189 research outputs found

    Rangelands Vegetation Mapping at Species Composition Level Using the \u3cb\u3eSPiCla\u3c/b\u3e Method: \u3cb\u3eS\u3c/b\u3eDM Based \u3cb\u3ePi\u3c/b\u3exel \u3cb\u3eCla\u3c/b\u3essification and Fuzzy Accuracy. A New Approach of Map Making

    Get PDF
    Vegetation maps have been made since centuries. The vegetation cover was represented as homogeneous mapping units (polygons), representing different vegetation types, where each type consists a combination of different plant species (floristic composition). More recent, with the use of satellite imagery, the polygons have been replaced by pixels with similar content as the polygon maps. In both approaches, field-observations were linked to the mapping units (polygons or pixels) often resulting in a complex of different vegetation types per mapping unit. In our new approach field data (sample points) on presence and abundance of individual grass species are spatially extrapolated based on a set of environmental layers, using the species distribution modelling approach (SDM). When combined, each pixel will contain its own set of information about the vegetation structure and its floristic composition. This new methodology (SPiCla) results in a very accurate and detailed vegetation map at pixel level, allowing extraction of very detailed, accurate and easy to update spatial information on e.g., forage production and quality (palatability) for rangelands management. As no exact boundaries exist, but only gradients, we introduced fuzzy accuracy. The resolution mainly depends on the resolution of (or one of) the environmental layers used, scale of interest and workability. The methodology is generic and applicable to any other region in the world

    MARIS: Scalable Online Scenario Development Tool for Rangeland Conservancy Managers Using High Spatial-Temporal Resolution Carrying Capacity Maps and Livestock Market Data

    Get PDF
    Although the management of livestock numbers within the bounds of carrying capacity of African rangelands is a way to manage risks, both scientists and practitioners, caution against a momentary and local use of carrying capacity as a management indicator. Carrying capacity should be seen in wider spatial and temporal/seasonal context as well as in a social and economic context. Given the large numbers of conservancies across Kenya, and its Maasai Mara region in particular, with many more landowner members, it is difficult for conservancies’ managers to contextualize phenomena such as carrying capacity and market price over space and time. We report the results of an investigation in the Maasai Mara rangelands, into functional characteristics a tool for spatial-temporal carrying capacity assessment and livestock markets prices monitoring should have to provide relevant management information to conservancy managers and conservancy members. A scalable web-application called the Mara Rangeland Information System, or MARIS, was developed, which assesses, at 23 meter resolution and 10 day historic or 1-day near-future intervals, both grassland dry matter production, and consumption by 19 wildlife and livestock species, as well as rangeland carrying capacity. MARIS facilitates managers to develop scenarios by varying input variables of either grass production or consumption, or by drawing different management blocks on a carrying capacity map assessing different management practices under scenarios of rainfall. Managers can relate the carrying capacity scenarios to offtake prices at different markets that MARIS monitors over time. After testing MARIS in 6 workshop iterations across the whole development process, Maasai Mara rangeland managers concluded that the prototype is ready for pilot use in management plan development

    Fatigue is Associated with Reduced Participation and Health-related Quality of Life Five Years After Perimesencephalic Subarachnoid Haemorrhage:A Multicentre Cross-sectional Study

    Get PDF
    OBJECTIVE: To determine whether fatigue is associated with participation and health-related quality of life 5 years after perimesencephalic subarachnoid haemorrhage. DESIGN: Multicentre cross-sectional study. SUBJECTS: Forty-six patients with perimesencephalic subarachnoid haemorrhage. METHODS: Fatigue was assessed with the Fatigue Severity Scale, participation (frequency, restrictions, satisfaction) with the Utrecht Scale for Evaluation of Rehabilitation-Participation, health-related quality of life with the Stroke-Specific Quality of Life Scale-12, symptoms of depression and anxiety with the Hospital Anxiety and Depression Scale, and coping with the Coping Inventory for Stressful Situations. RESULTS: A total of 46 patients were included (63% men, mean age 50.4 ± 9.4 years), with a mean time of 4.7 ± 1.6 years after perimesencephalic subarachnoid haemorrhage onset. Fatigued patients (33%) had worse participation (p < 0.01) and health-related quality of life (p < 0.001) than non-fatigued patients, and more often had hypertension, depression, anxiety and emotion-oriented coping (p < 0.05). Fatigue severity was inversely and independently (p < 0.005) associated with participation frequency (B = –3.62), satisfaction (B = –4.54), having restrictions (odds ratio = 2.48, 95% confidence interval 1.079–5.685), and health-related quality of life (B = –0.19), adjusted for depression, anxiety, and/or hypertension. CONCLUSION: Five years after perimesencephalic subarachnoid haemorrhage, one-third of patients still reported fatigue, which was associated with worse participation and health-related quality of life. Future studies should examine whether these patients may benefit from rehabilitation aimed at fatigue. LAY ABSTRACT A subarachnoid haemorrhage (SAH) is a subtype of stroke. Of all patients with SAH, approximately 10% are diagnosed with non-aneurysmal perimesencephalic subarachnoid haemorrhage (PM-SAH). PM-SAH is generally considered a benign form of SAH; however we have previously found that one-third of patients with PM-SAH are still fatigued 5 years after PM-SAH. Fatigue may be related to reduced participation and health-related quality of life, both of which are considered important rehabilitation outcomes. Therefore, this study examined whether fatigue is associated with participation and health-related quality of life after PM-SAH. The results showed that, 5 years after PM-SAH, fatigued patients had worse participation and quality of life than non-fatigued patients. In addition, more severe fatigue was associated with worse participation, regarding frequency, satisfaction and restrictions, and with worse health-related quality of life. Further studies are necessary to determine whether patients with PM-SAH may benefit from rehabilitation aimed at fatigue

    Effect of Strain Magnitude on the Tissue Properties of Engineered Cardiovascular Constructs

    Get PDF
    Mechanical loading is a powerful regulator of tissue properties in engineered cardiovascular tissues. To ultimately regulate the biochemical processes, it is essential to quantify the effect of mechanical loading on the properties of engineered cardiovascular constructs. In this study the Flexercell FX-4000T (Flexcell Int. Corp., USA) straining system was modified to simultaneously apply various strain magnitudes to individual samples during one experiment. In addition, porous polyglycolic acid (PGA) scaffolds, coated with poly-4-hydroxybutyrate (P4HB), were partially embedded in a silicone layer to allow long-term uniaxial cyclic mechanical straining of cardiovascular engineered constructs. The constructs were subjected to two different strain magnitudes and showed differences in biochemical properties, mechanical properties and organization of the microstructure compared to the unstrained constructs. The results suggest that when the tissues are exposed to prolonged mechanical stimulation, the production of collagen with a higher fraction of crosslinks is induced. However, straining with a large strain magnitude resulted in a negative effect on the mechanical properties of the tissue. In addition, dynamic straining induced a different alignment of cells and collagen in the superficial layers compared to the deeper layers of the construct. The presented model system can be used to systematically optimize culture protocols for engineered cardiovascular tissues

    Quantification of the Temporal Evolution of Collagen Orientation in Mechanically Conditioned Engineered Cardiovascular Tissues

    Get PDF
    Load-bearing soft tissues predominantly consist of collagen and exhibit anisotropic, non-linear visco-elastic behavior, coupled to the organization of the collagen fibers. Mimicking native mechanical behavior forms a major goal in cardiovascular tissue engineering. Engineered tissues often lack properly organized collagen and consequently do not meet in vivo mechanical demands. To improve collagen architecture and mechanical properties, mechanical stimulation of the tissue during in vitro tissue growth is crucial. This study describes the evolution of collagen fiber orientation with culture time in engineered tissue constructs in response to mechanical loading. To achieve this, a novel technique for the quantification of collagen fiber orientation is used, based on 3D vital imaging using multiphoton microscopy combined with image analysis. The engineered tissue constructs consisted of cell-seeded biodegradable rectangular scaffolds, which were either constrained or intermittently strained in longitudinal direction. Collagen fiber orientation analyses revealed that mechanical loading induced collagen alignment. The alignment shifted from oblique at the surface of the construct towards parallel to the straining direction in deeper tissue layers. Most importantly, intermittent straining improved and accelerated the alignment of the collagen fibers, as compared to constraining the constructs. Both the method and the results are relevant to create and monitor load-bearing tissues with an organized anisotropic collagen network

    The impact of deep versus standard neuromuscular block on intraoperative safety during laparoscopic surgery: an international multicenter randomized controlled double-blind strategy trial - EURO-RELAX TRIAL

    Get PDF
    Background: Muscle relaxants are routinely used during anesthesia to facilitate endotracheal intubation and to optimize surgical conditions. However, controversy remains about the required depth of neuromuscular block (NMB) needed for optimal surgical working conditions and how this relates to other outcomes. For instance, a deep neuromuscular block yields superior surgical working conditions compared to a standard NMB in laparoscopic surgery, however, a robust association to other (safety) outcomes has not yet been established.Methods: Trial design: an international multicenter randomized controlled double-blind strategy trial. Trial population: 922 patients planned for elective, laparoscopic or robotic, abdominal surgery. Intervention: Patients will be randomized to a deep NMB (post-tetanic count 1-2 twitches) or standard care (single-dose muscle relaxant administration at induction and repeated only if warranted by surgical team). Main trial endpoints: Primary endpoint is the difference in incidence of intraoperative adverse events during laparoscopic surgery graded according to ClassIntra (R) classification (i.e., ClassIntra (R) grade >= 2) between both groups. Secondary endpoints include the surgical working conditions, 30-day postoperative complications, and patients' quality of recovery.Discussion: This trial was designed to analyze the effect of deep neuromuscular block compared to standard neuromuscular block on intra- and postoperative adverse events in patients undergoing laparoscopic surgery.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

    Mammalian Target of Rapamycin Is a Therapeutic Target for Murine Ovarian Endometrioid Adenocarcinomas with Dysregulated Wnt/β-Catenin and PTEN

    Get PDF
    Despite the fact that epithelial ovarian cancers are the leading cause of death from gynecological cancer, very little is known about the pathophysiology of the disease. Mutations in the WNT and PI3K pathways are frequently observed in the human ovarian endometrioid adenocarcinomas (OEAs). However, the role of WNT/β-catenin and PTEN/AKT signaling in the etiology and/or progression of this disease is currently unclear. In this report we show that mice with a gain-of-function mutation in β-catenin that leads to dysregulated nuclear accumulation of β-catenin expression in the ovarian surface epithelium (OSE) cells develop indolent, undifferentiated tumors with both mesenchymal and epithelial characteristics. Combining dysregulated β-catenin with homozygous deletion of PTEN in the OSE resulted in development of significantly more aggressive tumors, which was correlated with inhibition of p53 expression and cellular senescence. Induced expression of both mTOR kinase, a master regulator of proliferation, and phosphorylation of its downstream target, S6Kinase was also observed in both the indolent and aggressive mouse tumors, as well as in human OEA with nuclear β-catenin accumulation. Ectopic allotransplants of the mouse ovarian tumor cells with a gain-of-function mutation in β-catenin and PTEN deletion developed into tumors with OEA histology, the growth of which were significantly inhibited by oral rapamycin treatment. These studies demonstrate that rapamycin might be an effective therapeutic for human ovarian endometrioid patients with dysregulated Wnt/β-catenin and Pten/PI3K signaling
    corecore