Outlier Detection Based on Discrete Wavelet Transform with Application to Saudi Stock Market Closed Price Series

RASHEDI, Khudhayr A.,ISMAIL, Mohd T.,WADI, S. Al,SERROUKH, Abdeslam Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

This study investigates the problem of outlier detection based on discrete wavelet transform in the context of time series data where the identification and treatment of outliers constitute an important component. An outlier is defined as a data point that deviates so much from the rest of observations within a data sample. In this work we focus on the application of the traditional method suggested by Tukey (1977) for detecting outliers in the closed price series of the Saudi Arabia stock market (Tadawul) between Oct. 2011 and Dec. 2019. The method is applied to the details obtained from the MODWT (Maximal-Overlap Discrete Wavelet Transform) of the original series. The result show that the suggested methodology was successful in detecting all of the outliers in the series. The findings of this study suggest that we can model and forecast the volatility of returns from the reconstructed series without outliers using GARCH models. The estimated GARCH volatility model was compared to other asymmetric GARCH models using standard forecast error metrics. It is found that the performance of the standard GARCH model were as good as that of the gjrGARCH model over the out-of-sample forecasts for returns among other GARCH specifications.

Interactions between host plant, Aphis fabae, and its natural enemies, Orius albidipennis and Lysiphlebus fabarum in a tritrophic system

Ahmad Rashedi,Ali Rajabpour,Arash Rasekh,Nooshin Zandi-Sohani 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

The interactions between two natural enemies (NEs) were studied in a tritrophic system to evaluate the efficacy of simultaneous releases of a parasitoid, Lysiphlebus fabarum Marshal (Hymenoptera: Braconidae) and a predator, Orius albidipennis Reuter (Heteroptera: Anthocoridae) against Aphis fabae Scopoli (Homoptera: Aphididae). Three experiments were performed to evaluate the prey preference of a predator to parasitized versus unparasitized aphid hosts; to investigate the emission of volatile synomones by the host plant, Vicia fabae, and to determine its behavioral effect on the NEs; and to determine behavioral effect of volatile infochemicals between NEs. Results showed that the female predatory bug did not show significant preference between parasitized and unparasitized aphids, but the male bug had significant preference for parasitized mummies. Olfactometry trials documented that both NEs were significantly attracted to volatile cues released by the host plant infested with the aphid. Each of the NEs avoided odors which indicated the presence of another intraguild competitor. Therefore, simultaneously releases of the NEs are not recommended.

Aortic Stenosis: Changing Disease Concepts

Nina Rashedi,Catherine M. Otto 한국심초음파학회 2015 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.23 No.2

Aortic stenosis (AS) occurs in almost 10% of adults over age 80 years with a mortality about 50% at 2 years unless outflowobstruction is relieved by aortic valve replacement (AVR). Development of AS is associated with anatomic, clinical and geneticrisk factors including a bicuspid valve in 50%; clinical factors that include older age, hypertension, smoking, diabetes andelevated serum lipoprotein(a) [Lp(a)] levels; and genetic factors such as a polymorphism in the Lp(a) locus. Early stages of AS arecharacterized by focal areas of leaflet thickening and calcification. The rate of hemodynamic progression is variable but eventualsevere AS is inevitable once even mild valve obstruction is present. There is no specific medical therapy to prevent leaflet calcification. Basic principles of medical therapy for asymptomatic AS are patient education, periodic echocardiographic and clinicalmonitoring, standard cardiac risk factor evaluation and modification and treatment of hypertension or other comorbid conditions. When severe AS is present, a careful evaluation for symptoms is needed, often with an exercise test to document symptom statusand cardiac reserve. In symptomatic patients with severe AS, AVR improves survival and relieves symptoms. In asymptomaticpatients with severe AS, AVR also is appropriate if ejection fraction is < 50%, disease progression is rapid or AS is very severe(aortic velocity > 5 m/s). The choice of surgical or transcatheter AVR depends on the estimated surgical risk plus other factorssuch as frailty, other organ system disease and procedural specific impediments.

Spatiotemporal Gait Parameters and Gait Asymmetry in Patients With Lumbar Disc Herniation, Treated With Microdiscectomy: A Prospective, Observational Study

Masoud Amir Rashedi Bonab,Suleyman Sener,Tugba Kuru Colak,Mahsa Amirrashedi,Ipek Yeldan,Deniz Konya,Zafer Orkun Toktas 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: The aim of this study was to emphasize on the interaction of spatial and temporal gait parameters and analyse the gait asymmetry in the patients with lumbar disc herniation (LDH) before and after microdiscectomy. Methods: This was a prospective, observational study conducted on 59 cases of LDH planned for lumbar microdiscectomy, and healthy control group with 54 participants for analysis was performed prior to surgery and 15 days after surgery. The spatiotemporal gait parameters were measured using a “Win-Track” gait analysis platform system. All the participants walked barefoot for 10 times with their normal walking speed in the same day. The 3 flawless walking data were recorded and the arithmetic means were computed. The gait symmetry index was used to calculate the walking asymmetry. The pain intensity of the patients was recorded shortly before performing the analysis by a visual analogue scale. Results: In the postoperative assessment LDH patients had significantly shorter temporal parameters, longer spatial parameters, faster walking speed, and more cadence than the preoperative assessment (p < 0.05). There were improvements in the asymmetry values of the postoperative gait parameters compared to the preoperative values, but these differences were not significant (p > 0.05). In addition, there was a significant difference in all parameters in terms of gait asymmetry between the postoperative assessment and the healthy controls (p < 0.05). Conclusion: These results can guide the patient-specific evaluating and implementation of gait rehabilitation programs, and design protocols before or after surgery in the LDH patients.

Spoken and Written Narrative in Persian-Speaking Students Who Received Cochlear Implant and/or Hearing Aid

Peyman Zamani,Zahra Soleymani,Vahid Rashedi,Farhad Farahani,Gohar Lotfi,Mohammad Rezaei 대한이비인후과학회 2018 Clinical and Experimental Otorhinolaryngology Vol.11 No.4

Objectives. To compare narrative skills between fourth and fifth grades of Persian-speaking students with hearing impairments and typical hearing students of the same grade and also to evaluate the effects of group, sex, hearing age, and educational grade of the students on their spoken/written narrative performance. Methods. The subjects were 174 students aged 10–13 years, 54 of whom wore cochlear implants, 60 suffered from moderate to severe hearing losses and wore hearing aids, with the remaining 60 students being typical hearing in terms of the sense of hearing. The micro- and macrostructure components of spoken and written narrative were elicited from a pictorial story (The Playful Little Elephant) and then scored by raters. Results. Compared to the typical hearing, the students with hearing impairments had significantly lower scores in all of the microstructure components of narratives. However, the findings showed no significant difference among different groups in macrostructure components of narratives. It was also revealed that the students had equal performance in spoken and written narrative. Finally, factor analysis manifested that group, sex, hearing age, and educational level of children might alter the outcome measures in various interactions. Conclusion. Although cochlear implantation was more effective than hearing aid on spoken and written narrative skills, the Persian-speaking students with hearing impairments were seen to need additional trainings on microstructure components of spoken/written narrative.

False-Positive Mycobacterium tuberculosis Detection: Ways to Prevent Cross- Contamination

( Mohammad Asgharzadeh ),( Mahdi Asghari Ozma ),( Jalil Rashedi ),( Behroz Mahdavi Poor ),( Vahid Agharzadeh ),( Ali Vegari ),( Behrooz Shokouhi ),( Khudaverdi Ganbarov ),( Nima Najafi Ghalehlou ),( H 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.3

The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on falsepositive cultures of M. tuberculosis . Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, falsepositive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.

Effects of Phosphate and Two-Stage Sous-Vide Cooking on Textural Properties of the Beef Semitendinosus

Nurul Nazirah Ruslan,John Yew Huat Tang,Nurul Huda,Mohammad Rashedi Ismail-Fitry,Ismail Ishamri 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.3

Comparing the effects of sodium tripolyphosphate (STPP) concentrations of 0.2% and 0.4% on beef semitendinosus is the objective of the current investigation. The samples were cooked at varied temperatures (45+60℃ and 45+70℃) and times (1.5+1.5 h and 3+3 h) using staged cooking. The colour properties, cooking loss, water retention, shear force, water-holding capacity, sarcoplasmic, and myofibrillar solubility, and total collagen were investigated. The cooking time and temperature affected the water-holding capacity, cooking loss, CIE L*, CIE a*, CIE b*, myofibrillar, and sarcoplasmic solubility, with lower temperature and short time having the lower detrimental effect. However, the significant effect can be intensified after the addition of STPP with higher water-holding capacity and tender meat obtained with 0.4% phosphate concentration at any cooking conditions. The STPP lowered the collagen content and increased the protein solubility of myofibrillar and sarcoplasmic, which this degradation is used as a good indicator of tenderness.