Subsequent Interference Research Articles

Positive affect and pain: mediators of the within-day relation linking sleep quality to activity interference in fibromyalgia.

Fibromyalgia (FM) is a chronic pain condition often resulting in functional impairments. Nonrestorative sleep is a prominent symptom of FM that is related to disability, but the day-to-day mechanisms relating the prior night's sleep quality to next-day reports of disability have not been examined. This study examined the within-day relations among early-morning reports of sleep quality last night, late-morning reports of pain and positive and negative affect, and end-of-day reports of activity interference. Specifically, we tested whether pain, positive affect, and negative affect mediated the association between sleep quality and subsequent activity interference. Data were drawn from electronic diary reports collected from 220 patients with FM for 21 consecutive days. The direct and mediated effects at the within-person level were estimated with multilevel structural equation modeling. Results showed that pain and positive affect mediated the relation between sleep quality and activity interference. Early-morning reports of poor sleep quality last night predicted elevated levels of pain and lower levels of positive affect at late-morning, which, in turn, predicted elevated end-of-day activity interference. Of note, positive affect was a stronger mediator than pain and negative affect was not a significant mediator. In summary, the findings identify 2 parallel mechanisms, pain and positive affect, through which the prior night's sleep quality predicts disability the next day in patients with FM. Furthermore, results highlight the potential utility of boosting positive affect after a poor night's sleep as one means of preserving daily function in FM.

Retrieval practice does not safeguard memories from interference-based forgetting

Retrieval enhances long-term retention. However, reactivation of a memory also renders it susceptible to modifications as shown by studies on memory reconsolidation. The present study explored whether retrieval diminishes or enhances subsequent retroactive interference (RI) and intrusions. Participants learned a list of objects. Two days later, they were either asked to recall the objects, given a subtle reminder, or were not reminded of the first learning session. Then, participants learned a second list of objects or performed a distractor task. After another two days, retention of List 1 was tested. Although retrieval enhanced List 1 memory, learning a second list impaired memory in all conditions. This shows that testing did not protect memory from RI. While a subtle reminder before List 2 learning caused List 2 items to later intrude into List 1 recall, very few such intrusions were observed in the testing and the no reminder conditions. The findings are discussed in reference to the reconsolidation account and the testing effect literature, and implications for educational practice are outlined.

The search for mass graves of the soldiers of the National Armed Forces murdered in September 1946 in the Opole region of Poland - results of forensic medical examination.

The aim of the study is the identification and forensic-medical and anthropological evaluation of the remains of soldiers of the National Armed Forces murdered by the secret police in September 1946 in the Opole region. The remains were located during the search for mass graves of victims of the Communist regime carried out by the Institute of National Remembrance (IPN). In June 2012 and April 2013, in the area of the Hubertus clearing between the villages of Barut and Dąbrówka, 41 human bone fragments were revealed in the course of archaeological works carried with use of the open pit method at the probable site of the liquidation of one of the groups of soldiers from the unit of Captain Henryk Flame, aka "Bartek". In the vicinity of the ruins of the former Scharfenberg manor, in a forest of the Łambinowice commune, a mass grave was discovered containing the remains of at least 25 individuals, mostly young men. The grave was damaged and bore traces of subsequent interference. The forensic-medical-anthropological examination procedures were carried out, the biological profile of the victims evaluated, the minimum number of individuals (MNI) determined and the injuries interpreted. A portion of the remains discovered near the village of Barut bore traces of trauma associated with a great force. On the remains from the mass grave in the Łambinowice commune, numerous traces of injuries of the perimortem trauma nature were disclosed, including gunshot damage, both within the skulls and in post-cranial skeletons. The activity of the Institute of National Remembrance led to the confirmation of archival data regarding the site of liquidation of one of the partisan groups of the National Armed Forces in the vicinity of the village of Barut in the Opole region. The research did not allow unambiguous determination of the origin of remains discovered in the mass grave in the Łambinowice commune. The archival data indicate that the remains may be those of victims of Communist terror.

Sleep-dependent memory consolidation and neurofeedback in insomnia - A long-term study

Event Abstract Back to Event Sleep-dependent memory consolidation and neurofeedback in insomnia - A long-term study Manuel Schabus1, 2*, Hermann Griessenberger3, Dominik Heib3, Daniel Koerner3 and Kerstin Hoedlmoser2, 4 1 University of Salzburg, Department of Psychology, Austria 2 University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria 3 University of Salzburg, Austria 4 University of Salzburg, Department of Psychology, Austria The suggested functions of sleep are manifold, involving adaptive strategies, physical recovery and more recently "offline" information reprocessing. Here we now present a study in which the same type of declarative (word-pair learning) and procedural (finger-tapping) task was conducted four times (weeks apart) in the evening with subsequent interference manipulation the next morning in insomnia patients. In addition 36 healthy controls spend 3 nights in the laboratory to test for (healthy) sleep-dependent memory consolidation. In addition, 12-15Hz (sensorimotor rhythm; SMR) as well as placebo "neurofeedback" was conducted in the insomnia group. With respect to the susceptibility to interference it becomes evident that interference affects the declarative memory domain much more than the procedural one. Forgetting from initial evening learning to a delayed recall after a week (as well as after interference) is also found more pronounced in insomnia patients than healthy controls. Analyses of the sleep EEG and sleep spindles reveal a trait-like relationship between fast spindle activity (SpA) and (i) the initial learning levels in the declarative memory as well as (ii) an association with the declarative overnight memory change. Last but not least our double-blind neurofeedback protocol indicates that patients suffering from insomnia are able to enhance SMR-power and (fast) sleep spindles over the 12 SMR training sessions. Yet direct benefits for sleep quality or memory consolidation were not observed, rather the subjective sleep complaint decreased unspecifically across both conditions. Current results indicate that healthy as well as insomnia patients do show associations of (overnight) memory performance and (fast) sleep spindle activity and interestingly are even able to increase these spindles by means of instrumental 12-15Hz EEG conditioning. Research was supported by FWF research grants (P-21154-B18; I-934) from the Austrian Science Foundation. Keywords: Memory, Neurofeedback, Sleep, insomnia, consolidation Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Memory and Learning Citation: Schabus M, Griessenberger H, Heib D, Koerner D and Hoedlmoser K (2015). Sleep-dependent memory consolidation and neurofeedback in insomnia - A long-term study. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00365 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Dr. Manuel Schabus, University of Salzburg, Department of Psychology, Salzburg, Austria, manuel.schabus@sbg.ac.at Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Manuel Schabus Hermann Griessenberger Dominik Heib Daniel Koerner Kerstin Hoedlmoser Google Manuel Schabus Hermann Griessenberger Dominik Heib Daniel Koerner Kerstin Hoedlmoser Google Scholar Manuel Schabus Hermann Griessenberger Dominik Heib Daniel Koerner Kerstin Hoedlmoser PubMed Manuel Schabus Hermann Griessenberger Dominik Heib Daniel Koerner Kerstin Hoedlmoser Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

REM sleep rescues learning from interference

Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost.

Identification of differentially expressed genes in the pheromone glands of mated and virgin Bombyx mori by digital gene expression profiling.

BackgroundMating decreases female receptivity and terminates sex pheromone production in moths. Although significant progress has been made in elucidating the mating-regulated inactivation of pheromone biosynthesis-activating neuropeptide (PBAN) secretion, little is known about the mating induced gene expression profiles in pheromone glands (PGs). In this study, the associated genes involved in Bombyx mori mating were identified through digital gene expression (DGE) profiling and subsequent RNA interference (RNAi) to elucidate the molecular mechanisms underlying the mating-regulated gene expression in PGs.ResultsEight DGE libraries were constructed from the PGs of mated and virgin females: 1 h mating (M1)/virgin (V1) PGs, 3 h mating (M3)/virgin (V3) PGs, 24 h mating (M24)/virgin (V24) PGs and 48 h mating (M48)/virgin (V48) PGs (M48 and V48). These libraries were used to investigate the gene expression profiles affected by mating. DGE profiling revealed a series of genes showing differential expression in each set of mated and virgin female samples, including immune-associated genes, sex pheromone synthesis-associated genes, juvenile hormone (JH) signal-associated genes, etc. Most interestingly, JH signal was found to be activated by mating. Application of the JH mimics, methoprene to the newly-emerged virgin females leaded to the significant reduction of sex pheromone production. RNAi-mediated knockdown of putative JH receptor gene, Methoprene tolerant 1 (Met1), in female pupa resulted in a significant decrease in sex pheromone production in mature females, suggesting the importance of JH in sex pheromone synthesis.ConclusionA series of differentially expressed genes in PGs in response to mating was identified. This study improves our understanding of the role of JH signaling on the mating-elicited termination of sex pheromone production.

Determination of collagen fibril size via absolute measurements of second-harmonic generation signals.

The quantification of collagen fibril size is a major issue for the investigation of pathological disorders associated with structural defects of the extracellular matrix. Second-harmonic generation microscopy is a powerful technique to characterize the macromolecular organization of collagen in unstained biological tissues. Nevertheless, due to the complex coherent building of this nonlinear optical signal, it has never been used to measure fibril diameter so far. Here we report absolute measurements of second-harmonic signals from isolated fibrils down to 30 nm diameter, via implementation of correlative second-harmonic-electron microscopy. Moreover, using analytical and numerical calculations, we demonstrate that the high sensitivity of this technique originates from the parallel alignment of collagen triple helices within fibrils and the subsequent constructive interferences of second-harmonic radiations. Finally, we use these absolute measurements as a calibration for ex vivo quantification of fibril diameter in the Descemet's membrane of a diabetic rat cornea.

High Seed Retention at Maturity of Annual Weeds Infesting Crop Fields Highlights the Potential for Harvest Weed Seed Control

Seed production of annual weeds persisting through cropping phases replenishes/establishes viable seed banks from which these weeds will continue to interfere with crop production. Harvest weed seed control (HWSC) systems are now viewed as an effective means of interrupting this process by targeting mature weed seed, preventing seed bank inputs. However, the efficacy of these systems is directly related to the proportion of total seed production that the targeted weed species retains (seed retention) at crop maturity. This study determined the seed retention of the four dominant annual weeds of Australian cropping systems - annual ryegrass, wild radish, brome grass, and wild oat. Beginning at the first opportunity for wheat harvest and on a weekly basis for 28 d afterwards the proportion of total seed production retained above a 15 cm harvest cutting height was determined for these weed species present in wheat crops at nine locations across the Western Australian (WA) wheat-belt. Very high proportions of total seed production were retained at wheat crop maturity for annual ryegrass (85%), wild radish (99%), brome grass (77%), and wild oat (84%). Importantly, seed retention remained high for annual ryegrass and wild radish throughout the 28 d harvest period. At the end of this period, 63 and 79% of total seed production for annual ryegrass and wild radish respectively, was retained above harvest cutting height. However, seed retention for brome grass (41%) and wild oat (39%) was substantially lower after 28 d. High seed retention at crop maturity, as identified here, clearly indicates the potential for HWSC systems to reduce seed bank replenishment and diminish subsequent crop interference by the four most problematic species of Australian crops.

Dual-task backward compatibility effects are episodically mediated.

In dual-task performance, the backward compatibility effect (BCE; faster Task 1 reaction time when Task 1 and Task 2 responses are compatible) is thought to represent automatic activation of Task 2 response information in parallel with attended Task 1 performance. Work by Hommel and Eglau (Psychological Research, 66, 260-273, 2002) has suggested the BCE relies on stimulus-response learning in long-term memory. Subsequent work by Ellenbogen and Meiran (Memory and Cognition, 36, 968-978, 2008), however, proposed that the BCE is mediated by Task 2 rules held in working memory (WM) during Task 1 performance. The present study aimed to dissociate these two theoretical claims. In Experiment 1, we assessed the effects of prior single-task practice with Task 1 or Task 2 of a subsequent dual-task paradigm. Where the WM-mediated model predicts both BCE and overall reaction time improvement relative to prior task practice, an episodic learning model makes divergent predictions for BCE based on the context specificity of prior Task 2 learning. Results showed a close fit with episodic predictions and contradicted WM model predictions. Experiment 2 examined the finer grained timecourse of BCE over initial development, subsequent interference of this initial learning on BCE development with new conflicting Task 2 response mappings, and finally reestablishment of BCE in the original dual task. Data again showed close agreement with long-term learning predictions. We argue in favor of an episodic account of the BCE, and consider implications of WM and episodic mechanisms of automatic response activation on other aspects of dual-task performance.

A republican account of the value of privacy

This article provides an account of the value of privacy in securing the republican aims of self-government and conditions of non-domination. It describes how loss of privacy might lead to subjugation to dominating power. The republican concept of domination provides the foundation of a broad and coherent account of the value of privacy. One that encompasses circumstances in which the subject (i) suffers interference as a result of the loss, (ii) is aware that he has suffered a loss of privacy, but suffers no subsequent interference and (iii) is unaware that he has suffered any loss of privacy, and suffers no subsequent interference. Liberal accounts explain the value of privacy in the first two circumstances by pointing to the possible effect of the loss on the autonomy of the subject, but because they focus on autonomy are unable to explain why privacy is valuable where an agent is unaware of the loss. The republican account provided here explains why loss is harmful in all three circumstances. The final part of the article argues that because privacy is a pre-requisite for effective participation in political life, and republicans consider such participation to be the essence of self-government and the means through which a polity can secure conditions of freedom, in a republican democracy individual privacy will be seen as a collective good.

Haloarcula hispanica CRISPR authenticates PAM of a target sequence to prime discriminative adaptation.

The prokaryotic immune system CRISPR/Cas (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated genes) adapts to foreign invaders by acquiring their short deoxyribonucleic acid (DNA) fragments as spacers, which guide subsequent interference to foreign nucleic acids based on sequence matching. The adaptation mechanism avoiding acquiring ‘self’ DNA fragments is poorly understood. In Haloarcula hispanica, we previously showed that CRISPR adaptation requires being primed by a pre-existing spacer partially matching the invader DNA. Here, we further demonstrate that flanking a fully-matched target sequence, a functional PAM (protospacer adjacent motif) is still required to prime adaptation. Interestingly, interference utilizes only four PAM sequences, whereas adaptation-priming tolerates as many as 23 PAM sequences. This relaxed PAM selectivity explains how adaptation-priming maximizes its tolerance of PAM mutations (that escape interference) while avoiding mis-targeting the spacer DNA within CRISPR locus. We propose that the primed adaptation, which hitches and cooperates with the interference pathway, distinguishes target from non-target by CRISPR ribonucleic acid guidance and PAM recognition.

Iron mapping using the temperature dependency of the magnetic susceptibility.

The assessment of iron content in brain white matter (WM) is of high importance for studying neurodegenerative diseases. While R2 * mapping and quantitative susceptibility mapping is suitable for iron mapping in gray matter, iron mapping in WM still remains an unsolved problem. We propose a new approach for iron mapping, independent of diamagnetic contributions of myelin by assessing the temperature dependency of the paramagnetic susceptibility. We used unfixed human brain slices for relaxometry and calculated R2 ' as a measure for microscopic susceptibility variations at several temperatures (4°C-37°C) at 3 Tesla. The temperature coefficient of R2 ' (TcR2p) was calculated by linear regression and related to the iron concentration found by subsequent superconducting quantum interference device (SQUID) magnetometry and by inductively coupled plasma mass spectrometry. In line with SQUID measurements, R2 ' mapping showed a linear temperature dependency of the bulk susceptibility with the highest slope in gray matter. Even in WM, TcR2p yielded a high linear correlation with the absolute iron concentration. According to Curie's law, only paramagnetic matter exhibits a temperature dependency while the diamagnetism shows no effect. We have demonstrated that the temperature coefficient (TcR2p) can be used as a measure of the paramagnetic susceptibility despite of an unknown diamagnetic background.

Simulating the impacts of land-use change on a large-scale runoff using the easy distributed hydrological model

This study introduces a simulation method to identify large-scale land-use parameters that can be used to directly assess how changes in land use affect the generation of runoff. The study examined data during the flood seasons for the Second Songhua River basin, located in the northeast China. The Easy distributed hydrological model was modified to simulate the rainfall–runoff processes of different land-use types. Input data comprised land-use data during a period of minimal human activity and also under subsequent human interference. Time-scale validation and spatial validation both confirmed the suitability of the model for the study area and the feasibility of transferring land-use parameters. Runoff generation per unit area was calculated for each land-use type, and was found to descend in such order: water surface > residential area > unused land > cultivated land > woodland > grassland.

A matter of time: rapid motor memory stabilization in childhood

Are children better than adults in acquiring new skills ('how-to' knowledge) because of a difference in skill memory consolidation? Here we tested the proposal that, as opposed to adults, children's memories for newly acquired skills are immune to interference by subsequent experience. The establishment of long-term memory for a trained movement sequence in adults requires a phase of memory consolidation. This results in substantial delayed, 'offline', performance gains, which nevertheless remain susceptible to interference by subsequent competing motor experience for several hours after training, unless sleep is afforded in the interval. Here we compared the gains attained overnight (delayed gains) by 9-year-olds and adults after training on a novel finger-to-thumb movement sequence, with and without subsequent interference by repeating a different movement sequence. Our results show that, in 9-year-olds, but not in adults, an interval of 15 min. between the training session and interfering experience sufficed to ensure the expression of delayed, consolidation phase, gains. Nevertheless, in the 9-year-olds, as well as in adults, the gains attained with no interference were significantly larger. Altogether, our results show that while the behavioral expressions of childhood and adult consolidation processes are similar, procedural memory stabilizes, in the waking state, at a much faster rate in children. We propose that, in children, rapid stabilization is a mechanism whereby the constraints on consolidating new experiences into long-term procedural memory are relaxed at the cost of selectivity.

TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex

In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

The CitizenShield dialogue system in multilingual applications

The present study involves the development of interlinguas (ILTs) as semantic templates for a possible multilingual extension of the CitizenShield dialogue system for consumer complaints. The proposed ‘simple interlinguas’ (S-ILTs) are designed to function within a very restricted sublanguage related to a specific task, but at the same time, for a very diverse range of languages and language families, in an attempt to meet the needs of the diverse community of foreign residents in Greece. The nature of the CitizenShield system’s dialogue structure facilitates the construction of interlinguas (ILTs) designed to comply to the above-described standards. In the sublanguage of the present system, the construction of interlinguas involves the efficient handling of ambiguous expressions related to prosodic features affecting the lexical semantics of words in languages as diverse as Chinese and Greek and the reduction or minimalisation of language-related interference of ambiguities related to verb type and verb structure confronted in languages such as Persian, or phenomena in verb semantics such as ‘multitasking’ verbs or other ‘primitive verbs’ in Greek. Additionally, the simple interlinguas (S-ILTs) are designed to bypass the complex task of processing discourse information and subsequent strong cultural interference from languages as diverse as Arabic and Chinese.

A Republican Account of the Value of Privacy

This article provides an account of the value of privacy in securing the republican aims of self-government and conditions of non-domination. It describes how loss of privacy might lead to subjugation to dominating power. The republican concept of domination provides the foundation of a broad and coherent account of the value of privacy. One that encompasses circumstances in which the subject (i) suffers interference as a result of the loss, (ii) is aware that he has suffered a loss of privacy, but suffers no subsequent interference, and (iii) is unaware that he has suffered any loss of privacy, and suffers no subsequent interference. Liberal accounts explain the value of privacy in the first two circumstances by pointing to the possible effect of the loss on the autonomy of the subject, but because they focus on autonomy are unable to explain why privacy is valuable where an agent is unaware of the loss. The republican account provided here explains why loss is harmful in all three circumstances. The final part of the article argues that because privacy is a pre-requisite for effective participation in political life, and republicans consider such participation to be the essence of self-government and the means through which a polity can secure conditions of freedom, in a republican democracy individual privacy will be seen as a collective good.

Context-dependent sequential effects of target selection for action

Humans exhibit variation in behavior from moment to moment even when performing a simple, repetitive task. Errors are typically followed by cautious responses, minimizing subsequent distractor interference. However, less is known about how variation in the execution of an ultimately correct response affects subsequent behavior. We asked participants to reach toward a uniquely colored target presented among distractors and created two categories to describe participants' responses in correct trials based on analyses of movement trajectories; partial errors referred to trials in which observers initially selected a nontarget for action before redirecting the movement and accurately pointing to the target, and direct movements referred to trials in which the target was directly selected for action. We found that latency to initiate a hand movement was shorter in trials following partial errors compared to trials following direct movements. Furthermore, when the target and distractor colors were repeated, movement time and reach movement curvature toward distractors were greater following partial errors compared to direct movements. Finally, when the colors were repeated, partial errors were more frequent than direct movements following partial-error trials, and direct movements were more frequent following direct-movement trials. The dependence of these latter effects on repeated-task context indicates the involvement of higher-level cognitive mechanisms in an integrated attention-action system in which execution of a partial-error or direct-movement response affects memory representations that bias performance in subsequent trials. Altogether, these results demonstrate that whether a nontarget is selected for action or not has a measurable impact on subsequent behavior.

The protective effects of lactoferrin against murine norovirus infection through inhibition of both viral attachment and replication

The purpose of this study was to evaluate the effects of bovine lactoferrin against norovirus infection using mouse norovirus (MNV) and Raw264.7 cell in vitro. When Raw264.7 cells were infected with MNV in the presence or absence of lactoferrin, the cytotoxic damage to the infected Raw264.7 cells significantly and dose-dependently decreased and completely inhibited in the presence of 15 or 20μg/well of lactoferrin as compared with the absence of lactoferrin. Correspondingly, the MNV titers in the culture medium and intracellularly were significantly decreased in infected Raw264.7 cells treated with lactoferrin compared to control infected Raw264.7 cells. The mechanisms responsible for the protective effects of lactoferrin against MNV infection were attributed to both its inhibition of the initial MNV attachment to cells and the subsequent interference with MNV replication. Moreover, it was revealed that lactoferrin could rapidly induce the expression of anti-viral cytokine mRNA, such as IFN-α and IFN-β which involved in inhibition of MNV replication in infected Raw264.7 cells, in the early phase of infection. It was concluded that lactoferrin exerts protective effects against MNV infection through inhibition of both viral attachment and replication. The present results provide evidence that lactoferrin may be useful as a preventive and/or therapeutic anti-norovirus agent.

Response of Herbicide-Resistant Palmer Amaranth (Amaranthus palmeri) Accessions to Drought Stress

Palmer amaranth is a very problematic weed in several crops in the southern USA due to its competitive ability and resistance to herbicides representing different mechanisms of action. Variation in growth and subsequent interference of North Carolina Palmer amaranth accessions has not been examined. A greenhouse experiment determined response of 15 North Carolina Palmer amaranth accessions to drought stress beginning 15 days after seedling emergence (DAE) for a duration of 3, 5, 7, and 9 days. Following exposure to drought, plants were grown under optimal moisture conditions until harvest at 30 DAE. Five accessions each of glyphosate-resistant (GR), acetolactate synthase inhibitor-resistant (ALSR), and acetolactate synthase inhibitor-susceptible and glyphosate-susceptible (ALSS/GS) were compared. Variation in response to drought stress, based on height and dry weight reduction relative to nonstressed controls, was noted among accessions. Stress for 3 or more days affected height and dry weight. Height and dry weight of GR and ALSR accession groups were reduced less by drought than the ALSS/GS accession group. Results suggest a possible relationship between herbicide resistance and ability of Palmer amaranth to withstand drought stress and thus a possible competitive advantage for resistant accessions under limited moisture availability.