Deflation at Turnaround for Oscillatory Cosmology

It is suggested that dark energy in a brane world can help reconcile an infinitely cyclic cosmology with the second law of thermodynamics. A cyclic cosmology is described, in which dark energy with constant equation of state leads to a turnaround at finite future time, when entropy is decreased by a huge factor equal to the inverse of its enhancement during the initial inflation. Thermodynamic consistency of cyclicity requires the arrow of time to reverse during contraction. Entropy reduction in the contracting phase is infinitesimally smaller than entropy increase during expansion.Comment: 11 pages late

Dimensionality influence on passive scalar transport

We numerically investigate the advection of a passive scalar through an interface placed inside a decaying shearless turbulent mixing layer. We consider the system in both two and three dimensions. The dimensionality produces a different time scaling of the diffusion, which is faster in the two-dimensional case. Two intermittent fronts are generated at the margins of the mixing layer. During the decay these fronts present a sort of propagation in both the direction of the scalar flow and the opposite direction. In two dimensions, the propagation of the fronts exhibits a significant asymmetry with respect to the initial position of the interface and is deeper for the front merged in the high energy side of the mixing. In three dimensions, the two fronts remain nearly symmetrically placed. Results concerning the scalar spectra exponents are also presente

Entropy of Contracting Universe in Cyclic Cosmology

Following up a recent proposal \cite{BF} for a cyclic model based on phantom dark energy, we examine the content of the contracting universe (cu) and its entropy $S_{cu}$. We find that beyond dark energy the universe contains on average zero or at most a single photon which if present immediately after turnaround has infinitesimally energy which subsequently blue shifts to produce $e^+e^-$ pairs. These statements are independent of the equation of state $\omega = p/\rho$ of dark energy provided $\omega < -1$. Thus $S_{cu} = 0$ and if observations confirm $\omega < -1$ the entropy problem is solved. We discuss the absence of a theoretical lower bound on $\phi = |\omega + 1|$, then describe an anthropic fine tuning argument that renders unlikely extremely small $\phi$. The present bound $\phi \lesssim 0.1$ already implies a time until turnaround of $(t_T - t_0) \gtrsim 100$ Gy.Comment: 5 pages late

Promocijas darbs

Elektroniskā versija nesatur pielikumu

Towards a postcolonial conception on the right to access to justice

Uma releitura do acesso à justiça tem como primeiro desafio a denúncia do encerramento do debate sobre o acesso na simulação de uma tensão inexistente entre estrutura e ação em que esta última é sempre incorporada num processo de reforço e melhoria da primeira, o qual deve apoiar e pelo qual deve esperar. De um lado, vê-se a ação enquanto movimento implícito de mudança social que se dirige à expansão do papel das profissões e das estruturas jurídicas. De outro lado, o antagonismo criativo aos modos de funcionamento do direito e do Estado pela ação é simplificado como suplemento de participação no sistema jurídico, isto é, alternativas de acesso ao direito. Se não há lugar para a mudança radical da estrutura, o desvelar das ineficiências representam um eterno retorno da iniciativa de transformação à ação social. A revisão da compreensão de acesso à justiça requer, por isso, que se revisite as colaborações forjadas e as tensões ocultas na relação entre Estado e sociedade civil no que toca às reformas de ampliação do acesso ao direito. Este artigo procura depurar a conceção compreensiva do acesso à justiça, submetendo-a ao crivo de uma análise crítica do lugar do Estado e da sociedade civil na construção de políticas de acesso à justiça nos estados democráticos pós-modernos.A rereading of access to justice has as first challenge the denouncement of the closure of the debate on access to simulate a non-existent tension between structure and agency as the latter is always incorporated into a process of strengthening and improving the first, which it should support and whereby it should expect. On the one hand, one sees agency as implicit movement for social change that addresses the expanding role of legal professions and structures. On the other hand, the creative antagonism to the modes of production of the law and the State by agency is simplified as a participation supplement in the legal system, i.e. alternatives to access to justice. If there is no place for a radical change of the structure, the unveiling of the inefficiencies represent an eternal return of the transformation initiative to agency. Accordingly, a reconsideration of the understanding of access to justice requires revisiting forged collaborations and hidden tensions in the relationship between State and civil society with regard to access to law and justice legal reforms. This paper seeks to restore a comprehensive conception of access to justice, subjecting it to the scrutiny of a critical analysis of the role of the State and civil society in building access to justice policies in post-modern democratic states

Oligonukleotiidide hübridisatsioonimudeli rakendamine PCR-i ja mikrokiipide optimeerimiseks

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Nukleiinhapped on orgaaniliste makromolekulide hulgas unikaalsed tänu oma võimele kodeerida, dekodeerida ja kanda üle digitaalset informatsiooni. See omadus on aluseks nende kasutamisele arenevates tehnoloogiavaldkondades, alates kliinilisest diagnostikast kuni nanotehnoloogia ja informatsiooni talletamiseni. On aga oluline mõista, et digitaalse informatsiooni töötlemise ja säilitamise aluseks nukleiinhapetes on nende keemilised omadused. Tähtsaim nendest on hübridiseerumine - nukleiinhapete võime moodustada spontaanselt kaheahelaline heeliks kahe komplementaarse või osaliselt komplementaarse üheahelalise molekuli liitumisel. Nukleiinhapete hübridisatsiooni termodünaamika arvestamine võimaldab selle protsessi käitumist suure täpsusega modelleerida ja täiustada paljusid biotehnoloogilisi protsesse. Käesolevas väitekirjas on hübridisatsioonimudelit kasutatud multipleks-PCR-i ja detektsiooni mikrokiipide optimeerimiseks. Me töötasime välja ökonoomse algoritmi jaotamaks PCR praimeripaarid multipleksigruppidesse vastavalt nende omavahelisele sobivusele. Algoritm on realiseeritud nii iseseisva programmi kui veebirakendusena. Me uurisime multipleks PCR ebaõnnestumise põhjuseid ja näitasime, et suur arv mittespetsiifilisi seondumiskohti lähte DNA-l vähendab praimerite töötamise edukust. Need praimeripaarid, millel oli liiga suur arv mittespetsiifilisi seondumisi mitte ainult ei töötanud ise halvasti, vaid vähendasid ka teiste nendega koos amplifiseeritud praimeripaaride õnnestumise tõenäosust. Me töötasime välja arvutiprogrammi genereerimaks täieliku nimekirja kõigist võimalikest bakteriaalse tmRNA hübridiseerimisproovidest mis eristaksid omavahel kahte gruppi organisme. Proovide valideerimise käigus me näitasime, et valides hübridisatsioonienergia läviväärtuse suurema kui 4 kcl/mol on võimalik täielikult vältida valepositiivseid signaale. Me uurisime võimalust suurendada bakteriaalse RNA hübridiseerumiskiirust lisades lühikesi spetsiifilisi oligonukleotiide, mis hübridiseerudes lähtemolekulile ei lase selle sekundaarstruktuuril moodustuda. Seda meetodit kasutades tõusis hübridiseerumiskiirus temperatuuril 37C neli korda.Nucleic acids are unique among all organic macromolecules by the ability to encode, decode and transmit digital information. This property is used in emergent technologies as diverse as medical diagnosis, nanoscale engineering and information storage. Still it is important to understand that the basis of this digital information processing are the chemical properties of nucleic acids, the most important being the spontaneous formation of double-stranded helix between complementary or semi-complementary single-stranded molecules, called hybridization. Taking into account the thermodynamic properties of nucleic acid hybridization allows researchers to model the process with great accuracy and thus improve many associated technologies. In current thesis the hybridization model is used to optimize multiplex PCR and microarray hybridization. We developed an efficient algorithm to distribute PCR primer pairs into multiplex groups based on their compatibility with each other. The algorithm is also implemented as both standalone and web-based computer program. We analyzed the probable causes of failure of multiplex PCR and demonstrated that the large number of nonspecific hybridization sites in template DNA is detrimental to PCR quality. Primer pairs with too many nonspecific hybridization sites not only worked poorly but caused the failure of other primer pairs as well. We developed a computer program to generate exhaustive list of all possible hybridization probes for the detection of bacterial tmRNA, capable of distinguishing between two groups of source RNA. The probes were evaluated on microarray and shown that by keeping the hybridization energy cutoff between target and non-target groups over 4 kcal/mol all false-positive signals were eliminated. We analyzed the possibility of increasing the hybridization speed of bacterial tmRNA on low temperatures by applying short specific oligonucleotides that selectively hybridize with template molecules and break their secondary structure. Using this method the hybridization speed was increased fourfold at 37C

Energy-aware Sensor Data Collection for Mobile Users

Tänapäeval levib järjest rohkem rakendusi, mis tajuvad ümbritsevat keskkonda ning pakuvad sellele põhinevalt kasutajale lisavõimalusi. Selliste võimaluste pakkumiseks on arendatud prototüüp, mis kogub keskkonna kohta andmeid kasutades Arduino platvormil põhinevad sensorite moodulit ning keskset andmet kogumise serverit. Käesolevas töös arendati antud prototüüpi edasi, et tõsta aku vastupidavust ning seeläbi parandada lahenduse kasutatavust. Selleks loodi varieeruva sensoriandmete saatmise intervalliga lahendus, mis koosneb hägusloogikat kasutavast kontrollsüsteemist ning lihtsa lineaarse regressiooni mudelist. Lisaks loodi lahendus, mis lubab sensorite moodulil vabadel hetkedel minna puhkerežiimi. Töö käigus asendati seni kasutuselolev XMPP protokoll HTTP protokolli vastu, et parandada ühenduse loomise ajakulu ning lubada sensorite moodulil kauem puhkerežiimis olla. Parandatud lahenduse tulemusi mõõdeti mitme testi käigus. Kaks põhilist testi, mille käigus sensorite moodul sai voolu 9-voldiselt patareilt, andsid vastavalt tulemusteks 80 ja 110 \% pikema eluea. Sellest tulenevalt saab eeldada, et pakutud puhkerežiimi ja muutuva intervalliga andmete kogumist kasutav lahendus parandab aku vastupidavust ning seega ka prototüübi kasulikkust.Nowadays, mobile applications are becoming more context aware due to technological achievements which enable the applications to anticipate users’ intentions. This is achieved through using the device’s own micromechanical artifacts that can be used to perceive the environment. However, this is constrained to the hardware limitations of devices as not all devices provide the same options. Moreover, perceiving the environment strains the battery and therefore has its impact on devices' everyday usage. To remedy this, a proposed solution has been made in the thesis “Context Sensor Data on Demand for Mobile Users Supported by XMPP” by Kaarel Hanson. The solution is to gather environmental data by specialized sensor modules and store it in a data server. Afterwards, devices can query the data from the server and thus gain access to information beyond the capabilities of their own hardware. The solution uses XMPP for transporting sensor data from Arduino microcontrollers (sensor modules) to the cloud. Arduino provides low-cost hardware, while the cloud offers the reliable and high- availability means for storing and processing sensor data. However, the developed prototype shows that running on a 9V battery the microcontroller lasts for 101 minutes when using an Ethernet module and 161,5 minutes with a WiFi module. These results are not good enough for remote data collection with limited access as the maintenance cost would be too high when the batteries need to be replaced frequently. This thesis proposes an optimisation for the system so that instead of reading and sending sensor data every 10 seconds, the cloud server would notify the controller when to start sending data and when to stop. This means implementing an algorithm for detecting similar sensor data readings and notifying the microcontroller of needed operations. With similar readings, the microcontroller could be put to an idle state to limit power consumption, which would prolong battery life. The aim is to optimise the sensor reading process enough to prolong Arduino microcontroller’s battery life on a 9V battery

East Africa: Featuring Tanzania and Kenya

Suggested readings for the Penn Alumni travel trip to East Africa. See the Library Guide for this bibliography here

THE LEGAL PROTECTION OF FINANCIAL INTERESTS IN A DEMOCRATIC SOCIETY

Das Ziel des Artikels ist eine grundlegende Analyse des Finanzsektors in der Europäischen Union mit dem Schwerpunkt auf den Rechtschutz von Finanzinteressen vorzunehmen. Zur Umsetzung des Zieles werden die theoretischen Grundlagen für finanzielle Dienstleistungen und ihre Rechtsbedeutung beschrieben. Der Autor betrachtet Recht auf Eigentum als Menschenrecht und dessen rechtliche Bedeutung in einer modernen demokratischen Gesellschaft. Der Autor schlägt das Konzept der nachhaltigen Aufrechterhaltung der rechtlichen Regulierung im Finanzsektor analog zum Konzept von nachhaltigem Wachstum im Umweltrecht vor