Energy Based Split Vector Quantizer Employing Signal Representation in Multiple Transform Domains.

This invention relates to representation of one and multidimensional signal vectors in nonorgothonal domains and design of Vector Quantizers that can be chosen among these representations. There is presented a Vector Quantization technique in multiple nonorthogonal domains for both waveform and model based signal characterization. An iterative codebook accuracy enhancement algorithm, applicable to both waveform and model based Vector Quantization in multiple nonorthogonal domains, which yields further improvement in signal coding performance, is disclosed. Further, Vector Quantization in in nonorthogonal domains is applied to speech and exhibits clear performance improvements of reconstruction quality for the same bit rate compared to existing single domain Vector Quantization techniques. The technique disclosed herein can be easily extended to several other one and multidimensional signal classes

Self Designing Intelligent Signal Processing System capable of evolutional Learning for Classification/Recognition of One and Multidimensional Signals

A Self-Designing Intelligent Signal Processing System Capable of Evolutional Learning for Classification/Recognition of One and Multidimensional Signals is described which classifies data by an evolutionary learning environment that develops the features and algorithms that are best suited for the recognition problem under consideration. The System adaptively learns what data need to be extracted in order to recognize the given pattern with the least amount of processing. The System decides what features need to be selected for classification and/or recognition to fit a certain structure that leads to the least amount of processing according to the nature of the given data. The System disclosed herein is capable of recognizing an enormously large number of patterns with a high accuracy

School inputs, household substitution, and test scores

Empirical studies of the relationship between school inputs and test scores typically do not account for the fact that households will respond to changes in school inputs. This paper presents a dynamic household optimization model relating test scores to school and household inputs, and tests its predictions in two very different low-income country settings -- Zambia and India. The authors measure household spending changes and student test score gains in response to unanticipated as well as anticipated changes in school funding. Consistent with the optimization model, they find in both settings that households offset anticipated grants more than unanticipated grants. They also find that unanticipated school grants lead to significant improvements in student test scores but anticipated grants have no impact on test scores. The results suggest that naïve estimates of public education spending on learning outcomes that do not account for optimal household responses are likely to be considerably biased if used to estimate parameters of an education production function.Tertiary Education,Education For All,Access to Finance,Teaching and Learning,Disability

Incidence and management of incidental durotomy during thoracic and lumbar spine surgeries: a retrospective review in a tertiary care centre

Background: Incidental durotomy is among the most common complications of spine surgery with reported incidence ranging from 1.7% to 16%. Various management options including primary repair, fascial or fat graft, epidural blood patch, fibrin glue sealant, etc., have been proposed. The purpose of this study is to evaluate the incidence of incidental durotomy and the efficacy of different management options during a five year period at a tertiary care center.Methods: All patients who underwent various surgical procedures in thoracic and lumbar spine from January 2006 - December 2010 in our centre were retrospectively reviewed. Data on demographics, primary diagnosis, associated co morbidities, details of surgical procedure, training level of the operating surgeon, details of the incidental durotomy, the treatment, complications and the postoperative stay were recorded.Results: Of 2270 patients, 1401 patients were included in the study. The incidence of incidental durotomy was 3.49% (49 patients). We found a very high incidence of 33.33% incidental durotomies among patients who underwent revision procedures as compared to 3.23% for patients who underwent primary surgeries. 5.10% of incidental durotomies were caused by fellows under training, 4.27% by junior consultants and 2.92% by senior consultants. Of 49 durotomies, complication were 5 cases of intracranial hypotension, 5 postoperative neurological deficits, 2 deep wound infection, 2 pseudomeningocele and 1 meningitis.Conclusions: The risk of incidental durotomy in thoracolumbar surgeries is high in revision surgeries and when performed by fellows in training. Intraoperative identification and primary repair with suturing or sealant reduces postoperative complications

Testing Pullout Strength of Pedicle Screw Using Synthetic Bone Models: Is a Bilayer Foam Model a Better Representation of Vertebra?

Study Design A biomechanical study. Purpose A new biomechanical model of the vertebra has been developed that accounts for the inhomogeneity of bone and the contribution of the pedicle toward the holding strength of a pedicle screw. Overview of Literature Pullout strength studies are typically carried out on rigid polyurethane foams that represent the homogeneous vertebral framework of the spine. However, the contribution of the pedicle region, which contributes to the inhomogeneity in this framework, has not been considered in previous investigations. Therefore, we propose a new biomechanical model that can account for the vertebral inhomogeneity, especially the contribution of the pedicles toward the pullout strength of the pedicle screw. Methods A bilayer foam model was developed by joining two foams representing the pedicle and the vertebra. The results of the pullout strength tests performed on the foam models were compared with those from the tests performed on the cadaver lumbar vertebra. Results Significant differences (p 0.05) in the pullout strength of pedicle screws between osteoporotic (0.85±0.08 kN) and extremely osteoporotic bone models (0.94±0.08 kN), but there was a significant difference (p 0.05) in pullout strength between cadaver and bilayer foam model in normal bones. Conclusions The new synthetic bone model that reflects the contribution of the pedicles to the pullout strength of the pedicle screws could provide a more efficacious means of testing pedicle-screw pullout strength. The bilayer model can match the pullout strength value of normal lumbar vertebra bone whereas the monolayer foam model was able to match that of the extremely osteoporotic lumbar vertebra

Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

Study DesignBiomechanical study.PurposeTo determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations.Overview of LiteraturePedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically in osteoporotic bones.MethodsSingle screw and two screw pull-out strength tests were carried out according to American Society for Testing and Materials F 543-07 on foam models to test the effect of density, insertion angle and reinsertion using poly axial pedicle screws.ResultsBone density was the most significant factor deciding the pull-out strength in both single and two screw constructs. The difference in pull-out strength between single screw and two screw configurations in extremely osteoporotic bone model (80 kg/m3) was 78%, whereas in the normal bone model it was 48%. Axial pull-out value was highest for the single screw configuration; in the two screw configuration the highest pull-out strength was at 10°–15°. There was an 18% reduction in pull-out strength due to reinsertion in single screw configuration. The reinsertion effect was insignificant in the two screw configuration.ConclusionsA significant difference in response of various factors on holding power of pedicle screw between single and two-screw configurations is evident. The percentage increase in pull-out strength between single and two screw constructs is higher for osteoporotic bone when compared to normal bone. Reinsertion has no significant effect on pull-out strength in the two screw rod configuration

Acute fluid shifts influence the assessment of serum vitamin D status in critically ill patients

Recent reports have highlighted the prevalence of vitamin D deficiency and suggested an association with excess mortality in critically ill patients. Serum vitamin D concentrations in these studies were measured following resuscitation. It is unclear whether aggressive fluid resuscitation independently influences serum vitamin D.Nineteen patients undergoing cardiopulmonary bypass were studied. Serum 25(OH)D(3), 1α,25(OH)(2)D(3), parathyroid hormone, C-reactive protein (CRP), and ionised calcium were measured at five defined timepoints: T1 - baseline, T2 - 5 minutes after onset of cardiopulmonary bypass (CPB) (time of maximal fluid effect), T3 - on return to the intensive care unit, T4 - 24 hrs after surgery and T5 - 5 days after surgery. Linear mixed models were used to compare measures at T2-T5 with baseline measures.Acute fluid loading resulted in a 35% reduction in 25(OH)D(3) (59 ± 16 to 38 ± 14 nmol/L, P < 0.0001) and a 45% reduction in 1α,25(OH)(2)D(3) (99 ± 40 to 54 ± 22 pmol/L P < 0.0001) and i(Ca) (P < 0.01), with elevation in parathyroid hormone (P < 0.0001). Serum 25(OH)D(3) returned to baseline only at T5 while 1α,25(OH)(2)D(3) demonstrated an overshoot above baseline at T5 (P < 0.0001). There was a delayed rise in CRP at T4 and T5; this was not associated with a reduction in vitamin D levels at these time points.Hemodilution significantly lowers serum 25(OH)D(3) and 1α,25(OH)(2)D(3), which may take up to 24 hours to resolve. Moreover, delayed overshoot of 1α,25(OH)(2)D(3) needs consideration. We urge caution in interpreting serum vitamin D in critically ill patients in the context of major resuscitation, and would advocate repeating the measurement once the effects of the resuscitation have abated

School Inputs, Household Substitution, and Test Scores

Empirical studies of the relationship between school inputs and test scores typically do not account for the fact that households will respond to changes in school inputs. We present a dynamic household optimization model relating test scores to school and household inputs, and test its predictions in two very different low-income country settings – Zambia and India. We measure household spending changes and student test score gains in response to unanticipated as well as anticipated changes in school funding. Consistent with the optimization model, we find in both settings that households offset anticipated grants more than unanticipated grants. We also find that unanticipated school grants lead to significant improvements in student test scores but anticipated grants have no impact on test scores. Our results suggest that naïve estimates of public education spending on learning outcomes that do not account for optimal household responses are likely to be considerably biased if used to estimate parameters of an education production function.

Changes in Cytokines of the Bone Microenvironment during Breast Cancer Metastasis

It is commonly accepted that cancer cells interact with host cells to create a microenvironment favoring malignant colonization. The complex bone microenvironment produces an ever changing array of cytokines and growth factors. In this study, we examined levels of MCP-1, IL-6, KC, MIP-2, VEGF, MIG, and eotaxin in femurs of athymic nude mice inoculated via intracardiac injection with MDA-MB-231GFP human metastatic breast cancer cells, MDA-MB-231BRMS1GFP, a metastasis suppressed variant, or PBS. Animals were euthanized (day 3, 11, 19, 27 after injection) to examine femoral cytokine levels at various stages of cancer cell colonization. The epiphysis contained significantly more cytokines than the diaphysis except for MIG which was similar throughout the bone. Variation among femurs was evident within all groups. By day 27, MCP-1, MIG, VEGF and eotaxin levels were significantly greater in femurs of cancer cell-inoculated mice. These pro-osteoclastic and angiogenic cytokines may manipulate the bone microenvironment to enhance cancer cell colonization

CD24 signalling through macrophage Siglec-10 is a target for cancer immunotherapy.

Ovarian cancer and triple-negative breast cancer are among the most lethal diseases affecting women, with few targeted therapies and high rates of metastasis. Cancer cells are capable of evading clearance by macrophages through the overexpression of anti-phagocytic surface proteins called 'don't eat me' signals-including CD471, programmed cell death ligand 1 (PD-L1)2 and the beta-2 microglobulin subunit of the major histocompatibility class I complex (B2M)3. Monoclonal antibodies that antagonize the interaction of 'don't eat me' signals with their macrophage-expressed receptors have demonstrated therapeutic potential in several cancers4,5. However, variability in the magnitude and durability of the response to these agents has suggested the presence of additional, as yet unknown 'don't eat me' signals. Here we show that CD24 can be the dominant innate immune checkpoint in ovarian cancer and breast cancer, and is a promising target for cancer immunotherapy. We demonstrate a role for tumour-expressed CD24 in promoting immune evasion through its interaction with the inhibitory receptor sialic-acid-binding Ig-like lectin 10 (Siglec-10), which is expressed by tumour-associated macrophages. We find that many tumours overexpress CD24 and that tumour-associated macrophages express high levels of Siglec-10. Genetic ablation of either CD24 or Siglec-10, as well as blockade of the CD24-Siglec-10 interaction using monoclonal antibodies, robustly augment the phagocytosis of all CD24-expressing human tumours that we tested. Genetic ablation and therapeutic blockade of CD24 resulted in a macrophage-dependent reduction of tumour growth in vivo and an increase in survival time. These data reveal CD24 as a highly expressed, anti-phagocytic signal in several cancers and demonstrate the therapeutic potential for CD24 blockade in cancer immunotherapy