Eye-tracking the time-course of novel word learning and lexical competition in adults and children.

Lexical competition is a hallmark of proficient, automatic word recognition. Previous research suggests that there is a delay before a new spoken word becomes engaged in this process, with sleep playing an important role. However, data from one method - the visual world paradigm - consistently show competition without a delay. We trained 42 adults and 40 children (aged 7-8) on novel word-object pairings, and employed this paradigm to measure the time-course of lexical competition. Fixations to novel objects upon hearing existing words (e.g., looks to the novel object biscal upon hearing "click on the biscuit") were compared to fixations on untrained objects. Novel word-object pairings learned immediately before testing and those learned the previous day exhibited significant competition effects, with stronger competition for the previous day pairings for children but not adults. Crucially, this competition effect was significantly smaller for novel than existing competitors (e.g., looks to candy upon hearing "click on the candle"), suggesting that novel items may not compete for recognition like fully-fledged lexical items, even after 24h. Explicit memory (cued recall) was superior for words learned the day before testing, particularly for children; this effect (but not the lexical competition effects) correlated with sleep-spindle density. Together, the results suggest that different aspects of new word learning follow different time courses: visual world competition effects can emerge swiftly, but are qualitatively different from those observed with established words, and are less reliant upon sleep. Furthermore, the findings fit with the view that word learning earlier in development is boosted by sleep to a greater degree.

Na+-K+-ATPase properties in rat heart and skeletal muscle 3 mo after coronary artery ligation.

This study was designed to determine whether chronic heart failure (CHF) results in changes in Na(+)-K(+)-ATPase properties in heart and skeletal muscles of different fiber-type composition. Adult rats were randomly assigned to a control (Con; n = 8) or CHF (n = 8) group. CHF was induced by ligation of the left main coronary artery. Examination of Na(+)-K(+)-ATPase activity (means +/- SE) 12 wk after the ligation measured, using the 3-O-methylfluorescein phosphatase assay (3-O-MFPase), indicated higher (P < 0.05) levels in soleus (Sol) (250 +/- 13 vs. 179 +/- 18 nmol.mg protein(-1).h(-1)) and lower (P < 0.05) levels in diaphragm (Dia) (200 +/- 12 vs. 272 +/- 27 nmol.mg protein(-1).h(-1)) and left ventricle (LV) (760 +/- 62 vs. 992 +/- 16 nmol.mg protein(-1).h(-1)) in CHF compared with Con, respectively. Na(+)-K(+)-ATPase protein content, measured by the [(3)H]ouabain binding technique, was higher (P < 0.05) in white gastrocnemius (WG) (166 +/- 12 vs. 135 +/- 7.6 pmol/g wet wt) and lower (P < 0.05) in Sol (193 +/- 20 vs. 260 +/- 8.6 pmol/g wet wt) and LV (159 +/- 10 vs. 221 +/- 10 pmol/g wet wt) in CHF compared with Con, respectively. Isoform content in CHF, measured by Western blot techniques, showed both increases (WG; P < 0.05) and decreases (Sol; P < 0.05) in alpha(1). For alpha(2), only increases [red gastrocnemius (RG), Sol, and Dia; P < 0.05] occurred. The beta(2)-isoform was decreased (LV, Sol, RG, and WG; P < 0.05) in CHF, whereas the beta(1) was both increased (WG and Dia; P < 0.05) and decreased (Sol and LV; P < 0.05). For beta(3), decreases (P < 0.05) in RG were observed in CHF, whereas no differences were found in Sol and WG between CHF and Con. It is concluded that CHF results in alterations in Na(+)-K(+)-ATPase that are muscle specific and property specific. Although decreases in Na(+)-K(+)-ATPase content would appear to explain the lower 3-O-MFPase in the LV, such does not appear to be the case in skeletal muscles where a dissociation between these properties was observed.

Malleability of human skeletal muscle Na(+)-K(+)-ATPase pump with short-term training.

To investigate the hypothesis that short-term submaximal training would result in changes in Na(+)-K(+)-ATPase content, activity, and isoform distribution in skeletal muscle, seven healthy, untrained men [peak aerobic power (peak oxygen consumption; Vo(2 peak)) = 45.6 ml x kg(-1) x min(-1) (SE 5.4)] cycled for 2 h/day at 60-65% Vo(2 peak) for 6 days. Muscle tissue, sampled from the vastus lateralis before training (0 days) and after 3 and 6 days of training and analyzed for Na(+)-K(+)-ATPase content, as assessed by the vanadate facilitated [(3)H]ouabain-binding technique, was increased (P < 0.05) at 3 days (294 +/- 8.6 pmol/g wet wt) and 6 days (308 +/- 15 pmol/g wet wt) of training compared with 0 days (272 +/- 9.7 pmol/g wet wt). Maximal Na(+)-K(+)-ATPase activity as evaluated by the 3-O-methylfluorescein phosphatase assay was increased (P < 0.05) by 6 days (53.4 +/- 5.9 nmol x h(-1) x mg protein(-1)) but not by 3 days (35.9 +/- 4.5 nmol x h(-1) x mg protein(-1)) compared with 0 days (37.8 +/- 3.7 nmol x h(-1) x mg protein(-1)) of training. Relative isoform distribution, measured by Western blot techniques, indicated increases (P < 0.05) in alpha(2)-content by 3 days and beta(1)-content by 6 days of training. These results indicate that prolonged aerobic exercise represents a potent stimulus for the rapid adaptation of Na(+)-K(+)-ATPase content, isoform, and activity characteristics.

Taking perspective in conversation: the role of mutual knowledge in comprehension.

When people interpret language, they can reduce the ambiguity of linguistic expressions by using information about perspective: the speaker's, their own, or a shared perspective. In order to investigate the mental processes that underlie such perspective taking, we tracked people's eye movements while they were following instructions to manipulate objects. The eye fixation data in two experiments demonstrate that people do not restrict the search for referents to mutually known objects. Eye movements indicated that addressees considered objects as potential referents even when the speaker could not see those objects, requiring addressees to use mutual knowledge to correct their interpretation. Thus, people occasionally use an egocentric heuristic when they comprehend. We argue that this egocentric heuristic is successful in reducing ambiguity, though it could lead to a systematic error.

Patients who refuse transportation by ambulance: a case series.

INTRODUCTION: Patients refusing hospital transportation occurs in 5% to 25% of out-of-hospital calls. Little is known about these calls. This study was needed to determine the demographics, inherent risks, and timing of refused calls. METHODS: This was a prospective review of all run sheets of patients who refused transportation were collected for a two month period. Demographic data and medical information was collected. Each run was placed into one of three categories of need for transport and further evaluation: 1) minimal; 2) moderate; and 3) definite. The Greater Elgin Area Mobile Intensive Care Program (GEA-MICP) based at Sherman Hospital in Elgin, Illinois, was the setting. The GEA-MICP is an Emergency Medical Services (EMS) system comprised of 17 advanced life support (ALS) ambulance agencies servicing northeastern Illinois. Study subjects were all patients who refused transportation to a hospital by ALS ambulance during July 1993 and February 1994. Paramedics were required to complete a run sheet for all calls. RESULTS: Overall, 30% (683 of 2,270) of all runs resulted in refusal of transportation. Patients who most commonly refused transportation were asymptomatic, 11-40 years old and involved in a motor vehicle crash. They usually had no past medical history, normal vital signs, and a normal mental status. Patients generally signed for their own release after evaluation. The average time to arrival was 4.2 minutes and average time spent on scene by paramedics was 18.4 minutes. Of the patients, 72% were judged to have minimal need, 25% were felt to have a moderate need, and 3% were felt to definitely need transport to a hospital for further evaluation and/or treatment. CONCLUSION: There are many cases when EMS are activated, but transportation is refused. Most refusals occur after paramedic evaluation. Providing paramedics with primary care training and protocols would standardize care given to patients and provide a mechanism for discharge instructions and follow-up for those who chose not to be transported to a hospital. Patients judged to require further treatment had unique characteristics. These data may be useful in identifying potentially sicker patients allowing a concentrated effort to transport this subset of patients to a hospital.

Isolation and characterization of cellulolytic anaerobic fungi and associated mycoplasmas from the rumen of a steer fed a roughage diet.

The isolation of 12 strains of cellulolytic fungi from the rumen of a roughage-fed steer is described. These represented three different genera, including one new genus and species (Orpinomyces bovis). The organisms were indistinguishable on the basis of fermentation products from cellulose, and their fermentation patterns were very similar to those of rumen fungi isolated in other countries. Mycoplasmas were found to be associated with 7 of the 12 isolates. The ecological role of the association of the mycoplasmas with rumen fungi is still unknown.

How modern systematics relates to the rumen fungi.

The zoosporic fungi comprise a polyphyletic grouping of four classes, the Plasmodiophoromycetes, Oomycetes, Hyphochytriomycetes and Chytridiomycetes. Apart from their absorptive mode of nutrition and the presence of zoospores in some stage of their life cycle, there is little these classes have in common. The zoosporic species of rumen fungi are classified in the Class Chytridiomycetes which is a monophyletic group with extreme diversity in thallus morphology, reproduction and zoospore cytology. The rumen fungi have many characteristics in common with the Spizellomycetaceae but have been given their own family, the Neocallimasticaceae. There are arguments for reducing this family to synonymy with the Spizellomycetaceae, or elevating it to a new order, but before a rational decision can be made, more rumen fungi require detailed examination, especially their zoospore ultrastructure.

Bypass phrynoderma. Vitamin A deficiency associated with bowel-bypass surgery.

A 41-year-old woman had multiple keratotic papules and nodules on the trunk and extremities four years after a bowel-bypass procedure for morbid obesity. The microscopic features were those of a perforating folliculitis. Serum vitamin A levels were extremely low. Oral vitamin A therapy resulted in dramatic improvement of the cutaneous lesions.

The phylogenetic and taxonomic implications of flagellar rootlet morphology among zoosporic fungi.

Rootlet morphology shows that the Oomycetes excluding the Thraustochytriales, the Thraustochytriales independently, and the Hyphochytriomycetes probably evolved as three distinctive lines from chrysophycean ancestors. The Plasmodiophoromycetes rootlet system does not show any similarity to rootlet systems in other zoosporic fungi, and this class may have arisen from the Protozoa. The varied rootlet systems present in the Chytridiomycetes show that this class has a very primitive origin and long evolutionary history. The composition of the rootlet systems in different Chytridiomycete taxa indicate that the Monoblepharidiales evolved from the Chytridiales, and the Blastocladiales from the Spizellomycetales.

Taxonomy and phylogeny of chytrids.

Thallus development, zoospore size, zoospore ultrastructural complexity and organization, and flagellum length are cited as important in phylogeny of the Chytridiales (chytrids) and should be the bases for this classification. Discharge of zoospores is also cited as important although emphasis is not placed on operculation. It is proposed that simple, eucarpic, monocentric chytrids which discharge zoospores following dissolution of the sporangium wall evolved into multipapilliate species of Rhizophydium and 2 lines of evolution from these species are documented with examples. In one line they evolved into single-pored species such as R. pollinis-pini, then to Chytridium and tendochytrium-like chytrids and to polycentric chytrids such as Nowakowskiella and Cladochytrium. The second line evolved from multipapilliate Rhizophydium species to Phlyctochytrium and Entophlyctis, and to the order Blastocladiales. Rhizophlyctis rosea and some olpidiaceous chytrids, because of a fibrillar rhizoplast in their zoospores do not appear close to Rhizophydium-related chytrids and may require separate subordinal rank in classification. It is proposed that zoospores of the advanced members of the class Chytridiomycetes have reached limits for further zoospore development because of size; however, the zoospore is no longer essential for them because they have developed a filamentous habit of growth.