651 research outputs found

    Meta-analysis of the efficacy of a single stage laparoscopic management versus two-stage endoscopic management of symptomatic gallstones with common bile duct stones.

    Get PDF
    Background. The optimal treatment of gallstones with associated common bile duct stones in the laparoscopic era is controversial. Various reviews and decision based algorithms have been published, but the superior treatment modality is unclear. Therefore, a metaanalysis was conducted to compare the two most commonly used treatment strategies. Methods. A systematic review was conducted to compare single stage laparoscopic cholecystectomy with common bile duct exploration versus a combined endoscopic and laparoscopic treatment. Eligible studies were identified using a search of Medline, Embase, Cochrane and Science Citation Index Expanded databases. Appropriately selected articles were independently reviewed and data was extracted and cross referenced. A meta-analysis was conducted of the pooled trial data to determine difference in outcomes. Results. A total of seven randomized trials were identified with 746 patients with 366 in the laparoscopic only treatment group and 380 in the combined endoscopic and laparoscopic treatment arms. There was no significant difference in successful bile duct clearance between the two groups (OR 1.23; 95% CI 0.55 to 2.75, P = 0.61). There was no statistical difference in morbidity (RR 1.23; 95% CI 0.92 to 1.66; P = 0.17), mortality (RD -0.00; 95% CI -0.02 to 0.01, P = 0.59) or length of hospital stay (MD -0.31; 95% CI -1.68 to 1.06, P = 0.66). However, there was a statistically significant difference in the duration of procedure in favour of the single stage laparoscopic treatment (MD -6.83; 95% CI -9.59 to -4.07, P \u3c 0.00001). Conclusion. Both the laparoscopic alone or the combined endoscopic and laparoscopic treatment approaches show comparative efficacy in management of symptomatic gallstones with associated choledocholithiasis

    Pengendalian Biaya Dan Waktu Dengan Metode Analisis Nilai Dan Hasil Dengan Microsoft Project 2010 (Studi Kasus : Gedung Mantos Tahap III)

    Get PDF
    Pengendalian dalam proyek merupakan fungsi paling pokok dama pelaksanaan suatu proyek konstruksi. Pengendalian sebagai alat untuk membantu mengendalikan proyek, membantu pelaksanaan dan penyelesaian dalam suatu proyek konstruksi. Pelaksanaan suatu proyek umumnya sering terjadi penyimpanan – penyimpangan dimana biaya yang dikeluarkan dan jadwal yang direncanakan melampaui batas yang direncanakan. Pengendalian proyek bertujuan untuk mengendaliakn biaya dan waktu agar sesuai dengan biaya dan jadwal yang direncanakan. Metode nilai hasil merupakan pengembangan teknik pengendalian grafik S sampai mampu menganalisis varians biaya secara stimulant sehingga dapat melihat kemajuan proyek dari jadwal dengan anggaran yang telah dialokasikan. Metode nilai hasil ini mencakup rencana anggaran dan biaya (RAB), daftar harga satuan upah dan bahan, analisa harga satuan serta laporan kemajuan proyek di olah untuk mendapatkan BCWS (Budgeted Cost of Work Schedule), ACWP (Actual Cost of Work Performance) dan BCWP (Budgeted Cost of Work Performance) Dari hasil penerapan metode konsep nilai hasil diketahui sampai hasil tinjauan pada minggu ke 6 di dapatkan BCWS = Rp. 46,932,747,947.29; ACWP = Rp. 45,928,815,000.00; BCWP = Rp. 47,633,716,500.77; sedangkan varian biaya (CV) pada bulan satu sampai tiga adalah negative (-) dan pada bulan ke empat sampai akhir pelaksanaan proyek adalah positif (+) begitu pun varian jadwal. Dan dapat diketahui prakiraan biaya akhir proyek EAC (Estimate At Complection) adalah Rp. 70,829,440,000.00, dengan anggaran rencana sebesar Rp. 72,391,666,414.54. Estimate Complection Date (ECD) proyek mengalami sedikit kemajuan terhadap jadwal yang direncanakan yaitu 2 har

    On computational irreducibility and the predictability of complex physical systems

    Full text link
    Using elementary cellular automata (CA) as an example, we show how to coarse-grain CA in all classes of Wolfram's classification. We find that computationally irreducible (CIR) physical processes can be predictable and even computationally reducible at a coarse-grained level of description. The resulting coarse-grained CA which we construct emulate the large-scale behavior of the original systems without accounting for small-scale details. At least one of the CA that can be coarse-grained is irreducible and known to be a universal Turing machine.Comment: 4 pages, 2 figures, to be published in PR

    The Clumping Transition in Niche Competition: a Robust Critical Phenomenon

    Full text link
    We show analytically and numerically that the appearance of lumps and gaps in the distribution of n competing species along a niche axis is a robust phenomenon whenever the finiteness of the niche space is taken into account. In this case depending if the niche width of the species σ\sigma is above or below a threshold σc\sigma_c, which for large n coincides with 2/n, there are two different regimes. For σ>sigmac\sigma > sigma_c the lumpy pattern emerges directly from the dominant eigenvector of the competition matrix because its corresponding eigenvalue becomes negative. For σ</sigmac\sigma </- sigma_c the lumpy pattern disappears. Furthermore, this clumping transition exhibits critical slowing down as σ\sigma is approached from above. We also find that the number of lumps of species vs. σ\sigma displays a stair-step structure. The positions of these steps are distributed according to a power-law. It is thus straightforward to predict the number of groups that can be packed along a niche axis and it coincides with field measurements for a wide range of the model parameters.Comment: 16 pages, 7 figures; http://iopscience.iop.org/1742-5468/2010/05/P0500

    Meta-analiza učinkovitosti laparoskopskog liječenja u jednom aktu u usporedbi s endoskopskim liječenjem simptomatskih žučnih kamenaca i žučnih kamenaca u glavnom žučovodu u više akata

    Get PDF
    Background The optimal treatment of gallstones with associated common bile duct stones in the laparoscopic era is controversial. Various reviews and decision based algorithms have been published, but the superior treatment modality is unclear. Therefore, a meta-analysis was conducted to compare the two most commonly used treatment strategies. Methods A systematic review was conducted to compare single stage laparoscopic cholecystectomy with common bile duct exploration versus a combined endoscopic and laparoscopic treatment. Eligible studies were identified using a search of Medline, Embase, Cochrane and Science Citation Index Expanded databases. Appropriately selected articles were independently reviewed and data was extracted and cross referenced. A meta-analysis was conducted of the pooled trial data to determine difference in outcomes. Results A total of seven randomized trials were identified with 746 patients with 366 in the laparoscopic only treatment group and 380 in the combined endoscopic and laparoscopic treatment arms. There was no significant difference in successful bile duct clearance between the two groups (OR 1.23; 95% CI 0.55 to 2.75, P = 0.61). There was no statistical difference in morbidity (RR 1.23; 95% CI 0.92 to 1.66; P = 0.17), mortality (RD -0.00; 95% CI -0.02 to 0.01, P = 0.59) or length of hospital stay (MD -0.31; 95% CI -1.68 to 1.06, P = 0.66). However, there was a statistically significant difference in the duration of procedure in favour of the single stage laparoscopic treatment (MD -6.83; 95% CI -9.59 to -4.07, P < 0.00001). Conclusion Both the laparoscopic alone or the combined endoscopic and laparoscopic treatment approaches show comparative efficacy in management of symptomatic gallstones with associated choledocholithiasis.Pozadina Optimalno liječenje žučnih kamenaca uz prateće žučne kamence u glavnom žučovodu u eri laparoskopske kirurgije je kontroverzno. Objavljeni su razni pregledni radovi i algoritmi odlučivanja, no pitanje odluke o odabiru preporučenog načina liječenja ostaje neriješeno. S ciljem usporedbe dva najčešće korištena načina liječenja provedena je meta-analiza. Metode Sistematsko istraživanje provedeno je kako bi se usporedila kolecistektomija s eksploracijom glavnog žučovoda u jednom aktu u odnosu na kombinirano endoskopsko i laparoskopsko liječenje. Dostupne studije nađene su pomoću sljedećih baza podataka: Medline, Embase, Cochrane i Science Citation Index Expanded. Probrani relevantni radovi zasebno su pregledani, a podaci izdvojeni i međusobno uspoređeni. Provedena je meta-analiza svih prikupljenih podataka da bi se odredila razlika u ishodima. Rezultati Pronađeno je sveukupno sedam randomiziranih studija sa 746 pacijenata od kojih je 366 u skupini liječenoj isključivo laparoskopski te 380 liječenih kombinirano endoskopski i laparoskopski. Nije utvrđena značajna razlika u uspješnom čišćenju žučnih vodova između dvije skupine (OR 1,23; 95% CI 0,55 do 2,75, P = 0,61). Nije nađena značajna razlika u morbiditetu (RR 1,23; 95% CI 0,92 do 1,66; P = 0,17), smrtnosti (RD -0,00; 95% CI -0.02 do 0,01, P = 0,59) ili trajanju hospitalizacije (MD -0,31; 95% CI -1,68 to 1,06, P = 0,66). Međutim, postojala je statistički značajna razlika u trajanju zahvata (MD -6,83; 95% CI -9,59 do -4,07, P < 0,00001). Zaključak Laparoskopski ili kombinirani endoskopski i laparoskopski pristup liječenju pokazuje značajnu učinkovitost u liječenju simptomatskih žučnih kamenaca s pratećom koledoholitijazom

    A model for the induction of chromosome aberrations through direct and bystander mechanisms

    Get PDF
    A state vector model (SVM) for chromosome aberrations and neoplastic transformation has been adapted to describe detrimental bystander effects. The model describes initiation (formation of translocations) and promotion (clonal expansion and loss of contact inhibition of initiated cells). Additional terms either in the initiation model or in the rate of clonal expansion of initiated cells, describe detrimental bystander effects for chromosome aberrations as reported in the scientific literature. In the present study, the SVM with bystander effects is tested on a suitable dataset. In addition to the simulation of non-linear effects, a classical dataset for neoplastic transformation in C3H 10T1/2 cells after alpha particle irradiation is used to show that the model without bystander features can also describe LNT-like dose responses. A published model for bystander induced neoplastic transformation was adapted for chromosome aberration induction and used to compare the results obtained with the different models

    Detrimental and Protective Bystander Effects: A Model Approach

    Get PDF
    This work integrates two important cellular responses to low doses, detrimental bystander effects and apoptosis-mediated protective bystander effects, into a multistage model for chromosome aberrations and in vitro neoplastic transformation: the State-Vector Model. The new models were tested on representative data sets that show supralinear or U-shaped dose responses. The original model without the new low-dose features was also tested for consistency with LNT-shaped dose responses. Reductions of in vitro neoplastic transformation frequencies below the spontaneous level have been reported after exposure of cells to low doses of low-LET radiation. In the current study, this protective effect is explained with by-stander-induced apoptosis. An important data set that shows a low-dose detrimental bystander effect for chromosome aberrations was successfully fitted by additional terms within the cell initiation stage. It was found that this approach is equivalent to bystander-induced clonal expansion of initiated cells. This study is an important step toward a comprehensive model that contains all essential biological mechanisms that can influence dose–response curves at low doses

    Gauge invariance and finite width effects in radiative two-pion tau lepton decay

    Full text link
    The contribution of the rho^{\pm} vector meson to the tau -> pi pi nu gamma decay is considered as a potential source for the determination of the magnetic dipole moment of this light vector meson. In order to keep gauge-invariance of the whole decay amplitude, a procedure similar to the fermion loop-scheme for charged gauge bosons is implemented to incorporate the finite width effects of the rho^{\pm} vector meson. The absorptive pieces of the one-loop corrections to the propagators and electromagnetic vertices of the rho^{\pm} meson and W^{\pm} gauge boson have identical forms in the limit of massless particles in the loops, suggesting this to be a universal feature of spin-one unstable particles. Model-dependent contributions to the tau -> pi pi nu gamma decay are suppressed by fixing the two-pion invariant mass distribution at the rho meson mass value. The resulting photon energy and angular distribution is relatively sensitive to the effects of the rho magnetic dipole moment.Comment: 22 pages, 4 postscript figures, references and comments on relevance of perturbative treatment of rho electromagnetic vertex are added, accepted for pub. in Phys. Rev.
    corecore