188 research outputs found

    Unirationality of moduli spaces of special cubic fourfolds and K3 surfaces

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    We provide explicit descriptions of the generic members of Hassett's divisors Cd\mathcal C_d for relevant 18d3818\leq d\leq 38 and for d=44d=44. In doing so, we prove that Cd\mathcal C_d is unirational for 18d38,d=4418\leq d\leq 38,d=44. As a corollary, we prove that the moduli space Nd\mathcal N_{d} of polarized K3 surfaces of degree dd is unirational for d=14,26,38d=14,26,38. The case d=26d=26 is entirely new, while the other two cases have been previously proven by Mukai.Comment: 13 pages, 2 tables. Script for the computer calculations used are provided on the author's websit

    Analisis Faktor Yang Mempengaruhi Konsumen Dalam Pemakaian Produk Layanan Seluler Dengan Mempertimbangkan Aspek 7p\u27s of Marketing (Studi Kasus : PT. Telkom Area Blora)

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    Perkembangan dunia telekomunikasi yang semakin pesat dan ketatnya persaingan antar provider telepon seluler, membuat para produsen tidak gegabah dalam menentukan dan mengembangkan jenis produknya. Setelah kemunculan telepon seluler dengan teknologi AMPS (Advance Mobile Phone Systems) dan GSM (Global Systems for Mobile Communication), kemudian berkembang teknologi CDMA (Code Devision Multiple Acess). PT.Telekomunikasi Indonesia, Kancatel Blora sebagai penyedia layanan Telkom Flexi untuk wilayah Kabupaten Blora, menghadapi beberapa hal penting dalam memperkenalkan produknya. Nilai penjualan diharapkan untuk lebih berkembang lagi, namun harus menghadapi tantangan dari pesaing dengan produk baru yang inovatif. Untuk itu, TelkomFlexi mengambil tindakan dengan memberikan produk yang berkualitas, layanan yang baik dan fasilitas yang memadai bagi para penggunanya, akan tetapi pada Kenyataannya hingga sekarang ini jumlah pengguna Flexi wilayah Blora masih rendah jika dibanding dengan wilayah lain. Oleh karena itu, penelitian ini menganalisa faktor-faktor apa yang mempengaruhi preferensi konsumen diwilayah Blora dalam menggunakan suatu produk mobile communication. Penelitian ini menggunakan metode analisis faktor untuk mengetahui faktor-faktor apa yang mempengaruhi preferensi konsumen dalam menggunakan suatu produk mobile communication. Analisis faktor yaitu suatu metode reduksi data untuk menemukan variabel baru yang disebut faktor yang jumlahnya lebih sedikit dibandingkan dengan jumlah aslinya, yang tidak berkorelasi satu sama lainnya, variabel baru tersebut memuat sebanyak mungkin informasi yang terkandung di dalam variabel asli. Hasil analisis menunjukkan bahwa terdapat 9 faktor yang mempengaruhi preferensi konsumen dalam menggunakan suatu produk mobile communication, yaitu : faktor bukti fisik, faktor fitur tambahan produk, faktor proses, faktor harga, faktor karyawan, faktor kinerja inti produk, faktor promosi, faktor tampilan nyata produk, faktor lokasi. Atribut-atribut yang ada mengelompok sesuai dengan konsep 7P hanya saja untuk aspek produk, menurut hasil kuesioner dari responden lebih di spesifikasi secara detail menjadi kinerja inti produk, tampilan nyata produk, dan fitur tambahan produk. Kata Kunci : 7P, Analisis Faktor, Mobile Communication, Code Devision Multiple Acess (CDMA), Global System for Mobile (GSM) The development of the telecommunications world is increasingly rapid and intense competition among cell phone providers, the producers do not make hasty in determining and developing types of products. After the emergence of cellular phone technology, AMPS (Advanced Mobile Phone Systems) and GSM (Global Systems for Mobile Communication), then developing CDMA technology (Code Devision Multiple acess). PT.Telekomunikasi Indonesia, Kancatel Blora as Telkom Flexi service provider for Blora Regency, facing some important things in introducing products. Value sales are expected to further expand again, but must face challenges from competitors with innovative new products. For that, TelkomFlexi take action by providing quality products, good service and adequate facilities for its users, but in fact to this day the number of users Flexi Blora region is still low when compared with other regions (Rembang and Purwodadi). Therefore, this study analyzes factors that affect consumer preferences in the region Blora using a mobile communication products. This study uses factor analysis method to determine what factors are influencing consumer preferences in the use of a mobile communication products. Factor analysis is a data reduction method for finding a new variable called factor fewer than the original amount, which does not correlate with each other, the new variables contain most of the information contained in the original variables. The results of the analysis show that there are 9 factors that influence consumer preferences in the use of a mobile communication products, namely: physical evidence factor, product enhancement factor, process factor, price factor, the employee factor, performance factor of the core product, promotion factor, factor real view product , the location factor. Attributes are grouped in accordance with the concept 7P only to aspects of the product, according to the results of questionnaires from respondents over the specifications in detail. The performance of the core product, tangible display products, and additional features of the product

    Plasmodium malariae and Plasmodium ovale infections and their association with common red blood cell polymorphisms in a highly endemic area of Uganda.

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    BACKGROUND: Plasmodium ovale and Plasmodium malariae infections are scarcely studied in sub-Saharan Africa, where the Plasmodium falciparum species predominates. The objective of this study is to investigate the prevalence of P. ovale and P. malariae infections and their relationship with common red blood cell polymorphisms in a cohort of 509 individuals from Uganda. METHODS: Three cross-sectional surveys were conducted in individuals of 1-10 and >20 y of age from the Apac district at baseline and 6 and 16 weeks after drug treatment. Malaria infections were assessed by polymerase chain reaction and genotyping was performed for the sickle-cell allele, α-thalassaemia and glucose-6-phosphate dehydrogenase. RESULTS: At baseline, the prevalence of infection was 7.5%, 12.6% and 57.4% for P. ovale, P. malariae and P. falciparum species, respectively. Co-infections were present in 14.1% of individuals, all including P. falciparum parasites. In children 1-5 y of age, the prevalence of P. ovale mono-infections increased significantly from 1.7% to 7.3% over time (p=0.004) while the prevalence of P. malariae and P. falciparum infections declined significantly during this study. After adjusting for confounding and multiple testing, only α-thalassaemia had a statistically significant increase in the odds of P. falciparum infections (odds ratio 1.93 [95% confidence interval 1.26 to 2.94]). CONCLUSIONS: Common red blood cell polymorphisms do not show strong effects on mild Plasmodium infections in this Ugandan population. To understand the extent of this result, similar studies should be carried out in other populations using larger cohorts

    Early appearance of nonvisual and circadian markers in the developing inner retinal cells of chicken.

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    The retina is a key component of the vertebrate circadian system; it is responsible for detecting and transmitting the environmental illumination conditions (day/night cycles) to the brain that synchronize the circadian clock located in the suprachiasmatic nucleus (SCN). For this, retinal ganglion cells (RGCs) project to the SCN and other nonvisual areas. In the chicken, intrinsically photosensitive RGCs (ipRGCs) expressing the photopigment melanopsin (Opn4) transmit photic information and regulate diverse nonvisual tasks. In nonmammalian vertebrates, two genes encode Opn4: the Xenopus (Opn4x) and the mammalian (Opn4m) orthologs. RGCs express both Opn4 genes but are not the only inner retinal cells expressing Opn4x: horizontal cells (HCs) also do so. Here, we further characterize primary cultures of both populations of inner retinal cells (RGCs and HCs) expressing Opn4x. The expression of this nonvisual photopigment, as well as that for different circadian markers such as the clock genes Bmal1, Clock, Per2, and Cry1, and the key melatonin synthesizing enzyme, arylalkylamine N-acetyltransferase (AA-NAT), appears very early in development in both cell populations. The results clearly suggest that nonvisual Opn4 photoreceptors and endogenous clocks converge all together in these inner retinal cells at early developmental stages.journal articleresearch support, non-u.s. gov't20142014 05 20importe

    Defining the optimal dose of radiation in leukemic patients with extramedullary lesions

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    <p>Abstract</p> <p>Background</p> <p>Analysis of the clinical response of extramedullary lesions in leukemic patients treated with radiation therapy (RT) and defining the optimal dose of radiation.</p> <p>Methods</p> <p>Forty-two extramedullary lesions found in 24 leukemic patients treated with RT were reviewed. The radiation was delivered usually 2 Gy/day, up to a median of 20 Gy (range: 18.0-40.8). The clinical response and symptom palliation effect were analyzed. The factors affecting the response were also included in the analysis.</p> <p>Results</p> <p>After a median time of 7.9 weeks, the overall response rate was 76.2%. A complete response (CR) was achieved in 35.7%, a partial response in 40.5%. The symptom was relieved in 85.7% sites. The overall response rate was better in patients whose initial tumor size was smaller than 10 cm<sup>2 </sup>(<it>p = 0.010</it>) or who were treated with more than 25 Gy (<it>p = 0.031</it>). The overall CR rate was also higher in those who had smaller tumors (smaller than 6 cm or 30 cm<sup>2</sup>) (<it>p = 0.015)</it>, or when the tumor was located in soft tissue (<it>p = 0.029</it>).</p> <p>Conclusions</p> <p>Extramedullary lesions in leukemic patients can be successfully treated with RT. The tumor response rate was excellent and symptom relief was achieved in almost all patients. There was a better response to treatment when the tumor was small or it was located in soft tissue. Although, there was no definite correlation between volume reduction and total dose, it seems that higher total dose more of than 25 Gy is needed for better response.</p

    On the Picard group of Enriques surfaces

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46224/1/208_2005_Article_BF01456135.pd

    Haemoglobin C and S Role in Acquired Immunity against Plasmodium falciparum Malaria

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    A recently proposed mechanism of protection for haemoglobin C (HbC; β6Glu→Lys) links an abnormal display of PfEMP1, an antigen involved in malaria pathogenesis, on the surface of HbC infected erythrocytes together with the observation of reduced cytoadhesion of parasitized erythrocytes and impaired rosetting in vitro. We investigated the impact of this hypothesis on the development of acquired immunity against Plasmodium falciparum variant surface antigens (VSA) encoding PfEMP1 in HbC in comparison with HbA and HbS carriers of Burkina Faso. We measured: i) total IgG against a single VSA, A4U, and against a panel of VSA from severe malaria cases in human sera from urban and rural areas of Burkina Faso of different haemoglobin genotypes (CC, AC, AS, SC, SS); ii) total IgG against recombinant proteins of P. falciparum asexual sporozoite, blood stage antigens, and parasite schizont extract; iii) total IgG against tetanus toxoid. Results showed that the reported abnormal cell-surface display of PfEMP1 on HbC infected erythrocytes observed in vitro is not associated to lower anti- PfEMP1 response in vivo. Higher immune response against the VSA panel and malaria antigens were observed in all adaptive genotypes containing at least one allelic variant HbC or HbS in the low transmission urban area whereas no differences were detected in the high transmission rural area. In both contexts the response against tetanus toxoid was not influenced by the β-globin genotype. These findings suggest that both HbC and HbS affect the early development of naturally acquired immunity against malaria. The enhanced immune reactivity in both HbC and HbS carriers supports the hypothesis that the protection against malaria of these adaptive genotypes might be at least partially mediated by acquired immunity against malaria

    Perioperative immunomodulation with interleukin-2 in patients with renal cell carcinoma: results of a controlled phase II trial

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    We conducted a non-randomised controlled phase II trial to investigate the role of preoperative administration of interleukin-2 (IL-2) in patients with renal cell carcinoma undergoing tumour nephrectomy. A total of 120 consecutive patients were allocated alternately to the two study groups: perioperative immunomodulation with IL-2 (IL-2 group; n=60) and perioperative immunomonitoring without immunomodulation (control group; n=60). Patients from the IL-2 group received four doses of 10 × 106 IU m−2 twice daily subcutaneously a week before operation followed by a daily maintenance dose of 3 × 106 IU m−2 subcutaneously until a day before the operation. Parameters of cellular and humoral immunity (leucocytes, T-cell markers CD3, CD4, and CD8, B-cell marker CD19, monocyte marker CD14, natural killer (NK) cell markers CD16, CD56, and CD57, activation markers CD6, CD25, CD28, and CD69, progenitor cell marker CD34, as well as IL-2, IL-6, IL-10, soluble IL-2 receptor, IL-1 receptor antagonist, transforming growth factor-β1, and vascular endothelial growth factor) were measured in peripheral venous blood at various intervals. Interleukin-2-related toxicity was WHO grade 1 (24%), 2 (67%), and 3 (9%). In the postoperative period, T-cell markers, activation markers, and NK cell markers decreased, and IL-6 and IL-10 increased. However, all these alterations were significantly less accentuated in patients who had been pretreated with IL-2. Median follow-up was 40 months. Tumour-specific survival in the IL-2 group and the control group was 98 vs 81% after 1 year and 86 vs 73% after 5 years (P=0.04). A similar effect was found for progression-free survival. We conclude that IL-2 can be safely administered in the perioperative period and modulates immunological parameters. However, to validate the survival data, a larger randomised phase III trial is needed

    Characterization of immunoglobulin G antibodies to Plasmodium falciparum sporozoite surface antigen MB2 in malaria exposed individuals

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    <p>Abstract</p> <p>Background</p> <p>MB2 protein is a sporozoite surface antigen on the human malaria parasite <it>Plasmodium falciparum</it>. MB2 was identified by screening a <it>P. falciparum </it>sporozoite cDNA expression library using immune sera from a protected donor immunized via the bites of <it>P. falciparum</it>-infected irradiated mosquitoes. It is not known whether natural exposure to <it>P. falciparum </it>also induces the anti-MB2 response and if this response differs from that in protected individuals immunized via the bites of <it>P. falciparum </it>infected irradiated mosquitoes. The anti-MB2 antibody response may be part of a robust protective response against the sporozoite.</p> <p>Methods</p> <p>Fragments of polypeptide regions of MB2 were constructed as recombinant fusions sandwiched between glutathione S-transferase and a hexa histidine tag for bacterial expression. The hexa histidine tag affinity purified proteins were used to immunize rabbits and the polyclonal sera evaluated in an <it>in vitro </it>inhibition of sporozoite invasion assay. The proteins were also used in immunoblots with sera from a limited number of donors immunized via the bites of <it>P. falciparum </it>infected irradiated mosquitoes and plasma and serum obtained from naturally exposed individuals in Kenya.</p> <p>Results</p> <p>Rabbit polyclonal antibodies targeting the non-repeat region of the basic domain of MB2 inhibited sporozoites entry into HepG2-A16 cells <it>in vitro</it>. Analysis of serum from five human volunteers that were immunized via the bites of <it>P. falciparum </it>infected irradiated mosquitoes that developed immunity and were completely protected against subsequent challenge with non-irradiated parasite also had detectable levels of antibody against MB2 basic domain. In contrast, in three volunteers not protected, anti-MB2 antibodies were below the level of detection. Sera from protected volunteers preferentially recognized a non-repeat region of the basic domain of MB2, whereas plasma from naturally-infected individuals also had antibodies that recognize regions of MB2 that contain a repeat motif in immunoblots. Sequence analysis of eleven field isolates and four laboratory strains showed that these antigenic regions of the basic domain of the <it>MB2 </it>gene are highly conserved in parasites obtained from different parts of the world. Moreover, anti-MB2 antibodies also were detected in the plasma of 83% of the individuals living in a malaria endemic area of Kenya (n = 41).</p> <p>Conclusion</p> <p>A preliminary analysis of the human humoral response against MB2 indicates that it may be an additional highly conserved target for immune intervention at the pre-erythrocytic stage of <it>P. falciparum </it>life cycle.</p
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