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Background: Humans are very susceptible to the poison of insects. Some animals can produce substances that cause allergic reactions in humans. In these conditions, the immune system responds through mechanisms that provoke a state of defense in the affected person to fight against the aggression. In many cases, this defense is very strong to the organism itself.Methods: The topic: “hypersensitivity due to stings of insects (bees and wasps)” was reviewed by keywords of articles included in the Google Scholar, Web of Science, and PubMed databases. The articles were selected by their relevance. Recently published articles in peer-reviewed journals were included, conducting a detailed review of all contents.Results: The review indicated that the hypersensitivity mechanisms produced by bee and wasp stings are mainly mediated by IgE’s antibodies. In addition, the crucial importance of a rapid response to the first symptoms of hypersensitivity to prevent the venom severe symptoms leading to the patient´s death is emphasized.Conclusions: The current knowledge of hypersensitivity reactions in individuals susceptible to bee and wasp stings was reviewed and summarized, revealing that IgE-mediated allergic reactions are the main mechanism. Adequate treatment after the inoculation of the poison is decisive in the patient´s recovery.

Background: Humans are very susceptible to the poison of insects. Some animals can produce substances that cause allergic reactions in humans. In these conditions, the immune system responds through mechanisms that provoke a state of defense in the affected person to fight against the aggression. In many cases, this defense is very strong to the organism itself. Methods: The topic: "hypersensitivity due to stings of insects (bees and wasps)" was reviewed by keywords of articles included in the Google Scholar, Web of Science, and PubMed databases. The articles were selected by their relevance. Recently published articles in peer-reviewed journals were included, conducting a detailed review of all contents. Results: The review indicated that the hypersensitivity mechanisms produced by bee and wasp stings are mainly mediated by IgE's antibodies. In addition, the crucial importance of a rapid response to the first symptoms of hypersensitivity to prevent the venom severe symptoms leading to the patient's death is emphasized. Conclusions: The current knowledge of hypersensitivity reactions in individuals susceptible to bee and wasp stings was reviewed and summarized, revealing that IgE-mediated allergic reactions are the main mechanism. Adequate treatment after the inoculation of the poison is decisive in the patient's recovery. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine associations between vitamin E status and cognitive performance in elderly people. The study subjects were a group of 34 men and 86 women, aged 65-91 y, who were free of significant cognitive impairment. Dietary intake was monitored using a 'weighed food record' for 5 consecutive days including a Sunday. Serum levels of [alpha]-tocopherol and cholesterol were determined by HPLC and colorimetric methods, respectively. The cognitive capacity of subjects was tested using the Pfeiffer's Mental Status Questionnaire (PMSQ). Subjects with vitamin E intakes lower than 50% of those recommended had higher PMSQ scores, demonstrating a greater number of errors in comparison to participants with a greater intake of the vitamin (0.91 [+ or -] 1.22 vs. 0.47 [+ or -] 0.60, respectively, P < 0.05). Subjects who made no errors in the PMSQ test had significantly higher serum [alpha]-tocopherol concentrations (19.7 [+ or -] 8.6 [micro]mol/L in men and 20.0 [+ or -] 8.4 [micro]mol/L in women) and [alpha]-tocopherol/cholesterol ratios (3.5 [+ or -] 2.0 [micro]mol/mmol in men 2.9 [+ or -] 1.4 [micro]mol/mmol in women) compared with those who made errors ([alpha]-tocopherol 15.1 [+ or -] 5.6 [micro]mol/L in men and 14.9 [+ or -] 6.1 [micro]mol/L in women; [alpha]-tocopherol/cholesterol ratio 2.4 [+ or -] 0.8 and 2.3 [+ or -] 1.3 [micro]mol/mmol in men and women, respectively). This study shows there to be a relationship between vitamin E status and cognitive function, and that vitamin E status could be improved in this population of elderly individuals. KEY WORDS: * vitamin E * elderly people * [alpha]-tocopherol * intake * cognitive function

An optical implementation of the fractional Fourier transform (FRT) with broadband illumination is proposed by use of a single imaging element, namely, a blazed diffractive lens. The setup displays an achromatized version of the FRT of order P of any two-dimensional input function. This fractional order can be tuned continuously by shifting of the input along the optical axis. Our compact and flexible configuration is tested with a chirplike input signal, and the good experimental results obtained support the theory.

The strong chromatic distortion associated with diffractive optical elements is fully exploited to achieve an achromatic optical Fourier transformation under broadband point-source illumination by means of an air-spaced diffractive lens doublet. An analysis of the system is carried out by use of the Fresnel diffraction theory, and the residual secondary spectrum (both axial and transversal) is evaluated. We recognize that the proposed optical architecture allows us to tune the scale factor of the achromatic Fraunhofer diffraction pattern of the input by simply moving the diffracting screen along the optical axis of the system. The performance of our proposed optical setup is verified by several laboratory results.

A flexible array illuminator, comprising only two conventional optical elements, with a variable density of bright white-light spots is presented. The key to our method is to obtain with a single diffractive lens an achromatic version of different fractional Talbot images, produced by free-space propagation, of the amplitude distribution at the back focal plane of a periodic refractive microlens array under a broadband point-source illumination. Some experimental results of our optical procedure are also shown.

We propose a new method for the computation of the tristimuli values that correspond to the impulse response along the optical axis provided by an imaging optical system working under polychromatic illumination. We show that all the monochromatic irradiance distributions needed for this calculation can be obtained from the Wigner distribution function associated with a certain version of the pupil function of the system. The use of this single phase-space representation allows us to obtain the above merit function for aberrated systems with longitudinal chromatic aberration and primary spherical aberration. Some numerical examples are given to verify the accuracy of our proposal.

A new optical implementation of the Radon-Wigner display for one-dimensional objects is presented, making use of the fractional Fourier transform approach. The proposed setup makes use of only two conventional refractive elements: a cylindrical lens and a varifocal lens. Although the exact magnifications cannot be achieved simultaneously for all the fractional transforms, an optimum design can be obtained through balancing the conflicting magnification requirements. Experimental results are obtained with a commercially available progressive addition lens. For comparison, computer simulations are also provided. Key words: Optical information processing, fractional Fourier transform, Wigner distribution function, Radon-Wigner transform, optical wave propagation.

The deterioration of functional and mental capacity is one of the major problems of the elderly. This deterioration may be caused or worsened by folate deficiency. The aim of this investigation was to analyze the relationship between mental and functional capacities and folate status in a group of 177 elderly Spanish people. Folate deficiency is common in the Spanish population. In this study, 48.6% of the elderly subjects had folate intakes below recommended values (200 [[micro]gram]/day), 34.9% had serum concentrations [less than] 14 nmol/L and 6.6% had [less than]360 nmol/L erythrocyte folate. Subjects took part in a series of tests: Katz' scale of activities of daily living, Lawton's scale of instrumental activities of daily living, Pfeiffer's mental status questionnaire, Folstein's Mini-Mental State Test and the Geriatric Depression scale of Yesavage. The results for Lawton's scale of instrumental activities of daily living were significantly better (indicating greater independence and capacity) when folate intake and serum or erythrocyte folate concentrations were adequate (i.e., folate intake no less than recommended, [greater than or equal to]14 nmol/L serum folate or [greater than or equal to]360 nmol/L erythrocyte folate). Subjects with adequate Mini-Mental State Exam results ([greater than or equal to]28 points) had serum and erythrocyte folate concentrations significantly higher than those with less adequate results ([less than]28 points). Thus, there is evidence to suggest that the folate status of the elderly should be monitored and, if possible, improved. J. Nutr. 126: 1992-1999, 1996. INDEXING KEY WORDS: functional capacity; psychic deterioration; elderly; folate deficiency; humans

The intake of fruits, fish and non-alcoholic beverages is higher among physically active Spanish elderly from high socioeconomic group, than among other Spanish and European sedentary old people. About 50% of the group consumes lesser vitamins, zinc and magnesium than recommended intake levels. There is an increase in the consumption of meat products, niacin and thiamine with increase in age. Increase in body mass index leads to a decrease in fruits, fibers and vitamins intake. Despite under reporting and overreporting, the group is at a high risk of nutrient deficiency.

We show that, at any Fresnel number, a suitable one-dimensional Fourier transform relates the complex-amplitude distribution along the optical axis with the zero-order circular harmonic of the amplitude transmittance of a two-dimensional diffracting screen. First, our general result is applied to recognize that any rationally nonsymmetric screen generates an axial-irradiance distribution that exhibits focal shift. In this way we identify a wide set of two-dimensional screens that produce the same focal shift as that produced by the clear circular aperture. Second, we identify several apodizers for shaping the axial-amplitude distribution. We discuss some examples for achieving high-precision focusing, axial hyperresolution, or high focal depth.

A spatial filtering technique is proposed to sharpen the correlation peak for a joint transform correlator (JTC) by using the inverse reference power spectrum. Ways of handling the pole problems are discussed under various noise conditions. The minimum mean-square-error method is used to locate the optimum bias value and to estimate threshold level as applied to eradicate the poles. Applications to multitarget recognition and spectral fringe binarization are also studied. Computer-simulated results show that the compensated JTC performs better than the conventional JTC.