Category: Nevin Manimala

Cogn Sci. 2021 Jun;45(6):e13009. doi: 10.1111/cogs.13009.

ABSTRACT

The investigation of visual categorization has recently been aided by the introduction of deep convolutional neural networks (CNNs), which achieve unprecedented accuracy in picture classification after extensive training. Even if the architecture of CNNs is inspired by the organization of the visual brain, the similarity between CNN and human visual processing remains unclear. Here, we investigated this issue by engaging humans and CNNs in a two-class visual categorization task. To this end, pictures containing animals or vehicles were modified to contain only low/high spatial frequency (HSF) information, or were scrambled in the phase of the spatial frequency spectrum. For all types of degradation, accuracy increased as degradation was reduced for both humans and CNNs; however, the thresholds for accurate categorization varied between humans and CNNs. More remarkable differences were observed for HSF information compared to the other two types of degradation, both in terms of overall accuracy and image-level agreement between humans and CNNs. The difficulty with which the CNNs were shown to categorize high-passed natural scenes was reduced by picture whitening, a procedure which is inspired by how visual systems process natural images. The results are discussed concerning the adaptation to regularities in the visual environment (scene statistics); if the visual characteristics of the environment are not learned by CNNs, their visual categorization may depend only on a subset of the visual information on which humans rely, for example, on low spatial frequency information.

PMID:34170027 | DOI:10.1111/cogs.13009

Turk Neurosurg. 2021 Mar 21. doi: 10.5137/1019-5149.JTN.33347-20.2. Online ahead of print.

ABSTRACT

AIM: To elucidate the association of MTHFR, MTRR and RAD54L gene variations in Turkish meningioma cohort.

MATERIAL AND METHODS: DNAs were isolated from 87 retrospective meningioma tumor samples. MTHFR, MTRR and RAD54L genes hot spot regions were amplified with specific primers by polymerase chain reaction (PCR) and next generation sequencing (NGS) was performed. All detected variations and single nucleotide polymorphisms were listed and compared with healthy control frequencies in different genomic databases. Histopathological characteristics of tumors and genomic variations were compared. The Pearson’s chi-square test was used to detect statistical differences of SNPs and correlation analysis was performed.

RESULTS: rs1801131, rs1801133 and rs4846051 on MTHFR gene, rs1801394 on MTRR gene, rs1048771 on RAD54L gene frequencies found to be significantly altered in overall cohort of 87 meningioma patients. The frequency of rs18011031 is 0.09 in meningioma which is significantly correlated with WHO grades of tumors (p=0.038). The frequency of rs18011033 is 0.29, and significantly correlated with WHO grades of tumors (p=0.045). The frequency of rs4846051 is 0.18 in meningioma cohort which is significantly correlated with WHO grades of tumors (p=0.023) and also with low Ki67 proliferation index (p=0.00455). The frequency of rs1801394 is 0.15 and significantly associated with high Ki67 proliferation index on meningioma tumors (p=0.0144). The frequency of rs1048771 is 0.09 in meningioma cohort and it is significantly associated with non-necrotic histopathological form of tumor (p=0.05).

CONCLUSION: We reported significant association between genetic alterations of folate metabolism (MTHFR, MTRR) and DNA repair mechanism (RAD54L) genes with the histopathological characteristics of the meningioma tumors. Five significant SNPs on these genes and four significant correlations of SNPs with histopathological characteristics were identified. Our study is a preliminary promising study to establish the genetics marker analysis for meningioma diagnosis and prognosis for folate metabolism and DNA repair associated genes in Turkish cohort.

PMID:34169999 | DOI:10.5137/1019-5149.JTN.33347-20.2

Turk Neurosurg. 2021 Apr 13. doi: 10.5137/1019-5149.JTN.33760-21.3. Online ahead of print.

ABSTRACT

AIM: This study aimed to compare the morphometric characteristics of the foramen ovale (FO) and rotundum (FR) and their localization in the middle cranial fossa in head and neck computed tomography images in patients with trigeminal neuralgia (TN) and asymptomatic individuals.

MATERIAL AND METHODS: FO and FR length, width and area parameters were examined in 158 asymptomatic individuals and 19 patients with TN. Their location in the middle cranial fossa was determined according to the sagittal (y) axis passing through the middle of the dorsum sella and connecting the foremost point and the rearmost point of the skull, and the transverse (x) axis passing through the middle of this axis. In comparisons with asymptomatic individuals, data on the painful side of patients with trigeminal neuralgia were used.

RESULTS: The mean width of the FO and its distance from the transverse axis were determined 3.36±0.79 mm and 1.44±0.39 mm in asymptomatic individuals, 2.88±0.83 mm and 1.23±0.45 in TN patients, respectively. These FO parameters were statistically significantly smaller in patients with TN. In asymptomatic individuals, while the mean width of the FR was determined to be 2.05±0.48 mm, the mean length was 2.14±0.47 mm, and its distance to the transverse axis and sagittal axis was found to be 2.65±0.35 mm and 1.96±0.25 mm, respectively. In patients with TN, while the mean width of the FR was revealed to be 1.77±0.46 mm, the mean length was 1.78±0.42 mm, and its distance to the transverse axis and sagittal axis was found to be 2.33±0.40 mm and 1.87±0.16 mm, respectively. These FR parameters were statistically significantly smaller in patients with TN.

CONCLUSION: The fact that the dimensions of the FO and FR and their distances to the sagittal and transverse axes were statistically significantly smaller in patients with TN suggested that it may be one of the causes of TN.

PMID:34170000 | DOI:10.5137/1019-5149.JTN.33760-21.3

Clin Cardiol. 2021 Jun 25. doi: 10.1002/clc.23678. Online ahead of print.

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac rhythm disturbance and leads to morbidity and mortality. Peripheral artery disease (PAD) is associated with atherosclerotic risk factors and always classified as a vascular disease and deemed to be a bad complication of AF. In patients with AF, the risk and prognostic value of PAD have not been estimated comprehensively.

HYPOTHESIS: PAD is associated with all-cause mortality, cardiovascular (CV) mortality, and other outcomes in patients with AF.

METHODS: We searched PubMed, Embase, and Cochrane Library databases for prospective studies published before April 2021 that provided outcomes data on PAD in confirmed patients with AF. Heterogeneity was estimated using the I² statistic. The fixed-effects model was used for low to moderate heterogeneity studies, and the random-effects model was used for high heterogeneity studies.

RESULTS: Eight prospective studies (Newcastle-Ottawa score range, 7-8) with 39 654 patients were enrolled. We found a significant association between PAD and all-cause mortality (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.25-1.62; p < .001), CV mortality (HR, 1.64; 95% CI, 1.32-2.05; p < .001) and MACE (HR, 1.75; 95% CI, 1.38-2.22; p < .001) in patients with AF. No significant relationship was found in major bleeding (HR, 1.22; 95% CI, 0.95-1.57; p = 0.118), myocardial infarction (MI) (HR, 2.07; 95% CI, 1.17-3.67; p = .038), and stroke (HR, 1.14; 95% CI, 0.87-1.50, p = 0.351).

CONCLUSIONS: PAD is associated with an increased risk of all-cause mortality, CV mortality, and MACE in patients with AF. However, no significant association was found with major bleeding, MI, and stroke.

PMID:34170015 | DOI:10.1002/clc.23678

Biomed Instrum Technol. 2020 Jun 1;54(s1):64-72. doi: 10.2345/0899-8205-54.s3.64.

ABSTRACT

The validation of a radiation sterilization dose involves an initial sterilization dose determination as well as maintenance of that sterilization dose. The procedures for maintenance of the sterilization dose typically include the periodic use of two types of tests: bioburden and dose audits. The details for the procedures are outlined in the ISO radiation sterilization standards. These documents also provide guidelines for recommended actions in response to the results of the two tests. The results for the dose audit are based on the number of positive tests of sterility (TOS) for products that have been irradiated at a verification or experimental dose. When the dose audit yields TOS positives, it is often thought that they indicate a sterilization failure and nonsterile product. The belief that any TOS positive is a failure is an incorrect assumption because of the statistical basis used for the determination of the sterilization dose. This article will outline the truth of what dose audit TOS positives mean in terms of the sterility assurance of product, as well as the consequences of TOS positives.

PMID:34169976 | DOI:10.2345/0899-8205-54.s3.64

Turk Neurosurg. 2021 Jan 20. doi: 10.5137/1019-5149.JTN.32701-20.3. Online ahead of print.

ABSTRACT

AIM: Foramina transversaria (FT) are located on the transverse process of cervical vertebrae. These foramina are known to exhibit variations with regard to shape, size and may even absent, incomplete or duplicated. The aim of this study was to investigate the variations in number, shape, size of foramina transversaria of the human cervical vertebrae and their clinical importance Material and Methods: 200 dry cervical vertebrae (C3-C7) of 40 spines were studied for the presence of variations in number, size and shape of the FT. The foramina were further classified according to their shape depending upon the direction of their main diameter Results: Accessory foramina was found in 40 cervical vertebrae. Bilateral accessory foramen was slightly more common than a unilateral one. Occurrence of accessory foramen followed a particular pattern. Incidence increased in descending order of cervical vertebrae and most commonly found in C7. On the right side, the mean of antero-posterior and transverse diameter was 4.96±1.08 mm and 5.68±1.20 mm respectively whereas on the left side it was 5.07±1.12 mm and 5.76±1.29 mm respectively. The difference was statistically non-significant. Five types of shape were noted. Type I was predominant on right side, type IV was predominant on the left side.

CONCLUSION: variations in the number, shape and size of the foramen transversarium is not an uncommon phenomenon. Anatomical knowledge regarding such variations is clinically important since the course of the vertebral artery may be distorted in such situations and may result in vertebro-basilar insufficiency. Data provided in this study can be useful in interpretation of radiographic images (computerized tomography and angiograms).

PMID:34169994 | DOI:10.5137/1019-5149.JTN.32701-20.3

Chin J Physiol. 2021 May-Jun;64(3):125-128. doi: 10.4103/cjp.cjp_106_20.

ABSTRACT

Completing an ultramarathon leads to an immediate postrace surge of erythropoietin (EPO). Patients with chronic liver disease may have high plasma EPO concentrations. This study aims to explore whether plasma EPO concentrations vary between hepatitis B virus carrier (HBVc) and non-HBVc runners during long distance running. Blood samples were collected from 8 HBVc and 18 non-HBVc runners at 3 different time points: 1 week before, immediately following, and then 24 h after the 100-km ultramarathon race. Samples were analyzed for plasma EPO levels. EPO concentration had a statistically significant rise immediately after the race (8.7 [7.1-11.9] mU·mL^-1 to 23.7 [14.8-37.2] mU·mL^-1, P < 0.001) and maintained the high levels 24 h after the race finished (16.7 [11.5-21.0] mU·mL^-1, P < 0.001) in all participants. The mean of EPO concentration was 8.9 (5.7-13.2) mU·mL^-1 in HBVc runners and was 8.7 (7.7-11.2) mU·mL^-1 in non-HBVc runners in the prerace. In HBVc runners, plasma EPO levels were no different at baseline (P = 0.657) and increased in the same fashion in response to ultramarathon compared with non-HBVc runners. Plasma EPO levels between the two groups were not statistically different at any time point. Prolonged endurance exercise led to a significant increase in EPO. A comparable increase in EPO levels was observed in HBVc and non-HBVc runners during and 24 h after 100-km ultramarathon. However, a small sample size might have affected the ability to detect a difference if it does exist.

PMID:34169917 | DOI:10.4103/cjp.cjp_106_20

Chin J Physiol. 2021 May-Jun;64(3):129-134. doi: 10.4103/cjp.cjp_2_21.

ABSTRACT

When irisin and adropin were discovered, it was popularly hoped that they would become therapies for metabolic disorders that threaten global health. However, contradictory results have been reported in the subsequent period. Irisin, induced by exercise or cold exposure, is believed to be a myokine that causes the browning of adipose tissue thus increasing energy expenditure. Adropin is thought to be beneficial for health by regulating blood flow, capillary density, and playing an active role in glucose and insulin homeostasis. However, there were no experimental studies investigating the simultaneous effect of exercise and cold exposure in humans. The purpose of this study was to investigate irisin and adropin responses in young healthy individuals performing aerobic exercise in different environmental temperatures. Twenty-seven young, healthy individuals participated in this study. Participants performed 40 min of aerobic running exercise in environmental temperatures of 0°C, 12°C, and 24°C. Venous blood samples were taken pre- and post-exercise. Irisin and adropin levels were analyzed using an enzyme-linked immunosorbent assay. The principal findings showed that while serum irisin concentrations significantly increased after aerobic exercise was performed at an environmental temperature of 0°C, there was no significant difference between pre- and post-exercise recordings for physical activity performed at 12°C and 24°C. Adropin concentrations, however, remained unchanged between pre- and post-exercise at 0°C, 12°C, and 24°C. Interestingly, the exercise at 0°C caused an increase in adropin (12.5%), but this amount was not enough to be a statistically significant result. The findings of this study suggest that aerobic exercise in a cold environment causes greater irisin release. However, the combined effect of exercise and cold exposure may not be enough to statistically increase adropin level.

PMID:34169918 | DOI:10.4103/cjp.cjp_2_21

Biomed Instrum Technol. 2020 Jun 1;54(s1):53-63. doi: 10.2345/0899-8205-54.s3.53.

ABSTRACT

The requirements for the irradiation of healthcare products have been well established and implemented across the globe for several decades. The ISO 11137 series of standards gives the user the road map for designing a radiation process that will routinely deliver the required sterility assurance level so that product consistently meets specifications. The latest addition to the ISO 11137 series of standards should provide much-needed guidance around establishing a highly reproducible process based on a statistical analysis of the validated state of control. Most industries refer to this as “process control.”

PMID:34169973 | DOI:10.2345/0899-8205-54.s3.53

Neurol India. 2021 May-Jun;69(3):686-691. doi: 10.4103/0028-3886.319217.

ABSTRACT

BACKGROUND: Endothelial nitric oxide synthase (eNOS) is an enzymatic marker whose genetic polymorphism might predispose to acute ischemic stroke (AIS) via vascular endothelial dysfunction. It has a potential role in atherosclerosis, making it a plausible risk factor for stroke. Prior studies have failed to prove a conclusive relationship between eNOS polymorphism and AIS.

OBJECTIVE: The aim of this study is to find an association between the presence of eNOS polymorphism (Glu298Asp) and the risk of developing AIS.

MATERIALS AND METHODS: We recruited 307 subjects including 153 AIS cases and 154 healthy controls. The eNOS (Glu298Asp) polymorphism was identified in EDTA blood by PCR amplification of the target region followed by restriction enzyme digestion, and genotyping on Agarose gel. GG, GT and TT genotypes were obtained. Statistical analysis was done using SPSS software version 20.

RESULTS: A significant association was found between the presence of TT genotype and the risk of AIS (Odd’s ratio (OR): 2.43, P-value = 0.038). There was no significant association between the TT genotype and the traditional stroke risk factors. However, the TT genotype was significantly associated with the presence of altered consciousness (OR: 5.27, 95% CI: 1.59-17.04, P-value = 0.003) and with the occurrence of seizures at presentation (OR: 7.98, 95% CI: 1.99-32.09, P-value = 0.007).

CONCLUSIONS: There is a significant association between the presence of eNOSpolymorphism (Glu298Asp) and the risk of AIS, and the TT genotype may predispose to a more severe initial presentation of ischemic stroke.

PMID:34169869 | DOI:10.4103/0028-3886.319217