Memory and mutualism in species sustainability: a time-fractional Lotka-Volterra model with harvesting

We first present a predator-prey model for two species and then extend the model to three species where the two predator species engage in mutualistic predation. Constant effort harvesting and the impact of by-catch issue are also incorporated. Necessary sufficient conditions for the existence and stability of positive equilibrium points are examined. It is shown that harvesting is sustainable, and the memory concept of the fractional derivative damps out oscillations in the population numbers so that the system as a whole settles on an equilibrium quicker than it would with integer time derivatives. Finally, some possible physical explanations are given for the obtained results. It is shown that the stability requires the memory concept in the model

A qualitative study of the experiences of Iranian infertile couples after unsuccessful assisted reproductive technologies

Objectives: Assisted reproductive technologies (ARTs) give hope to some infertile couples; however, in vitro fertilization (IVF) is expensive and not subsidized by the Iranian state. More than 75% of IVF cycles in Iranian couples are unsuccessful. The aim of this paper is to describe the experiences of Iranian infertile couples after unsuccessful treatment. Materials and Methods: In this descriptive qualitative study, 36 participants including 29 Iranian infertile couples recruited after unsuccessful ART treatments, five infertility treatment team members and 2 relatives of infertile couples were interviewed at an Infertility Center in Northeastern Iran from April 2016 to June 2017. Data were collected using semi-structured, face-to-face interviews. Data analysis was carried out following Sandelowski. Results: Iranian infertile couples’ experiences following failed ART cycles are described. The findings presented here show that Iranian infertile couples experience stressors during treatment cycles and systemic challenges which may be unique to the Iranian cultural context. Conclusions: Iranian infertile couples face particular challenges related to the cultural context in which ARTs are delivered. Further exploration of the effects of culture on the experiences of failed ARTs needs to be considered by infertility clinics in Ira

Surgical suturing training with virtual reality simulation versus dry lab practice: an evaluation of performance improvement, content, and face validity

The purpose of this study is to evaluate the effectiveness of virtual reality (VR) simulation versus dry lab suturing practice at improving suturing performance in robotic surgery. Nineteen novice participants with no prior robotic suturing experience were randomized to two groups, VR simulation and dry lab, which consisted of inanimate training on a da Vinci Si surgical system. Each group underwent baseline suturing evaluation, then trained on the Simbionix™ Suturing Module (SSM) or undertook suturing practice using the da Vinci Surgical System in a dry lab. Final suturing performance was evaluated using the objective suture scoring method. Participants in the VR simulation group were surveyed to assess the face and content validity of the SSM. Both groups experienced significant improvement after training (VR simulation group p = 0.0078; dry lab group p = 0.0039). There was no significant difference in improvement between the two groups after undergoing training with either SSM or in the dry lab. Improvements in composite timing scores were 123 and 172 in the VR simulation and dry lab test groups, respectively (p = 0.36). Face validation varied with respect to the category assessed, but participants confirmed content validity of the SSM in all categories. In this sample of novice operators, there was no significant advantage in training with VR simulation using the SSM over dry lab training in improving suturing performance. Users of the SSM found it useful and relevant as a training tool for improving suturing performance

Iranian infertile couples' strategies to manage social interactions after unsuccessful treatments with assisted reproductive technologies

Many infertile couples feel vulnerable after failed treatment cycles and find insensitive remarks or inappropriate support distressing. They fear that the stress of failed treatment cycles may affect their marriage and lead to marriage breakdown. This study explored the strategies a sample of infertile couples used to manage social interactions after unsuccessful treatment with assisted reproductive technologies. A descriptive qualitative study was conducted with 34 participants including nine infertile couples, nine infertile women and two infertile men with primary infertility, two relatives, and three fertility clinic staff. The participants were selected through purposive sampling at an infertility centre in Iran, between 2016 and 2017. Data were collected using semi-structured face-to-face interviews and analysed by qualitative content analysis approach. Participants found some social interactions after failed assisted reproductive treatment cycles to be distressing and painful. They described tolerating painful emotions which cause them sadness and sorrow as well as feeling embarrassed. As a result, they found they needed to maintain their adopting concealment strategies with their families through not permitting speculation, selective disclosure, not giving details and hiding the truth. This study showed that social interactions following failed assisted reproductive cycles can be upsetting for infertile couples. Couples use different strategies to manage potentially distressing social interactions. Healthcare providers and psychologists may provide a space for safe social interactions in order to help couples to use appropriate strategies in these circumstances

Infertile couples' perceived needs after unsuccessful fertility treatment: A qualitative study

Introduction: Infertility is a major medical issue. Investigations and treatment of infertility are the beginning of a complex, time-consuming and stressful process for couples that may fail well. The present study explored the needs of infertile couples following treatment failure with Assisted Reproductive Technologies (ARTs). Methods: A descriptive qualitative study was conducted in an Iranian infertility center, in the Northeast of the country between April 2016 and June 2017. The researchers recruited 29 individuals including 9 couples, 9 women and two men with primary infertility through purposive sampling. The data were collected using semi-structured interviews and analyzed iteratively, using conventional content analysis with MAXQDA software. Results: The main concepts obtained from the data were classified into one theme titled: ""The need for support"" and four main categories along with their subcategories, and included the need for psychological support, the need for more useful information, the need for social support and the need to access to supplementary services. Conclusion: The findings show that following treatment failure, the infertile patients’ expressed needs and preferences were not met. Identifying and meeting their needs may help the infertile couples to deal with ARTs failure and to reach a decision about future treatment

Traditional Cardiovascular Risk Factors as Predictors of Cardiovascular Events in the U.S. Astronaut Corps

Risk prediction equations from the Framingham Heart Study are commonly used to predict the absolute risk of myocardial infarction (MI) and coronary heart disease (CHD) related death. Predicting CHD-related events in the U.S. astronaut corps presents a monumental challenge, both because astronauts tend to live healthier lifestyles and because of the unique cardiovascular stressors associated with being trained for and participating in space flight. Traditional risk factors may not hold enough predictive power to provide a useful indicator of CHD risk in this unique population. It is important to be able to identify individuals who are at higher risk for CHD-related events so that appropriate preventive care can be provided. This is of special importance when planning long duration missions since the ability to provide advanced cardiac care and perform medical evacuation is limited. The medical regimen of the astronauts follows a strict set of clinical practice guidelines in an effort to ensure the best care. The purpose of this study was to evaluate the utility of the Framingham risk score (FRS), low-density lipoprotein (LDL) and high-density lipoprotein levels, blood pressure, and resting pulse as predictors of CHD-related death and MI in the astronaut corps, using Cox regression. Of these factors, only two, LDL and pulse at selection, were predictive of CHD events (HR(95% CI)=1.12 (1.00-1.25) and HR(95% CI)=1.70 (1.05-2.75) for every 5-unit increase in LDL and pulse, respectively). Since traditional CHD risk factors may lack the specificity to predict such outcomes in astronauts, the development of a new predictive model, using additional measures such as electron-beam computed tomography and carotid intima-media thickness ultrasound, is planned for the future

A Novel Technique for the In Vivo Imaging of Autoimmune Diabetes Development in the Pancreas by Two-Photon Microscopy

Type 1 diabetes (T1D) is characterized by the immune-mediated destruction of beta cells in the pancreas. Little is known about the in vivo dynamic interactions between T cells and beta cells or the kinetic behavior of other immune cell subsets in the pancreatic islets. Utilizing multiphoton microscopy we have designed a technique that allows for the real-time visualization of diabetogenic T cells and dendritic cells in pancreatic islets in a live animal, including their interplay with beta cells and the vasculature. Using a custom designed stage, the pancreas was surgically exposed under live conditions so that imaging of islets under intact blood pressure and oxygen supply became possible. We demonstrate here that this approach allows for the tracking of diabetogenic leukocytes as well as vascularization phenotype of islets and accumulation of dendritic cells in islets during diabetes pathogenesis. This technique should be useful in mapping crucial kinetic events in T1D pathogenesis and in testing the impact of immune based interventions on T cell migration, extravasation and islet destruction

Identification of a novel KCNQ1 frameshift mutation and review of the literature among iranian long QT families

Background: Long QT syndrome (LQTS) is characterized by the prolongation of QT interval, which results in syncope and sudden cardiac death in young people. KCNQ1 is the most common gene responsible for this syndrome. Methods: Molecular investigation was performed by DNA Sanger sequencing in Iranian families with a history of syncope. In silico examinations were performed for predicting the pathogenicity of the novel variant. Results: A novel homozygous KCNQ1 frameshift mutation, c.14261429delATGC (M476Pfs*4), was identified, and then the current literatures of five patients were reviewed regarding the LQTS. Conclusion: The novel frameshift mutation has been reported for the first time among the Iranian population. Our finding along with the case series study of LQTS patients illustrates the importance of genetic and case series in precise detection of the frequency of LQTS carrierscarriers. © 2019, Pasteur Institute of Iran. All rights reserved

Novel frameshift mutation in the KCNQ1 gene responsible for jervell and lange-nielsen syndrome

Objective(s): Jervell and Lange�Nielsen syndrome is an autosomal recessive disorder caused by mutations in KCNQ1 or KCNE1 genes. The disease is characterized by sensorineural hearing loss and long QT syndrome. Materials and Methods Here we present a 3.5-year-old female patient, an offspring of consanguineous marriage, who had a history of recurrent syncope and congenital sensorineural deafness. The patient and the family members were screened for mutations in KCNQ1 gene by linkage analysis and DNA sequencing. Results: DNA sequencing showed a c.15321534delG (p. A512Pfs*81) mutation in the KCNQ1 gene in homozygous form. The results of short tandem repeat (STR) markers showed that the disease in the family is linked to the KCNQ1 gene. The mutation was confirmed in the parents in heterozygous form. Conclusion: This is the first report of this variant in KCNQ1 gene in an Iranian family. The data of this study could be used for early diagnosis of the condition in the family and genetic counseling. © 2018, Mashhad University of Medical Sciences. All rights reserved

Novel frameshift mutation in the KCNQ1 gene responsible for jervell and lange-nielsen syndrome

Objective(s): Jervell and Lange�Nielsen syndrome is an autosomal recessive disorder caused by mutations in KCNQ1 or KCNE1 genes. The disease is characterized by sensorineural hearing loss and long QT syndrome. Materials and Methods Here we present a 3.5-year-old female patient, an offspring of consanguineous marriage, who had a history of recurrent syncope and congenital sensorineural deafness. The patient and the family members were screened for mutations in KCNQ1 gene by linkage analysis and DNA sequencing. Results: DNA sequencing showed a c.15321534delG (p. A512Pfs*81) mutation in the KCNQ1 gene in homozygous form. The results of short tandem repeat (STR) markers showed that the disease in the family is linked to the KCNQ1 gene. The mutation was confirmed in the parents in heterozygous form. Conclusion: This is the first report of this variant in KCNQ1 gene in an Iranian family. The data of this study could be used for early diagnosis of the condition in the family and genetic counseling. © 2018, Mashhad University of Medical Sciences. All rights reserved