115,127 research outputs found
A General Framework for Constraint-Based Static Analyses of Java Bytecode Programs
No full textQuesta tesi introduce un generico e parametrizzato framework per analisi statica dei programmi Java bytecode, basato sulla generazione e soluzione dei vincoli. All'interno del framework è possibile gestire sia i flussi di eccezione all'interno di programmi analizzati, sia i side-effect indotti dalle esecuzioni dei metodi che possono modificare la memoria. Questo framework è generico nel senso che diverse istanziazioni dei suoi parametri risultano in diverse analisi statiche capaci di catturare varie proprietà relative alla memoria delle variabili del programma ad ogni punto del programma. Le analisi statiche definite dal framework sono basate su interpretazione astratta, e quindi le proprietà d'interesse sono rappresentate da dei domini astratti. Il framework può essere usato per la definizione sia delle analisi statiche che producono le approssimazioni del tipo "possible" oppure "may", che quelle del tipo "definite" oppure "must". Nel primo caso, il risultato di tali analisi è una sovra-approssimazione di quello che potrebbe essere vero ad un certo punto del programma, mentre nel secondo caso il risultato rappresenta una sotto-approssimazione della situazione reale. Questa tesi fornisce un insieme di condizioni che diverse istanziazioni dei parametri del framework devono soddisfare affinché le analisi statiche definite all'interno del framework siano "sound" (corrette). Quando i parametri istanziati soddisfano tali condizioni, il framework garantisce la correttezza dell'analisi corrispondente all'istanziazione in questione. Il vantaggio di questo approccio è che il designer di una nuova analisi statica deve soltanto mostrare che i parametri da lui istanziati soddisfano i criteri specificati dal framework.In questo modo la dimostrazione di correttezza dell'analisi completa è semplificata. Questa è una caratteristica molto importante del presente lavoro.
La tesi introduce due nuove analisi statiche relatve alle proprietà della memoria: la Possible Reachability Analysis Between Program Variables e la Definite Expression Aliasing Analysis. La prima rappresenta un esempio delle analisi "possible" e determina, per ogni punto p del programma, quali sono le coppie ordinate delle variabili disponibili a tale punto, tali che v potrebbe raggiungere w al punto p, ovvero, che a partire dalla variabile v è possibile seguire un insieme di locazioni di memoria che portano all'oggetto legato alla variabile w. La seconda analisi è un esempio delle analisi "definite" e determina, per ogni punto p del programma ed ogni variabile v disponibile a tale punto, un insieme di espressioni il cui valore è sempre uguale al valore che la variabile v può avere al punto p, per ogni possibile esecuzione. Entrambe le analisi sono state formalizzate e dimostrate corrette grazie ai risultati teorici del framework introdotto in questa tesi. In più, entrambe le analisi sono state implementate all'interno dell'analizzatore statico per Java e Android chiamato Julia (www.juliasoft.com). Gli esperimenti eseguiti sui programmi reali mostrano che la precisione dei principali tool di Julia (nullness e termination tool) è migliorata rispetto alle versioni precedenti di Julia nelle quali le nuove analisi non erano presenti.The present thesis introduces a generic parameterized framework for static analysis of Java bytecode programs, based on constraint generation and solving. This framework is able to deal with the exceptional flows inside the program and the side-effects induced by calls to non-pure methods. It is generic in the sense that different instantiations of its parameters give rise to different static analyses which might capture complex memory-related properties at each program point. Different properties of interest are represented as abstract domains, and therefore the static analyses defined inside the framework are abstract interpretation-based. The framework can be used to generate possible or may approximations of the property of interest, as well as definite or must approximations of that property. In the former case, the result of the static analysis is an over-approximation of what might be true at a given program point; in the latter, it is an under-approximation. This thesis provides a set of conditions that different instantiations of framework's parameters must satisfy in order to have a sound static analysis. When these conditions are satisfied
by a parameter's instantiation, the framework guarantees that the corresponding static analysis is sound. It means that the designer of a novel static analysis should only show that the parameters he or she instantiated actually satisfy the conditions provided by the framework. This way the framework simplifies the proofs of soundness of the static analysis: instead of showing that the overall analysis is sound, it is enough to show that the provided instantiation describing the actual static analyses satisfies the conditions mentioned above. This a very important feature of the present approach.
Then the thesis introduces two novel static analyses dealing with memory-related properties: the Possible Reachability Analysis Between Program Variables and the Definite Expression Aliasing Analysis. The former analysis is an example of a possible analysis which determines, for each program point p, which are the ordered pairs of variables available at p, such that v might reach w at p, i.e., such that starting from v it is possible to follow a path of memory locations that leads to the object bound to w. The latter analysis is an example of a definite analysis, and it determines, for each program point p and each variable v available at that point, a set of expressions which are always aliased to v at p. Both analyses have been formalized and proved sound by using the theoretical results of the framework. These analyses have been also implemented inside the Julia tool (www.juliasoft.com), which is a static analyzer for Java and Android. Experimental evaluation of these analyses on real-life benchmarks shows how the precision
of Julia's principal checkers (nullness and termination checkers) increased compared to the previous version of Julia where these two analyses were not implemented. Moreover, this experimental evaluation showed that the presence of the reachability analysis actually decreased the total run-time of Julia. On the other hand, the aliasing analysis takes more time, but the number of possible warnings produced by the principal checkers drastically decreased
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Going 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
Mesoscopic diode
No full textHere we discuss the possibility of an alternative rectifying structure which operates in the world of mesoscopic devices. A simple quantum constriction (wide–narrow geometry) is found to act as a rectifier in the coherent transport regime if Fermi energy is between the propagation thresholds of the wide and narrow parts. Also a quantum structure is proposed which is predicted to operate as a rectifier at room temperatures. This diode for the nanostructures is a quantum wire with an asymmetric quantum constriction (AQC) which works in the coherent transport regime. Structurally imperfect mesoscopic diodes retain rectifying features, although the actual I–V characteristics are different in comparison to the perfect devices
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Uptake of iron (Fe-59) complexed to water-extractable humic substances by sunflower leaves
No full textA research was carried out to evaluate the leaves' ability to utilize Fe supplied as a complex with water-extractable humic substances (WEHS) and the long-distance transport of 59Fe applied to sections of fully expanded leaves of intact sunflower (Helianthus annuus L.) plants. Plants were grown in a nutrient solution containing 10 μM Fe(III)-EDDHA (Fe-sufficient plants), with the addition of 10 mM NaHCO3 to induce iron chlorosis (Fe-deficient plants). Fe(III)-WEHS could be reduced by sunflower leaf discs at levels comparable to those observed using Fe(III)-EDTA, regardless of the Fe status. On the other hand, 59Fe uptake rate by leaf discs of green and chlorotic plants was significantly lower in Fe-WEHS-treated plants, possibly suggesting the effect of light on photochemical reduction of Fe-EDTA. In the experiments with intact plants, 59Fe-labeled Fe-WEHS or Fe-EDTA were applied onto a section of fully expanded leaves. Irrespective of Fe nutritional status, 59Fe uptake was significantly higher when the treatment was carried out with Fe-EDTA. A significant difference was found in the amount of 59Fe translocated from treated leaf area between green and chlorotic plants. However, irrespective of the Fe nutritional status, no significant difference was observed in the absolute amount of 59Fe translocated to other plant parts when the micronutrient was supplied either as Fe-EDTA or Fe-WEHS. Results show that the utilization of Fe complexed to WEHS by sunflower leaves involves an Fe(III) reduction step in the apoplast prior to its uptake by the symplast of leaf cells and that Fe taken up from the Fe-WEHS complexes can be translocated from fully expanded leaves towards the roots and other parts of the shoot
Germination Response of Datura stramonium L. to Different pH and Salinity Levels under Different Temperature Conditions
No full text: Weeds can be one of the most severe threats to crop production, especially when they are widespread and highly adaptable. Part of the adaptive strategy of plants is the ability to germinate in different conditions. Germination is the first developmental phase of plant life and is fundamental for its establishment. In this work, the germination of two populations of Datura stramonium L. at two different sites in Croatia (one cropped, the other non-agricultural) was tested under a wide range of salinity stress, 4, 8, 12, and 16 dS/m, and pH stress, values 1-9, at two temperature ranges of 15-25 °C and 18-30 °C. The results show that this species can tolerate high salinity, with a high number of seeds germinating, even under the highest level of saline stress and especially at higher temperatures: 21.7% of seeds germinated at 15-25 °C and 51.2% at 18-30 °C. D. stramonium also appears to be quite acid tolerant, with a significant reduction in germination only at pH 2, and no germination only at pH 1. Germination was always higher at higher temperatures, independently of abiotic stress. Although there were some differences between the two populations in the final germination percentages, they were similar in their responses to the abiotic stresses
The nonlinear transport regime of a T‐shaped quantum interference transistor
No full textWe present the current–voltage characteristics of a T‐shaped semiconductor electron waveguide structure in the nonlinear regime. This system is interesting as a potential quantum interference transistor. Calculated zero‐temperature I–V characteristics are with multiple peaks and exhibit regions of negative‐differential resistance. The peak‐to‐valley ratio has maximum value of 3:1. The calculated values of the transconductance and the differential drain conductance are small, which suggests limited abilities for conventional applications of the transistor
Autoimmune pancreatitis : from bench to bedside
No full textBackground: Decreased microbial diversity had been associated with the establishment of an environment in which pathogens could incite and sustain chronic inflammation. Metabolomic analysis of fecal samples provides insights into the gut microbiome's interaction with the host's metabolism. Autoimmune pancreatitis (AIP) is a complex immune-mediated form of chronic pancreatitis, comprising two distinct entitiesŃType 1 and Type 2Ńwith differing histological features, clinical presentations, and prognoses. AIP type 1 is a systemic disease, while type 2 is strongly associated with inflammatory bowel disease. Diagnosing AIP is challenging, relying on a set of criteria rather than a definitive diagnostic marker, and requires the exclusion of pancreatic cancer before proceeding. Management backbone are glucocorticoids, with excellent response. Relapses and often in type 1 AIP and different strategies for relapse treatment are possible including advanced therapies. Pancreatic exocrine and endocrine insufficiencies are consequences of inflammatory damage but are considered transient.Aims: This thesis aims to enhance the scientific evidence surrounding the diagnosis, treatment, and follow-up of AIP patients by examining the relationship between pharmacological treatment and loss of pancreatic function in type 1 AIP, evaluating the outcomes of patients treated surgically and with advanced therapies, and investigating the association between type 2 AIP and IBD. Additionally, the thesis explores gut metabolic changes in AIP and identifies key metabolites associated with the disease.Methods: The thesis comprises four epidemiological studies (Studies I-IV) and one metabolomic study (Study V) on AIP patients followed at Karolinska University Hospital in Stockholm, Sweden, from 2001-2022. The epidemiological studies are retrospective cohort studies based on medical records, with systematic reviews conducted in Studies II and IV. In Study V, fecal samples were collected from patients, and after obtaining informed consent, the samples underwent UHPLCĐ MS/MS analysis for metabolite identification.Results: In Study I, prevalence of pancreatic exocrine insufficiency at diagnosis was 72.7% and 63.5% at follow-up. The cumulative incidence of diabetes mellitus was 17.9%, with a prevalence of diabetes mellitus at diagnosis of 32.8%. No strong association was found between pharmacological treatment and occurrence of pancreatic exocrine insufficiency and diabetes mellitus. In a multivariate analysis, only obstructive jaundice was identified as a risk factor for diabetes mellitus both at diagnosis and during follow-up. Study II showed that twelve (11.7%) of 103 patients with AIP type 1 were treated with rituximab during the study period: eight (66.7%) achieved complete and four (33.3%) partial remission. Rituximab was discontinued in one patient who developed fever and reactivation of latent tuberculosis. Altogether, eight studies with 110 AIP type-1 patients treated with rituximab were analyzed. Adverse effects ranged from 11Đ43% and the relapsefree period during follow-up ranged from 38Đ94%. Study III reported that 35 (22.0%) patients with AIP had surgery. Malignant and premalignant lesions were diagnosed in 8 (22.9%) patients for whom AIP was not the primary differential diagnosis, but in all cases, it was described as a simultaneous finding. One third of AIP type 1 patients experienced relapse in the follow up after surgery. Study IV revealed that diagnosis of inflammatory bowel disease was reported in 330 (47.8%) patients of our systematic review, whereas in 29/35 (83%) of AIP type 2 patients in our cohort. The relapse rate was 20.0% in both original and systematic analysis. Study V led to the discovery of newly identified metabolic signatures between both patient groups with enterolactone being prominent in AIP.Conclusion: Prevalence of endocrine and exocrine insufficiency in AIP is high at diagnosis with an additional risk during follow-up despite pharmacological treatment. Obstructive jaundice is a risk factor for diabetes mellitus both at diagnosis and at follow up. Rituximab is effective in inducing and maintaining remission in relapsing AIP type 1. Surgical treatment is justified where cancer cannot be excluded, although relapse risk is not annihilated. Clinical and radiological remission of AIP type 2 is high, while the cumulative incidence of relapse is around 20%. Concomitance of inflammatory bowel disease imposes no obvious risk of a different disease course for AIP type 2.List of scientific papersI. Nikolic S, Maisonneuve P, Dahlman I, Lšhr JM, Vujasinovic M. Exocrine and Endocrine Insufficiency in Autoimmune Pancreatitis: A Matter of Treatment or Time?. J Clin Med. 2022;11(13):3724. Published 2022 Jun 28. https://doi.org/10.3390/jcm11133724 II. Nikolic S, Panic N, Hintikka ES, et al. Efficacy and safety of rituximab in autoimmune pancreatitis type 1: our experiences and systematic review of the literature. Scand J Gastroenterol. 2021;56(11):1355-1362. https://doi.org/10.1080/00365521.2021.1963837 III. Nikolic S, Ghorbani P, Pozzi Mucelli R, et al. Surgery in Autoimmune Pancreatitis. Dig Surg. 2022;39(1):32-41. https://doi.org/10.1159/000521490 IV. Nikolic S, Lanzillotta M, Panic N, et al. Unraveling the relationship between autoimmune pancreatitis type 2 and inflammatory bowel disease: Results from two centers and systematic review of the literature. United European Gastroenterol J. 2022;10(5):496-506. https://doi.org/10.1002/ueg2.12237 V. Dovhalyuk V, Yang F, Nikolic S et al. Differences in the Fecal Metabolome of Autoimmune Pancreatitis Patients. [Manuscript]</p
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