White hake (Urophycis tenuis) is a locally important commercial fish in the Gulf of St. Lawrence. The mean landings during the past 30 years have been about 6500 tonnes, the third most important demersal species. Despite this, little... more
White hake (Urophycis tenuis) is a locally important commercial fish in the Gulf of St. Lawrence. The mean landings during the past 30 years have been about 6500 tonnes, the third most important demersal species. Despite this, little biological work was conducted on this species before the early 1980's. Age determination is a key element in the analytical assessment process and this report attempts to define the age determination techniques, interpretation criteria, and growth estimated for white hake in the southern Gulf. White hake are often landed in a semi-processed state, head-off and gutted. A variety of conversion factors were investigated to account for this difficulty. The most satisfactory conversion was found to be total fish length to first dorsal fin length. An alternate conversion using otolith weight was also developed to estimate total length, and allow age determination, from a sample of heads only. A comparison of growth estimated from otoliths and vertebrae indicates both these hard parts exhibit the same pattern of ring formation. Marginal increment analysis indicates the slow growth zone ring is laid down in spring and early summer. Modal analysis of research survey length frequency data indicate year classes of fish at the same general size as determined from counting the rings on the otoliths. Growth of white hake is sexually dimorphic and is near linear for the ages most commonly found in the commercial fishery. From von Bertalanffy growth estimates, L GO for males is about 86 cm and for females is about 136 cm. These values appear reasonable compared to the largest fish caught in our annual resource surveys.
Hominin evolution featured shifts from a trunk shape suitable for climbing and housing a large gut to a trunk adapted to bipedalism and higher quality diets. Our knowledge regarding the tempo, mode, and context in which these derived... more
Hominin evolution featured shifts from a trunk shape suitable for climbing and housing a large gut to a trunk adapted to bipedalism and higher quality diets. Our knowledge regarding the tempo, mode, and context in which these derived traits evolved has been limited, based largely on a small-bodied Aus-tralopithecus partial skeleton (A.L. 288-1; " Lucy ") and a juvenile Homo erectus skeleton (KNM-WT 15000; " Turkana Boy "). Two recent discoveries, of a large-bodied Australopithecus afarensis (KSD-VP-1/1) and two Australopithecus sediba partial skeletons (MH1 and MH2), have added to our understanding of thorax evolution; however, little is known about thorax morphology in early Homo. Here we describe hominin vertebrae, ribs, and sternal remains from the Dinaledi chamber of the Rising Star cave system attributed to Homo naledi. Although the remains are highly fragmented, the best-preserved specimensdtwo lower thoracic vertebrae and a lower ribdwere found in association and belong to a small-bodied individual. A second lower rib may belong to this individual as well. All four of these individual elements are amongst the smallest known in the hominin fossil record. H. naledi is characterized by robust, relatively uncurved lower ribs and a relatively large spinal canal. We expect that the recovery of additional material from Rising Star Cave will clarify the nature of these traits and shed light on H. naledi functional morphology and phylogeny.
""Scoliotic vertebrae display asymmetric morphology. Previous research has remarked on the presence of this asymmetry, but it has not yet been quantified. The aim of this study was to produce a quantitative method by which to diagnose... more
""Scoliotic vertebrae display asymmetric morphology. Previous research has remarked on the presence of this asymmetry, but it has not yet been quantified. The aim of this study was to produce a quantitative method by which to diagnose scoliotic vertebral asymmetry and compare that method to morphological observations that are currently used to diagnose scoliosis in archaeological human remains. This was done in order to determine a quantitative method is viable in the context of time and effort. Transitional vertebrae (C1, C2, C7, T1, T2, T11, T12, L1, L2) of 74 individuals (666 vertebrae total) from five archaeological sites in the UK were analysed for asymmetry using sliding caliper linear measurements developed for this research. Asymmetric morphology considered suggestive of scoliosis was observed in 10 of the measured individuals for comparison. Intra- and inter-observer error, normality, outlier tests, multiple ANOVAs and test of directional asymmetry were applied to the data. Results indicate that patterns of asymmetry scores reflect the previously reported normal asymmetry observed by clinicians. The measurements were accurate but difficult to repeat by other observers. Though sample size was small, a baseline of normal asymmetry was determined, and scoliosis was detected most often as outliers over two standard deviations from the mean."
The detection of double edges in x-ray images of lumbar vertebrae is of prime importance in the assessment of vertebral injury or collapse that may be caused by osteoporosis and other spine pathology. In addition, if the above double-edge... more
The detection of double edges in x-ray images of lumbar vertebrae is of prime importance in the assessment of vertebral injury or collapse that may be caused by osteoporosis and other spine pathology. In addition, if the above double-edge detection process is conducted within an automatic framework, it would not only facilitate inexpensive and fast means of obtaining objective morphometric measurements on the spine, but also remove the human subjectivity involved in the morphometric analysis. This paper proposes a novel force-formulation scheme, termed as Pressurized Open Directional Gradient Vector Flow snakes, to discriminate and detect the superior and inferior double edges present in the radiographic images of the lumbar vertebrae. As part of the validation process, this algorithm is applied to a set of 100 lumbar images and the detection results are quantified using analyst-generated ground truth. The promising nature of the detection results bears testimony to the efficacy of the proposed approach
Small madtsoiid snakes referred to Patagoniophis and Alamitophis are represented by specimens of all major regions of the vertebral column from the Tingamarra Local Fauna (Early Eocene; Murgon, Queensland, Australia), and are diagnosed as... more
Small madtsoiid snakes referred to Patagoniophis and Alamitophis are represented by specimens of all major regions of the vertebral column from the Tingamarra Local Fauna (Early Eocene; Murgon, Queensland, Australia), and are diagnosed as distinct from members of the same genera from the Late Cretaceous (Campanian - ?Maastrichtian) of Patagonia, Argentina. The Tingamarra deposit has also produced ribs and dentary bones of two distinct morphotypes, which are provisionally assigned to the same two taxa. A single rib fragment represents a larger form comparable to South American Madtsoia spp., although not positively identifiable as a madtsoiid. It is inferred that two (and probably three) madtsoiid lineages had Antarctic-spanning distributions during the Late Cretaceous and/or Paleocene, with implications for their biology and that of their Neogene and Quaternary descendants.
Surgical treatment of spine-related injuries requires the placement of pedicle screws. Precise localization of the individual vertebrae and surrounding tissues is thus essential to avoid damage to nearby regions. Image-guided surgery can... more
Surgical treatment of spine-related injuries requires the placement of pedicle screws. Precise localization of the individual vertebrae and surrounding tissues is thus essential to avoid damage to nearby regions. Image-guided surgery can help in surgical planning and thus improve prognosis. During surgery, preoperative patient scans are registered to intraoperative scans which allows surgeons to track the location of the surgical tools and better visualize their position with respect to the actual anatomy. In this thesis, we present a semi-automated pipeline to segment the human spinal column in computed tomography scans. These segmented anatomical structures would thus act as a model to which the intraoperative scans are later registered. We incorporate a shape prior into geometric active contours to augment the segmentation produced using region and boundary based terms. We have also applied ideas based on anisotropic diffusion and flux computation to preprocess the volumes to address the challenges faced when working with CT scans, such as region inhomogeneities within and outside the spine and a lack of signal at the vertebral boundaries due to partial volume effects. We validate our approach on three datasets and achieve results comparable to the state of the art. Our method also provides good localization and segmentation of the spinal canal and intervertebral discs as offshoots.
A “long-backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12-13:6:4), a configuration acquired from a hominin-panin last... more
A “long-backed” scenario of hominin vertebral
evolution posits that early hominins possessed six
lumbar vertebrae coupled with a high frequency of four
sacral vertebrae (7:12-13:6:4), a configuration acquired
from a hominin-panin last common ancestor (PLCA)
having a vertebral formula of 7:13:6-7:4. One founding
line of evidence for this hypothesis is the recent assertion
that the “Lucy” sacrum (A.L. 288-1an, Australopithecus
afarensis) consists of four sacral vertebrae and a
partially-fused first coccygeal vertebra (Co1), rather
than five sacral vertebrae as in modern humans. This
study reassesses the number of sacral vertebrae in Lucy
by reexamining the distal end of A.L.288-1an in the context
of a comparative sample of modern human sacra
and Co1 vertebrae, and the sacrum of A. sediba (MH2).
Results demonstrate that, similar to S5 in modern
humans and A. sediba, the last vertebra in A.L. 288-1an
exhibits inferiorly-projecting (right side) cornua and a
kidney-shaped inferior body articular surface. This morphology
is inconsistent with that of fused or isolated Co1
vertebrae in humans, which either lack cornua or possess
only superiorly-projecting cornua, and have more
circularly-shaped inferior body articular surfaces. The
level at which the hiatus’ apex is located is also more
compatible with typical five-element modern human
sacra and A. sediba than if only four sacral vertebrae
are present. Our observations suggest that A.L. 288-1
possessed five sacral vertebrae as in modern humans;
thus, sacral number in “Lucy” does not indicate a directional
change in vertebral count that can provide information
on the PLCA ancestral condition.
Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a sternum, and a... more
Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a sternum, and a sacrum, are known from MH1 and MH2. Here, we describe these ~2.0 Ma fossils and provide raw data and plots of standardized measurements. We revisit the serial positions of the previously described vertebrae and ribs proposed in their initial announcements and provide revised identifications. Additionally, we include in our descriptions and analyses new axial material. Finally, we also test the hypothesis that multiple species are represented in the MH1 and MH2 material and specifically that MH1’s lumbar vertebrae belong to a member of the genus Homo, whereas those of MH2 belong to Australopithecus. We do not find support for this hypothesis, and instead attribute differences between MH1 and MH2 to their age difference and incomplete growth of the vertebral body in juvenile MH1.
Numbers of precaudal vertebrae are relatively stable in mammals, with cervical vertebrae fixed at seven in nearly all species, 19-20 thoracolumbar vertebrae (TL), and 29-30 precaudal vertebrae (PC), whereas the number of tail vertebrae is... more
Numbers of precaudal vertebrae are relatively stable in mammals, with cervical vertebrae fixed at seven in nearly all species, 19-20 thoracolumbar vertebrae (TL), and 29-30 precaudal vertebrae (PC), whereas the number of tail vertebrae is highly variable both within and between major clades. Hominoid primates have varyingly short trunks, generally between 16 (orangutans, eastern gorillas) and 18 (hylobatids) TL, 28-31 PC, and 1-5 coccygeal vertebrae (Co); they lack external tails. Researchers have focused mostly on numbers of PC and the observation that chimpanzees and especially bonobos (panins) possess more PC vertebrae than humans and other hominoids. More appropriately, if Co are included to yield a total vertebra count, humans and panins possess similar numbers of total vertebrae (TV=33). This is because humans tend to possess one less sacral segment and one more Co than panins. When combined, humans and panins possess 17 TL and 9 sacrocaudal vertebrae (SC). Together, the evidence from TV is best interpreted in a homeotic framework, which reflects the expression boundaries of underlying Hox genes. Hox10 expression boundaries correspond with the TL and SC borders; thus, a cranial shift of Hox10 expression in an ancestor with a chimpanzee- or bonobo-like vertebral formula (7C:13T:4L:6S:3Co; TV=33) would result in homeotic changes at the TL and SC boundaries while maintaining the integrity of the lumbosacral boundary (and TL number), resulting in a humanlike vertebral formula (7C:12T:5L:5S:4Co; TV=33). This evolutionary scenario involves neither the extensive homoplasy in extant apes nor reversals in human evolution proposed by some researchers.
The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an endangered small population, on which there... more
The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an endangered small population, on which there is scarce information regarding ecotoxicology or trophic ecology. Given that white shark’s sightings are rare in the Mediterranean and the possibility of obtaining samples is highly limited, the aim of this research was to provide general information regarding the concentration of trace elements and stable isotopes (δ15N and δ13C). Laboratory analyses were performed on 18 and 12 subsamples from two different white sharks’ vertebrae obtained from two adult specimens caught in 1987, in Favignana Island, Italy. Perforations were made along the vertebrae to describe both trace elements and stable isotopes at different life stages. A total of 38 trace elements were analysed, in which the highest concentrations were found in Fe, Sr, U, Pb, and Zn. The fluctuations of these elements during the ontogeny of both individuals could have been related to changes in diet and environment, although the specific origin remains unknown. Regarding stable isotopes, the vertebrae from the male showed an isotopic range from 9.6‰ to 10.8‰ (δ15N) and from −16.5‰ to −13.0‰ (δ13C) with a mean ± SD value of 10.3 ± 0.4‰ for δ15N and −14.6 ± 1.3‰ for δ13C; whereas the female vertebrae had an isotopic range from 9.8‰ to 11.1‰ (δ15N) and from −16.9‰ to −15.0‰ (δ13C), with a mean ± SD value of 10.8 ± 0.6‰ for δ15N and −15.8 ± 0.8‰ for δ13C. There were no significant δ15N differences (U = 6, p = 0.07346) between the two individuals. However, there were just significant differences in δ13C (t = −1.8, p = 0.049256), which could suggest sexual segregation in terms of habitat use and feeding habits.
Bomb radiocarbon analysis of vertebral growth bands was used to validate lifespan for sand tiger sharks (Carcharias taurus) from the western North Atlantic (WNA) and southwestern Indian Oceans (SIO). Visual counts of vertebral growth... more
Bomb radiocarbon analysis of vertebral growth bands was used to validate lifespan for sand tiger sharks (Carcharias taurus) from the western North Atlantic (WNA) and southwestern Indian Oceans (SIO). Visual counts of vertebral growth bands were used to assign age and estimate year of formation (YOF) for sampled growth bands in eight sharks from the WNA and two sharks from the SIO. Carbon-14 results were plotted relative to YOF for comparison with regional D 14 C reference chronologies to assess the accuracy of age estimates. Results from the WNA validated vertebral age estimates up to 12 years, but indicated that ages of large adult sharks were underestimated by 11–12 years. Age was also underestimated for adult sharks from the SIO by 14–18 years. Validated lifespan for C. taurus individuals in the present study reached at least 40 years for females and 34 years for males. Findings indicated that the current age-reading methodology is not suitable for estimating the age of C. taurus beyond ,12 years. Future work should investigate whether vertebrae of C. taurus record age throughout ontogeny, or cease to be a reliable indicator at some point in time.
The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an enda...
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this... more
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females) were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P < 0.05). Congenital spinal abnormalities were found in 29 ferrets (16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning.
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this... more
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females)were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P < 0.05). Congenital spinal abnormalities were found in 29 ferrets (16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning. C 2014 American College of Veterinary Radiology.
The Cobb angle measurement of the scoliotic spine is prone to inter- and intra-observer variations in the clinical setting. This paper proposes a deep learning architecture for detecting spine vertebrae from X-ray images to evaluate the... more
The Cobb angle measurement of the scoliotic spine is prone to inter- and intra-observer variations in the clinical setting. This paper proposes a deep learning architecture for detecting spine vertebrae from X-ray images to evaluate the Cobb angle automatically. The public AASCE MICCAI 2019 anterior-posterior X-ray image dataset and local images were used to train and test the proposed convolutional neural network architecture. Sixty-eight landmark features of the spine were detected from the input image to obtain seventeen vertebrae on the spine. The vertebrae locations obtained were processed to automatically measure the Cobb angle. The proposed method can measure the Cobb angle with accuracies up to 93.6% and has excellent reliability compared to clinicians’ measurement (intraclass correlation coefficient > 0.95). The proposed deep learning architecture may be used as a tool to augment Cobb angle measurement in X-ray images of patients with adolescent idiopathic scoliosis in a...
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this... more
Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females) were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Congenital spinal abnormalities were found in 29 ferrets (16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning.
Spinal fusion is a standard surgical treatment for patients suffering from low back pain attributed to disc degeneration. However, results are somewhat variable and unpredictable. With fusion the kinematic behaviour of the spine is... more
Spinal fusion is a standard surgical treatment for patients suffering from low back pain attributed to disc degeneration. However, results are somewhat variable and unpredictable. With fusion the kinematic behaviour of the spine is altered. Fusion and/or stabilizing implants carrying considerable load and prevent rotation of the fused segments. Associated with these changes, a risk for accelerated disc degeneration at the adjacent levels to fusion has been demonstrated. However, there is yet no method to predict the effect of fusion surgery on the adjacent tissue levels, i.e. bone and disc. The aim of this study was to develop a coupled and patient-specific mechanoregulated model to predict disc generation and changes in bone density after spinal fusion and to validate the results relative to patient follow-up data. To do so, a multiscale disc mechanoregulation adaptation framework was developed and coupled with a previously developed bone remodelling algorithm. This made it possible to determine extra cellular matrix changes in the intervertebral disc and bone density changes simultaneously based on changes in loading due to fusion surgery. It was shown that for 10 cases the predicted change in bone density and degeneration grade conforms reasonable well to clinical follow-up data. This approach helps us to understand the effect of surgical intervention on the adjacent tissue remodelling. Thereby, providing the first insight for a spine surgeon as to which patient could potentially be treated successfully by spinal fusion and in which patient has a high risk for adjacent tissue changes.
