959 resultados para Acquired
Detecting the attributes of a wheat crop using digital imagery acquired from a low-altitude platform
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A low-altitude platform utilising a 1.8-m diameter tethered helium balloon was used to position a multispectral sensor, consisting of two digital cameras, above a fertiliser trial plot where wheat (Triticum spp.) was being grown. Located in Cecil Plains, Queensland, Australia, the plot was a long-term fertiliser trial being conducted by a fertiliser company to monitor the response of crops to various levels of nutrition. The different levels of nutrition were achieved by varying nitrogen application rates between 0 and 120 units of N at 40 unit increments. Each plot had received the same application rate for 10 years. Colour and near-infrared images were acquired that captured the whole 2 ha plot. These images were examined and relationships sought between the captured digital information and the crop parameters imaged at anthesis and the at-harvest quality and quantity parameters. The statistical analysis techniques used were correlation analysis, discriminant analysis and partial least squares regression. A high correlation was found between the image and yield (R2 = 0.91) and a moderate correlation between the image and grain protein content (R2 = 0.66). The utility of the system could be extended by choosing a more mobile platform. This would increase the potential for the system to be used to diagnose the causes of the variability and allow remediation, and/or to segregate the crop at harvest to meet certain quality parameters.
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Sepsis is associated with a systemic inflammatory response. It is characterised by an early proinflammatory response and followed by a state of immunosuppression. In order to improve the outcome of patients with infection and sepsis, novel therapies that influence the systemic inflammatory response are being developed and utilised. Thus, an accurate and early diagnosis of infection and evaluation of immune state are crucial. In this thesis, various markers of systemic inflammation were studied with respect to enhancing the diagnostics of infection and of predicting outcome in patients with suspected community-acquired infection. A total of 1092 acutely ill patients admitted to a university hospital medical emergency department were evaluated, and 531 patients with a suspicion of community-acquired infection were included for the analysis. Markers of systemic inflammation were determined from a blood sample obtained simultaneously with a blood culture sample on admission to hospital. Levels of phagocyte CD11b/CD18 and CD14 expression were measured by whole blood flow cytometry. Concentrations of soluble CD14, interleukin (IL)-8, and soluble IL-2 receptor α (sIL-2Rα) were determined by ELISA, those of sIL-2R, IL-6, and IL-8 by a chemiluminescent immunoassay, that of procalcitonin by immunoluminometric assay, and that of C-reactive protein by immunoturbidimetric assay. Clinical data were collected retrospectively from the medical records. No marker of systemic inflammation, neither CRP, PCT, IL-6, IL-8, nor sIL-2R predicted bacteraemia better than did the clinical signs of infection, i.e., the presence of infectious focus or fever or both. IL-6 and PCT had the highest positive likelihood ratios to identify patients with hidden community-acquired infection. However, the use of a single marker failed to detect all patients with infection. A combination of markers including a fast-responding reactant (CD11b expression), a later-peaking reactant (CRP), and a reactant originating from inflamed tissues (IL-8) detected all patients with infection. The majority of patients (86.5%) with possible but not verified infection showed levels exceeding at least one cut-off limit of combination, supporting the view that infection was the cause of their acute illness. The 28-day mortality of patients with community-acquired infection was low (3.4%). On admission to hospital, the low expression of cell-associated lipopolysaccharide receptor CD14 (mCD14) was predictive for 28-day mortality. In the patients with severe forms of community-acquired infection, namely pneumonia and sepsis, high levels of soluble CD14 alone did not predict mortality, but a high sCD14 level measured simultaneously with a low mCD14 raised the possibility of poor prognosis. In conclusion, to further enhance the diagnostics of hidden community-acquired infection, a combination of inflammatory markers is useful; 28-day mortality is associated with low levels of mCD14 expression at an early phase of the disease.
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Anti-factor VIII (FVIII) inhibitory IgG may arise as alloantibodies to therapeutic FVIII in patients with congenital hemophilia A, or as autoantibodies to endogenous FVIII in individuals with acquired hemophilia. We have described FVIII-hydrolyzing IgG both in hemophilia A patients with anti-FVIII IgG and in acquired hemophilia patients. Here, we compared the properties of proteolytic auto- and allo-antibodies. Rates of FVIII hydrolysis differed significantly between the two groups of antibodies. Proline-phenylalanine-arginine-methylcoumarinamide was a surrogate substrate for FVIII-hydrolyzing autoantibodies. Our data suggest that populations of proteolytic anti-FVIII IgG in acquired hemophilia patients are different from that of inhibitor-positive hemophilia A patients.
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The neurotransmitter serotonin (5-HT) modulates many functions important for life, e.g., appetite and body temperature, and controls development of the neural system. Disturbed 5-HT function has been implicated in mood, anxiety and eating disorders. The serotonin transporter (SERT) controls the amount of effective 5-HT by removing it from the extracellular space. Radionuclide imaging methods single photon emission tomography (SPET) and positron emission tomography (PET) enable studies on the brain SERTs. This thesis concentrated on both methodological and clinical aspects of the brain SERT imaging using SPET. The first study compared the repeatability of automated and manual methods for definition of volumes of interest (VOIs) in SERT images. The second study investigated within-subject seasonal variation of SERT binding in healthy young adults in two brain regions, the midbrain and thalamus. The third study investigated the association of the midbrain and thalamic SERT binding with Bulimia Nervosa (BN) in female twins. The fourth study investigated the association of the midbrain and hypothalamic/thalamic SERT binding and body mass index (BMI) in monozygotic (MZ) twin pairs. Two radioligands for SERT imaging were used: [123I]ADAM (studies I-III) and [123I]nor-beta-CIT (study IV). Study subjects included young adult MZ and dizygotic (DZ) twins screened from the FinnTwin16 twin cohort (studies I-IV) and healthy young adult men recruited for study II. The first study validated the use of an automated brain template in the analyses of [123I]ADAM images and proved automated VOI definition more reproducible than manual VOI definition. The second study found no systematic within-subject variation in SERT binding between scans done in summer and winter in either of the investigated brain regions. The third study found similar SERT binding between BN women (including purging and non-purging probands), their unaffected female co-twins and other healthy women in both brain regions; in post hoc analyses, a subgroup of purging BN women had significantly higher SERT binding in the midbrain as compared to all healthy women. In the fourth study, MZ twin pairs were divided into twins with higher BMI and co-twins with lower BMI; twins with higher BMI were found to have higher SERT binding in the hypothalamus/thalamus than their leaner co-twins. Our results allow the following conclusions: 1) No systematic seasonal variation exists in the midbrain and thalamus between SERT binding in summer and winter. 2) In a population-based sample, BN does not associate with altered SERT status, but alterations are possible in purging BN women. 3) The higher SERT binding in MZ twins with higher BMIs as compared to their leaner co-twins suggests non-genetic association between acquired obesity and the brain 5-HT system, which may have implications on feeding behavior and satiety.
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Symptomless nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) is very common in young children. Occasionally the carriage proceeds into mild mucosal diseases, such as sinusitis or acute otitis media, or into serious life-threatening diseases, such as pneumonia, sepsis or meningitis. Each year, up to one million children less than five years of age worldwide die of invasive pneumococcal diseases (IPD). Especially in the low-income countries IPD is a leading health problem in infants; 75% of all IPD cases occur before one year of age. This stresses the need of increased protection against pneumococcus in infancy. Anti-pneumococcal antibodies form an important component in the defence against pneumococcal infection. Maternal immunisation and early infant immunisation are two possible ways by which potentially protective antibody concentrations against pneumococci could be achieved in early infancy. The aim of this thesis is to increase the knowledge of antibody mediated protection against pneumococcal disease in infants and young children. We investigated the transfer of maternal anti-pneumococcal antibodies from Filipino mothers to their infants, the persistence of the transferred antibodies in the infants, the immunogenicity of the 23-valent pneumococcal polysaccharide vaccine (PPV) in infants and the response of the children to a second dose of PPV at three years of age. We also investigated the development of antibodies to pneumococcal protein antigens in relation to culture-confirmed pneumococcal carriage in infants. Serum samples were collected from the mothers, the umbilical cords and from the infants at young age as well as at three years of age. The samples were used to determine the antibody concentrations to pneumococcal serotypes 1, 5, 6B, 14, 18C and 19F, as well as to the pneumococcal proteins PspA, PsaA, Ply, PspC, PhtD, PhtDC and LytC by the enzyme immunoassay. The findings of the present study confirm previously obtained results and add to the global knowledge of responses to PPV in young children. Immunising pregnant women with PPV provides the infants with increased concentrations of pneumococcal polysaccharide antibodies. Of the six serotypes examined, serotypes 1 and 5 were immunogenic already in infants. At three years of age, the children responded well to the second dose of PPV suggesting that maternal and early infant immunisations might not induce hyporesponsiveness to polysaccharide antigens after subsequent immunisations. The anti-protein antibody findings provide useful information for the development of pneumococcal protein vaccines. All six proteins studied were immunogenic in infancy and the development of anti-protein antibodies started early in life in relation to pneumococcal carriage.
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INTRODUCTION: Recent studies in other European countries suggest that the prevalence of congenital cryptorchidism continues to increase. This study aimed to explore the prevalence and natural history of congenital cryptorchidism in a UK centre. METHODS: Between October 2001 and July 2008, 784 male infants were born in the prospective Cambridge Baby Growth Study. 742 infants were examined by trained research nurses at birth; testicular position was assessed using standard techniques. Follow-up assessments were completed at ages 3, 12, 18 and 24 months in 615, 462, 393 and 326 infants, respectively. RESULTS: The prevalence of cryptorchidism at birth was 5.9% (95% CI 4.4% to 7.9%). Congenital cryptorchidism was associated with earlier gestational age (p<0.001), lower birth weight (p<0.001), birth length (p<0.001) and shorter penile length at birth (p<0.0001) compared with other infants, but normal size after age 3 months. The prevalence of cryptorchidism declined to 2.4% at 3 months, but unexpectedly rose again to 6.7% at 12 months as a result of new cases. The cumulative incidence of "acquired cryptorchidism" by age 24 months was 7.0% and these cases had shorter penile length during infancy than other infants (p = 0.003). CONCLUSIONS: The prevalence of congenital cryptorchidism was higher than earlier estimates in UK populations. Furthermore, this study for the first time describes acquired cryptorchidism or "ascending testis" as a common entity in male infants, which is possibly associated with reduced early postnatal androgen activity.
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In April 2005, a SHOALS 1000T LIDAR system was used as an efficient alternative for safely acquiring data to describe the existing conditions of nearshore bathymetry and the intertidal zone over an approximately 40.7 km2 (11.8 nm2) portion of hazardous coastline within the Olympic Coast National Marine Sanctuary (OCNMS). Data were logged from 1,593 km (860 nm) of track lines in just over 21 hours of flight time. Several islands and offshore rocks were also surveyed, and over 24,000 geo-referenced digital still photos were captured to assist with data cleaning and QA/QC. The 1 kHz bathymetry laser obtained a maximum water depth of 22.2 meters. Floating kelp beds, breaking surf lines and turbid water were all challenges to the survey. Although sea state was favorable for this time of the year, recent heavy rainfall and a persistent low-lying layer of fog reduced acquisition productivity. The existence of a completed VDatum model covering this same geographic region permitted the LIDAR data to be vertically transformed and merged with existing shallow water multibeam data and referenced to the mean lower low water (MLLW) tidal datum. Analysis of a multibeam bathymetry-LIDAR difference surface containing over 44,000 samples indicated surface deviations from –24.3 to 8.48 meters, with a mean difference of –0.967 meters, and standard deviation of 1.762 meters. Errors in data cleaning and false detections due to interference from surf, kelp, and turbidity likely account for the larger surface separations, while the remaining general surface difference trend could partially be attributed to a more dense data set, and shoal-biased cleaning, binning and gridding associated with the multibeam data for maintaining conservative least depths important for charting dangers to navigation. (PDF contains 27 pages.)
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Unlike Escherichia coli, the cyanobacterium Synechocystis sp. strain PCC 6803 is insensitive to chill (5 degrees C) in the dark but rapidly losses viability when exposed to chill in the light (100 mu mol photons m(-2) s(-1)). Preconditioning at a low temperature (15 degrees C) greatly enhances the chill-light tolerance of Synechocystis sp. strain PCC 6803. This phenomenon is called acquired chill-light tolerance (ACLT). Preconditioned wild-type cells maintained a substantially higher level of alpha-tocopherol after exposure to chill-light stress. Mutants unable to synthesize alpha-tocopherol, such as slr1736, slr1737, slr0089, and slr0090 mutants, almost completely lost ACLT. When exposed to chill without light, these mutants showed no or a slight difference from the wild type. When complemented, the slr0089 mutant regained its ACLT. Copper-regulated expression of slr0090 from P-petE controlled the level of et-tocopherol and ACLT. We conclude that alpha-tocopherol is essential for ACLT of Synechocystis sp. strain PCC 6803. The role of a-tocopherol in ACLT may be based largely on a nonantioxidant activity that is not possessed by other tocopherols or pathway intermediates.
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Imaging mechanism of underwater topography by SAR and a underwater topography SAR detection model built on the theory of underwater topography detection with SAR image presented by Yuan Yeli are used to detect the underwater topography of Shuangzi Reefs in the Nansha Islands with three scenes of SAR images acquired in different time. Detection results of three SAR images are compared with the chart topography and the detection errors are analyzed. Underwater topography detection experiments of Shuangzi Reefs show that the detection model is practicable. The detection results indicate that SAR images acquired in different time also can be used to detect the underwater topography, and the detection results are affected by the ocean conditions in the SAR acquiring time.
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Draper, J., Darby, R.M., Beckmann, M., Maddison, A.L., Mondhe, M., Sheldrick, C., Taylor, J., Goodacre, R., and Kell, D.B. (2002) Metabolic Engineering, metabolite profiling and machine learning to investigate the phloem-mobile signal in systemic acquired resistance in tobacco. First International Congress on Plant Metabolomics, Wageningen, The Netherlands
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Clarke, S. M., Mur, L. A. J., Wood, J. E., & Scott, I. M. (2004). Salicylic acid dependent signaling promotes basal thermotolerance but is not essential for acquired thermotolerance in Arabidopsis thaliana. The Plant Journal, 38(3), 432-447. Sponsorship: BBSRC RAE2008
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Irish literature on Acquired Brain Injury (ABI) is very scant and is mainly deficits and/or needs based. The focus is generally on how to manage the short term needs of the younger population with ABI. The starting position of my thesis is that people living long-term with ABI are important participants in developing knowledge about this social phenomenon, living with ABI while accepting that their brain injury does not determine them. Six mature adults with ABI and their six significant others participated in this longitudinal study. Using a narrative approach in interviews, over twenty months, five repeat individual interviews with each of the twelve participants was held. From this I gained an understanding of their lived experiences, their life-world and their experiences of our local public ABI/disability services, systems and discourse. Along with this new empirical data, theoretical developments from occupational therapy, occupational science, sociology, and disability studies were also used within a meta-narrative informed by critical theory and critical realism to develop a synthesis of this study. Social analysis of their narratives co-constructed with me, allowed me generate nuanced insights into tendencies and social processes that impacted and continues to impact on their everyday-everynight living. I discuss in some depth here, the relational attitudinal, structural, occupational and environmental supports, barriers or discrimination that they face(d) in their search for social participation and community inclusion. Personal recognition of the disabled participants by their family, friends and/or local community, was generally enhanced after much suffering, social supports, slow recovery, and with some form of meaningful occupational engagement. This engagement was generally linked with pre-injury interests or habits, while Time itself became both a major aid and a need. The present local ABI discourse seldom includes advocacy and inclusion in everyday/every night local events, yet most participants sought both peer-support or collective recognition, and social/community inclusion to help develop their own counter-discourse to the dominant ABI discourse. This thesis aims to give a broad social explanation on aspects of their social becoming, 'self-sameness' and social participation, and the status of the disabled participants wanting to live 'the slow life'. Tensions and dialectical issues involved in moving from the category of a person in coma, to person with a disability, to being a citizen should not demote the need for special services. While individualized short-term neuro-rehabilitation is necessary, it is not sufficient. Along with the participants, this researcher asks that community health and/or social care planners and service-providers rethink how ABI is understood and represented, and how people with ABI are included in their local communities