Photoluminescence Studies of Lateral Composition Modulated Short-Period AlAs/InAs Superlattices

We present low temperature photoluminescence data for a series of spontaneous lateral composition modulation in (AlAs){sub m}/(InAs){sub n} short period superlattices on InP with differing average lattice constants, i.e., varying global strain. The low temperature photoluminescence peak energies were found to be much lower than the corresponding energy expected for the equivalent In{sub x}Al{sub 1{minus}x}As alloy. The bandgap energy reductions are found to approach 500 meV and this reduction is found to correlated with the strength of the composition modulation wave amplitude

Influence of Neonatal Hypothyroidism on Hepatic Gene Expression and Lipid Metabolism in Adulthood

Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology, but its specific influence in liver is less understood. Here, we studied how CH influences the liver gene expression program in adulthood. Pregnant rats were given the antithyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as reductions in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, the feed efficiency increased in CH, and this was accompanied by significant catch-up growth. On PND80, significant reductions in body mass, tail length, and circulating IGF-I levels remained in CH rats. Conversely, the mRNA levels of known GH target genes were significantly upregulated. The serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in the expression of hepatic genes involved in lipid metabolism, including an increased transcription of PPARα and a reduced expression of genes involved in fatty acid and cholesterol uptake, cellular sterol efflux, triglyceride assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to the onset of hypothyroidism in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters and to T3 replacement with an enhanced activation of malic enzyme. In summary, we provide in vivo evidence that neonatal hypothyroidism influences the hepatic transcriptional program and tissue sensitivity to hormone treatment in adulthood. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood

UNIFORMITY OF PHOTOSYNTHETIC PHOTON FLUX AND GROWTH OF 'POINSETT' CUCUMBER PLANTS UNDER METAL HALIDE AND MICROWAVE-POWERED SULFUR LAMPS

The uniformity of photosynthetic photon flux (PPF) and vegetative growth of Cucumis sativus L. ('Poinsett' cucumber) were examined using growth chambers equipped with either six 400W metal halide (MH) lamps or with a single 1000W microwave-powered sulfur (MPS) (LIGHTDRIVE^ 1000) lamp mounted on a polished stainless steel reflector with secondary screening for microwave protection. PPF levels in each growth chamber were set initially at 500μmol m^ s^. Pots were placed at equal distance from one another in ten columns of six rows each (n=60). Growth measurements were only taken on the center six columns of plants (n=36). The uniformity of PPF was greater in the MPS than in the MH chamber for both the 36 and the 60 pot arrangement. However, growth measurements showed similar variance in the MH as in the MPS chamber. Plants grown for 14 days under MPS lamps had significantly greater growth than those under MH lamps. Petiole length, total stem length, and leaf enlargement were 90%, 44%, and 34% greater, respectively, in plants grown under MPS lamps than under MH lamps. Similar differences were obtained in biomass; dry weights of tops and roots of MPS grown plants were 28% and 36%, greater, respectively, than those of MH grown plants. These findings demonstrate the potential of using sulfur lamps for accelerating seedling production under controlled environments and validate the concept that sulfur lamps have a better spectral quality for plant growth than metal halide lamps. These results should be of interest to growers and researchers involved in protected cultivation. The LIGHTDRIVE^ 1000 sulfur lamp should also provide a useful tool for studying the photocontrol of shoot development

UNIFORMITY OF PHOTOSYNTHETIC PHOTON FLUX AND GROWTH OF \u27POINSETT\u27 CUCUMBER PLANTS UNDER METAL HALIDE AND MICROWAVE-POWERED SULFUR LAMPS

The uniformity of photosynthetic photon flux (PPF) and vegetative growth of Cucumis sativus L. (\u27Poinsett\u27 cucumber) were examined using growth chambers equipped with either six 400W metal halide (MH) lamps or with a single 1000W microwave-powered sulfur (MPS) (LIGHTDRIVE^<TM> 1000) lamp mounted on a polished stainless steel reflector with secondary screening for microwave protection. PPF levels in each growth chamber were set initially at 500μmol m^<-2> s^<-1>. Pots were placed at equal distance from one another in ten columns of six rows each (n=60). Growth measurements were only taken on the center six columns of plants (n=36). The uniformity of PPF was greater in the MPS than in the MH chamber for both the 36 and the 60 pot arrangement. However, growth measurements showed similar variance in the MH as in the MPS chamber. Plants grown for 14 days under MPS lamps had significantly greater growth than those under MH lamps. Petiole length, total stem length, and leaf enlargement were 90%, 44%, and 34% greater, respectively, in plants grown under MPS lamps than under MH lamps. Similar differences were obtained in biomass; dry weights of tops and roots of MPS grown plants were 28% and 36%, greater, respectively, than those of MH grown plants. These findings demonstrate the potential of using sulfur lamps for accelerating seedling production under controlled environments and validate the concept that sulfur lamps have a better spectral quality for plant growth than metal halide lamps. These results should be of interest to growers and researchers involved in protected cultivation. The LIGHTDRIVE^<TM> 1000 sulfur lamp should also provide a useful tool for studying the photocontrol of shoot development

Publisher: Institute for Animal Husbandry, Belgrade-Zemun UDC 637.04:637.353 DOI:10.2298/BAH1004167B THE INFLUENCE OF CHEMICAL COMPOSITION OF MILK ON YIELD OF SEMI-HARD CHEESE

Abstract: The aim of paper was to examine the impact of the milk quality on yield of semi-hard naturally dried cheese, produced in cheese plant factory ZZ “Cijevna ” in Podgorica. Tests were conducted on 6 samples of bulk milk of cows and 6 productive batch of cheese. Chemical tests of the bulk milk have been done on the device MilcoScan 4000, and the determination content dry matter of whey and dry matter of cheese on the device MilcoScan FT 120. Theoretical yield of cheese was determined in two ways: 1) based on the content of fat and protein content in milk and 2) based on dry matter content of milk, dry matter of whey and dry matter of cheese. Actual yield of cheese is determined on the base of the total amount of cheese obtained after pressing and the amount of wasted milk. The average value for the fat content in the examined milk amounted to 3.79%, protein 3.24%, 4.26 % lactose and dry matter content without fat 8.24%. The average value for the theoretical cheese yield by first method was 10.65 % and by second method 9,30%. The average of actual cheese yield amounted to 11.26%. We found a very high positive correlation between content of fat in milk and actual cheese yield (0.929032) and mean positive correlation between content of protein in milk and actual cheese yield (0.613141), content of lactose in milk and actual cheese yield (0.651317) and between dry matter content in milk and actual cheese yield (0.651956). Key word: milk, composition, cheese, yiel

SPECTRAL PROPERTIES OF MICROWAVE-POWERED SULFUR LAMPS IN COMPARISON TO SUNLIGHT AND HIGH PRESSURE SODIUM/METAL HALIDE LAMPS

The spectral properties of 3.4kW microwave-powered sulfur (MPS) lamps were compared with sunlight and with a combination of high-pressure sodium (HPS) and metal halide (MH) lamps. Photosynthetic photon flux (PPF) levels at 1.2m from the MPS lamps (half and full power) and the HPS/MH lamps were 565, 1650, and 875μmol m^s^, respectively, versus 2000μmol m^s^ for sunlight. The percent of spectral irradiance from bare MPS lamps operated at full power was comparable to that of sunlight in the 400-500nm (blue) and 600-700nm (red) regions but was 60% higher in the 500-600nm (yellow) region. On a percent distribution basis, HPS/MH lamps had 50% less blue, nearly 25% more red, and twice as much yellow irradiance as sunlight. On a percent basis, MPS and HPS/MH lamps emitted one third to one half as much 700-792nm (far-red) irradiance as sunlight. At half power, there was a significant shift in spectral output of the MPS lamps from the red to the blue region. Measurements taken with a pyranometer and a pyrgeometer indicate that the biggest difference between MPS and HPS/MH lamps was in the 0.8 to 3.0μm (near infrared, NIR) region; MPS lamps emitted one quarter as much NIR as HPS/MH lamps or the sun on a normalized basis (Jμmol^). There was no appreciable difference in far IR (3 to 50μm) between half power MPS and HPS/MH lamps, while at full power, MPS lamps had only one half as much far IR. Based on their spectral characteristics and high PPF, MPS lamps should provide an excellent source of radiant energy for use in plant growth chambers

SPECTRAL PROPERTIES OF MICROWAVE-POWERED SULFUR LAMPS IN COMPARISON TO SUNLIGHT AND HIGH PRESSURE SODIUM/METAL HALIDE LAMPS

The spectral properties of 3.4kW microwave-powered sulfur (MPS) lamps were compared with sunlight and with a combination of high-pressure sodium (HPS) and metal halide (MH) lamps. Photosynthetic photon flux (PPF) levels at 1.2m from the MPS lamps (half and full power) and the HPS/MH lamps were 565, 1650, and 875μmol m^<-2>s^<-1>, respectively, versus 2000μmol m^<-2>s^<-1> for sunlight. The percent of spectral irradiance from bare MPS lamps operated at full power was comparable to that of sunlight in the 400-500nm (blue) and 600-700nm (red) regions but was 60% higher in the 500-600nm (yellow) region. On a percent distribution basis, HPS/MH lamps had 50% less blue, nearly 25% more red, and twice as much yellow irradiance as sunlight. On a percent basis, MPS and HPS/MH lamps emitted one third to one half as much 700-792nm (far-red) irradiance as sunlight. At half power, there was a significant shift in spectral output of the MPS lamps from the red to the blue region. Measurements taken with a pyranometer and a pyrgeometer indicate that the biggest difference between MPS and HPS/MH lamps was in the 0.8 to 3.0μm (near infrared, NIR) region; MPS lamps emitted one quarter as much NIR as HPS/MH lamps or the sun on a normalized basis (Jμmol^<-1>). There was no appreciable difference in far IR (3 to 50μm) between half power MPS and HPS/MH lamps, while at full power, MPS lamps had only one half as much far IR. Based on their spectral characteristics and high PPF, MPS lamps should provide an excellent source of radiant energy for use in plant growth chambers

Localization of nickel in the hyperaccumulator plant Breynia cernua (Poir.) Mull.Arg. discovered in the nickeliferous laterites of Zambales, the Philippines

A newly discovered nickel (Ni) hyperaccumulator plant, Breynia cernua (Phyllanthaceae) from the nickeliferous laterites of Acoje, Zambales, has elevated Ni concentrations. Its computed bioaccumulation factor is 1.7 and the translocation factor is 4.6. Leaf tissues which contain the highest Ni concentrations were analyzed using optical microscopy and Scanning Electron Microscopy with Energy-Dispersive X-ray (SEM/EDX). The results indicated that most of the Ni are stored in the epidermal cells of the leaves, followed by the mesophyll cells then the vascular bundles. The accumulation of Ni found in the subcellular locations, probably in the vacuoles, may prevent phytotoxicity that could affect the normal function of other cellular structures. A possible resistance mechanism through strain avoidance towards Ni accumulation makes B. cernua capable of tolerating elevated Ni concentrations in its tissues. The tolerance of B. cernua to Ni phytotoxicity suggests possible applications of this hyperaccumulator plant in phytoextraction technology