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Subtle Changes (subtle + change)
Selected AbstractsZinc Hydrazide and Zinc Alkoxide Hydrazide Cages with Zn4N8 and Zn4N6O Cores , Cluster Isomerism as a Result of Subtle Changes in Ligand SizeEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2006Surajit Jana Abstract The hydrazide cluster [(iPrZn)4(NHNMe2)4] (1) was synthesised by the reaction of diisopropylzinc with N,N -dimethylhydrazine and was characterised by 1H- and 13C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X-ray crystallography. This compound forms asymmetric aggregates containing Zn4N8 cores. The Zn atoms in these aggregates are arranged in topological tetrahedra in which the triangular faces are bridged by NHNMe2 substituents. Each NH group is connected to two Zn atoms and each NMe2 group to one Zn atom. Alkoxide clusters were prepared in one-pot syntheses by treating diisopropylzinc solutions with mixtures of N,N -dimethylhydrazine and ROH (R = Et, iPr). The resulting compounds have the formula [(iPrZn)4(NHNMe2)3(OR)] [R = Et (3), iPr(4)] and contain Zn4N6O cages, such that one NHNMe2 in 1 is replaced by one alkoxide group. Two different aggregation modes were found for these Zn4N6O cages. In compound 3, one Zn atom is bound to two NMe2 groups and one NH group. The other three Zn atoms each have three bonds to NH groups and one dative bond to an NMe2 group. The cage consists of one four-membered and one six-membered ring as well as four five-membered rings. In compound 4, the fourth zinc atom is exclusively bonded to three anionic NH functions in such a way that the rings in the cage are all five-membered. Compounds 3 and 4 were characterised by NMR spectroscopy and single-crystal X-ray diffraction. Hydrazide hydroxide clusters were also obtained through the reaction of a diisopropylzinc solution with N,N -dimethylhydrazine and a small amount of water. The structure of the resulting cocrystalline material, [(iPrZn)4(NHNMe2)4]·[(iPrZn)4(NHNMe2)3(OH)] (2), was also confirmed by X-ray diffraction. The hydroxide cluster in 2 contains a Zn4N6O cage, with a similar aggregation mode to that of 4. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Heterobimetallic Systems Containing Organometallic and Classical Coordination Sites: Effects of Subtle Changes in the Werner-Type SiteEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2005Tianlu Sheng Abstract Several highly unsymmetrical heterodinuclear Mn/Zn complexes are reported, in which an organometallic CpMn-(CO)2 fragment and a classical Werner-type zinc coordination unit are arranged in close proximity by means of a bridging pyrazolate. Ligand scaffolds differing in the chelate size of the tripodal tetradentate {N4} binding site, and different coligands for zinc are employed. Both the zinc-devoid precursor compounds and the bimetallic complexes with zinc(II) nested in the tris(pyridylalkyl)amine type {N4} compartment have been characterized by X-ray crystallography. Structural and spectroscopic features as well as the redox potentials of the MnI/MnII couple indicate slight effects of the redox-inactive Werner-type subunit on the properties of the organometallic site. Oxidation is highly localized at the organometallic manganese site, as is evidenced by IR and EPR spectroscopy and supported by DFT calculations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Released nucleotides amplify the cilium-dependent, flow-induced [Ca2+]i response in MDCK cellsACTA PHYSIOLOGICA, Issue 3 2009H. A. Praetorius Abstract Aim:, Changes in perfusate flow produce increases in [Ca2+]i in renal epithelial cells. Cultured renal epithelia require primary cilia to sense subtle changes in flow. In perfused kidney tubules this flow response is caused by nucleotide signalling via P2Y2 receptors. It is, however, not known whether nucleotides are released by mechanical stress applied to renal primary cilia. Here we investigate whether nucleotides are released during the cilium-dependent flow response and contribute to the flow-induced, cilium-dependent [Ca2+]i signal. Methods:, MDCK cells loaded with Fluo-4-AM were observed at 37 °C in semi-open single or closed-double perfusion chambers. Results:, Our data suggest a purinergic component of the cilium-dependent flow-response: (1) ATP scavengers and P2 receptor antagonists reduced (55%) the cilium-dependent flow-response; (2) ATP added at subthreshold concentration sensitized the renal epithelia to flow changes; (3) increases in fluid flow transiently enhanced the ATP concentration in the superfusate (measured by biosensor-cells). To test if nucleotides were released in sufficient quantities to stimulate renal epithelia we used non-confluent MDCK cells without cilia as reporter cells. We confirmed that non-confluent cells do not respond to changes in fluid flow. Placing confluent, ciliated cells upstream in the in-flow path of the non-confluent cells made them responsive to fluid flow changes. This phenomenon was not observed if either non-confluent or de-ciliated confluent cells were placed upstream. The [Ca2+]i -response in the non-confluent cells with ciliated cells upstream was abolished by apyrase and suramin. Conclusion:, This suggests that subtle flow changes sensed by the primary cilium induces nucleotide release, which amplifies the epithelial [Ca2+]i -response. [source] 3D In-Vivo Optical Skin Imaging for Topographical Quantitative Assessment of Non-Ablative Laser TechnologyDERMATOLOGIC SURGERY, Issue 3 2002Paul M. Friedman MD background. A new method for treating facial rhytides and acne scars with nonablative laser and light source techniques has recently been introduced. Given the inherent limitations of photographic and clinical evaluation to assess subtle changes in rhytides and surface topography, a new noninvasive objective assessment is required to accurately assess the outcomes of these procedures. objective. The purpose of this study was to measure and objectively quantify facial skin using a novel, noninvasive, In-vivo method for assessing three-dimensional topography. This device was used to quantify the efficacy of five treatment sessions with the 1064 nm QS Nd:YAG laser for rhytides and acne scarring, for up to six months following laser treatment. methods. Two subjects undergoing facial rejuvenation procedures were analyzed before and after therapy using a 30-mm, three-dimensional microtopography imaging system (PRIMOS, GFM, Teltow, Germany). The imaging system projects light on to a specific surface of the skin using a Digital Micromirror Device (DMDÔ Texas Instruments, Irving, TX) and records the image with a CCD camera. Skin Surface microtopography is reconstructed using temporal phase shift algorithms to generate three-dimensional images. Measurements were taken at baseline, at various times during the treatment protocol, and then at three and six-month follow-up visits. Silicone skin replicas (FLEXICO, Herts, England) were also made before and after the laser treatment protocol for comparison to In-vivo acquisition. results. Skin roughness decreased by 11% from baseline after three treatment sessions in the wrinkles subject, while a 26% improvement of skin roughness was recorded by 3D In-vivo assessment six months following the fifth treatment session. The subject with acne scarring demonstrated a 33% decrease in roughness analysis after three treatment sessions by 3D In-vivo assessment. A 61% improvement in surface topography was recorded 3-months following the fifth treatment session, which was maintained at the 6-month follow-up. conclusion. Three-dimensional In-vivo optical skin imaging provided a rapid and quantitative assessment of surface topography and facial fine lines following multiple treatment sessions with a 1064-nm QS Nd:YAG laser, correlating with clinical and subjective responses. This imaging technique provided objective verification and technical understanding of nonablative laser technology. Wrinkle depth and skin roughness decreased at the three and six-month follow-up evaluations by 3D In-vivo assessment, indicating ongoing dermal collagen remodeling after the laser treatment protocol. Future applications may include comparison of nonablative laser technology, optimization of treatment regimens, and objective evaluation of other aesthetic procedures performed by dermatologists. [source] Rhinophyma and Coexisting Occult Skin CancersDERMATOLOGIC SURGERY, Issue 2 2001Michael E. Lutz MD Background. Although coexistent tumors have been reported in patients with rhinophyma, few reports have described the coexistence of rhinophyma and an occult infiltrating squamous cell carcinoma (SCC). Objective. Preoperatively and during rhinophymaplasty, recognition of subtle changes can suggest an underlying malignancy. Methods. A large infiltrating SCC was noted during electrosurgical rhinophymaplasty. Mohs micrographic surgery was performed to clear the tumor. Results. The patient was tumor-free with no evidence of recurrence at 1-year follow-up. Conclusion. In the evaluation of changing rhinophyma or subtle changes in tissue noted during rhinophymaplasty, physicians must consider the possibility of an underlying malignancy. [source] Neuropsychological and neurophysiological findings in individuals suspected to be at risk for schizophrenia: preliminary results from the Basel early detection of psychosis study , Früherkennung von Psychosen (FEPSY)ACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2003U. Gschwandtner Objective: Our study aims to establish a scientific basis for the very early detection of patients at risk for schizophrenia during the nonspecific prodromal phase of the disorder and to predict its outbreak. Method: A multidomain approach is used. After screening, approved psychopathological, neurophysiological, neuropsychological and neuroradiological investigations are used to assess a sample of individuals suspected to be at risk for schizophrenia. Results: Neuropsychological and fine motor functioning tests as well as eye movement measurements showed statistically significant differences (P<0.01) between individuals suspected to be at risk for schizophrenia and healthy controls. Conclusion: Individuals suspected to be at risk for schizophrenia show specific impairments in various investigations including neuropsychological and fine motor functioning tests as well as eye movement measurements. A set of methods sensitive to even subtle changes in normal functioning may prove useful in predicting the subsequent outbreak of schizophrenia. [source] The transformation of kinship and the family in late Anglo-Saxon EnglandEARLY MEDIEVAL EUROPE, Issue 3 2001Andrew Wareham The development of the family into a small unit in which descent was traced almost exclusively through the male line is regarded as a major turning point in medieval European history. The early stages of the formation of agnatic kinship have usually been connected to strategies designed to preserve and retain control of patrimonies and castles, arising from the breakdown of public order. In this article it is suggested that the emergence of new kinship values was connected to the investment of aristocratic energy and resources in monastic programmes, and to subtle changes in lay involvement with the rituals associated with death and the salvation of souls. [source] The implications of different species concepts for describing biodiversity patterns and assessing conservation needs for African birdsECOGRAPHY, Issue 5 2005Shaun Dillon It has been suggested that switching from the widely used Biological Species Concept to a Phylogenetic Species Concept, would result in the appearance of hitherto neglected patterns of endemism. The problem has mainly been analyzed with respect to endemic taxa and for rather limited geographical regions, but will here be analysed for the entire resident avifauna of sub-Saharan Africa. A database of African bird distributions was re-edited to create two new datasets representing 1572 biological species and 2098 phylogenetic species. Species richness patterns were virtually identical with the two taxonomies, and only subtle changes were found in the geographical variation in range-size rarity sum. However, there were some differences in the most range-restricted species, with increased complexity of long-recognized centres of endemism. Overall, then, the large-scale biogeographic patterns are robust to changes in species concepts. This reflects the aggregated nature of endemism, with certain areas acting as "species pumps" and large intervening areas being characterised by a predominance of widespread species which distribute themselves in accordance with contemporary environmental conditions. The percentages of phylogenetic and threatened species captured in a BSC near-minimum set of 64 grid-cells and a PSC near-maximum set, with the same number of grid-cells, are very similar. [source] Do horses suffer from irritable bowel syndrome?EQUINE VETERINARY JOURNAL, Issue 9 2009J. O. HUNTER Summary Irritable bowel syndrome (IBS) in man is not a single entity but has several causes. One of the most common forms has similarities with colic and laminitis in horses. Undigested food residues may pass from the small intestine into the colon where bacterial fermentation produces chemicals that lead to disease. In horses the consequences may be disastrous, but in healthy humans such malabsorption may not be harmful. After events such as bacterial gastroenteritis or antibiotic treatment, an imbalance of the colonic microflora with overgrowth of facultative anaerobes may arise, leading to malfermentation and IBS. It is not known whether such subtle changes may likewise be present in the microflora of horses who are susceptible to colic and laminitis. Metabolomic studies of urine and faeces may provide a suitable way forward to identify such changes in the horse's gut and thus help to identify more accurately those at risk and to provide opportunities for the development of improved treatment. [source] Photochromic Properties of Perhydro- and Perfluorodithienylcyclopentene Molecular SwitchesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 10 2003Jaap J. D. de Jong Abstract Various substituted phenylthienyl perhydro- and perfluorocyclopentenes have been synthesized in order to compare their spectroscopic and photochromic properties. The difference in the electron densities of the central cyclopentene moieties in the perhydrocyclopentene and perfluorocyclopentene molecular switches has only a small effect on the absorption maxima of the electronic spectra, but causes some subtle changes in substituent and solvatochromic effects. The photochromic behaviour is remarkably similar, and both type of switches combine excellent quantum yields (0.6) with high degrees of photoconversion (> 0.85). The main difference is the lower photochemical and thermal stability of the perhydrocyclopentene molecular switches. It is concluded that in most studies the perhydrocyclopentenes are an excellent alternative for the perfluorocyclopentenes, while the perfluorocyclopentenes might be better suited for applications such as data storage, which depend critically on fatigue resistance and thermal stability. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Lessons from the past: the collapse of Jamaican coral reefsFISH AND FISHERIES, Issue 2 2009Marah J. Hardt Abstract Since Pre-Columbian times, humans have exploited Jamaican marine ecosystems with significant consequences for flora and fauna. This study focuses on the history of reef fish exploitation in Jamaica, from first human occupation to the present day, to determine how past fishing activities contributed to subsequent declines in the coral reef ecosystem. The pattern of declining reef fish populations was nonlinear. Reef fish first declined in prehistoric times but then potentially recovered, following genocide of the native human population. Reduced fishing pressure lasted until the mid-19th century. At that time, depletion of reef fish populations again occurred with a precipitous decline from the 1850s to the 1940s. The final shift from relatively abundant to overfished marine fauna corresponded to subtle changes in fish trap design as well as development of recreational fishing. Government subsidies throughout the second half of the 20th century exacerbated the declines. This analysis shows that local artisanal fisheries with relatively low levels of effort and seemingly subtle shifts in technology can significantly impact the coral reef ecosystem and that declines occurred decades to centuries before modern ecological studies began. This research shows how historical analysis can be a powerful tool to minimize shifted baselines and establish realistic targets for recovery and sustainable management of marine ecosystems. [source] Subtle top-down control of a freshwater meiofaunal assemblage by juvenile fishFRESHWATER BIOLOGY, Issue 9 2010GERARD DINEEN Summary 1. Top-down control of prey assemblages by fish predators has been clearly demonstrated in lakes (for zooplankton prey) and rivers (for macroinvertebrate prey). Fish predation can have a significant impact on the body size of prey assemblages; often large-bodied prey are reduced in abundance, and indirect facilitation of small-bodied prey occurs potentially initiating a trophic cascade. 2. Benthic communities in aquatic ecosystems also include a numerous and functionally important meiofaunal-sized component, but in freshwaters the impact of fish predation on meiofaunal assemblages is unknown. We used a laboratory microcosm study to explore the impact of juvenile fish predation on the abundance and size structure of a riverine meiofaunal assemblage. 3. The presence of fish in our microcosms had no significant effect on overall meiofaunal (temporary and permanent) abundance. However, for the Copepoda, we found the first evidence of top-down control of freshwater meiofaunal assemblages; in microcosms with juvenile fish, the abundance of large-bodied Copepoda was significantly reduced, whereas small-bodied Copepoda were significantly more abundant suggesting indirect facilitation. 4. We conclude that predation by juvenile fish can alter the structure of freshwater meiofaunal assemblages, although we do not yet know whether these relatively subtle changes are overwhelmed by large-scale events such as flow disturbances. [source] Combined therapy of silymarin and desferrioxamine in patients with ,-thalassemia major: a randomized double-blind clinical trialFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2009Marjan Gharagozloo Abstract Silymarin, a flavonolignan complex isolated from Silybum marianum, has a strong antioxidant, hepatoprotective, and iron chelating activities. The present study was designed to investigate the therapeutic activity of orally administered silymarin in patients with thalassemia major under conventional iron chelation therapy. A 3-month randomized, double-blind, clinical trial was conducted in 59 ,-thalassemia major patients in two well-matched groups. Patients were randomized to receive a silymarin tablet (140 mg) three times a day plus conventional desferrioxamine therapy. The second group received the same therapy but a placebo tablet instead of silymarin. Clinical laboratory tests were assessed at the beginning and the end of the trial, except for serum ferritin level that was assessed at the middle of the trial as well. Results of this study revealed that the combined therapy was well tolerated and more effective than desferrioxamine in reducing serum ferritin level. Significant improvement in liver alkaline phosphatase and glutathione levels of red blood cells was also observed in silymarin-treated ,-thalassemia patients. However, no significant difference in serum ferritin levels was detected between silymarin and placebo groups after 1.5 and 3 months treatment, probably because of insufficient sample size to detect subtle changes in ferritin levels between groups. This is the first report showing the beneficial effects of silymarin in thalassemia patients and suggests that silymarin in combination with desferrioxamine can be safely and effectively used in the treatment of iron-loaded patients. [source] The benefits of rapid 3D fMRIINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2010Martin A. Lindquist Abstract Functional magnetic resonance imaging (fMRI) provides the ability to image blood dynamics through the entire brain with a high spatial resolution. However, the temporal resolution is much slower than the underlying neuronal activity one seeks to infer. Recent developments in rapid imaging allow 3D fMRI studies to be performed at a temporal resolution of 100 ms; a 10-fold increase compared to standard approaches. This increase in temporal resolution offers a number of potential benefits. First, it allows the focus of analysis to be shifted from changes in blood flow taking place 5,8 s after neuronal activity to more transient changes taking place immediately following activation. We argue that studying these changes provides valuable information about the relative timing of activation across different regions of the brain, which is crucial for inferring brain pathways. Second, rapid imaging allows for the efficient modeling of physiological artifacts without problems with aliasing; something that is difficult at standard resolutions. We illustrate how removal of these artifacts provides the increase in signal-to-noise ratio required for studying the subtle changes in oxygenation we are interested in. Finally, we show how high temporal resolution data provides the opportunity to focus the analysis on the rate of change in oxygenation rather than the level of oxygenation as is the current practice. The price of performing rapid imaging studies is a decrease in spatial resolution. However, we argue that the resolution is still comparable to the effective resolution used in most fMRI studies. We illustrate our approach using two fMRI data sets. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 14,22, 2010 [source] Iron K -edge anomalous small-angle X-ray scattering at 15-ID-D at the Advanced Photon SourceJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2007Nigel Kirby Small-angle X-ray scattering (SAXS) is an ideal technique for characterizing inorganic nanoparticles in biological specimens large enough to be representative of tissues. As tissues consist of complex mixtures of structures, identifying particular structural features from single-wavelength scattering data can be problematic. Synchrotron SAXS can supply element-specific structural information in complex samples, using anomalous scattering close to absorption edges. Anomalous dispersion is a secondary effect that produces relatively subtle changes in scattering patterns. In order to utilize this effect for anomalous SAXS analysis, stringent control of instrument performance is required. This work outlines the development of high-quality data collection and processing strategies for Fe K -edge anomalous SAXS on the ChemMatCARS beamline at the Advanced Photon Source (APS), Chicago, with an emphasis on intensity normalization. The methods reported here were developed during a study of iron-loaded mammal tissues, but could equally well be applied to other complex specimens. [source] Earliest Mineral and Matrix Changes in Force-Induced Musculoskeletal Disease as Revealed by Raman Microspectroscopic Imaging,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2004Catherine P Tarnowski Abstract Craniosynostosis, premature fusion of the skull bones at the sutures, is the second most common human birth defect in the skull. Raman microspectroscopy was used to examine the composition, relative amounts, and locations of the mineral and matrix produced in mouse skulls undergoing force-induced craniosynostosis. Raman imaging revealed decreased relative mineral content in skulls undergoing craniosynostosis compared with unloaded specimens. Introduction: Raman microspectroscopy, a nondestructive vibrational spectroscopic technique, was used to examine the composition, relative amounts, and locations of the mineral and matrix produced in mouse skulls undergoing force-induced craniosynostosis. Craniosynostosis, premature fusion of the skull bones at the sutures, is the second most common birth defect in the face and skull. The calvaria, or flat bones that comprise the top of the skull, are most often affected, and craniosynostosis is a feature of over 100 human syndromes and conditions. Materials and Methods: Raman images of the suture, the tips immediately adjacent to the suture (osteogenic fronts), and mature parietal bones of loaded and unloaded calvaria were acquired. Images were acquired at 2.6 × 2.6 ,m spatial resolution and ranged in a field of view from 180 × 210 ,m to 180 × 325 ,m. Results and Conclusions: This study found that osteogenic fronts subjected to uniaxial compression had decreased relative mineral content compared with unloaded osteogenic fronts, presumably because of new and incomplete mineral deposition. Increased matrix production in osteogenic fronts undergoing craniosynostosis was observed. Understanding how force affects the composition, relative amounts, and location of the mineral and matrix provides insight into musculoskeletal disease in general and craniosynostosis in particular. This is the first report in which Raman microspectroscopy was used to study musculoskeletal disease. These data show how Raman microspectroscopy can be used to study subtle changes that occur in disease. [source] Stress and GABAA receptorsJOURNAL OF NEUROCHEMISTRY, Issue 5 2010Kelly J. Skilbeck J. Neurochem. (2010) 112, 1115,1130. Abstract GABAA receptors are sensitive to subtle changes in the environment in both early-life and adulthood. These neurochemical responses to stress in adulthood are sex-dependent. Acute stress induces rapid changes in GABAA receptors in experimental animals, with the direction of the changes varying according to the sex of the animals and the stress-paradigm studied. These rapid alterations are of particular interest as they provide an example of fast neurotransmitter system plasticity that may be mediated by stress-induced increases in neurosteroids, perhaps via effects on phosphorylation and/or receptor trafficking. Interestingly, some studies have also provided evidence for long-lasting changes in GABAA receptors as a result of exposure to stressors in early-life. The short- and long-term stress sensitivity of the GABAergic system implicates GABAA receptors in the non-genetic etiology of psychiatric illnesses such as depression and schizophrenia in which stress may be an important factor. [source] Measurement of Whole-Brain Atrophy in Multiple SclerosisJOURNAL OF NEUROIMAGING, Issue 2004Daniel Pelletier MD ABSTRACT Brain atrophy reflects the net result of irreversible and destructive pathological processes in multiple sclerosis (MS). The gross morphological changes can be accurately quantified using standard magnetic resonance imaging (MRI) acquisitions and various image analysis tools. The current methods used to assess whole-brain atrophy in patients with MS can be classified into 2 groups based on their reliance on segmentation and registration. Segmentation-based methods employed to measure whole-brain atrophy in MS include the brain parenchymal fraction, the index of brain atrophy, the whole-brain ratio, the brain to intracranial capacity ratio, fuzzy connectedness/Udupa's method, 3DVIEWNIX, the Alfano method, and SIENAX. Current registration-based methods used to measure whole-brain atrophy in MS include the brain boundary shift integral, SIENA, statistical parametric mapping, template-driven seg mentation, and voxel-based morphometry. Most of the methods presented here are sensitive to subtle changes in brain structures and have been successfully applied to MS as measures of whole-brain atrophy. Yet comparative studies of these methods are limited and are complicated by the lack of a gold standard for image acquisition, a segmentation algorithm, an image analysis method, or a reproducibility measure. Overall, the measure of whole-brain atrophy from MRI contributes to an appreciation of the dynamics of MS pathology and its relationship to the clinical course of MS. Determination of the relative reproducibility, precision, sensitivity, and validity of these methods will promote the use of whole-brain atrophy measures as components of comprehensive MRI-based outcome assessment in MS clinical trials. [source] Monitoring of batch processes through state-space modelsAICHE JOURNAL, Issue 6 2004Jay H. Lee Abstract The development of a state-space framework for monitoring batch processes that can complement the existing multivariate monitoring methods is presented. A subspace identification method will be used to extract the dynamic and batch-to-batch trends of the process and quality variables from historical operation data in the form of a "lifted" state-space stochastic model. A simple monitoring procedure can be formed around the state and residuals of the model using appropriate scalar statistical metrics. The proposed state-space monitoring framework complements the existing multivariate methods like the multi-way PCA method, in that it allows us to build a more complete statistical representation of batch operations and use it with incoming measurements for early detection of not only large, abrupt changes but also subtle changes. In particular, it is shown to be effective for detecting changes in the batch-to-batch correlation structure, slow drifts, and mean shifts. Such information can be useful in adapting the prediction model for batch-to-batch control. The framework allows for the use of on-line process measurements and/or off-line quality measurements. When both types of measurements are used in model building, one can also use the model to predict the quality variables based on incoming on-line measurements and quality measurements of previous batches. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1198,1210, 2004 [source] Can the introduction of a quality of life tool affect individual professional practice and the quality of care planning in a community mental health team?JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 10 2009N. MURPHY rmn dip he bsc (hons) msc pgchepr Accessible summary ,,Audit should not be restricted to one form of methodology and should embrace mixing methods of data collection. ,,Use of a quality of life tool allows users more of a voice, enhancing the partnership with service providers and presenting an alternate view of risk. ,,Implementation of any change to practice needs to address local level barriers and engage the service providers in the process, therefore, avoiding the common perception of being given more work without negotiation and feelings of alienation. Abstract This practice development paper demonstrates the scope for creativity in mixing audit and methods of investigation. It details the evolution of Quality of Life (QOL) perspectives and relates them to the practice of care planning. The process proved enlightening and affirming to practitioners and engaged them in considering value-based practice (recovery-orientated) from the perspective of the client. It was clear that subtle changes to care planning emerged, and the goal of giving responsibility for self determining issues was addressed. [source] Differential Increase in Taurine Levels by Low-Dose Ethanol in the Dorsal and Ventral Striatum Revealed by Microdialysis With On-Line Capillary ElectrophoresisALCOHOLISM, Issue 7 2004A Smith Ethanol increases taurine efflux in the nucleus accumbens or ventral striatum (VS), a dopaminergic terminal region involved in positive reinforcement. However, this has been found only at ethanol doses above 1 g/kg intraperitoneally, which is higher than what most rats will self-administer. We used a sensitive on-line assay of microdialysate content to test whether lower doses of ethanol selectively increase taurine efflux in VS as opposed to other dopaminergic regions not involved in reinforcement (e.g., dorsal striatum; DS). Adult male rats with microdialysis probes in VS or DS were injected with ethanol (0, 0.5, 1, and 2 g/kg intraperitoneally), and the amino acid content of the dialysate was measured every 11 sec using capillary electrophoresis and laser-induced fluorescence detection. In VS, 0.5 g/kg ethanol significantly increased taurine levels by 20% for 10 min. A similar increase was seen after 1 g/kg ethanol, which lasted for about 20 min after injection. A two-phased taurine efflux was observed with the 2.0 g/kg dose, where taurine was increased by 2-fold after 5 min but it remained elevated by 30% for at least 60 min. In contrast, DS exhibited much smaller dose-related increases in taurine. Glycine, glutamate, serine, and ,-aminobutyric acid were not systematically affected by lower doses of ethanol; however, 2 g/kg slowly decreased these amino acids in both brain regions during the hour after injection. These data implicate a possible role of taurine in the mechanism of action of ethanol in the VS. The high sensitivity and time resolution afforded by capillary electrophoresis and laser-induced fluorescence detection will be useful for detecting subtle changes of neuronally active amino acids levels due to low doses of ethanol. [source] Redesigning alkylated diphenylamine antioxidants for modern lubricantsLUBRICATION SCIENCE, Issue 1 2007Vincent J. Gatto This paper describes a new alkylation technology that is very effective at synthesizing structurally different alkylated diphenylamine chemistries relative to those currently available to lubricant formulators. Examples are provided showing how this technology can be used in a practical way to produce a variety of chemically modified nonylated diphenylamine types. One example is also provided illustrating the preparation of a higher molecular weight dodecylated diphenylamine. Engine oil performance data utilizing pressurized differential scanning calorimetry (PDSC), the thermo-oxidation engine oil simulation test, and a bulk oil oxidation test demonstrate that subtle changes in alkylated diphenylamine chemical composition can result in significant oxidation and deposit control performance enhancements or losses. Examples of similar performance responses in industrial oils are demonstrated utilizing PDSC and the rotating pressure vessel oxidation test. These performance changes are directly related to specific structural changes in the modified products. Copyright © 2006 John Wiley & Sons, Ltd. [source] Toward direct mapping of neuronal activity: MRI detection of ultraweak, transient magnetic field changes,MAGNETIC RESONANCE IN MEDICINE, Issue 6 2002Jerzy Bodurka Abstract A novel method based on selective detection of rapidly changing ,B0 magnetic fields and suppression of slowly changing ,B0 fields is presented. The ultimate goal of this work is to present a method that may allow detection of transient and subtle changes in B0 in cortical tissue associated with electrical currents produced by neuronal activity. The method involves the detection of NMR phase changes that occur during a single-shot spin-echo (SE) echo-planar sequence (EPI) echo time. SE EPI effectively rephases all changes in B0 that occur on a time scale longer than the echo time (TE) and amplifies all ,B0 changes that occur during TE/2. The method was tested on a phantom that contains wires in which current can be modulated. The sensitivity and flexibility of the technique was demonstrated by modulation of the temporal position and duration of the stimuli-evoked transient magnetic field relative to the 180 RF pulse in the imaging sequence,requiring precise stimulus timing. Currently, with this method magnetic field changes as small as 2 × 10,10 T (200 pT) and lasting for 40 msec can be detected. Implications for direct mapping of brain neuronal activity with MRI are discussed. Magn Reson Med 47:1052,1058, 2002. Published 2002 Wiley-Liss, Inc. [source] Limb-girdle muscular dystrophies , from genetics to molecular pathologyNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2004S. H. Laval The limb-girdle muscular dystrophies are a diverse group of muscle-wasting disorders characteristically affecting the large muscles of the pelvic and shoulder girdles. Molecular genetic analyses have demonstrated causative mutations in the genes encoding a disparate collection of proteins involved in all aspects of muscle cell biology. Muscular dystrophy includes a spectrum of disorders caused by loss of the linkage between the extracellular matrix and the actin cytoskeleton. Within this are the forms of limb-girdle muscular dystrophy caused by deficiencies of the sarcoglycan complex and by aberrant glycosylation of ,-dystroglycan caused by mutations in the fukutin-related protein gene. However, other forms of this disease have distinct pathophysiological mechanisms. For example, deficiency of dysferlin disrupts sarcolemmal membrane repair, whilst loss of calpain-3 may exert its pathological influence either by perturbation of the I,B,/NF-,B pathway, or through calpain-dependent cytoskeletal remodelling. Caveolin-3 is implicated in numerous cell-signalling pathways and involved in the biogenesis of the T-tubule system. Alterations in the nuclear lamina caused by mutations in laminA/C, sarcomeric changes in titin, telethonin or myotilin at the Z-disc, and subtle changes in the extracellular matrix proteins laminin-,2 or collagen VI can all lead to a limb-girdle muscular dystrophy phenotype, although the specific pathological mechanisms remain obscure. Differential diagnosis of these disorders requires the careful application of a broad range of disciplines: clinical assessment, immunohistochemistry and immunoblotting using a panel of antibodies and extensive molecular genetic analyses. [source] Effect of annealing and ion implantation on interlayer exchange coupling in Fe/Cr multilayersPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003T. Nowak Abstract Antiferromagnetic interlayer coupling in layered structures exhibiting giant magnetoresistance (GMR) is frequently destroyed by pinholes in the nonmagnetic layers. Therefore pinholes play a key role in limiting performance of GMR structures or magnetic tunnel junctions. We report temperature measurements of magnetization reversal in annealed and ion beam mixed [Fe-3.0 nm/Cr-1.1 nm] multilayers. Analysis of the experimental data shows that both annealing and ion mixing lead to similar subtle changes in the layered structure related to creating pinholes, changes in their density and average volume. [source] Pattern of geographical variation in petal shape in wild populations of Primula sieboldii E. MorrenPLANT SPECIES BIOLOGY, Issue 2 2007YOSUKE YOSHIOKA Abstract The petal shape of Primula sieboldii E. Morren (Primulaceae) is diverse in wild populations. In this study, we investigated population differentiation in the petal shape of P. sieboldii using image analysis. Flowers were sampled from 160 genets from eight wild populations in the western to north-eastern parts of the Japanese archipelago. Principal component (PC) analysis of 40 coefficients of elliptic Fourier descriptors (EFDs) detected three major characteristics of petal shape variation: the ratio of length to width (PC1), the depth of the head notch (PC2) and the position of the center of gravity (PC3). To test the association between divergence in petal shape and geographical and genetic distances, we calculated two types of pairwise population distances for petal shape: Mahalanobis distances for the 40 EFD coefficients and for the first three PCs. The existence of an association between neutral genetic markers and petal shape was revealed by the Mahalanobis distances based on the 40 EFD coefficients, suggesting that evolutionary forces, such as founder effect and isolation by distance effect, are probably the main causes of differentiation in petal shape. In contrast, we found no association between Mahalanobis distances for the first three PCs and geographical and genetic distances. The discrepancy between the two petal shape distances indicated that the population differentiation promoted by the founder effects and isolation by distance effect appears mainly as subtle changes in petal shape rather than in major characteristics of petal shape variation. [source] A quantitative strategy to detect changes in accessibility of protein regions to chemical modification on heterodimerizationPROTEIN SCIENCE, Issue 7 2009Mathias Dreger Abstract We describe a method for studying quantitative changes in accessibility of surface lysine residues of the PB1 subunit of the influenza RNA polymerase as a result of association with the PA subunit to form a PB1-PA heterodimer. Our method combines two established methods: (i) the chemical modification of surface lysine residues of native proteins by N -hydroxysuccinimidobiotin (NHS-biotin) and (ii) the stable isotope labeling of amino acids in cell culture (SILAC) followed by tryptic digestion and mass spectrometry. By linking the chemical modification with the SILAC methodology for the first time, we obtain quantitative data on chemical modification allowing subtle changes in accessibility to be described. Five regions in the PB1 monomer showed altered reactivity to NHS-biotin when compared with the [PB1-PA] heterodimer. Mutational analysis of residues in two such regions,at K265 and K481 of PB1, which were about three- and twofold, respectively, less accessible to biotinylation in the PB1-PA heterodimer compared with the PB1 monomer, demonstrated that both K265 and K481 were crucial for polymerase function. This novel assay of quantitative profiling of biotinylation patterns (Q-POP assay) highlights likely conformational changes at important functional sites, as observed here for PB1, and may provide information on protein,protein interaction interfaces. The Q-POP assay should be a generally applicable approach and may detect novel functional sites suitable for targeting by drugs. [source] Distinguishing multiple chemotaxis Y protein conformations with laser-polarized 129Xe NMRPROTEIN SCIENCE, Issue 4 2005Thomas J. Lowery Abstract The chemical shift of the 129Xe NMR signal has been shown to be extremely sensitive to the local environment around the atom and has been used to follow processes such as ligand binding by bacterial periplasmic binding proteins. Here we show that the 129Xe shift can sense more subtle changes: magnesium binding, BeF3, activation, and peptide binding by the Escherichia coli chemotaxis Y protein. 1H- 15N correlation spectroscopy and X-ray crystallography were used to identify two xenon-binding cavities in CheY that are primarily responsible for the shift changes. One site is near the active site, and the other is near the peptide binding site. [source] A statistically derived parameterization for the collagen triple-helixPROTEIN SCIENCE, Issue 11 2002Jan K. Rainey Abstract The triple-helix is a unique secondary structural motif found primarily within the collagens. In collagen, it is a homo- or hetero-tripeptide with a repeating primary sequence of (Gly-X-Y)n, displaying characteristic peptide backbone dihedral angles. Studies of bulk collagen fibrils indicate that the triple-helix must be a highly repetitive secondary structure, with very specific constraints. Primary sequence analysis shows that most collagen molecules are primarily triple-helical; however, no high-resolution structure of any entire protein is yet available. Given the drastic morphological differences in self-assembled collagen structures with subtle changes in assembly conditions, a detailed knowledge of the relative locations of charged and sterically bulky residues in collagen is desirable. Its repetitive primary sequence and highly conserved secondary structure make collagen, and the triple-helix in general, an ideal candidate for a general parameterization for prediction of residue locations and for the use of a helical wheel in the prediction of residue orientation. Herein, a statistical analysis of the currently available high-resolution X-ray crystal structures of model triple-helical peptides is performed to produce an experimentally based parameter set for predicting peptide backbone and C, atom locations for the triple-helix. Unlike existing homology models, this allows easy prediction of an entire triple-helix structure based on all existing high-resolution triple-helix structures, rather than only on a single structure or on idealized parameters. Furthermore, regional differences based on the helical propensity of residues may be readily incorporated. The parameter set is validated in terms of the predicted bond lengths, backbone dihedral angles, and interchain hydrogen bonding. [source] The murder of Buondelmonte: contesting place in early fourteenth-century Florentine chroniclesRENAISSANCE STUDIES, Issue 4 2006N. P. J. Gordon In 1215 a young nobleman was murdered in a vendetta at the foot of the Ponte Vecchio. The tale captured the Florentine imagination and the place of his death was immortalised. In the first half of the fourteenth century, however, the tale undergoes a number of subtle changes in the chronicles of Pseudo-Latini, Dino Compagni, and Giovanni Villani. These changes altered the meanings of the story and, consequently, affected the values tied to the place where the story was set. In this respect, each version can be read as an attempt to attack or legitimize a civic identity associated with Buondelmonte and the entry to the old city where he was murdered. [source] | |||||||||||||||||||||||||||||||||||||