170,623 research outputs found
Guide to Good Practice in using Open Source Compilers with the AGCC Lexical Analyzer
No full textQuality software always demands a compromise between users' needs and hardware resources. To be faster means expensive devices like powerful processors and virtually unlimited amounts of RAM memory. Or you just need reengineering of the code in terms of adapting that piece of software to the client's hardware architecture. This is the purpose of optimizing code in order to get the utmost software performance from a program in certain given conditions. There are tools for designing and writing the code but the ultimate tool for optimizing remains the modest compiler, this often neglected software jewel the result of hundreds working hours by the best specialists in the world. Even though, only two compilers fulfill the needs of professional developers, a proprietary solution from a giant in the IT industry, and the Open source GNU compiler, for which we develop the AGCC lexical analyzer that helps producing even more efficient software applications. It relies on the most popular hacks and tricks used by professionals and discovered by the author who are proud to present them further below.registers, dynamic linkage, cache, null pointers, tweaking
Microbial biodiversity and viral impact in benthic deep-sea ecosystems
No full textGli ambienti marini profondi ricoprono il 95% del globo terrestre e sono caratterizzati da basse temperature, assenza di luce ed elevate pressioni. Tra i sistemi marini profondi i più remoti e inesplorati sono le fosse adali, sistemi che possono superare gli 11000 m di profondità. Lo studio di questi ambienti estremi rappresenta una delle più grandi sfide della ricerca scientifica a causa delle difficoltà che si presentano nel raggiungerli. Questo studio fornisce i primi dati riguardanti l’impatto dei virus sui procarioti che abitano i sedimenti di tre tra le più profonde fosse oceaniche conosciute, Japan, Ogasawara e Mariana. In questo studio abbiamo esplorato il ruolo dei virus come agenti di mortalità procariotica, in grado di influenzare i cicli di C e nutrienti tramite la lisi cellulare dei loro ospiti contribuendo così al funzionamento delle reti trofiche microbiche e al funzionamento ecosistemico degli ambienti profondi. I nostri risultati rivelano che tutte le fosse adali qui investigate supportano elevate abbondanze e biomasse procariotiche favorendo alti tassi di lisi virale e stimolando il rilascio di materia organica resa così disponibile per le comunità bentoniche. Specialmente nella fossa Mariana la lisi virale è potenzialmente esercitata con maggiore pressione sui taxa microbici dominanti influenzando la struttura della rete trofica microbica e i cicli di C e N, e contribuendo così all’elevato metabolismo procariotico precedentemente riconosciuto in questi sistemi ultra abissali. Oltre alle interazioni microbiche, in questo studio è stata esplorata la diversità delle comunità procariotiche presenti nelle fosse investigate ed è stato determinato l’importante contributo della componente archaeale alla struttura di queste comunità. Il predominio di archaea ammonio-ossidanti suggerisce che i processi chemoautotrofici presentano un ruolo chiave per il funzionamento delle fosse adali. Inoltre, l’elevato numero di taxa, ritrovato specialmente nella fossa Japan, rivela che gli ecosistemi delle fosse adali possono rappresentare hot spot di diversità procariotica. In aggiunta, la presenza di taxa procariotici diffusi in habitat abissali bentonici suggerisce che le fosse adali sono solo parzialmente connesse agli ecosistemi bentonici circostanti.
In questo studio abbiamo anche investigato le risposte, su diverse scale temporali, delle comunità microbiche abissali (interazioni virus-procarioti e diversità batterica) all’impatto dell’attività di estrazione di risorse minerarie, che rappresenta una delle future minacce tra le più impattanti per questi ambienti. I risultati ottenuti indicano un aumento dei tassi d’infezione virale sulla componente batterica potenzialmente dovuto ad una cambiamento della composizione in specie di tale componente a seguito dell’attività di mining, anche molti anni dopo l’impatto e con potenziali conseguenze sui cicli biogeochimici e sul funzionamento ecosistemico bentonico
Complexity-preserving simulations among three variants of accepting networks of evolutionary processors
No full textIn this paper we consider three variants of accepting networks of evolutionary processors. It is known that two of them are equivalent to Turing machines. We propose here a direct simulation of one device by the other. Each computational step in one model is simulated in a constant number of computational steps in the other one while a translation via Turing machines squares the time complexity. We also discuss the possibility of constructing simulations that preserve not only complexity, but also the shape of the simulated network. © 2011 Springer Science+Business Media B.V.This work was supported by the Academy of Finland, projects 132727, 122426, and 108421. F. Manea acknowledges the support from the Alexander von Humboldt Foundation. J Sempere acknowledges the support from the Spanish Ministerio de Educacion y Ciencia project TIN2007-60769.Bottoni ., P.; Labella ., A.; Manea ., F.; Mitrana, V.; Petre ., I.; Sempere Luna, JM. (2011). Complexity-preserving simulations among three variants of accepting networks of evolutionary processors. Natural Computing. 10(1):429-445. https://doi.org/10.1007/s11047-010-9238-5S429445101Alhazov A, Bel Enguix G, Rogozhin Y (2009a) Obligatory hybridnetworks of evolutionary processors. In: International conference on agents and artificial intelligence (ICAART 2009), pp 613–618Alhazov A, Csuhaj-Varj E, Martn-Vide C, Rogozhin Y (2009b) On the size of computationally complete hybrid networks ofevolutionaryprocessors. Theor Comput Sci 410:3188–3197Bottoni P, Labella A, Manea F, Mitrana V, Sempere J (2009a) Filter position in networks of evolutionary processors does not matter: a direct proof. In: Proc. 15th international meeting on DNA computing and molecular programming. 8–11 June 2009, Fayetteville, ArkansasBottoni P, Labella A, Mitrana V, Sempere JM (2009b) Networks of evolutionary picture processors with filtered connections. In: Unconventional computation, 8th international conference (UC 2009), LNCS, vol 5715. Springer, Heidelberg, pp 70–84Castellanos J, Martín-Vide C, Mitrana V, Sempere J (2001) Solving NP-complete problems with networks of evolutionary processors. In: International work-conference on artificial and natural neural networks (IWANN 2001), Lecture notes in computer science, vol 2084, pp 621–628Csuhaj-Varjú E, Mitrana V (2000) Evolutionary systems: a language generating device inspired by evolving communities of cells. Acta Inform 36:913–926Csuhaj-Varjú E, Salomaa A (1997) Networks of parallel language processors. In: New trends in formal languages, Lecture notes in computer science, vol 1218, pp 299–318Dassow J, Truthe B (2007) On the power of networks of evolutionary processors. In: Machines, computations, and universality (MCU 2007), Lecture notes in computer science, vol 4667, pp 158–169Drăgoi C, Manea F (2008) On the descriptional complexity of accepting networks of evolutionary processors with filtered connections. Int J Found Comput Sci 19:1113–1132Drăgoi C, Manea F, Mitrana V (2007) Accepting networks of evolutionary processors with filtered connections. J Univers Comput Sci 13:1598–1614Errico L, Jesshope C (1994) Towards a new architecture for symbolic processing. In: Artificial intelligence and information-control systems of robots ’94, World Scientific, Singapore, pp 31–40Fahlman SE, Hinton GE, Seijnowski TJ (1983) Massively parallel architectures for AI: NETL, THISTLE and Boltzmann machines. In: Proc. of the national conference on artificial intelligence, pp 109–113Hillis W (1985) The connection machine. MIT Press, CambridgeManea F, Martin-Vide C, Mitrana V (2007) On the size complexity of universal accepting hybrid networks of evolutionary processors. Math Struct Comput Sci 17:753–771Margenstern M, Mitrana V, Perez-Jimenez M (2005) Accepting hybrid networks of evolutionary systems. In: DNA based computers 10, Lecture notes in computer science, vol, pp 235–246Martín-Vide C, Mitrana V (2005) Networks of evolutionary processors: results and perspectives. In: Molecular computational models: unconventional approaches. dea Group Publishing, Hershey, pp 78–114Păun G (2000) Computing with membranes. J Comput Syst Sci 61:108–143Păun G, Sântean L (1989) Parallel communicating grammar systems: the regular case. Ann Univ Bucharest Ser Matematica Inform 38:55–63Rozenberg G, Salomaa A (eds) (1997) Handbook of formal languages. Springer–Verlag, BerlinSankoff D et al. (1992) Gene order comparisons for phylogenetic inference: evolution of the mitochondrial genome. Proc Natl Acad Sci USA 89:6575–657
Extracellular DNA as a genetic recorder of microbial diversity in benthic deep-sea ecosystems
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A feasibility study to estimate global prevalence of intentional injuries impact on human communities
No full textALPIDE for space applications: Power consumption
No full textALPIDE, a monolithic active pixel sensor developed for the ALIDE Inner Tracker upgrade, is studied as possible sensor unit for a space-borne particle tracker. The aspect of power consumption and heat dissipation is investigated
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
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