Inflammatory reaction in the retina after focal non-convulsive status epilepticus in mice investigated with high resolution magnetic resonance and diffusion tensor imaging

Pathophysiological consequences of focal non-convulsive status epilepticus (fNCSE) have been difficult to demonstrate in humans. In rats fNCSE pathology has been identified in the eyes. Here we evaluated the use of high-resolution 7 T structural T1-weighted magnetic resonance imaging (MRI) and 9.4 T diffusion tensor imaging (DTI) for detecting hippocampal fNCSE-induced retinal pathology ex vivo in mice. Seven weeks post-fNCSE, increased number of Iba1+ microglia were evident in the retina ipsilateral to the hemisphere with fNCSE, and morphologically more activated microglia were found in both ipsi- and contralateral retina compared to non-stimulated control mice. T1-weighted intensity measurements of the contralateral retina showed a minor increase within the outer nuclear and plexiform layers of the lateral retina. T1-weighted measurements were not performed in the ipsilateral retina due to technical difficulties. DTI fractional anisotropy(FA) values were discretely altered in the lateral part of the ipsilateral retina and unaltered in the contralateral retina. No changes were observed in the distal part of the optic nerve. The sensitivity of both imaging techniques for identifying larger retinal alteration was confirmed ex vivo in retinitis pigmentosa mice where a substantial neurodegeneration of the outer retinal layers is evident. With MR imaging a 50 % decrease in DTI FA values and significantly thinner retina in T1-weighted images were detected. We conclude that retinal pathology after fNCSE in mice is subtle and present bilaterally. High-resolution T1-weighted MRI and DTI independently did not detect the entire pathological retinal changes after fNCSE, but the combination of the two techniques indicated minor patchy structural changes

Pandemic vaccination strategies and influenza severe outcomes during the influenza A(H1N1)pdm09 pandemic and the post-pandemic influenza season: the Nordic experience.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadDuring the 2009/10 influenza A(H1N1)pdm09 pandemic, the five Nordic countries adopted different approaches to pandemic vaccination. We compared pandemic vaccination strategies and severe influenza outcomes, in seasons 2009/10 and 2010/11 in these countries with similar influenza surveillance systems. We calculated the cumulative pandemic vaccination coverage in 2009/10 and cumulative incidence rates of laboratory confirmed A(H1N1)pdm09 infections, intensive care unit (ICU) admissions and deaths in 2009/10 and 2010/11. We estimated incidence risk ratios (IRR) in a Poisson regression model to compare those indicators between Denmark and the other countries. The vaccination coverage was lower in Denmark (6.1%) compared with Finland (48.2%), Iceland (44.1%), Norway (41.3%) and Sweden (60.0%). In 2009/10 Denmark had a similar cumulative incidence of A(H1N1)pdm09 ICU admissions and deaths compared with the other countries. In 2010/11 Denmark had a significantly higher cumulative incidence of A(H1N1)pdm09 ICU admissions (IRR: 2.4; 95% confidence interval (CI): 1.9-3.0) and deaths (IRR: 8.3; 95% CI: 5.1-13.5). Compared with Denmark, the other countries had higher pandemic vaccination coverage and experienced less A(H1N1)pdm09-related severe outcomes in 2010/11. Pandemic vaccination may have had an impact on severe influenza outcomes in the post-pandemic season. Surveillance of severe outcomes may be used to compare the impact of influenza between seasons and support different vaccination strategies

RF-digitaali -muuntimet: Suora delta-sigma vastaanotin

The integration of electronics has been an ongoing process for a few decades. Ultimately, the goal is to include all of the needed electronics in a single integrated circuit (IC), also referred to as system on chip (SoC). The evolution towards SoC is driven by the multi-billion dollar industry around smartphones. New functionalities are added while the space reserved for electronics stays constant, or in the worst case, reduces. The circuits needed for communication are at the center point of this evolution, and with a good reason. A growing list of communication standards need to be supported, while guaranteeing backward compatibility to older standards. This results in multiple parallel radio hardware chains. Ideally, these chains would be replaced by a cognitive software defined radio (SDR), that is to say, a software reconfigurable radio that is able to adapt its operation in real-time based on the current spectrum usage. To accomplish this, the transmitter and receiver have to be highly programmable, which requires digital intensive implementations. Ultimately, the transmitter and receiver are comprised only of a digital-to-analog converter (DAC) or an analog-to-digital converter (ADC), in which case they can be referred to as digital-to-RF or RF-to-digital converters, respectively. The RF-to-digital converters are an intriguing approach to realize a cognitive SDR. Having an immediate analog-to-digital conversion after the antenna shifts the bulk of the signal processing to digital domain, which enables superior scalability and programmability over analog implementations. One promising RF-to-digital converter architecture is the direct delta-sigma receiver (DDSR), which combines a direct downconversion receiver and delta-sigma ADC. The DDSR embeds the receiver functional blocks into the delta-sigma loop-filter, and thus the digitalization of the analog input signal begins right after the antenna. The analog stages are used to their maximum potential as each stage participates in amplification, filtering and quantization noise shaping simultaneously, resulting in a compact design. The main challenge of the DDSR is that the RF frontend and the delta-sigma ADC can no longer be designed separately. Due to the increased design complexity, simple yet accurate models and design techniques are required to fully benefit from the DDSR. The objectives of this thesis are to 1) evaluate the feasibility of the DDSR as a future solution for integrated receiver, 2) provide a new perspective and understanding on the design of RF-to-digital converters, and 3) develop versatile models and design strategies that overcome the complexity of the DDSR.Elektroniikan integroimisprosessi on ollut käynnissä muutaman vuosikymmenen ajan. Tavoitteena on sisällyttää tarvittavat elektroniikan komponentit yhdelle integroidulle sirulle, jota kutsutaan järjestelmäksi sirulla. Järjestelmä sirulla -kehitystä on vienyt eteenpäin erityisesti miljardi-luokan älypuhelinteollisuus ja sen tarpeet. Uusia ominaisuuksia lisätään jatkuvasti mutta elektroniikalle varattu tila pysyy samana tai pahimmillaan pienenee. Kommunikaation tarvittava elektroniikka on tämän haasteen keskiössä ja hyvästä syystä. Lista tuettavista kommunikointistandardeista kasvaa, minkä lisäksi on taattava taaksepäin yhteensopivuus aikaisempien standardien kanssa, mikä vaatii tyypillisesti useita rinnakkaisia radiolaiteketjuja. Parhaimmassa tapauksessa nämä radiolaiteketjut voitaisiin korvata älykkäällä, ohjelmallisesti määritettävällä radiolla, joka pystyy mukauttamaan radioviestinnän käyttämiä taajuuksia vapaiden taajuusalueiden mukaan. Jotta tämä voidaan toteuttaa, tarvitaan digitaali-intensiivisiä, ohjelmoitavia lähettimiä ja vastaanottimia. Tavoitteena on, että lähettimet ja vastaanottimet muuntavat radiotaajuisen signaalin suoraan digitaalimuotoon, jolloin niitä voidaan kutsua digitaali-RF -muuntimiksi ja RF-digitaali -muuntimiksi, vastaavasti. RF-digitaali -muuntimet ovat kiehtova lähestymistapa älykkään, ohjelmallisesti määritettävän vastaanottimen toteuttamiseksi. Muuntamalla analoginen radiotaajuinen signaali mahdollisimman aikaisessa vaiheessa digitaaliseksi saavutetaan parempi skaalattavuus ja ohjelmoitavuus. Yksi lupaavista RF-digitaali -muunnin toteutuksista on suora delta-sigma vastaanotin, joka yhdistää suoramuunnosvastaanottimen ja delta-sigma analogia-digitaali -muuntimen. Suora delta-sigma vastaanottimessa sisällytetään suoramuunnosvastaanottimen toiminnot delta-sigma looppisuodattimeen, jolloin signaalin digitointi alkaa heti antennin jälkeen. Analogiset vahvistinasteet hyödynnetään maksimaalisesti, sillä jokainen aste osallistuu vahvitukseen, suodatukseen, antialiasointiin ja kvantisointikohinan muokkauseen samanaikaisesti, jonka tuloksena on kompakti kokonaisuus. Haasteeksi muodostuu se, että radiotaajuista etupäätä ja delta-sigma analogia-digitaali -muunninta ei voida enää suunnitella erikseen, joka johtaa monimutkaiseen suunnitteluvaiheeseen. Yksinkertaisia mutta samalla tarkkoja malleja ja suunnittelutekniikoita vaaditaan parhaan toimivuuden takaamiseksi. Tämän väitöskirjan tavoitteena on 1) evaluoida suora delta-sigma vastaanottimen soveltuvuutta tulevaisuuden vastaanottimeksi, 2) tuoda ymmärrystä ja uusi näkökulma RF-digitaali -muuntimien suunnitteluun, ja 3) kehittää käytännöllisiä malleja ja suunnittelustrategioita, jotka mahdollistavat monimutkaisuudesta ylitsepääsemisen

System and Baseband Design of a Direct Delta-Sigma Receiver for LTE

Monimuotoiset kommunikointistandardit, langattomien yhteyksien kasvaneet nopeudet ja pienenevät kommunikointilaitteet tuovat haasteita vastaanottimen suunnitteluun. Kehityksen suunta on kohti laajamittaista integrointia, joka soveltuu hyvin digitaalipainoitteisiin toteutuksiin. Analogisten lohkojen suorituskyky sen sijaan on hyvin riippuvainen analogisten komponenttien laadusta. Siksi on ymmärrettävää, että analogisten asteiden lukumäärä halutaan minimoida. Eräs ratkaisu tähän on delta-sigma -suoramuunnosvastaanotin, joka esiteltiin muutama vuosi sitten. Delta-sigma -suoramuunnosvastaanotin yhdistää suoramuunnosvastaanottimen, kanavasuodatuksen ja analogia-digitaali -muuntimen yhdeksi kokonaisuudeksi. Sen tuomien etujen mukana tulee myös haasteita. Esimerkiksi suunnittelu monimutkaistuu, kun eri lohkojen toiminnot yhdistetään. Tämä diplomityö, sekä siihen liittyvä kirjoittajan julkaisu, tähtäävät delta-sigma -suoramuunnosvastaanottimen suunnittelun havainnollistamiseen, sekä suunniteluprosessin nopeuttamiseen. Tämä diplomityö esittää neljännen asteen delta-sigma -suoramuunnosvastaanottimen suunnitteluprosessin ja kantataajuusosan toteutuksen. Yleinen kvantisointi- ja näytteenottoteoria käydään ensin läpi, minkä jälkeen kerrataan yleisesti tunnettu delta-sigma -muunninteoria. Kantataajuusosan vaatima suorituskyky määritellään LTE-standardin perusteella. Radiotaajuusosa on tämän diplomityön aiheen ulkopuolella ja sitä käsitellään vain tarpeen vaatiessa. Delta-sigma -suoramuunnosvastaanottimen suunnitteluvaiheet esitellään topologian valinnasta suotimen kertoimien optimointiin. Osittain ideaalisten piirisimulointien avulla määritellään olennaisimpien kantataajuusosan alilohkojen, kuten operaatiovahvistimen suorituskykyvaatimukset. Kantataajuuslohkot toteutetaan simulointien perusteella. Piirien toiminta varmistetaan simuloimalla.The multitude of different communication standards, increased wireless data speeds and ever smaller mobile communication devices present challenges to wireless receiver design. The trend is towards high level integration, which suits well for digital intensive implementations. However, the performance of the analog circuits relies heavily on the quality of analog components. Thus, there is a great interest in the reduction of the analog stages. One solution that minimizes the number of analog stages is the direct delta-sigma receiver, a receiver concept that was introduced recently. The direct delta-sigma receiver combines a direct conversion receiver, channel filtering and analog-to-digital conversion into one system. Although this offers certain benefits, the design process is more challenging as the functionalities are combined into one block. This thesis as well as the related publication by the author aims to illustrate and speed up the design of a direct delta-sigma receiver. This thesis presents the design process of a 4th-order direct delta-sigma receiver for LTE, and the implementation of the receiver baseband circuits. The basic concepts of quantization and sampling are reviewed first, after which general delta-sigma modulator theory is reviewed. The LTE standard is introduced shortly to obtain specifications for the receiver baseband. While the radio frequency front-end is out-of-scope of this thesis, the direct conversion receiver is reviewed as it is in a significant role in the direct delta-sigma receiver. The first steps of the direct delta-sigma design process, including topology selection and determining the optimal coefficients are presented. Partly ideal system level simulations are used to define specifications for the baseband circuits. Based on the specifications the schematics and layouts of the baseband circuits are implemented. Circuit and layout level simulations are used to confirm the performance

Plenary Discussion - Future of Collection Management Systems

The DINA Symposium ("DIgital information system for NAtural history data", https://dina-project.net) ends with a plenary session involving the audience to discuss the interplay of collection management and software tools. The discussion will touch different areas and issues such as: (1) Collection management using modern technology: How should and could collections be managed using current technology – What is the ultimate objective of using a new collection management system? How should traditional management processes be changed? (2) Development and community Why are there so many collection management systems? Why is it so difficult to create one system that fits everyone's requirements? How could the community of developers and collection staff be built around DINA project in the future? (3) Features and tools How to identify needs that are common to all collections? What are the new tools and technologies that could facilitate collection management? How could those tools be implemented as DINA compliant services? (4) Data What data must be captured about collections and specimens? What criteria need to be applied in order to distinguish essential and "nice-to-have" information? How should established data standards (e.g. Darwin Core & ABCD (Access to Biological Collection Data)) be used to share data from rich and diverse data models? In addition to the plenary discussion around these questions, we will agree on a streamlined format for continuing the discussion in order to write a white paper on these questions. The results and outcome of the session will constitute the basis of the paper and will be subsequently refined

Involving Collection Staff in the DINA Software Development – An Agile Approach

In order to ensure long-term commitment to the DINA project ("DIgital information system for NAtural history data", https://dina-project.net), it is essential to continuously deliver features of high value to the user community. This is also what agile software development methods try to achieve by emphasizing early delivery, rapid response to changes and close collaboration with users (see for example the Manifesto for Agile Software Development at http://agilemanifesto.org). We will give a brief overview on how current development of the DINA collection management system core is guided by agile principles. The mammal collection at the Swedish Museum of Natural History will be used as an example. Developing a cross-disciplinary collection management system is a complex task that poses many challenges: Which features should we focus on? What kinds of data should the system ultimately support? How can the system be flexible but still easy to use? Since we cannot do everything at once, we work towards a minimum viable product (MVP) that contains just enough features at a time to bring value for selected target users. In the mammal collection case, the MVP is the simplest product that is able to replace the functions of the current system used for managing the collection. As we begin to work with other collections, new MVPs are defined and used to guide further development. Thus, the set of features available will increase with each MVP, benefiting both new and current users. Another big challenge is migration of legacy data, which is labor intensive and involves standardizing data that are not compatible with the new system. To address these issues, we aim to build a flexible data model that allows less structured data to coexist with more complex, highly structured data. Migration should thus not require extensive data standardization, transformation and cleaning. The plan is to instead offer tools for transforming and cleaning the data after they have been imported. With the data in place, it will be easier for the user to provide feedback and suggest new features

A 0.35-to-2.6GHz multilevel outphasing transmitter with a digital interpolating phase modulator enabling up to 400MHz instantaneous bandwidth

Advanced wireless radio standards set stringent requirements on the bandwidth, frequency range and reconfigurability of base-station transmitters. Recently, the outphasing concept has shown promise of wide bandwidth while taking advantage of process scaling with extensive exploitation of rail-to-rail signaling. Recent outphasing transmitter designs have often focused on power-amplifier (PA) and power-combiner implementations while omitting the phase modulator [1,2]. Moreover, previously reported transmitters with integrated digital phase modulators have only shown bandwidths up to 40MHz [3,4], although 133MHz has been demonstrated at 10GHz carrier frequency utilizing phase modulators based on conventional IQ-DACs [5]. Thus, digital-intensive outphasing transmitters capable of modulation with hundreds of MHz bandwidth at existing cellular frequency bands have not yet been published. To address the aforementioned challenge, this paper introduces a multilevel outphasing transmitter with four amplitude levels, including the first prototype implementation based on the digital interpolating phase modulator concept [6]. The transmitter is targeted for 5G picocell base stations and has been verified to operate with instantaneous bandwidth up to 400MHz. In addition, the developed phase modulator eliminates the need for complex on-chip frequency synthesizers by introducing digital carrier frequency generation, demonstrated between 0.35 and 2.6GHz, while utilizing a single 1.8GHz reference clock.Peer reviewe

General introduction to DINA

The DINA Consortium (“DIgital information system for NAtural history data”, https://dina-project.net,Fig. 1 was formed in order to provide a framework for like-minded large natural history collection-holding institutions to collaborate through a distributed Open Source development model to produce a flexible and sustainable collection management system. Target collections include zoological, botanical, mycological, geological and paleontological collections, living collections, biodiversity inventories, observation records, and molecular data. The DINA system is architected as a loosely-coupled set of several web-based modules. The conceptual basis for this modular ecosystem is a compilation of comprehensive guidelines for Web application programming interfaces (APIs) to guarantee the interoperability of its components. Thus, all DINA components can be modified or even replaced by other components without crashing the rest of the system as long as they are DINA compliant. Furthermore, the modularity enables the institutions to host only the components they need. DINA focuses on an Open Source software philosophy and on community-driven open development, so the contributors share their development resources and expertise outside of their own institutions. One of the overarching reasons to develop a new collection management system is the need to better model complex relationships between collection objects (typically specimens) involving their derivatives, preparations and storage. We will discuss enhancements made in the DINA data model to better represent these relationships and the influence it has on the management of these objects, and on the sharing of information. Technical detail of various components of the DINA system will be shown in other talks in this symposium followed by a discussion session

Associations of human femoral condyle cartilage structure and composition with viscoelastic and constituent-specific material properties at different stages of osteoarthritis

The relationships between structure and function in human knee femoral cartilage are not well-known at different stages of osteoarthritis. Thus, our aim was to characterize the depth-dependent composition and structure (proteoglycan content, collagen network organization and collagen content) of normal and osteoarthritic human femoral condyle cartilage (n = 47) and relate them to their viscoelastic and constituent-specific mechanical properties that are obtained through dynamic sinusoidal testing and fibril-reinforced poroelastic material modeling of stress-relaxation testing, respectively. We characterized the proteoglycan content using digital densitometry, collagen network organization (orientation angle and anisotropy) using polarized light microscopy and collagen content using Fourier transform infrared spectroscopy. In the superficial cartilage (0–10 % of thickness), the collagen network disorganization and proteoglycan loss were associated with the smaller initial fibril network modulus - a parameter representing the pretension of the collagen network. Furthermore, the proteoglycan loss was associated with the greater strain-dependent fibril network modulus - a measure of nonlinear mechanical behavior. The proteoglycan loss was also associated with greater cartilage viscosity at a low loading frequency (0.005 Hz), while the collagen network disorganization was associated with greater cartilage viscosity at a high loading frequency (1 Hz). Our results suggest that proteoglycan loss and collagen network disorganization reduce the pretension of the collagen network while proteoglycan degradation also increases the nonlinear mechanical behavior of the collagen network. Further, the results also highlight that proteoglycan loss and collagen disorganization increase the viscosity of femoral cartilage, but their contribution to increased viscosity occurs in completely different loading frequencies