Variation in annual volume at a university hospital does not predict mortality for pancreatic resections.

Annual volume of pancreatic resections has been shown to affect mortality rates, prompting recommendations to regionalize these procedures to high-volume hospitals. Implementation has been difficult, given the paucity of high-volume centers and the logistical hardships facing patients. Some studies have shown that low-volume hospitals achieve good outcomes as well, suggesting that other factors are involved. We sought to determine whether variations in annual volume affected patient outcomes in 511 patients who underwent pancreatic resections at the University of California, San Francisco between 1990 and 2005. We compared postoperative mortality and complication rates between low, medium, or high volume years, designated by the number of resections performed, adjusting for patient characteristics. Postoperative mortality rates did not differ between high volume years and medium/low volume years. As annual hospital volume of pancreatic resections may not predict outcome, identification of actual predictive factors may allow low-volume centers to achieve excellent outcomes

Electronic Properties of Strained Si/Ge Core-Shell Nanowires

We investigated the electronic properties of strained Si/Ge core-shell nanowires along the [110] direction using first principles calculations based on density-functional theory. The diameter of the studied core-shell wire is up to 5 nm. We found the band gap of the core-shell wire is smaller than that of both pure Si and Ge wires with the same diameter. This reduced band gap is ascribed to the intrinsic strain between Ge and Si layers, which partially counters the quantum confinement effect. The external strain is further applied to the nanowires for tuning the band structure and band gap. By applying sufficient tensile strain, we found the band gap of Si-core/Ge-shell nanowire with diameter larger than ~3 nm experiences a transition from direct to indirect gap.Comment: 4 figure

Challenges and Opportunities to Improve Tuberculosis Screening Among Immigrant Plantation Workers in Sabah, Malaysia

Tuberculosis (TB) among immigrants has substantial contribution to the TB epidemiology in Sabah. This study aimed to determine the yield of screening for TB disease among immigrant plantation workers in Sabah, Malaysia. This was a prospective cohort study involving 482 legal immigrant workers aged 18 years and above, consented and available at study sites during the study period. Workers with previous history of TB or currently on TB treatment were excluded from participation. Symptom based questionnaire was administered along with both chest radiograph and sputum samples collection for symptomatics participants. Out of 482 plantation workers creened, there was no case of active TB detected among the 44 (9.1%) symptomatics participants. Finding of low TB yield in this study was rather unexpected but this indicates the real challenges for the local health authority to come out with more cost effective screening programs, including reducing stigma, in active TB screening among migrant population

Assessing the readiness of contractors in implementing low carbon construction in Penang

Global warming or climate change is becoming the main concerns of humanity as it leads to an increase in Earth’s temperature and rise in the oceans’ level which is due to the increase of greenhouse gasses in the atmosphere. Greenhouse gasses consists of water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N20), tropospheric ozone (O3) and chlorofluorocarbons (CFCs). Among the gasses, CO2 is the highest and easiest gas to measure as it is emitted from human economic activities with construction industry one of the major contributors of carbon emissions. Low carbon construction is the reduction of carbon emissions from the construction activities during construction process. For the implementation of low carbon construction in our construction industry, the contractors need to be ready and have knowledge to adopt low carbon construction industry. The purpose of this research is to determine the level of contractors’ knowledge towards low carbon construction, determining the level of readiness towards low carbon construction and proposing a checklist for the contractors towards low carbon construction in Penang. This research employed questionnaire survey to analyse the level of knowledge and readiness of the contractors on low carbon construction. As a conclusion, the implementation of low carbon practices by the contractors in Penang is good, therefore established that G7 contractors implement low carbon practices throughout their construction. However, the results and findings indicated that the average mean score on the level of readiness of contractors towards low carbon construction is 3.59. The result was perceived as moderate. Therefore, it shows that the contractors are in a moderate readiness to implement low carbon construction fully in their construction projects. A checklist was established by summarizing the highest low carbon activities from each category which were sustainable site planning and management, materials and resources, waste management, water efficiency and energy efficiency, and was perceived as good. Keywords: Climate change, greenhouse gases, carbon emission, low carbon construction, contractors’ readiness

Hanbury Brown and Twiss Interferometry with Twisted Light

The rich physics exhibited by random optical wave fields permitted Hanbury Brown and Twiss to unveil fundamental aspects of light. Furthermore, it has been recognized that optical vortices are ubiquitous in random light and that the phase distribution around these optical singularities inprints a spectrum of orbital angular momentum onto a light field. We demonstrate that random fluctuations of light give rise to the formation of correlations in the orbital angular momentum components and angular positions of pseudothermal light. The presence of these correlations is manisfested through distinct interference structures in the orbital angular momentum-mode distribution of random light. These novel forms of interference correspond to the azimuthal analog of the Hanbury Brown and Twiss effect. This family of effects can be of fundamental importance in applications where entanglement is not required and where correlations in angular position and orbital angular momentum suffice. We also suggest that the azimuthal Hanbury Brown and Twiss effect can be useful in the exploration of novel phenomena in other branches of physics and astrophysics.Comment: Science Advance

Scaling in many-body systems and proton structure function

The observation of scaling in processes in which a weakly interacting probe delivers large momentum ${\bf q}$ to a many-body system simply reflects the dominance of incoherent scattering off target constituents. While a suitably defined scaling function may provide rich information on the internal dynamics of the target, in general its extraction from the measured cross section requires careful consideration of the nature of the interaction driving the scattering process. The analysis of deep inelastic electron-proton scattering in the target rest frame within standard many-body theory naturally leads to the emergence of a scaling function that, unlike the commonly used structure functions $F_1$ and $F_2$, can be directly identified with the intrinsic proton response.Comment: 11 pages, 4 figures. Proceedings of the 11th Conference on Recent Progress in Many-Body Theories, Manchester, UK, July 9-13 200

Quantum Hilbert hotel

In 1924 David Hilbert conceived a paradoxical tale involving a hotel with an infinite number of rooms to illustrate some aspects of the mathematical notion of “infinity.” In continuous-variable quantum mechanics we routinely make use of infinite state spaces: here we show that such a theoretical apparatus can accommodate an analog of Hilbert’s hotel paradox. We devise a protocol that, mimicking what happens to the guests of the hotel, maps the amplitudes of an infinite eigenbasis to twice their original quantum number in a coherent and deterministic manner, producing infinitely many unoccupied levels in the process. We demonstrate the feasibility of the protocol by experimentally realizing it on the orbital angular momentum of a paraxial field. This new non-Gaussian operation may be exploited, for example, for enhancing the sensitivity of NOON states, for increasing the capacity of a channel, or for multiplexing multiple channels into a single one

Strain Modulated Electronic Properties of Ge Nanowires - A First Principles Study

We used density-functional theory based first principles simulations to study the effects of uniaxial strain and quantum confinement on the electronic properties of germanium nanowires along the [110] direction, such as the energy gap and the effective masses of the electron and hole. The diameters of the nanowires being studied are up to 50 {\AA}. As shown in our calculations, the Ge [110] nanowires possess a direct band gap, in contrast to the nature of an indirect band gap in bulk. We discovered that the band gap and the effective masses of charge carries can be modulated by applying uniaxial strain to the nanowires. These strain modulations are size-dependent. For a smaller wire (~ 12 {\AA}), the band gap is almost a linear function of strain; compressive strain increases the gap while tensile strain reduces the gap. For a larger wire (20 {\AA} - 50 {\AA}), the variation of the band gap with respect to strain shows nearly parabolic behavior: compressive strain beyond -1% also reduces the gap. In addition, our studies showed that strain affects effective masses of the electron and hole very differently. The effective mass of the hole increases with a tensile strain while the effective mass of the electron increases with a compressive strain. Our results suggested both strain and size can be used to tune the band structures of nanowires, which may help in design of future nano-electronic devices. We also discussed our results by applying the tight-binding model.Comment: 1 table, 8 figure

The Debt-Equity Ratio Choice: Risk Sharing Instruments, a Viable Alternative

Evidence has been documented in the literature that the interest based debt financing system is experiencing continuous discomfort. The outcome of the 2008 global financial crisis has further create fresh vigor to the assertion. Also, these authors have submitted that debt and leveraging are the two major causes of financial instability in the present system. This paper claims that the existence of the interest-based debt regime is becoming less acceptable, as excessive debt can affect the whole economic system, even in a developed country like United States. From an economic viewpoint, therefore, by banning interest rate-based contracts and decreeing exchange contracts, Islamic financeinspires risk sharing and prohibits risk transfer, risk shedding, and risk shifting. The paper proposes risk sharing based Islamic financing as a suitable alternative to the interest based debt financing. This study concludes that risk-sharing finance has several benefits, especially its potential to minimize, if not circumvent, the debt prompted financial crises that have beset the world.