41 research outputs found

    Too close for comfort: spatial patterns in acorn barnacle populations

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    Spatial patterns in aggregations form as a result of the interplay between costs and benefits experienced by individuals. Such self-organisation of aggregations can be explained using a zonal model in which a short-range zone of repulsion and longer-range zone of attraction surrounding individuals leads to emergent pattern properties. The signal of these processes can be detected using spatial pattern analyses. Furthermore, in sessile organisms, post-settlement mortality reveals the relative costs and benefits of positions within the aggregation. Acorn barnacles are known to require contact with conspecifics for reproduction and are therefore believed to aggregate for this purpose; isolated individuals may also be more susceptible to abiotic stress and predation. At short distances, however, competition for space and resources is likely to occur. In this study spatial patterns of barnacles (Semibalanus balanoides L.) were analysed using pair-correlation functions. Individuals were dispersed at distances below 0.30 cm, but peak relative density occurred at a distance of 0.36 cm from conspecifics. This is much closer than required for reproductive access, implying a strong aggregative drive, up to the point of physical contact with neighbours. Nevertheless, analysis of dead barnacles illustrated that such proximity carries a cost as barnacles with many neighbours were more likely to have died. The inferences obtained from these patterns are that barnacles aggregate as closely as they can, and that local neighbourhood competition is a powerful determinant of mortality. These processes give rise to the observed pattern properties

    Diagnostic Accuracy of Age and Alarm Symptoms for Upper GI Malignancy in Patients with Dyspepsia in a GI Clinic: A 7-Year Cross-Sectional Study

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    <div><h3>Objectives</h3><p>We investigated whether using demographic characteristics and alarm symptoms can accurately predict cancer in patients with dyspepsia in Iran, where upper GI cancers and <em>H. pylori</em> infection are common.</p> <h3>Methods</h3><p>All consecutive patients referred to a tertiary gastroenterology clinic in Tehran, Iran, from 2002 to 2009 were invited to participate in this study. Each patient completed a standard questionnaire and underwent upper gastrointestinal endoscopy. Alarm symptoms included in the questionnaire were weight loss, dysphagia, GI bleeding, and persistent vomiting. We used logistic regression models to estimate the diagnostic value of each variable in combination with other ones, and to develop a risk-prediction model.</p> <h3>Results</h3><p>A total of 2,847 patients with dyspepsia participated in this study, of whom 87 (3.1%) had upper GI malignancy. Patients reporting at least one of the alarm symptoms constituted 66.7% of cancer patients compared to 38.9% in patients without cancer (p<0.001). Esophageal or gastric cancers in patients with dyspepsia was associated with older age, being male, and symptoms of weight loss and vomiting. Each single predictor had low sensitivity and specificity. Using a combination of age, alarm symptoms, and smoking, we built a risk-prediction model that distinguished between high-risk and low-risk individuals with an area under the ROC curve of 0.85 and acceptable calibration.</p> <h3>Conclusions</h3><p>None of the predictors demonstrated high diagnostic accuracy. While our risk-prediction model had reasonable accuracy, some cancer cases would have remained undiagnosed. Therefore, where available, low cost endoscopy may be preferable for dyspeptic older patient or those with history of weight loss.</p> </div

    CECT: computationally efficient congestion-avoidance and traffic engineering in software-defined cloud data centers

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    The proliferation of cloud data center applications and network function virtualization (NFV) boosts dynamic and QoS dependent traffic into the data centers network. Currently, lots of network routing protocols are requirement agnostic, while other QoS-aware protocols are computationally complex and inefficient for small flows. In this paper, a computationally efficient congestion avoidance scheme, called CECT, for software-defined cloud data centers is proposed. The proposed algorithm, CECT, not only minimizes network congestion but also reallocates the resources based on the flow requirements. To this end, we use a routing architecture to reconfigure the network resources triggered by two events: (1) the elapsing of a predefined time interval, or, (2) the occurrence of congestion. Moreover, a forwarding table entries compression technique is used to reduce the computational complexity of CECT. In this way, we mathematically formulate an optimization problem and define a genetic algorithm to solve the proposed optimization problem. We test the proposed algorithm on real-world network traffic. Our results show that CECT is computationally fast and the solution is feasible in all cases. In order to evaluate our algorithm in term of throughput, CECT is compared with ECMP (where the shortest path algorithm is used as the cost function). Simulation results confirm that the throughput obtained by running CECT is improved up to 3× compared to ECMP while packet loss is decreased up to 2×

    Investigation of Genetic Diversity of Wilsonomyces carpophilus in Khorasan Razavi Using rep-PCR Marker

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    Introduction: Shot hole disease of stone fruit trees resulted from Wilsonomyces carpophilus can weaken the trees and reduce the quantity and quality of the crops worldwide particularly in semi-arid regions. Coryneum blight or shot hole disease infects all the stone fruit trees including peach, nectarine, apricot, sour cherry, plum, cherry, and almond. One of the most important strategies to manage any plant disease is to use resistant cultivars. In this way, it is very important to have knowledge about the status of genetic diversity and to determine the relationship between isolates of the causal agent fungus. The main objective of the present research was to study the genetic diversity of W. carpophilus in Khorasan Razavi province using the rep-PCR molecular fingerprinting method. Materials and Methods: Sampling was performed from peach, nectarine, plum, apricot and cherry orchards of Quchan, Torqabeh, Shandiz, Chenaran, Neishabur, Kalat, Torbat Heidarieh and Mashhad during spring and summer of 2012 and 2013. Mono-conidial isolates were recovered from infected leaves, fruits, and twigs of different parts of orchards. Infected collected leaves, twigs, and fruits were transferred to the laboratory. By using techniques of Klimesova and Prasil (1989) and Mehta (1998) from the cut parts between infected and healthy tissues of each isolate, cuts of 2-3 mm from leaf, fruit and twig were prepared by the scalpel. These pieces were surface sterilized with 1% sodium hypochlorite liquid about 1 to 3 minutes based on the thickness of tissue. Then, the samples were cultured on PDA, MEA, and WA media and incubated at 18, 20, and 25 °C. The isolated fungi were purified and identified. The research was performed on 20 fungal isolates collected from different stone fruit trees. Genomic DNA was amplified using BOX A1R, ERIC2, ERIC1R, REP2-I, and REP1R-I primers. Thirty-eight of 39 fragments amplified were polymorphic for 100 to 5000 base pairs. Similarity matrix between isolates was calculated based on Jacquard Coefficient and cluster analysis and construction of dendrogram were done based on UPGM using NTYSIS.PC 2.0 software. Results and discussion: From 39 amplified bands, 38 bands (97.5%) showed polymorphism. The molecular weight of amplified DNA fragments was between 100 to 5000 bp. Based on analysis of banding pattern of REP primer set, isolates of W. carpophilus were categorized into 12 groups at the 69% similarity level. The most genetic similarity of isolates (94%) was between AK (apricot of Kalat) and PK (peach of Kalat) and the least genetic similarity of W. carpophilus isolates was between AQ (apricot of Quchan), AN (apricot of Neishabur), AC (apricot of Chenaran), PlM (plum of Mashhad), PM2 (peach of Mashhad number 2), and CC (cherry of Chenaran) with the other isolates. Based on the results of this study rep-PCR could separate isolates of W. carpophilus very well and also could separate similar isolates and hosts which have the close genetic relationship. Similar results were obtained by Edel et al. (1995) and Jedryczka et al. (1999). Edel et al. (1995) compared three different molecular methods for characterization of Fusarium oxysporum strains. The marker also separated isolates of Kalat and Chenaran geographically and to some extent isolates of plum in terms of hosting from the other isolates. Toda et al. (1999) in their study, about the investigation of genetic correlation among and within different isolates of Rhizoctonia solani by rep-PCR divided the 41 isolates into 7 groups which indicate considerable genetic diversity among isolates. Also, Karimi et al. (2010) in their study about the investigation of genetic diversity of Sclerotinia sclerotiorum at 64% similarity level, divided the isolates into 7 groups and separated most of the isolates geographically. Conclusion: The results obtained in this study indicated that rep-PCR is a practical, rapid, and accurate technique for separation of W. carpophilus isolates. Considering the high genetic diversity observed in the population of this fungus, making attempts to plant cultivars with high resistance and resistant genes can largely prevent the outbreaks and intensity of the pathogen. Therefore, further researches in this area can be placed in breeding, production and reproduction of cultivars with particular resistance programs against shot hole disease. The present research study is a prelude to solving problems related to this important disease

    Novel quinazolin-4(3H)-one linked to 1,2,3-triazoles: Synthesis and anticancer activity

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    In this work, a wide range of novel quinazolin-4(3H)-one linked to 1,2,3-triazoles was designed, synthesized, and evaluated against a panel of three human breast (MDA-MB-231, MCF-7, T-47D), lung (A549), and prostate (PC3) cancer cell lines. Our results revealed that the anticancer activity of the synthesized compounds was selectively affected by the presence of methoxy group on the linker between quinazolinone and 1,2,3-triazole moieties. According to the calculated IC50 values, compounds 6q, 6w, and 6x showed good cytotoxicity against breast cancer cell lines even more effective than the reference drug, etoposide. Compounds 6q and 6u were found to be potent compounds against A549, non-small-cell lung cancer (NSCLC), comparing with erlotinib. Also, the morphological analysis by acridine orange/ethidium bromide double staining test and flow cytometry analysis indicated that potent compounds induced apoptosis in human cancer cell lines. Molecular docking studies were performed to clarify the inhibition mode of compounds 6g, 6u, 6w, and 6x over the EGFR active site. The most promising compounds, 6q and 6u, possessing 3-methoxy group were well oriented to the gatekeeper hydrophobic pocket of EGFR active site and interact well with Ala719, Val702, and Leu820 through hydrophobic interaction. © 2018 John Wiley & Sons A/S

    The Association of Consumption of Animal Proteins and the Risk of Esophageal Cancer

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    Aim: Esophageal cancer (EC) is considered one of the most common types of cancer in the world. High intake of dietary proteins is suggested to increase EC. This study examined associations between intake of red meats, processed meat, poultry, and fish and the risk of EC. Methods: This hospital-based Case–Control study included 96 people with EC and 187 people without EC from Bojnurd, Iran. Socio-demographic data was collected from all participants at enrollment using general information questionnaire. Dietary intake was assessed using a validated 168 item semi-quantitative food frequency questionnaire. Results: After adjusting for potential confounders, there was a significant association between the consumption of beef (P = 0.04), processed meats (sausages) (P = 0.01), and chicken with skin (P = 0.001) with the risk of EC. Conclusion: We observed a positive association between red meat, processed meats (sausages), chicken with skin and the risk of EC. The use of lamb meat and fish had no significant association with the risk of E

    CECT: Computationally Efficient Congestion-avoidance and Traffic Engineering in Software-defined Cloud Data Centers

    No full text
    The proliferation of cloud data center applications and network functionvirtualization (NFV) boosts dynamic and QoS dependent traffic into the datacenters network. Currently, lots of network routing protocols are requirementagnostic, while other QoS-aware protocols are computationally complex andinefficient for small flows. In this paper, a computationally efficientcongestion avoidance scheme, called CECT, for software-defined cloud datacenters is proposed. The proposed algorithm, CECT, not only minimizes networkcongestion but also reallocates the resources based on the flow requirements.To this end, we use a routing architecture to reconfigure the network resourcestriggered by two events: 1) the elapsing of a predefined time interval, or, 2)the occurrence of congestion. Moreover, a forwarding table entries compressiontechnique is used to reduce the computational complexity of CECT. In this way,we mathematically formulate an optimization problem and define a geneticalgorithm to solve the proposed optimization problem. We test the proposedalgorithm on real-world network traffic. Our results show that CECT iscomputationally fast and the solution is feasible in all cases. In order toevaluate our algorithm in term of throughput, CECT is compared with ECMP (wherethe shortest path algorithm is used as the cost function). Simulation resultsconfirm that the throughput obtained by running CECT is improved up to 3xcompared to ECMP while packet loss is decreased up to 2x
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