Multivariate Multiscale Analysis of Neural Spike Trains

This dissertation introduces new methodologies for the analysis of neural spike trains. Biological properties of the nervous system, and how they are reflected in neural data, can motivate specific analytic tools. Some of these biological aspects motivate multiscale frameworks, which allow for simultaneous modelling of the local and global behaviour of neurons. Chapter 1 provides the preliminary background on the biology of the nervous system and details the concept of information and randomness in the analysis of the neural spike trains. It also provides the reader with a thorough literature review on the current statistical models in the analysis of neural spike trains. The material presented in the next six chapters (2-7) have been the focus of three papers, which have either already been published or are being prepared for publication. It is demonstrated in Chapters 2 and 3 that the multiscale complexity penalized likelihood method, introduced in Kolaczyk and Nowak (2004), is a powerful model in the simultaneous modelling of spike trains with biological properties from different time scales. To detect the periodic spiking activities of neurons, two periodic models from the literature, Bickel et al. (2007, 2008); Shao and Li (2011), were combined and modified in a multiscale penalized likelihood model. The contributions of these chapters are (1) employinh a powerful visualization tool, inter-spike interval (ISI) plot, (2) combining the multiscale method of Kolaczyk and Nowak (2004) with the periodic models ofBickel et al. (2007, 2008) and Shao and Li (2011), to introduce the so-called additive and multiplicative models for the intensity function of neural spike trains and introducing a cross-validation scheme to estimate their tuning parameters, (3) providing the numerical bootstrap confidence bands for the multiscale estimate of the intensity function, and (4) studying the effect of time-scale on the statistical properties of spike counts. Motivated by neural integration phenomena, as well as the adjustments for the neural refractory period, Chapters 4 and 5 study the Skellam process and introduce the Skellam Process with Resetting (SPR). Introducing SPR and its application in the analysis of neural spike trains is one of the major contributions of this dissertation. This stochastic process is biologically plausible, and unlike the Poisson process, it does not suffer from limited dependency structure. It also has multivariate generalizations for the simultaneous analysis of multiple spike trains. A computationally efficient recursive algorithm for the estimation of the parameters of SPR is introduced in Chapter 5. Except for the literature review at the beginning of Chapter 4, the rest of the material within these two chapters is original. The specific contributions of Chapters 4 and 5 are (1) introducing the Skellam Process with Resetting as a statistical tool to analyze neural spike trains and studying its properties, including all theorems and lemmas provided in Chapter 4, (2) the two fairly standard definitions of the Skellam process (homogeneous and inhomogeneous) and the proof of their equivalency, (3) deriving the likelihood function based on the observable data (spike trains) and developing a computationally efficient recursive algorithm for parameter estimation, and (4) studying the effect of time scales on the SPR model. The challenging problem of multivariate analysis of the neural spike trains is addressed in Chapter 6. As far as we know, the multivariate models which are available in the literature suffer from limited dependency structures. In particular, modelling negative correlation among spike trains is a challenging problem. To address this issue, the multivariate Skellam distribution, as well as the multivariate Skellam process, which both have flexible dependency structures, are developed. Chapter 5 also introduces a multivariate version of Skellam Process with Resetting (MSPR), and a so-called profile-moment likelihood estimation of its parameters. This chapter generalizes the results of Chapter 4 and 5, and therefore, except for the brief literature review provided at the beginning of the chapter, the remainder of the material is original work. In particular, the contributions of this chapter are (1) introducing multivariate Skellam distribution, (2) introducing two definitions of the Multivariate Skellam process in both homogeneous and inhomogeneous cases and proving their equivalence, (3) introducing Multivariate Skellam Process with Resetting (MSPR) to simultaneously model spike trains from an ensemble of neurons, and (4) utilizing the so-called profile-moment likelihood method to compute estimates of the parameters of MSPR. The discussion of the developed methodologies as well as the ``next steps'' are outlined in Chapter 7

Examining the quality of work life: empirical testing indicators in the public organisation

Purpose: The present study aimed to identify employees’ quality of work life indicators in public organisations and provide necessary context to improve system accountability and employees’ needs in organisations. Research methodology: To identify quality of work life indicators, authors studied theoretical research basics entirely and by considering elites’ ideas, identified main indicators by a descriptive – survey technique. Result: Based on research findings, 15 constituents were identified as work life quality indicators. Research results indicate undesired quality of work life among employees at public organisations. Of identified constituents, Safe and healthy working conditions and organisational conflict are the most important and job satisfaction and Pay/benefits are the lowest important factors. Limitations: The results only extend the understanding of the role of quality of work life in organisational effectiveness and have implications for human resource managers that may not be applicable for other positions. Contribution: The study results help organisations identify the elements that affect the QWL and help them plan to increase organisational effectiveness by increasing employee satisfaction and motivation

Effect of Cement Dust on Pulmonary Functions of Cement Workers

Background: Among cement dust, quartz particles are the most harmful and cause pulmonary fibrosis, which is pathologically among the severe and malignant pneumoconioses. Therefore, by measuring the dust and examining the status of lung functions among workers, we can assess the effects of inhaling cement dust. We aimed to assess the effect of cement dust on pulmonary functions among cement workers during 1999-2000 in Khash, Sistan and Baluchestan Province, Iran. Material and Methods: The total and inhalation dust of the working environment of different units in this industry was measured by individual sampling pump and silicon by weight method and after correcting the volumes, mg/m3 of dust was calculated.  Results: The total dust in different environments was 6.8-95 mg/m3 and the inhaled dust was 2.5-23 mg/m3. Due to the percentage of free silica associated with dust, these values are several times the standard values in the workplace.  The mean values of respiratory functions (FEV1, FVC, VC) in all cases were lower (P-value<0.005) than the mean values in the control group. The difference in the mean FEF25-75 values between the two groups was not significant (P-value>0.5). Although in the case group (all types of workers) the percentage of people with cough was more than the control group, the difference was not statistically significant (P<0.05). With respect to having sputum in the morning and during the day and night and the type of sputum (green and thick, thin, and no sputum), the case group experienced higher rates of sputum and respiratory symptoms. Conclusion: The working environments of cement factories, contrary to what is stated in the toxicology textbooks, requires more attention of health experts and industry managers. Examinations and periodic dust control measures and hiring an occupational health expert is necessary to maintain the health of workers in these environments

Investigation of caspase-1 activity and interleukin-1β production in murine macrophage cell lines infected with Leishmania major

AbstractObjectiveTo investigate the caspase-1 dependent inflammatory pathway activity and interleukin-1β (IL-1β) secretion in murine macrophage cell lines J774G8 infected with Leishmania major (L. major) using caspase-1 activity assay and ELISA.MethodsNovy-MacNeal-Nicolle biphasic medium was applied to produce promastigote form of L. major. Metacyclic promastigotes in the stationary phase were applied to infect macrophage. Caspase-1 activity and IL-1β secretion were assessed by the CPP32/caspase-1 fluorometric protease assay and ELISA IL-1β kits, respectively, with time intervals of 6, 18 and 30 h.ResultsOur study showed an increase in caspase-1 activity and IL-1β secretion in infected samples compared to non-infected macrophages. The highest increase in IL-1β production was observed after 6 h of infection.ConclusionsThese results arise that the activation of inflammasome pathway could be one of the innate immunity pathways against L. major

Improvement of post-thawed sperm quality in broiler breeder roosters by ellagic acid-loaded liposomes

P. 440–446Liposomes could improve the delivery of substances to sperm. This study was conducted to investigate the effect of the antioxidant ellagic acid and ellagic acid-loaded liposomes on post-thawed sperm quality in broiler breeder roosters. Semen was diluted in Beltsville extender containing ellagic acid or ellagic acid-loaded liposomes (ellagic acid at 0 (control), 0.5, 1, and 2 mM) and cryopreserved. Sperm quality was evaluated post-thawing: motility characteristics (Computer-Assisted Semen Analysis), membrane functionality (HOS test), abnormal morphology, mitochondrial activity (Rhodamine 123), apoptotic status (Annexin V/Propidium iodide), malondialdehyde, and antioxidant activities (glutathione peroxidase (GPx), superoxide dismutase (SOD), and total antioxidant capacity (TAC)). The results showed that 1 mM ellagic acid-loaded liposomes improved total motility, membrane functionality, and viability comparing to 0.5 and 2 mM ellagic acid, 2 mM ellagic acid-loaded liposomes, and control group. Mitochondrial activity was significantly higher for 1 mM ellagic acid-loaded liposomes compared to the rest of the treatments, except 1 mM ellagic acid. Ellagic acid at 1 mM in both forms significantly increased GPx and TAC after freeze-thawing (no significant variation for SOD), and also yielded the lower proportion of apoptotic and dead cells. In conclusion, ellagic acid improved post-thawed sperm quality in broiler breeder roosters. The use of liposomes could further enhance the effects of ellagic acid.S

Synthesis and characterization of a novel chemically designed (Globo)3–DTPA–KLH antigen

In recent years, many experiments have been conducted for the production and evaluation of anticancer glycoconjugated vaccines in developed countries and many achievements have been accomplished with Globo H derivatives. In the current experiment, a new chemically designed triplicate version of (Globo H)3–diethylenetriamine pentaacetic acid (DTPA)–KLH antigen was synthesized and characterized. Immunization with (Globo H)3-DTPA-KLH, a hexasaccharide that is a member of a family of antigenic carbohydrates that are highly expressed in various types of cancers conjugated with DTPA and KLH protein, induced a high level of antibody titer along with an elevated level of IL-4 in mice. Treatment of tumors with the collected sera from immunized mice decreased the tumor size in nude mice as well. None of the immunized mice illustrated any sign of tumor growth after injection of MCF-7 cells compared to the control animals. These findings, based on the newly presented structure of the Globo H antigen, lend exciting and promising evidence for clinical advancement in the development of a therapeutic vaccine in the future

Capacity building for priority setting in Farrokhshahr population

زمینه و هدف: تعیین‌ اولویت‌های پژوهشی فرآیندی‌ مهم‌ در مدیریت‌ پژوهش‌ها در تمام حوزه ها بخصوص حوزه سلامت‌ کشورها بشمار می رود که‌ اهمیت‌ آن‌ بویژه‌در زمان‌ تخصیص‌ منابع‌ محدود مالی‌ و انسانی‌ دو چندان‌ می شود. فرآیند تعیین‌ اولویت‌ها به‌ تمامی‌ کشورها در زمینه‌ طرح‌ ریزی‌ برنامه‌های‌ پژوهش‌ در حوزه‌ سلامت‌ و بسیج‌ و تخصیص‌ منابع‌ پژوهشی‌ و همچنین‌ تقویت ‌ظرفیت‌ پژوهشی‌ بومی‌ خود کمک‌ خواهد کرد. گروههای‌ ذینفعی‌ که‌ باید در فرآیند تعیین‌ اولویت‌ها شرکت‌ داده‌ شوند علاوه‌ برپژوهشگران‌ شامل‌ بهره‌ گیرندگان‌ بالقوه‌ و مردمی‌ می‌باشند که‌ از نتایج‌ پژوهش‌ تأثیر خواهند پذیرفت‌. در این مطالعه توانمند سازی مردم در تعیین اولویت های مشکلات مردم فرخشهر در استان چهار محال و بختیاری به صورت مشارکتی مورد بررسی قرار گرفته است. روش بررسی: این‌ پروژه‌ یک‌ تحقیق‌ مشارکتی است که‌ در آن‌ مشکلات‌ شناسایی‌ شده‌ با روش‌ ارزیابی‌ سریع (Rapid appraisal) در شهر فرخشهر، استان‌ چهارمحال‌ و بختیاری‌ در سال‌ 83 توسط تیم توسعه فرخشهر با مشارکت معاونت پژوهشی دانشگاه علوم پزشکی شهرکرد مورد اولویت‌ بندی‌ قرار گرفتند پس‌ از طبقه‌ بندی‌ اطلاعات‌ بدست‌ آمده‌ از نیازسنجی‌ با در نظر گرفتن‌ عوامل‌ محیطی‌، اقتصادی‌، اجتماعی‌، ساختار نهادها و مؤسسات‌ منطقه‌ و همچنین‌ شناسایی‌ عوامل‌ کند کننده‌ و مانع‌ شونده‌ و شرایط زندگی‌ و معیشتی‌ گروههای‌ مختلف‌ مردم و تعیین‌ ارتباط آن‌ با عوامل‌ فوق‌ الذکر مشکلات‌ اولویت‌ بندی‌ و تجزیه‌ و تحلیل‌ شد. در فرآیند مشارکت جامعه، پرسنل ناظر و اجرائی ابتدا هدف از تعیین اولویت هارا برای عموم شرکت کنندگان شرح دادند و تمامی نکات مبهم را روشن ساختند فرآیند مشارکت بصورت تبادل فعال مشارکت یا مشاوره که از پیشنهادات و نظرات مردم در برنامه ریزی و تصمیم گیری استفاده شود دنبال شد و در آخر تصمیم گیری در مورد تعیین اولویت ها به مردم واگذار شد کل فرآیند با مشارکت فعال اعضای تیم توسعه فرخشهر و با نظارت محققین دانشگاه که به عنوان ناظر شرکت داشتند انجام گردید. ابزارهای اولویت بندی در گروههای ذینفع شامل: ماتریس دو بعدی، دیاگرام اولویت ها، جدول تجزیه و تحلیل مشکلات، دیاگرام ون گروهها دینفع، ماتریس اختلاف و همکاری بین گروههای ذینفع بود. یافته ها: در این‌ مطالعه‌ 40 مشکل‌ مردم‌ فرخشهر شناسایی‌ و در 9 گروه طبقه‌ بندی‌ گردید: مشکلات‌ سالمندان‌، فرهنگی‌ هنری‌، عمرانی‌، ورزشی‌، زنان‌، بهداشت‌ روان‌، جوانان‌، امنیت‌ اجتماعی‌ و مشکلات‌ اشتغال طی فرآیند فوق 20 مشکل به عنوان اولویت های اول تا بیستم تعیین گردید. نهایتاَ با تجزیه و تحلیل داده های بدست آمده از ابزار های اولویت بندی، درک صحیحی از مشکلات حائز اولویت، فرصت ها، اقدامات صورت گرفته، راه حل ها و منابع بالقوه و بالفعل پیش رو برای حل مشکلات حاصل شد

The survey statistical and biological of sturgeon in the southern Caspian Sea (Mazandaran waters)

This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9% , respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only