An Analytical Approach to Neuronal Connectivity

This paper describes how realistic neuromorphic networks can have their connectivity properties fully characterized in analytical fashion. By assuming that all neurons have the same shape and are regularly distributed along the two-dimensional orthogonal lattice with parameter $\Delta$, it is possible to obtain the accurate number of connections and cycles of any length from the autoconvolution function as well as from the respective spectral density derived from the adjacency matrix. It is shown that neuronal shape plays an important role in defining the spatial spread of network connections. In addition, most such networks are characterized by the interesting phenomenon where the connections are progressively shifted along the spatial domain where the network is embedded. It is also shown that the number of cycles follows a power law with their respective length. Morphological measurements for characterization of the spatial distribution of connections, including the adjacency matrix spectral density and the lacunarity of the connections, are suggested. The potential of the proposed approach is illustrated with respect to digital images of real neuronal cells.Comment: 4 pages, 6 figure

Moat: A Virtual Private Network Appliance and Services Platform

Vakava onnettomuus, sairaus tai aivoinfarkti voi aiheuttaa tilan, jossa ihminen ei pysty liikkumaan eikä puhumaan. Usein kyky liikuttaa silmiä kuitenkin säilyy, vaikka ihminen olisi muuten täysin halvaantunut. Silmien liikettä ja katseen suuntaa voidaan tällöin hyödyntää kommunikaatiossa. Lääkäri voi esimerkiksi pyytää potilasta katsomaan ylös myöntymisen merkiksi. Vammautuneen henkilön eteen voidaan myös asettaa läpinäkyvä kommunikaatiotaulu, johon on kiinnitetty kuvia tai kirjaimia. Taulun avulla on mahdollista muodostaa sanoja ja lauseita katsomalla kirjaimia yksi kerrallaan. Keskustelukumppani tulkitsee viestin seuraamalla kommunikaatiotaulun toiselta puolelta henkilön katseen suuntaa. Kommunikaatiotaulua kehittyneempi menetelmä on katseenseurantalaite, joka mahdollistaa itsenäisen kirjoittamisen ja tietokoneen ohjaamisen katseella. Katseenseurantalaitteessa on tyypillisesti videokamera, joka kuvaa käyttäjän silmän liikkeitä. Tietokoneen ohjelma tulkitsee katseen suunnan ja päättelee, mihin kohtaan näytöllä käyttäjä kulloinkin katsoo. Yksinkertaisimmillaan näytöllä on kuva näppäimistöstä ja käyttäjä kirjoittaa silmillään katsomalla näppäimistön kirjaimia. Jotta tietokone erottaisi, milloin käyttäjä haluaa valita katsomansa kohteen, käyttäjän pitää katsoa kirjainta riittävän pitkään. Pitkä viive auttaa ehkäisemään virhevalintoja, mutta hidastaa samalla kommunikaatiota. Katseeseen perustuvia tekstinsyöttöjärjestelmiä on kehitetty muutaman vuosikymmenen ajan ja niiden käyttö kommunikaation apuvälineenä on yleistynyt viime vuosina. Katseella kirjoittamista ei kuitenkaan ole juurikaan tutkittu. Väitöskirja tarjoaa perusteellisen katsauksen aiheen tutkimukseen ja eri tapoihin käyttää katsetta tekstin tuottamiseen ja kommunikointiin. Työssä esitellään uusia tapoja tehostaa katseella kirjoittamista yksinkertaisten käyttöliittymäratkaisujen avulla. Väitöskirja tarjoaa tutkimustuloksiin perustuvia konkreettisia esimerkkejä ja ohjeita siitä, kuinka katseella kirjoittamisen miellyttävyyttä ja nopeutta voidaan parantaa huolellisen käyttöliittymäsuunnittelun avulla. Käyttäjätutkimukset osoittavat, että esimerkiksi ohjelman tarjoama palaute vaikuttaa merkittävästi kirjoitusnopeuteen ja virheiden määrään. Vastaavasti mahdollisuus säätää valintaan vaadittavaa viivettä mahdollistaa katsekirjoituksen nopean ja tehokkaan oppimisen.Text entry by eye gaze is used by people with severe motor disabilities. An eye tracking device follows the user s eye movements, and a computer program analyzes the gaze behavior. To type by gaze, the user typically points at the characters on an on-screen keyboard by looking at them and selects them by means of dwell time, a prolonged gaze that separates an intentional command from casual viewing. The basic methods for producing text by gaze have been researched and in real-world use since the early 1980s; however, the design issues have not been studied in detail. Until recently, assistive eye tracking systems were used mostly by a small number of people who were totally paralyzed and for whom gaze control was a necessity and the only option. The technology and its usability have improved considerably, and several new systems have appeared on the market, making the technology available for a much wider group of users with varying need and abilities. Today, the eye tracker can be considered an optional assistive device worth considering since it provides easy and fast access to information technology by gaze alone. This thesis provides an extensive review of the research conducted in the area of gaze-based text entry. It summarizes results from several experiments that study various aspects of text entry by gaze. Results show that small improvements in the interface design can lead to significant improvements in user performance and satisfaction. For example, adding a simple "click" that confirms the selection by gaze can significantly improve the text entry speed over that of plain visual feedback. The improvement is small, but the effect accumulates in the repetitive task of text entry. An overview of different design solutions and guidelines derived from the research results are given. It is hoped that the thesis will provide a useful starting point for developers, researchers, and assistive technology professionals wishing to gain deeper insight into gaze-based text entry

Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record

Medvedev and Melott (2007) have suggested that periodicity in fossil biodiversity may be induced by cosmic rays which vary as the Solar System oscillates normal to the galactic disk. We re-examine the evidence for a 62 million year (Myr) periodicity in biodiversity throughout the Phanerozoic history of animal life reported by Rohde & Mueller (2005), as well as related questions of periodicity in origination and extinction. We find that the signal is robust against variations in methods of analysis, and is based on fluctuations in the Paleozoic and a substantial part of the Mesozoic. Examination of origination and extinction is somewhat ambiguous, with results depending upon procedure. Origination and extinction intensity as defined by RM may be affected by an artifact at 27 Myr in the duration of stratigraphic intervals. Nevertheless, when a procedure free of this artifact is implemented, the 27 Myr periodicity appears in origination, suggesting that the artifact may ultimately be based on a signal in the data. A 62 Myr feature appears in extinction, when this same procedure is used. We conclude that evidence for a periodicity at 62 Myr is robust, and evidence for periodicity at approximately 27 Myr is also present, albeit more ambiguous.Comment: Minor modifications to reflect final published versio

How the Internet of Things Technology Enhances Emergency Response Operations

The Internet of Things (IoT) is a novel paradigmthat connects the pervasive presence around us of a variety of things or objects to the Internet by using wireless/wired technologies to reach desired goals. Since the concept of the IoT was introduced in 2005, we see the deployment of a new generation of networked smart objects with communication, sensory and action capabilities for numerous applications, mainly in global supply chain management, environment monitoring and other non-stress environments. This paper introduces the IoT technology for use in the emergency management community. Considering the information required for supporting three sequential and distinct rhythms in emergency response operations: mobilization rhythm, preliminary situation assessment rhythm, and intervention rhythm, the paper proposes a modified task-technology fit approach that is used to investigate how the IoT technology can be incorporated into the three rhythms and enhance emergency response operations. The findings from our research support our two hypotheses: H1: IoT technology fits the identified information requirements; and H2: IoT technology provides added value to emergency response operations in terms of obtaining efficient cooperation, accurate situational awareness, and complete visibility of resources

How the internet of things technology enhances emergency response operations

The Internet of Things (IoT) is a novel paradigm that connects the pervasive presence around us of a variety of things or objects to the Internet by using wireless/wired technologies to reach desired goals. Since the concept of the IoT was introduced in 2005, we see the deployment of a new generation of networked smart objects with communication, sensory and action capabilities for numerous applications, mainly in global supply chain management, environment monitoring and other non-stress environments. This paper introduces the IoT technology for use in the emergency management community. Considering the information required for supporting three sequential and distinct rhythms in emergency response operations: mobilization rhythm, preliminary situation assessment rhythm, and intervention rhythm, the paper proposes a modified task-technology fit approach that is used to investigate how the IoT technology can be incorporated into the three rhythms and enhance emergency response operations. The findings from our research support our two hypotheses: H1: IoT technology fits the identified information requirements; and H2: IoT technology provides added value to emergency response operations in terms of obtaining efficient cooperation, accurate situational awareness, and complete visibility of resources. © 2012 Elsevier Inc

Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein

Citation: Londono-Renteria, B., Troupin, A., Conway, M. J., Vesely, D., Ledizet, M., Roundy, C. M., . . . Colpitts, T. M. (2015). Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein. Plos Pathogens, 11(10), 23. doi:10.1371/journal.ppat.1005202Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were >= 5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379), whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses

Safety and effectiveness of insulin pump therapy in children and adolescents with type 1 diabetes

WSTĘP. Celem pracy była ocena bezpieczeństwa skuteczności stosowania pompy insulinowej u dzieci młodzieży chorych na cukrzycę typu 1. MATERIAŁ I METODY. Do badania włączono 95 dzieci, które rozpoczęły stosowanie pompy insulinowej w Johns Hopkins Hospital w okresie od stycznia 1990 do grudnia 2000 roku. Średni wiek badanych wynosił 12,0 lat (przedział 4&#8211;18 lat); 29% badanych było poniżej 10 roku życia. Dane zebrano z dokumentacji medycznej, począwszy od okresu 6&#8211;12 miesięcy przed zastosowaniem terapii pompą insulinową. Średni czas obserwacji wynosił 28 miesięcy. WYNIKI. Zaobserwowano niewielkie, lecz znamienne statystycznie obniżenie stężenia HbA1c w 3.&#8211;6. miesiącu terapii (7,7% vs. 7,5%, p = 0,03). W czasie dalszej obserwacji stężenie to stopniowo zwiększało się i pozostało podwyższone po roku, jednak na to zjawisko wpływał wiek badanych i czas trwania cukrzycy. Obie wymienione zmienne wiązały się z wyższym stężeniem HbA1c. Po uwzględnieniu wieku i czasu trwania cukrzycy średnie stężenie HbA1c po rozpoczęciu terapii pompą insulinową było znamiennie niższe niż przed jej zastosowaniem (7,7% vs. 8,1%, p < 0,001). Częstość powikłań (kwasica ketonowa, interwencje w izbie przyjęć) była podobna przed i po rozpoczęciu leczenia. Zaobserwowano mniej incydentów hipoglikemii po rozpoczęciu terapii (12 vs. 17, współczynnik częstości = 0,46; 95% CI 0,21&#8211;1,01). WNIOSKI. Badanie to sugeruje, że stosowanie pompy insulinowej jest bezpieczną i skuteczną metodą leczenia u wybranych dzieci chorych na cukrzycę typu 1.INTRODUCTION. To evaluate the safety and effectiveness of insulin pump therapy in children and adolescents with type 1 diabetes. MATERIAL AND METHODS. All 95 patients who began insulin pump therapy at Johns Hopkins Hospital between January 1990 and December 2000 were included in the study. The mean age was 12.0 years (range 4&#8211;18), and 29% of the patients were < 10 years old. Data were obtained by chart review beginning 6&#8211;12 months before pump start. The median duration of follow-up was 28 months. RESULTS. There was a small but significant decrease in HbA1c at 3&#8211;6 months after pump start (7.7% vs. 7.5%; P = 0.03). HbA1c levels then gradually increased and remained elevated after 1 year of followup; however, this association was confounded by age and diabetes duration, both of which were associated with higher HbA1c levels. After adjusting for duration and age, mean HbA1c after pump start was significantly lower than before pump start (7.7% vs. 8.1%; P < 0.001). The number of medical complications (diabetic ketoacidosis, emergency department visits) was similar before and after pump start. There were fewer hypoglycemic events after pump start (12 vs. 17, rate ratio 0.46, 95% CI 0.21&#8211;1.01). CONCLUSIONS. This study suggests that pump therapy is safe and effective in selected children and adolescents with type 1 diabetes