A DISTRIBUTED APPROACH TO ANT COLONY OPTIMIZATION

Swarm Intelligence(SI) is the emergent collective intelligence of groups of simple agents. Economy is an example of SI. Simulating an economy using Ant Colony algorithms would allow prediction and control of fluctuations in the complex emergent behavior of the simulated system. Such a simulation is far beyond SI's capabilities, which is still in its infancy. This paper presents a distributed approach implementing Ant Colony Optimization(ACO). We present our agent based architecture of ACO and initial experimental results on the Travelling Salesman Problem. The innovation of our work consists of: i)representing network nodes as software agents, ii) representing software agents as software objects that are passed as messages between the nodes according to ACO rules.Swarm Intelligence, Ant Colony Optimization, Multi-Agent, Distributed, Heuristis

Pengaruh Bahan Pelat Penyerap Dan Geometri Kaca Penutup Terhadap Kinerja Solar Still di Kota Ngabang, Kalimantan Barat

Keterbatasan air bersih pada musim kemarau menjadi permasalahan yang dihadapi oleh pendudukan di sekitar Kota Ngabang. Dengan terbatasnya ketersediaan air bersih, maka sebagian masyarakat setempat menggunakan air sumur bor untuk memenuhi kebutuhan air bersih sehari-hari. Kendala yang dihadapi dalam penggunaan air sumur bor adalah adanya zat logam berbahaya yang terkandung di dalam air sumur bor. Dalam proses pemisahannya, distilasi dengan menggunakan tenaga surya merupakan alternatif yang tepat untuk menghasilkan air bersih. Penelitian ini bertujuan untuk meningkatkan kinerja solar still dengan memvariasikan bahan pelat penyerap dan geometri kaca penutup. Variasi bahan pelat penyerap yang digunakan adalah cat hitam dan batu kerikil. Sedangkan variasi geometri kaca penutup yaitu berbentuk satu sisi, dua sisi simetri, dan piramida. Dimensi solar still pada penelitian ini 0,91 m2. Waktu pengambilan data dilakukan selama 13 jam dengan rentang waktu 10 menit. Hasil penelitian ini menunjukan bahwa penggunaan batu kerikil sebagai pelat penyerap dan geometri kaca penutup berbentuk piramida dapat meningkatkan kinerja solar still. Produktivitas air distilasi tertinggi selama penelitian yaitu 13 jam dengan total radiasi matahari sebesar 21778,32 kj/m2.hari yang dilakukan pada tanggal 31 maret 2019 terdapat pada pelat penyerap yang dilapisi batu kerikil sebanyak 3,64 liter , dan memiliki efisiensi solar still sebesar 43,93%. Sedangkan pelat penyerap dilapisi cat hitam memiliki produktivitas air distilasi sebanyak 2,42 Liter dan memiliki efisiensi sebesar 29,32%. Sedangkan pada variasi kaca penutup, produktivitas air distilasi tertinggi selama penelitian dengan total radiasi matahari sebesar 25705,08 kj/m2.hari yang dilakukan pada tanggal 10 april 2019 terdapat pada kaca penutup berbentuk piramida dengan produksi air distilasi sebanyak 4,75 Liter dan memiliki efisiensi solar still sebesar 48,26%. Sedangkan kaca penutup dua sisi memiliki produksi air distilasi sebanyak 4,50 Liter dan memiliki efisiensi solar still sebesar 45,81%. Kaca penutup satu sisi mampu memproduksi air distilasi sebanyak 4,35 Liter dan memiliki efisiensi solar still sebesar 44,46%

Analisis Keunikan Fitur Cwt Sinyal Eeg Untuk Pembuatan Lima Indikator Pengendalian Kursi Roda BCI

Penelitian ini dilakukan dengan tujuan untuk membuat lima indikator pengendalian kursi roda BCI berdasarkan fitur yang diekstraksi dari sinyal elektroensefalogram (EEG). Sinyal EEG didekomposisi menggunakan metode continuous wavelet transform (CWT). Nilai rata-rata absolut dan standar deviasi dari sinyal yang telah didekomposisi tersebut digunakan sebagai fitur. Fitur hasil ekstraksi kemudian dianalisis keunikannya menggunakan metode Friedman. Untuk mendekati sifat alami fitur sinyal EEG yang nonlinier, metode support vector machine (SVM) dengan kernel radial basis function (RBF) digunakan untuk membuat indikator pengendalian kursi roda BCI berdasarkan fitur sinyal EEG yang paling unik. Hasil penelitian ini menunjukkan bahwa metode yang diusulkan dapat mengukur tingkat keunikan fitur CWT sinyal EEG. Dari penelitian penentuan keunikan fitur CWT dapat diperoleh lima indikator pengendalian untuk kursi roda BCI yang didasarkan pada sinyal EEG dari Neurosky MW001. Akan tetapi, akurasi kelima indikator tersebut belum dapat digunakan sebagai indikator kontrol untuk aktuator kursi roda BCI. Hal ini disebabkan oleh tingkat kepercayaan rata-rata indikator tersebut masih di bawah 60%, sedangkan untuk indikator yang berpasangan masih di bawah 70%

Identifikasi Pola Sebaran Air Panas Menggunakan Metode Resistivitas Dan Georadar Di Daerah Gunung Pandan Jawa Timur

Telah dilakukan penelitian menggunakan metode resistivitas dan georadar di daerah gunung Pandan, Jawa Timur, Indonesia, untuk mengidentifikasi struktur bawah permukaan berdasarkan interpretasi 3D dan menentukan pola sebaran air panas. Akusisi data resistivitas dilakukan pada 16 titik VES (Vertical Electrical Sounding) dengan desain penelitian berbentuk grid melingkupi manifestasi mataair panas, sedangkan akuisisi data georadar dilakukan scanning pada 4 zona manifestasi mataair panas yang berada dalam area akuisisi data resistivitas. Hasil interpretasi 3D struktur bawah permukaan berdasarkan data resistivitas di daerah gunung Pandan menunjukan rentang nilai dari 1,06-20064,09 Ωm, berada pada kedalaman 0,58-147 m. Terdapat 4 lapisan batuan yaitu: a. Lapisan batuan dengan nilai resistivitas <20 Ωm diinterpretasikan sebagai lapisan yang mengandung air panas diduga merupakan batuan lempung pasiran (clay sand). Lapisan yang mengandung air panas panas berada dekat permukaan hingga kedalaman 114 m. b. Lapisan batuan dengan nilai resistivitas antara 20,01-50,00 Ωm diinterpretasikan sebagai lapisan kedap air diduga merupakan batuan tuff. c. Lapisan batuan dengan nilai resistivitas antara 50,01-100 Ωm diinterpretasikan sebagai lapisan penyimpan air (akuifer) diduga merupakan batu pasir (sandstone). d. Lapisan batuan dengan nilai resistivitas >100,01 Ωm diinterpretasikan sebagai lapisan sumber panas (source) diduga merupakan breksi gunungapi. Hasil interpretasi 3D struktur bawah permukaan berdasarkan hasil perekaman GPR menunjukan adanya lapisan rongga (cavity) diduga sebagai lapisan yang mengandung air panas tersebar pada semua line profil berada dekat permukaan hingga kedalaman 0,07-16,88 m. Pola sebaran air panas berdasarkan data resistivitas dan georadar di daerah gunung Pandan bersifat mengelompok dan menyebar. Pola sebarannya berasal dari barat daya-timur lau

Is nebulized saline a placebo in COPD?

BACKGROUND: Many trials of nebulized therapy have used nebulized saline as a "placebo". However, nebulized isotonic saline is sometimes used to assist sputum expectoration and relieve breathlessness in COPD patients. We designed this study to establish if nebulized saline had a placebo effect or a clinical effect. METHODS: 40 patients were studied following hospital admission for exacerbated COPD (mean FEV1 30% predicted). Patients were randomised to single-blind administration of either 4 mls of nebulized isotonic saline using an efficient nebulizer (active group n = 20) or an inefficient nebulizer (placebo group n = 20). Spirometry and subjective breathlessness scores (Modified Likert Scale) were measured before nebulized treatment and 10 minutes after treatment. RESULTS: There was no significant change in FEV1 after active or placebo nebulized saline treatment. Patients reported a 4% improvement in mean breathlessness score following placebo (Wilcoxon test; p = 0.37) compared with 23% improvement following active nebulized saline (p = 0.0001). 65% of patients given active nebulized saline but only 5% of the placebo group reported that mucus expectoration was easier after the treatment. CONCLUSIONS: This study lends support to the current use of nebulized saline to relieve breathlessness (possibly by facilitating sputum clearance) in COPD patients. Lung function was not affected. Nebulized saline can therefore be used as a placebo in bronchodilator studies involving COPD patients but it cannot be used as a placebo in trials assessing symptom relief

Investigation of the role of SDHB inactivation in sporadic phaeochromocytoma and neuroblastoma

Germline mutations in the succinate dehydrogenase (SDH) (mitochondrial respiratory chain complex II) subunit B gene, SDHB, cause susceptibility to head and neck paraganglioma and phaeochromocytoma. Previously, we did not identify somatic SDHB mutations in sporadic phaeochromocytoma, but SDHB maps to 1p36, a region of frequent loss of heterozygosity (LOH) in neuroblastoma as well. Hence, to evaluate SDHB as a candidate neuroblastoma tumour suppressor gene (TSG) we performed mutation analysis in 46 primary neuroblastomas by direct sequencing, but did not identify germline or somatic SDHB mutations. As TSGs such as RASSF1A are frequently inactivated by promoter region hypermethylation, we designed a methylation-sensitive PCR-based assay to detect SDHB promoter region methylation. In 21% of primary neuroblastomas and 32% of phaeochromocytomas (32%) methylated (and unmethylated) alleles were detected. Although promoter region methylation was also detected in two neuroblastoma cell lines, this was not associated with silencing of SDHB expression, and treatment with a demethylating agent (5-azacytidine) did not increase SDH activity. These findings suggest that although germline SDHB mutations are an important cause of phaeochromocytoma susceptibility, somatic inactivation of SDHB does not have a major role in sporadic neural crest tumours and SDHB is not the target of 1p36 allele loss in neuroblastoma and phaeochromocytoma

Incidence, Risk Factors, and Impact of Severe Neutropenia After Hyperthermic Intraperitoneal Mitomycin C

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are considered the standard of care for patients with peritoneal dissemination of appendiceal cancer and are increasingly being evaluated for use in patients with carcinomatosis from colon cancer. Mitomycin C (MMC) is one of the most frequently used HIPEC agents in the management of peritoneal-based gastrointestinal malignancies. This study analyzes the incidence and risk factors for developing neutropenia following MMC-HIPEC combined with CRS. All patients undergoing CRS and MMC-HIPEC for appendiceal cancer between January 1993 and October 2006 were retrospectively reviewed. Logistic regression was used to identify risk factors for the development of neutropenia, defined as an absolute neutrophil count (ANC) &lt;1,000/mm3. One hundred and twenty MMC-HIPEC were performed in 117 patients with appendiceal cancer. The incidence of neutropenia was 39%. Neutropenia occurred in 57.6% of female and 21.3% of male patients (p &lt; 0.0001). Female gender and MMC dose per body surface area (BSA) were independent risk factors for neutropenia on multivariable logistic regression [odds ratio (OR) of neutropenia in females = 3.58 (95% confidence interval, CI: 1.52, 8.43); OR for 5 unit (mg/m2) increase in MMC dose per BSA = 3.37 (95% CI: 1.72, 6.63)]. Neutropenia did not increase the risk of mortality, postoperative infection or length of hospital stay. Neutropenia is a frequent complication associated with MMC-HIPEC. Female sex and MMC dose per BSA are independent risk factors for neutropenia. These differences must be considered in the management of patients undergoing MMC-HIPEC to minimize the toxicity of the procedure

Cognitive function, social integration and mortality in a U.S. national cohort study of older adults

<p>Abstract</p> <p>Background</p> <p>Prior research suggests an interaction between social networks and Alzheimer's disease pathology and cognitive function, all predictors of survival in the elderly. We test the hypotheses that both social integration and cognitive function are independently associated with subsequent mortality and there is an interaction between social integration and cognitive function as related to mortality in a national cohort of older persons.</p> <p>Methods</p> <p>Data were analyzed from a longitudinal follow-up study of 5,908 American men and women aged 60 years and over examined in 1988–1994 followed an average 8.5 yr. Measurements at baseline included self-reported social integration, socio-demographics, health, body mass index, C-reactive protein and a short index of cognitive function (SICF).</p> <p>Results</p> <p>Death during follow-up occurred in 2,431. In bivariate analyses indicators of greater social integration were associated with higher cognitive function. Among persons with SICF score of 17, 22% died compared to 54% of those with SICF score of 0–11 (p < 0.0001). After adjusting for confounding by baseline socio-demographics and health status, the hazards ratio (HR) (95% confidence limits) for low SICF score was 1.43 (1.13–1.80, p < 0.001). After controlling for health behaviors, blood pressure and body mass, C-reactive protein and social integration, the HR was 1.36 (1.06–1.76, p = 0.02). Further low compared to high social integration was also independently associated with increased risk of mortality: HR 1.24 (1.02–1.52, p = 0.02).</p> <p>Conclusion</p> <p>In a cohort of older Americans, analyses demonstrated a higher risk of death independent of confounders among those with low cognitive function and low social integration with no significant interaction between them.</p

Somatic VHL gene alterations in MEN2-associated medullary thyroid carcinoma

BACKGROUND: Germline mutations in RET are responsible for multiple endocrine neoplasia type 2 (MEN2), an autosomal dominantly inherited cancer syndrome that is characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, and parathyroid hyperplasia/adenoma. Recent studies suggest a "second hit" mechanism resulting in amplification of mutant RET. Somatic VHL gene alterations are implicated in the pathogenesis of MEN2 pheochromocytomas. We hypothesized that somatic VHL gene alterations are also important in the pathogenesis of MEN2-associated MTC. METHODS: We analyzed 6 MTCs and 1 C-cell hyperplasia (CCH) specimen from 7 patients with MEN2A and RET germline mutations in codons 609, 618, 620, or 634, using microdissection, microsatellite analysis, phosphorimage densitometry, and VHL mutation analysis. RESULTS: First, we searched for allelic imbalance between mutant and wild-type RET by using the polymorphic markers D10S677, D10S1239, and RET on thyroid tissue from these patients. Evidence for RET amplification by this technique could be demonstrated in 3 of 6 MTCs. We then performed LOH analysis using D3S1038 and D3S1110 which map to the VHL gene locus at 3p25/26. VHL gene deletion was present in 3 MTCs. These 3 MTCs also had an allelic imbalance between mutant and wild-type RET. Mutation analysis of the VHL gene showed a somatic frameshift mutation in 1 MTC that also demonstrated LOH at 3p25/26. In the 2 other MTCs with allelic imbalance of RET and somatic VHL gene deletion, no somatic VHL mutation could be detected. The CCH specimen did neither reveal RET imbalance nor somatic VHL gene alterations. CONCLUSION: These data suggest that a RET germline mutation is necessary for development of CCH, that allelic imbalance between mutant and wild-type RET may set off tumorigenesis, and that somatic VHL gene alterations may not play a major role in tumorigenesis of MEN2A-associated MTC