Abstract: A retrospective study was undertaken to record the
occurrence and pattern of fractures in small animals (dogs and cats)
from year 2005 to 2010. A total of 650 cases were presented in small
animal surgery unit out of which of 116 (dogs and cats) were
presented with history of fractures of different bones. A total of
17.8% (116/650) cases were of fractures which constituted dogs 67%
while cats were 23%. The majority of animals were intact. Trauma in
the form of road side accident was the principal cause of fractures in
dogs whereas as in cats it was fall from height. The ages of the
fractured dog ranged from 4 months to 12 years whereas in cat it was
from 4 weeks to 10 years. The femoral fractures represented 37.5%
and 25% respectively in dogs and cats. Diaphysis, distal metaphyseal
and supracondylar fractures were the most affected sites in dog and
cats. Tibial fracture in dogs and cats represented 21.5% and 10%
while humoral fractures were 7.9% and 14% in dogs and cats
respectively. Humoral condyler fractures were most commonly seen
in puppies aged 4 to 6 months. Fractured radius-ulna incidence was
19% and 14% in dogs and cats respectively. Other fractures recorded
were of lumbar vertebrae, mandible and metacarpals etc. The
management comprised of external and internal fixation in both the
species. The most common internal fixation technique employed was
Intramedullary fixation in long followed by other methods like stack
or cross pinning, wiring etc as per findings in the cases. The cast
bandage was used majorly as mean for external coaptation. The
paper discusses the outcome of the case as per the technique
employed.
Abstract: Transpedicular screw fixation in spinal fractures,
degenerative changes, or deformities is a well-established procedure.
However, important rate of fixation failure due to screw bending,
loosening, or pullout are still reported particularly in weak bone stock
in osteoporosis. To overcome the problem, mechanism of failure has
to be fully investigated in vitro. Post-mortem human subjects are less
accessible and animal cadavers comprise limitations due to different
geometry and mechanical properties. Therefore, the development of a
synthetic model mimicking the realistic human vertebra is highly
demanded. A bone surrogate, composed of Polyurethane (PU) foam
analogous to cancellous bone porous structure, was tested for 3
different densities in this study. The mechanical properties were
investigated under uniaxial compression test by minimizing the end
artifacts on specimens. The results indicated that PU foam of 0.32
g.cm-3 density has comparable mechanical properties to human
cancellous bone in terms of young-s modulus and yield strength.
Therefore, the obtained information can be considered as primary
step for developing a realistic cancellous bone of human vertebral
body. Further evaluations are also recommended for other density
groups.
Abstract: In this paper, the construction of a detailed spine
model is presented using the LifeMOD Biomechanics Modeler. The
detailed spine model is obtained by refining spine segments in
cervical, thoracic and lumbar regions into individual vertebra
segments, using bushing elements representing the intervertebral
discs, and building various ligamentous soft tissues between
vertebrae. In the sagittal plane of the spine, constant force will be
applied from the posterior to anterior during simulation to determine
dynamic characteristics of the spine. The force magnitude is
gradually increased in subsequent simulations. Based on these
recorded dynamic properties, graphs of displacement-force
relationships will be established in terms of polynomial functions by
using the least-squares method and imported into a haptic integrated
graphic environment. A thoracolumbar spine model with complex
geometry of vertebrae, which is digitized from a resin spine
prototype, will be utilized in this environment. By using the haptic
technique, surgeons can touch as well as apply forces to the spine
model through haptic devices to observe the locomotion of the spine
which is computed from the displacement-force relationship graphs.
This current study provides a preliminary picture of our ongoing
work towards building and simulating bio-fidelity scoliotic spine
models in a haptic integrated graphic environment whose dynamic
properties are obtained from LifeMOD. These models can be helpful
for surgeons to examine kinematic behaviors of scoliotic spines and
to propose possible surgical plans before spine correction operations.
Abstract: Hysitron TriboIndenterTM TI 950 system has been
used for studying the local viscoelastic properties of porcine
intervertebral disc end plate by means of nanoscale mechanical
dynamic analysis. The specimen of an endplate was cut from fresh
porcine vertebra dissected from 16 month animal. The lumbar spine
motion segments were dissected and 5 millimeter thick plates of
vertebral body, endplate and annulus fibrosus were prepared for
nanoindentation. The surface of the sample was kept in physiological
solution during nanoindentation experiment. We obtained mechanical
characteristics of different areas of native endplate (endplate middle
and vertebra and annulus fibrosus boundary).
Abstract: For maintenance of a spine stability during the
postoperative period a transpedicular fixing of its elements is often
used. Usually the transpedicular systems are formed of rods which as
a result form a design of the frame type, fastening by screws to
vertebras. Such design should be rigid and perceive loadings
operating from the spine without essential deformations. From the
perfection point of view of known designs their stress
whole, and each of elements, in particular is of interest. In this study
the modeling of the transpedicular screw is performed and
estimation of its deformations taking into account interaction with a
vertebra body having variable structure is made.
Abstract: The posteroanterior manipulation technique is usually include in the procedure of the lumbar spine to evaluate the intervertebral motion according to mechanical resistance. The mechanical device with visual feedback was proposed that allows one to analysis the lumbar segments mobility “in vivo" facilitating for the therapist to take its treatment evolution. The measuring system uses load cell and displacement sensor to estimate spine stiffness. In this work, the device was tested by 2 therapists, female, applying posteroanterior force techniques to 5 volunteers, female, with frequency of approximately 1.2-1.8 Hz. A test-retest procedure was used for 2 periods of day. The visual feedback results small variation of forces and cycle time during 6 cycles rhythmic application. The stiffness values showed good agreement between test-retest procedures when used same order of maximum forces.
Abstract: The aim of the present study is to analyze the generation of osteoporotic vertebral bone induced by lack of calcium during growth period and analyze its effects for disc degeneration, based on biomechanical and histomorphometrical study. Mechanical and histomorphological characteristics of lumbar vertebral bones and discs of rats with calcium free diet (CFD) were detected and tracked by using high resolution in-vivo micro-computed tomography (in-vivo micro-CT), finite element (FE) and histological analysis. Twenty female Sprague-Dawley rats (6 weeks old, approximate weight 170g) were randomly divided into two groups (CFD group: 10, NOR group: 10). The CFD group was maintained on a refmed calcium-controlled semisynthetic diet without added calcium, to induce osteoporosis. All lumbar (L 1-L6) were scanned by using in vivo micro-CT with 35i.un resolution at 0, 4, 8 weeks to track the effects of CFD on the generation of osteoporosis. The fmdings of the present study indicated that calcium insufficiency was the main factor in the generation of osteoporosis and it induced lumbar vertebral disc degeneration. This study is a valuable experiment to firstly evaluate osteoporotic vertebral bone and disc degeneration induced by lack of calcium during growth period from a biomechanical and histomorphometrical point of view.
Abstract: Intradiscal and intervertebral pressure transducers
were developed. They were used to map the pressures in the nucleus
and within the annulus of the human spinal segments. Their stressrelaxation
were recorded over a period of time for nucleus
pressure, applied load, and peripherial strain against time. The
results show that for normal discs, pressures in the nucleus are
viscoelastic in nature with the applied compressive load.
Mechanical strains which develop around the periphery of the
vertebral body are also viscoelastic with the applied compressive
load. Applied compressive load against time also shows viscoelastic
behavior. However, annulus does not respond viscoelastically with
the applied load. It showed a linear response to compressive loading.
Abstract: Taking into account the importance of Lake Sevan and
Lake Sevan basin-s rivers for Armenian economy, the main goals of
our investigations were the documentation of water quality and the
biodiversity of invertebrates developed in Lake Sevan basin-s rivers
and selected tributaries.
Moderately satisfied ecological condition for the biodiversity of
Lake Sevan basin-s rivers has been established, and the changes in
species- composition of zoobenthos in Lake Sevan were detected.
A growing tendency of antibiotic resistance among E. coli isolates
in water resources has been shown.
Abstract: In the present study, changes of morphology and
mechanical characteristics in the lumbar vertebrae of the
ovariectomised (OVX) rat were investigated. In previous researches,
there were many studies about morphology like volume fraction and
trabecular thickness based on Micro - Computed Tomography (Micro
- CT). However, detecting and tracking long-term changes in the
trabecular bone of the lumbar vertebrae for the OVX rat were few. For
this study, one female Sprague-Dawley rat was used: an OVX rat. The
4th Lumbar of the OVX rat was subjected to in-vivo micro-CT.
Detecting and tracking long-term changes could be investigated in the
trabecular bone of the lumbar vertebrae for an OVX rat using in-vivo
micro-CT. An OVX rat was scanned at week 0 (just before surgery), at
week 4, at week 8, week 16, week 22 and week 56 after surgery. Finite
element (FE) analysis was used to investigate mechanical
characteristics of the lumbar vertebrae for an OVX rat. When the OVX
rat (at week 56) was compared with the OVX rat (at week 0), volume
fraction was decreased by 80% and effective modulus was decreased
by 75%.
Abstract: Artemia is one of the most conspicuous invertebrates
associated with aquaculture. It can be considered as a model
organism, offering numerous advantages for comprehensive and
multidisciplinary studies using morphologic or molecular methods.
Since DNA extraction is an important step of any molecular
experiment, a new and a rapid method of DNA extraction from adult
Artemia was described in this study. Besides, the efficiency of this
technique was compared with two widely used alternative techniques,
namely Chelex® 100 resin and SDS-chloroform methods. Data
analysis revealed that the new method is the easiest and the most cost
effective method among the other methods which allows a quick and
efficient extraction of DNA from the adult animal.
Abstract: Amount of dissolve oxygen in a river has a great direct affect on aquatic macroinvertebrates and this would influence on the region ecosystem indirectly. In this paper it is tried to predict dissolved oxygen in rivers by employing an easy Fuzzy Logic Modeling, Wang Mendel method. This model just uses previous records to estimate upcoming values. For this purpose daily and hourly records of eight stations in Au Sable watershed in Michigan, United States are employed for 12 years and 50 days period respectively. Calculations indicate that for long period prediction it is better to increase input intervals. But for filling missed data it is advisable to decrease the interval. Increasing partitioning of input and output features influence a little on accuracy but make the model too time consuming. Increment in number of input data also act like number of partitioning. Large amount of train data does not modify accuracy essentially, so, an optimum training length should be selected.
Abstract: The present investigation aimed to study the
histomorphometric characterizations of the thyroid gland of the duck.
Five adult male and five adult female ducks were used in the
experiment. Results showed that the overall histological structure of
the thyroid gland of the duck were similar to those of the other
vertebrae. The gland consisted of roughly spherical randomly
distributed micro and macrofollicles with very little interstitial tissue
between them. Each follicle is lined by a single layer of epithelial
cells enclosing a cavity, the follicular cavity, which is filled with
colloid. Ultrastructural findings showed that the apical surface of the
follicular cells bears a variable number of short, irregularly
distributed microvilli which are apparently more numerous on the
columnar cells than on the lower, relatively inactive cells.
Mitochondria and rough endoplasmic reticulum occupy the
subnuclear region of the follicular cell, whereas the Golgi complex,
free ribosomes and colloid droplets were found in the apical
cytoplasm. At light or electron microscopic levels, there was no sex
difference in histomorphometric characteristics of the thyroid
glands.ls.
Abstract: During the past decade, pond aeration systems have
been developed which will sustain large quantities of fish and
invertebrate biomass. Dissolved Oxygen (DO) is considered to be
among the most important water quality parameters in fish culture.
Fishponds in aquaculture farms are usually located in remote areas
where grid lines are at far distance. Aeration of ponds is required to
prevent mortality and to intensify production, especially when
feeding is practical, and in warm regions. To increase pond
production it is necessary to control dissolved oxygen. Artificial
intelligence (AI) techniques are becoming useful as alternate
approaches to conventional techniques or as components of
integrated systems. They have been used to solve complicated
practical problems in various areas and are becoming more and more
popular nowadays. This paper presents a new design of diffused
aeration system using fuel cell as a power source. Also fuzzy logic
control Technique (FLC) is used for controlling the speed of air flow
rate from the blower to air piping connected to the pond by adjusting
blower speed. MATLAB SIMULINK results show high performance
of fuzzy logic control (FLC).