Persamaan Diophantine Tipe Ramanujan-Nagell X2 = Yn + 2185

Dalam tulisannya di tahun 2014, Ulas mengajukan sebuah konjektur mengenai solusi bilangan bulat positif dari persamaan Ramanujan-Nagell x2 = yn + 2185. Di sini penulis termotivasi untuk melakukan penelitian lanjutan mengenai konjektur tersebut. Setelah dilakukan penelitian penulis berhasil membuktikan bahwa untuk kasus n bilangan genap solusinya adalah (x,y,n) = (59,6,4) dan (x,y,n) = (221,6,6), sementara untuk kasus n = 3 dengan x genap terbukti hanya terdapat satu pasangan solusi persamaan (x,y) = (248,39). Akan tetapi, untuk kasus n = 3 dengan x bilangan ganjil diatas belum diperoleh hasil yang memuaskan sehingga sangat perlu dilakukan penelitian lanjutan.On his paper in 2014, Ulas suggests a conjecture about positive integer solutions of equation Ramanujan-Nagell x2 = yn + 2185. In this paper, writer is motivated to conduct advanced research about the conjecture. In this research, writer has successfully proven that in case of n equals even number, the solutions are (x,y,n) = (59,6,4) dan (x,y,n) = (221,6,6), while in case of n = 3 with x is even number, it is proven that there is only one pair solution, that is (x,y) = (248,39). However, for n = 3 case with x is odd number, the satisfied result is not found yet, so the further research has to be done

Everyday Life Governance in Post-Soviet Uzbekistan

The issue of governance has become a fashionable topic of research in the study of post-Soviet societies. The key argument of this article is that there are multiple paradigms and understandings of ‘good governance’, some of which concur with the global (Western) understanding, while others offer alternative criteria. In this article, we explore the specifics of governance system in Uzbekistan and suggest the notion of ‘everyday life governance’ as shorthand for providing contextual understanding of good governance. This local Uzbek governance system consists of two important interrelated components: a government that heavily relies on coercive infrastructure for maintaining political stability and interethnic peace, but at the same time induces its citizens to engage in informal practices and networks as an alternative (to the formal) source of welfare. This article explores how this system emerged in the post-Soviet period and its impact on societal transformation, governance and development processes in Uzbekistan. These issues will be investigated with reference to observations and informal interviews from post-Soviet Uzbekistan. This study is based on three periods of ethnographic field research between 2009 and 2012 in the Ferghana Province of Uzbekistan.Peer reviewe

On the Feasibility of Maintenance Algorithms in Dynamic Graphs

Near ubiquitous mobile computing has led to intense interest in dynamic graph theory. This provides a new and challenging setting for algorithmics and complexity theory. For any graph-based problem, the rapid evolution of a (possibly disconnected) graph over time naturally leads to the important complexity question: is it better to calculate a new solution from scratch or to adapt the known solution on the prior graph to quickly provide a solution of guaranteed quality for the changed graph? In this paper, we demonstrate that the former is the best approach in some cases, but that there are cases where the latter is feasible. We prove that, under certain conditions, hard problems cannot even be approximated in any reasonable complexity bound --- i.e., even with a large amount of time, having a solution to a very similar graph does not help in computing a solution to the current graph. To achieve this, we formalize the idea as a maintenance algorithm. Using r-Regular Subgraph as the primary example we show that W[1]-hardness for the parameterized approximation problem implies the non-existence of a maintenance algorithm for the given approximation ratio. Conversely we show that Vertex Cover, which is fixed-parameter tractable, has a 2-approximate maintenance algorithm. The implications of NP-hardness and NPO-hardness are also explored

A King’s Secret: The Reason for Regression in a 14-Month-Old Male

A 14-month-old male with constipation and a recent viral exanthem presents with 8 weeks of progressive gross motor regression. He no longer walks, crawls, or sits unassisted. No loss of social, speech, or fine motor milestones. No fever, rash, cough, congestion, or diarrhea. No known trauma. Family history negative for muscle, nerve, autoimmune, and developmental conditions. He was born abroad and lived on a dairy farm in New Zealand until 5 months ago. Vaccines up to date. Recently exposed to raw honey and a petting zoo. Neurologic and musculoskeletal exams pertinent for refusal to bear weight or crawl. Resists sitting as well as flexion or extension of hips. Moves all extremities purposefully and spontaneously. Rolls over in both directions. Head lag present. Achilles reflexes 1+ bilaterally. No eyelid drooping, facial asymmetry, or trouble swallowing. Exam was otherwise unremarkable. CBC and iron studies revealed microcytic iron deficiency anemia, thyroid studies showed subclinical hypothyroidism, and mild elevation of CRP and ESR present. Screening metabolic and leukodystrophy workup unremarkable. MRI brain with bilateral confluent T2 signal hypersensitivity in the periventricular white matter. MRI spine notable for destruction of the L2-L3 disc with 4mm fluid collection within the disc space consistent with spondylodiscitis. Interventional radiology performed disc space aspiration and bone biopsy for culture. Empiric IV cefazolin initiated. Biopsy culture returned positive for Kingella kingae, sensitive to cefazolin. His imaging and culture findings were consistent with a diagnosis of L2-L3 spondylodiscitis. He completed 6 weeks of IV antibiotics. Repeat MRI showed significant improvement with near complete resolution. With ongoing physical therapy he is now crawling, cruising, and sitting with improving endurance. Spondylodiscitis encompasses both infectious discitis and vertebral osteomyelitis. Common presenting symptoms include back pain, limp, fever, irritability, and refusal to walk. Diagnosis is often delayed in children because of the rarity (estimated 2-4 cases per 1,000,000 per year), but also complicated because of poorly defined manifestations in children who are often not able to vocalize symptoms, requiring a high index of suspicion. The most common pathogen is Staphylococcus aureus, however there has been an increase in Kingella kingae reported in recent literature that must be considered when choosing empiric therapy.https://digitalcommons.unmc.edu/chri_forum/1055/thumbnail.jp

Lessons from AI: communication

Metals in Catalysis, Biomimetics & Inorganic Material

Visualization and Analysis Techniques for Three Dimensional Information Acquired by Confocal Microscopy

Confocal Scanning Laser Microscopy (CSLM) is particularly well suited for the acquisition of 3-dimensional data of microscopic objects. In the CSLM a specific volume in the object is sampled during the imaging process and the result is stored in a digital computer as a three-dimensional memory array. Optimal use of these data requires both the development of effective visual representations as well as analysis methods. In addition to the well known stereoscopic representation method a number of alternatives for various purposes are presented. When rendering in terms of solid-looking or semitransparent objects is required, an algorithm based on a simulated process of excitation and fluorescence is very suitable. Graphic techniques can be used to examine the 3-dimensional shape of surfaces. For (near-)real time applications a representation method should not require extensive previous data-processing or analysis. From the very extensive field of 3-D image analysis two examples are given

Nuttalliella namaqua: A Living Fossil and Closest Relative to the Ancestral Tick Lineage: Implications for the Evolution of Blood-Feeding in Ticks

Ticks are monophyletic and composed of the hard (Ixodidae) and soft (Argasidae) tick families, as well as the Nuttalliellidae, a family with a single species, Nuttalliella namaqua. Significant biological differences in lifestyle strategies for hard and soft ticks suggest that various blood-feeding adaptations occurred after their divergence. The phylogenetic relationships between the tick families have not yet been resolved due to the lack of molecular data for N. namaqua. This tick possesses a pseudo-scutum and apical gnathostoma as observed for ixodids, has a leathery cuticle similar to argasids and has been considered the evolutionary missing link between the two families. Little knowledge exists with regard to its feeding biology or host preferences. Data on its biology and systematic relationship to the other tick families could therefore be crucial in understanding the evolution of blood-feeding behaviour in ticks. Live specimens were collected and blood meal analysis showed the presence of DNA for girdled lizards from the Cordylid family. Feeding of ticks on lizards showed that engorgement occurred rapidly, similar to argasids, but that blood meal concentration occurs via malpighian excretion of water. Phylogenetic analysis of the 18S nuclear and 16S mitochondrial genes indicate that N. namaqua grouped basal to the main tick families. The data supports the monophyly of all tick families and suggests the evolution of argasid-like blood-feeding behaviour in the ancestral tick lineage. Based on the data and considerations from literature we propose an origin for ticks in the Karoo basin of Gondwanaland during the late Permian. The nuttalliellid family almost became extinct during the End Permian event, leaving N. namaqua as the closest living relative to the ancestral tick lineage and the evolutionary missing link between the tick families