The influence of season, photoperiod, and pineal melatonin on immune function.

In addition to the well-documented seasonal cycles of mating and birth, there are also significant seasonal cycles of illness and death among many animal populations. Challenging winter conditions (i.e., low ambient temperature and decreased food availability) can directly induce death via hypothermia, starvation, or shock. Coping with these challenges can also indirectly increase morbidity and mortality by increasing glucocorticoid secretion, which can compromise immune function. Many environmental challenges are recurrent and thus predictable; animals could enhance survival, and presumably increase fitness, if they could anticipate immunologically challenging conditions in order to cope with these seasonal threats to health. The annual cycle of changing photoperiod provides an accurate indicator of time of year and thus allows immunological adjustments prior to the deterioration of conditions. Pineal melatonin codes day length information. Short day lengths enhance several aspects of immune function in laboratory studies, and melatonin appears to mediate many of the enhanced immunological effects of photoperiod. Generally, field studies report compromised immune function during the short days of autumn and winter. The conflict between laboratory and field data is addressed with a multifactor approach. The evidence for seasonal fluctuations in lymphatic tissue size and structure, as well as immune function and disease processes, is reviewed. The role of pineal melatonin and the hormones regulated by melatonin is discussed from an evolutionary and adaptive functional perspective. Finally, the clinically significance of seasonal fluctuations in immune function is presented. Taken together, it appears that seasonal fluctuations in immune parameters, mediated by melatonin, could have profound effects on the etiology and progression of diseases in humans and nonhuman animals. An adaptive functional perspective is critical to gain insights into the interaction among melatonin, immune function, and disease processes

Rancang Bangun Mesin Pemintal Agel

Industri kerajinan agel telah ada dan berkembang di beberapa wilayah di Indonesia. Sentra industri tali (tampar) agel berada di Desa Kapasan, Kecamatan Nguling, Kabupaten Pasuruan, sedangkan sentra industri kerajinan agel berada di Kecamatan Sentolo, Kabupaten Kulonprogo. Industri ini menghasilkan berbagai macam produk kerajinan bernilai ekonomi tinggi seperti; tas, topi, furnitur, noken dan masih banyak lagi produk kerajinan lainnya. Permasalahan yang dihadapi industri kerajinan agel adalah proses produksi dilakukan secara manual dengan keterbatasan pada kapasitas produksi dan ketidakstabilan kualitas produk bahan baku tali agel. Tujuan penelitian ini adalah untuk membuat prototype mesin pintal agel yang dapat mempersingkat tahapan proses dan meningkatkan kapasitas produksi industri kerajinan agel. Metode yang digunakan yaitu pengumpulan data melalui survey literatur dan lapangan, perancangan desain, penyiapan bahan dan alat, pembuatan mesin, uji coba dengan variabel kecepatan putaran dan panjang agel, analisa dan pembahasan hasil uji coba. Penelitian ini menghasilkan satu unit mesin pemintal agel dengan spesifikasi panjang: 110 cm, lebar: 46 cm, tinggi: 90 cm, kapasitas produksi : 47 m/jam, penggerak motor listrik 1 phase, 220 volt, 250 watt, 1400 rpm

Quantum Yield Calculations for Strongly Absorbing Chromophores

This article demonstrates that a commonly-made assumption in quantum yield calculations may produce errors of up to 25% in extreme cases and can be corrected by a simple modification to the analysis.Comment: 3 pages, 2 figures. Accepted by Journal of Fluorescenc

Genetic Control of Circuit Function: Vsx1 and Irx5 Transcription Factors Regulate Contrast Adaptation in the Mouse Retina

Transcriptional programs guide the specification of neural cell types in the developing nervous system. However, it is unclear whether such programs also control specific aspects of neural circuit function at maturity. In the mammalian retina, Vsx1 and Irx5 transcription factors are present in a subset of bipolar interneurons that convey signals from photoreceptors to ganglion cells. The biased expression of Vsx1 and Irx5 in hyperpolarizing OFF compared with depolarizing ON bipolar cells suggests that these transcription factors may selectively regulate signal processing in OFF circuits. To test this hypothesis, we generated mice lacking both Vsx1 and Irx5. Bipolar cells in these mice were morphologically normal, but the expression of cell-specific markers in some OFF but not ON bipolar cells was reduced or absent. To assess visual function in Vsx1/Irx5/ retinas, we recorded light responses from ensembles of retinal ganglion cells (RGCs). We first identified functional RGC types in control mice and describe their response properties and adaptation to temporal contrast using a simple linearnonlinear model. We found that spacetime receptive fields of RGCs are unchanged in Vsx1/Irx5/ mice compared with control retinas. In contrast, response threshold, gain, and range were lowered in a cell-type-specific manner in OFF but not ON RGCs in Vsx1/Irx5/ retinas. Finally, we discovered that the ability to adapt to temporal contrast is greatly reduced in OFF RGCs in the double mutant, suggesting that Vsx1 and Irx5 control specific aspects of visual function in circuits of the mammalian retina

Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum ina cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16 100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32 200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable"sensitive volumes.&quot

Can agricultural cultivation methods influence the healthfulness of crops for foods

The aim of the current study was to investigate if there are any health effects of long-term consumption of organically grown crops using a rat model. Crops were retrieved over two years from along-term field trial at three different locations in Denmark, using three different cultivation systems(OA, organic based on livestock manure; OB, organic based on green manure; and C, conventional with mineral fertilizers and pesticides)with two field replicates. The cultivation system had an impact on the nutritional quality, affecting γ-tocopherol, some amino acids, and fatty acid composition. Additionally, the nutritional quality was affected by harvest year and location. However, harvest year and location rather than cultivation system affected the measured health biomarkers. In conclusion, the differences in dietary treatments composed of ingredients from different cultivation systems did not lead to significant differences in the measured health biomarkers, except for a significant difference in plasma IgGl evels

Study protocol: can a school gardening intervention improve children's diets?

BACKGROUND: The current academic literature suggests there is a potential for using gardening as a tool to improve children's fruit and vegetable intake. This study is two parallel randomised controlled trials (RCT) devised to evaluate the school gardening programme of the Royal Horticultural Society (RHS) Campaign for School Gardening, to determine if it has an effect on children's fruit and vegetable intake. METHOD/DESIGN: Trial One will consist of 26 schools; these schools will be randomised into two groups, one to receive the intensive intervention as "Partner Schools" and the other to receive the less intensive intervention as "Associate Schools". Trial Two will consist of 32 schools; these schools will be randomised into either the less intensive intervention "Associate Schools" or a comparison group with delayed intervention. Baseline data collection will be collected using a 24-hour food diary (CADET) to collect data on dietary intake and a questionnaire exploring children's knowledge and attitudes towards fruit and vegetables. A process measures questionnaire will be used to assess each school's gardening activities. DISCUSSION: The results from these trials will provide information on the impact of the RHS Campaign for School Gardening on children's fruit and vegetable intake. The evaluation will provide valuable information for designing future research in primary school children's diets and school based interventions. TRIAL REGISTRATION: ISRCTN11396528