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  • Open Access English
    Authors: 
    B. Sidda Reddy; J. Suresh Kumar; C. Eswara Reddy; K. Vijaya Kumar Reddy;
    Publisher: Hindawi Publishing Corporation

    The prime aim of the present study is to present analytical formulations and solutions for the buckling analysis of simply supported functionally graded plates (FGPs) using higher order shear deformation theory (HSDT) without enforcing zero transverse shear stresses on the top and bottom surfaces of the plate. It does not require shear correction factors and transverse shear stresses vary parabolically across the thickness. Material properties of the plate are assumed to vary in the thickness direction according to a power law distribution in terms of the volume fractions of the constituents. The equations of motion and boundary conditions are derived using the principle of virtual work. Solutions are obtained for FGPs in closed-form using Navier’s technique. Comparison studies are performed to verify the validity of the present results from which it can be concluded that the proposed theory is accurate and efficient in predicting the buckling behavior of functionally graded plates. The effect of side-to-thickness ratio, aspect ratio, modulus ratio, the volume fraction exponent, and the loading conditions on the critical buckling load of FGPs is also investigated and discussed.

  • Open Access English
    Authors: 
    Jonathan D. Midwood; Daniel Rokitnicki-Wojcik; Patricia Chow-Fraser;
    Publisher: International Scholarly Research Network
    Project: NSERC

    Coastal wetlands of eastern Georgian Bay provide critical habitat for a variety of wildlife, especially spawning and nursery habitat for Great Lakes fishes. Although the eastern shoreline has been designated a World Biosphere Reserve by UNESCO, a complete inventory is lacking. Prior effort by the Great Lakes Coastal Wetland Consortium (GLCWC) was unable to fully identify coastal wetland habitat in eastern Georgian Bay due to limited data coverage. Here we outline the methodology, analyses, and applications of the McMaster Coastal Wetland Inventory (MCWI) created from a comprehensive collection of satellite imagery from 2002–2008. Wetlands were manually delineated in a GIS as two broad habitat types: coastal marsh and upstream wetland. Coastal marsh was further subdivided into low marsh (LM; permanently inundated) and high marsh (HM; seasonally inundated) habitat. Within the coastal zone of eastern and northern Georgian Bay there are 12629 distinct wetland units comprised of 5376 ha of LM, 3298 ha of HM and 8676 ha of upstream habitat. The MCWI identifies greater total wetland area within the coastal zone than does the GLCWC inventory (17350 ha versus 3659 ha resp.). The MCWI provides the most current and comprehensive inventory of coastal wetlands in eastern Georgian Bay.

  • Open Access English
    Authors: 
    Sara Ansaloni; Brian P. Leung; Neeraj P. Sebastian; Rohini Samudralwar; Mariana C. Gadaleta; Aleister J. Saunders;
    Publisher: Hindawi Limited

    We report thatNTRK2, the gene encoding for the TrkB receptor, can regulate APP metabolism, specifically AICD levels. Using the human neuroblastoma cell line SH-SY5Y, we characterized the effect of three TrkB isoforms (FL, SHC, T) on APP metabolism by knockdown and overexpression. We found that TrkB FL increases AICD-mediated transcription and APP levels while it decreases sAPP levels. These effects were mainly mediated by the tyrosine kinase activity of the receptor and partially by the PLC-- and SHC-binding sites. The TrkB T truncated isoform did not have significant effects on APP metabolism when transfected by itself, while the TrkB SHC decreased AICD-mediated transcription. TrkB T abolished TrkB FL effects on APP metabolism when cotransfected with it while TrkB SHC cotransfected with TrkB FL still showed increased APP levels. In conclusion, we demonstrated that TrkB isoforms have differential effects on APP metabolism.

  • Open Access
    Authors: 
    Jeffrey M. Gimble; Bruce A. Bunnell; Louis Casteilla; Jin Sup Jung; Kotaro Yoshimura;
    Publisher: Hindawi Limited

    Mesenchymal progenitor/stromal/stem cell (MSC) research has made substantial progress during the past decades. Investigators have published a wealth of basic science and preclinical data documenting the potential utility, efficacy, and safety of MSCs. The majority of this work has focused on the bone marrow- or adipose-derived MSCs. Since this body of evidence has set the stage for clinicians to advance from the bench to the bedside, Stem Cells International set out to publish a special issue devoted to the topic of Phases I–III Clinical Trials Using Adult Stem Cells. The result is a collection of ten outstanding articles submitted by investigators representing ten countries across Asia, Europe, and North America. In all cases, the methods section of each manuscript included a statement documenting that the clinical investigations were performed following institutional review board approval and/or that patient informed consent had been provided prior to the conduct of the study. Bieback et al. in Germany (Translating research into clinical scale manufacturing of mesenchymal stromal cells) and B. Philippe et al. in France (in “Culture and Use of Mesenchymal Stromal Cells in Phase I and II Clinical Trials”) have focused on the process of MSC isolation and expansion with respect to current Good Manufacturing Practices (cGMP). These authors highlight the state of the art as well as the challenges facing the development of clinical grade cells for therapeutic applications. From a regulatory perspective, the simplest application of MSC is to use them in the context of their tissue of origin. S. Akita et al. in Japan (in “Noncultured Autologous Adipose-Derived Stem Cell Therapy for Chronic Radiation Injury”) have exploited adipose-derived stem cells for soft tissue regeneration. They describe their clinical experience using autologous adipose-derived stem cells in combination with growth factors and scaffold to treat ten patients suffering from dermal radiation lesions. A series of three review papers from Belgium (“Phase 1–3 Clinical Trials Using Adult Stem Cells in Osteonecrosis and Nonunion Fractures” by J. –P. Hauzeur and V. Gangji), the USA and China (“Mesenchymal Progenitor Cells and Their Orthopedic Applications: Forging a Path towards Clinical Trials” by D. S. Shenaq et al.), and the Netherlands (“Clinical Applications of Human Mesenchymal Stromal Cells for Bone Tissue Engineering” by Chatterjea et al.) have examined the use of bone marrow-derived MSC for orthopedic applications. Each work provides a unique perspective on the published clinical trials using MSC to treat cartilage and tendon repair, critical sized defects, metabolic bone diseases, nonunion fractures, and/or osteonecrosis. From a public health perspective, MSC applications for common cardiac and central nervous system disorders could have substantial health and societal benefits. R. Sanz-Ruiz et al. in Spain (in “Phases I–III Clinical Trials Using Adult Stem Cells”) have emphasized the critical importance of randomized clinical trials to assess the utility of MSCs as they focus on the clinical evidence supporting MSC-based treatment of cardiac disease. Furthermore, they review the guidance documents on future clinical trials provided by a task force convened by the European Society for Cardiology. P. A. Walker et al. in the USA (in “Progenitor Cell Therapy for The Treatment of Central Nervous System Injury: A Review of the State of Current Clinical Trials) provide a similar perspective relating to central nervous system disorders. They evaluate the use of bone marrow-derived MSCs for ischemic stroke, spinal cord injury, and traumatic brain injury and conclude that there remains a need for further evidence to support these clinical applications. There are potential MSC applications for metabolic disorders as well. A. C. Piscaglia et al. in Italy (in “Stem Cell Therapies for Liver Disease: State of the Art and New Perspectives) have reviewed the limited number of clinical trials using hematopoietic stem cell (HSC), MSC infusion, or cytokine (G-CSF) therapy to reverse hepatic injury due to cirrhosis, drug exposure, or other causes of end stage liver disease. Likewise, A. V. Vanikar et al. from India (in “Cotransplantation of Adipose Tissue-Derived Insulin Secreting Mesenchymal Stem Cells A Novel Therapy for Insulin-Dependent Diabetes Mellitus”) describe their experience combining adipose- and bone marrow-derived MSC to treat a cohort of 11 diabetic subjects for a period of up to 23 months. They report improved hemoglobin A1C levels as well as decreased daily requirements for exogenous insulin. Uniformly, these authors highlight both the promise and the challenges faced by this emerging field of medicine. Their manuscripts identify the critical need for additional prospective, randomized controlled clinical trials evaluating all cell-based therapies, regardless of the underlying disorder. In summary, this special issue provides a snapshot of the current status of MSC-based clinical trials across the globe. Hopefully, this publication will provide a benchmark for future meta-analyses evaluating a far greater body of clinical evidence regarding the safety and efficacy of MSC therapies. Jeffrey M. Gimble Bruce A. Bunnell Louis Casteilla Jin Sup Jung Kotaro Yoshimura

  • Open Access English
    Authors: 
    Christos M. Tsoukas; Louise Gilbert; Trevor Lewis; George Hatzakis; Ron Falcon; Joseph Mrus;
    Publisher: Hindawi Publishing Corporation

    Objective. During the course of HIV infection, progressive immune deficiency occurs. The aim of this prospective substudy was to evaluate the recovery of functional immunity in a subset of patients from the GRACE (Gender, Race, And Clinical Experience) study treated with a DRV/r-based regimen. Methods. The recovery of functional immunity with a darunavir/ritonavir-based regimen was assessed in a subset of treatment-experienced, HIV-1 infected patients from the GRACE study. Results. 19/32 patients (59%) enrolled in the substudy were virologically suppressed (<50 copies/mL). In these patients, median (range) CD4+ cell count increased from 222 (2, 398) cells/mm3 at baseline to 398 (119, 812) cells/mm3 at Week 48. CD8+% decreased significantly from baseline to Week 48 (P=.03). Proliferation of CD4+ lymphocytes in response to CD3+/CD28+, phytohemagglutinin, and pokeweed was significantly increased (P<.01) by Week 12. Proliferation in response to Candida and tetanus was significantly increased by Week 48 (P<.01 and P=.014, resp.). Staphylococcal enterotoxin B-stimulated tumor necrosis factor-alpha and interleukin-2 in CD4+ cells was significantly increased by Week 12 (P=.046) and Week 48 (P<.01), respectively. Conclusions. Darunavir/ritonavir-based therapy demonstrated improvements in CD4+ cell recovery and association with progressive functional immune recovery over 48 weeks. This trial is registered with NCT00381303.

  • Open Access English
    Authors: 
    Yongxia Zhou; Yvonne W. Lui;
    Publisher: Hindawi Publishing Corporation
    Project: CIHR , NIH | Alzheimers Disease Neuroi... (1U01AG024904-01), NIH | CORE-- CLINICAL (3P30AG010129-11S1), NIH | "MR Morphometrics and Cog... (5K01AG030514-02)

    Background. Small-world network consists of networks with local specialization and global integration. Our objective is to detect small-world properties alteration based on cortical thickness in mild cognitive impairment (MCI) including stables and converters, and early Alzheimer's disease (AD) compared to controls. Methods. MRI scans of 13 controls, 10 MCI, and 10 with early AD were retrospectively analyzed; 11 MCI converters, 11 MCI stables, and 10 controls from the ADNI website were also included. Results. There were significantly decreased local efficiencies in patients with MCI and AD compared to controls; and MCI patients showed increased global efficiency compared to AD and controls. The MCI converters experience the worst local efficiency during the converting period to AD; the stables, however, have highest local and global efficiency. Conclusions. The abnormal cortical thickness-based small-world properties in MCI and AD as well as the distinct patterns between two MCI subtypes suggest that small-world network analysis has the potential to better differentiate different stages of early dementia.

  • Open Access English
    Authors: 
    Leilani Feliciano; Jonathan C. Baker; Sarah L. Anderson; Linda A. LeBlanc; David M. Orchanian;
    Publisher: SAGE-Hindawi Access to Research

    Cognitive impairment represents a common mental health problem in community-dwelling and institutionalized older adults, and the prevalence increases with age. Multidisciplinary teams are often asked to assess cognitive and functional impairment in this population. The Cognitive Assessment of Minnesota was created by occupational therapists for this purpose and is frequently used, but has not been extensively validated. This study examined the performance of the CAM and compared it to the MMSE with 113 outpatient clinic patients over the age of 60. Subgroups were established based on scores on a depression inventory to determine if the presence of depressed mood altered the relationship between the measures. Both measures demonstrated good internal consistency. The overall correlation between the two measures was high, statistically significant and remained high regardless of depression status. We offer recommendations about the utility of each measure in screening cognitive functioning for older adults.

  • Open Access English
    Authors: 
    A. Michelle Lawing; Jesse M. Meik; P. David Polly;
    Publisher: International Scholarly Research Network

    We used ecological niche modelling to study the relative roles of climate and interspecific interactions in defining the parapatric contact between closely related species (Crotalus mitchellii and C. stephensi) and to predict refugia during the last glacial maximum. The modelled suitable habitat for C. stephensi correctly predicts the existing parapatric border between it and C. mitchellii, suggesting that C. stephensi's range at the border is limited by climatic factors. In contrast, the suitable habitat for C. mitchellii does not correctly predict the existing parapatric boundary; rather the suitable habitat of this species extends into the range of C. stephensi, suggesting the latter species, not climatic factors, limit the range of C. mitchellii. Modelled refugia of C. stephensi are much smaller than modern suitable habitat and are partially situated at the current parapatric border, whereas the refugia of C. mitchellii are similar to its current suitable habitat, though also shifted to the south. Ecological niche modelling appears to be a useful tool for studying the interplay between climate and competition in determining boundaries between parapatric species. It also appears to be useful for predicting past suitable habitats of species, because predicted refugia are congruent with independent estimates from molecular phylogeography.

  • Open Access
    Authors: 
    Sagar V. Krupa; M Nosal;
    Publisher: Hindawi Limited

    In ecological effects research, there is a rapid increase in the application of passive sampling techniques for measuring ambient ozone (O3) concentrations. Passive samplers provide data on cumulative exposures of a plant to a pollutant. However, O3is not an accumulative contaminant within the plant tissue, and use of prolonged passive sampling durations cannot account for the dynamics of the occurrences of O3that have a significant influence on the plant response. Therefore, a stochastic Weibull probability model was previously developed and applied to a site in Washington State (1650 m MSL) to simulate the cumulative exposure data from a passive sampler, to mimic the corresponding frequency distributions of hourly O3concentrations that would otherwise have been obtained by continuous monitoring. At that site the correlation between the actual passive sampler and the continuous monitor data was R2 = 0.74. The simulation of the hourly O3data was based on and compared with the results obtained from a colocated continuous monitor. In this paper we report the results of the model application to data from an unrelated monitoring site (New Hampshire, 476 m MSL) with poor correlation between the passive sampling and continuous monitoring (R2 = 0.24). In addition, as opposed to the previous work, we provide comparisons of the frequency distributions of the hourly O3concentrations obtained by the simulation and the actual continuous monitoring. In spite of the major difference in the R2 values, at both sites the simulation provided very satisfactory results within the 95% confidence interval, suggesting its broad applicability. The final objective of this overall approach is to develop a generic model that can simulate reasonably well the occurrences of ambient O3concentrations that are dependent upon the elevation of the measurement site and the synoptic and local meteorology. Such an effort would extend the relative utility of the passive sampling data in explaining stochastic plant responses.

  • Open Access English
    Authors: 
    Christopher J. Grassa; Rob J. Kulathinal;
    Publisher: SAGE-Hindawi Access to Research

    Among closely related taxa, proteins involved in reproduction generally evolve more rapidly than other proteins. Here, we apply a functional and comparative genomics approach to compare functional divergence across a deep phylogenetic array of egg-laying and live-bearing vertebrate taxa. We aligned and annotated a set of 4,986 1 : 1 : 1 : 1 : 1 orthologs inAnolis carolinensis(green lizard),Danio rerio(zebrafish),Xenopus tropicalis(frog),Gallus gallus(chicken), andMus musculus(mouse) according to function using ESTs from available reproductive (including testis and ovary) and non-reproductive tissues as well as Gene Ontology. For each species lineage, genes were further classified as tissue-specific (found in a single tissue) or tissue-expressed (found in multiple tissues). Within independent vertebrate lineages, we generally find that gonadal-specific genes evolve at a faster rate than gonadal-expressed genes and significantly faster than non-reproductive genes. Among the gonadal set, testis genes are generally more diverged than ovary genes. Surprisingly, an opposite but nonsignificant pattern is found among the subset of orthologs that remained functionally conserved acrossallfive lineages. These contrasting evolutionary patterns found between functionally diverged and functionally conserved reproductive orthologs provide evidence for pervasive and potentially cryptic lineage-specific selective processes on ancestral reproductive systems in vertebrates.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
81 Research products, page 1 of 9
  • Open Access English
    Authors: 
    B. Sidda Reddy; J. Suresh Kumar; C. Eswara Reddy; K. Vijaya Kumar Reddy;
    Publisher: Hindawi Publishing Corporation

    The prime aim of the present study is to present analytical formulations and solutions for the buckling analysis of simply supported functionally graded plates (FGPs) using higher order shear deformation theory (HSDT) without enforcing zero transverse shear stresses on the top and bottom surfaces of the plate. It does not require shear correction factors and transverse shear stresses vary parabolically across the thickness. Material properties of the plate are assumed to vary in the thickness direction according to a power law distribution in terms of the volume fractions of the constituents. The equations of motion and boundary conditions are derived using the principle of virtual work. Solutions are obtained for FGPs in closed-form using Navier’s technique. Comparison studies are performed to verify the validity of the present results from which it can be concluded that the proposed theory is accurate and efficient in predicting the buckling behavior of functionally graded plates. The effect of side-to-thickness ratio, aspect ratio, modulus ratio, the volume fraction exponent, and the loading conditions on the critical buckling load of FGPs is also investigated and discussed.

  • Open Access English
    Authors: 
    Jonathan D. Midwood; Daniel Rokitnicki-Wojcik; Patricia Chow-Fraser;
    Publisher: International Scholarly Research Network
    Project: NSERC

    Coastal wetlands of eastern Georgian Bay provide critical habitat for a variety of wildlife, especially spawning and nursery habitat for Great Lakes fishes. Although the eastern shoreline has been designated a World Biosphere Reserve by UNESCO, a complete inventory is lacking. Prior effort by the Great Lakes Coastal Wetland Consortium (GLCWC) was unable to fully identify coastal wetland habitat in eastern Georgian Bay due to limited data coverage. Here we outline the methodology, analyses, and applications of the McMaster Coastal Wetland Inventory (MCWI) created from a comprehensive collection of satellite imagery from 2002–2008. Wetlands were manually delineated in a GIS as two broad habitat types: coastal marsh and upstream wetland. Coastal marsh was further subdivided into low marsh (LM; permanently inundated) and high marsh (HM; seasonally inundated) habitat. Within the coastal zone of eastern and northern Georgian Bay there are 12629 distinct wetland units comprised of 5376 ha of LM, 3298 ha of HM and 8676 ha of upstream habitat. The MCWI identifies greater total wetland area within the coastal zone than does the GLCWC inventory (17350 ha versus 3659 ha resp.). The MCWI provides the most current and comprehensive inventory of coastal wetlands in eastern Georgian Bay.

  • Open Access English
    Authors: 
    Sara Ansaloni; Brian P. Leung; Neeraj P. Sebastian; Rohini Samudralwar; Mariana C. Gadaleta; Aleister J. Saunders;
    Publisher: Hindawi Limited

    We report thatNTRK2, the gene encoding for the TrkB receptor, can regulate APP metabolism, specifically AICD levels. Using the human neuroblastoma cell line SH-SY5Y, we characterized the effect of three TrkB isoforms (FL, SHC, T) on APP metabolism by knockdown and overexpression. We found that TrkB FL increases AICD-mediated transcription and APP levels while it decreases sAPP levels. These effects were mainly mediated by the tyrosine kinase activity of the receptor and partially by the PLC-- and SHC-binding sites. The TrkB T truncated isoform did not have significant effects on APP metabolism when transfected by itself, while the TrkB SHC decreased AICD-mediated transcription. TrkB T abolished TrkB FL effects on APP metabolism when cotransfected with it while TrkB SHC cotransfected with TrkB FL still showed increased APP levels. In conclusion, we demonstrated that TrkB isoforms have differential effects on APP metabolism.

  • Open Access
    Authors: 
    Jeffrey M. Gimble; Bruce A. Bunnell; Louis Casteilla; Jin Sup Jung; Kotaro Yoshimura;
    Publisher: Hindawi Limited

    Mesenchymal progenitor/stromal/stem cell (MSC) research has made substantial progress during the past decades. Investigators have published a wealth of basic science and preclinical data documenting the potential utility, efficacy, and safety of MSCs. The majority of this work has focused on the bone marrow- or adipose-derived MSCs. Since this body of evidence has set the stage for clinicians to advance from the bench to the bedside, Stem Cells International set out to publish a special issue devoted to the topic of Phases I–III Clinical Trials Using Adult Stem Cells. The result is a collection of ten outstanding articles submitted by investigators representing ten countries across Asia, Europe, and North America. In all cases, the methods section of each manuscript included a statement documenting that the clinical investigations were performed following institutional review board approval and/or that patient informed consent had been provided prior to the conduct of the study. Bieback et al. in Germany (Translating research into clinical scale manufacturing of mesenchymal stromal cells) and B. Philippe et al. in France (in “Culture and Use of Mesenchymal Stromal Cells in Phase I and II Clinical Trials”) have focused on the process of MSC isolation and expansion with respect to current Good Manufacturing Practices (cGMP). These authors highlight the state of the art as well as the challenges facing the development of clinical grade cells for therapeutic applications. From a regulatory perspective, the simplest application of MSC is to use them in the context of their tissue of origin. S. Akita et al. in Japan (in “Noncultured Autologous Adipose-Derived Stem Cell Therapy for Chronic Radiation Injury”) have exploited adipose-derived stem cells for soft tissue regeneration. They describe their clinical experience using autologous adipose-derived stem cells in combination with growth factors and scaffold to treat ten patients suffering from dermal radiation lesions. A series of three review papers from Belgium (“Phase 1–3 Clinical Trials Using Adult Stem Cells in Osteonecrosis and Nonunion Fractures” by J. –P. Hauzeur and V. Gangji), the USA and China (“Mesenchymal Progenitor Cells and Their Orthopedic Applications: Forging a Path towards Clinical Trials” by D. S. Shenaq et al.), and the Netherlands (“Clinical Applications of Human Mesenchymal Stromal Cells for Bone Tissue Engineering” by Chatterjea et al.) have examined the use of bone marrow-derived MSC for orthopedic applications. Each work provides a unique perspective on the published clinical trials using MSC to treat cartilage and tendon repair, critical sized defects, metabolic bone diseases, nonunion fractures, and/or osteonecrosis. From a public health perspective, MSC applications for common cardiac and central nervous system disorders could have substantial health and societal benefits. R. Sanz-Ruiz et al. in Spain (in “Phases I–III Clinical Trials Using Adult Stem Cells”) have emphasized the critical importance of randomized clinical trials to assess the utility of MSCs as they focus on the clinical evidence supporting MSC-based treatment of cardiac disease. Furthermore, they review the guidance documents on future clinical trials provided by a task force convened by the European Society for Cardiology. P. A. Walker et al. in the USA (in “Progenitor Cell Therapy for The Treatment of Central Nervous System Injury: A Review of the State of Current Clinical Trials) provide a similar perspective relating to central nervous system disorders. They evaluate the use of bone marrow-derived MSCs for ischemic stroke, spinal cord injury, and traumatic brain injury and conclude that there remains a need for further evidence to support these clinical applications. There are potential MSC applications for metabolic disorders as well. A. C. Piscaglia et al. in Italy (in “Stem Cell Therapies for Liver Disease: State of the Art and New Perspectives) have reviewed the limited number of clinical trials using hematopoietic stem cell (HSC), MSC infusion, or cytokine (G-CSF) therapy to reverse hepatic injury due to cirrhosis, drug exposure, or other causes of end stage liver disease. Likewise, A. V. Vanikar et al. from India (in “Cotransplantation of Adipose Tissue-Derived Insulin Secreting Mesenchymal Stem Cells A Novel Therapy for Insulin-Dependent Diabetes Mellitus”) describe their experience combining adipose- and bone marrow-derived MSC to treat a cohort of 11 diabetic subjects for a period of up to 23 months. They report improved hemoglobin A1C levels as well as decreased daily requirements for exogenous insulin. Uniformly, these authors highlight both the promise and the challenges faced by this emerging field of medicine. Their manuscripts identify the critical need for additional prospective, randomized controlled clinical trials evaluating all cell-based therapies, regardless of the underlying disorder. In summary, this special issue provides a snapshot of the current status of MSC-based clinical trials across the globe. Hopefully, this publication will provide a benchmark for future meta-analyses evaluating a far greater body of clinical evidence regarding the safety and efficacy of MSC therapies. Jeffrey M. Gimble Bruce A. Bunnell Louis Casteilla Jin Sup Jung Kotaro Yoshimura

  • Open Access English
    Authors: 
    Christos M. Tsoukas; Louise Gilbert; Trevor Lewis; George Hatzakis; Ron Falcon; Joseph Mrus;
    Publisher: Hindawi Publishing Corporation

    Objective. During the course of HIV infection, progressive immune deficiency occurs. The aim of this prospective substudy was to evaluate the recovery of functional immunity in a subset of patients from the GRACE (Gender, Race, And Clinical Experience) study treated with a DRV/r-based regimen. Methods. The recovery of functional immunity with a darunavir/ritonavir-based regimen was assessed in a subset of treatment-experienced, HIV-1 infected patients from the GRACE study. Results. 19/32 patients (59%) enrolled in the substudy were virologically suppressed (<50 copies/mL). In these patients, median (range) CD4+ cell count increased from 222 (2, 398) cells/mm3 at baseline to 398 (119, 812) cells/mm3 at Week 48. CD8+% decreased significantly from baseline to Week 48 (P=.03). Proliferation of CD4+ lymphocytes in response to CD3+/CD28+, phytohemagglutinin, and pokeweed was significantly increased (P<.01) by Week 12. Proliferation in response to Candida and tetanus was significantly increased by Week 48 (P<.01 and P=.014, resp.). Staphylococcal enterotoxin B-stimulated tumor necrosis factor-alpha and interleukin-2 in CD4+ cells was significantly increased by Week 12 (P=.046) and Week 48 (P<.01), respectively. Conclusions. Darunavir/ritonavir-based therapy demonstrated improvements in CD4+ cell recovery and association with progressive functional immune recovery over 48 weeks. This trial is registered with NCT00381303.

  • Open Access English
    Authors: 
    Yongxia Zhou; Yvonne W. Lui;
    Publisher: Hindawi Publishing Corporation
    Project: CIHR , NIH | Alzheimers Disease Neuroi... (1U01AG024904-01), NIH | CORE-- CLINICAL (3P30AG010129-11S1), NIH | "MR Morphometrics and Cog... (5K01AG030514-02)

    Background. Small-world network consists of networks with local specialization and global integration. Our objective is to detect small-world properties alteration based on cortical thickness in mild cognitive impairment (MCI) including stables and converters, and early Alzheimer's disease (AD) compared to controls. Methods. MRI scans of 13 controls, 10 MCI, and 10 with early AD were retrospectively analyzed; 11 MCI converters, 11 MCI stables, and 10 controls from the ADNI website were also included. Results. There were significantly decreased local efficiencies in patients with MCI and AD compared to controls; and MCI patients showed increased global efficiency compared to AD and controls. The MCI converters experience the worst local efficiency during the converting period to AD; the stables, however, have highest local and global efficiency. Conclusions. The abnormal cortical thickness-based small-world properties in MCI and AD as well as the distinct patterns between two MCI subtypes suggest that small-world network analysis has the potential to better differentiate different stages of early dementia.

  • Open Access English
    Authors: 
    Leilani Feliciano; Jonathan C. Baker; Sarah L. Anderson; Linda A. LeBlanc; David M. Orchanian;
    Publisher: SAGE-Hindawi Access to Research

    Cognitive impairment represents a common mental health problem in community-dwelling and institutionalized older adults, and the prevalence increases with age. Multidisciplinary teams are often asked to assess cognitive and functional impairment in this population. The Cognitive Assessment of Minnesota was created by occupational therapists for this purpose and is frequently used, but has not been extensively validated. This study examined the performance of the CAM and compared it to the MMSE with 113 outpatient clinic patients over the age of 60. Subgroups were established based on scores on a depression inventory to determine if the presence of depressed mood altered the relationship between the measures. Both measures demonstrated good internal consistency. The overall correlation between the two measures was high, statistically significant and remained high regardless of depression status. We offer recommendations about the utility of each measure in screening cognitive functioning for older adults.

  • Open Access English
    Authors: 
    A. Michelle Lawing; Jesse M. Meik; P. David Polly;
    Publisher: International Scholarly Research Network

    We used ecological niche modelling to study the relative roles of climate and interspecific interactions in defining the parapatric contact between closely related species (Crotalus mitchellii and C. stephensi) and to predict refugia during the last glacial maximum. The modelled suitable habitat for C. stephensi correctly predicts the existing parapatric border between it and C. mitchellii, suggesting that C. stephensi's range at the border is limited by climatic factors. In contrast, the suitable habitat for C. mitchellii does not correctly predict the existing parapatric boundary; rather the suitable habitat of this species extends into the range of C. stephensi, suggesting the latter species, not climatic factors, limit the range of C. mitchellii. Modelled refugia of C. stephensi are much smaller than modern suitable habitat and are partially situated at the current parapatric border, whereas the refugia of C. mitchellii are similar to its current suitable habitat, though also shifted to the south. Ecological niche modelling appears to be a useful tool for studying the interplay between climate and competition in determining boundaries between parapatric species. It also appears to be useful for predicting past suitable habitats of species, because predicted refugia are congruent with independent estimates from molecular phylogeography.

  • Open Access
    Authors: 
    Sagar V. Krupa; M Nosal;
    Publisher: Hindawi Limited

    In ecological effects research, there is a rapid increase in the application of passive sampling techniques for measuring ambient ozone (O3) concentrations. Passive samplers provide data on cumulative exposures of a plant to a pollutant. However, O3is not an accumulative contaminant within the plant tissue, and use of prolonged passive sampling durations cannot account for the dynamics of the occurrences of O3that have a significant influence on the plant response. Therefore, a stochastic Weibull probability model was previously developed and applied to a site in Washington State (1650 m MSL) to simulate the cumulative exposure data from a passive sampler, to mimic the corresponding frequency distributions of hourly O3concentrations that would otherwise have been obtained by continuous monitoring. At that site the correlation between the actual passive sampler and the continuous monitor data was R2 = 0.74. The simulation of the hourly O3data was based on and compared with the results obtained from a colocated continuous monitor. In this paper we report the results of the model application to data from an unrelated monitoring site (New Hampshire, 476 m MSL) with poor correlation between the passive sampling and continuous monitoring (R2 = 0.24). In addition, as opposed to the previous work, we provide comparisons of the frequency distributions of the hourly O3concentrations obtained by the simulation and the actual continuous monitoring. In spite of the major difference in the R2 values, at both sites the simulation provided very satisfactory results within the 95% confidence interval, suggesting its broad applicability. The final objective of this overall approach is to develop a generic model that can simulate reasonably well the occurrences of ambient O3concentrations that are dependent upon the elevation of the measurement site and the synoptic and local meteorology. Such an effort would extend the relative utility of the passive sampling data in explaining stochastic plant responses.

  • Open Access English
    Authors: 
    Christopher J. Grassa; Rob J. Kulathinal;
    Publisher: SAGE-Hindawi Access to Research

    Among closely related taxa, proteins involved in reproduction generally evolve more rapidly than other proteins. Here, we apply a functional and comparative genomics approach to compare functional divergence across a deep phylogenetic array of egg-laying and live-bearing vertebrate taxa. We aligned and annotated a set of 4,986 1 : 1 : 1 : 1 : 1 orthologs inAnolis carolinensis(green lizard),Danio rerio(zebrafish),Xenopus tropicalis(frog),Gallus gallus(chicken), andMus musculus(mouse) according to function using ESTs from available reproductive (including testis and ovary) and non-reproductive tissues as well as Gene Ontology. For each species lineage, genes were further classified as tissue-specific (found in a single tissue) or tissue-expressed (found in multiple tissues). Within independent vertebrate lineages, we generally find that gonadal-specific genes evolve at a faster rate than gonadal-expressed genes and significantly faster than non-reproductive genes. Among the gonadal set, testis genes are generally more diverged than ovary genes. Surprisingly, an opposite but nonsignificant pattern is found among the subset of orthologs that remained functionally conserved acrossallfive lineages. These contrasting evolutionary patterns found between functionally diverged and functionally conserved reproductive orthologs provide evidence for pervasive and potentially cryptic lineage-specific selective processes on ancestral reproductive systems in vertebrates.