Constructing lattice bases by means of approximations

The construction of a basis of a certain lattice of interest is a basic tool in many fields of algorithmic number theory. All too often we can not compute with the original lattices because of irrational numbers involved but have to work with approximations of them. While helpful bounds were shown about the reduction of lattice bases in cite{buchmann94reducing}, here we introduce the notion of a $(epsilon,delta)$-constructable basis of a lattice and determine the precision of vectors that is necessary to extend a set to a $(epsilon,delta)$-constructable basis

A quantum algorithm for computing the unit group of an arbitrary degree number field

Computing the group of units in a field of algebraic numbers is one of the central tasks of computational algebraic number theory. It is believed to be hard classically, which is of interest for cryptography. In the quantum setting, efficient algorithms were previously known for fields of constant degree. We give a quantum algorithm that is polynomial in the degree of the field and the logarithm of its discriminant. This is achieved by combining three new results. The first is a classical algorithm for computing a basis for certain ideal lattices with doubly exponentially large generators. The second shows that a Gaussian-weighted superposition of lattice points, with an appropriate encoding, can be used to provide a unique representation of a real-valued lattice. The third is an extension of the hidden subgroup problem to continuous groups and a quantum algorithm for solving the HSP over the group ℝ^n

In situ analysis of FOXP3+ regulatory T cells in human colorectal cancer

The immune system spontaneously responds to tumor-associated antigens in peripheral blood of colorectal cancer (CRC) patients. Regulatory T cells (Treg) are suspected of influencing the interaction between the tumor and immune system and thus the course of malignant diseases. However, the function of Tregs in the development of T cell responses and on the clinical course of CRC is not clear. We analyzed Treg infiltration (FOXP3 staining) in situ in 40 CRC patients and investigated whether there is a correlation to disease stage, systemic T cell response, and survival. Treg infiltration was significantly higher in CRC than in healthy colon. Stromal Treg infiltration was significantly higher than epithelial infiltration in CRC. Furthermore, Treg infiltration in the tumor was significantly higher in limited disease than in metastatic CRC. The average Treg infiltration rate in the tumor was non-significantly higher in patients without systemic TAA-specific T cell response. Survival did not differ between patients with high Treg infiltration and those with low Treg infiltration. In conclusion, a direct link between Treg infiltration in the tumor and the development of a systemic T cell response in CRC cannot be proven. However, local Treg infiltration was significantly higher in limited disease, in which a systemic TAA-directed T cell responses is less frequently observed

Modeling of Mass Balance Variability and Its Impact on Water Discharge from the Urumqi Glacier No. 1 Catchment, Tian Shan, China

Originating in the Tian Shan mountains, Urumqi River plays a key role in terms of water supply to downstream areas. In its headwaters, Urumqi Glacier No. 1 (UG1) is the largest glacier contributing to water discharge. Assessing its response to the changing climatic conditions in the area is of major importance to quantify future water availability. We here apply COSIPY, a COupled Snowpack and Ice surface energy and mass balance model in PYthon, to UG1, implementing a new albedo parameterization which integrates site-specific bare-ice albedo values on a pixel-by-pixel basis observed by remote sensing. We assess model performance threefold: quantitatively based on long-term measurement data of (1) surface mass balance (SMB) and (2) water discharge as well as qualitatively (3) comparing simulated snow line altitudes to such imated on the basis of time-lapse photography. Comparison of the modeled SMB with annually-averaged data from ablation stakes reveals that COSIPY including the new albedo parameterization accounts for 57.6% of the variance observed in the measurements. The original albedo parameterization performs only slightly inferior (57.1%). Glacier-wide comparison between modeled and glaciological SMB shows high agreement. In terms of discharge prediction, COSIPY reproduces onset and duration of the discharge season well. Estimated discharge from the whole catchment shows shortcomings in exactly matching the measured times series, but interannual variability is captured.Peer Reviewe

Freeze-Thaw Deicing salt Attack on Concrete: Towards Engineering Modelling

In order to reduce carbon dioxide emissions, the construction sector is increasingly using clinker-reduced concretes. Concrete with high amounts of ground granulated blast furnace slag (GGBFS) show increased durability performance in certain environmental conditions compared to concrete with Ordinary Portland cement (OPC). However, in laboratory studies, concrete with GGBFS show an increased initial scaling rate in comparison with OPC concrete. Changing weather conditions and high relative humidities > 70 % in field lead to less carbonation and thus, to a better freeze-thaw deicing salt resistance (FTDSR). Therefore, the current lab performance test penalizes GGBFS concrete. This contribution studied the impact of carbonation and intermittent dry periods on FTDSR of GGBFS concrete compared to that of OPC concrete. It could be shown that for concrete with OPC, intermittent dry periods lead to an accumulation of salt in the near surface, which causes a reduction of the scaling. GGBFS concrete, on the other hand, shows an opposite behavior: carbonation causes an increase in scaling after the dry period. GGBFS concrete samples with CO2-free pre-storage show the lowest scaling of all samples investigated. A better simulation of the behavior of GGBFS concrete could lead to economical as well as optimized solutions for the local environment conditions and enable the large-scale use of more environmentally-friendly concretes. Therefore, by taking the effect of carbonation and intermittent dry periods into account in a simple engineering model, the prediction of concrete scaling under consideration of real climatic conditions is possible in an eco-efficient manner

Mindfulness-based cognitive therapy in obsessive-compulsive disorder – A qualitative study on patients’ experiences

BACKGROUND: Cognitive behavioral therapy (CBT) with exposure and response prevention (ERP) is the first-line treatment for patients with obsessive-compulsive disorder (OCD). However, not all of them achieve remission on a longterm basis. Mindfulness-based cognitive therapy (MBCT) represents a new 8-week group therapy program whose effectiveness has been demonstrated in various mental disorders, but has not yet been applied to patients with OCD. The present pilot study aimed to qualitatively assess the subjective experiences of patients with OCD who participated in MBCT. METHOD: Semi-structured interviews were conducted with 12 patients suffering from OCD directly after 8 sessions of a weekly MBCT group program. Data were analyzed using a qualitative content analysis. RESULTS: Participants valued the treatment as helpful in dealing with their OCD and OCD-related problems. Two thirds of the patients reported a decline in OCD symptoms. Benefits included an increased ability to let unpleasant emotions surface and to live more consciously in the present. However, participants also discussed several problems. CONCLUSION: The data provide preliminary evidence that patients with OCD find aspects of the current MBCT protocol acceptable and beneficial. The authors suggest to further explore MBCT as a complementary treatment strategy for OCD