Vocal fatigue among teachers

Recordings were made at the beginning and end of workdays of teachers who experience vocal fatigue (n = 22) and those who do not experience fatigue (n = 17). Those who experienced fatigue were recorded on days in which they did and did not fatigue. Both groups evaluated their vocal characteristics, each time they made a recording. Subsequently, a listener panel evaluated the same characteristics from the recordings. Both groups estimated the amount and characteristics of their talking time, completed a psychological evaluation and provided medical histories. The authors interpret the data obtained as indicating that the vocal characteristics of teachers who fatigue and those who do not fatigue are similar on days the former group does not fatigue and that the two groups are similar in the amount and loudness of their talking time, at work and at home. However, teachers who fatigue tend to spend more time in activities that appear to be vocally demanding and are more likely to perceive situations as being anxiety producing. Teachers who fatigue tend to be in good health, but have had more hearing problems and allergies than their colleagues and more of their family members have had voice problems.     

Menstrual cycle and age: influence on parenchymal contrast medium enhancement in MR imaging of the breast

PURPOSE: To quantify how frequently mesenteric adenitis clinically mimics appendicitis and to determine its appearance at computed tomography (CT). MATERIALS AND METHODS: The medical records of 651 consecutive patients with an admission diagnosis of appendicitis were reviewed to determine how often mesenteric adenitis was the discharge diagnosis. The CT scans of a separate group of 18 patients with a discharge diagnosis of mesenteric adenitis were reviewed. These patients were part of a group of 100 consecutive patients prospectively evaluated with CT of the appendix for clinically suspected appendicitis. RESULTS: Fifty of 651 patients (7.7%) with an admission diagnosis of appendicitis had a discharge diagnosis of mesenteric adenitis. Mesenteric adenitis constituted 50 of the 252 (19.8%) discharge diagnoses other than appendicitis. All 18 CT scans of mesenteric adenitis showed three or more nodes that measured at least 5 mm in shortest axis clustered in the right lower quadrant, with a normal appendix identified. Eight patients had associated ileal or ileocecal wall thickening. CONCLUSION: Mesenteric adenitis is an important clinical mimic of appendicitis. It appears at CT as clustered, enlarged mesenteric lymph nodes with a normal appendix, and there may be associated ileitis or ileocolitis noted.     

Circuitry, architecture, and functional dynamics of visual cortex

A fundamental understanding of the mechanisms of cortical processing requires an examination of the relationships of cortical circuitry, functional architecture, and receptive field properties. Ultimately, this kind of analysis can be utilized to explore the neurobiological basis of psychophysics and perception. At the onset our studies were intended to account for the then known receptive field properties of cortical cells in terms of their underlying circuitry, but surprisingly a good part of the cortical circuit appeared to be in violation of the principles of cortical architecture, and this led us to explore the possibility of new, more complex properties of cortical cells. It has become increasingly possible to relate the responsive specificity of cortical cells, and the circuitry underlying this specificity, to the perceptual capabilities of the visual system by performing analogous experiments on single cells and in human psychophysics.     

Hot carrier effects on analog performance of N- and P-MOSFET's withoxynitride gate dielectrics

In this paper we report the impact of hot-carrier stress on analog performance of n- and p-MOSFET's with conventional oxide, NH₃-nitrided oxide (RTN) and reoxidized nitrided oxide (RTN/RTO) as gate dielectrics. Changes due to hot-carrier stress in crucial analog parameters viz., drain output resistance, voltage gain, and input offset voltage of a source coupled differential MOSFET pair are investigated. Results show that RTN/RTO gate dielectrics suppress degradation of analog parameters in n-MOSFET's but increase it slightly in p-MOSFET's, as compared to conventional oxide MOSFET's     

Impaired motor cortex inhibition in patients with amyotrophic lateral sclerosis. Evidence from paired transcranial magnetic stimulation

We investigated 14 patients with amyotrophic lateral sclerosis (ALS) by paired conditioning-test transcranial magnetic stimulation to test the hypothesis that the motor cortex is hyperexcitable in ALS. Intracortical (corticocortical) inhibition was significantly less in the ALS group than in an age-matched healthy control group (85.3 +/- 27.0% versus 45.2 +/- 15.5%, respectively; p < 0.0001). In contrast, intracortical facilitation, motor threshold, and cortical silent period duration in the ALS patients were not different from the control group. We suggest that the selective abnormality of intracortical inhibition is best compatible with an impaired function of inhibitory interneuronal circuits in the motor cortex that in turn renders the corticomotoneuron hyperexcitable.     

On a responsive replenishment system: a fuzzy logic approach

In today's competitive business environment, it is important that customers are able to obtain their preferred items in the shops they visit, particularly for convenience store chains such as 7–Eleven where popular items are expected to be readily available on the shelves of the stores for buyers. To minimize the cost of running such store chains, it is essential that stocks be kept to a minimum and at the same time large varieties of popular items are available for customers. In this respect, the replenishment system needs to be able to cope with the taxing demands of minimal inventory but at the same time keeping large varieties of needed items. This paper proposes a replenishment system which is able to respond to the fluctuating demands of customers and provide a timely supply of needed items in a cost–effective way. The proposed system embraces the principle of fuzzy logic which is able to deal with uncertainties by virtue of its fuzzy rules reasoning mechanism, thereby leveraging the responsiveness of the entire replenishment system for the chain stores. To validate the feasibility of the approach, a case study has been conducted in an emulated environment with promising results.     

Activity of the plasma membrane H(+)-ATPase and optimal glycolytic flux are required for rapid adaptation and growth of Saccharomyces cerevisiae in the presence of the weak-acid preservative sorbic acid

The weak acid sorbic acid transiently inhibited the growth of Saccharomyces cerevisiae in media at low pH. During a lag period, the length of which depended on the severity of this weak-acid stress, yeast cells appeared to adapt to this stress, eventually recovering and growing normally. This adaptation to weak-acid stress was not due to metabolism and removal of the sorbic acid. A pma1-205 mutant, with about half the normal membrane H+-ATPase activity, was shown to be more sensitive to sorbic acid than its parent. Sorbic acid appeared to stimulate plasma membrane H+-ATPase activity in both PMA1 and pma1-205. Consistent with this, cellular ATP levels showed drastic reductions, the extent of which depended on the severity of weak-acid stress. The weak acid did not appear to affect the synthesis of ATP because CO2 production and O2 consumption were not affected significantly in PMA1 and pma1-205 cells. However, a glycolytic mutant, with about one-third the normal pyruvate kinase and phosphofructokinase activity and hence a reduced capacity to generate ATP, was more sensitive to sorbic acid than its isogenic parent. These data are consistent with the idea that adaptation by yeast cells to sorbic acid is dependent on (i) the restoration of internal pH via the export of protons by the membrane H+-ATPase in an energy-demanding process and (ii) the generation of sufficient ATP to drive this process and still allow growth.