Topics in Software Engineering

Software engineering is a discipline which specifies, designs, develops, and maintains software applications. It applies practices and technologies from computer science. Software engineering is the backbone of software systems and forms the basis of operational design and development of software systems. Analysts use requirements elicitation techniques to ascertain the needs of customers and users, with the goal being a system that has a high chance of satisfying those needs. Success or failure of system development relies heavily on the quality of requirements gathering. Software modeling is an essential part of the software development process. Models are built and analyzed before the implementation of a system and are used to direct implementation.The Unified Modeling Language (UML) provides a standard way to visualize the design of a system. During the planning and design stages, software engineers must consider the risks involved in developing a system. Software must solve a problem and must respond to both functional and nonfunctional requirements. Software systems generally follow a pattern or an architectural style. We show the initial steps of developing a software system, define its specification and design topics, and demonstrate their creation by presenting a case study

Die Veränderung der perizellulären Mikroumgebung im hyalinen Knorpel bei Arthrose

Arthrose als weltweit sehr häufige degenerative Gelenkerkrankung geht bisher mit einem schmerzhaften chronisch progressiven Verlauf ohne Aussicht auf Heilung einher. Hierbei kommt es primär zu einer Destruktion des hyalinen Gelenkknorpels. Untersuchungen zeigen, dass schon früh mikroskopisch Änderungen der Knorpelstruktur und der zellulären Anordnung beobachtet werden können, bevor makroskopische Veränderungen sichtbar werden. Die Einteilung nach der zellulären Organisation eröffnet die Möglichkeit, die Zellmuster als bildbasierten Biomarker zu verwenden. Die Chondrozyten sind im intakten Knorpel umgeben von ihrer perizellulären Matrix (PZM,) die die Zellen geflechtartig wie eine Kapsel umgibt. Als wichtige Schnittstelle zwischen der Zelle und ihrer Umgebung erfüllt sie viele Funktionen in Bezug auf die Zellkommunikation, die Modulation der Zellbiosynthese, den Zellschutz vor Apoptose und Inflammation, der Zellintegrität und der biomechanischen Übertragung und Verteilung wirkender Kräfte auf die Zellen. In der aktuellen Arbeit wurden die Veränderungen der Strukturproteine der PZM Kollagen Typ VI, Kollagen Typ III, Perlekan, Biglykan und Fibrillin-1 bei Arthrose als Funktion der veränderten zellulären Organisation untersucht. Dazu wurde der hyaline Gelenkknorpel der Femurkondylen von Patienten mit Gonarthrose verwendet. Die untersuchten Strukturproteine wurden mittels Immunfluoreszenz sichtbar gemacht und anschließend semiquantitativ und qualitativ ausgewertet. Die Hypothese, dass die Integrität der PZM im Verlauf der zellulären Umorganisation stark abnimmt und sich die Zusammensetzung ändert, konnte bestätigt werden. Es zeigte sich für die untersuchten Proteine ein individueller Verlauf, allerdings konnte durchweg eine Zerstörung der kapselartigen Struktur mit fortschreitender zellulärer Organisationänderung beobachtet werden. Durch die Beteiligung der Strukturproteine an verschiedenen Stoffwechselprozessen im Knorpel liegt es nahe, dass sich die Änderungen in der PZM direkt auf den Metabolismus auswirken. Des Weiteren sind vermutlich die anderen Funktionen wie der Schutz der Zellen und die koordinierte Übertragung wirkender Kräfte nicht mehr gewährleistet

CP Violation in Supersymmetric U(1)' Models

The supersymmetric CP problem is studied within superstring-motivated extensions of the MSSM with an additional U(1)' gauge symmetry broken at the TeV scale. This class of models offers an attractive solution to the mu problem of the MSSM, in which U(1)' gauge invariance forbids the bare mu term, but an effective mu parameter is generated by the vacuum expectation value of a Standard Model singlet S which has superpotential coupling of the form SH_uH_d to the electroweak Higgs doublets. The effective mu parameter is thus dynamically determined as a function of the soft supersymmetry breaking parameters, and can be complex if the soft parameters have nontrivial CP-violating phases. We examine the phenomenological constraints on the reparameterization invariant phase combinations within this framework, and find that the supersymmetric CP problem can be greatly alleviated in models in which the phase of the SU(2) gaugino mass parameter is aligned with the soft trilinear scalar mass parameter associated with the SH_uH_d coupling. We also study how the phases filter into the Higgs sector, and find that while the Higgs sector conserves CP at the renormalizable level to all orders of perturbation theory, CP violation can enter at the nonrenormalizable level at one-loop order. In the majority of the parameter space, the lightest Higgs boson remains essentially CP even but the heavier Higgs bosons can exhibit large CP-violating mixings, similar to the CP-violating MSSM with large mu parameter.Comment: 29 pp, 3 figs, 2 table

Progressive skin fibrosis is associated with a decline in lung function and worse survival in patients with diffuse cutaneous systemic sclerosis in the European Scleroderma Trials and Research (EUSTAR) cohort.

Objectives To determine whether progressive skin fibrosis is associated with visceral organ progression and mortality during follow-up in patients with diffuse cutaneous systemic sclerosis (dcSSc). Methods We evaluated patients from the European Scleroderma Trials and Research database with dcSSc, baseline modified Rodnan skin score (mRSS) ≥7, valid mRSS at 12±3 months after baseline and ≥1 annual follow-up visit. Progressive skin fibrosis was defined as an increase in mRSS >5 and ≥25% from baseline to 12±3 months. Outcomes were pulmonary, cardiovascular and renal progression, and all-cause death. Associations between skin progression and outcomes were evaluated by Kaplan-Meier survival analysis and multivariable Cox regression. Results Of 1021 included patients, 78 (7.6%) had progressive skin fibrosis (skin progressors). Median follow-up was 3.4 years. Survival analyses indicated that skin progressors had a significantly higher probability of FVC decline ≥10% (53.6% vs 34.4%; p<0.001) and all-cause death (15.4% vs 7.3%; p=0.003) than non-progressors. These significant associations were also found in subgroup analyses of patients with either low baseline mRSS (≤22/51) or short disease duration (≤15 months). In multivariable analyses, skin progression within 1 year was independently associated with FVC decline ≥10% (HR 1.79, 95% CI 1.20 to 2.65) and all-cause death (HR 2.58, 95% CI 1.31 to 5.09). Conclusions Progressive skin fibrosis within 1 year is associated with decline in lung function and worse survival in dcSSc during follow-up. These results confirm mRSS as a surrogate marker in dcSSc, which will be helpful for cohort enrichment in future trials and risk stratification in clinical practice

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

The neutron and its role in cosmology and particle physics

Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic

Entwicklungsauffälligkeiten von Kindern Crystal-Meth-abhängiger Eltern

Die vorliegende Bachelorarbeit befasst sich mit den möglich entstehenden Entwicklungsauffälligkeiten von Kindern, deren Eltern Crystal Meth-abhängig sind. Der Fokus in der Arbeit liegt auf der sozial-emotionalen Entwicklung in der frühen Kindheit. Zunächst werden Grundlagen über die kindliche Entwicklung skizziert und Erklärungen zu Sucht und Abhängigkeit dargereicht. Anschließend werden Informationen über die Droge Crystal Meth angebracht. Im Hauptteil wird auf die Auffälligkeiten der sozial-emotionalen Entwicklung von Kindern drogenabhängiger Eltern eingegangen. Zudem wurde herausgearbeitet, welche Verhaltensänderungen der Eltern mögliche Auffälligkeiten der kindlichen Entwicklung begünstigen. Die Betrachtung von drogenabhängigen- und speziell Crystal Meth-abhängigen Eltern soll als Vergleich dienen. Diese Arbeit wurde auf Basis von Literaturrecherchen erstellt und unter Einbeziehung einiger Studien ergänzt

Personalized Biopsy Schedules Using an Interval-censored Cause-specific Joint Model

Active surveillance (AS), where biopsies are conducted to detect cancer progression, has been acknowledged as an efficient way to reduce the overtreatment of prostate cancer. Most AS cohorts use fixed biopsy schedules for all patients. However, the ideal test frequency remains unknown, and the routine use of such invasive tests burdens the patients. An emerging idea is to generate personalized biopsy schedules based on each patient's progression-specific risk. To achieve that, we propose the interval-censored cause-specific joint model (ICJM), which models the impact of longitudinal biomarkers on cancer progression while considering the competing event of early treatment initiation. The underlying likelihood function incorporates the interval-censoring of cancer progression, the competing risk of treatment, and the uncertainty about whether cancer progression occurred since the last biopsy in patients that are right-censored or experience the competing event. The model can produce patient-specific risk profiles until a horizon time. If the risk exceeds a certain threshold, a biopsy is conducted. The optimal threshold can be chosen by balancing two indicators of the biopsy schedules: the expected number of biopsies and expected delay in detection of cancer progression. A simulation study showed that our personalized schedules could considerably reduce the number of biopsies per patient by 34%-54% compared to the fixed schedules, though at the cost of a slightly longer detection delay