52 research outputs found

    CUDA-GR: Controllable Unsupervised Domain Adaptation for Gaze Redirection

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    The aim of gaze redirection is to manipulate the gaze in an image to the desired direction. However, existing methods are inadequate in generating perceptually reasonable images. Advancement in generative adversarial networks has shown excellent results in generating photo-realistic images. Though, they still lack the ability to provide finer control over different image attributes. To enable such fine-tuned control, one needs to obtain ground truth annotations for the training data which can be very expensive. In this paper, we propose an unsupervised domain adaptation framework, called CUDA-GR, that learns to disentangle gaze representations from the labeled source domain and transfers them to an unlabeled target domain. Our method enables fine-grained control over gaze directions while preserving the appearance information of the person. We show that the generated image-labels pairs in the target domain are effective in knowledge transfer and can boost the performance of the downstream tasks. Extensive experiments on the benchmarking datasets show that the proposed method can outperform state-of-the-art techniques in both quantitative and qualitative evaluation

    Hystera Ektomia: not always called for

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    Unsympathetic hysterectomies have seen a rising trend in India in the recent times, the unsuspecting folks being pushed into surgeries wrongly citing the austerity of the illness. We highlight a case of a 26 year old female patient with post-partum bleeding per vaginum for 6 months, who was initially treated conservatively at several hospitals. Later, histopathologically proven to be a case of Choriocarcinoma (WHO Stage I with FIGO prognostic score of 5), was hysterectomized hastily overlooking the reports and the patient discharged without further intervention. Few months later the patient presented with brain and lungs metastases. Had the patient been properly evaluated and treated appropriately initially, surgery was not indicated. Instead the patient was callously operated upon and histopathological report not followed which resulted in patient developing distant metastases (WHO Stage IV with FIGO prognostic score of 17). Unwarranted and unevaluated hysterectomies should be checked by appropriately evaluating the extent of the disease.

    3D printed composite materials for craniofacial implants: current concepts, challenges and future directions

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    Millions of craniofacial surgeries are performed annually worldwide for craniofacial bones’ replacement and augmentation. This represents a significant economic burden as well as aesthetic expectations. Autografts and allografts are the first choice for treatment of craniofacial defects; however, their limited availability and difficulty to shape have led to investigation for alternative strategies. Biomaterial-based approaches have been used for implantation as they have ample supply but their processing through conventional technologies present several drawbacks; the major one relates to the poor versatility towards the production of patient-specific implants. Additive manufacturing has gained considerable attention during the last decade, as it allows the manufacturing of implants according to patient need. Biomaterial implants can be additively manufactured but have one or more limitations of stress shielding, radiopacity, high strength to weight ratio and limited bone integration. Over the last few decades, composites are investigated to surmount the limitations with traditional implants and also improve their bone integration. This review provides an overview of the most recent polymeric composite-based biomaterials that have been used in combination with 3D printing technology for the development of patient-specific craniofacial implants. Starting with the conventional treatments, biomaterials available for the craniofacial implants, the additive manufacturing rationale are discussed. Also, the main challenges still associated with 3D printing of polymer-based composites are critically reviewed and the future perspective presented

    Nano Structured Reduced Graphene Oxide (RGO) Coated TiO2 as Negative Electrode Additive for Advanced Lead acid Batteries

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    Lead-acid batteries(LABs)remains to be the most successful energy storage systems ever developed. Although lead-acid battery designs have been optimized in the past in several different ways, there are still certain challenges facing lead-acid battery designers, such as grid corrosion at the positive electrode, sulfation at both the electrodes, and poor charge acceptance of positive electrode, larger curing and formation time and more significantly low energy density because of high atomic weight of lead. So the current research efforts in electrochemical energy storage are directed towards achieving high energy density with reduced cost and less weight and reduce sulation. To overcome the issues of sulfation and formation efficiency of the electrodes we propose here reduced graphene oxide (RGO)coated TiO2 as a negative electrode additive for advanced Lead Acid Batteries(LAB). Addition of 0.5 wt. % of RGO coated TiO2 in to the negative active mass reduces sulfation, consequently increase battery formation efficiency from 3 cycle to 1 cycle, 10-20% increase in discharge capacity (C-rate performances). The additive also increases the battery life under high rate discharge conditions

    Additively Manufactured Ferroelectric Particulate Composites for Antimicrobial Applications

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    A polarized ferroelectric material can initiate the micro-electrolysis of water molecules which leads to the formation of reactive oxygen species (ROS) in an aqueous solution resulting in selective bacteria killing. This study presents the fabrication, characterization, and antimicrobial performance of poled ferroelectric particulate composites. Barium calcium zirconate titanate (BCZT) micro-powder is synthesized by a solid-state reaction and mechanically mixed with polycaprolactone (PCL) to be subsequently fed into the 3D bioprinter for the fabrication of porous PCL-BCZT structures at four different ceramic loadings (0, 10, 20, 30 wt%). For the examination of material's capacity to handle extremely high contamination, the composites are exposed to a high inoculum of bacteria (Escherichia coli ATCC 25922) ≈70% of E. coli degradation is recorded at the end of 15 min without any external intervention. The surface selective bacterial degradation can be attributed to the generated reactive oxygen species, the large surface area of the porous samples and polymer matrix's hydrophobic nature, behavior which can be reflected in the composites with 30 wt% of BCZT loading exhibiting the best antimicrobial performance among the other state-of-the-art ferroelectrics. Overall, these results indicate that the poled composites have a great potential as antimicrobial materials and surfaces.</p

    3D printed PEEK/HA composites for bone tissue engineering applications: effect of material formulation on mechanical performance and bioactive potential

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    Polyetheretherketone (PEEK) is a biocompatible polymer widely used for biomedical applications. Because it is biologically inert, bioactive phases, such as nano-hydroxyapatite (HA), have been added to PEEK in order to improve its bioactivity. 3D printing (3DP) technologies are being increasingly used today to manufacture patient specific devices and implants. However, processing of PEEK is challenging due to its high melting point which is above 340 °C. In this study, PEEK-based filaments containing 10 wt% of pure nano-HA, strontium (Sr)- doped nano-HA and Zinc (Zn)-doped nano-HA were produced via hot-melt extrusion and subsequently 3D printed via fused deposition modelling (FDM), following an initial optimization process. The raw materials, extruded filaments and 3D printed samples were characterized in terms of physicochemical, thermal and morphological analysis. Moreover, the mechanical performance of 3D printed specimens was assessed via tensile tensing. Although an increase in the melting point and a reduction in crystallization temperature was observed with the addition of HA and doped HA to pure PEEK, there was no noticeable increase in the degree of crystallinity. Regarding the mechanical behavior, no significant differences were detected following the addition of the inorganic phases to the polymeric matrix, although a small reduction in the ultimate tensile strength (~14%) and Young's modulus (~5%) in PEEK/HA was observed in comparison to pure PEEK. Moreover, in vitro bioactivity of 3D printed samples was evaluated via a simulated body fluid immersion test for up to 28 days; the formation of apatite was observed on the surfaces of sample surfaces containing HA, SrHA and ZnHA. These results indicate the potential to produce bioactive, 3DP PEEK composites for challenging applications such as in craniofacial bone repair

    Persistencia de malezas gramíneas en cultivos de trigo del sudeste bonaerense

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    En la presente tesis se estudió la persistencia de especies poáceas en cultivos de trigo del sudeste de Buenos Aires. En dicha región, Avena fatua L. y Lolium multiflorum Lam. son las malezas poáceas más importantes, tanto por la dificultad de control como por sus efectos competitivos sobre el cultivo. A los efectos de cuantificar la persistencia de dichas especies, se estudió la composición de la comunidad de malezas en dos momentos del ciclo: preaplicación de herbicidas y precosecha. Individuos de ambas malezas fueron registrados en ambos momentos como consecuencia de “escapes” al control realizado con herbicidas, siendo A. fatua más constante que L. mutiflorum. Posteriormente, se estudiaron los procesos que definen la persistencia de ambas malezas. Los resultados obtenidos indican que el ajuste del momento de emergencia es jerárquicamente el factor más importante para explicar la persistencia de A. fatua. Se demostró que los modelos de germinación son diferentes según las semillas provengan de un lote agrícola o de una condición de no cultivo, siendo estas diferencias de naturaleza genética. Por otro lado, la variabilidad en la supervivencia a los herbicidas es el factor que mejor explica la persistencia de L. multiflorum, habiéndose documentado resistencia cruzada a los herbicidas inhibidores de la ALS, pyroxsulam, imazamox y flucarbazone, sin antecedentes previos en la región. Los índices de resistencia encontrados presentan variación con la temperatura ambiente en post-aplicación del herbicida, habiéndose registrado mayor resistencia con mayor temperatura. Además, se comprobó que los individuos resistentes presentan menor tiempo a floración que los susceptibles. Tal atributo puede significar una ventaja demográfica para dichas poblaciones. Queda así demostrada la persistencia de A. fatua y L. multiflorum durante el ciclo del cultivo más allá de las prácticas de control realizadas y la participación de dos procesos demográficos distintos (establecimiento y supervivencia) en dicha persistencia
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