2,080 research outputs found
Reduction of the Two Body Problem in N=2 Chern Simons Supergravity
By an extension of the methods used for the reduction of the two body problem
in 2+1 dimensional gravity, we show that the two body problem in N=2 Chern
Simons supergravity can be reduced exactly to an equivalent on body formalism.
We give exact expressions for the invariants of the reduced one body problem.Comment: 9 pages, LaTe
Product Integral Representations of Wilson Lines and Wilson Loops, and Non-Abelian Stokes Theorem
We make use of product integrals to provide an unambiguous mathematical
representation of Wilson line and Wilson loop operators. Then, drawing upon
various properties of product integrals, we discuss such properties of these
operators as approximating them with partial sums, their convergence, and their
behavior under gauge transformations. We also obtain a surface product integral
representation for the Wilson loop operator. The result can be interpreted as
the non-abelian version of Stokes theorem.Comment: 20 pages, LaTe
Deterrence policies and asylum seekers: the case of Australia
The basic tenets of the international refugee protection regime, set out in the UN\u27s 1951 Convention and the 1967 Protocol, grant individuals the right to seek asylum, but do not provide for laws obliging signatory states to grant asylum. This inherent paradox allows signatory states ongoing manoeuvre to prevent would-be asylum seekers from accessing protection in their territories. To this end, countries of the global north have designed and implemented a range of measures aimed at deterring onshore asylum seekers - privileging border control over refugee protection. This paper examines the effectiveness of deterrence measures taken by Australia. It argues that deterrence measures and attendant political rhetoric are not only contrary to international humanitarian obligations, but obscure empirically grounded understandings of forced migration as a complex social phenomenon, and as such are problematic in terms of meeting their publicly stated objectives of stopping on-shore asylum seeking in the long term
Dimensionless Coupling of Superstrings to Supersymmetric Gauge Theories and Scale Invariant Superstring Actions
We construct new superstring actions which are distinguished from standard
superstrings by being space-time scale invariant. Like standard superstrings,
they are also reparametrization invariant, space-time supersymmetric, and
invariant under local scale transformations of the world sheet. We discuss
scenarios in which these actions could play a significant role, in particular
one which involves their coupling to supersymmetric gauge theories.Comment: 9 pages, LaTe
Analyzing the relationship between social and professional identity characteristics of the audit committee and the steering system on the quality of financial reporting: a legal oriented artificial approach
The purpose of this study was to analyze the impact of the social and professional identity of the members of the audit committee and the characteristics of the governance system on the financial reporting quality. The modified Jones model was used to express the financial reporting quality. Given that part of the data was obtained through a questionnaire and another part by using financial statements. The research period was 2019 and the sample size was 79 companies listed in Tehran Stock Exchange. To test the research hypotheses, the method of decision making artificial intelligence method and MATLAB software were used. The results of the section of the governance system features indicate the effect of the dual role of the CEO and the ratio of institutional owners on the financial reporting quality. It can be stated that corporate governance mechanisms can reduce opportunistic behavior; they can improve the quality of information by reducing the cost of representation. Also, the results of the audit committee's benchmarks indicate the impact of the audit committee's social identity and the number of employees in internal accounting section on the financial reporting quality, which suggests that effective audit committees, as a determining factor in the financial reporting process, increase the credibility of audited financial statements. In this study, for the first time, the impact of audit committee social identity along with other characteristics of governance system on the quality of financial reporting was analyzed by artificial intelligence
Effect of urban albedo surfaces on thermal comfort
Thermal comfort was and remains a major concern of the designers, makers, planners, climatologists and others, seeking at all costs to ensure the well-being, good health and comfort of citizens in both outdoor and indoor areas. They have addressed this issue in order to identify the main causes that generate the warming of urban areas and therefore contribute to the degradation of the exterior and interior thermal comfort of the inhabitants. It turns out that the reflectivity of materials known as the albedo, plays a leading role in this degradation. A numerical study was carried out to assess the thermal comfort of citizens by applying reflective materials for roofs, facades and floor. The results show that the reflective light paints help in moderating the microclimate, contrariwise, they participate in the degradation of thermal comfort.Keywords: Reflectivity; Materials; Envi-met; Rayman; Degradatio
Evaluation of pdx-1 gene expression in insulin producing cells, derived from embryonal carcinoma stem cells
زمینه و هدف: درک عملکرد سلول های بتا در سطح مولکولی به احتمال زیاد توسعه تکنیک های تولید سلول های بتا را تسهیل می کند. این مطالعه با هدف بررسی بیان ژن هومئوباکس دئودنال 1 (pdx-1) در سلولهای تمایز یافته طراحی و اجرا شد. روش بررسی: این مطالعه بنیادی-کاربردی بر روی تمایز سلولهای بنیادی به سلولهای انسولینساز انجام گرفت. محیط ثانویه حاصل از کشت پانکراس نوزاد یک هفتهای موش برای تمایز سلولهای P19 استفاده شد. اجسام شبه جنینی (EBs) با کشت معلق 24 ساعته سلولهای P19 تشکیل شدند. برای القای تمایز، غلظتهای متفاوت محیط ثانویه (25، 50، 75 و 100) به محیط کشت اضافه شد. جهت شناسایی سلولهای تمایز یافته مشتق از EBs در شرایط آزمایشــگاهی از رنگ آمیزی دیتیزون استفاده شد. تولید انسولین-پروانسولین و رسپتور بتای انسولین در این سلول ها به روش ایمنوفلورسنس تعیین و بیان ژن pdx-1 به وسیله واکنش زنجیره پلیمراز-رونویسی معکوس ارزیابی شد. داده ها با استفاده از آزمون های آماری آنالیز واریانس یک طرفه و دانکن تجزیه و تحلیل شدند. یافتهها: پس از هفت روز القا، دستجات سلولی تمایز یافته ظاهر شدند. اوج پاسخگویی تمایزی مربوط به غلظت 50 از محیط ثانویه بود. بیان ژن pdx-1 در دستجات سلولی تمایز یافته مشاهده شد. بیان نشانگرهای انسولین-پروانسولین و رسپتور بتا در سلولهای تمایز یافته به روش ایمنوفلورسنس اثبات شد. نتیجهگیری: محیط ثانویه پانکراس باعث تمایز سلولهای P19به سلولهای انسولین ساز شد، لذا نتایج این مطالعه می تواند تولید سلول های بتا را از سلول های بنیادی تسهیل نماید
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