Scattering functions of knotted ring polymers

We discuss the scattering function of a Gaussian random polygon with N nodes under a given topological constraint through simulation. We obtain the Kratky plot of a Gaussian polygon of N=200 having a fixed knot for some different knots such as the trivial, trefoil and figure-eight knots. We find that some characteristic properties of the different Kratky plots are consistent with the distinct values of the mean square radius of gyration for Gaussian polygons with the different knots.Comment: 4pages, 3figures, 3table

Characteristic length of random knotting for cylindrical self-avoiding polygons

We discuss the probability of random knotting for a model of self-avoiding polygons whose segments are given by cylinders of unit length with radius $r$. We show numerically that the characteristic length of random knotting is roughly approximated by an exponential function of the chain thickness $r$.Comment: 5 pages, 4 figure

An Interprofessional Learning Opportunity Regarding Pain and the Opioid Epidemic

An interprofessional response is needed to mitigate the deleterious effects of the opioid epidemic. Here we describe an interprofessional workshop for n=307 students from social work, pharmacy, medicine, nursing, occupational therapy, physical therapy, and speech-language pathology designed to help prepare professionals to work competently in interprofessional teams while serving clients impacted by substance misuse. A total of n=201 participants provided informed consent and completed a pre- and post-test electronic survey to measure the influence of the interprofessional workshop. Findings from a paired sample t-test reveal statistically significant differences at post-test regarding participant’s self-described confidence 1) identifying their values and beliefs as they relate to substance misuse, 2) responding appropriately when interacting with someone with problematic substance use, 3) quickly finding local harm reduction resources, and 4) quickly finding local, available treatment resources for a person struggling with addiction. These findings suggest this educational curriculum is valuable in achieving its stated goals. Although future research is needed, findings from this study may be useful to health education systems across the country. This interprofessional education program can be emulated to aid in developing confidence in students and seasoned professionals in the healthcare workforce

CTNNB1, AXIN1 and APC expression analysis of different medulloblastoma variants

OBJECTIVES: We investigated four components of the Wnt signaling pathway in medulloblastomas. Medulloblastoma is the most common type of malignant pediatric brain tumor, and the Wnt signaling pathway has been shown to be activated in this type of tumor. METHODS: Sixty-one medulloblastoma cases were analyzed for β-catenin gene (CTNNB1) mutations, β-catenin protein expression via immunostaining and Wnt signaling pathway-related gene expression. All data were correlated with histological subtypes and patient clinical information. RESULTS: CTNNB1 sequencing analysis revealed that 11 out of 61 medulloblastomas harbored missense mutations in residues 32, 33, 34 and 37, which are located in exon 3. These mutations alter the glycogen synthase kinase-3β phosphorylation sites, which participate in β-catenin degradation. No significant differences were observed between mutation status and histological medulloblastoma type, patient age and overall or progression-free survival times. Nuclear β-catenin accumulation, which was observed in 27.9% of the cases, was not associated with the histological type, CTNNB1 mutation status or tumor cell dissemination. The relative expression levels of genes that code for proteins involved in the Wnt signaling pathway (CTNNB1, APC, AXIN1 and WNT1) were also analyzed, but no significant correlations were found. In addition, large-cell variant medulloblastomas presented lower relative CTNNB1 expression as compared to the other tumor variants. CONCLUSIONS: A small subset of medulloblastomas carry CTNNB1 mutations with consequent nuclear accumulation of β-catenin. The Wnt signaling pathway plays a role in classic, desmoplastic and extensive nodularity medulloblastoma variants but not in large-cell medulloblastomas

Gyration radius of a circular polymer under a topological constraint with excluded volume

It is nontrivial whether the average size of a ring polymer should become smaller or larger under a topological constraint. Making use of some knot invariants, we evaluate numerically the mean square radius of gyration for ring polymers having a fixed knot type, where the ring polymers are given by self-avoiding polygons consisting of freely-jointed hard cylinders. We obtain plots of the gyration radius versus the number of polygonal nodes for the trivial, trefoil and figure-eight knots. We discuss possible asymptotic behaviors of the gyration radius under the topological constraint. In the asymptotic limit, the size of a ring polymer with a given knot is larger than that of no topological constraint when the polymer is thin, and the effective expansion becomes weak when the polymer is thick enough.Comment: 12pages,3figure

On the Dominance of Trivial Knots among SAPs on a Cubic Lattice

The knotting probability is defined by the probability with which an $N$-step self-avoiding polygon (SAP) with a fixed type of knot appears in the configuration space. We evaluate these probabilities for some knot types on a simple cubic lattice. For the trivial knot, we find that the knotting probability decays much slower for the SAP on the cubic lattice than for continuum models of the SAP as a function of $N$. In particular the characteristic length of the trivial knot that corresponds to a `half-life' of the knotting probability is estimated to be $2.5 \times 10^5$ on the cubic lattice.Comment: LaTeX2e, 21 pages, 8 figur

Innovative biomass cooking approaches for sub-Saharan Africa.

Eradicating poverty and achieving food and nutrition security in a sustainable environment is difficult to achieve without adequate access to affordable cooking fuel. It is therefore important to understand the common sources of cooking energy used by people in rural areas and the challenges faced in making fuel sources economically viable, socially acceptable and ecologically sustainable. In the sub-Saharan Africa (SSA) region, more than 90% of the population relies on firewood and charcoal (wood fuel, collectively) as a primary source of domestic energy. Wood fuel sustainability is challenged by unsustainable harvesting and inefficient methods of converting wood into energy. The use of inefficient cook stoves contributes to wood wastage and smoke exposure associated with severe illnesses. Households often abandon traditional nutritious diets that take a long time to cook, reduce the number of meals, and spend income on fuel at the expense of food costs. Innovations exist that have the potential to provide affordable and cleaner tree-based cooking fuel. Pruning trees on the farm as a fuel source brings firewood closer to women, lightens their workload, saves time and reduces income spent on cooking fuel. Using briquettes or gas cook stoves can reduce health risks associated with food preparation and reduce income spent on cooking fuel due to increased fuel efficiency. The development of these innovations indicates the need for a multi-disciplinary approach to increase awareness of the benefits of cooking fuel innovations, encourage further research on product quality enhancement and standardization, to understand cultural and behavioral issues influencing adoption, and integrate innovations into bioenergy policy frameworks

アメリカ デノ ニホンゴ キョウイク ニ オケル コンピューター オヨビ インターネット ノ シヨウ ジョウキョウ チョウサ

テクノロジーを巡る我々の状況はここ10年で大きな変貌を遂げた。特にインターネットの出現により、我々の生活・教育はパラダイムシフトといってもよいほどの変化を見るに到った。現在、アメリカの公立学校の87% がインターネット環境を有するという報告さえあるほど、教育目的のインターネット利用はごく普通のものとなっているが、外国語教育もその例外ではない。 本稿では、アメリカの日本語教育現場でのコンピュータとインターネット使用について、アンケート調査を基に考察する。アンケート調査は、アメリカ全国規模の日本語教師団体二つの会員から、無作為抽出された500人を対象に、2002年4月に行なわれた。本調査では1) 教師のコンピュータの使用状況及び日本語環境とその技術支援、2) 学校での教室活動で使用可能なコンピューター数、3) 教室活動の一環として行われたテクノロジーのプロジェクト、という3点に的を絞り、データを収集した。その後、回収された243通の回答を、調査に参加した教師の教育機関レベルに3つのグループ(初等教育、中等教育、高等教育)に分け、比較・分析した。 結果、在米日本語教師は自分専用のコンピュータを所有しており、また高等教育に従事する教師が初等・中等教育の教師よりも新しいオペレーティングシステムを使用している傾向にあることがわかった。教育機関の日本語使用への技術支援が不足していることも判明した一方、多数の教師がインターネットを現場で積極的に使用していることも明らかになった。 多言語コンピューティングの発達に伴い、英語環境での日本語使用がより容易になった現在、日本語教師のテクノロジーの更なる有効利用を目指すためには、外国語教育の理論を考慮したテクノロジーの活用法に力を入れた教師研修が不可欠である。本稿では単に現状の分析結果だけではなく将来のテクノロジー活用の展望にも目を据えて報告する。Technology, especially the Internet, has advanced significantly in the last decade. Consequently, the wide spread use of the Internet in schools has been documented: In the United States, 87% of public schools have access to the Internet as of 2001. This advancement of and high accessibility to technology has encouraged technology use in foreign language education in the United States. The Japanese teaching field is assumed to be no exception, but in reality how much do Japanese teachers use computers for instructional purposes? To understand the current situation, a survey study was conducted involving practicing Japanese teachers in the United States. The survey questions addressed three areas: 1) the teacher’s environment for computing and Japanese capability, including technical support, 2) the availability of computers at school for class use, and 3) technology-related projects completed in class. The questionnaire was distributed in April 2002 to 500 teachers who were randomly selected from two national organizations of Japanese teachers in the United States. 243 responses were analyzed and compared among three different groups according to the school levels that the participants teach: elementary, middle/ high, and post-secondary. The results revealed that most teachers have exclusive access to computers with atendency for post-secondary school teachers to use newer operating systems than elementary and middle/ high school teachers. It was also found that many participating Japanese teachers lack technical support for Japanese software at their institutions. Nevertheless, the findings show that many teachers actively utilize the Internet in teaching. To further support Japanese teachers in their endeavor to take advantage of technology, more attention should be paid to the pedagogically sound implementation of it, as recent advances in multilingual computing have made Japanese capability less problematic than before