Communication skills Assessed at OSCE are not Affected by Participation in the Adolescent Healthy Sexuality Program

Purpose: We proposed that first year medical students who voluntarily participated in the Healthy Sexuality adolescent program would perform better than their peers on an adolescent counseling station at the year-end OSCE (Objective Structured Clinical Examination). In addition we compared medical students’ communication skills at the time of the program as assessed by self, peers and participating adolescents. Methods: Nineteen first year medical students voluntarily participated in the ongoing Healthy Sexuality program. Adolescent participants, medical student peer participants and medical students assessed communication components on a 7-point Likert scale at the end of the program. At the year-end OSCE, all first year medical students at the University of Western Ontario were assessed at an adolescent counseling station by a standardized patient (SP) and a physician examiner. Statistical analysis examined differences between the two groups. Results: Students who participated in the Healthy Sexuality program did not perform better than their colleagues on the year-end OSCE. A statistically significant correlation between physician examiner and SP evaluations was found (r = 0.62). Adolescent participants communication skills assessments in the Healthy Sexuality Program demonstrated no significant correlation with medical student assessments (self or peer). Conclusions:Voluntary intervention with adolescents did not result in improved communication skills at the structured year-end examination. Further investigation will be directed towards delineating differences between SP and physician examiner assessment

Using Tuangou to reduce IP transit costs

A majority of ISPs (Internet Service Providers) support connectivity to the entire Internet by transiting their traffic via other providers. Although the transit prices per Mbps decline steadily, the overall transit costs of these ISPs remain high or even increase, due to the traffic growth. The discontent of the ISPs with the high transit costs has yielded notable innovations such as peering, content distribution networks, multicast, and peer-to-peer localization. While the above solutions tackle the problem by reducing the transit traffic, this paper explores a novel approach that reduces the transit costs without altering the traffic. In the proposed CIPT (Cooperative IP Transit), multiple ISPs cooperate to jointly purchase IP (Internet Protocol) transit in bulk. The aggregate transit costs decrease due to the economies-of-scale effect of typical subadditive pricing as well as burstable billing: not all ISPs transit their peak traffic during the same period. To distribute the aggregate savings among the CIPT partners, we propose Shapley-value sharing of the CIPT transit costs. Using public data about IP traffic of 264 ISPs and transit prices, we quantitatively evaluate CIPT and show that significant savings can be achieved, both in relative and absolute terms. We also discuss the organizational embodiment, relationship with transit providers, traffic confidentiality, and other aspects of CIPT

A Class Of Functional Equations And Mielnik Probability Spaces

Let S be the unit sphere of a normed real linear space N and let (S, p) be a Mielnik space of dimension two. For p(x, y) = f(‖x+y‖), x, yєS, where /is a continuous, strictly increasing function from [0, 2] onto [0, 1], it has been shown that (S, p) being two dimensional is equivalent to N being an inner product space. In some polarization problems modeled on the unit sphere of an inner product space, the transition probability p(x, y) may not be as well behaved as p(x, y) = f(‖x + y‖). In order to provide a more suitable setting, we have constructed wide classes of two-dimensional transitional probability spaces (S, p), all having the same set of bases ℬ with p=⌽ ° f where ⌽ is a solution of a certain functional equation. In particular, for p(x, y) = ‖x+y‖24, we answer a question due to B. Mielnik. © American Mathematical Society 1976

Correlations of Rydberg excitations in an ultra-cold gas after an echo sequence

We show that Rydberg states in an ultra-cold gas can be excited with strongly preferred nearest-neighbor distance if densities are well below saturation. The scheme makes use of an echo sequence in which the first half of a laser pulse excites Rydberg states while the second half returns atoms to the ground state, as in the experiment of Raitzsch et al. [Phys. Rev. Lett. 100 (2008) 013002]. Near to the end of the echo sequence, almost any remaining Rydberg atom is separated from its next-neighbor Rydberg atom by a distance slightly larger than the instantaneous blockade radius half-way through the pulse. These correlations lead to large deviations of the atom counting statistics from a Poissonian distribution. Our results are based on the exact quantum evolution of samples with small numbers of atoms. We finally demonstrate the utility of the omega-expansion for the approximate description of correlation dynamics through an echo sequence.Comment: 8 pages, 6 figure

Magnetfeld Charakterisierung für eine effizientere Dopplerkühlung von ⁹Be⁺-Ionen

As part of this bachelor thesis, an external magnetic coil structure was attached around the Paul trap structure and characterized. The aim was to use the generated magnetic field to align the quantization axis of Be+ ions parallel to the cooling laser in order to make the Doppler cooling of the ions more efficient. For this purpose, the required currents for the coil pairs and the magnetic field-current-ratio in the trap center were determined with COMSOL. The field components of the prevailing earth’s magnetic field were then determined experimentally in order to neutralize its impact on the quantization axis. The influence of the generated magnetic field on the quality of the resonator was also examined, since flux trapping leads to a reduction in the quality. A decrease in the quality of ~ 3.2% with a magnetic field of 271.6 μT was found. Finally, non-linearities were observed in the reflection spectrum of the resonator, which occurred at input powers between 1.3dBm and 2.0dBm and which causes require further investigatio

Temporal rate limiting: Cloud elasticity at a flat fee

Abstract-In the current usage-based pricing scheme offered by most cloud computing providers, customers are charged based on the capacity and the lease time of the resources they capture (bandwidth, number of virtual machines, IOPS rate, etc.). Taking advantage of this pricing scheme, customers can implement auto-scaling purchase policies by leasing (e.g., hourly) necessary amounts of resources to satisfy a desired QoS threshold under their current demand. Auto-scaling yields strict QoS and variable charges. Some customers, however, would be willing to settle for a more relaxed statistical QoS in exchange for a predictable flat charge. In this work we propose Temporal Rate Limiting (TRL), a purchase policy that permits a customer to allocate optimally a specified purchase budget over a predefined period of time. TRL offers the same expected QoS with auto-scaling but at a lower, flat charge. It also outperforms in terms of QoS a naive flat charge policy that splits the available budget uniformly in time. We quantify the benefits of TRL analytically and also deploy TRL on Amazon EC2 and perform a live validation in the context of a "blacklisting" application for Twitter

Trade-Offs in Relative Limb Length among Peruvian Children: Extending the Thrifty Phenotype Hypothesis to Limb Proportions

Background and Methods Both the concept of ‘brain-sparing’ growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The ‘thrifty phenotype’ assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The ‘distal blood flow’ hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447) we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia) and autopod (hand and foot) lengths. Results Highland children (exposed to greater stress) had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements. Discussion The results suggest that functional traits (hand, foot, and head) may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that certain elements of limb growth may be sacrificed under tough conditions to buffer more functional traits

Optimization of electricity trading using linear programming

In the last two decades, the liberalization of the electricity markets have been established in order to increase efficiency, harmonize and reduce electricity prices, make a better use of resources, give customers the right to choose their supplier and provide customers with a better service. This change made the electricity market competitive and introduced several new subjects. In this paper, we study one of these subjects: Electricity Trading Company (ETC) and its daily trading process. We present a linear mathematical model of total daily profit maximization subject to flow constraints. It is assumed that the demand and supply are known and some of them are arranged. Possible transmission capacities are known but also additional capacities can be purchased. All trading, transmission prices and amounts are subject of auctions. First, we present energy trading problem as directed multiple-source and multiple-sink network and then model it using linear programming. Also, we provide one realistic example which is slightly changed in order to save confidentiality of the given data