| 1. |
- Abu-Humaidan, Anas Haider
(författare)
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Rules of engagement - Regulation of complement response in tissue
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Always in motion and probing for danger, complement proteins are found in every space and notch of the body. Their omnipresence combined with an ability to wreak havoc when activated, mandates a strong leash! The how, when, and where to unleash or constrain the complement response remain partly answered questions, despite the significant progress made in the field in the past 100 years.The work in this thesis aims to answer some of these questions with models that compare healthy and disease states, using methods that investigate complement response in each. The investigation often followed the lines ofqueries like: Is complement relevant to this disease state? Is complement activated or its expression induced? If so, through what mechanisms? And what local effect could the activation or induced expression have?Chapter 1 provides an introduction to the complement system that tackles specific topics like complement’s discovery, evolution, function and role in disease. As well as challenges and progress made in complement targeted therapies. Chapter 2 discusses methods and models used in this thesis and in complement research in general. While chapter 3 focuses on the present investigation and where it falls within current knowledge about the local regulation of complement.
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| 2. |
- Agarwal, Vaibhav, et al.
(författare)
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A novel interaction between complement inhibitor C4b-binding protein and plasminogen that enhances plasminogen activation.
- 2015
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 290:30, s. 18333-18342
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Tidskriftsartikel (refereegranskat)abstract
- The complement, coagulation and fibrinolytic systems are crucial for the maintenance of tissue homeostasis. To date numerous interactions and cross talks have been identified between these cascades. In line with this, here we propose a novel, hitherto unknown interaction between the complement inhibitor C4b-binding protein (C4BP) and plasminogen of the fibrinolytic pathway. Binding of C4BP to S. pneumoniae is a known virulence mechanism of this pathogen and it was increased in the presence of plasminogen. Interestingly, the acute phase variant of C4BP lacking the β-chain and protein S binds plasminogen much stronger than the main isoform containing the β-chain and protein S. Indeed, the complement control protein (CCP) 8 domain of C4BP, which would otherwise be sterically hindered by the β-chain, primarily mediates this interaction. Moreover, the lysine-binding sites in plasminogen kringle domains facilitate the C4BP-plasminogen interaction. Furthermore, C4BP readily forms complexes with plasminogen in fluid phase and such complexes are present in human serum and plasma. Importantly, while the presence of plasminogen did not affect the factor I cofactor activity of C4BP, the activation of plasminogen by urokinase-type plasminogen activator to active plasmin was significantly augmented in the presence of C4BP. Taken together, our data demonstrate a novel interaction between two proteins of the complement and fibrinolytic system. Most complexes might be formed during the acute phase of inflammation and have an effect on the homeostasis at the site of injury or acute inflammation.
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| 3. |
- Agarwal, Vaibhav, et al.
(författare)
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Binding of Streptococcus pneumoniae endopeptidase O (PepO) to complement component C1q modulates the complement attack and promotes host cell adherence.
- 2014
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 289:22, s. 15833-15844
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Tidskriftsartikel (refereegranskat)abstract
- The Gram-positive species Streptococcus pneumoniae is a human pathogen causing severe local and life-threatening invasive diseases associated with high mortality rates and death. We demonstrated recently that pneumococcal endopeptidase O (PepO) is an ubiquitously expressed, multifunctional plasminogen and fibronectin binding protein facilitating host cell invasion and evasion of innate immunity. In this study we found that PepO interacts directly with the complement C1q protein, thereby attenuating the classical complement pathway and facilitating pneumococcal complement escape. PepO binds both free C1q and C1 complex in a dose-dependent manner based on ionic interactions. Our results indicate that recombinant PepO specifically inhibits the classical pathway of complement activation in both hemolytic and complement deposition assays. This inhibition is due to direct interaction of PepO with C1q, leading to a strong activation of the classical complement pathway and results in consumption of complement components. In addition, PepO binds the classical complement pathway inhibitor C4BP, thereby regulating downstream complement activation. Importantly, pneumococcal surface-exposed PepO-C1q interaction mediates bacterial adherence to host epithelial cells. Taken together, PepO facilitates C1q-mediated bacterial adherence, while its localized release consumes complement as a result of its activation following binding of C1q, thus representing an additional mechanism of human complement escape by this versatile pathogen.
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| 4. |
- Amara, Sofiane, et al.
(författare)
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Using fouggara for heating and cooling buildings in Sahara
- 2011
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 6, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- In order to utilise naturally stored heat or cold from the ground, seasonal temperature variations are required. The reason is that the ground temperature is then warmer than the air temperature during winter and colder during summer. The heating and cooling demand in North Africa varies considerably with the greatest cooling demand in the East and the greatest heating demand in the West. In parts of Algeria the mean temperature difference between the coldest and warmest month is greater than 20 °C, which is favourable. In current work it was shown that the ancient Fouggara system, even today would be interesting for heating and cooling of buildings in the Sahara desert.
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| 5. |
- Ansari, Muhammad Adeel
(författare)
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TDMA for Low Sampling Rate IR-UWB Receivers
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In UWB communication sampling plays a key role in detection of the transmitted data. There are various methods of data transmission and detection at the receiver. Mostly, the detection methods are based on frequency domain methods. The popular method to lower the sampling rate is the sub-sampling technique, based on frequency of the transmitted signal. A special method like orthogonal frequency division multiplexing (OFDM) is needed to reduce inter symbol interference for a frequency based method. The power consumption associated with higher sampling rates is also a big challenge. Therefore some simple techniques are required to detect data on lower sampling rates without ISI in the multiple user environments and with lower power consumption. If selection of the sampling frequency would be flexible to detect data from multiple users then it could relax the UWB receiver design requirements. In this thesis we developed a transmission and reception methodology with reduced sampling frequency for data detection. In the proposed work, transmitted data is distributed using TDMA frames for all users within fixed time slots for each user. The TDMA technique is being used to achieve low sampling rates and to avoid multiple access interference (MAI). The sampling rate to detect the data of each user can be selected according to number of users and transmission bandwidth. For this purpose each data bit of a user is arranged once in a transmission frame. The data can be detected on frame repetition rate depends on the total number of users. The data of each user can be accessed directly by calculating the total time of each user place within each frame. Since each data bit of one user occurs once in a frame therefore it could be claimed that ISI within the same user has been avoided. The proposed scheme has been tested with 50 MHz, 100 MHz and 500 MHz sampling frequencies for 50 users, 25 users and 5 users respectively by using 2.5 GHz bandwidth. 8-bits of data was transmitted and detected for different users using Matlab and Simulink Models. The results were analyzed in perfect synchronization condition and compared between integrated window energy detector UWB receiver and an UWB receiver using a matched filter. The performances are evaluated on the basis of BER. To observe the impact of synchronization, both receivers were evaluated with some timing mismatch. It is concluded that the scheme works well for the lower sampling rate for both types of UWB receivers stated above. It can also be concluded by observing the results that the UWB receiver using matched filter has better performance in noisy environment compared to energy detector UWB receiver with integrated window. The performance of energy detector UWB receiver with integrated window and UWB receiver with matched filter were also evaluated with timing mismatch. It can be concluded that the UWB receiver with integrated window has better performance compared to UWB receiver using matched filter if the synchronization is not achieved properly. The UWB receiver with matched filter is more vulnerable against timing mismatch compared to UWB receiver with integrated window.
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| 6. |
- Aviles, Marcos, et al.
(författare)
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A co-design methodology for implementing computer vision algorithms for rover navigation onto reconfigurable hardware
- 2011
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Ingår i: Proceedings of the FPL2011 Workshop on Computer Vision on Low-Power Reconfigurable Architectures. ; , s. 9-10
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Vision-based robotics applications have been widely studied in the last years. However, up to now solutions that have been proposed were affecting mostly software level. The SPARTAN project focuses in the tight and optimal implementation of computer vision algorithms targeting to rover navigation. For evaluation purposes, these algorithms will be implemented with a co-design methodology onto a Virtex-6 FPGA device.
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| 7. |
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| 8. |
- Balčytienė, Auksė, et al.
(författare)
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Lithuania : Media-politics interaction shaped by benefits-oriented reasoning
- 2019
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Ingår i: Close and Distant. - Gothenburg : Nordicom, University of Gothenburg. - 9789188855060 - 9789188855077 ; , s. 55-74
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter discusses how media and political information sources navigate change and adjust their needs-oriented behaviour to changing conditions. The results presented are based on 20 qualitative interviews with leading political journalists as well as government advisors and spokespersons in Lithuania. Although media and political sources gain power in different situations, both sides function in reciprocal interconnectedness. Formal contacts are quite consistent and professionalised, but they continue to work in the shadow of informal social networks, which create their own power relationships, dynamics and hierarchical structures. Though the findings are contextually fashioned, the views regarding the interaction indicate broader trends of communication professionalisation identified also in other cultures and political conditions.
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| 9. |
- Baptista La, Filipa Martins, et al.
(författare)
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Pregnancy and the Singing Voice : Reports From a Case Study
- 2012
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 26:4, s. 431-439
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Significant changes in body tissues occur during pregnancy; however, literature concerning the effects of pregnancy on the voice is sparse, especially concerning the professional classically trained voice. Hypotheses. Hormonal variations and associated bodily changes during pregnancy affect phonatory conditions, such as vocal fold motility and glottal adduction. Design. Longitudinal case study with a semiprofessional classically trained singer. Methods. Audio, electrolaryngograph, oral pressure, and air flow signals were recorded once a week during the last 12 weeks of pregnancy, 48 hours after birth and during the following consecutive 11 weeks. Vocal tasks included diminuendo sequences of the syllable /pae/sung at various pitches, and performing a Lied. Phonation threshold pressures (PTPs) and collision threshold pressures (CTPs), normalized amplitude quotient (NAQ), alpha ratio, and the dominance of the voice source fundamental were determined. Concentrations of sex female steroid hormones were measured on three occasions. A listening test of timbral brightness and vocal fatigue was carried out. Results. Results demonstrated significantly elevated concentrations of estrogen and progesterone during pregnancy, which were considerably reduced after birth. During pregnancy, CTPs and PTPs were high; and NAQ, alpha ratio, and dominance of the voice source fundamental suggested elevated glottal adduction. In addition, a perceptible decrease of vocal brightness was noted. Conclusions. The elevated CTPs and PTPs during pregnancy suggest reduced vocal fold motility and increased glottal adduction. These changes are compatible with expected effects of elevated concentrations of estrogen and progesterone on tissue viscosity and water retention.
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