154 research outputs found
An integrated discrete event simulation and particle swarm optimisation model for optimising efficiency of cancer diagnosis pathways
The National Health Service (NHS) constitution sets out minimum standards for rights of access of patients to NHS services. The ‘Faster Diagnosis Standard’ (FDS) states that 75% of patients should be told whether they have a diagnosis of cancer or not within 28 days of an urgent GP referral. Timely diagnosis and treatment lead to improved outcomes for cancer patients, however, compliance with these standards has recently been challenged, particularly in the context of operational pressures and resource constraints relating to the COVID-19 pandemic. In order to minimise diagnostic delays, the National Physical Laboratory in collaboration with the Royal Free London (RFL) NHS Foundation Trust address this problem by treating it as a formal resource optimisation, aiming to minimise the number of patients who breach the FDS. We use discrete event simulation and particle swarm optimisation to identify areas for improving the efficiency of cancer diagnosis at the RFL. We highlight capacity-demand mismatches in the current cancer diagnosis pathways at the RFL, including imaging and endoscopy investigations. This is due to the volume of patients requiring these investigations to meet the 28-day FDS target. We find that increasing resources in one area alone does not fully solve the problem. By looking at the system as a whole we identify areas for improvement which will have system-wide impact even though individually they do not necessarily seem significant. The outcomes and impact of this project have the potential to make a valuable impact on shaping future hospital activity
The role of vitamers and dietary-based metabolites of vitamin D in prevention of vitamin D deficiency
There is little doubt that vitamin D deficiency across all age groups in Europe is a problem. Low vitamin D status arises due to limited, if any, dermal synthesis during the winter months at latitudes above 40°N, putting increased importance on dietary supply of the vitamin. However, dietary intakes by most populations are low due to the limited supply of vitamin D-rich foods in the food chain. Thus strategies that effectively address this public health issue are urgently required. It has been emphasized and re-emphasized that there are only a limited number of public health strategies available to correct low dietary vitamin D intake: (1) improving intake of naturally occurring vitamin D-rich foods, (2) vitamin D fortification (mandatory or voluntarily) of food, and (3) vitamin D supplementation. Recent evidence suggests that the levels of vitamin D added to food would need to be high so as to ensure dietary requirements are met and health outcomes optimized. In addition, knowledge of the most effective forms of vitamin D to use in some of these preventative approaches is important. There is still uncertainty in relation to the relative efficacy of vitamin D2 versus D3, the two main food derived forms and those used in vitamin D supplements. The major metabolite of vitamin D with biological activity is 1,25(OH)2D; however, this is usually used for pharmacological purposes and is not typically used in normal, healthy people. The other major metabolite, 25(OH)D, which has also been used for pharmacological purposes is present in certain foods such as meat and meat products (particularly offal) as well as eggs. This metabolite may have the potential to boost vitamin D status up to five times more effectively that native vitamin D3 in foods. However, the exact bioactivity of this compound needs to be established
Measures on Banach Manifolds and Supersymmetric Quantum Field Theory
We show how to construct measures on Banach manifolds associated to
supersymmetric quantum field theories. These measures are mathematically
well-defined objects inspired by the formal path integrals appearing in the
physics literature on quantum field theory. We give three concrete examples of
our construction. The first example is a family of measures on a
space of functions on the two-torus, parametrized by a polynomial (the
Wess-Zumino-Landau-Ginzburg model). The second is a family \mu_\cG^{s,t} of
measures on a space \cG of maps from to a Lie group (the
Wess-Zumino-Novikov-Witten model). Finally we study a family
of measures on the product of a space of connection s on the trivial principal
bundle with structure group on a three-dimensional manifold with a
space of \fg-valued three-forms on
We show that these measures are positive, and that the measures
\mu_\cG^{s,t} are Borel probability measures. As an application we show that
formulas arising from expectations in the measures \mu_\cG^{s,1} reproduce
formulas discovered by Frenkel and Zhu in the theory of vertex operator
algebras. We conjecture that a similar computation for the measures
where is a homology three-sphere, will yield the
Casson invariant of Comment: Minor correction
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Proceedings of the Rank Forum on Vitamin D
The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted
concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations
Comparison of mesospheric winds from a high-altitude meteorological analysis system and meteor radar observations during the boreal winters of 2009–2010 and 2012–2013
We present a study of horizontal winds in the mesosphere and lower thermosphere (MLT) during the boreal winters of 2009–2010 and 2012–2013 produced with a new high-altitude numerical weather prediction (NWP) system. This system is based on a modified version of the Navy Global Environmental Model (NAVGEM) with an extended vertical domain up to ∼116 km altitude coupled with a hybrid four-dimensional variational (4DVAR) data assimilation system that assimilates both standard operational meteorological observations in the troposphere and satellite-based observations of temperature, ozone and water vapor in the stratosphere and mesosphere. NAVGEM-based MLT analyzed winds are validated using independent meteor radar wind observations from nine different sites ranging from 69°N–67°S latitude. Time-averaged NAVGEM zonal and meridional wind profiles between 75 and 95 km altitude show good qualitative and quantitative agreement with corresponding meteor radar wind profiles. Wavelet analysis finds that the 3-hourly NAVGEM and 1-hourly radar winds both exhibit semi-diurnal, diurnal, and quasi-diurnal variations whose vertical profiles of amplitude and phase are also in good agreement. Wavelet analysis also reveals common time-frequency behavior in both NAVGEM and radar winds throughout the Northern extratropics around the times of major stratospheric sudden warmings (SSWs) in January 2010 and January 2013, with a reduction in semi-diurnal amplitudes beginning around the time of a mesospheric wind reversal at 60°N that precedes the SSW, followed by an amplification of semi-diurnal amplitudes that peaks 10–14 days following the onset of the mesospheric wind reversal. The initial results presented in this study demonstrate that the wind analyses produced by the high-altitude NAVGEM system accurately capture key features in the observed MLT winds during these two boreal winter periods.</p
Quantifying the direct radiative effect of absorbing aerosols for numerical weather prediction: a case study
We conceptualize aerosol radiative transfer processes arising from the
hypothetical coupling of a global aerosol transport model and a global
numerical weather prediction model by applying the US Naval Research
Laboratory Navy Aerosol Analysis and Prediction System (NAAPS) and the Navy
Global Environmental Model (NAVGEM) meteorological and surface reflectance
fields. A unique experimental design during the 2013 NASA Studies of
Emissions and Atmospheric Composition, Clouds and Climate Coupling by
Regional Surveys (SEAC4RS) field mission allowed for collocated airborne
sampling by the high spectral resolution Lidar (HSRL), the Airborne
Multi-angle SpectroPolarimetric Imager (AirMSPI), up/down shortwave (SW) and infrared (IR) broadband radiometers, as
well as NASA A-Train support from the Moderate Resolution Imaging
Spectroradiometer (MODIS), to attempt direct aerosol forcing closure. The
results demonstrate the sensitivity of modeled fields to aerosol radiative
fluxes and heating rates, specifically in the SW, as induced in this event
from transported smoke and regional urban aerosols. Limitations are
identified with respect to aerosol attribution, vertical distribution, and
the choice of optical and surface polarimetric properties, which are
discussed within the context of their influence on numerical weather
prediction output that is particularly important as the community propels
forward towards inline aerosol modeling within global forecast systems.</p
Rekonstruksi Pengaturan Pajak Penghasilan Atas Usaha Jasa Konstruksi Yang Berasas Keadilan
Peraturan pengenaan Pajak Penghasilan (PPh) yang berlaku saat ini untuk penghasilan
dari usaha jasa konstruksi di Indonesia adalah Peraturan Pemerintah (PP) Nomor 51 Tahun 2008
sebagaimana telah diubah terakhir dengan Peraturan Pemerintah Nomor 40 Tahun 2009.
Peraturan tersebut tidak menyebut aspek keadilan dalam konsideransnya. Penghasilan dari usaha
jasa konstruksi dikenai PPh dengan tarif tersendiri terhadap penghasilan bruto dan bersifat final,
berbeda dengan tarif umum PPh yang dikenakan terhadap penghasilan neto.
Berdasarkan hal tersebut, penulis memfokuskan penelitian disertasi ini untuk menjawab 3
(tiga) rumusan masalah; (1) Mengapa ketentuan Pajak Penghasilan atas usaha jasa konstruksi
sebagaimana diatur dalam PP 51 Tahun 2008 yang telah diubah dengan PP 40 Tahun 2009
tidak mencerminkan asas keadilan? (2) Apa implikasi hukum dari pengaturan Pajak Penghasilan
atas penghasilan dari usaha jasa konstruksi yang tidak mencerminkan asas keadilan?, dan (3)
Bagaimana sebaiknya ketentuan Pajak Penghasilan atas usaha jasa konstruksi diatur agar lebih
mencerminkan asas keadilan? Metode penelitian disertasi ini adalah penelitian hukum normatif
dengan pendekatan perundang-undangan (statute approach), pendekatan sejarah (historical
approach), pendekatan konsep (conceptual approach), dan pendekatan filsafat (philosophical
approach). Sementara itu bahan hukum yang digunakan meliputi bahan hukum primer, sekunder
dan tersier dengan teknik analisis preskriptif analitik (prescriptive analytics).
Hasil penelitian menyimpulkan bahwa ketentuan pengenaan Pajak Penghasilan atas
penghasilan jasa konstruksi yang berlaku saat ini tidak mencerminkan keadilan vertikal (vertical
equity) yang menghendaki bahwa dasar pengenaan PPh yang adil adalah dari penghasilan neto
karena merupakan ukuran yang tepat dalam mencerminkan daya pikul atau kemampuan
membayar (ability to pay). Selain itu pengenaan PPh dengan tarif tersendiri yang berbeda dengan
tarif umum merupakan ketentuan yang diskriminatif karena membeda-bedakan pengenaan PPh
berdasarkan jenis atau sumber penghasilan. Hal ini menyimpang dari prinsip keadilan horizontal
(horizontal equity). Ketentuan yang bersifat final ini berimplikasi pada hilangnya beberapa hak
Wajib Pajak yaitu: hak untuk membayar PPh sesuai dengan kemampuannya, hak untuk
mengurangkan Penghasilan Tidak Kena Pajak (PTKP) bagi Wajib Pajak Orang Pribadi, hak
untuk mengkompensasi kerugian, serta hak untuk memperoleh fasilitas penurunan tarif PPh
sebesar 5% bagi perusahaan terbuka yang memperdagangkan sedikitnya 40% dari jumlah modal
yang disetor di Bursa Efek Indonesia. Selanjutnya ketentuan ini juga menimbulkan adanya
tambahan objek pengenaan PPh Pasal 21 kepada pegawai dalam hal menerima imbalan dalam
bentuk natura dan/atau kenikmatan dari perusahaan jasa konstruksi tempatnya bekerja.
Pertimbangan terbitnya Peraturan Pemerintah tersebut semata-mata hanya kesederhanaan
pengenaan PPh dan kemudahan bagi Wajib Pajak, tidak menyebut sama sekali aspek keadilan.
Penulis menyarankan agar bagi Wajib Pajak pengusaha jasa konstruksi berbentuk badan
yang berdasarkan ketentuan diwajibkan menyelenggarakan pembukuan serta bagi pengusaha jasa
konstruksi perorangan yang tidak diwajibkan tetapi mampu menyelenggarakan pembukuan,
diberlakukan ketentuan pengenaan PPh dari penghasilan neto dengan tarif umum PPh
sebagaimana diatur dalam Pasal 17 ayat (1) huruf (a), Pasal 17 ayat (2a) atau Pasal 31E UU PPh
2008 dan tidak bersifat final. Sementara itu Wajib Pajak yang dikenai PPh bersifat final dengan
tarif tersendiri sesuai ketentuan Pasal 4 ayat (2) UU PPh 2008 serta dasar pengenaannya dari
penghasilan bruto seyogianya hanya diberlakukan terhadap Wajib Pajak pengusaha jasa
konstruksi orang pribadi yang peredaran brutonya tidak lebih dari Rp.4.800.000.000 dalam 1
(satu) tahun pajak dan belum mampu menyelenggarakan pembukuan. Namun demikian
pengenaan PPh final tersebut harus dibatasi hingga jangka waktu tertentu sebagai masa
pembelajaran untuk dapat menyelenggarakan pembukuan sebelum dikenai PPh dengan tarif
umum. Tarifnya disetarakan dengan tarif PPh final yang berlaku untuk Wajib Pajak Usaha
Mikro, Kecil dan Menengah (UMKM). Selanjutnya penulis juga merekomendasikan agar
Pemerintah dan DPR mengubah ketentuan Pasal 4 ayat (2) UU PPh 2008 yang memberikan
kewenangan kepada pemerintah untuk mengenakan penghasilan tertentu dengan pajak yang
bersifat final dengan mempertimbangkan bahwa pengenaan PPh yang bersifat final atas
penghasilan dari usaha jasa konstruksi seyogianya diberlakukan hanya bagi Orang Pribadi yang
belum sanggup menyelenggarakan pembukuan sampai dengan jangka waktu tertentu sebagai
masa transisi pembelajaran pembukuan. Selain itu Pemerintah hendaknya menghapus ketentuan
yang membeda-bedakan tarif PPh berdasarkan pemilikan sertifikasi dan kualifikasi usaha jasa
konstruksi
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