153 research outputs found
Sampling and Reconstruction of Shapes with Algebraic Boundaries
We present a sampling theory for a class of binary images with finite rate of
innovation (FRI). Every image in our model is the restriction of
\mathds{1}_{\{p\leq0\}} to the image plane, where \mathds{1} denotes the
indicator function and is some real bivariate polynomial. This particularly
means that the boundaries in the image form a subset of an algebraic curve with
the implicit polynomial . We show that the image parameters --i.e., the
polynomial coefficients-- satisfy a set of linear annihilation equations with
the coefficients being the image moments. The inherent sensitivity of the
moments to noise makes the reconstruction process numerically unstable and
narrows the choice of the sampling kernels to polynomial reproducing kernels.
As a remedy to these problems, we replace conventional moments with more stable
\emph{generalized moments} that are adjusted to the given sampling kernel. The
benefits are threefold: (1) it relaxes the requirements on the sampling
kernels, (2) produces annihilation equations that are robust at numerical
precision, and (3) extends the results to images with unbounded boundaries. We
further reduce the sensitivity of the reconstruction process to noise by taking
into account the sign of the polynomial at certain points, and sequentially
enforcing measurement consistency. We consider various numerical experiments to
demonstrate the performance of our algorithm in reconstructing binary images,
including low to moderate noise levels and a range of realistic sampling
kernels.Comment: 12 pages, 14 figure
Shapes From Pixels
Continuous-domain visual signals are usually captured as discrete (digital)
images. This operation is not invertible in general, in the sense that the
continuous-domain signal cannot be exactly reconstructed based on the discrete
image, unless it satisfies certain constraints (\emph{e.g.}, bandlimitedness).
In this paper, we study the problem of recovering shape images with smooth
boundaries from a set of samples. Thus, the reconstructed image is constrained
to regenerate the same samples (consistency), as well as forming a shape
(bilevel) image. We initially formulate the reconstruction technique by
minimizing the shape perimeter over the set of consistent binary shapes. Next,
we relax the non-convex shape constraint to transform the problem into
minimizing the total variation over consistent non-negative-valued images. We
also introduce a requirement (called reducibility) that guarantees equivalence
between the two problems. We illustrate that the reducibility property
effectively sets a requirement on the minimum sampling density. One can draw
analogy between the reducibility property and the so-called restricted isometry
property (RIP) in compressed sensing which establishes the equivalence of the
minimization with the relaxed minimization. We also evaluate
the performance of the relaxed alternative in various numerical experiments.Comment: 13 pages, 14 figure
Association of ADRB2 rs1042713 with Obesity and Obesity-Related Phenotypes and Its Interaction with Dietary Fat in Modulating Glycaemic Indices in Malaysian Adults
Gene-diet interaction studies have reported that individual variations in phenotypic traits may be due to variations in individual diet. Our study aimed to evaluate (i) the association of ADRB2 rs1042713 with obesity and obesity-related metabolic parameters and (ii) the effect of dietary nutrients on these associations in Malaysian adults. ADRB2 genotyping, dietary, physical activity, anthropometric, and biochemical data were collected from 79 obese and 99 nonobese individuals. Logistic regression revealed no association between ADRB2 rs1042713 and obesity (p = 0.725). However, the carriers of G allele (AG + GG genotypes) of rs1042713 were associated with increased odds of insulin resistance, 2.83 (CI = 1.04â7.70, adjusted p = 0.042), in the dominant model, even after adjusting for potential confounders. Obese individuals carrying the G allele were associated with higher total cholesterol (p = 0.011), LDL cholesterol levels (p = 0.008), and total cholesterol/HDL cholesterol ratio (p = 0.048), compared to the noncarriers (AA), even after adjusting for potential confounders. Irrespective of obesity, the carriers of GG genotype had significantly lower fasting glucose levels with low saturated fatty acid intake (<7.3% of TE/day) (4.92 ± 0.1 mmol/L vs 5.80 ± 0.3 mmol/L, p = 0.011) and high intake of polyunsaturated fatty acid:saturated fatty acid ratio (â„0.8/day) (4.83 ± 0.1 mmol/ L vs 5.93 ± 0.4 mmol/L, p = 0.006). Moreover, the carriers of GG genotype with high polyunsaturated fatty acid intake (â„6% of TE/day) had significantly lower HOMA-IR (1.5 ± 0.3 vs 3.0 ± 0.7, p = 0.026) and fasting insulin levels (6.8 ± 1.6 ”U/mL vs 11.4 ± 2.1 ”U/mL, p = 0.036). *ese effects were not found in the noncarriers (AA). In conclusion, G allele carriers of ADRB2 rs1042713 were associated with increased odds of insulin resistance. Obese individuals carrying G allele were compromised with higher blood lipid levels. Although it is premature to report gene-diet interaction on the regulation of glucose and insulin levels in Malaysians, we suggest that higher quantity of PUFA-rich food sources in regular diet may benefit overweight and obese Malaysian adults metabolically. Large-scale studies are required to replicate and confirm the current findings in the Malaysian population
The effect of increasing blood flow rate on dialysis adequacy in hemodialysis patients
Background and aim: One of the morbidity and mortality determinants of the dialysis patients is inadequacy of dialysis. Increasing the dialysis efficacy improves patientâs prognosis. The aim of this study was to assess the effect of increasing blood flow on the adequacy of dialysis in dialysis department of Ekbatan hospital of Hamadan. Methods: This before-after desigh study was performed on 42 patients. First, data was collected about the following parameters: patientâs weight before and after hemodialysis, ultrafiltration, urea before and after hemodialysis, the time of dialysis, percentage of filter clearance and speed of dialysate. Then the patient was attached to the dialysis machine and a sample of blood was taken. The pumpage of dialysis machine in the first session was put on 200 ml/min and in the second session on 250 ml/min. During the hemodialysis, the hemodynamic status and vital signs of patientâs were controlled. When hemodialysis finished a blood sample was taken from the artery set, in a section before dialyzer (4 blood sample for each patients), weight was controlled again and the sample was sent to a laboratory for urea control. Then the efficiency of dialysis was determined. Descriptive and analytical statistics were used for analysis of the data. Results: Results showed the mean KT/V (K=Clearance dialyzer T= Time V=Volume of distribation of urea) of patients whose pumping cycle were 200 ml/min, had 0.943±0.335 and URR (Urea Reduction Ratio) 53.3±13.5 wereas mean KT/V patients with 250 pumping cycle had 1.195±0.45 and URR 60.17±10.47. Paired t-test with %95 confidence interval showed that there was a significant difference in dialysis efficiency between the two groups (p<0.05). Conclusion: Our data suggests that increasing blood flow rate by 25% of previous flow rate is effective in achieving higher dialysis adequacy in hemodialysis patients
Interdisciplinary education of social accountability in short-term workshops of Shiraz University of Medical Sciences
Background: Accountability refers to a set of concepts and social actions by which individuals or organizations have a sense of commitment to explain and to justify their behavior towards the others. Since it is one of the overall objectives of each university, the present study conducted to evaluate the effect of interdisciplinary education of social accountability in short-term workshops on medical studentâs knowledge. Methods: The present study followed a qualitative-quantitative method with the qualitative stage conducted as group interview. In the first phase, eight faculty members were selected in order to determine the scope and the main topics of social accountability. The second phase was training workshops of social accountability using intervention method. Before and after the course, the knowledge of concepts was assessed using a valid and reliable questionnaire. Results: The main scope and criteria of the social accountability were extracted based on the results of the expertsâ group discussion in eight items. The results of investigating the quality of the workshops revealed the studentâs satisfaction of the quality of presentations (88%), the appropriate time management (86%), and the new information (85%). Also, the results of the second phase demonstrated the educational effectiveness of social responsibility in the studentâs comments (pretest Mean±SD=13.86 and posttest Mean±SD=14.80, P=0.002). The results of the workshop showed a significant effect of social accountability education on the participants. Conclusion: The students comprehended the purposes of the application. So, the probability of changing the behavior in medical students is possible with the clinical perspective. However, the stability of this achievement needs sufficient enforcement.Â
Knowledge, attitude and practice of Iranian people regarding the use of antibiotics and its resistance
Objective and Background
The aim of this study was so assess the knowledge and attitude of the people in Iran regarding the antibacterial resistance caused by antibiotics.
Introduction
increasing concern toward antibiotic resistance led to many researches on the causes of this issue. The public awareness plays a critical role, according to the studies. Another important factor is the attitude of the people regarding the antibiotic use and the effect of their behavior on its resistance. The practice of each individual patient may contribute to the antibiotic resistance and major health problems and increased rate of death.
materials and method
A questionnaire based survey was carried out among the female population of 1000 in Tehran, Iran. An intervention course was carried out, training the volunteers. After the completion of the training course, the volunteers had to take another test to asses the effect of the training on the knowledge, attitude and practice of people regarding the antibiotic use.
results and discussion
Before the course, people considered antibiotic as safe drugs, therefore taking them without prescription and the malpractice was evident from the incomplete course of treatment. There was a significant difference indicating the effect of the course on the public awareness and their attitude which may lead to better practice regarding antibiotic use. There may be other contributing factors to the malpractice such as financial status and experience of no significant toxicity of the drugs, making them an optimum prevention or treatment option, according to the public. This intervention was successful regrading the attitude of the people, but long term studies are required to assess them in practice
Design and Evaluation of the âPreparation Course for New Entrant Assistantsâ on the Awareness and Skills of Newly Arrived Surgery Resident
Background: Beginning of assistance course is associated with anxiety. This due to unfamiliarity with the assistance and insufficient training, knowledge, and required skills. The aims of this study were to design, implement and evaluate the effects of a period of 1-month as âpreparation course for new entrant assistantsâ on the awareness and skills of newly arrived residents.Methods: 12 newly arrived assistant student were divided into two equal groups. Some steps such as understanding the environment and legislation, education about an emergency, and dealing with patients and also, suturing, chest tube insertion, and cut down skills were passed by the first group before starting the assistance course. The second group was entered in the assistance course without this preparation course. For performance evaluation and comparison of these two groups, four questionnaires were created and filled consequently before the entrance, at the end of the 2nd month, based on direct observation of procedural skills (DOPS) exam, and at the end of 6th month.Results: There were no significant differences between two groups at the beginning of the study (P < 0.05). At the end of the 2nd month, the first group had better performance in understanding the environment, patient examination, diagnosis and emergency skills in comparison to the second group (P < 0.05). Based on the DOPS score, the first group had significantly better performance (P < 0.05) except in performing cut-down (P > 0.05). Also procedure, the first group was better than the second group just in the consensus of the procedure (P < 0.05). Finally, at the end of the 6th month, the difference between two groups was becoming lower, and supervisors believed that after additional 3 months, this difference would be lost.Conclusions: Conducting a 1-month period of preparation for new entrant assistants can be useful in increasing awareness, understanding the environment, performance, the knowledge of the theory and how to deal with patients as well as increase their skills in performing the expected procedures
Classification and identification of human papillomavirus based on its prevalence and development of cervical lesion among Iranian women
Introduction: Cervical cancer is the most common female cancer in large areas of the developing world, and almost half of these cases (54%) arises in Asia, where cervical cancer is still threatening womenâs health and survival, which makes it a considerable public problem. Human papillomavirus (HPV) is one of the most powerful human carcinogens. Today, it has been proven that all cervical cancers and primary precancerous lesions are caused by carcinogenic types of HPV infections. HPV genotyping can therefore evaluate the screening programs. Methods: Five hundred fifty women referring to the gynecological centers were subjected to Pap smear cell samples. The cytopathological diagnosis of obtained cervical samples was based on the Bethesda system. HPV genotyping was carried out using the INNO-LiPA HPV Genotyping Extra II Amp assay. Results: In a total of 244 HPV positive cases, singleâtype HPV infecÂtion was observed in 49.6%, while multiâtype HPV infections (including â„ 2 types) were found in 45.5% of cases. Among the 110 cases with abnormal cytology results, going-over analyses led to the identification of atypical squamous cell of unknown significance (ASCUS) in 73 cases, lowâgrade squamous intraepithelial lesions (LSIL) in 24 cases, and highâgrade squamous intraepithelial lesion (HSIL) in 12 cases. In these groups, the infection rate of high-risk HPV (HR-HPV) was 89%, 82%, and 100%, respectively. Conclusion: In this study, the total population of women suffering from different cervical lesions and malignancy was found to be infected with various HPV genotypes. High prevalence of HPV- 53 and HPV- 16 detected among participants with normal cytology can be considered as a tip-off development of cervical cancer among Iranian women
Develop talents to increase productivity: report of the ninth national medical science olympiad in Islamic Republic of Iran in year 2017
Dear Editor, Extracurricular activities for the gifted and
talented students in Iran derive from the
belief that students with high potentials are
expected to make great help for the health
care of the community. One of these activities
is holding medical science Olympiads. In the
previous meeting report about medical science
Olympiad in year 2011, a unique experience
of Islamic Republic of Iran was reported. The
Olympiad was held in three areas of basic
sciences, clinical reasoning and management by
participation of high rank medical students from
all over the country in two stages: individual and
group (1-4).
After performing 8 Olympiads in the country,
the ninth Olympiad was held in September 2017
in Tehran, Iran differently with more emphasis
on creativity and productivity.
While creativity in health care is mostly
supposed to be innovations in surgical devices,
medications, and procedures, we believed that it
also relates to other health care disciplines like
basic sciences, medical education, philosophy of
medicine and management. Creativity in these
fields is a newer concept that may result in finding
novel solutions to health care and educational
problems and challenges such as improving
patient care and coordinating care across multiple
disciplines and difficult conditions.
Shahid Beheshti University of Medical
Sciences was the host of the Ninth National
Medical Science Olympiad in September 2017
under direct supervision of Ministry of Health
and Medical Education. This Olympiad was held
in five areas including basic sciences, clinical
medicine, medical education, philosophy of
medicine and health care management. All top
ranked students in medical sciences (such as
medicine, pharmacy, nursing, health management,
dentistry, etc.) from all over the country had the
chance of participating in this Olympiad. In Iran
integration of medical education and health care
delivery system has started in 50 universities of
medical sciences all over the country (5). 2151
students from these universities participated in
the individual Olympiad exam. Then 30 teams
in each of the five areas (total 450 teams) were
selected 55 experts in five scientific committees
constructed the Olympiad questions in individual
and team stages. A unique experience in the Ninth
Olympiad was using a novel and creative project
based assignment for each team in each of the
five areas. These projects were Evidence-based
decision making, public private partnership, early
clinical exposure, medical futility and autonomic
modulation on the brain functional connectivity
related to depression.
75 percent of the students stated that they
were satisfied with these innovative and creative
projects in different areas. 84 percent of the
faculties reported that this kind of Olympiad
increased studentsâ motivation and led them
to compare issues friendly with each other in
a scientific environment. 69.25 percent of the
students reported that increasing the number
of teams in this Olympiad for problem solving
activities was a very good experience for them
and ascertained that such activities should be
included in the formal curriculum of medical
schools.
The main shortcoming in this Olympiad
reported by the students was the competitive
nature of the exam and subjectivity in scoring
the projects in some areas.
Performing such Olympiads is essential in
discovering talented students and developing
their capabilities to promote health systems.
Although academic merit is not the only
indicator of success in health science disciplines,
designing additional programs for gifted and
talented students is warranted to help academically
talented students to further their knowledge
Healthcare Staffâs Attitude toward the E-learning On-the-job Courses and its Association with Self-Assessment Effectiveness of these Programs
Background: Healthcare workers are frequently too preoccupiedwith their jobs to attend regular educational sessions. E-learning isone of the most effective ways to empower healthcare workers andbetter utilize their skills. In the present study, we aimed to measurethe correlation between the attitude toward E-learning and teachingeffectiveness through self-assessment after the E-learning coursesfor healthcare staff.Methods: In this cross-sectional study, all the healthcare staff workingin Bushehr urban healthcare center, Bushehr, Iran, were enrolled viathe census sampling method from April to June 2019 (n=219). Thetopics covered in the E-learning courses were poisoning, introductionto the pre-hospital management system, occupational risks, infectioncontrol, and psychological wellbeing. We used the Attitude towardE-learning questionnaire, consisting of 20 questions, in addition toSelf-assessment of Teaching Effectiveness questionnaire, comprising35 questions. SPSS software version 21 was utilized for data analysis.Results: Overall, 102 (46.6%) men and 117 (53.4%) women wereenrolled in the study. The total mean score of the attitude towardE-learning on-the-job courses was 62.86±6.14 and the total meanscore of self-assessment of teaching effectiveness was 115.4±26.75.According to the obtained results, there was a weak, positive,significant correlation between these two scores (r=0.20, P=0.003).The mean score of the attitude toward E-learning on-the-job courseswas significantly lower in the high-educated staff in comparisonwith that in the other staff (P<0.001).Conclusion: We observed a higher score for attitude towardE-learning on-the-job courses among the health care staff comparedwith the score of self-assessment of teaching effectiveness. In orderto create a positive attitude in employees about virtual courses,policymaking can contribute to increasing the effectiveness of thosecourses and improving employee performance
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