A porous fibrous hyperelastic damage model for human periodontal ligament: Application of a microcomputerized tomography finite element model

The periodontal ligament (PDL) is a soft biological tissue that connects the tooth with the trabecular bone of the mandible. It plays a key role in load transmission and is primarily responsible for bone resorption and most common periodontal diseases. Although several numerical studies have analysed the biomechanical response of the PDL, most did not consider its porous fibrous structure, and only a few analysed damage to the PDL. This study presents an innovative numerical formulation of a porous fibrous hyperelastic damage material model for the PDL. The model considers two separate softening phenomena: fibre alignment during loading and fibre rupture. The parameters for the material model characterization were fitted using experimental data from the literature. Furthermore, the experimental tests used for characterization were computationally modelled to verify the material parameters. A finite element model of a portion of a human mandible, obtained by microcomputerized tomography, was developed, and the proposed constitutive model was implemented for the PDL. Our results confirm that damage to the PDL may occur mainly because of overpressure of the interstitial fluid, while large forces must be applied to damage the PDL fibrous network. Moreover, this study clarifies some aspects of the relationship between PDL damage and the bone remodelling process

Arsenic Induced Toxicity in Broiler Chicks and Its Amelioration with Ascorbic Acid: Clinical, Hematological and Pathological Study

This study was conducted to observe the arsenic (As) toxicity lesions in birds and to know either Vit C ameliorates these toxic effects or not. One-day-old broilers chicks (n=72) procured from a local hatchery were randomly divided into four equal groups. First group was kept as control and second group was given As (50 mg/kg BW) via crop tubing. Third group received in addition to As, Vit C (250 mg/kg BW) whereas fourth group received only Vit C. Killing by neck dislocation of randomly selected six birds from each group was carried out on experimental days 0, 16 and 32 for collection of blood and tissues specimens. Arsenic treated birds showed clinical signs of toxicity throughout the experiment than all other groups. These clinical signs included decreased body weight and feed intake, dullness, open mouth breathing, increased thirst, ruffled feathers, pale comb, skin irritation and watery diarrhea which were not significant in any other group. As treated group showed a significant (P<0.05) decrease in hematological parameters. Severe gross and histopathological changes were observed in intestines, spleen and lungs of birds fed with As than all other groups. Decreased height of villi of middle portion of small intestines was also observed in As treated birds. Villi height in Vit C treated group increased as compared to control group. It was concluded that As induces severe toxic effects in broiler birds; however, these toxic effects can be partially ameliorated by Vit C

A design of experiments (DoE) approach to identify the influencing parameters that determine poly-D,L-lactic acid (PDLLA) electrospun scaffold morphologies

Electrospun fibrous materials have increasing applications in regenerative medicine due to the similarity of fibre constructs to the morphology of certain extracellular matrices. Although experimentally the electrospinning method is relatively simple, at the theoretical level the interactions between process parameters and their influence on the fibre morphology is not yet fully understood. Here, we hypothesised that a design of experiments (DoE) model could determine combinations of process parameters that result in significant effects on poly-D,L-lactic acid (PDLLA) fibre morphology. The process parameters used in this study were applied voltage, needle-to-collector distance, flow rate and polymer concentration. Data obtained for mean fibre diameter, standard deviation of the fibre diameter (stdev, measure of fibre morphology) and presence of 'beading' on the fibres (beads per µm2) were evaluated as a measure of PDLLA fibre morphology. Uniform fibres occurred at standard deviations of ≤ 500 nm, 'beads-on-string' morphologies were apparent between ± 500-1300 nm and large beads were observed at ± 1300-1800 nm respectively. Mean fibre diameter was significantly influenced by the applied voltage and interaction between flow rate and polymer concentration. Fibre morphology was mainly influenced by the polymer concentration, while bead distribution was significantly influenced by the polymer concentration as well as the flow rate. The resultant DoE model regression equations were tested and considered suitable for the prediction of parameters combinations needed for desired PDLLA fibre diameter and additionally provided information regarding the expected fibre morphology

Estimation of hormone residuals (B-Estradiole) in rainbow trout

Residual level of 17- Beta Stradiol and progesterone hormones in rainbow trout fish plasma were measured during different period using RIA method. Blood sampling from abdominal aorta were taken from 70 individual of female fishes (100±11 g) which had been exposed to hormone at 0.5, 1,2,4,8,12,24 and 168 h (7 groups) compared with control group which was not exposed to this hormone. Results showed that plasma hormones measurement in different fish groups after exposing had significant differences (P<0.01) and the highest and lowest 17-Beta Stradiol hormone residue were observed in fishes that exposed 0.5h and 168h to hormone respectively (121±9 ng. ml^-1 and 3±0.9 ng. ml^-1) but there is no any differences between fishes exposed 168h to hormone and control group. Also the highest progesterone hormone level were measured in fishes 0.5 an 1h exposed and the lowest one was in fishes 168 h exposed. The range of progesterone hormone were between 0.3 to 1.1 ng .ml^-1 and significant increasing of this hormone levels were obtained in fishes exposed to hormone 4 to 24h (P<0.01). As consequence these hormone can not residue in fishes for a long time and maximum after one week the levels back to the normal

A suggested new bacteriophage genus: “Viunalikevirus”

We suggest a bacteriophage genus, “Viunalikevirus”, as a new genus within the family Myoviridae. To date, this genus includes seven sequenced members: Salmonella phages ViI, SFP10 and ΦSH19; Escherichia phages CBA120 and PhaxI; Shigella phage phiSboM-AG3; and Dickeya phage LIMEstone1. Their shared myovirus morphology, with comparable head sizes and tail dimensions, and genome organization are considered distinguishing features. They appear to have conserved regulatory sequences, a horizontally acquired tRNA set and the probable substitution of an alternate base for thymine in the DNA. A close examination of the tail spike region in the DNA revealed four distinct tail spike proteins, an arrangement which might lead to the umbrella-like structures of the tails visible on electron micrographs. These properties set the suggested genus apart from the recently ratified subfamily Tevenvirinae, although a significant evolutionary relationship can be observed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00705-012-1360-5) contains supplementary material, which is available to authorized users

Evaluation of sperm quality and different nutrient levels on sperm efficiency in male rainbow trout

Considering the importance of rainbow trout (Oncorhynchus mykiss) in supplying required protein of people and effort to increase the efficiency of these fish reproduction, some related factors such as sperm quality and potential fertility of male are necessary. The aim of this study was to find out the effects of different dosages of Arginine on the biochemical parameters (including LDH, AST, ALT, ALP, iron, magnesium, phosphorous, chloride, calcium, sodium, Potassium, cholesterol, uric acid, urea, fructose, glucose, total protein and pH) of rainbow trout seminal plasma. For this purpose, five practical diets (each consisting of 3 triplicates) were supplemented with Arginine at 0.00 (Control), 0.50, 1.00, 1.50 and 2.00%. Broodstock feed last for 90 days. At the end of the feeding period one fish was captured from each replicate in order to collect their semen. Results indicate that there were no significant differences in LDH, ALP, Fe^2+ and P content among different treatments. The lowest level of AST and ALT and the highest level of Ca^2+ and Mg^2+ ions were observed in the treatment fed with 1.50% of Arginine which showed significant differences with other treatments (p<0.05). Moreover, the amount of Cl^-, Na^+ and K^+ ions were significantly increased in the seminal plasma in fish which were fed on diets containing arginine in comparison to control. As the amount of Arginine were increased, the levels of uric acid stepped up significantly in contrast to the urea and glucose. The highest amounts of cholesterol, fructose and total protein were observed in the treatments fed on 2.00, 0.50 and 1.00% of Arginine, respectively, that showed significant differences with other treatments (p<0.05). The highest pH value was assayed in the 1.50% of Arginine treatment. The results of the Pearson correlation coefficient showed a significant positive correlation between Ca^2+ and Mg^2+ ions and Na^+ with K^+ and Clions (r=0.750, r=0.769 and r= 0.938, p<0.01), respectively. On the other hand, a significant negative correlation between cholesterol with Cl^-, Na^+, K^+, ALT and LDH (r=- 0.764, r=-0.724 and r=-0.728, p<0.01) and (r=-0.531 and r=-0.560, p<0.05) and also a significant positive correlation between K^+ and Clions (r=0.836, p<0.01) were observed. Finally, it can be expressed that the levels of most of the ions were increased and there was a reduction in the levels of enzymes in seminal plasma of fish which were fed with practical diet including 1.5% of Arginine. So it can be recommended that adding this value of Arginine to the diets of rainbow trout broodstock, would improve the sperm quality which results in the enhancement of efficiency in rainbow trout reproduction

Genetic improvement of rainbow trout in Iran

Inthisstudy, Iranian and French male and female Oncorhynchus mykiss broodstocks were invided into two groups 50 and 24 respectivelyin Research center of genetic and breeding of coldwater fishers, Yasouj,Iran and the genetic structure of them was investigated using 6 microsatellite markers. Along with broodstock maturation, fertilization 1:1(female:male) were randomly assigned and occurred in25 of12Iranian andFrench treatment respectively. Reproductive parameters were recordedfor the whole family.Average number of observed alleles in Iranian and French stocks was 6.68 and 6.83, respectively.Average number of effective alleles in Iranian and French stocks was 3.13 and 3.45 respectively.Fixation index Fstwas calculated based on allelic frequency between two stocks was 0.058 with significant difference between 2 stocks. Eyed percentage for french broodstock calaulated zero and deleted. Fertilization rate(100-0), the eyed percentage (98-0), The hatch rate(98- 0),the averagefecundity4114.708, the average eggs size 4.88 mm, Survivalinthe first three months 19-73% calculated for Iranian broodstocks. Considering the quality of eggs and larvaeat different stages and selection between the different family and the within family remained 10 treatments and are keptas future broodstocks. Therelationship between fecundity-egg size, fecundity-weight, fecundity-length, egg sizeweightwas performed using regression. The results showed that Fecundity wasinfluenced more byweight and productivelength. The research is beginning to IDthe broodstockin our country

User Experience Study of Multiple Photo Streams Visualization

With the expansion of digital photographic content stored online and concurrent proliferation of capturing devices, the management and visualization of personal photo collections have become very challenging tasks. In order to gain insight into novel ways of handling and representing large personal photo collections, this paper presents results of a user experience study into novel visualizations of multiple photo streams, sourced from different individuals or capture devices. A web-based application prototype was designed and implemented offering synchronized visualization of photo streams in a single- or multi-window display layout. An experimental study was conducted with 20 users, and the results demonstrate high user demand for concurrent presentation of multiple media streams as well as recommends methods for leveraging its potential

4streams: An ambient photo sharing application for extended families

In this paper we describe a novel photo sharing system called 4streams. This is an ambient photo display that allows a small group of users to keep in touch through a kind of visual twitter feed of concurrent photographs from their mobile phones. The photographs of up to four users are displayed in a dynamic collage in the four quadrants of a dedicated ambient display, with photographs to each quadrant arriv- ing in real time as photographs are taken/uploaded. His- torical photos can also be browsed or played back in lock- step with each other, as a reminder of what each member of the group was doing over the same period of time. The system was trailed over seven weeks by an extended family distributed over three countries. The findings suggest that the system increases the social connection and presence be- tween children, parents and grandparents of an intergenera- tional family living apart. This was not only through ’visual status’ images of family members living in different places, but also through updates of collocated members travelling away from home, and deliberately crafted images designed to elicit responses or trigger discussions in other media. The implications of these findings for theories of photo sharing are discussed