29,374 research outputs found

    Search efficiency as a function of target saliency: The transition from inefficient to efficient search and beyond.

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    Searching for an object among distracting objects is a common daily task. These searches differ in efficiency. Some are so difficult that each object must be inspected in turn, whereas others are so easy that the target object directly catches the observer’s eye. In 4 experiments, the difficulty of searching for an orientation-defined target was parametrically manipulated between blocks of trials via the target–distractor orientation contrast. We observed a smooth transition from inefficient to efficient search with increasing orientation contrast. When contrast was high, search slopes were flat (indicating pop-out); when contrast was low, slopes were steep (indicating serial search). At the transition from inefficient to efficient search, search slopes were flat for target-present trials and steep for target-absent trials within the same orientation-contrast block—suggesting that participants adapted their behavior on target-absent trials to the most difficult, rather than the average, target-present trials of each block. Furthermore, even when search slopes were flat, indicative of pop-out, search continued to become faster with increasing contrast. These observations provide several new constraints for models of visual search and indicate that differences between search tasks that were traditionally considered qualitative in nature might actually be due to purely quantitative differences in target discriminability. (PsycINFO Database Record (c) 2016 APA, all rights reserved

    One bath method dyeing of polyester/cotton blend fabric with sulphatoethylsulphonyl disperse/reactive dyes treatment by chitin biopolymer

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    In this research, the process of dyeing polyester/cotton fabrics using disperse/reactive dyestuffs in one method dyeing processes was investigated. In the order to improve the adhesion of chitin to the surface of polyester/cotton fibers, pre-treatment in NaOH solutions was performed. The colour and rubbing fastness properties of the chitin-deposited polyester/cotton fabrics were assessed. The colour difference between the dyed blank samples and samples dyed in NaOH and/or different viscosity chitin treatment was estimated. The data obtained shows that it is possible to dye polyester/cotton fabrics finished by chitin with only one disperses/reactive dyestuff. The dyed samples showed good rubbing andwashing colour fastness properties within the range of colour change. The colour strength of the dyed samples increased with the increased deposition of chitin on the fabric

    Effects of fluid-rock interaction on Ar-40/Ar-39 geochronology in high-pressure rocks (Sesia-Lanzo Zone, Western Alps)

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    In situ UV laser spot 40Ar/39Ar analyses of distinct phengite types in eclogite-facies rocks from the Sesia-Lanzo Zone (Western Alps, Italy) were combined with SIMS boron isotope analyses as well as boron (B) and lithium (Li) concentration data to link geochronological information with constraints on fluid–rock interaction. In weakly deformed samples, apparent 40Ar/39Ar ages of phengite cores span a range of ∼20 Ma, but inverse isochrons define two distinct main high-pressure (HP) phengite core crystallization periods of 88–82 and 77–74 Ma, respectively. The younger cores have on average lower B contents (∼36 μg/g) than the older ones (∼43–48 μg/g), suggesting that loss of B and resetting of the Ar isotopic system were related. Phengite cores have variable δ11B values (−18‰ to −10‰), indicating the lack of km scale B homogenization during HP crystallization. Overprinted phengite rims in the weakly deformed samples generally yield younger apparent 40Ar/39Ar ages than the respective cores. They also show variable effects of heterogeneous excess 40Ar incorporation and Ar loss. One acceptable inverse isochron age of 77.1 ± 1.1 Ma for rims surrounding older cores (82.6 ± 0.6 Ma) overlaps with the second period of core crystallization. Compared to the phengite cores, all rims have lower B and Li abundances but similar δ11B values (−15‰ to −9‰), reflecting internal redistribution of B and Li and internal fluid buffering of the B isotopic composition during rim growth. The combined observation of younger 40Ar/39Ar ages and boron loss, yielding comparable values of both parameters only in cores and rims of different samples, is best explained by a selective metasomatic overprint. In low permeability samples, this overprint caused recrystallization of phengite rims, whereas higher permeability in other samples led to complete recrystallization of phengite grains. Strongly deformed samples from a several km long, blueschist-facies shear zone contain mylonitic phengite that forms a tightly clustered group of relatively young apparent 40Ar/39Ar ages (64.7–68.8 Ma), yielding an inverse isochron age of 65.0 ± 3.0 Ma. Almost complete B and Li removal in mylonitic phengite is due to leaching into a fluid. The B isotopic composition is significantly heavier than in phengites from the weakly deformed samples, indicating an external control by a high-δ11B fluid (δ11B = +7 ± 4‰). We interpret this result as reflecting phengite recrystallization related to deformation and associated fluid flow in the shear zone. This event also caused partial resetting of the Ar isotope system and further B loss in more permeable rocks of the adjacent unit. We conclude that geochemical evidence for pervasive or limited fluid flow is crucial for the interpretation of 40Ar/39Ar data in partially metasomatized rocks

    NEXP-completeness and Universal Hardness Results for Justification Logic

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    We provide a lower complexity bound for the satisfiability problem of a multi-agent justification logic, establishing that the general NEXP upper bound from our previous work is tight. We then use a simple modification of the corresponding reduction to prove that satisfiability for all multi-agent justification logics from there is hard for the Sigma 2 p class of the second level of the polynomial hierarchy - given certain reasonable conditions. Our methods improve on these required conditions for the same lower bound for the single-agent justification logics, proven by Buss and Kuznets in 2009, thus answering one of their open questions.Comment: Shorter version has been accepted for publication by CSR 201

    Case Report of Advanced Childhood Nasopharyngeal Carcinoma: Is Radiotherapy Dose Deescalation the Right Way in Good Responders to Induction Chemotherapy

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    Objectives:. Treatment of childhood NPC similar to adults consists of radiotherapy and chemotherapy, but distant failure is often observed, which led to introducing the induction chemotherapy followed by radiation or chemoradiation. The improved survival rates raised the question of late toxicity. The options for lowering the toxicity rate is the application of advanced radiotherapy techniques like IMRT and VMAT, and deescalation of the radiation dose in good responders and early NPC.Case report: We report a case of13-years old male patient with a high-risk childhood undifferentiated NPC, stage cT4 cN2b M0. He presented with unilateral swallowing at the middle third of left muscle sterenocleidomastoideus, and headache, fever, sore throat and intermittent nasal bleeding for an year. Diagnostic MRI and PET/CT showed good concordance for primary tumor extension and lymph node involvement. Three coursesinduction chemotherapy were applied according to NPC2003-GPOH protocolwith good treatment response. The restaging PET/CT found no distant metastasis. Deescalated protocol of radiotherapy alone was delivered to 50.4 Gy total dose with IGRT, VMAT irradiation technique. At three month PET/CT follow up a solitary bone lesion was detected.Conclusion: The present case proved that in high risk patients more aggressive treatment strategies should be recommended with no omission of concurrent chemotherapy even after full response. Deescalation of radiotherapy dose probably is not appropriate in this group of patients. MRI and PET CT should be used as complementary imaging modalities for early detection of locoregional or distant metastasis

    Clinical improvement and radiological progression in a girl with early onset scoliosis (EOS) treated conservatively – a case report

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    BACKGROUND: Chêneau-Brace treatment of a certain standard reduces the rate of surgery, prevents progression and in a certain patient population leads to marked improvement of Cobb angle and cosmetic appearance. During the last two years a patient refusing surgery with a double major curvature of initially 60° showed a clear cosmetic improvement and a clear radiological progression at the same time. The findings of this patient have been reviewed in order to find out how cosmetic appearance and Cobb angle can develop differently. METHODS: The patient entered conservative treatment at the age of 13 years, premenarchial with Tanner II and a Cobb angle of 60° thoracic and 59° lumbar. The angle of trunk rotation (ATR; Scoliometer) was 13° thoracic and 13° lumbar. We have documented the findings of this patient (Surface topography, ATR, Cobb angles and angles of vertebral rotation (according to Raimondi) during the treatment period (27 Month) until 2 years after the onset of menarche. RESULTS: After a treatment time of 27 Month the Cobb angle increased to 74° thoracic and 65° lumbar. The angles of vertebral rotation according to Raimondi increased slightly from 26° thoracic and 28° lumbar to 30° thoracic and 28° lumbar. The ATR improved to 12° thoracic and 5° lumbar while Lateral deviation improved from 22,4 mm to 4,6 mm and average surface rotation improved from 10,6° to 6°. In the X-rays a reduction of decompensation was visible. The patient felt comfortable with the cosmetic result. CONCLUSION: Conservative treatment may improve cosmetic appearance while the curve progresses radiologically. This could be explained by assuming that (1) the Rigo Chêneau brace is able to improve cosmetic appearance by changing the shape of the thorax when the curve itself is too stiff to be corrected by a brace, that (2) reduction of decompensation leads to significant cosmetical improvements or (3) that the patient gained weight and therefore the deformation is masked. However, the weight the patient gained cannot explain the cosmetical improvement in this case. Conservative treatment with a certain standard of quality seems a viable alternative for patients with Cobb angles of > 60° when surgical treatment is refused. Specialists in scoliosis management should be aware of the fact that curve progression can occur even if the clinical measurements show an improvement

    Clinical Effect of the Chinese Medicine Formula Supplementation on Metastatic Bone Tumor

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    Background. Metastatic bone tumor occurs when cancer cells from the original tumor area travel (or metastasize) via blood stream or/and lymphatic pathway. Metastatic bone lesions are common in cancer of the breast, lung, prostate, kidney, and thyroid. One of the main symptoms of bone cancer is bone pain, which can decrease the quality of life. At present, there is no cure for metastatic bone disease. Several studies suggest Chinese medicine formula have a good result in treating Malignancy. Materials and methods. Twelve participants, were given Chinese medicine formula which obtain from The Chinese University of Hong Kong, consume every day for 24 weeks. The clinical parameters include body weight, physical performance status(Karnofsky), and pain intensity. Those parameters were evaluated every 4 weeks, and the changes of those parameter after supplementation Chinese medicine formula were analyzed statistically. Results. Participants shows positive changes on these observed parameters after supplementation Chinese medicine formula. Paired t-test study, shows these changes are significant statistically (p<0.05). Conclusions. Supplementation Chinese medicine formula for metastatic bone tumor proved could give positive clinical effect by improving quality of life patients with metastatic bone tumor
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