6x6 Matrix Research Articles

Installment of Automation and Modernized Culture Methods Updates a Drug-Sensitivity Screening Platform and Paves the Way to Next-Generation of Precision Medicine

Since the field of drug discovery has seen a rise in the use of primary tumor specimens (PTS) derived from patients with hematological malignancies as live materials in ex vivo drug treatments in late 2010s, they have discovered many intriguing phenotypes of AML cells that can lead to therapeutic insights of this disease category. However, when we consider the fact that current methods in ex vivo drug screenings are not using the most updated culture and cell processing methodology, it is highly expected that modernization of cell processing and analyzing procedures will enable us to detect phenotypes of PTS at a higher resolution. Herein, we have installed our own updated methods in multimodal categories. Even though the number of primary tumor specimens in the screening cohort is not comparable to the ones in other studies using AML PTS, (24 cases of AML, 3 cases of CML, and 1 case of MPN, while we ongoingly recruit more cells), our approach is characterized by its full-automation both in cell processing and data acquisitions using multicolor flow cytometry, as well as updated ex vivo culture methods after optimization using different culture media. We harvested cells for flow cytometry as of day 0, 3, and 6. In a monotherapy section, 24 compounds (6 conventional chemotherapy drugs, 10 epigenetic inhibitors, 4 kinase inhibitors including a FLT3 inhibitor, 3 signal transduction inhibitors, and Venetoclax) were included, while 3 different combination therapies (IDR+ AraC, Ven + 5-Aza, and Ven + AraC) were performed using 6x6 matrix layouts. Drugs were prepared in 384-well plates using a computationally controlled drug dispenser. Using those updated systems, we could discover; 1) Those fully-automated high-throughput platform needs their own optimizations regarding seeding numbers, liquid handling methods, and optimal plastic vessels with low inherent variations of results. 2) PTS are well tolerable to up to 6 days of ex vivo culture 3) Choosing optimal time points for each of the drugs ensures more accurate representation of their drug activities. For example, epigenetic inhibitors have tendency to show better results on day 6 rather than day 3. 4) Multicolor flow cytometry provides previously unseen differences in drug activity profiles upon different clusters, which had not been visible from bulk-grade sensitivity profiling, such as colorimetric viability assay. Those specimens were genetically profiled by whole genome/ exome sequencing, as well as other multi-omics analyses (Bulk RNA seq, methylome analysis, and scRNA seq). 5) Optimizations of ex vivo culture methods not only ensure our better quality of these 6-day drug effects, but also extend the possibility of PTS for further applications by allowing leukemia stem cell fractions to be maintained in vitro for longer periods of time. They include long-term culture and ex vivo expansion of leukemic stem cells using the most updated serum-free liquid culture, and further gene modifications using various vectors. Collectively, our platform for DSS confers next-generation use of primary patient-derived biomaterials so that even a small- to middle-sized group can conduct these complexed assays to test their hypotheses based on primary specimens, which had been possible only in high-volume multi-institutional alliances.

INVESTIGATION OF LASER MARKING AND TEXTURING OF TITANIUM GR 2 WITH FIBER LASER

Titanium Gr 2 is widely used in engineering and medicine due to its excellent mechanical and corrosion-resistant properties. Laser marking is a crucial process for many applications that require high-contrast, durable markings. In this study, we used a Rofin PowerLine F 20 Varia fiber laser to mark titanium Gr 2 with a 6x6 matrix of 5x5 mm squares. We varied the speed (100-1100 mm/s), power (8-18 W), and frequency (100 and 500 kHz) of the laser marking process to investigate their effects on the surface roughness and contrast of the markings. We analyzed the markings using a laser scanning microscope and Adobe Photoshop software. Our results show that the contrast and roughness of the markings were influenced by the frequency, scanning speed, and power. High marking speeds produced lighter markings, while low marking speeds produced darker markings. We also found that the surface roughness increased with higher frequency and powers. Our findings provide valuable insights into the optimal laser marking parameters for titanium Gr 2, which can enhance its performance and durability in various applications.

Abstract 4024: Combining selumetinib with BH3 mimetics enhances activity in MAPK-activated acute myeloid leukemia

Abstract Mitogen-activated protein kinase (MAPK) pathway alterations comprise some of the most frequent mutations in newly diagnosed acute myeloid leukemia (AML). Moreover, MAPK pathway alterations are also emerging as potential mechanisms of resistance to targeted therapy in AML including FLT3 inhibitors and venetoclax. In an ex vivo pharmacologic analysis of primary AML samples, sensitivity to the MEK inhibitor selumetinib (ARRY-142886) was enriched in patient samples resistant to venetoclax. Clinical activity of MAPK pathway inhibitors such as selumetinib has been explored in AML but monotherapy responses were modest. Another MEK inhibitor, cobimetinib, is currently being tested in combination with venetoclax in AML. We sought to understand whether combining selumetinib with BH3 mimetics such as venetoclax would improve efficacy in AML models. We evaluated combination activity of selumetinib plus venetoclax or the MCL1 inhibitor AZD5991 in a panel of AML cell lines. Cells were exposed to a 6x6 matrix of both agents for 72hrs and then viability assessed using CellTiter-Glo. Combination benefit was assessed using highest single agent (HSA) analysis. Selumetinib+AZD5991 demonstrated strong combination benefit (HSA score >0.1, Emax >0.5) in 4/19 AML cell lines. Selumetinib+venetoclax showed strong combination activity in 6/19 lines. Three lines showed benefit with both combinations. Many of these cell lines harbor MAPK pathway mutations including OCI-AML5 (SOS1N233Y, NF1K1385R), ML-2 (KRASA146T), HL-60 (NRASQ61L), and Nomo-1 (KRASG13D). Selumetinib treatment also led to robust BIM induction in vitro. Nomo-1 xenografts were evaluated for in vivo sensitivity to venetoclax (100 mg/kg qd PO), 5-azacytidine (1mg/kg BID q8h 3days on/4days off IP), AZD5991 (30mpk bid q2h qw IV), selumetinib (10 mg/kg bid q8h PO), as well as combinations of venetoclax+5-aza, AZD5991+selumetinib, and venetoclax+selumetinib. Venetoclax and venetoclax+5-aza treatment were ineffective. Selumetinib monotherapy led to 63% tumor growth inhibition (TGI) but tumors eventually grew out through treatment. The combination of selumetinib+venetoclax slightly improved efficacy (81% TGI) but markedly delayed tumor outgrowth (selumetinib monotherapy arm reached mean tumor volume >1000 mm3 on day 17, selumetinib+venetoclax reached average of ~966 mm3 on day 28). Reducing venetoclax dose (30mg/kg qd) or frequency (100mg/kg 3days on/4days off) maintained most of the combination efficacy. Selumetinb+AZD5991 also strongly improved efficacy compared to either monotherapy (88% TGI, mean tumor volume did not exceed ~400mm3 by day 28). Together these data suggest potential for combining MEK inhibitors with BH3 mimetics in AML. Work is ongoing to further understand how scheduling impacts combination efficacy, evaluate the triple combination of selumetinib+BH3 mimetic+azacytidine, and assess efficacy in disseminated models. Citation Format: Courtney L. Andersen, Azadeh Cheraghchi-Bashi, Patricia Jaaks, Elizabeth A. Coker, Kathleen Burke, Justin Cidado, Paul Smith, Corinne Reimer, Raoul Tibes, Mathew Garnett, Jerome Mettetal. Combining selumetinib with BH3 mimetics enhances activity in MAPK-activated acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4024.

Aplikasi Pengolahan Citra Mri Untuk Deteksi Area Kanker Otak Dengan Menggunakan Metode Robinson

Brain cancer can originate from neural elements in brain tissue that are not normal, this brain cancer is primary or is a metastasis. Disorders caused by brain cancer can damage the central nerves in the brain and result in cognitive nervous system damage. Based on data compiled by the International Agency for Research on Cancer, more than 126,000 people worldwide suffer from brain cancer each year and more than 97,000 die. Several things are related because it is difficult to see visually because in general the boundaries are not clear what else if it is still at an early stage, the contrast is not clear and sometimes even resembles normal tissue. The problem faced by experts is that it is difficult to distinguish brain cancer from normal tissue if the age of brain cancer is still in its early stages because the contrast is still not clear. The Robinson method was introduced by Robinson in 1997. This operator is identical to a 6x6 matrix with H1 to H8, because a 3 level Robinson operator convolution table calculates the direction and presence of an edge is done in 2 steps, the main step of the calculation method is the same as the Kirsch calculation, the difference is only on the mask (kernel) value

Abstract P255: Alvocidib synergizes with BRD4 inhibitors to improve cytotoxity in an AML cell line

Abstract The super enhancer complex (SEC) is a group of transcription regulatory proteins that coordinate the expression of genetic programs which determine cell identity and drive diseases such as cancer. In acute myeloid leukemia (AML), SECs have been shown to turn on transcriptional programs that drive tumorigenesis and progression. SEC-regulated transcription begins as Cyclin-Dependent Kinase 9 (CDK9) and Cyclin T1 are recruited from an inhibitory complex by bromodomain 4 (BRD4) and brought to the transcriptional start site of genes. CDK9 phosphorylates RNA polymerase II, releasing it from the SEC and leading to transcriptional elongation and gene expression. Alvocidib is a potent CDK9 inhibitor with clinical activity in AML from multiple Phase II studies. Additionally, BRD4 inhibitors have shown early promise in clinical studies with a focus on AML. Starting with the observation of close association of CDK9 and BRD4 and the central role of the SEC in AML, we previously showed that CDK9 inhibitors combined with bromodomain inhibitors inhibited the SEC more effectively than either of these compounds alone. In this study, we sought to quantify the synergy between alvocidib and each of the BRD4 inhibitors, OTX015, IBET762, and CPI-0610, in the MV-4-11 AML cell line. After determining the single agent IC50 value of each agent, 6x6 matrix combination assays were used to determine synergy between alvocidib and OTX015, IBET762, or CPI-0610. The matrix combination assays consisted of concentrations of each : 4x IC50, 2x IC50, 1x IC50, 0.5x IC50, 0.25x IC50, and 0.125x IC50 value. In the combination assays, the cells were incubated with alvocidib for 48 h, then a BRD4 inhibitor was added, and the cells were incubated with alvocidib and the BRD4 inhibitor for a further 48 h. Combination index (CI) values were calculated using the Chou-Talalay method, where CI values less than 1 indicate synergism and lower CI values indicating stronger synergism. Synergistic interactions were observed in MV-4-11 cells for all three combinations of alvocidib plus a BRD4 inhibitor. For the combination of alvocidib and OTX015, synergy was observed for 81% (29/36) of the tested combinations, with the strongest synergy (CI = 0.155) observed at 20 nM alvocidib and 1.472 µM OTX015. For the combination of alvocidib and IBET762, synergy was observed for 75% (27/36) of the tested combinations, with the strongest synergy (CI = 0.144) observed at 10 nM alvocidib and 6.288 µM IBET762. For the combination of alvocidib and CPI-0610, synergy was observed for 72% (26/36) of the tested combinations, with the strongest synergy (CI = 0.101) observed at 10 nM alvocidib and 5.312 µM CPI-0610. These results suggest that combination strategies might be rationally designed to improve tumor targeting effects while reducing adverse side effects. Clinical studies utilizing these combination strategies are the next steps to further explore this approach. Citation Format: Sal Sommakia, Ethika Tyagi, Yuta Matsumura, Jason M. Foulks, Steven L. Warner. Alvocidib synergizes with BRD4 inhibitors to improve cytotoxity in an AML cell line [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P255.

Abstract 1341: Inhibiting the nuclear exporter XPO1 and the antiapoptotic factor BCL2 is synergistic in XPO1 and SF3B1 mutant hematologic malignancies

Abstract Mutations in the nuclear exporter XPO1 and the spliceosomal protein SF3B1 are bona fide cancer drivers and occur across a spectrum of hematologic cancers, specifically in chronic lymphocytic leukemia (CLL), myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Selinexor is a potent, XPO1 inhibitor that was recently approved in diffuse large B-cell lymphoma and is being tested in MDS and AML. The BCL2 inhibitor, venetoclax, is approved for use in CLL and has also shown to be effective in myeloid malignancies. XPO1 inhibition exerts its antineoplastic effects by blocking key tumorigenic pathways, such as NFκB, and decreasing the anti-apoptotic protein MCL1. We therefore hypothesized that combining selinexor and venetoclax would have potential synergy and could be used to target hematologic malignancies bearing XPO1 and SF3B1 mutations. We first determined whether XPO1 and SF3B1 mutant cell lines showed differential response to either selinexor or venetoclax monotherapy. Five lymphoma cell lines; 3 diffuse large B-cell lymphoma (SU-DHL-6, SU-DHL-16, FARAGE) and 2 classical Hodgkin lymphoma (L428 and SUP-HD1), were used based on the presence or absence of XPO1 mutations. SUDHL-16 and SUP-HD1 are heterozygous for the XPO1 E571K hotspot mutation while SUDHL-6, FARAGE and SUP-HD1 are wildtype. These cell lines were used to assess sensitivity to Selinexor or Venetoclax using the CellTiter Glo assay. The XPO1 mutant cells showed increased sensitivity to selinexor (IC50 = 16-35nM vs 41-231nM). Additionally, the XPO1 mutant cell lines showed increased sensitivity to single-agent venetoclax (XPO1 mutant IC50 = 2-13nM vs 5-2853nM). SF3B1 K666N mutant K562 and Nalm-6 cells also showed increased sensitivity to selinexor compared to wildtype cells (IC50 =116-190nM vs 212-1405nM), as well as to venetoclax as compared to wildtype (IC50 =149nM-1.28 μM vs 1.26-1.4μM). Next, we tested the synergy of the combination of these drugs in the XPO1 and SF3B1 mutant cell lines. Increasing concentrations of the individual drugs were applied to each individual cell line in a 6x6 matrix and the Bliss Independence model was used to calculate synergy of the combination. As hypothesized, the combination of Selinexor and venetoclax showed synergy in both the XPO1 and SF3B1 mutant cell lines (synergy scores 4.5-16.5). Western blots of treated wildtype versus mutant cells showed decreased levels of p65 and MCL1 with selinexor (but not venetoclax) that was enhanced with combination therapy, specifically in mutant cell lines. In conclusion, inhibiting the nuclear exporter XPO1 and the anti-apoptotic factor BCL2 is synergistic in both XPO1 and SF3B1 mutant cells. This combination is highly promising as an all oral regimen for hematologic malignancies bearing these mutations. Further, preclinical testing in in vivo using XPO1 and SF3B1 mutant and wildtype mice is ongoing. Citation Format: Tulasigeri M. Totiger, Sana Chaudhry, Jumana Afaghani, Justin Taylor. Inhibiting the nuclear exporter XPO1 and the antiapoptotic factor BCL2 is synergistic in XPO1 and SF3B1 mutant hematologic malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1341.

Inhibiting the Nuclear Exporter XPO1 and the Antiapoptotic Factor BCL2 Is Synergistic in XPO1 Mutant and Wildtype Lymphoma

We have recently shown that XPO1 mutations are drivers of lymphomagenesis and occur across B-cell lymphomas, specifically in chronic lymphocytic leukemia (CLL), classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma. The co-occurrence of other oncogenic events cooperating with XPO1 provides an opportunity for combined targeted therapy. Increased expression of the anti-apoptotic factor BCL2 has long been known to be a critical part of the pathophysiology of B-cell lymphomas. Recently, the oral BCL2 inhibitor, venetoclax, was approved in CLL and is currently being evaluated in clinical trials for other B-cell lymphomas. Selinexor is a potent, oral XPO1 inhibitor that was recently approved in multiple myeloma and diffuse large B-cell lymphoma. XPO1 inhibition exerts its antineoplastic effects by blocking key lymphomagenic pathways, such as NFκB, and decreasing the anti-apoptotic protein survivin. We therefore hypothesized that combining selinexor and venetoclax would have potential synergy and provide an oral precision combination therapy for relapsed, refractory lymphoma. We first set out to determine whether XPO1 mutant lymphoma cell lines showed differential response to either selinexor or venetoclax monotherapy. Five lymphoma cell lines; 3 diffuse large B-cell lymphoma (SU-DHL-6, SU-DHL-16, FARAGE) and 2 classical Hodgkin lymphoma (L428 and SUP-HD1), were subjected to next-generation sequencing (NGS) to assess for the presence or absence of XPO1 mutations. SUDHL-16 and SUP-HD1 were heterozygous for the XPO1 E571K hotspot mutation while SUDHL-6, FARAGE and SUP-HD1 were wildtype at the XPO1 locus. These 5 cell lines were used to assess sensitivity to Selinexor and/or Venetoclax. The CellTiter Glo assay was used to assess cell viability after 72 hours of treatment. Assays were performed in triplicate on 96-well plates that were read using a Spectramax plate reader. The XPO1 mutant cells showed increased sensitivity to selinexor (XPO1 mutant IC50 = 16-35nM; XPO1 WT IC50 = 41-231nM) as previously seen in conditional knockin mouse models of XPO1 mutant CLL (Figure A). Additionally, the XPO1 mutant cell lines showed increased sensitivity to single-agent venetoclax (XPO1 mutant IC50 = 2-13nM; XPO1 WT IC50 = 5-2853nM), an observation that has not previously been made (Figure B). Next, we tested the synergy of the combination of selinexor and venetoclax in the XPO1 mutant and wildtype cell lines. Increasing concentrations of the individual drugs were applied to each individual cell line in a 6x6 matrix. The cell viability percentage for each concentration was then entered into a synergy finder (www. synergyfinder.fimm.fi). The Bliss Independence model was used to calculate synergy of the Selinexor-Venetoclax combinations. As hypothesized, the combination of selinexor and venetoclax indeed showed synergy in both the wildtype and mutant XPO1 cell lines. Furthermore, the XPO1 mutant cell lines showed a higher degree of synergy compared to the wildtype cells (Figure C). Finally, a remarkable patient allowed us to test this combination ex vivo. This patient with CLL had undergone multiple therapies including chemoimmunotherapy, ibrutinib and venetoclax monotherapies. This patient had a founder XPO1 E571K mutation and also had acquired a BTK C481S ibrutinib resistance mutation and MYC amplification. These cells were unique in that they were easily able to be tested in ex-vivo culture to test sensitivity to different therapies. When tested with chemotherapy or ibrutinib they were completely resistant, and even with venetoclax they were fairly resistant; however, they remained sensitive to XPO1 inhibition with Selinexor. Selinexor and venetoclax showed remarkable synergy measured by a BLISS delta score of 18.78 (Figure D). In conclusion, inhibiting the nuclear exporter XPO1 and the anti-apoptotic factor BCL2 is synergistic in both XPO1 wildtype and mutant lymphoma. XPO1 mutant lymphomas show increased sensitivity to both selinexor and venetoclax. Additionally, selinexor and venetoclax showed a higher degree of synergism in XPO1 mutant lymphoma cell lines and were highly synergistic in primary XPO1 mutant CLL patient cells ex vivo. This combination is highly promising as an all oral alternative for relapsed, refractory lymphoma. Next steps include preclinical testing in mouse models in vivo using XPO1 mutant and wildtype mice crossed with mice overexpressing BCL2. Figure Disclosures No relevant conflicts of interest to declare.

Neural network for mechanical property estimation of multilayered laminate composite

Composites are made of combining two or more materials wherein the favorable properties of each material is contributed to improve the overall properties of the final material. In a multi-layered composite, layers of different laminates are stacked on top of each other in different alignments, such that it can meet the overall functional needs of the material such as desired bending, stretching, shearing, etc. with applied forces/moments. The layers are stacked on top of each other depending on the strength or thickness requirement. The mechanical properties of the composite or organized stack of layers are defined by the ABD matrix. The ABD matrix is a 6x6 matrix that links the applied loads and the associated strains in the laminate. 'A' represents the extensional stiffness which relates in-plane forces with mid-plane strains. 'B' represents the coupling stiffness which relates in-plane forces with mid-plane curvatures. 'D' represents bending stiffness which relates resultant moments with mid-plane curvatures. In this work, a neural network is constructed to predict the eigen values of the ABD matrix as a function of the number of layers and angles of orientation. The purpose of this model is to demonstrate the applicability of neural networks for modeling the mechanical properties of composites from the stacking pattern of the laminates.

Modifikasi Enkripsi Dan Dekripsi AES Menggunakan Polybius Chiper Dalam Pengamanan Data

Data is a file that can be confidential so it requires a data security process to maintain confidentiality. Kripotgrrafi is a data security process that can be used based on the use of algorithms, one of which is AES. AES is a modern algorithm that can be modified to improve confusion and diffusion in cryptography. AES combination can be done using Polybius which has cryptographic diffusion properties. This study modified the AES using 6x6 and 10x10 polybius matrices that were performed on plaintext and plaintext and keys. Analysis was carried out based on the highest bit change rate found in modification II in the plaintext and 6x6 matrix keys, which amounted to 51.8% using the avalanche effect test. The results of the AE compared to the expected results using chi square with the modified AES results can increase the AE by 5% with the real level is 0,05 and the degree of freedom is 4 . Execution time was tested in this study with the results of the AES modification time longer than the standard AES because the complexity of the algorithm affects both encryption and decryption time. Abstract Data is a file that can be confidential so it requires a data security process to maintain confidentiality. Kripotgrrafi is a data security process that can be used based on the use of algorithms, one of which is AES. AES is a modern algorithm that can be modified to improve confusion and diffusion in cryptography. AES combination can be done using Polybius which has cryptographic diffusion properties. This study modified the AES using 6x6 and 10x10 polybius matrices that were performed on plaintext and plaintext and keys. Analysis was carried out based on the highest bit change rate found in modification II in the plaintext and 6x6 matrix keys, which amounted to 51.8% using the avalanche effect test. The results of the AE compared to the expected results using chi square with the modified AES results can increase the AE by 5% with the real level is 0,05 and the degree of freedom is 4 . Execution time was tested in this study with the results of the AES modification time longer than the standard AES because the complexity of the algorithm affects both encryption and decryption time.

Modifikasi enkripsi dan dekripsi AES menggunakan polybius chiper dalam pengamanan data

Data is a file that can be confidential so it requires a data security process to maintain confidentiality. Kripotgrrafi is a data security process that can be used based on the use of algorithms, one of which is AES. AES is a modern algorithm that can be modified to improve confusion and diffusion in cryptography. AES combination can be done using Polybius which has cryptographic diffusion properties. This study modified the AES using 6x6 and 10x10 polybius matrices that were performed on plaintext and plaintext and keys. Analysis was carried out based on the highest bit change rate found in modification II in the plaintext and 6x6 matrix keys, which amounted to 51.8% using the avalanche effect test. The results of the AE compared to the expected results using chi square with the modified AES results can increase the AE by 5% with the real level is 0,05 and the degree of freedom is 4 . Execution time was tested in this study with the results of the AES modification time longer than the standard AES because the complexity of the algorithm affects both encryption and decryption time.Abstract Data is a file that can be confidential so it requires a data security process to maintain confidentiality. Kripotgrrafi is a data security process that can be used based on the use of algorithms, one of which is AES. AES is a modern algorithm that can be modified to improve confusion and diffusion in cryptography. AES combination can be done using Polybius which has cryptographic diffusion properties. This study modified the AES using 6x6 and 10x10 polybius matrices that were performed on plaintext and plaintext and keys. Analysis was carried out based on the highest bit change rate found in modification II in the plaintext and 6x6 matrix keys, which amounted to 51.8% using the avalanche effect test. The results of the AE compared to the expected results using chi square with the modified AES results can increase the AE by 5% with the real level is 0,05 and the degree of freedom is 4 . Execution time was tested in this study with the results of the AES modification time longer than the standard AES because the complexity of the algorithm affects both encryption and decryption time.

P300 Tabanlı Beyin Bilgisayar Arayüzü Sistemlerinde Uyaranlar Arası Sürenin ve Uyaran Yapısının Performansa Etkisi

Elektroensefalografi temelli beyin bilgisayar arayüzü sistemleri kas sistemini kullanamayan hastalar için dış dünya ile iletişimini mümkün kılmaktadır. EEG temelli beyin bilgisayar arayüzü sistemleri için çeşitli beyin sinyal aktiviteleri kullanılmaktadır. Olay odaklı potansiyellerden bir tanesi olan P300 sinyali beyin bilgisayar arayüzü sistemleri için elverişli bir beyin sinyalidir. P300 tabanlı bir beyin bilgsayar arayüzü için en önemli performans parametrelerinden birisi sınıflandırma doğruluk oranıdır. Bu çalışmada satır sütun temelli P300 heceletici yapısındaki değişiklikle daha yüksek doğruluk oranı ile elde edilmesi hedeflenmiştir. P300 heceleticisi matris yapısında ve uyaranların aralık süreleri üzerinde değişiklikler yapılmıştır. Bundan önceki bir çok çalışma P300 heceletici yapısındaki uyaran renk ve biçimlerindeki değişiklikler ile yapılmıştır. Uyaran yapısı ve uyaran aralık sürelerindeki değişikleri kıyaslayıcı P300 heceleticileri ile ilgili çalışmalar yeterli seviyede değildir. Bu çalışmada dört farklı yapıdaki satır sütun bazlı P300 heceletici kullanılarak deneyler yapılmıştır. Deneyler ile toplanan EEG kayıtları ön işlemden geçirildikten sonra adımsal doğrusal ayrışım analizi ile sınıflandırılmıştır. Sınıflandırma neticesinde bu çalışmada karşılaştırılan heceleticilerden; 4x4 satır sütın bazlı P300 heceleticinin 150 ms uyaran aralık süresine sahip olan yapıdaki formu, ortalama doğruluk oranı %84,76 ile en yüksek olarak tespit edilmiştir. En düşük performans ise; 6x6 satır sütın bazlı P300 heceleticinin 300 ms uyaranlar arası geçiş süresine sahip modunda %50,48 olarak gözlenmiştir. Bu çalışma, satır sütun bazlı P300 heceleticisinin uyaran matris yapısındaki değişikliği ve farklı uyaran aralık sürelerinde yapılan deneylerle yüksek doğruluk oranı ile elde edilebileceğini göstermiştir.

Applying Auto Regression Techniques on Amyotrophic Lateral Sclerosis Patients EEG Dataset with P300 Speller

This paper deals with the application of auto regression techniques to find the best fitting curves for the Electroencephalograph (EEG) data of Amyotrophic Lateral Sclerosis (ALS) patients with P300 speller. ALS is a degenerative neuron disease bringing gradual impairment of motor neurons leading to total loss of voluntary limb movement in sometime. A P300 speller is a 6X6 matrix of English alphabets in which each column and each row is highlighted periodically and the patient has to concentrate on the correct alphabet to evoke P300 event related potential. Auto regression is a curve fitting technique for sampled data. The best fit obtained in this study for the ALS patients’ EEG channels which can used to predict incomplete or subsequent EEG data to enhance communication through P300 speller.

BV analysis of tachyon fluctuation around multi-brane solutions in cubic string field theory

We study whether the tachyon mode exists as a physical fluctuation on the 2-brane solution and on the tachyon vacuum solution in cubic open string field theory. Our analysis is based on the Batalin-Vilkovisky formalism. We first construct a set of six string states which corresponds to the set of fields and anti-fields containing the tachyon field. Whether the tachyon field can exist as a physical fluctuation is determined by the 6x6 matrix defining the anti-bracket in the present sector. If the matrix is degenerate/non-degenerate, the tachyon field is physical/unphysical. Calculations for the pure-gauge type solutions in the framework of the KBc algebra and using the Ke-regularization lead to the expected results. Namely, the matrix for the anti-bracket is degenerate/non-degenerate in the case of the 2-brane/tachyon-vacuum solution. Our analysis is not complete, in particular, in that we have not identified the four-fold degeneracy of tachyon fluctuation on the 2-brane solution, and moreover that the present six states do not satisfy the hermiticity condition.

Neutrino Oscillations with Three Active and Three Sterile Neutrinos

This is an extension of estimates of the probability of $\nu$ to $e$ neutrino oscillation with one sterile neutrino to three sterile neutrinos, using a 6x6 matrix. Since the mixing angle for only one sterile neutrino has been experimentally determined, we estimate the $\nu$ to $e$ neutrino oscillation probability with different mixing angles for two of the sterile neutrinos.

Assisted Research of the Robots Kinematics and Dynamics Behavior with LabVIEW Instrumentation

In the industrial robots research one of the most important problem is to know cinematic and dynamic behavior to use them in the optimization process of the 3D space trajectory. Now, in the world, the results of the dynamic behavior research where obtained by research without one complex matrix model and without LabVIEW virtual instrumentation. In this paper it is show one assisted method and mathematical modeling with quadratic 6x6 matrix equations in the theoretical and experimental cinematic and dynamic analyze of didactical robot. For that where realized and used many virtual LabVIEW instruments (VI) and one didactical robot. All VI-s work on-line with the possibility to change some constructive and functional parameters of the structure or of the command low and see what is happened with the position, velocities, accelerations, forces and moments in all robot’s joints It is possible to try different control low of the movements like: simultaneously, successive or successive and simultaneously in all joints. The most important of the results is the possibility to know in every moment what is the better velocity characteristic for the dynamic behavior, validate easily the dynamic model and to know what is the variation of the absolute joint’s moments, forces, accelerations and velocities to can calculate all mechanical parts in each joints.

An Image Smearing Technique to Improve Pigeon Hole Imaging (PHI)

This new imaging modality arises as an extension of the 6-electrode Focused Impedance Method (FIM) developed in our laboratory earlier. Current is driven through two concentric pairs of orthogonally placed electrodes while several potential electrodes are located along a diagonal centrally. Through a combination of current drives and potential measurements across adjacent diagonal electrodes, it is possible to obtain admittance sums along the rows and columns of a square matrix formed by these diagonally placed potential electrodes. Through simple backprojection along the rows and columns it is possible to reconstruct a crude image in a square matrix form. Due to its resemblance, the name Pigeon Hole Imaging (PHI) has been coined. The concept has been experimentally tested to identify the location of a single target object in a background of uniform conductivity in 2D and 3D phantoms, in 2x2 and 6x6 matrix formations respectively. Taking the highest pixel to represent the object position the images were correct in all the pixels of the 2x2 image but in only 16 of the 36 pixels adjacent to the diagonal electrodes in the 6x6 image. However, a systematic pattern of image shift was observed in most of the other pixels in the latter, based on which a set of rules were made to correct the image in another 14 pixels. Thus excepting the furthest 6 pixels, correct image could be obtained in all 30 pixels. Thus PHI will be useful in locating exact positions of single target objects simply. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14673 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 11-20

Modified Block Playfair Cipher using Random Shift Key Generation

In this paper conventional Playfair Cipher is being modified by encrypting the plaintext in blocks. For each block the keyword would be the same but the matrix will shift by some random value. As a result of which the diagram analysis would be very difficult which is done in the traditional Playfair Cipher to obtain the plaintext from the ciphertext. The shift value will be generated using SHA-1 which is very secure. Playfair Cipher method, based on polyalphabetic cipher is relatively easy to break because it still leaves much of the structure and a few hundred of letters of ciphertext are sufficient. To add to its security and to make it more usable we are using 6x6 matrix instead of 5x5 which will be able to cover 26 alphabets in English and ten numerals i.e. from 0 to 9. This 6x6 matrix eliminate the case of putting of 2 alphabets (I and J) together in the matrix as it was in the 5x5 matrix. Plaintext as well as key can be numeral, alphabetic or combination of both.

Extension of Playfair Cipher using 16X16 Matrix

The role of Cryptography in today‟s digital world is significant. It secures information mathematically by mangling message with key. The privacy of intended sender and receiver information is protected from eavesdropper. The objective of the paper is playfair cipher. The existing methods of playfair cipher are studied. The restrictions of earlier works a playfair cipher using 5X5 matrix, 7X4 matrix and 6X6 matrix are overcome in the proposed work. The proposed method plays a 16X16 matrix giving strength to playfair cipher. The proposed work is an enhancement to the existing algorithms that uses 16X16 matrix to pick cipher characters. It makes use of alphabets both lower and uppercase characters, number and special characters for constructing the contents of the matrix. General Terms Encryption, Decryption, Plaintext, Ciphertext.