238 research outputs found
Steering in layers above the display surface
Interaction techniques that use the layers above the display surface to extend the functionality
of pen-based digitized surfaces continue to emerge. In such techniques, stylus movements are
constrained by the bounds of a layer inside which the interaction is active, as well as constraints
on the direction of movement within the layer. The problem addressed in this thesis is that
designers currently have no model to predict movement time (MT) or quantify the difficulty, for
movement (steering) in layers above the display surface constrained by thickness of the layer, its
height above the display, and the width and length of the path. The problem has two main parts:
first, how to model steering in layers, and second, how to visualize the layers to provide
feedback for the steering task. The solution described is a model that predicts movement time
and that quantifies the difficulty of steering through constrained and unconstrained paths in
layers above the display surface. Through a series of experiments we validated the derivation and applicability of the proposed models. A predictive model is necessary because the model serves as the basis for design of interaction techniques in the design space; and predictive models can be used for quantitative evaluation of interaction techniques. The predictive models are important as they allow researchers to evaluate potential solutions independent of experimental conditions.Addressing the second part of the problem, we describe four visualization designs using cursors. We evaluated the effectiveness of the visualization by conducting a controlled experiment
Population ecology of freshwater mussel Parreysia corrugata (Mullar 1774) from River Malthi, Tributary of river Tunga in the Western Ghats, India
The The freshwater mussel Parreysia corrugata (Muller, 1774) is common in rivers of India. The growth, mortality and recruitment of P. corrugata were studied from March 2007 to June 2008 from river Malthi, tributary of river Tunga, in the Western Ghats. A total of 1587 individuals ranging from 17 to 57 mm size were subjected to analysis. The recruitment pattern produced one cohort per year and the highest peak occurred during November-December. In the first year the growth of mussel was fast, about 50% of its maximum size, and in subsequent years the growth decreased. The sizes attained by P. corrugata were 22, 36, 46, 51, 55 and 57 mm at the end of 1st to 6th years respectively. The average growth rates of P. corrugata from first to sixth years were 2.00 1.08, 0.75, 0.5, 0.25 and 0.17 mm/month respectively. The life span of the mussel was about 6 years at the study area. The von Bertalanffy growth equation for length was Lt = 60.76 [1- e-0.47 (t +0.0426)]. The growth performance index (Φ) was 3.896. The total mortality (Z) was 1.84/ year. The natural mortality (M) and fishing mortality (F) rates were 0.9 and 1.19/year respectively. The exploitation level (E) of P. corrugata was 0.57
Status of heavy metals in tissues of wedge clam, Donax faba (Bivalvia: Donacidae) collected from the Panambur beach near industrial areas
The wedge clam, Donax faba are edible bivalves and consumed as seafood. We found out the concentrations of Cu, Pb, Fe, Cr and Ni in the tissues of the wedge clams in coastal site, Panambur located along the south west coast of Karnataka. The concentrations of heavy metals in the samples were determined by atomic absorption spectrophotometer (AAS, GBC 932plus) working with an air acetylene flame. D. faba showed seasonal variations of metals accumulation with maximum concentrations during all seasons occurred in our study. The analysis of Fe content showed higher average concentrations for wedge clam collected from the study site. The concentration was in the order of Fe>Cu>Cr>Ni>Pb in our present study. The levels of heavy metals like Cu, Pb and Cr in the whole tissue of D. faba were below permissible limits except Ni. High concentrations of metals in the whole tissue of wedge clams collected may be derived from the industrial areas and a variety of anthropogenic activities
Seasonal changes in the biochemical composition of wedge clam, Donax scortum from the Padukere beach, Karnataka
Seasonal variations in protein, lipid and carbohydrate along with dry tissue weight and water in Donax scortum were studied for a period of 12 months (from February 2009 to January 2010). Water content remained at high level during monsoon and post monsoon periods. Dry tissue weight parentage exhibited an inverse relationship with water content in all months in the present study. Protein content was high relatively in all months except low during the breeding months. Glycogen content during the maturation period declined showing the utilization active gamete production. Fat content increased during the period of active formation of gametes. Afterwards, it decreased during the spawning period. Ash content in our present study shows similar seasonal pattern in percentages of lipids and proteins. However, changes in carbohydrate percentage show a completely different resulting in an inverse relationship between carbohydrate and protein. Calorific values of D. scortum are well within the known limits reported in the literatures for other bivalves. 
Mineralogy and Geochemistry of the Asanje Iron Ore Deposit within the Mayamaya-Hombolo Belt, Dodoma Region, Central Tanzania
This paper presents the mineralogy and chemical composition including iron ore impurities to ascertain its suitability for industrial applications. The Asanje iron ore deposit is hosted in Precambrian volcano-sedimentary rocks in the Mayamaya-Hombolo Belt in Dodoma region, within the Lake Nyanza Superterrane. Iron ores are found in two parallel ridges trending NW-SE. Ridge I occurs as vein and banded hematite-type ore and Ridge II as massive-type ore. A total of 24 ore samples were analysed for major and trace elements by XRF and petrographic studies by optical microscopy and XRD. The XRD results revealed that hematite and goethite are the main components and quartz is the gangue mineral in the iron ores. The XRF data shows the Fe2O3t content ranges from 20.8 to 87.3 wt% with an average of 52.7 wt%. The average concentrations in wt% of impurities such as SiO2, Al2O3, P2O5 and S are 37.9, 0.9, 1.2, and 0.2, respectively. By comparison, Ridge II has greater iron content (30.5–87.3 = Avg. 64.66 wt% Fe2O3t) than Ridge I (20.8–78.22 = Avg. 48.68 wt% Fe2O3t). Based on the chemical composition, the quality of iron ore is categorised as low to medium grade, and can be used in metallurgical and cement industries.
Keywords: Mineralogy, Geochemistry, Asanje Iron ore deposit, Mayamaya-Hombolo Belt, Tanzani
Factors influencing shell size and shape in Donax incarnatus (Gmelin) inhabiting Panambur sandy beach, Mangalore, India
475-483The samples of wedge clam Donax incarnatus (Gmelin), sediment and seawater were collected for a period of 12 months from Panambur sandy beach, near Mangalore. A total of 2258 individuals of D. incarnatus were subjected to analysis. The air (27.5-31.2 oC), sand (28.5-36 oC) and seawater (25-32.2 oC) temperatures showed seasonal fluctuations. The dissolved oxygen (3.29-4.55 ml L-1) and salinity (30.24-34.84 x 10-3) of seawaters showed variations. Fine sand dominated (75.09 to 94.2%) throughout the period of study, followed by medium sand (1.51 to 20.65%). The density (89 to 39446 no. m-2) and biomass (124 to 1892 g. m-2) of wedge clams showed marked variations during breeding season. Principal component analysis of biological variables and environmental parameters showed six components which together accounted for 90.39% of total variance. The component 1 (dissolved oxygen, density, biomass, wet weight, dry) accounted for 24.02% of total variance followed by component 2 (air, water and sediment temperatures, salinity and b values of length-breadth and length-dry weight relationships) for 20.64% of total variance and component 3 (mean shell length, mean shell breadth, mean shell width) for 17.27% of total variance. The rest of the variance of 28.46% was accounted for component 4 (medium sand, fine sand, very fine sand), component 5 (coarse sand, b value of length-wet weight relationship, b value of length-width relationship) and component 6 (silt & clay). The hierarchical cluster analysis produced a dendrogram with six sub-groups of clusters. The temporal variability of six factor scores was delineated using factor analysis
Cystic swellings of scrotum: Management
The cystic swellings of scrotum are one among the commonest clinical entities faced by a surgeon in day to day practice and a cause of concern to the patient more with his fertility. Presenting with varied etiology they can represent a wide range of medical issues. Gold standard for the management of such cystic swellings of scrotum continues to be surgical extirpation of the lesion. Objective: To identify the cause, mode of presentation, various modalities of treatment and outcome of these with their complications. Method: A total of 170 cases of cystic swellings of scrotum fulfilling the methodology criteria were subjected to the preformatted study. Diagnosis was mostly by clinical examination and supported by ultrasonography. All cases were treated surgically with the appropriate surgical procedure. Results: Maximum patients were in the age group of 31-50 years and presented with scrotal swelling (59%) and more commonly affecting the right side. The commonest cause for cystic swelling of the scrotum was primary vaginal hydrocele (55%). Surgical procedure using Lords Plication was found to be simple, effective and associated with minimum post operative complications; the other conventional techniques like Partial/sub-total excision of sac, everson of sac were associated with more complications like haematoma, scrotal edema and infection. Majority of patients were discharged on 7th Post-operative day. Conclusion: The present study, primary vaginal hydrocele was the commonest cystic swelling of scrotum and treated surgically showed good results. Lord’s procedure was associated with the less post-operative complications, minimal tissue handling and good haemostatic control
Robotic repair of giant paraesophageal hernias
BACKGROUND AND OBJECTIVES:
Giant paraesophageal hernia accounts for 5% of all hiatal hernias, and it is commonly seen in elderly patients with comorbidities. Some series report complication rates up to 28%, recurrence rates between 10% and 25%, and a mortality rate close to 2%. Recently, the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) has shown equivocal benefits when used for elective surgeries, whereas for complex procedures, the benefits appear to be clearer. The purpose of this study is to present our preliminary experience in robotic giant paraesophageal hernia repair. METHODS:
We retrospectively collected data from patients who had a diagnosis of giant paraesophageal hernia and underwent a paraesophageal hernia repair with the da Vinci Surgical System. RESULTS:
Nineteen patients (12 women [63.1%]) underwent surgery for giant paraesophageal hernia at our center. The mean age was 70.4 ± 13.9 years (range, 40-97 years). The mean American Society of Anesthesiologists score was 2.15. The mean surgical time and hospital length of stay were 184.5 ± 96.2 minutes (range, 96-395 minutes) and 4.3 days (range, 2-22 days), respectively. Nissen fundoplications were performed in 3 cases (15.7%), and 16 patients (84.2%) had mesh placed. Six patients (31.5%) presented with gastric volvulus, and 2 patients had other herniated viscera (colon and duodenum). There were 2 surgery-related complications (10.5%) (1 dysphagia that required dilatation and 1 pleural injury) and 1 conversion to open repair (partial gastric resection). No recurrences or deaths were observed in this series. CONCLUSION:
In our experience robotic giant paraesophageal hernia repair is not different from the laparoscopic approach in terms of complications and mortality rate, but it may be associated with lower recurrence rates. However, larger series with longer follow-up are necessary to further substantiate our results
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