Comparative usability of modern anaesthesia ventilators: a human factors study.

BACKGROUND: The anaesthesia ventilator represents the key equipment for intraoperative respiratory care. Improper operation of this device may threaten a patient's health. A self-explanatory interface facilitates handling and decreases the risk of operating errors. This study systematically evaluates the usability of user interfaces in four modern anaesthesia ventilators. METHODS: Twenty naïve operators were asked to execute 20 tasks on each of four different anaesthesia ventilators (Avance CS2™, GE Healthcare; Flow-i™, Maquet; and Perseus™ and Primus™, Dräger) in a randomized order. The success of task execution, frequency of requests for assistance, and processing times were recorded. During the tasks, the operators' visual focus was measured via eye-tracking. Additionally, subjective assessments of usability were evaluated by a standardized questionnaire. For comparison, six experienced operators undertook the same protocol. RESULTS: The overall rate of falsely executed tasks was low. Naïve operators requested assistance least when using the Perseus (26). Pooled processing times were shortest for the Perseus (222 s), followed by the Primus (223 s), the Avance (238 s), and the Flow-i (353 s). Task-specific processing times differed considerably between the devices. Eye-tracking analyses revealed associated interface issues that impeded the operators' performance. Operators rated usability best for the Perseus [mean (sd): 67 (17) arbitrary units] and worst for the Flow-i [50 (16) arbitrary units]. Results from experienced operators support these findings by trend. CONCLUSIONS: The usability of modern anaesthesia ventilators differs considerably. Interface issues of specific tasks impair the operator's efficiency. Eliminating the specific usability issues might improve the operator's performance and, as a consequence, the patient's safety.

FLOW CYTOMETRIC DETECTION OF SUBHAPLOID NUCLEI IN HUMAN SPERM AS A MEASURE OF DNA FRAGMENTATION AND APOPTOSIS.

The use of assisted reproductive technologies (ARTs) is increasing worldwide. In order to predict the rate of pregnancy after ART the DNA fragmentation index (DFI) of ejaculated spermatocytes may be a better marker than conventional semen quality parameters. Spermatocytes with fragmented DNA are associated with apoptotic stages and are characterized by a low DNA content. The subhaploid nuclei of DNA-damaged spermatocytes can be easily detected by flow cytometry. We here analyzed the percentage of subhaploid nuclei of semen samples from 163 patients aged 26 to 74 years who consulted one of the ten centres for reproductive medicine which routinely send sperm samples to our laboratory in order to determine special sperm parameters. The percentage of subhaploid nuclei indicating the DFI of spermatocytes did not correlate with age and sperm volume, but inversely correlated with sperm concentration and the percentage of motile spermatocytes. This is in concordance with previous studies which demonstrated that DNA damage of spermatozoa correlates with conventional semen quality parameters. Since DNA-damaged spermatocytes are associated with an impaired outcome of assisted conception technologies, this method could help to monitor sperm quality of subfertile men after measures to increase sperm quality and to improve selection criteria of cryopreserved sperm samples in assisted reproduction medicine.

[Is bovine leishmaniasis spreading in Switzerland?]. / Breitet sich die bovine kutane Leishmaniose in der Schweiz aus?

The purpose of the present study was based upon the first diagnosed bovine cutaneous leishmaniasis in a cow in Switzerland in April 2009. We continued descriptively the search for other bovine cases in Switzerland. We carried out similar investigations in the original farm where the case had occurred, and in parallel also in the neighboring farm. Additionally, veterinary practitioners sent us an overall of 12 suspected cases of bovine leishmaniasis. Following diagnostic investigations, all cases were negative for Leishmania. The occurrence of this infection appears therefore to be a very rare event. Finally some differential diagnoses are discussed.

Long-term changes in the small-world organization of brain networks after concussion.

There is a growing body of literature using functional MRI to study the acute and long-term effects of concussion on functional brain networks. To date, studies have largely focused on changes in pairwise connectivity strength between brain regions. Less is known about how concussion affects whole-brain network topology, particularly the "small-world" organization which facilitates efficient communication at both local and global scales. The present study addressed this knowledge gap by measuring local and global efficiency of 26 concussed athletes at acute injury, return to play (RTP) and one year post-RTP, along with a cohort of 167 athletic controls. On average, concussed athletes showed no alterations in local efficiency but had elevated global efficiency at acute injury, which had resolved by RTP. Athletes with atypically long recovery, however, had reduced global efficiency at 1 year post-RTP, suggesting long-term functional abnormalities for this subgroup. Analyses of nodal efficiency further indicated that global network changes were driven by high-efficiency visual and sensorimotor regions and low-efficiency frontal and subcortical regions. This study provides evidence that concussion causes subtle acute and long-term changes in the small-world organization of the brain, with effects that are related to the clinical profile of recovery.

Cognitive and Affective Aspects of Creative Option Generation in Everyday Life Situations.

Which factors influence a human being's ability to develop new perspectives and be creative? This ability is pivotal for any context in which new cognitions are required, such as innovative endeavors in science and art, or psychotherapeutic settings. In this article, we seek to bring together two research programs investigating the generation of creative options: On the one hand, research on option generation in the decision-making literature and, on the other hand, cognitive and clinical creativity research. Previous decision-making research has largely neglected the topic of generating creative options. Experiments typically provided participants with a clear set of options to choose from, but everyday life situations are less structured and allow countless ways to react. Before choosing an option, agents have to self-generate a set of options to choose from. Such option generation processes have only recently moved to the center of attention. The present study examines the creative quality of self-generated options in daily life situations. A student sample (N = 48) generated options for action in 70 briefly described everyday life scenarios. We rated the quality of the options on three dimensions of creativity- originality, feasibility, and divergence -and linked these qualities to option generation fluency (speed and number of generated options), situational features like the familiarity and the affective valence of the situation in which the options were generated, and trait measures of cognitive performance. We found that when situations were familiar to the participant, greater negative affective valence of the situation was associated with more originality and divergence of generated options. We also found that a higher option generation fluency was associated with a greater maximal originality of options. We complete our article with a joint research agenda for researchers in the decision-making field focusing on option generation and, on the other hand, researchers working on the cognitive and clinical aspects of creativity.

Gastric emptying and glycemic response after ingestion of mashed bean or potato flakes in composite meals.

Two meals of mashed-bean or potato flakes and meat were served in random order to six healthy male subjects to determine effects on gastric emptying and glycemic reactions. The meals had comparable physical appearance and contained similar amounts of digestible carbohydrate, fat, and protein. No difference in gastric emptying, recorded by gamma camera after mixing 51Cr with the meals, was found between the meals. The bean-flakes meal gave significantly lower blood glucose (p less than 0.01) and serum insulin (p less than 0.05) concentrations than did the potato-flakes meal. The overall blood glucose response, calculated as incremental area under the curves for 2 h, also differed between the meals (p less than 0.05) whereas the overall insulin response did not differ significantly. The low glycemic response after bean flakes could not be explained by the gastric emptying rate, which provides additional evidence for the slow digestion of bean starch in the small intestine.

Metabolic effects of dietary fiber from dehulled soybeans in humans.

The normal diet of six healthy volunteers was supplemented by 21 g of dietary fiber from two different soybean seed fiber preparations, either a nonpurified and never-dried soya pulp A (39% dietary fiber) or a purified soya fiber B (79%), for 3 wk each. Mean daily fecal wet weight was increased by 19 and 38% in the fiber periods A and B as compared to a 2-wk control period (p less than 0.05). Stool frequency and transit time remained unchanged. Fecal fiber increased by 52% only during period B. Fecal calcium, magnesium, and iron were increased (p less than 0.05), mainly after higher intakes during both fiber periods. Excretion of neutral steroids remained unchanged, but their concentration was lowered (p less than 0.05). A 21% increase of fecal bile acids by fiber A was specifically due to deoxycholic acid (+32%, p less than 0.01). Oral glucose tolerance was slightly improved after period B. Neither fiber changed serum triglycerides, but fiber B increased low-density lipoprotein-cholesterol by 19% (p less than 0.01) and low-density lipoprotein-phospholipids by 16% (p less than 0.05). The ratio high-density/low-density lipoprotein-cholesterol, however, did not change significantly. Thus, dietary fibers from soybean do not seem to contribute to the hypocholesterolemic effect of soya. The results of this study also demonstrate that two apparently similar dietary fibers, coming from a single source, can exert distinctly different metabolic effects.

Fabrication and spectroscopy of erbium doped gallium lanthanum sulphide glass fibres for mid-infrared laser applications.

Gallium lanthanum sulphide based glasses are proposed as high quality hosts for rare-earth doped, mid-infrared fibre lasers, that would offer compact and rugged sources for gas sensing, atmospheric transmission, and medical applications. The infrared emission spectroscopy of erbium doped glasses and fibres shows the potential of this glass host for the above applications. Mid-infrared transitions at 2.0, 2.75, 3.6, and 4.5mm have been detected and characterized.

Hydrogen excretion after ingestion of five different sugar alcohols and lactulose.

The breath hydrogen excretion was measured for 5 h after the initial rise on seven subjects who consumed randomly, and after 5 d of adaptation, equimolar amounts of sorbitol (10 g), mannitol (10 g), maltitol (19 g), Palatinit (19 g anhydrous), lactitol (19 g anhydrous), lactulose (19 g) in aqueous solution. The mean mouth-to-caecum transit time was 1.5 h, which was not significantly different from one carbohydrate to another, but varied significantly from one subject to another (0.7-2.4 h). Suprabasal increment of breath hydrogen after lactitol was significantly higher than that from the other polyols (P less than 0.001) over 5 h. Lactitol and lactulose, which are known to be totally undigested in the small intestine, gave the highest mean incremental area under the breath hydrogen curve, 327 p.p.m. H2 over 5 h and 224 p.p.m. H2 over 5 h, respectively. The values for the other test compounds ranged from 145 to 209 p.p.m. H2 over 5 h, which suggest that there had been only partial absorption in the small intestine.

Digestion and absorption of sorbitol, maltitol and isomalt from the small bowel. A study in ileostomy subjects.

OBJECTIVE: To quantify small bowel digestion and absorption of sorbitol, isomalt and maltitol in ileostomy patients and estimate the metabolizable energy. SUBJECTS: Study A: Nine ileostomy patients, under a constant controlled diet, ate during three consecutive days 2 milk chocolate bars per day, containing 2 x 15 g of polyol, each day with another polyol in random order. The first bar was taken 30 min after breakfast, and the second bar, 7 h after breakfast. Effluents were recovered during the whole study. Study B: 5, 10 or 20 g of sorbitol or isomalt were consumed each day in a drink during two 3-day periods by two ileostomy subjects. The recovery in the ileal effluent was measured over 24 h. RESULTS: Study A: Carbohydrate recovery in ileostomy effluent was 26.8 +/- 2.8% (mean+SEM) for sorbitol, 24.8 + 5.7% for maltitol (2/3 as sorbitol) and 40.0 +/- 0.7% for isomalt (1/3 being sorbitol and mannitol). Ileal excretion, compared with a day without polyol, was compared in 4 subjects. The total volume excreted, as well as dry matter increased after polyol consumption. When taking this extra loss into account, the metabolizable energy value of the polyols for 2 x 15 g intake were: sorbitol, 12 kJ/g (2.8 kcal/g); maltitol, 13 kJ/g (3.1 kcal/g); isomalt, 9 kJ/g (2.1 kcal/g). Study B: The level of digestion and absorption of both sugar alcohols was dose dependent. CONCLUSIONS: These results indicate that sorbitol, maltitol and isomalt are rather extensively absorbed, but the digestibility of the other nutrients is also reduced, due to the osmotic load caused by the polyols in the small intestine. There are evidences of a dose dependency of the energy value of the polyols.

Nutrients excreted in ileostomy effluents after consumption of mixed diets with beans or potatoes. I. Minerals, protein, fat and energy.

The small intestinal excretion of protein, fat, energy, magnesium, calcium, iron and zinc from two isocaloric diets including either instant bean flakes (174 g/d) or potato flakes (102 g/d) was studied in seven ileostomy subjects. Out of the variable part of the diet all starch and dietary fibre, and about half of the energy was provided from bean flakes or potato flakes, respectively. The small variation in ileostomy excretion between two consecutive days, after one adaptation day, suggests that ileostomy studies can be performed with reasonable precision in 2 days. During the 2-day potato period average daily excretions of gross energy and protein were 236 kcal (988 kJ; 11 per cent of intake) and 13 g (12 per cent), respectively. The excretions were significantly (P less than 0.001) higher during the bean period, 378 kcal (1582 kJ; 16 per cent) and 17 g (15 per cent). Fat intake and excretion were not different. After making allowance for dietary fibre, the apparent nutrient energy digestibilities were over 90 per cent, with only 43 kcal (180 kJ; 2 per cent) difference between the two periods. Apparent absorption of magnesium was lower during the bean period, 7 per cent compared to 25 per cent (P less than 0.02). The study has thus shown that only slightly less apparent small intestinal absorption occurs from a diet with bean flakes compared to potato flakes, so the nutritional consequences of beans on other nutrients seem to be small.

Nutrients excreted in ileostomy effluents after consumption of mixed diets with beans or potatoes. II. Starch, dietary fibre and sugars.

The extent of carbohydrate digestion and absorption from two diets including either instant bean flakes (174 g/d) or potato flakes (102 g/d) was measured in seven ileostomy subjects during a 2-day period. Test foods contributed 40 per cent of the total dietary starch intake (160 g/d), the remainder coming from rice and white bread. Overall, 4 per cent and 0.7 per cent of the dietary starch consumed remained unabsorbed during the bean and potato periods, respectively. Between 9.0 and 10.9 per cent of dietary bean starch and less than 1.7 per cent of potato starch were not absorbed. Dietary fibre and resistant starch were completely recovered in ileostomy effluents. In separate meal tests with 40 g starch, beans gave lower blood glucose (P less than 0.05) and serum insulin (P less than 0.01) responses than potatoes. Dietary starch malabsorption from leguminous foods is less than previously estimated and does not explain the attenuated glycaemic and insulinaemic responses.

Structural features of resistant starch at the end of the human small intestine.

Structural features of in vivo resistant starch were assessed using the ileal contents of four humans. Two of the latter were collected by ileostomy after ingestion of bean flakes or potato flakes and the other two were collected by an intubation technique after ingestion of retrograded high-amylose maize starch or complexed high-amylose maize starch. The degree of polymerizations (DP), solubility and crystallinity were assessed. For all samples, starch fractions which escaped digestion in the small intestine were composed of three populations of alpha-glucans with proportions differing according to the substrate. Small quantities of oligosaccharides made up the first population, illustrating a limitation of absorption in the small intestine. The second population, the main resistant fraction, was comprised of retrograded amylose of mean DPn of about 35 glucose units with a melting temperature at 150 degrees C and exhibiting a B-type pattern. Finally high molecular weight semi-crystalline alpha-glucans were attributed to fragments of starch. This study showed that some potentially digestible starch could reach the colon and crystalline fractions constituted only part of the starch that escaped digestion in the human small intestine.

Presynaptic regulation of neurotransmitter release in the cortex of aged rats with differential memory impairments.

Cluster analysis of water-maze reference-memory performances of 25-27-month-old (compared to 3-5-month-old) rats distinguished subpopulations of young adult rats (YOUNG), aged rats with no significant impairment (AU), aged rats with moderate impairment (AMI), and aged rats with severe impairment (ASI). In the frontoparietal cortex, we subsequently assessed the electrically evoked release of tritium in slices preloaded with [3H]choline, [3H]noradrenaline (NA), or [3H]serotonin (5-HT) and the effects of an agonist (oxotremorine, UK 14,304, and CP 93,129) of the respective autoreceptors. Cholinergic and monoaminergic markers were measured in homogenates. Overall, aged rats exhibited reduced accumulation of [3H]choline (-25%) and weaker evoked transmitter release (in % of accumulated tritium: -44%, -20%, and -34%, for [3H]acetylcholine, [3H]NA, and [3H]5-HT, respectively). In all rats, the inhibitory effects of the autoreceptor agonists on the evoked release of [3H] were comparable. Acetylcholinesterase (AChE), not choline acetyltransferase (ChAT), activity was reduced. The results suggest age-related modifications in the cholinergic, noradrenergic, and serotonergic innervation of the frontoparietal cortex, alterations of evoked transmitter release, but no interference with presynaptic autoinhibition of the release. Neither of these alterations seemed to account for the cognitive impairment assessed.

Alcohol affects processing of ignored stimuli in a negative priming paradigm.

OBJECTIVE: This research examined the effect of alcohol on negative priming, which is considered to reflect a basic process of selective attention. METHOD: Male social drinkers (N = 28) performed a color naming reaction time (RT) task that measured negative priming. After a baseline test on the task, they received either 0.56 g/kg of alcohol or a placebo; they then performed the task twice. RESULTS: In accord with the hypotheses, alcohol suppressed negative priming during the ascending limb but not during the descending limb of the blood alcohol curve. No suppression of negative priming was evident under placebo. CONCLUSIONS: The suppression of this process by alcohol may represent a basic mechanism by which the drug reduces the ability to efficiently allocate attention and leads to impaired performance on various attention-based tasks (e.g., divided attention and vigilance tasks).

Differential effects of alcohol on responses to negatively and positively primed stimuli.

OBJECTIVE: As shown in previous research, alcohol suppresses negative priming, an effect that normally occurs when subjects are required to respond to information that had been previously ignored. The present research examined the generality of this effect by testing the effect of alcohol on responses to positively primed stimuli that did not require responding to previously ignored information. METHOD: Twenty-eight male social drinkers performed a color-naming reaction time task that measured both negative and positive priming effects. After a baseline test on the task, they received either 0.56 g/kg of alcohol or a placebo, and then performed the task twice. RESULTS: The results showed a differential effect of alcohol on negative and positive priming. Alcohol suppressed negative priming, but had no effect on the magnitude of positive priming. CONCLUSIONS: Evidence for a selective effect of alcohol on negative, but not positive, priming suggests that the drug does not reduce negative priming by impairing memory of priming stimulus information. Rather, the findings provide further support for a specific impairment of an inhibitory process that normally serves to prevent interference from distracting, to be ignored, stimuli. Impairment of this process by alcohol could represent a basic cognitive mechanism by which the drug disrupts performance of laboratory tasks that require visual attention, such as divided attention and vigilance tasks.

Determination of soluble dietary fiber in foods and food products: collaborative study.

A collaborative study was conducted to determine the soluble dietary fiber (SDF) content of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that employed for determining total dietary fiber (TDF), 985.29, and the method for insoluble dietary fiber (IDF), 991.42. Ten laboratories were each sent 13 test samples (6 blind duplicates and 1 standard [green beans] containing 29-33% TDF, 19-23% IDF, and 8-13% SDF) and were instructed to assay for IDF, SDF, and TDF independently. Included in the package were the 3 enzymes, namely alpha-amylase, amyloglucosidase, and protease, and the filter aid Celite, which was thought to be the major cause of high reproducibility relative standard deviation (RSDR) values for SDS obtained in a previous collaborative study. The foods to be analyzed were apricots, carrots, chickpeas, onions, raisins, and the sugar beet fiber Fibrex. IDF, TDF, and SDF were calculated as the weight of residue minus the weight of protein and ash on a dry weight basis. RSDR values of the IDF results averaged 8.02%, with only 1 food having an RSDR > 10%. The RSDR values for the TDF results averaged 4.97%, and all foods had an RSDR < 7%. Although the RSDR values for SDF averaged 14.17%, 4 of the 6 foods had an RSDR < 10%, and 1 of the 2 remaining foods that had a high RSDR had an SDF content of only 1.2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography of the normal bovine heart: technique and ultrasonographic appearance.

Fifty-one clinically healthy cows were examined ultrasonographically from the third and fourth intercostal spaces on both sides of the thorax. A 3.0 MHz transducer was used and the heart was examined in the caudal long, caudal short and cranial long axes on the right side, and in the caudal and cranial long axes on the left side. In each position the optimal transducer orientation and the images of the structures were recorded. In the caudal long axis view of the heart on the right (transducer positioned at the fourth intercostal space), all four chambers were visible with the transducer positioned 8 to 10 cm dorsal to the level of the olecranon. The left ventricular outflow tract, consisting of the aortic valve and ascending aorta, were visible in the same position with the transducer rotated 10 to 40 degrees clockwise. In the caudal short axis view of the heart on the right, the left and right ventricles were visible in cross-section with the transducer held at right angles to the ribs in the fourth intercostal space, 3 to 6 cm dorsal to the olecranon and tipped slightly dorsally. In the cranial long axis view of the heart on the right, the right ventricular outflow tract, consisting of the pulmonary valve and pulmonary artery, was visible in the third intercostal space, 8 to 10 cm dorsal to the olecranon with the transducer angled craniodorsally and rotated 10 to 20 degrees clockwise. In the caudal long axis view of the heart on the left, the left and right ventricles and the left ventricular outflow tract were visible with the transducer placed in the fourth intercostal space. In the cranial long axis view on the left, the right ventricular outflow tract was visible.

Decreased sedation by xylazine and high blood pressure in cows with BSE.

Fifteen cows with bovine spongiform encephalopathy (BSE) and 90 healthy cows were given xylazine intramuscularly at a dosage of 0.15 mg/kg bodyweight. The onset of sedation and of drooling was recorded, and the heart and respiratory rates and the systolic and diastolic blood pressure were measured every five minutes for 40 minutes. All the healthy cows but only five of the 15 cows with BSE became sedated, and the period between the administration of xylazine and the onset of sedation was twice as long in the cows with BSE than in the healthy cows (15.0 [7.5] and 7.6 [2.6] minutes). Throughout the observation period, the blood pressure of the cows with BSE was significantly higher than that of the healthy cows, and the blood pressure of the healthy cows, but not of the cows with BSE, decreased significantly towards the end of the observation period.

[182 offspring of cows with bovine spongiform encephalopathy (BSE) in Switzerland. 1. Clinical findings]. / Untersuchungen an 182 Nachkommen von an boviner spongiformer Enzephalopathie (BSE) erkrankten Kühen in der Schweiz. Teil 1: Klinische Befunde.

This study involved 182 calves, heifers and cows that were the first generation progeny of cows with bovine spongiform encephalopathy (BSE). All animals underwent clinical and neurological examinations. Blood, milk, urine, ruminal fluid and cerebrospinal fluid samples were examined. Each cow underwent a specific examination for BSE which included assessment of behaviour, sensitivity and locomotion. This examination was performed twice, and there was very good agreement between the results. The most common symptom was nervousness (14 animals). In the first examination, 68 animals were mildly to moderately sensitive to touching of the head, 44 animals were hypersensitive to a halogen light and 35 animals were hypersensitive to a camera flash. Twenty-four animals reacted by kicking when the hindlimbs were touched with a broom. None of the animals had disturbances in locomotion. Based on the interpretation of all findings and the comparison of the results of the first and second examinations, 173 animals were diagnosed as free of BSE. In 9 animals, the disease could not be ruled out; however, it could not be confirmed in any of them. Histological and immunohistochemical examinations of the brain of all animals were negative for BSE (see Part 2 of the study for details). The results of this study indicate that abnormal clinical findings may occur in clinically healthy cattle. However, none of the progeny of cows with BSE exhibited clinical signs typical of BSE, such as disturbances in behaviour; sensitivity and locomotion.