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1

Sensitivity analysis of model parameters for water quality simulation

100%
Naidoo N., Kumarasamy M.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 4
The Hybrid Cells in Series model consists of a plug flow cell – first and second well-mixed cells in series that represent advective-dispersive transport pollutants in river reaches. The key model parameters are the cell residence times (α, T1, and T2), which require parameter optimization to calibrate the model and to identify the sensitivity of model parameters. The least square error optimization method was used to determine the model parameters. Tracer test data was adopted to evaluate the sensitivity of the hybrid model response to a unit impulse input of a conservative pollutant. Factor perturbation was applied to determine the parameter with the greatest influence on hybrid unit output. The nth hybrid unit output was generated using a convolution technique and compared to the observed output from available field data. Traditionally, the longitudinal dispersion coefficient (DL) of a particular waterway is calculated according to the physical flow and channel properties. These properties are hardly regular, and the investigation into the use of moments to determine DL helps to eliminate uncertainties for future hydraulic modelling ventures. Parameters α and T2 are more sensitive, needing accurate estimation to correctly reproduce concentration-time profile, and to simulate river water quality.
2

Enthesopathic patterns of two South African female cadavers

81%
Naidoo N., Lazarus L., Satyapal K. S.
Folia Morphologica
|
2017
|
tom 76
|
nr 2
Enthesopathy is considered to be an osseous phenomenon, either disease-specific or bone-site specific, which occurs at the enthesis of bone. Upon routine cadaveric dissection of the glenohumeral region in two Caucasian females, enthesopathy of the right proximal humerus was observed unilaterally in both cases. Case 1 exhibited an inconsistent pattern of bony protuberances and crests dispersed across the lesser and greater tuberosities of the right humeral head. Varying degrees of ossification of the distal subscapularis muscle was also observed. Case 2 presented with a distinctively large enthesophyte that protruded supero-medially from the proximal right humerus. In addition, ossification of the distal-most aspect of the supraspinatus muscle was identified. Cases 1 and 2 were both reflective of osteophytic enthesopathy as proliferative change was clearly visible on the proximal aspect of each humerus. Whilst the presence of enthesopathies may be indicative of underlying pathology, it may prove beneficial to the field of bioarchaeology for the remodelling of lifestyles of ancient civilizations through the provision of current day variations as seen in these two case studies. (Folia Morphol 2017; 76, 2: 326–330)
3

An anatomical investigation of the carotid canal

81%
Naidoo N., Lazarus L., Ajayi N. O., Satyapal K. S.
Folia Morphologica
|
2017
|
tom 76
|
nr 2
Background: The carotid canal (CC) located in the petrous temporal bone transmits the internal carotid artery, internal carotid venous plexus and sympathetic nerve plexus from the neck into the cranial cavity. It is an accessible passage into the cranial cavity and is considered an important anatomical landmark for neurosurgeons. The aim of this study was to investigate the topographical, morphometric and morphological parameters of the CC. Materials and methods: An examination of the CC and related adjacent structures in 81 dry skull specimens was performed. Distribution of sample by sex was 34 females and 47 males, and by race 77 African and 4 Caucasian. The mean age was 50 years (range: 14–100 years). Results: The external opening of the CC was found to be round-shaped, oval-shaped and tear-drop-shaped in 28.4%, 49.4% and 22.2% of the specimens, respectively. (1) Mean diameters [mm]: (a) medio-lateral 7.52 mm and (b) antero- -posterior 5.41mm. Statistically significant difference in the vertical diameter was recorded in the race groups and laterality of the samples. (2) Mean distances [mm] between: (a) medial margins of external opening of CC was 50.03 mm, (b) lateral margins of external opening of CC was 62.73 mm and (c) external openings of CC and foramen lacerum was 15.6 mm. There was a statistically significant correlation between race and location of the opening of external CC in relation to foramen lacerum (viz. postero-lateral, lateral and diagonal, and lateral). Conclusions: The present study corroborated previous reports on the CC; however, the tear-drop shaped external CC opening was a unique finding. The knowledge of the reference measurements pertaining to the CC and its relationship to adjacent structures may postulate a suitable surgical “safe-zone” range within the CC area. (Folia Morphol 2017; 76, 2: 289–294)
4

Determination of the median nerve safe-zone in the carpal tunnel using the distal forearm bony prominences

81%
Ajayi N. O., Naidoo N., Lazarus L., Satyapal K. S.
Folia Morphologica
|
2014
|
tom 73
|
nr 4
Background: The compression of the median nerve (MN) in the carpal tunnel (CT) is one of the most common aetiologies of entrapment neuropathy syndromes in clinical practice. The aim of this study was to investigate the relationship of the palpable bony prominences of the distal forearm (radial styloid process [RSP] and ulnar styloid process [USP]) with MN in the CT, in order to determine a safe-zone of the MN during carpal tunnel procedures. Materials and methods: This study involved the bilateral dissection of the CT region of 30 adult cadaveric specimens (n = 60). Results: The mean distance between the RSP and USP was 49.34 mm. The mean distance of the MN from the RSP and the USP were 22.44 mm and 26.66 mm, respectively. The mean diameter of the MN within the CT deep to the flexor retinaculum was 5.93 mm. In addition, the MN was located postero-lateral and postero-medial to palmaris longus tendon (PLT) in 78.33% and 21.67% of specimens, respectively. Conclusions: This study found that the MN was located less than 60% of the RSP-USP distance from the RSP. Furthermore, the MN was mostly located postero-lateral to the PLT. Therefore, injection or surgical incision made at/medial to a point 60% of the RSP-USP distance from the RSP will be outside the safe-zone of the MN. The knowledge of this surface anatomical relationship of the MN may be useful during decompression for CT syndrome. (Folia Morphol 2014; 73, 4: 409–413)
5

Long head of biceps brachii tendon and transverse humeral ligament morphometry and their associated pathology

81%
Khan R., Satyapal K. S., Naidoo N., Lazarus L.
Folia Morphologica
|
2020
|
tom 79
|
nr 2
Background: As a dynamic stabiliser and flexor of the glenohumeral joint, the long head of the biceps brachii tendon (LHBBT) is further stabilised by the retinacular activities of the transverse humeral ligament (THL). Materials and methods: The LHBBT and THL which were obtained from a total of 40 cadaveric upper limb specimens (n = 80; females: 36, males: 44; right: 40, left: 40), were bilaterally dissected and subjected to morphometric evaluation. Results: The results are in millimetres. LHBBT length: 81.99 ± 21.28 right, 79.73 ± ± 17.27 left; 79.82 ± 19.66 male, 82.14 ± 19.03 female; LHBBT width: 4.28 ± ± 1.31 right, 4.67 ± 1.43 left; 4.35 ± 1.17 male, 4.63 ± 1.60 female; THL length: 20.91 ± 5.24 right, 21.19 ± 6.63 left; 21.52 ± 5.71 male, 20.48 ± 5.92 female; THL width: 16.65 ± 6.92 right, 16.63 ± 7.49 left; 16.83 ± 6.65 male, 16.40 ± 7.84 female. With larger LHBBT length observed on the right side and larger LHBBT width observed on the left side; both parameters appeared to be distinctly longer in female individuals. On the contrary, the THL length and width were evidently greater in male individuals, with larger lengths and widths present on the left and right sides respectively. Conclusions: These findings may contribute to South African literature and to clinical knowledge as these parameters are important in the successful outcomes of tenotomy, tenodesis and shoulder-related procedures. (Folia Morphol 2020; 79, 2: 359–365)
6

The variant course of the suprascapular artery

81%
Naidoo N., Lazarus L., De Gama B. Z., Satyapal K. S.
Folia Morphologica
|
2014
|
tom 73
|
nr 2
The suprascapular artery (SSA) has been identified to be of clinical relevance in surgical intervention and fracture healing of the shoulder. Despite the classic description of its course and relation to the superior transverse scapular ligament, it is subject to much variation. The aims of this study were: (i) to describe the course of the SSA in relation to the superior transverse scapular ligament, (ii) to determine the prevalence of the course of the SSA in relation to the superior transverse scapular ligament, (iii) to determine the prevalence of the variant origin of the SSA in cases presenting with variant course of the latter, and (iv) to establish a difference in laterality and that between adults and foetuses. The course of the SSA was investigated through the macro- and microdissection of the antero- and postero-superior shoulder regions of 31 adult and 19 foetal cadaveric specimens (n = 100). The SSA was observed to pass inferior to the superior transverse scapular ligament accompanied by the suprascapular nerve (20%), which corroborated the findings of previous studies. Subsequently, this variant course of the SSA also appeared to present with the variant origin of it in many instances (13%): from the 3rd part of the subclavian artery (4%), 1st part of the axillary artery (2%), 2nd part of the axillary artery (5%) and SSA (2%). Injury to the SSA may cause more serious trauma than that of arteries which are isolated from the great vessels, therefore the recognition and knowledge of variation in the origin and course of the SSA is significant in the treatment of diseases in the shoulder and cervical regions. Furthermore, the accompaniment of the suprascapular nerve with the SSA at the suprascapular notch inferior to the superior transverse scapular ligament may lead to neuropathy syndromes due to the pulsation of the artery against the nerve within the confined notch. (Folia Morphol 2014; 73, 2: 206–209)
7

An arthroscopic evaluation of the anatomical “critical zone”

81%
Naidoo N., Lazarus L., Osman S. A., Satyapal K. S.
Folia Morphologica
|
2017
|
tom 76
|
nr 2
Background: The “critical zone”, a region of speculated vascularity, is situated approximately 10 mm proximal to the insertion of the supraspinatus tendon. Despite its obvious role as an anatomical landmark demarcator, its patho-anatomic nature has been identified as the source of rotator cuff pathology. Although many studies have attempted to evaluate the vascularity of this region, the architecture regarding the exact length, width and shape of the critical zone, remains unreported. This study aimed to determine the shape and morphometry of the “critical zone” arthroscopically. Materials and methods: The sample series, which was comprised of 38 cases (n = 38) specific to pathological types, employed an anatomical investigation of the critical zone during routine real-time arthroscopy. Demographic representation: i) sex: 19 males, 19 females; ii) age range: 18–76 years; iii) race: white (n = 29), Indian (n = 7) and coloured (n = 2). Results: The incidence of shape and the mean lengths and widths of the critical zone were determined in accordance with the relevant demographic factors and patient history. Although the cresenteric shape was predominant, hemispheric and sail-shaped critical zones were also identified. The lengths and widths of the critical zone appeared markedly increased in male individuals. While the increase in age may account for the increased incidence of rotator cuff degeneration due to poor end-vascular supply, the additional factors of height and weight presented as major determinants of the increase in size of the critical zone. Conclusions: In addition, the comparisons of length and width with each other and shape yielded levels of significant difference, therefore indicating a directly proportional relationship between the length and width of the critical zone. This detailed understanding of the critical zone may prove beneficial for the success of post-operative rotator cuff healing. (Folia Morphol 2017; 76, 2: 277–283)
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