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  • Open Access
    Authors: 
    Vikraman Selvaraja; Marco L. Fiorentini; Crystal LaFlamme; Boswell A. Wing; Thi Hao Bui;
    Publisher: Geological Society of America

    The cycle of sulfur, an important volatile in Earth9s crust, is the driver of many significant processes such as biological evolution, climate change, and the formation of ore deposits. This study investigates the ancient cycle of volatiles by tracing the indelible signal of anomalous sulfur isotopes, expressed as Δ 33 S ≠ 0, to illuminate the pathway of sulfur recycling through magmatic arcs. We selected the ca. 2.0 Ga Glenburgh gold deposit in the Glenburgh magmatic arc of Western Australia as a natural laboratory for this study. High-precision multiple sulfur isotope analyses of samples from the Glenburgh gold deposit and surrounding granitoid rocks yield the largest known sulfur isotope anomalies (Δ 33 S up to +0.82‰) in rocks 2.33 Ga. Multiple sulfur isotope data are able to clarify a process that is cryptic to most other currently available data sets, showing that the cycling of volatiles and metals in arc settings occurs on very large scales, from the atmosphere-hydrosphere through to the lithosphere during crustal generation.

  • Open Access English
    Authors: 
    Kurji HM; Ono Y; Nelson AA; More KD; Wong B; Dyke C; Boorman RS; Thornton GM; Lo IK;
    Publisher: Dove Medical Press

    Hafeez M Kurji,1 Yohei Ono,2,3 Atiba A Nelson,2 Kristie D More,2 Ben Wong,4 Corinne Dyke,4 Richard S Boorman,2 Gail M Thornton,2,5 Ian KY Lo2 1College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada; 2Department of Surgery, Section of Orthopaedic Surgery, McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada; 3Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan; 4Department of Radiology, University of Calgary, Calgary, AB, Canada; 5Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada Background: Arthroscopic repair of type II superior labrum from anterior to posterior (SLAP) lesions is a common surgical procedure. However, anatomic healing following repair has rarely been investigated. The intraobserver and interobserver reliability of magnetic resonance imaging arthrography (MRA) following type II SLAP repair has not previously been investigated. This is of particular interest due to recent reports of poor clinical results following type II SLAP lesion repair. Purpose: To evaluate the MRA findings following arthroscopic type II SLAP lesion repair and determine its intraobserver and interobserver reliability. Study design: Cohort study (diagnosis), Level of Evidence, 2. Methods: Twenty-five patients with an isolated type II SLAP lesion (confirmed via diagnostic arthroscopy) underwent standard suture anchor-based repair. At a mean of 25.2 months postoperatively, patients underwent a standardized MRA protocol to investigate the integrity of the repair. MRAs were independently reviewed by two radiologists and a fellowship trained shoulder surgeon. The outcomes were classified as healed SLAP repair or re-torn SLAP repair. Results: On average, 54% of MRAs were interpreted as healed SLAP repairs while 46% of MRAs were interpreted as having a re-torn SLAP repair. Overall, only 43% of the studies had 100% agreement across all interpretations. The intraobserver reliability ranged from 0.71 to 0.81 while the interobserver reliability between readers ranged from 0.13 to 0.44 (Table 1). Conclusion: The intraobserver agreement of MRA in the evaluation of type II SLAP repair was substantial to excellent. However, the interobserver agreement of MRA was poor to fair. As a result, the routine use of MRA in the evaluation of type II SLAP lesion repair should be utilized with caution. A global evaluation of the patient, including detailed history and physical examination, is paramount in determining the cause of failure and one should not rely on MRA alone. Keywords: SLAP, MRA, labrum, postoperative

  • Open Access English
    Authors: 
    John C. Hogenbirk; Margaret G. French; Patrick E. Timony; Roger Strasser; Dan Hunt; Raymond W. Pong;
    Publisher: BMJ Publishing Group

    Introduction The Northern Ontario School of Medicine (NOSM) has a social accountability mandate to serve the healthcare needs of the people of Northern Ontario, Canada. A multiyear, multimethod tracking study of medical students and postgraduate residents is being conducted by the Centre for Rural and Northern Health Research (CRaNHR) in conjunction with NOSM starting in 2005 when NOSM first enrolled students. The objective is to understand how NOSM9s selection criteria and medical education programmes set in rural and northern communities affect early career decision-making by physicians with respect to their choice of medical discipline, practice location, medical services and procedures, inclusion of medically underserved patient populations and practice structure. Methods and analysis This prospective comparative longitudinal study follows multiple cohorts from entry into medical education programmes at the undergraduate (UG) level (56–64 students per year at NOSM) or postgraduate (PG) level (40–60 residents per year at NOSM, including UGs from other medical schools and 30–40 NOSM UGs who go to other schools for their residency training) and continues at least 5 years into independent practice. The study compares learners who experience NOSM UG and NOSM PG education with those who experience NOSM UG education alone or NOSM PG education alone. Within these groups, the study also compares learners in family medicine with those in other specialties. Data will be analysed using descriptive statistics, χ2 tests, logistic regression, and hierarchical log-linear models. Ethics and dissemination Ethical approval was granted by the Research Ethics Boards of Laurentian University (REB #2010-08-03 and #2012-01-09) and Lakehead University (REB #031 11-12 Romeo File #1462056). Results will be published in peer-reviewed scientific journals, presented at one or more scientific conferences, and shared with policymakers and decision-makers and the public through 4-page research summaries and social media such as Twitter (@CRaNHR, @NOSM) or Facebook.

  • Closed Access
    Authors: 
    Matthew G. King; Matthew E. Horning; Eric H. Roalson;
    Publisher: Wiley

    The distribution of many species inhabiting northwestern North America has been heavily influenced by the climatic changes during the late Pleistocene. Several studies have suggested that species were restricted to glacial refugia north and/or south of the continental ice sheet front. It is also hypothesized that the coast of northwestern North America could have been a prime location for glacial refugia because of the lowering of the eustatic sea level and the concomitant rise of the continental shelf because of tectonic rebound. Alternatively, some coastal species distributions and demographics may have been unaffected in the long-term by the last glacial maximum (LGM). We tested the glacial refugium hypothesis on an obligate coastal plant species, Carex macrocephala by sampling 600 individuals from 41 populations with 11 nuclear microsatellite loci and the rpL16 plastid intragenic spacer region. The microsatellite data sets suggest a low level of population differentiation with a standardized G'(ST) = 0.032 and inbreeding was high with an F = 0.969. The homogenization of the populations along the coast was supported by a principal coordinate analysis, amovas and samova analyses. Analyses using the rpL16 data set support the results of the microsatellite analyses, with a low F(ST) of 0.042. Coalescent and mismatch analyses using rpL16 suggest that C. macrocephala has not gone through a significant bottleneck within the past 100,000 years, although a much earlier population expansion was indicated by the mismatch analysis. Carex macrocephala exhibits the characteristics of metapopulation dynamics and on the basis of these results, we concluded that it was not restricted to glacial refugia during the LGM, but that it existed as a large metapopulation.

  • Publication . Article . Other literature type . 2019
    Open Access
    Authors: 
    Richard Ohrbach; Gary D. Slade; Eric Bair; Nuvan Rathnayaka; Luda Diatchenko; Joel D. Greenspan; William Maixner; Roger B. Fillingim;
    Publisher: Wiley

    BACKGROUND Multiple risk factors predict temporomandibular disorders (TMD) onset, but temporal changes in risk factors and their contribution to risk of TMD have not been evaluated. The study aims were to (a) describe changes occurring in premorbid TMD risk factors when re-measured at TMD onset and 6 months later, and (b) determine if measures of change improve accuracy in predicting TMD incidence compared to premorbid measures alone. METHODS In this observational prospective cohort study at four university research clinics, 3,258 community-based, 18- to 44-year-olds without TMD were enrolled. During the 3-year median follow-up, 260 incident cases of first-onset TMD were identified, and 196 TMD-free subjects were selected as matched controls. Six-months later, 147 of 260 incident cases (56.6%) were re-examined revealing 72 (49%) with 'persistent TMD' and 75 (51%) whose condition had resolved ('transient TMD'). Virtually all (126) of the 127 re-examined controls remained without TMD. Questionnaires and clinical measurements evaluated risk factors from clinical, health, psychological and behavioural and neurosensory domains. RESULTS Most risk factors across all four domains increased with TMD onset, remained elevated in the persistent group and declined in the transient group (i.e., significant ANOVA interactions, p < .05). Accuracy in predicting first-onset TMD, quantified as area under the receiver operating characteristic curve was 0.71 (95% CL 0.68, 0.73) using only premorbid measures of risk factors, which increased to 0.91 (95% CL 0.89, 0.94) after addition of change measures. CONCLUSIONS TMD pain onset and persistence appear to be determined by enduring characteristics of the person as well as mutually interactive with temporally evolving variables. SIGNIFICANCE TMD is known to be a complex disorder, in which onset and persistence are associated with disease-related variables in multiple domains, including environmental exposure, clinical, psychological, health status, and pain processing variables. Using a more dynamic approach in order to capture change across time, many aspects of those domains were found to worsen prior to the reporting of pain, with bidirectional influences between domains and pain emergence likely. TMD onset appears to represent the cumulative effect of multiple system dysregulation.

  • Closed Access
    Authors: 
    G Gábor; R.G. Sasser; John P. Kastelic; Miklós Mézes; Gy Falkay; S Bozó; J Völgyi Csik; I Bárány; A Hidas; F Szász; +1 more
    Publisher: Elsevier BV

    The objectives of this study were to determine relationships between scrotal size (SC; estimated from a video image) and testicular size, and between ultrasonographic echotexture of the testis and seminiferous tubule area in bulls. Video images of the scrotum of 49 Holstein-Friesian (H-F) bulls were recorded and digitized. Scrotal width and length were measured with custom software. After slaughter, scrotums (containing testes) were excised, SC and testicular height, width and volume were measured, and the testes were examined ultrasonographically. Correlations between SC and testicular width or volume (r = 0.86, P < 0.001 and r = 0.84, P < 0.001, respectively) were much higher than those between scrotal width and testicular width or volume (r = 0.23, P < 0.11 and r = 0.28, P < 0.06). Histological examination of the testes was performed in 31 of the bulls. Ultrasonographic echotexture of the testes (determined with custom software) was highly correlated (r = -0.5, P < 0.005) with seminiferous tubule area. Although SC was superior to video imaging for estimating testicular size, ultrasonographic imaging of the testes has considerable potential for the evaluation of testicular function in bulls.

  • Authors: 
    Dexter Barrows; Barry Vuong; Kenneth Eng Kian Lee; Jamil Jivraj; Victor X. D. Yang;
    Publisher: SPIE

    Endovascular Optical Coherence Tomography (OCT) has previously been used in both bench-top and clinical environments to produce vascular images, and can be helpful in characterizing, among other pathologies, plaque build-up and impedances to normal blood ow. The raw data produced can also be processed to yield high- resolution blood velocity information, but this computation is expensive and has previously only been available a posteriori using post-processing software. Real-time Doppler OCT (DOCT) imaging has been demonstrated before in the skin and eye, but this capability has not been available to vascular surgeons. Graphics Processing Units (GPUs) can be used to dramatically accelerate this type of distributed computation. In this paper we present a software package capable of real-time DOCT processing and circular image display using GPU acceleration designed to operate with catheter-based clinical OCT systems. This image data is overlayed onto structural images providing clinicians with live, high-resolution blood velocity information to complement anatomical data.

  • Closed Access
    Authors: 
    Anna S. Karyagina; Vladimir G. Lunin; Irene Ya. Levtchenko; Diane Labbé; Roland Brousseau; Peter C. K. Lau; Irene I. Nikolskaya;
    Publisher: Elsevier BV
    Country: Canada

    Abstract Overproduction of the Nla X DNA methyltransferase (M· Nla X) in an Escherichia coli host conferred resistance to Sso II restriction endonuclease (R· Sso II) digestion. This suggested an overlap of sequence specificity between M· Nla X and M· Sso II, the latter of which modifies the internal cytosine of the target sequence 5′-CCNGG-3′. A variant of M· Nla X (M· Sso/Nla ), containing an N-terminal extension from M· Sso II, was also enzymatically active. Using deletion analysis, the N-terminal 71 amino-acid residues of M· Sso II were shown to be essential for modification activity.

  • Open Access
    Authors: 
    Yan Yang; Xing Chen; Young Soo Choi; Bo-Seon Kang;
    Publisher: Hindawi Limited

    1Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Ministry of Education, Chongqing 400054, China 2Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 3Department of Bioengineering, University of Washington, Seattle, WA 98195-5061, USA 4Department of Mechanical System Engineering, Chonnam National University, Gwangju 500757, Republic of Korea

  • Open Access
    Authors: 
    John Githaka Maringa; Anthony R. Vega; Michael W. Davidson; Khuloud Jaqaman; Nicolas Touret;
    Publisher: Elsevier BV

    CD36 is a multiligand scavenger receptor that ligates Thrombospondin-1 (TSP-1) at the surface of endothelial cells and induces their apoptosis. Recent evidences have shown that clustering of CD36 is necessary for signal transduction in macrophages and is regulated by the architecture of the cortical actin cytoskeleton apposed to the plasmalemma. Here, we investigated the role of the cortical actin cytoskeleton and plasma membrane nanodomains in the control of CD36 activation in endothelial cells. Stimulation with multivalent ligands (TSP-1 and anti-CD36 IgM) resulted in the downstream phosphorylation of the Src Family kinase, Fyn. Disruption of the actin cytoskeleton or removal of cholesterol blocked this activation. To gain molecular details on the rearrangement of the receptors during TSP-1 binding, we conducted superresolution approaches (based on PhotoActivated Localization Microscopy or PALM) and quantitative spatial distribution analysis. Endothelial cell lines stably expressing CD36-PAmCherry were generated for that purpose. At steady state, CD36 receptors pre-exist in small clusters (average diameter of 100 nm), in which Fyn was also present. Upon TSP-1 binding, CD36 clusters increased in size (average diameter of 140 nm) and also became denser. The average distance between CD36 molecules in these clusters was in the range of 8 nm compare to 11 nm in the control condition. F-actin depolymerization or cholesterol depletion reduced the capacity of the ligand to induce formation of larger clusters resulting in a decreased recruitment and activation of Fyn. Our data demonstrate cooperation between cholesterol-dependent domains and the cortical actin cytoskeleton in the organization of CD36 receptors and Fyn before and during TSP-1 stimulation.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
415,126 Research products, page 1 of 41,513
  • Open Access
    Authors: 
    Vikraman Selvaraja; Marco L. Fiorentini; Crystal LaFlamme; Boswell A. Wing; Thi Hao Bui;
    Publisher: Geological Society of America

    The cycle of sulfur, an important volatile in Earth9s crust, is the driver of many significant processes such as biological evolution, climate change, and the formation of ore deposits. This study investigates the ancient cycle of volatiles by tracing the indelible signal of anomalous sulfur isotopes, expressed as Δ 33 S ≠ 0, to illuminate the pathway of sulfur recycling through magmatic arcs. We selected the ca. 2.0 Ga Glenburgh gold deposit in the Glenburgh magmatic arc of Western Australia as a natural laboratory for this study. High-precision multiple sulfur isotope analyses of samples from the Glenburgh gold deposit and surrounding granitoid rocks yield the largest known sulfur isotope anomalies (Δ 33 S up to +0.82‰) in rocks 2.33 Ga. Multiple sulfur isotope data are able to clarify a process that is cryptic to most other currently available data sets, showing that the cycling of volatiles and metals in arc settings occurs on very large scales, from the atmosphere-hydrosphere through to the lithosphere during crustal generation.

  • Open Access English
    Authors: 
    Kurji HM; Ono Y; Nelson AA; More KD; Wong B; Dyke C; Boorman RS; Thornton GM; Lo IK;
    Publisher: Dove Medical Press

    Hafeez M Kurji,1 Yohei Ono,2,3 Atiba A Nelson,2 Kristie D More,2 Ben Wong,4 Corinne Dyke,4 Richard S Boorman,2 Gail M Thornton,2,5 Ian KY Lo2 1College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada; 2Department of Surgery, Section of Orthopaedic Surgery, McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada; 3Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan; 4Department of Radiology, University of Calgary, Calgary, AB, Canada; 5Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada Background: Arthroscopic repair of type II superior labrum from anterior to posterior (SLAP) lesions is a common surgical procedure. However, anatomic healing following repair has rarely been investigated. The intraobserver and interobserver reliability of magnetic resonance imaging arthrography (MRA) following type II SLAP repair has not previously been investigated. This is of particular interest due to recent reports of poor clinical results following type II SLAP lesion repair. Purpose: To evaluate the MRA findings following arthroscopic type II SLAP lesion repair and determine its intraobserver and interobserver reliability. Study design: Cohort study (diagnosis), Level of Evidence, 2. Methods: Twenty-five patients with an isolated type II SLAP lesion (confirmed via diagnostic arthroscopy) underwent standard suture anchor-based repair. At a mean of 25.2 months postoperatively, patients underwent a standardized MRA protocol to investigate the integrity of the repair. MRAs were independently reviewed by two radiologists and a fellowship trained shoulder surgeon. The outcomes were classified as healed SLAP repair or re-torn SLAP repair. Results: On average, 54% of MRAs were interpreted as healed SLAP repairs while 46% of MRAs were interpreted as having a re-torn SLAP repair. Overall, only 43% of the studies had 100% agreement across all interpretations. The intraobserver reliability ranged from 0.71 to 0.81 while the interobserver reliability between readers ranged from 0.13 to 0.44 (Table 1). Conclusion: The intraobserver agreement of MRA in the evaluation of type II SLAP repair was substantial to excellent. However, the interobserver agreement of MRA was poor to fair. As a result, the routine use of MRA in the evaluation of type II SLAP lesion repair should be utilized with caution. A global evaluation of the patient, including detailed history and physical examination, is paramount in determining the cause of failure and one should not rely on MRA alone. Keywords: SLAP, MRA, labrum, postoperative

  • Open Access English
    Authors: 
    John C. Hogenbirk; Margaret G. French; Patrick E. Timony; Roger Strasser; Dan Hunt; Raymond W. Pong;
    Publisher: BMJ Publishing Group

    Introduction The Northern Ontario School of Medicine (NOSM) has a social accountability mandate to serve the healthcare needs of the people of Northern Ontario, Canada. A multiyear, multimethod tracking study of medical students and postgraduate residents is being conducted by the Centre for Rural and Northern Health Research (CRaNHR) in conjunction with NOSM starting in 2005 when NOSM first enrolled students. The objective is to understand how NOSM9s selection criteria and medical education programmes set in rural and northern communities affect early career decision-making by physicians with respect to their choice of medical discipline, practice location, medical services and procedures, inclusion of medically underserved patient populations and practice structure. Methods and analysis This prospective comparative longitudinal study follows multiple cohorts from entry into medical education programmes at the undergraduate (UG) level (56–64 students per year at NOSM) or postgraduate (PG) level (40–60 residents per year at NOSM, including UGs from other medical schools and 30–40 NOSM UGs who go to other schools for their residency training) and continues at least 5 years into independent practice. The study compares learners who experience NOSM UG and NOSM PG education with those who experience NOSM UG education alone or NOSM PG education alone. Within these groups, the study also compares learners in family medicine with those in other specialties. Data will be analysed using descriptive statistics, χ2 tests, logistic regression, and hierarchical log-linear models. Ethics and dissemination Ethical approval was granted by the Research Ethics Boards of Laurentian University (REB #2010-08-03 and #2012-01-09) and Lakehead University (REB #031 11-12 Romeo File #1462056). Results will be published in peer-reviewed scientific journals, presented at one or more scientific conferences, and shared with policymakers and decision-makers and the public through 4-page research summaries and social media such as Twitter (@CRaNHR, @NOSM) or Facebook.

  • Closed Access
    Authors: 
    Matthew G. King; Matthew E. Horning; Eric H. Roalson;
    Publisher: Wiley

    The distribution of many species inhabiting northwestern North America has been heavily influenced by the climatic changes during the late Pleistocene. Several studies have suggested that species were restricted to glacial refugia north and/or south of the continental ice sheet front. It is also hypothesized that the coast of northwestern North America could have been a prime location for glacial refugia because of the lowering of the eustatic sea level and the concomitant rise of the continental shelf because of tectonic rebound. Alternatively, some coastal species distributions and demographics may have been unaffected in the long-term by the last glacial maximum (LGM). We tested the glacial refugium hypothesis on an obligate coastal plant species, Carex macrocephala by sampling 600 individuals from 41 populations with 11 nuclear microsatellite loci and the rpL16 plastid intragenic spacer region. The microsatellite data sets suggest a low level of population differentiation with a standardized G'(ST) = 0.032 and inbreeding was high with an F = 0.969. The homogenization of the populations along the coast was supported by a principal coordinate analysis, amovas and samova analyses. Analyses using the rpL16 data set support the results of the microsatellite analyses, with a low F(ST) of 0.042. Coalescent and mismatch analyses using rpL16 suggest that C. macrocephala has not gone through a significant bottleneck within the past 100,000 years, although a much earlier population expansion was indicated by the mismatch analysis. Carex macrocephala exhibits the characteristics of metapopulation dynamics and on the basis of these results, we concluded that it was not restricted to glacial refugia during the LGM, but that it existed as a large metapopulation.

  • Publication . Article . Other literature type . 2019
    Open Access
    Authors: 
    Richard Ohrbach; Gary D. Slade; Eric Bair; Nuvan Rathnayaka; Luda Diatchenko; Joel D. Greenspan; William Maixner; Roger B. Fillingim;
    Publisher: Wiley

    BACKGROUND Multiple risk factors predict temporomandibular disorders (TMD) onset, but temporal changes in risk factors and their contribution to risk of TMD have not been evaluated. The study aims were to (a) describe changes occurring in premorbid TMD risk factors when re-measured at TMD onset and 6 months later, and (b) determine if measures of change improve accuracy in predicting TMD incidence compared to premorbid measures alone. METHODS In this observational prospective cohort study at four university research clinics, 3,258 community-based, 18- to 44-year-olds without TMD were enrolled. During the 3-year median follow-up, 260 incident cases of first-onset TMD were identified, and 196 TMD-free subjects were selected as matched controls. Six-months later, 147 of 260 incident cases (56.6%) were re-examined revealing 72 (49%) with 'persistent TMD' and 75 (51%) whose condition had resolved ('transient TMD'). Virtually all (126) of the 127 re-examined controls remained without TMD. Questionnaires and clinical measurements evaluated risk factors from clinical, health, psychological and behavioural and neurosensory domains. RESULTS Most risk factors across all four domains increased with TMD onset, remained elevated in the persistent group and declined in the transient group (i.e., significant ANOVA interactions, p < .05). Accuracy in predicting first-onset TMD, quantified as area under the receiver operating characteristic curve was 0.71 (95% CL 0.68, 0.73) using only premorbid measures of risk factors, which increased to 0.91 (95% CL 0.89, 0.94) after addition of change measures. CONCLUSIONS TMD pain onset and persistence appear to be determined by enduring characteristics of the person as well as mutually interactive with temporally evolving variables. SIGNIFICANCE TMD is known to be a complex disorder, in which onset and persistence are associated with disease-related variables in multiple domains, including environmental exposure, clinical, psychological, health status, and pain processing variables. Using a more dynamic approach in order to capture change across time, many aspects of those domains were found to worsen prior to the reporting of pain, with bidirectional influences between domains and pain emergence likely. TMD onset appears to represent the cumulative effect of multiple system dysregulation.

  • Closed Access
    Authors: 
    G Gábor; R.G. Sasser; John P. Kastelic; Miklós Mézes; Gy Falkay; S Bozó; J Völgyi Csik; I Bárány; A Hidas; F Szász; +1 more
    Publisher: Elsevier BV

    The objectives of this study were to determine relationships between scrotal size (SC; estimated from a video image) and testicular size, and between ultrasonographic echotexture of the testis and seminiferous tubule area in bulls. Video images of the scrotum of 49 Holstein-Friesian (H-F) bulls were recorded and digitized. Scrotal width and length were measured with custom software. After slaughter, scrotums (containing testes) were excised, SC and testicular height, width and volume were measured, and the testes were examined ultrasonographically. Correlations between SC and testicular width or volume (r = 0.86, P < 0.001 and r = 0.84, P < 0.001, respectively) were much higher than those between scrotal width and testicular width or volume (r = 0.23, P < 0.11 and r = 0.28, P < 0.06). Histological examination of the testes was performed in 31 of the bulls. Ultrasonographic echotexture of the testes (determined with custom software) was highly correlated (r = -0.5, P < 0.005) with seminiferous tubule area. Although SC was superior to video imaging for estimating testicular size, ultrasonographic imaging of the testes has considerable potential for the evaluation of testicular function in bulls.

  • Authors: 
    Dexter Barrows; Barry Vuong; Kenneth Eng Kian Lee; Jamil Jivraj; Victor X. D. Yang;
    Publisher: SPIE

    Endovascular Optical Coherence Tomography (OCT) has previously been used in both bench-top and clinical environments to produce vascular images, and can be helpful in characterizing, among other pathologies, plaque build-up and impedances to normal blood ow. The raw data produced can also be processed to yield high- resolution blood velocity information, but this computation is expensive and has previously only been available a posteriori using post-processing software. Real-time Doppler OCT (DOCT) imaging has been demonstrated before in the skin and eye, but this capability has not been available to vascular surgeons. Graphics Processing Units (GPUs) can be used to dramatically accelerate this type of distributed computation. In this paper we present a software package capable of real-time DOCT processing and circular image display using GPU acceleration designed to operate with catheter-based clinical OCT systems. This image data is overlayed onto structural images providing clinicians with live, high-resolution blood velocity information to complement anatomical data.

  • Closed Access
    Authors: 
    Anna S. Karyagina; Vladimir G. Lunin; Irene Ya. Levtchenko; Diane Labbé; Roland Brousseau; Peter C. K. Lau; Irene I. Nikolskaya;
    Publisher: Elsevier BV
    Country: Canada

    Abstract Overproduction of the Nla X DNA methyltransferase (M· Nla X) in an Escherichia coli host conferred resistance to Sso II restriction endonuclease (R· Sso II) digestion. This suggested an overlap of sequence specificity between M· Nla X and M· Sso II, the latter of which modifies the internal cytosine of the target sequence 5′-CCNGG-3′. A variant of M· Nla X (M· Sso/Nla ), containing an N-terminal extension from M· Sso II, was also enzymatically active. Using deletion analysis, the N-terminal 71 amino-acid residues of M· Sso II were shown to be essential for modification activity.

  • Open Access
    Authors: 
    Yan Yang; Xing Chen; Young Soo Choi; Bo-Seon Kang;
    Publisher: Hindawi Limited

    1Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Ministry of Education, Chongqing 400054, China 2Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 3Department of Bioengineering, University of Washington, Seattle, WA 98195-5061, USA 4Department of Mechanical System Engineering, Chonnam National University, Gwangju 500757, Republic of Korea

  • Open Access
    Authors: 
    John Githaka Maringa; Anthony R. Vega; Michael W. Davidson; Khuloud Jaqaman; Nicolas Touret;
    Publisher: Elsevier BV

    CD36 is a multiligand scavenger receptor that ligates Thrombospondin-1 (TSP-1) at the surface of endothelial cells and induces their apoptosis. Recent evidences have shown that clustering of CD36 is necessary for signal transduction in macrophages and is regulated by the architecture of the cortical actin cytoskeleton apposed to the plasmalemma. Here, we investigated the role of the cortical actin cytoskeleton and plasma membrane nanodomains in the control of CD36 activation in endothelial cells. Stimulation with multivalent ligands (TSP-1 and anti-CD36 IgM) resulted in the downstream phosphorylation of the Src Family kinase, Fyn. Disruption of the actin cytoskeleton or removal of cholesterol blocked this activation. To gain molecular details on the rearrangement of the receptors during TSP-1 binding, we conducted superresolution approaches (based on PhotoActivated Localization Microscopy or PALM) and quantitative spatial distribution analysis. Endothelial cell lines stably expressing CD36-PAmCherry were generated for that purpose. At steady state, CD36 receptors pre-exist in small clusters (average diameter of 100 nm), in which Fyn was also present. Upon TSP-1 binding, CD36 clusters increased in size (average diameter of 140 nm) and also became denser. The average distance between CD36 molecules in these clusters was in the range of 8 nm compare to 11 nm in the control condition. F-actin depolymerization or cholesterol depletion reduced the capacity of the ligand to induce formation of larger clusters resulting in a decreased recruitment and activation of Fyn. Our data demonstrate cooperation between cholesterol-dependent domains and the cortical actin cytoskeleton in the organization of CD36 receptors and Fyn before and during TSP-1 stimulation.