Towards the Exploration of Task and Workflow Scheduling Methods and Mechanisms in Cloud Computing Environment

Cloud computing sets a domain and application-specific distributed environment to distribute the services and resources among users. There are numerous heterogeneous VMs available in the environment to handle user requests. The user requests are defined with a specific deadline. The scheduling methods are defined to set up the order of request execution in the cloud environment. The scheduling methods in a cloud environment are divided into two main categories called Task and Workflow Scheduling. This paper, is a study of work performed on task and workflow scheduling. Various feature processing, constraints-restricted, and priority-driven methods are discussed in this research. The paper also discussed various optimization methods to improve scheduling performance and reliability in the cloud environment. Various constraints and performance parameters are discussed in this research

UV-screening and springtime recovery of photosynthetic capacity in leaves of Vaccinium vitis-idaea above and below the snow pack

Evergreen plants in boreal biomes undergo seasonal hardening and dehardening adjusting their photosynthetic capacity and photopmtection; acclimating to seasonal changes in temperature and irradiance. Leaf epidermal ultraviolet (UV)-screening by flavonols responds to solar radiation, perceived in part through increased ultraviolet-B (UV-B) radiation, and is a candidate trait to provide cross-photoprotection. At Hyytiala Forestry Station, central Finland, we examined whether the accumulation of flavonols was higher in leaves of Vaccinium vitis-idaea L. growing above the snowpack compared with those below the snowpack. We found that leaves exposed to colder temperatures and higher solar radiation towards the top of hummocks suffered greater photoinhibition than those at the base of hummocks. Epidermal UV-screening was highest in upper-hummock leaves, particularly during winter when lower leaves were beneath the snowpack. There was also a negative relationship between indices of flavonols and anthocyanins across all leaves suggesting fine-tuning of flavonoid composition for screening vs. antioxidant activity in response to temperature and irradiance. However, the positive correlation between the maximum quantum yield of photosystem II photochemistry (F-v/F-m) and flavonol accumulation in upper hummock leaves during dehardening did not confer on them any greater cross-protection than would be expected from the general relationship of F-v/F-m with temperature and irradiance (throughout the hummocks). Irrespective of timing of snow-melt, photosynthesis fully recovered in all leaves, suggesting that V. vills-idaea has the potential to exploit the continuing trend for longer growing seasons in central Finland without incurring significant impairment from reduced duration of snow cover.Peer reviewe

Cobalt containing glass fibres and their synergistic effect on the HIF-1 pathway for wound healing applications

Introduction and Methods: Chronic wounds are a major healthcare problem, but their healing may be improved by developing biomaterials which can stimulate angiogenesis, e.g. by activating the Hypoxia Inducible Factor (HIF) pathway. Here, novel glass fibres were produced by laser spinning. The hypothesis was that silicate glass fibres that deliver cobalt ions will activate the HIF pathway and promote the expression of angiogenic genes. The glass composition was designed to biodegrade and release ions, but not form a hydroxyapatite layer in body fluid. Results and Discussion: Dissolution studies demonstrated that hydroxyapatite did not form. When keratinocyte cells were exposed to conditioned media from the cobalt-containing glass fibres, significantly higher amounts of HIF-1α and Vascular Endothelial Growth Factor (VEGF) were measured compared to when the cells were exposed to media with equivalent amounts of cobalt chloride. This was attributed to a synergistic effect of the combination of cobalt and other therapeutic ions released from the glass. The effect was also much greater than the sum of HIF-1α and VEGF expression when the cells were cultured with cobalt ions and with dissolution products from the Co-free glass, and was proven to not be due to a rise in pH. The ability of the glass fibres to activate the HIF-1 pathway and promote VEGF expression shows the potential for their use in chronic wound dressings.National Institute for Health Research (Reino Unido) | Ref. II-ES-1010-10094Agencia Estatal de Investigación | Ref. PID2020-117900RB-I0

Hyaluronic acid hydrogels reinforced with laser spun bioactive glass micro- and nanofibres doped with lithium

The repair of articular cartilage lesions in weight-bearing joints remains as a significant challenge due to the low regenerative capacity of this tissue. Hydrogels are candidates to repair lesions as they have similar properties to cartilage extracellular matrix but they are unable to meet the mechanical and biological requirements for a successful outcome. Here, we reinforce hyaluronic acid (HA) hydrogels with 13-93-lithium bioactive glass micro- and nanofibres produced by laser spinning. The glass fibres are a reinforcement filler and a platform for the delivery of therapeutic lithium-ions. The elastic modulus of the composites is more than three times higher than in HA hydrogels. Modelling of the reinforcement corroborates the experimental results. ATDC5 chondrogenic cells seeded on the composites are viable and more proliferation occurs on the hydrogels containing fibres than in HA hydrogels alone. Furthermore, the chondrogenic behavior on HA constructs with fibres containing lithium is more marked than in hydrogels with no-lithium fibres.Xunta de Galicia | Ref. ED431B 2016/042Xunta de Galicia | Ref. POS-A/2013/161Xunta de Galicia | Ref. ED481D 2017/010Xunta de Galicia | Ref. ED481B 2016/047-

Highly degradable porous melt-derived bioactive glass foam scaffolds for bone regeneration

A challenge in using bioactive melt-derived glass in bone regeneration is to produce scaffolds with interconnected pores while maintaining the amorphous nature of the glass and its associated bioactivity. Here we introduce a method for creating porous melt-derived bioactive glass foam scaffolds with low silica content and report in vitro and preliminary in vivo data. The gel-cast foaming process was adapted, employing temperature controlled gelation of gelatin, rather than the in situ acrylic polymerisation used previously. To form a 3D construct from melt derived glasses, particles must be fused via thermal processing, termed sintering. The original Bioglass® 45S5 composition crystallises upon sintering, altering its bioactivity, due to the temperature difference between the glass transition temperature and the crystallisation onset being small. Here, we optimised and compared scaffolds from three glass compositions, ICIE16, PSrBG and 13–93, which were selected due to their widened sintering windows. Amorphous scaffolds with modal pore interconnect diameters between 100–150 µm and porosities of 75% had compressive strengths of 3.4 ± 0.3 MPa, 8.4 ± 0.8 MPa and 15.3 ± 1.8 MPa, for ICIE16, PSrBG and 13–93 respectively. These porosities and compressive strength values are within the range of cancellous bone, and greater than previously reported foamed scaffolds. Dental pulp stem cells attached to the scaffold surfaces during in vitro culture and were viable. In vivo, the scaffolds were found to regenerate bone in a rabbit model according to X-ray micro tomography imaging

Development of cobalt bioactive glasses for wound healing applications

Bioactive glasses are of interest in regenerative medicine as they can incorporate ions beneficial for tissue repair and release these into aqueous environments as the glass degrades. To date, bioactive glasses have been primarily used for bone regeneration, however they have also shown promise in soft tissue applications, such as wound healing. When a wound forms, a cascade of events occur to repair the damaged skin. If healing is impaired, for example in diabetic patients, a chronic wound can form, which does not heal in a predictable manner. The Hypoxia Inducible Factor (HIF) pathway regulates the expression of genes involved in adaption to hypoxia, such as those involved in angiogenesis, and local activation of this pathway can promote the healing of diabetic wounds. Cobalt is known to activate the HIF pathway, and in this thesis, cobalt bioactive glasses were investigated for the first time in wound healing applications. New melt-derived glass compositions were designed, which could degrade and release cobalt ions in aqueous environments, without the formation of crystalline hydroxycarbonate apatite. Glass particles are not suitable for direct application to a wound bed, and therefore the designed glasses were developed into composites by electrospinning, and into fibres by laser spinning. These formats were able to release cobalt ions and activate the HIF pathway in vitro, causing a functional response measured by an increased expression of Vascular Endothelial Growth Factor (VEGF). By comparing a single composition with and without cobalt, it was shown that the cobalt bioactive glass fibres caused a synergistic effect on HIF-1α stabilisation and VEGF expression, which could not be replicated by supplementing cell culture media with cobalt. Overall the work presented in this thesis shows the potential for the designed cobalt bioactive glass compositions and formats to be used to promote the healing of chronic wounds.Open Acces

Comparative Study of Complement Biomarkers in Schizophrenic Patients

Introduction: Dysregulation of the complement system in schizophrenia with increased activation of the classical complement pathway has been observer earlier. The present study was undertaken to find out the effects of dysregulation of complement factors in schizophrenic patients, for confirmation and making an early diagnosis for high-risk patients by analysing of the complement factors. Methodology: All patients aged 18-65 years who presented with schizophrenia were enrolled. A total of 80 blood samples were collected from three study groups. Diagnosis was made using the ICD-10 criteria for schizophrenia. Participants fulfilling the inclusion criteria of ability to understand the nature of test and being drug naïve and willing to participate in the study were recruited after written consents from participants and their first degree relatives at Psychiatric Centre, SMS Medical College, Jaipur, Rajasthan (India). Results: This study observed a significantly lower mean value of C4 and CR1 in schizophrenic patients than control and significant dysregulation of various complement factors was seen with respect to certain sociodemographic profile. No significant dysregulation was observed in first degree relatives. Conclusion: The role of complement dysregulation in etio pathogenesis was found in the present study. This could be helpful in early diagnosis and identification of individuals at high risk of developing schizophrenia

Data for accelerated degradation of calcium phosphate surface-coated polycaprolactone and polycaprolactone/bioactive glass composite scaffolds

Polycaprolactone (PCL)-based composite scaffolds containing 50 wt% of 45S5 bioactive glass (45S5) or strontium-substituted bioactive glass (SrBG) particles were fabricated into scaffolds using melt-extrusion based additive manufacturing technique. Additionally, the PCL scaffolds were surface coated with a layer of calcium phosphate (CaP). For a comparison of the scaffold degradation, the scaffolds were then subjected to in vitro accelerated degradation by immersion in 5 M sodium hydroxide (NaOH) solution for up to 7 days. The scaffold׳s morphology was observed by means of SEM imaging and scaffold mass loss was recorded over the experimental period

Rheological characterization of biomaterials directs additive manufacturing of strontium-substituted bioactive glass/polycaprolactone microfibers

Additive manufacturing via melt electrowriting (MEW) can create ordered microfiber scaffolds relevant for bone tissue engineering; however, there remain limitations in the adoption of new printing materials, especially in MEW of biomaterials. For example, while promising composite formulations of polycaprolactone with strontium-substituted bioactive glass have been processed into large or disordered fibres, from what is known, biologically-relevant concentrations (>10 wt%) have never been printed into ordered microfibers using MEW. In this study, rheological characterization is used in combination with a predictive mathematical model to optimize biomaterial formulations and MEW conditions required to extrude various PCL and PCL/SrBG biomaterials to create ordered scaffolds. Previously, MEW printing of PCL/SrBG composites with 33 wt% glass required unachievable extrusion pressures. The composite formulation is modified using an evaporable solvent to reduce viscosity 100-fold to fall within the predicted MEW pressure, temperature, and voltage tolerances, which enabled printing. This study reports the first fabrication of reproducible, ordered high-content bioactive glass microfiber scaffolds by applying predictive modeling.</p