Effects of memory load and distraction on performance and event-related slow potentials in a visuospatial working memory task

Brain electrical activity related to working memory was recorded at 15 scalp electrodes during a visuospatial delayed response task. Participants (N = 18) touched the remembered position of a target on a computer screen after either a 1 or 8 sec delay. These memory trials were compared to sensory trials in which the target remained present throughout the delay and response periods. Distracter stimuli identical to the target were briefly presented during the delay on 30% of trials. Responses were less accurate in memory than sensory trials, especially after the long delay. During the delay slow potentials developed that were significantly more negative in memory than sensory trials. The difference between memory and sensory trials was greater at anterior than posterior electrodes. On trials with distracters, the slow potentials generated by memory trials showed further enhancement of negativity whereas there were minimal effects on accuracy of performance. The results provide evidence that engagement of visuospatial working memory generates slow wave negativity with a timing and distribution consistent with frontal activation. Enhanced brain activity associated with working memory is required to maintain performance in the presence of distraction. © 1997 by the Massachusetts Institute of Technolog

Mutual Fund Sales Notice Fees: Are a Handful of States Unconstitutionally Exacting $200 Million Each Year

This article examines the constitutionality of notice filing fees in six states. Although almost every state requires such fees to be paid by mutual funds, six of these states require fees that are highly disproportional to the amount of shares traded within their states. The filing fees in these states, accounting for 50 percent of the total paid nationwide, are considered as either regulatory fees or state taxes. Regardless of whether these fees are categorized as regulatory fees or state taxes, they are unconstitutional under either the Due Process Clause or Commerce Clause of the Constitution. Not only would these funds be able to potentially recover nearly $600 million taken by these states, the elimination of these annual fees would prospectively save mutual funds between$2 billion and $4 billion

Mutual Fund Sales Notice Fees: Are a Handful of States Unconstitutionally Exacting $200 Million Each Year

This article examines the constitutionality of notice filing fees in six states. Although almost every state requires such fees to be paid by mutual funds, six of these states require fees that are highly disproportional to the amount of shares traded within their states. The filing fees in these states, accounting for 50 percent of the total paid nationwide, are considered as either regulatory fees or state taxes. Regardless of whether these fees are categorized as regulatory fees or state taxes, they are unconstitutional under either the Due Process Clause or Commerce Clause of the Constitution. Not only would these funds be able to potentially recover nearly $600 million taken by these states, the elimination of these annual fees would prospectively save mutual funds between$2 billion and $4 billion

ERP Customer Loyalty: An Exploratory Investigation into the Importance of a Trusting Relationship

ERP customer loyalty toward customization vendors – the customers’ intention to do more business with the customization vendor – is in the clear interest of the customization vendors. This study reports the results of an exploratory online survey among ERP customization customers that examined the relative importance on customer loyalty of the nature of the trusting relationship the ERP customization vendor developed with them. As hypothesized, the more the customers trusted the ERP vendor, the more loyal they were. Trust, as in other services, was more influential than cost in affecting loyalty. Trust itself was strongly influenced by the vendors’ responsiveness and courtesy. The regressions suggest that trust is probably among the most important elements contributing to loyalty (R2= .46), and that responsiveness and courtesy are likely major elements contributing to this trust (R2= .51). Implications for industry and theory are discussed

Applying TAM to a Paralell Systems Conversion Strategy

According to the Technology Acceptance Model (TAM) user perceptions of usefulness and ease of use are major determinants of IT adoption. Extensive research dealing with direct cut over implementation of new IT in field settings support this assertion. In today’s market, however, new IT are often deployed using a parallel systems strategy: new IT are implemented while existing IT are retained so that both IT work in parallel for some time. This study suggests and supports a model showing that user preference for using the new IT depends on user assessment of the usefulness of both the old IT and the new IT. Survey data from a large telecommunications organization that was in the process of adopting a new customer service system while continuing to run the older system in parallel, shows that the respondents?overall preference to use the new IT was, as hypothesized, affected by user perceptions of both IT: perceived usefulness of the new IT increased user preference to adopt the new IT, while perceived usefulness of the old IT decreased it. The perceived usefulness of each system was, as suggested by TAM, increased by the perception of its ease of use. Implications are discussed

Metastatic tumors to the jaws : A report of eight new cases

Purpose: The purpose of the article is to present 8 new cases of metastatic tumors occurring in the jawbones, their clinical features , diagnostic workup and management. Patients and methods: The records of 8 patients with metastatic jaw lesions were reviewd. Demographic data, presenting symptoms, primary tumor site, radiographic findings, bone scintigraphy , histopathology and clinical management were analyzed. Results: The patients , ranged in age from 44 to 80 years, with a mean of 64.5 years. The primary malignant sites were: the lung , the breast , the rectum, the thyroid, the uterus and the parotid gland . The mandible was the site of oral involvement in seven cases and the maxilla in one. There was no gender difference with respect to the oral site affected. The clinical jaw presentations were: exophytic soft tissue mass, paresthesia of the lower lip and a periapical lesion The provided treatment protocols were: chemotherapy , radiotherapy and chemotherapy, surgery and chemotherapy and supportive care only. In one case the jaw lesion was the first indication of an unknown malignancy at a distant primary site. Conclusions: Metastatic jaw lesions are uncommon. Paresthesia of the lower lip and the chin is a sinister sign for patients with a metastatic jaw lesion. In view of these cases it can be said that meticulous work-up of of jaw lesions suspected of being metastatic, may be life saving or extend the patient?s survival period

Lemon sole Microstomus kitt in the northern North Sea: a multidisciplinary approach to the early life-history dynamics

Lemon sole Microstomus kitt is a commercially valuable flatfish species that occurs in shelf waters around the northeast Atlantic. Only the most basic life-history information is available for the North Sea. Spawning is generally assumed to occur between early May and October, with a peak between May and August. Lemon sole larvae have been found in the water column in the northern North Sea in winter during standard surveys. Larvae captured in November/December 2016 and January/February 2017 using the International Council for the Exploration of the Seas standard 2 m Midwater Ring trawls (MIK) were analysed to gain a better understanding of the pelagic early life-history stages of lemon sole, especially in relation to the timing of spawning and the dispersal of overwintering larvae. Larval age was estimated from sagittal otolith primary increment counts. The larvae caught in November/December ranged in nominal age from 4 to 45 days post-hatching which suggests that spawning continues into late October and November. Most, but not all, of the larvae caught in January/February were post metamorphosis, and the difference in age between the two sampling dates was consistent with the elapsed time between samplings. The estimated hatching dates confirm that lemon sole spawning extends into late autumn in the northern North Sea, with overwintering larvae in all developmental stages. Drift modelling of eggs and larvae released at historically documented spawning grounds in the northern North Sea suggests that these grounds are also the source for all of the larvae sampled during the 2016–2017 surveys.publishedVersio

Reviving the Arabian leopard: harnessing historical data to map habitat and pave the way for reintroduction

The Arabian leopard (Panthera pardus nimr) has experienced dramatic range and population contractions over the last century. Conservation efforts for this felid focused on captive breeding and identification of suitable conditions for reintroductions. With this study, we unravelled historical collaring and direct observations data to understand the spatial use of the last leopards recorded in the region of Israel and the West Bank (IWB). Through datasets of leopard occurrence, we characterised suitable habitats, assessed niche overlap with the Arabian leopard's main prey, the Nubian ibex (Capra nubiana), and evaluated their distributions with respect to currently protected habitats. We estimated home-ranges employing area-corrected density kernel methods and investigated suitable conditions through multiple scales habitat modelling. Average home ranges for the population were 73.24 ± 47.91 km2 and 77.46 ± 54.94 km2, depending on the time lag adopted. Ecological response to predictors highlighted reliance by both predator and prey on the same habitat characteristics, suggesting they occupied essentially identical niches. These characteristics were intermediately rugged topographic conditions and high indices of vegetation in scarcely populated desert environments, mostly encompassed within protected areas. The distribution of leopard and ibex overlapped substantially according to several metrics. Notably, more than half of potential habitat for both species is encompassed by protected areas and military zones. Given the coincidence in their ecological requirements, and highly congruent distributions, an important step towards future reintroduction of Arabian leopards will include gaining a better understanding of ibex populations, alongside attention to the practicality of enforcing habitat protection

Listening In on the Past: What Can Otolith δ18O Values Really Tell Us about the Environmental History of Fishes?

Oxygen isotope ratios from fish otoliths are used to discriminate marine stocks and reconstruct past climate, assuming that variations in otolith δ18O values closely reflect differences in temperature history of fish when accounting for salinity induced variability in water δ18O. To investigate this, we exploited the environmental and migratory data gathered from a decade using archival tags to study the behaviour of adult plaice (Pleuronectes platessa L.) in the North Sea. Based on the tag-derived monthly distributions of the fish and corresponding temperature and salinity estimates modelled across three consecutive years, we first predicted annual otolith δ18O values for three geographically discrete offshore sub-stocks, using three alternative plausible scenarios for otolith growth. Comparison of predicted vs. measured annual δ18O values demonstrated >96% correct prediction of sub-stock membership, irrespective of the otolith growth scenario. Pronounced inter-stock differences in δ18O values, notably in summer, provide a robust marker for reconstructing broad-scale plaice distribution in the North Sea. However, although largely congruent, measured and predicted annual δ18O values of did not fully match. Small, but consistent, offsets were also observed between individual high-resolution otolith δ18O values measured during tag recording time and corresponding δ18O predictions using concomitant tag-recorded temperatures and location-specific salinity estimates. The nature of the shifts differed among sub-stocks, suggesting specific vital effects linked to variation in physiological response to temperature. Therefore, although otolith δ18O in free-ranging fish largely reflects environmental temperature and salinity, we counsel prudence when interpreting otolith δ18O data for stock discrimination or temperature reconstruction until the mechanisms underpinning otolith δ18O signature acquisition, and associated variation, are clarified