Interaction-induced localization of anomalously-diffracting nonlinear waves

We study experimentally the interactions between normal solitons and tilted beams in glass waveguide arrays. We find that as a tilted beam, traversing away from a normally propagating soliton, coincides with the self-defocusing regime of the array, it can be refocused and routed back into any of the intermediate sites due to the interaction, as a function of the initial phase difference. Numerically, distinct parameter regimes exhibiting this behavior of the interaction are identified.Comment: Physical Review Letters, in pres

Layanan Bimbingan Pribadi-sosial Dalam Meningkatkan Komunikasi Interpersonal Peserta Didik Kelas XI SMA Negeri 2 Padang Cermin Kabupaten Pesawaran

Komunikasi merupakan bentuk tingkah laku seseorang baik verbal maupun non-verbal yang ditanggapi oleh orang lain. Setiap bentuk tingkah laku yang mengungkapkan pesan tertentu, sehingga juga merupakan sebentuk komunikasi. Berdasarkan hasil observasi dan penyebaran kuesioner yang penulis lakukan di SMA Negeri 2 Padang Cermin Kab. Pesawaran masih terdapat peserta didik kelas XI yang memiliki komunikasi interpersonal yang rendah seperti: berbicara pada saat ada yang sedang menyampaikan pesan, terbata-bata saat sedang menyampaikan pesan atau tujuan, sering menggunakan bahasa yang sulit dipahami sehingga mengakibatkan multitafsir, kemauan yang rendah untuk mengakui kesalahan dan cenderung menyalahkan orang lain, kurangnya rasa akrab, membantah perintah. Atas dasar hal tersebut peneliti mencoba menerapkan layanan bimbingan pribadi-sosial untuk meningkatkan komunikasi interpersonal peserta didik. Tujuan penelitian ini untuk mengetahui komunikasi interpersonal peserta didik dan untuk mengetahui apakah komunikasi interpersonal dapat ditingkatkan dengan menggunakan layanan bimbingan pribadi-sosial peserta didik kelas XI SMA Negeri 2 Padang Cermin Kb. Pesawaran. Metode yang digunakan dalam penelitian ini adalah penelitian pre-experimental dengan desain yang digunakan dalam penelitian ini one group pretest-posttest design. Sampel dalam penelitian berjmlah 10 peserta didik kelas XI SMA Negeri 2 Padang Cermin Kab. Pesawaran tahun pelajaran 2016/2017 yang memiliki komunikasi interpersonal rendah. Teknik pengumpulan data dalam penelitian ini menggunakan observasi, metode kuisioner, wawancara, dan dokumentasi tehnik pendukung. Hasil analisis data menunjukan bahwa terdapat peningkatan terhadap komunikasi interpersonal peserta didik di sekolah sebelum diberikan layanan konseling kelompok dan sesudah diberikan layanan. Hal ini ditunjukan dari pengujian hipotesis dengan menggunakan uji t (t-test), dari hasil pretest dan posttest yang diperoleh dalam kelompok eksperimen t hitung = 50.250 > t tabel 0.05 = 2.262, df= n-1= 10-1=9 dengan p value < t tabel (0.000 < 0.005), maka Ho ditolak dan Ha diterima yang bermakna layanan bimbingan pribadi-sosial dapat meningkatkan komunikasi interpersonal peserta didik. Saran yang diajukan peneliti yaitu kepada guru bimbingan perlu menindak lanjuti jika terdapat peserta didik yang mengalami hambatan atau kesulitan dalam bekomunikasi di lingkungannya. Karena hal ini dapat mempengaruhi peserta didik dalam proses berinteraksi serta belajar mengajar, dengan dapat menerapkan layanan konseling kelompok bimbingan pribadi-sosial

Energy expenditure in office workers with identified health risks

Objective. To measure the daily energy expenditure in employees previously identified as having &#8805;2 risk factors for chronic disease, and to identify potential risk-reducing interventions for implementation within or outside the workplace. Design. A total of 122 employees with &#8805;2 risk factors for chronic disease identified in an in-house screening programme were invited to participate in a 6-month health management programme. Physical assessments included anthropometric measurements, blood pressure, blood glucose and cholesterol estimations, and bicycle ergometry. Participants were invited to wear a ‘metabolic armband' (Body Media SenseWear Pro Armband®) for 6 days. Metabolic measures included active and total energy expenditure (AEE, TEE), and daily MET levels (metabolic equivalents expressed as kcal/kg/hour). Differences were explored between genders, and relationships sought between energy expenditure, lifestyle and anthropometric data. Setting. A corporate working environment. All measures and assessments were carried out in the in-house fitness facility. Interventions. The health management programme involved physical assessments and personalised weight and activity management plans. Main outcome measures. TEE per day, duration and quantification of physical activity, METS, AEE, number of steps per day and body position recording. Relationships were explored between the latter and anthropometric measures such as body mass index (BMI) and percentage body fat. Result. Altogether 53 (43%) of the eligible subjects volunteered for the 6-month programme and 49 enrolled for the metabolic armband study. The males were more active than the females, but both had BMI and body fat estimates that categorised them as overweight to obese. METS and AEE were positively correlated with duration of exercise rather than intensity, and negatively correlated with BMI. In a stepwise regression analysis for the total group 77% of the variance in MET levels was accounted for by per cent body fat and steps per day. Multivariate analysis by gender (with per cent body fat as the dependent variable) suggested that males would have to increase the duration of vigorous exercise in order to reduce body fat, while females would benefit from sitting less, sleeping more, and increasing the duration of moderate exercise. Conclusion and clinical relevance. In a self-selected sample involving motivated individuals, the SenseWear® armband provided information that would be useful in directing further research in women, focusing on sleeping pattern and moderately increasing activity levels. South African Journal of Sports Medicine Vol. 20 (2) 2008: pp. 40-4

Steps in the bacterial flagellar motor

The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437, 916--919]. Here we propose a simple physical model that accounts for this stepping behavior as a random walk in a tilted corrugated potential that combines torque and contact forces. We argue that the absolute angular position of the rotor is crucial for understanding step properties, and show this hypothesis to be consistent with the available data, in particular the observation that backward steps are smaller on average than forward steps. Our model also predicts a sublinear torque-speed relationship at low torque, and a peak in rotor diffusion as a function of torque

Contribution of particulate nitrate to airborne measurements of total reactive nitrogen

Simultaneous measurements of speciated, total reactive nitrogen (NOy) and particulate NO3 (particle diameter &lt;1.3 μm) were made on board the NASA P-3B aircraft over the western Pacific in February-April 2001 during the Transport and Chemical Evolution over the Pacific (TRACE-P) experiment. Gas-phase and particulate NOy was measured using a gold tube catalytic converter. For the interpretation of particulate NOy, conversion efficiencies of particulate NH4NO3, KNO3, NaNO3, and Ca(NO3)2 were measured in the laboratory. Only NH4NO3 showed quantitative conversion, and its conversion efficiency was as high as that for HNO3. NOy measured on board the aircraft was found to be systematically higher by 10-30% than the sum of the individual NOy gas components (Σ(NOy)i) at 0-4 km. Particulate NO3- concentrations measured by a particle-into-liquid sampler (PILS) were nearly equal to NOy - Σ(NOy)i under low-dust-loading conditions. The PILS data showed that the majority of the particulate NO3- was in the form of NH4NO3 under these conditions, suggesting that NH4NO3 particles were quantitatively converted to detectable NO by the NOy converter, consistent with the laboratory experiments. The contribution of particulate NO3- to NOy was most important at 0-2 km, where NO3- constituted 10-30% of NOy during TRACE-P. On average, the amounts of particulate NO3- and gas-phase HNO3 were comparable in this region. Copyright 2005 by the American Geophysical Union

Neutrino oscillations: Quantum mechanics vs. quantum field theory

A consistent description of neutrino oscillations requires either the quantum-mechanical (QM) wave packet approach or a quantum field theoretic (QFT) treatment. We compare these two approaches to neutrino oscillations and discuss the correspondence between them. In particular, we derive expressions for the QM neutrino wave packets from QFT and relate the free parameters of the QM framework, in particular the effective momentum uncertainty of the neutrino state, to the more fundamental parameters of the QFT approach. We include in our discussion the possibilities that some of the neutrino's interaction partners are not detected, that the neutrino is produced in the decay of an unstable parent particle, and that the overlap of the wave packets of the particles involved in the neutrino production (or detection) process is not maximal. Finally, we demonstrate how the properly normalized oscillation probabilities can be obtained in the QFT framework without an ad hoc normalization procedure employed in the QM approach.Comment: LaTeX, 42 pages, 1 figure; v2: minor clarifications, matches published version; v3: Corrected the discussion of the conditions under which an oscillation probability can be sensibly defined in the QFT approach (sec. 5.2.4