Regions of Dysfunctional Neural Tissue Associated with Impairment of the Graphemic Buffer in Spelling

The graphemic buffer is a working memory component of the spelling system that temporarily stores the sequence of graphemes while each grapheme is written or spelled aloud. We evaluated 331 patients with left hemisphere stroke on oral and written spelling to dictation, and written picture naming tasks and MRI including within 48 hours of stroke onset. Spelling performance was examined to identify presence or absence of graphemic buffer deficit. A voxel-wise chi-square map revealed that graphemic buffer deficits were associated with ischemia in pre- and post-central gyri, posterior inferior frontal and lateral occipital cortex

A note on the stability and accuracy of finite difference approximations to differential equations

There are many finite difference approximations to ordinary and partial differential equations, and these vary in their accuracy and stability properties. We examine selected commonly used methods and illustrate their stability and accuracy using both linear stability analysis and numerical examples. We find that the formal order of accuracy alone gives an incomplete picture of the accuracy of the method. Specifically, the Adams-Bashforth and Crank-Nicholson methods are shown to have some undesirable features for both ordinary and partial differential equations

Limnological, Ichthyological, and Parasitological Investigations on Arkansas Reservoris in Relation to Water Quality

Lake Fort Smith, a 525 acre (212 ha) reservoir, was impounded in 1936 as a water supply for the city of Fort Smith. The reservoir is located on Clear Creek (Frog Bayou), a tributary of the Arkansas River, in the Boston Mountains 28 miles (45 km) northeast of the city of Fort Smith in Crawford County, Arkansas. A map and morphometric characteristics of Lake Fort Smith are given in Fig. 1 and Table I (Hoffman, 1951; Nelson, 1952). In 1956 Lake Shepherd Springs, a 750 acre (304 ha) impoundment, was created one mile upstream of Lake Fort Smith (Rorie, 1961). Both lakes have a shale substrate and are subject to periods of high turbidity. The 2 two lakes have a water shed of 65 square mile area (168 km ) of mountainous oak-hickory forest. Lake Shepherd Springs has not acted as a settling basin for sediments; thus, the upper portion of Lake Fort Smith has numerous shallow areas with a mud bottom supporting various submergent and emergent aquatic plants. The lower portion of the lake has a rocky, shale substrate with only limited emergent vegetation

Parasites of the Spotted Sucker, Minytrema melanops (Cypriniformes: Catostomidae) from Arkansas and Oklahoma

During October 2015, March and April 2016 and again between March and April 2017, 15 Spotted Sucker (Minytrema melanops) were collected from sites in the Ouachita (n = 5), Red (n = 1), and St. Francis (n = 5) river drainages, Arkansas, and the Arkansas River drainage, Oklahoma (n = 4), and examined for protozoan and metazoan parasites. Found were Calyptospora sp., Myxobolus sp., Pseudomurraytrema alabarrum, Biacetabulum banghami, Penarchigetes oklensis, and Acanthocephalus sp. New host and distributional records are documented for these parasites

The role of the environment in transmission of healthcare associated infection

Infectious diseases are the current leading cause of human death and within this category nosocomial infections remain the most frequent complication of hospitalization. A range of infection prevention and control activities are employed to combat the selection and spread of these organisms. The principle components of which are: early identification of carriage/infection, patient isolation, improved hand hygiene, environmental control and good antimicrobial stewardship. In order to properly focus these interventions, it is essential to know how and when cross transmission has occurred. There is an ongoing debate about the role of the environment in the spread of healthcare associated infections and to what extent if any it acts as a potential vector for transmission. Within the healthcare setting patients spend a substantial amount of time surrounded by equipment and environmental surfaces that may be contaminated with microorganisms. In order to establish what role the environment could play, tracking the spread of organisms by molecular typing is key. The current methods used to do this are complex and often are only available at reference laboratories. This means that turnaround times are slow and only provide retrospective confirmation of cross-transmission events. Infection control interventions that can be used prior to receiving results play an important role. The selection and effectiveness of these interventions are often poorly supported by research studies, leading to problems with the introduction of evidence based practice and thus difficulty in selecting the most appropriate response to suspected cross transmission. This thesis aims to explore the role of the environment in cross transmission of infection by developing sampling methodologies to permit environmental surveillance, validating and developing typing techniques in order to establish epidemiological links between patients and environmental contamination and to evaluate infection control interventions to aid in prevention of cross transmission events