Binary Beetle Antennae Search Algorithm for Tangency Portfolio Diversification

The tangency portfolio, also known as the market portfolio, is the most efficient portfolio and arises from the intercept point of the Capital Market Line (CML) and the efficient frontier. In this paper, a binary optimal tangency portfolio under cardinality constraint (BOTPCC) problem is defined and studied as a nonlinear programming (NLP) problem. Because such NLP problems are widely approached by heuristic, a binary beetle antennae search algorithm is employed to provide a solution to the BTPSCC problem. Our method proved to be a magnificent substitute to other evolutionary algorithms in real-world datasets, based on numerical applications and computer simulations

Optimal Portfolio Insurance under Nonlinear Transaction Costs

The minimization of the costs related to portfolio insurance is a very important investment strategy. In this article, by adding the transaction costs to the classical minimum cost portfolio insurance (MCPI) problem, we define and study the MCPI under transaction costs (MCPITC) problem as a nonlinear programming (NLP) problem. In this way, the MCPI problem becomes more realistic. Since such NLP problems are commonly solved by heuristics, we use the Beetle Antennae Search (BAS) algorithm to provide a solution to the MCPITC problem. Numerical experiments and computer simulations in real-world data sets confirm that our approach is an excellent alternative to other evolutionary computation algorithms

From fundamental science to product : a bottom-up approach to sunscreen development

Despite the pivotal role of ultraviolet (UV) radiation in sustaining life on Earth, overexposure to this type of radiation can have catastrophic effects, such as skin cancer. Sunscreens, the most common form of artificial protection against such harmful effects, absorb UV radiation before it reaches vulnerable s kin cells. Absorption of UV radiation prompts ultrafast molecular events in sunscreen molecules which, ideally, would allow for fast and safe dissipation of the excess energy. However, our knowledge of these mechanisms remains limited. In this article, we will review recent advances in the field of ultrafast photodynamics (light induced molecular processes occurring within femtoseconds, fs, 10 - 15 s to picoseconds, ps, 10 - 12 s) of sunscreens. We follow a bottom - up approach to common sunscreen active ingredients, analysing any emerging trends from the current literature on the subject. Moreover, we will identify the main questions that remain unanswered, pinpoint some of the main challenges and finally comment on the outlook of this exciting field of research

Photophysics of sunscreen molecules in the gas phase : a stepwise approach towards understanding and developing next-generation sunscreens

The relationship between exposure to ultraviolet (UV) radiation and skin cancer urges the need for extra photoprotection, which is presently provided by widespread commercially available sunscreen lotions. Apart from having a large absorption cross section in the UVA and UVB regions of the electromagnetic spectrum, the chemical absorbers in these photoprotective products should also be able to dissipate the excess energy in a safe way, i.e. without releasing photoproducts or inducing any further, harmful, photochemistry. While sunscreens are tested for both their photoprotective capability and dermatological compatibility, phenomena occurring at the molecular level upon absorption of UV radiation are largely overlooked. To date, there is only a limited amount of information regarding the photochemistry and photophysics of these sunscreen molecules. However, a thorough understanding of the intrinsic mechanisms by which popular sunscreen molecular constituents dissipate excess energy has the potential to aid in the design of more efficient, safer sunscreens. In this review, we explore the potential of using gas-phase frequency- and time-resolved spectroscopies in an effort to better understand the photoinduced excited-state dynamics, or photodynamics, of sunscreen molecules. Complementary computational studies are also briefly discussed. Finally, the future outlook of expanding these gas-phase studies into the solution phase is considered

Predicting Potential Aluminum Contamination of Surface and Ground Waters from Acid Sulfate Enriched Drainages Emanating from Low Neutralization Capacity Watersheds

The composition of soil solutions and surface waters emanating from unreclaimed, or partially reclaimed, strip-mined watersheds with low buffering capacity in Kentucky were compared with soil solution compositions of unaffected strata in the watershed. The data suggest that almost 20 years after mining, most soil solutions and surface waters of the disturbed areas still contain high levels of dissolved Al, controlled primarily by the solubilities of a jurbanite-like mineral (upper limit) and alunite (lower limit). Soluble Al in solutions of undisturbed areas was consistent with the solubility of kaolinite or gibbsite. The absence of jurbanite x-ray diffraction peaks suggested the presence of an amorphous mineral or one stoichiometrically similar to jurbanite. Despite greater residence times for soil solutions as compared to surface waters, their compositional differences were insignificant. The control of soluble AL by basic aluminum sulfate minerals was not affected by the variable mineralogical and textural composition of soil and geologic strata in the watershed. Apparently, this is the result of low buffering capacity. At pH 4, pH and sulfate activities can be used to accurately predict the levels of soluble Al3+ in surface and ground waters of the watersheds. Similar predictions from pH and SO2-/4 activities can also be made for dissolved Fe3+ levels, supporting the stoichiometry but a much higher solubility than that of jarosite

Predicting Potential Aluminum Contamination of Surface and Ground Waters from Acid Sulfate Enriched Drainages Emanating from Low Neutralization Capacity Watersheds

The composition of soil solutions and surface waters emanating from unreclaimed, or partially reclaimed, strip-mined watersheds with low buffering capacity in Kentucky were compared with soil solution compositions of unaffected strata in the watershed. The data suggests that almost 20 years after mining, most soil solutions and surface waters of the disturbed areas still contain high levels of undissolved Al, controlled primarily by the solubilities of a jurbanite-like material (upper limit) and alunite (lower limit)

Torsional motion of the chromophore catechol following the absorption of ultraviolet light

The ability to probe energy flow in molecules, following the absorption of ultraviolet light, is crucial to unraveling photophysical phenomena. Here we excite a coherent superposition of vibrational states in the first excited electronic state (S1) in catechol, resulting in a vibrational wave packet. The observed quantum beats, assigned to superpositions of the low-frequency, and strongly mixed, O–H torsional mode τ2, elegantly demonstrate how changes in geometry upon photoionization from the S1 state to the ground state of the cation (D0) enables one to probe energy flow at the very early stages of photoexcitation in this biological chromophore

Muscle activation capacity: effects of method, stimuli number and joint angle

To assess the sensitivity of existing measurement methods for muscle activation capacity to potential errors introduced by a) evoking inadequate force by stimulation and b) neglecting differences in series elasticity between conditions, the effect of different number of stimuli and joint angle on the interpolation twitch interpolation technique [ITT = (1- superimposed stimulus torque / resting stimulus torque) x 100] and central activation ratio (CAR = maximal voluntary contraction torque / maximal voluntary contraction torque + superimposed stimulus torque) was examined. Ten subjects performed knee extension maximal voluntary contractions at 30 and 90o knee flexion angles (0o is full knee extension). Singlets, doublets, quadruplets and octuplets of supramaximal intensity were applied via percutaneous quadriceps muscle stimulation at rest and during the plateau phase of the contraction. A mixed-design 2 x 2 x 4 repeated factorial ANOVA was used to examine for differences in activation capacity between methods, knee joint angles and stimuli number, and simple effects tests were used for post hoc analysis where appropriate. Joint angle had a significant effect (P 0.05). It is, therefore, suggested that in the quantification of voluntary drive during contraction with the ITT and CAR methods, consideration be given not only to the number of stimuli applied but also to the effect of series elasticity due to joint angle differences, since these factors may affect differently the outcome of the calculation, depending on the approach followed

Potential Impact of the Financial Crisis on Outpatient Hospital Visits due to Otorhinolaryngologic Disorders in Crete, Greece

The public health effect of financial crises has been emphasized in previous studies. In addition, a series of otorhinolaryngologic disorders and manifestations has been related to psychological factors in the literature. Such conditions include temporomandibular joint disorders, laryngopharyngeal reflux, chronic tinnitus, and vertigo. Focusing on the outpatient database records of a large hospital in Crete, Greece, the objective of this retrospective study was to explore possible occurrence variations within the prementioned otorhinolaryngologic morbidity which may be potentially attributed to increased levels of socioeconomic stress. Results revealed that although the total number of visits between two periods - before and after the beginning of the financial crisis in Greece - was comparable, a significant increase in the diagnosis of two disorders, namely vertigo and tinnitus was found. In addition, a trend toward increased rate of diagnosis for reflux and temporomandibular joint disorders was noted. Potential implications of these findings are discussed. In conclusion, health care providers in this as well as in other countries facing similar socio-economic conditions should be aware of potential changes in the epidemiologic figures regarding specific medical conditions