Gr\"obner Bases over Algebraic Number Fields

Although Buchberger's algorithm, in theory, allows us to compute Gr\"obner bases over any field, in practice, however, the computational efficiency depends on the arithmetic of the ground field. Consider a field $K = \mathbb{Q}(\alpha)$, a simple extension of $\mathbb{Q}$, where $\alpha$ is an algebraic number, and let $f \in \mathbb{Q}[t]$ be the minimal polynomial of $\alpha$. In this paper we present a new efficient method to compute Gr\"obner bases in polynomial rings over the algebraic number field $K$. Starting from the ideas of Noro [Noro, 2006], we proceed by joining $f$ to the ideal to be considered, adding $t$ as an extra variable. But instead of avoiding superfluous S-pair reductions by inverting algebraic numbers, we achieve the same goal by applying modular methods as in [Arnold, 2003; B\"ohm et al., 2015; Idrees et al., 2011], that is, by inferring information in characteristic zero from information in characteristic $p > 0$. For suitable primes $p$, the minimal polynomial $f$ is reducible over $\mathbb{F}_p$. This allows us to apply modular methods once again, on a second level, with respect to the factors of $f$. The algorithm thus resembles a divide and conquer strategy and is in particular easily parallelizable. At current state, the algorithm is probabilistic in the sense that, as for other modular Gr\"obner basis computations, an effective final verification test is only known for homogeneous ideals or for local monomial orderings. The presented timings show that for most examples, our algorithm, which has been implemented in SINGULAR, outperforms other known methods by far.Comment: 16 pages, 1 figure, 1 tabl

Suspended sediment transport in a mountainous catchment

Thesis--University of Tsukuba, D.Sc.(A), no. 881, 1991. 3. 2

Hemodynamic and autonomic response to acute hemorrhage in streptozotocin-induced diabetic rats

<p>Abstract</p> <p>Background</p> <p>The various autonomic control systems lead to characteristic changes in heart rate (HR) and blood pressure (BP) during acute hemorrhage. However, cardiovascular autonomic neuropathy due to diabetes mellitus may interfere with the normal compensation for hemorrhage.</p> <p>Materials and methods</p> <p>A controlled graded bleeding (6 - 36% loss of estimated total blood volume: ETBV) was performed in streptozotocin-induced diabetic rats (STZ rats) under a conscious state. Hemodynamic and autonomic responses to acute hemorrhage were examined using analysis of BP-HR variability. The effects of dextran treatment after hemorrhage were also examined.</p> <p>Results</p> <p>A significant reduction in mean arterial pressure began at 12% ETBV loss in STZ rats and 18% in the control rats, respectively. When blood loss reached 18% of TEBV, the decrease in HR was prominent in STD rats due to the activation of a parasympathetic drive, as indicated by the increase in high frequency (HF; 0.75~3.0 Hz) power in HR variability, while in the control rats this response was not observed. The administration of dextran prevented the activation of the parasympathetic drive in STZ rats during hemorrhaging. In the control rats, the dextran treatment sustained the initial increase in HR with reduced HF power in HR variability.</p> <p>Conclusion</p> <p>STZ rats showed different hemodynamic and autonomic responses to acute hemorrhage from the control rats. STZ rats were prone to develop bradycardiac hypotension characterized by marked parasympathetic activation during hemorrhaging. This finding suggests enhancement of the Bezold-Jarisch reflex in STZ rats. Dextran treatment to maintain a normovolemic hemorrhage state inhibits this reflex.</p

Pengaruh Quick Ratio (QR) dan Debt to Equity Ratio (DER) terhadap Return On Asset (ROA): Studi pada PT Gudang Garam Tbk periode 2010-2019

Hasil penelitian menunjukkan bahwa secara parsial Quick Ratio maupun Debt to Equity Ratio tidak memberikan pengaruh signifikan terhadap Return On Asset pada PT Gudang Garam Tbk periode 2010 sampai 2019. Dilihat dari hasil pengujian uji t pada Quick Ratio yang menunjukan bahwa nilai thitung lebih kecil daripada ttabel (0,574 0,05) dan hasil pengujian uji t pada Debt to Equity Ratio menunjukan bahwa nilai thitung lebih kecil daripada ttabel (-2,047 0,05). Kemudian pada uji F didapatkan hasil yang menunjukan nilai Fhitung lebih besar dari Ftabel (6,131 > 4,46) dengan nilai signifikansinya lebih kecil dari α (0,029 < 0,05) yang berarti Quick Ratio dan Debt to Equity ratio secara bersama-sama atau simultan signifikan memberikan pengaruh terhadap Return On Asset. Sedangkan pada pengujian determinasi berganda (R2) menunjukan variabel Quick Ratio dan Debt to Equity Ratio memberikan pengaruh sebesar 0,637 atau 63,7%, sedangkan sisanya sebesar 36,3% dipengaruhi oleh faktor-faktor lain yang tidak diteliti dalam penelitian ini

Climate change, migration and conflict : a case study of Kilosa district, Tanzania

Master thesis development management- University of Agder, 2014This thesis discusses the impacts of climate change on rural and urban households in Kilosa district and focuses on investigating the linkage between climate change, migration and conflict in the district. Different scholars argue that climate change is a fundamental threat to sustainable development in developing countries unless vital actions taken before the warming planet threatens to put prosperity out of reach of millions and roll back decades of development. Moreover, academics and security analysts have warned for some time now that climate change threatens water, food security, and the allocation of resources. Such impacts could further allege to increase forced migration, raise tensions and trigger conflict. Sub-Saharan Africa is one of the most vulnerable regions in the world to climate change because of widespread poverty and limited adaptive capacity. Moreover, future climate change is likely to pose severe impact in a developing country like Tanzania because of weak socioeconomic structures and agrarian economy. Tanzania is already under stress from series of climate change impacts, especially, in its arid and semi-arid regions. The study area, Kilosa district, is one of the climate change and variability-prone areas in the country. The environmental challenges within the district and in the neighboring areas have had an adverse impact on the development endeavors in the region. The district has also experienced high rates of frequent human mobility and conflict. Hence, the research findings show how climate change affects the livelihood of rural and urban households by instigating human mobility and conflict in Kilosa district. It also discusses climate change adaptation strategies and conflict resolution initiatives in the study area

Premedication with midazolam in intellectually disabled dental patients: intramuscular or oral administration? A retrospective study

Background: The use of midazolam for dental care in patients with intellectual disability is poorly documented. The purpose of this study was to determine which method of premedication is more effective for these patients, 0.15 mg/kg of intramuscular midazolam or 0.3 mg/kg of oral midazolam. Material and Methods: This study was designed and implemented as a non-randomized retrospective study. The study population was composed of patients with intellectual disability who required dental treatment under ambulatory general anesthesia from August 2009 through April 2013. Patients were administered 0.15 mg/kg of midazolam intramuscularly (Group IM) or 0.3 mg/kg orally (Group PO). The predictor variable was the method of midazolam administration. The outcome variables measured were Observer’s Assessment of Alertness/ Sedation (OAA/S) Scale scores, the level of cooperation when entering the operation room and for venous cannulation, post-anesthetic agitation and recovery time. Results: Midazolam was administered intramuscularly in 23 patients and orally in 21 patients. More patients were successfully sedated with no resistance behavior during venous cannulation in Group PO than in Group IM ( p =0.034). There were no differences in demographic data and other variables between the groups. Conclusions: The results of this study suggest that oral premedication with 0.3 mg/kg of midazolam is more effective than 0.15 mg/kg of midazolam administered intramuscularly, in terms of patient resistance to venous cannulation. If both oral and intramuscular routes of midazolam are acceptable in intellectually disabled patients, the oral route is recommended