109 research outputs found

    A CHARACTERIZATION OF NETWORK PERFORMANCE: THE ROLE OF COMMUNICATION DIRECTIONALITY AND SYSTEM HETEROGENEITY

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    Networked dynamical systems’ ability to preserve the system equilibrium in the face of disruptive events or persistent disturbances can be an indication of the convergence efficiency and quantified as a measure of system performance. The performance analysis is usually facilitated by simplifications overlooking certain structural properties of the network that can potentially be significant to actual system behavior. We characterize the performance of networks in relation to these properties, such as communication directionality and system heterogeneity, and unravel their influence on overall performance. We examine performance metrics that quantify an aggregate system effort to maintain and/or restore a network equilibrium; formulated by a general quadratic function (L2 norm) of the system output. Using this approach, which builds on the widely-used H2 norm based analysis, we obtain novel closed-form solutions to the performance metrics. We then use them to identify the role of communication directionality and system heterogeneity in network performance. Particularly, we show that the effect of communication directionality on performance can be characterized by the spectral properties of the weighted Laplacian matrix describing the network interconnection and the output performance matrix. Our results indicate that while this directionality can degrade performance, well-designed feedback can also exploit directionality in certain cases to mitigate this degradation or even lead to improved performance. We also demonstrate that performance is sensitive to the degree of connectivity in networks with directed interconnection, however it does not necessarily improve by increasing this degree of connectivity. We then derive the asymptotic behavior of performance with respect to network size, and identify additional performance trade-offs associated with large-scale networks with communication directionality. In addition, we investigate system heterogeneity in droop-controlled inverter-based power systems, by relaxing the common assumption of uniformity of inverter control gains. This heterogeneity, which can result from the distribution of power demand between the inverters, can lead to performance limitations. Numerical examples verify and support our theoretical findings. Our results highlight the performance capabilities and limitations due to the structural properties of the network, and can inform judicious feedback design

    Clinical Use of Progesterone and Its Relation to Oxidative Stress in Ruminants

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    Studies to determine the physiological effects and functions of progesterone started in the twentieth century. Progesterone is a steroid-structured hormone with 21 carbon atoms originating from cholesterol. The corpus luteum, formed after ovulation in ruminants, secretes progesterone, which plays a role in the continuity of the pregnancy. Progestagens can be used for estrus synchronization in cows and heifers. Similarly, they are used for estrus synchronization during the breeding season or outside the breeding season by taking advantage of the negative feedback effect of progesterone in small ruminants. It is applied for the treatment of embryonic deaths due to luteal insufficiency in cows with high milk yield. In anovulatory anestrus, exogenous progesterone applications can be very useful. Progesterone treatment contributes to the resolution of the anestrus by rearranging hypothalamic functions in cattle with follicular cysts. The oxidative stress index in the luteal phase, when progesterone is high in ruminants, is higher than in the follicular phase. In the critical period of pregnancy, a high index of oxidative stress-induced progesterone causes embryonic death. Factors that cause stress in high milk-yielding cows can affect the amount of progesterone synthesis by inhibiting luteal cell function due to excessive free radical production

    A review of nature-based solutions for urban water management in European circular cities: a critical assessment based on case studies and literature

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    Nature-based solutions (NBS) can protect, manage and restore natural or modified ecosystems. They are a multidisciplinary, integrated approach to address societal challenges and some natural hazards effectively and adaptively, simultaneously providing human well-being and biodiversity benefits. NBS applications can be easily noticed in circular cities, establishing an urban system that is regenerative and accessible. This paper aims to offer a review on NBS for urban water management from the literature and some relevant projects running within the COST Action ‘Implementing nature-based solutions for creating a resourceful circular city’. The method used in the study is based on a detailed tracking of specific keywords in the literature using Google Scholar, ResearchGate, Academia.edu, ScienceDirect and Scopus. Based on this review, three main applications were identified: (i) flood and drought protection; (ii) the water-food-energy nexus; and (iii) water purification. The paper shows that NBS provide additional benefits, such as improving water quality, increasing biodiversity, obtaining social co-benefits, improving urban microclimate, and the reduction of energy consumption by improving indoor climate. The paper concludes that a systemic change to NBS should be given a higher priority and be preferred over conventional water infrastructure

    Holstein irkı bir İnekte karşılaşılan erken dönem fetal maserasyon olgusu

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    This case report describes a case of a cow shaped fetal maceration and operative results are presented in the early period. Undetected signs of vitality of the fetus by rectal examination, the uterus and vaginal examination, crepitus in the cervix with the uterus wall thickening were closed. Then, the cesarean operation was decided by operator. As a result, cases are reported in the literature have not completed the process of contrast, defined as a fetal maceration

    Effects of Debonding on Oral Mal odor

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    The objective of this study was to evaluate the affect of debonding on oral malodor. This study consists of three groups. The first group (debonding group) included 20 subjects with brackets and would be debonded in a month. The second group (bracket group) included 20 subjects who still undergone orthodontic treatment with brackets. The last group is a control group who did not receive orthodontic treatment. Oral malodor measurements, Gingival and Plaque Index scores were recorded in each group by same periodontist. Measurements were taken in first study groups before debonding (T1), 1 week after debonding (T2) and 4 weeks after bonding (T3). At the same time the measurements were applied to the second and control group. Data's were evaluated with three way ANOVA test. Bonferroni test were assessed when significant differences between the measurements were exist. Mann-Whitney U- test was used to compare both groups. Oral malodor, significantly decreased after debonding (P0.05). Control group did not show differences in all measurements. The comparison between groups showed significant differences between groups (P<0.05). Bonding brackets cause to increase on oral malodor. However, after debonding immediately oral malodor reached to the acceptable scores. Oral malodor could be another indicator to evaluate the oral health as Gingival and Plaque index scores

    Effects of the progesterone-based estrus synchronization on some reproductive parameters in abaza goats

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    Bu çalışmada, yerli keçi ırklarımızdan birisi olan Abaza keçilerinin ilk kez olarak progesteron kaynaklı senkronizasyon uygulamasının bazı reprodüktif özellikler ve döl verimi sonuçlarına etkilerinin araştırılması amaçlandı. Çalışmada 2-5 yaşlı, 40-50 kg ağırlığında 40 adet Abaza keçisi kullanıldı. Araştırma üreme mevsiminde gerçekleştirildi. Grup 1’e (n=15) kontrollü progesteron salan aparat (CIDR) ile hormon uygulaması yapılarak östrus senkronizasyonu sağlanırken, Grup 2‘ye ise (n=25) herhangi bir hormon uygulanmadı ve kontrol gurubu olarak değerlendirildi. Östrus süresi Grup 1 ve 2’de sırasıyla 25,1±2,11, 25,4±3,69 saat olarak belirlendi. İlk östrusta gebe kalma oranı Grup 1 ve 2 sırasıyla %73,33, %88 olarak saptandı. Gebelik süresi Grup 1 ve 2’de sırasıyla 153,50±3,21, 151,26±3,89 olarak belirlendi. Östrus süresi, ilk östrusta gebe kalma oranı, gebelik süresi, doğum saatleri arasında gruplar arasında istatistiksel bir fark gözlenmedi. Özellikle doğumların gündüz olduğu ve %72,98 oranında saat 06.00 ile 12.00 arasında görüldüğü saptandı (P<0,001). Çalışma süresince sadece 1 foliküler kist, 1 prematüre doğum ve 1 güç doğum olgusuyla karşılaşıldı. Grup 1'deki ikizlik oranının (%53,34) Grup 2'ye göre (%12) istatistiksel olarak önemli düzeyde yüksek olduğu belirlendi (P=0,005). Yirmi yedi keçide tek yavru (14 erkek - 13 dişi) doğumu izlenirken 10 keçide ikiz yavrulama (10 erkek - 10 dişi) gözlendi. Sonuç olarak, Abaza keçilerinin pek fazla reprodüktif sorun yaşamadığı, doğumlarının gündüz, ikiz doğumların az ve senkronizasyon uygulamalarının üretime herhangi bir olumsuz etkisinin olmadığı belirlendi.This study was undertaken to investigate the effects of progesterone-based synchronization on reproductive characteristics and fertility outcomes for the first time in native Abaza goat breed. A total of 40 Abaza goats, weighing 40-50 kg, aged 2-5 years, were used in the trial. The study was conducted during the mating season. Group 1 (n=15) received hormone administration with progesterone and estrus synchronization. Group 2 (n=25) did not receive hormone administration (control group). The length of estrus was 25.1±2.11 and 25.4±3.69 hours in Groups 1 and 2, respectively. The rate of pregnancy in the first estrus was 73.33% and 88% respectively in Group 1 and 2, respectively. Moreover, the duration of pregnancy was 153.50±3.21 and 151.26±3.89 Group 1 and 2 respectively. There was no statistically significant difference between the groups in terms of estrus duration, first estrous pregnancy rate, duration of pregnancy, and time of birth. It was especially found that the births were daytime and 72.98% between 06.00 and 12.00 hours (P<0.001). During the study, only 1 follicular cyst, 1 premature birth and 1 dystocia were encountered. Group 1 twin ratio (53.34%) was statistically significantly higher than Group 2 (12%) (P=0.005). The goats had 27 single (14 male - 13 female) and 10 twin (10 male - 10 female) births. As a result, it was determined that the Abaza goats did not have many reproductive problems, their births were daytime, the twin births were low and synchronization application has no negative effect on the production

    A Novel Label-Free Optical Biosensor Using Synthetic Oligonucleotides from E. coli O157:H7: Elementary Sensitivity Tests

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    SiO2-TiO2 thin films for use as fiber optic guiding layers of optical DNA biosensors were fabricated by the sol-gel dip coating technique. The chemical structure and the surface morphology of the films were characterized before immobilization. Single probe DNA strands were immobilized on the surface and the porosity of the films before the hybridization process was measured. Refractive index values of the films were measured using a Metricon 2010 prism coupler. On the surface of each film, 12 different spots were taken for measurement and calculation of the mean refractive index values with their standard deviations. The increased refractive index values after the immobilization of single DNA strands indicated that immobilization was successfully achieved. A further refractive index increase after the hybridization with target single DNA strands showed the possibility of detection of the E. coli O157:H7 EDL933 species using strands of 20-mers (5′-TAATATCGGTTGCGGAGGTG -3′) sequence

    A review of nature-based solutions for urban water management in European circular cities: a critical assessment based on case studies and literature

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    Abstract Nature-based solutions (NBS) can protect, manage and restore natural or modified ecosystems. They are a multidisciplinary, integrated approach to address societal challenges and some natural hazards effectively and adaptively, simultaneously providing human well-being and biodiversity benefits. NBS applications can be easily noticed in circular cities, establishing an urban system that is regenerative and accessible. This paper aims to offer a review on NBS for urban water management from the literature and some relevant projects running within the COST Action 'Implementing nature-based solutions for creating a resourceful circular city'. The method used in the study is based on a detailed tracking of specific keywords in the literature using Google Scholar, ResearchGate, Academia.edu, ScienceDirect and Scopus. Based on this review, three main applications were identified: (i) flood and drought protection; (ii) the water-food-energy nexus; and (iii) water purification. The paper shows that NBS provide additional benefits, such as improving water quality, increasing biodiversity, obtaining social co-benefits, improving urban microclimate, and the reduction of energy consumption by improving indoor climate. The paper concludes that a systemic change to NBS should be given a higher priority and be preferred over conventional water infrastructure

    Management of Urban Waters with Nature-Based Solutions in Circular Cities—Exemplified through Seven Urban Circularity Challenges

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    Nature-Based Solutions (NBS) have been proven to effectively mitigate and solve resource depletion and climate-related challenges in urban areas. The COST (Cooperation in Science and Technology) Action CA17133 entitled “Implementing nature-based solutions (NBS) for building a resourceful circular city” has established seven urban circularity challenges (UCC) that can be addressed effectively with NBS. This paper presents the outcomes of five elucidation workshops with more than 20 European experts from different backgrounds. These international workshops were used to examine the effectiveness of NBS to address UCC and foster NBS implementation towards circular urban water management. A major outcome was the identification of the two most relevant challenges for water resources in urban areas: ‘Restoring and maintaining the water cycle’ (UCC1) and ‘Water and waste treatment, recovery, and reuse’ (UCC2). s Moreover, significant synergies with ‘Nutrient recovery and reuse’, ‘Material recovery and reuse’, ‘Food and biomass production’, ‘Energy efficiency and recovery’, and ‘Building system recovery’ were identified. Additionally, the paper presents real-life case studies to demonstrate how different NBS and supporting units can contribute to the UCC. Finally, a case-based semi-quantitative assessment of the presented NBS was performed. Most notably, this paper identifies the most typically employed NBS that enable processes for UCC1 and UCC2. While current consensus is well established by experts in individual NBS, we presently highlight the potential to address UCC by combining different NBS and synergize enabling processes. This study presents a new paradigm and aims to enhance awareness on the ability of NBS to solve multiple urban circularity issues.publishedVersio

    Cytokine Gene Polymorphisms across Tuberculosis Clinical Spectrum in Pakistani Patients

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    BACKGROUND: Pakistan ranks 7(th) globally in terms of tuberculosis (TB) disease burden (incidence 181/100000 pop./yr; prevalence of 329/pop./yr). Reports from different populations show variable associations of TB susceptibility and severity with cytokine gene polymorphisms. Tuberculosis clinical severity is multi-factorial and cytokines play a pivotal role in the modulation of disease severity. We have recently reported that the ratio of two key cytokines (IFNgamma and IL10) show significant correlation with the severity spectrum of tuberculosis. The objective of the current study was to analyze the frequency of cytokine gene polymorphisms linked to high and low responder phenotypes (IFNgamma +874 T(hi)-->A(lo) and IL10 -1082 G(lo)-->A(hi)) in tuberculosis patients. METHODS AND FINDINGS: STUDY GROUPS WERE STRATIFIED ACCORDING TO DISEASE SITE AS WELL AS DISEASE SEVERITY: Pulmonary N = 111 (Minimal, PMN = 19; Moderate, PMD = 63; Advance, PAD = 29); Extra-pulmonary N = 67 (Disseminated DTB = 20, Localized LTB = 47) and compared with healthy controls (TBNA = 188). Genotype analyses were carried out using amplification refractory mutation system-PCR (ARMS-PCR) and stimulated whole blood (WB) culture assay was used for assessing cytokine profiles. Our results suggest that the IFNgamma +874 TT genotype and T allele was overrepresented in PMN (p = 0.01) and PMD (p = 0.02). IFNgamma +874 TT in combination with IL10 GG(lo) genotypes showed the highest association (chi(2) = 6.66, OR = 6.06, 95% CI = 1.31-28.07, p = 0.01). IFNgamma AA(lo) on the other hand in combination with IL10 GG(lo) increased the risk of PAD (OR = 5.26; p = 0.005) and DTB (OR = 3.59; p = 0.045). CONCLUSION: These findings are consistent with the role of IL10 in reducing collateral tissue damage and the protective role of IFNgamma in limiting disease in the lung
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