, of which 14 genes were consistently dysregulated. Functional enrichment analysis showed that the calculi rat kidney was increased expression of injured & apoptotic markers and immune-molecules, and decreased expression of solute carriers & transporters and many metabolic related factors.ConclusionsThe present proteotranscriptomic study provided a data resource and new insights for better understanding of the pathogenesis of nephrolithiasis, will hopefully facilitate the future development of new strategies for the recurrence prevention and treatment in patients with kidney stone disease.

Hippocampal Noradrenaline Is a Positive Regulator of Spatial Working Memory and Neurogenesis in the Rat

Loss of noradrenaline (NA)-rich afferents from the Locus Coeruleus (LC) ascending to the hippocampal formation has been reported to dramatically affect distinct aspects of cognitive function, in addition to reducing the proliferation of neural progenitors in the dentate gyrus. Here, the hypothesis that reinstating hippocampal noradrenergic neurotransmission with transplanted LC-derived neuroblasts would concurrently normalize both cognitive performance and adult hippocampal neurogenesis was investigated. Post-natal day (PD) 4 rats underwent selective immunolesioning of hippocampal noradrenergic afferents followed, 4 days later, by the bilateral intrahippocampal implantation of LC noradrenergic-rich or control cerebellar (CBL) neuroblasts. Starting from 4 weeks and up to about 9 months post-surgery, sensory-motor and spatial navigation abilities were evaluated, followed by post-mortem semiquantitative tissue analyses. All animals in the Control, Lesion, Noradrenergic Transplant and Control CBL Transplant groups exhibited normal sensory-motor function and were equally efficient in the reference memory version of the water maze task. By contrast, working memory abilities were seen to be consistently impaired in the Lesion-only and Control CBL-Transplanted rats, which also exhibited a virtually complete noradrenergic fiber depletion and a significant 62-65% reduction in proliferating 5-bromo-2'deoxyuridine (BrdU)-positive progenitors in the dentate gyrus. Notably, the noradrenergic reinnervation promoted by the grafted LC, but not cerebellar neuroblasts, significantly ameliorated working memory performance and reinstated a fairly normal density of proliferating progenitors. Thus, LC-derived noradrenergic inputs may act as positive regulators of hippocampus-dependent spatial working memory possibly via the concurrent maintenance of normal progenitor proliferation in the dentate gyrus.