Degree Ranking Using Local Information

Most real world dynamic networks are evolved very fast with time. It is not feasible to collect the entire network at any given time to study its characteristics. This creates the need to propose local algorithms to study various properties of the network. In the present work, we estimate degree rank of a node without having the entire network. The proposed methods are based on the power law degree distribution characteristic or sampling techniques. The proposed methods are simulated on synthetic networks, as well as on real world social networks. The efficiency of the proposed methods is evaluated using absolute and weighted error functions. Results show that the degree rank of a node can be estimated with high accuracy using only $1\%$ samples of the network size. The accuracy of the estimation decreases from high ranked to low ranked nodes. We further extend the proposed methods for random networks and validate their efficiency on synthetic random networks, that are generated using Erd\H{o}s-R\'{e}nyi model. Results show that the proposed methods can be efficiently used for random networks as well

A Faster Method to Estimate Closeness Centrality Ranking

Closeness centrality is one way of measuring how central a node is in the given network. The closeness centrality measure assigns a centrality value to each node based on its accessibility to the whole network. In real life applications, we are mainly interested in ranking nodes based on their centrality values. The classical method to compute the rank of a node first computes the closeness centrality of all nodes and then compares them to get its rank. Its time complexity is $O(n \cdot m + n)$, where $n$ represents total number of nodes, and $m$ represents total number of edges in the network. In the present work, we propose a heuristic method to fast estimate the closeness rank of a node in $O(\alpha \cdot m)$ time complexity, where $\alpha = 3$. We also propose an extended improved method using uniform sampling technique. This method better estimates the rank and it has the time complexity $O(\alpha \cdot m)$, where $\alpha \approx 10-100$. This is an excellent improvement over the classical centrality ranking method. The efficiency of the proposed methods is verified on real world scale-free social networks using absolute and weighted error functions

Making Sense of Email Addresses on Drives

Drives found during investigations often have useful information in the form of email addresses, which can be acquired by search in the raw drive data independent of the file system. Using these data, we can build a picture of the social networks in which a drive owner participated, even perhaps better than investigating their online profiles maintained by social-networking services, because drives contain much data that users have not approved for public display. However, many addresses found on drives are not forensically interesting, such as sales and support links. We developed a program to filter these out using a Naïve Bayes classifier and eliminated 73.3% of the addresses from a representative corpus. We show that the byte-offset proximity of the remaining addresses found on a drive, their word similarity, and their number of co-occurrences over a corpus are good measures of association of addresses, and we built graphs using this data of the interconnections both between addresses and between drives. Results provided several new insights into our test data

Making Sense of Email Addresses on Drives

Drives found during investigations often have useful information in the form of email addresses which can be acquired by search in the raw drive data independent of the file system. Using this data we can build a picture of the social networks that a drive owner participated in, even perhaps better than investigating their online profiles maintained by social-networking services because drives contain much data that users have not approved for public display. However, many addresses found on drives are not forensically interesting, such as sales and support links. We developed a program to filter these out using a Naïve Bayes classifier and eliminated 73.3% of the addresses from a representative corpus. We show that the byte-offset proximity of the remaining addresses found on a drive, their word similarity, and their number of co-occurrences over a corpus are good measures of association of addresses, and we built graphs using this data of the interconnections both between addresses and between drives. Results provided several new insights into our test data

Growth Kinetics and Production of Glucose Oxidase Using Aspergillus niger NRRL 326

In this paper, we demonstrate the substrate inhibition phenomena for growth kinetics of Aspergillus niger NRRL 326 grown on sucrose during glucose oxidase production. The initial set of experiments were carried out using three different substrates, viz., glucose, sucrose and raffinose of which it was observed that sucrose serves better for higher production of glucose oxidase. Experiments involving sensitivity studies conveyed that substrate inhibition became predominant when sucrose mass concentration was above γ = 30 g L-1 in the cultivation medium. The later part of the work was dovetailed towards validation of substrate inhibited growth kinetics with established models such as Haldane, Andrews, Luong, Han-Levenspiel and Aiba. Finally, it was observed that none of the classical models explains the kinetics well

Growth Kinetics and Production of Glucose Oxidase Using Aspergillus niger NRRL 326

In this paper, we demonstrate the substrate inhibition phenomena for growth kinetics of Aspergillus niger NRRL 326 grown on sucrose during glucose oxidase production. The initial set of experiments were carried out using three different substrates, viz., glucose, sucrose and raffinose of which it was observed that sucrose serves better for higher production of glucose oxidase. Experiments involving sensitivity studies conveyed that substrate inhibition became predominant when sucrose mass concentration was above γ = 30 g L-1 in the cultivation medium. The later part of the work was dovetailed towards validation of substrate inhibited growth kinetics with established models such as Haldane, Andrews, Luong, Han-Levenspiel and Aiba. Finally, it was observed that none of the classical models explains the kinetics well

Endoscopic resection of sinonasal inverted papilloma: a multivariate retrospective analysis of factors affecting recurrence and persistence

Sinonasal inverted papilloma (IP) is the most common benign epithelial tumor in the nasal cavity and paranasal sinuses, with a worldwide incidence between 0.6 and 1.5/100 000 persons per year. However, only a few studies have investigated patient-dependent factors related to IP recurrence and persistence. According to available evidence, these factors are still debated, and results are contradictory. In this multicenter retrospective study, we analyzed the clinical records of 130 patients who were surgically treated for sinonasal IP to evaluate the factors affecting recurrence and persistence of IP and compared the curative rates of different surgical approaches. Our analysis showed that IP recurrence is strongly related to specific risk factors including incomplete surgical removal, stage of disease, site of the lesion, surgical technique, and malignancy rate. In conclusion, the recurrence of IP may be affected by several risk factors; these factors must be carefully considered during clinical evaluation and especially during the follow-up of patients with IP

Prognostic value of the Sinonasal Outcome Test 22 (SNOT-22) in chronic rhinosinusitis

Studi in letteratura hanno evidenziato che il punteggio basale del Sinonasal Outcome Test 22 (SNOT-22) influenza l\u2019outcome chirurgico nella rinosinusite cronica (CRS) ed hanno suggerito che un approccio SNOT-22-mediato potrebbe migliorare la comprensione delle aspettative dei pazienti dopo il trattamento. Il presente studio mirava a verificare questa ipotesi in una popolazione italiana di CRS. In 457 pazienti con CRS, trattati con chirurgia endoscopica endonasale dopo fallimento della terapia medica massimale, sono stati calcolati la percentuale di raggiungimento della differenza minima clinicamente rilevabile (MCID) e la percentuale di miglioramento relativo dopo l\u2019intervento chirurgico. Inoltre, \ue8 stato studiato l\u2019impatto di diversi fattori sul punteggio dello SNOT-22 preoperatorio e postoperatorio. Il miglioramento dei sintomi si \ue8 verificato nella maggior parte dei pazienti ed era direttamente proporzionale alla SNOT-22 basale. Il 79,7% dei pazienti ha raggiunto l\u2019MCID e la percentuale di miglioramento relativo \ue8 stata del 50,1%. Le implicazioni psicologiche e sociali hanno influenzato significativamente i punteggi dello SNOT-22. Un\u2019analisi di regressione multipla ha mostrato che la storia di precedenti interventi chirurgici, asma, score endoscopico preoperatorio e SNOT-22 basale hanno statisticamente predetto il punteggio dello SNOT-22 postoperatorio (R2 = 0,229). Sottoporre i pazienti con CRS a SNOT-22 prima dei trattamenti chirurgici potrebbe quindi aiutare ad informarli sui probabili esiti, sebbene sia fortemente influenzato dalla percezione individuale. Sono necessari ulteriori studi per identificare un set efficace di parametri soggettivi e oggettivi per la valutazione dei risultati.Previous studies have highlighted that baseline Sinonasal Outcome Test 22 (SNOT-22) score affects surgical outcomes in chronic rhinosinusitis (CRS) and suggested that a SNOT-22- based approach might ameliorate patients\u2019 understanding of expectations after treatment. Our study aimed at verifying this hypothesis in an Italian CRS population. In 457 CRS patients treated with endoscopic sinus surgery after failure of maximal medical therapy, the percentage of achieving a minimal clinically important difference (MCID) and the percentage of relative improvement after surgery were calculated. Moreover, the impact of several factors on preoperative and postoperative SNOT-22 score was investigated. Symptom improvement occurred in the majority of patients and was directly proportional to baseline SNOT-22. 79,7% of patients achieved the MCID and the percentage of relative improvement was 50,1%. Psychological and social-functioning implications significantly affected SNOT-22 scores. Multiple regression analysis showed that history of previous surgery, asthma, preoperative endoscopic and SNOT-22 scores predicted the postoperative SNOT-22 score (R2 = 0,298). Submitting CRS patients to SNOT-22 prior to surgical treatments might help to inform about probable outcomes, although it is strongly influenced by individual perception. Further studies are needed to identify an effective set of subjective and objective parameters for evaluation of outcomes

Glioma-associated protein CHI3L2 suppresses cells viability and induces G1/S transition arrest

Aim. To analyze the effect of the CHI3L2 protein on malignant and non-malignant cell viability, and determined the CHI3L2 impact on the cell cycle and signaling pathways involved in the cell cycle regulation. Methods. MTT-based cell proliferation assay, FACS, western blot analysis. Results. The CHI3L2 protein inhibits the glioma cells viability and potentiates the effect of anti-cancer cytotoxic agents. The CHI3L2 treatment results in the G1/S transition arrest. CHI3L2 provoked a dramatic reduction of pRB phosphorylation and a significant decrease in the cyclin D1 expression, whereas the p53 and p21 expression levels were substantially increased. Conclusions. The CHI3L2 protein, which is overexpressed in human gliomas, is a negative regulator of the glioma cells viability. The reduced cell viability after the CHI3L2 treatment could be due to the activation of pRB and p53 and the downregulation of cyclin D.Мета. Проаналізувати життєздатність злоякісних та незлоякісних клітин за дії протеїна CHI3L2, а також визначити вплив CHI3L2 на клітинний цикл і сигнальні шляхи, залучені до його регуляції. Методи. МТТ–тест, проточна цитофлуориметрія, вестерн блот аналіз. Результати. CHI3L2 пригнічує життєздатність клітин гліоми людини і підсилює дію протиракових цитотоксичних агентів. CHI3L2 інгібує перехід клітин із G1- до S-фази клітинного циклу. CHI3L2 зумовлює зниження кількості фосфорильованої форми pRB, зменшення вмісту цикліну D1 та зростання вмісту p53 і p21. Висновки. CHI3L2, що надекспресується в гліомах людини, є негативним регулятором життєздатності клітин гліоми. Цитотоксичний вплив CHI3L2 може бути пов'язаним з активацією pRB та р53, а також зниженням вмісту цикліну D.Цель. Проанализировать жизнеспособность злокачественных и незлокачественных клеток при воздействии протеина CHI3L2, а также определить влияние CHI3L2 на клеточный цикл и сигнальные пути, вовлеченные в его регуляцию. Методы. МТТ-тест, проточная цитофлуориметрия, вестерн блот анализ. Результаты. CHI3L2 подавляет жизнеспособность клеток глиомы человека и усиливает действие противораковых цитотоксических агентов. CHI3L2 ингибирует переход клеток с G1- в S-фазу клеточного цикла. Влияние CHI3L2 приводит к снижению количества фосфорилированной формы pRB, уменьшению содержания циклина D1 и увеличению содержания p53 и p21. Выводы. CHI3L2, оверэкспрессия которого характерна для глиом человека, является негативным регулятором жизнеспособности клеток глиомы. Цито­ток­си­чес­кое влияние CHI3L2 может быть связано с активацией pRB и р53, а также снижением содержания циклина D

The effect of a centenary storm on the long-lived seagrass Posidonia oceanica

We used the disturbance resulting from a once in a 100‐yr storm on the northwest Mediterranean coast to examine the extent of the disturbance, the tolerance thresholds to burial, and the medium‐term response of the long‐lived Posidonia oceanica seagrass. Sediment burial at 12 surveyed areas was particularly strong in shallow meadows, with 23% of their surfaces buried, on average, under more than 10 cm of sediment. In contrast, less than 5% of the meadow was affected at deeper locations. At three sites, we tracked short‐term mortality along a gradient of sediment burial. Survival response to burial was clearly nonlinear, with a significant threshold at 4-5 cm, beyond which shoot mortality was 100%. To track medium‐term potential recovery, we established permanent plots subject to three sediment burial levels (0-5, 5-10, and > 10 cm burial) in four meadows. Where the initial shoot mortality was 100%, we recorded no shoot recovery over the 4‐yr period. In the remaining plots, where some shoots remained alive, we detected either further mortality or shoot recovery of 7% per year on average. Extreme storm events can result in sudden catastrophic losses of seagrass cover in shallow P. oceanica meadows. In the long term and due to the long return time of such storms, the species may still be able to recover despite its low recovery potential. However, added anthropogenic stressors, including climate change, may seriously test the ability of long‐lived shallow seagrass ecosystems to resist high‐intensity natural disturbances and may be critical for its persistence