Mg Of Weight Research Articles

Efficient Plant Regeneration with Arabinogalactan-Proteins on Various Ploidy Levels of Cereals

To determine the most effective dose of arabinogalactan-protein (AGP) in regeneration medium, mature embryos of genotypes in three different ploidy levels (Triticum aestivum L. cv. Ikizce-96, Triticum durum Desf. cv. Mirzabey and Hordeum vulgare L. cv. Tokak) were used to establish an efficient plant regeneration system for cereals. Percentage of callus production, capacity of regeneration were calculated, and also culture effect, root, stem, and total plant length of regenerant plants were observed in six different regeneration media (MS control, MS+2, 5, 7, 10, 12 mg L−1 AGP) in these three different genotypes. According to the results, the highest amount of callus production was found in Ikizce-96 as 93.75% using 5 mg L−1 dicamba and 1 mg L−1 kinetin in induction medium. However, the most improved callus was observed in diploid barley Tokak as 179.95 mg in weight and 6.18 mm in diameter, respectively. The highest regeneration capacity was observed in the dose of 5 mg L−1 AGP in MS of all the genotypes and hexaploid wheat Ikizce-96 gave the best results with the highest regeneration capacity and culture effects (94.86 and 92.5%) in the same dose of AGP. These results indicated that effective dose of AGP in regeneration medium increase plant regeneration in calli derived from cereal mature embryos.

Measurement of thermal conductivity of building insulation foams by modulated differential scanning calorimetry — Critical review & observations

Abstract The rise in energy prices, the need to conserve energy and the pressure to protect the environment promote the development of innovative eco-friendly thermal insulating foams for building applications. In this quest, a rapid and accurate method to measure the thermal conductivity of new foams is required during the research and product development stage. Temperature-modulated differential scanning calorimetry (MDSC) provides thermal conductivity values from heat capacity measurements on cylindrical samples less than about 20 mg in weight. This method is the basis of the ASTM E1952 standard method “Thermal Conductivity and Thermal Diffusivity by Modulated Differential Scanning Calorimetry”. In this work, the MDSC and the ASTM E1952 test methods are applied to thermal insulating foams used in construction applications. Measurements on polystyrene, polyurethane, and polyisocyanurate insulations demonstrate that MDSC possesses excellent repeatability, but its application through ASTM E 1952 provides inaccurate thermal conductivity values. Two sources of errors were identified, 1) the use of nitrogen as a purge gas, and 2) the use of an equation that inaccurately relates the measured heat capacity to thermal conductivity. Methods around these difficulties exist, but they remain untested with insulating foams.

Anti-tick monoclonal antibody applied by artificial capillary feeding in Rhipicephalus (Boophilus) microplus females

The tick Rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. However, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. In this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. Capillary tube artificial feeding of partially engorged R. microplus females with monoclonal antibodies against proteins from the gut of tick were used to test the effects of immunoglobulins in the physiology of the parasite. The results of artificial feeding showed that female ticks over 25mg and under 60mg in weight performed better in the artificial feeding process, with a 94–168% weight increase after 24h of feeding. Results showed that artificial feeding of ticks proved to be a viable technique to study the effects of antibodies or drugs in the physiology of the parasite. One monoclonal antibody (BrBm2) induced decreased oviposition. Moreover, the antigen recognized by BrBm2 was identified as a 27-kDa protein and immunolabeled on digestive vesicles membranes of digestive cells of partially and fully engorged females.

Intraspecific Competition Effects on Aethina tumida (Coleoptera: Nitidulidae)

Two kinds of experiments were conducted with Aethina tumida Murray larvae over four temperatures: "consumption" experiments, in which larvae and diet were weighed to determine food consumption rates under conditions of unlimited food and few conspecifics; and "competition" experiments, in which varying numbers of larvae were presented with the same amount of honey and pollen diet, and larval weight at final instar was used to determine competition effects. In consumption experiments temperature, diet and their interaction all had significant effects on the ratio of larval weight to the weight of food consumed, which was higher at 24 degrees C than at any other temperature. In competition experiments, three relationships were examined and modeled: that between the number of larvae per experimental unit and the average weight of those larvae; that between average larval and adult weights; and that between average adult weight and survivorship to adult (emergence rate). An exponential decay function was fit to the relationship between number of larvae per experimental unit and their average weight. Average adult weight was linearly correlated with larval weight. Likewise, emergence rates for adults < 11.6 mg in weight were linearly correlated with adult weights, but no significant relationship was observed for heavier adults. Using these relationships, the reproductive potential for A. tumida were estimated for a frame of honey and pollen. Information on resource acquisition by A. tumida will be useful in evaluating the impact of different factors on beetle population dynamics, such as bee hygienic behavior or control strategies used by the beekeeper.

Jumping mechanisms in jumping plant lice (Hemiptera, Sternorrhyncha, Psyllidae)

Jumping mechanisms and performance were analysed in three species of psyllids (Hemiptera, Sternorrhyncha) that ranged from 2 to 4 mm in body length and from 0.7 to 2.8 mg in mass. Jumping was propelled by rapid movements of the short hind legs, which were only 10-20% longer than the other legs and 61-77% of body length. Power was provided by large thoracic muscles that depressed the trochantera so that the two hind legs moved in parallel planes on either side of the body. These movements accelerated the body to take-off in 0.9 ms in the smallest psyllid and 1.7 ms in the largest, but in all species imparted a rapid forward rotation so that at take-off the head pointed downwards, subtending angles of approximately -60 deg relative to the ground. The front legs thus supported the body just before take-off and either lost contact with the ground at the same time as, or even after, the hind legs. In the best jumps from the horizontal, take-off velocity reached 2.7 m s(-1) and the trajectory was steep at 62-80 deg. Once airborne, the body spun rapidly at rates of up to 336 Hz in the pitch plane. In many jumps, the wings did not open to provide stabilisation, but some jumps led directly to sustained flight. In their best jumps, the smallest species experienced a force of 637 g. The largest species had an energy requirement of 13 μJ, a power output of 13 mW and exerted a force of nearly 10 mN. In a rare jumping strategy seen in only two of 211 jumps analysed, the femoro-tibial joints extended further and resulted in the head pointing upwards at take-off and the spin rate being greatly reduced.

Stability of the Infection Marker Struvite in Urinary Stone Samples

Struvite in kidney stones is an important marker for infection. In kidney stone samples, struvite is known to be prone to chemical breakdown, but no data exist on the stability of samples stored in dry form. The objective of this study was to examine stability of struvite under increasingly poor conditions of storage. Samples of struvite kidney stones were broken to obtain 38 pieces averaging 67 mg in weight, and these were randomized into four storage conditions: Airtight containers stored in the dark, open containers in the dark, open containers in ambient light, and open containers at elevated temperature (40°C). Pieces were left for 6 months, and then analyzed for changes using micro CT and Fourier transform infrared spectroscopy (FT-IR). Initial samples proved to be struvite, indicating no transformation in the large specimens that had been stored in airtight containers in the dark for more than 6 years before this study. Pieces of struvite taken from these large specimens appeared unchanged by micro CT and FT-IR after being stored in closed containers for 6 months, but 8 of 9 pieces in open containers showed the presence of newberyite in surface layers, as did 10 of 10 pieces in open containers out in ambient light. All pieces stored at 40°C showed transformation of struvite, with 60% of the pieces showing the presence of amorphous phosphates, indicating complete breakdown of struvite in the surface layers of the pieces. We conclude that struvite in dry kidney stone samples is stable when the specimens are stored in airtight containers at room temperature, even after several years.

Engineering Adipose Tissue from Uncultured Human Adipose Stromal Vascular Fraction on Collagen Matrix and Gelatin Sponge Scaffolds

Adipogenic potential was evaluated in uncultured stromal vascular fraction (SVF) loaded onto porous 3D collagen matrix and gelatin sponge scaffolds with predefined shapes. The SVF was isolated from 16 freshly lipectomized fat. Mean cell number was 6.0±4.68×10(7) cells/mL, and mean cell viability was 72%. Flow cytometric analysis revealed adipose-derived stromal cells (CD31(-), CD34(-/+), CD45(-), CD90(+), CD105(-), CD146(-), and CD166(+)) in the SVF. Three hours after harvest of fat, 200 μL of isolated SVF was loaded onto an experimental scaffold (4 mg in weight) and cultured in Dulbecco's modified Eagle's medium. Examination of the construct under an inverted light microscope and a scanning electron microscope demonstrated adequate seeding and active proliferation of the SVF cells on pore surfaces. Cells grew to varying sizes in clusters or in strands. On day 28, histologic study of the constructs by H&E staining revealed viable adipocytes in the microstructure. Positive Oil-Red O stain confirmed lipid accumulation in mature adipocytes. The presence of human adipocytes was further assessed by the presence of genomic DNA detected by GAPDH gene and by the mRNA expression of peroxisome proliferator activated receptor-γ, and lipoprotein lipase. The results demonstrated that new adipose tissue can be regenerated by seeding freshly isolated, uncultured SVF on 3D porous collagen matrix and gelatin sponge scaffolds.

G020034 チョウの離陸時における圧力差分布([G02003]バイオエンジニアリング部門一般セッション(3))

This paper reports on direct measurement of differential pressure distribution on a butterfly wing during takeoff. Differential pressure was measured with a micro-fabricated sensor. A MEMS (Micro Electro Mechanical Systems) piezo-resistive cantilever was used as the differential pressure sensor. The sensor chip was 1.0 mm x 1.0 mm x 0.3 mm in size and 0.7 mg in weight. The sensor was attached to a butterfly (Papilio protenor) wing surface through a Cu/Polyimide substrate and Au wires. The total weight was 30 mg so that it did not interfere with flight condition. The distribution of five points to the spanwise direction at the forewing and one point at the center of the hindwing was measured during takeoff. As a result, it was clarified that the maximum differential pressure was 20 Pa on the forewing tip. Additionally, the maximum aerodynamic force generated on the wing was 3 times larger than the gravity acting on the body.

Tilapia growth hormone binds to a receptor in brush border membrane vesicles from the hepatopancreas of shrimp Litopenaeus vannamei

Tilapia growth hormone (GH) was used to determine the presence of a presumed protein with GH receptor-like function in the hepatopancreas of shrimp L. vannamei and to evaluate its effect on growth of L. vannamei postlarvae. The receptor assay was performed using brush border membrane vesicles (BBMV) from the hepatopancreas of L. vannamei and the affinity constant was calculated by the dilution coordinates method. The shrimp postlarvae treated with tilapia GH were 42.4% heavier and 5.2% longer than the control group ( P < 0.05). On the other hand, the water content was lower in the postlarvae treated with GH (75.9%) than in the control group (77.3%) ( P < 0.05). Content of soluble proteins per mg of weight was 1.33 times higher in the GH-treated animals than control animals. No significant differences in survival rates were detected between the experimental groups. Tilapia GH was able to bind to a GH receptor-like protein on BBMV with an affinity constant of 1.30 ⁎ 10 8 M − 1 . In conclusion, a GH receptor-like protein was detected on vesicles from hepatopancreas of the shrimp L. vannamei. Also, it was established that the TiGH was able to enhance the growth of shrimp postlarvae. To our knowledge, this is the first report to demonstrate an interaction between a vertebrate growth hormone and a GH receptor-like protein of a crustacean.

Interaction of a complexing agent with urolith as the basis for efficient little-invasive therapy of phosphaturia

The solubility of phosphate–oxalate urinary calculi in solutions of complexing agents was studied using a specially developed flow reactor at 37°C. The treat� ment of calculi 30–90 mg in weight for 2 h was found to significantly change the surface structure of the cal� culi and decrease the sample weight. The average sol� ubilities of uroliths in a solution of sodium citrate Na 3 Cit (5%, pH 8.6), a citrate buffer solution (pH 6.4), and a solution of sodium ethylenediaminetetraacetate Na 2 H 2 EDTA (pH 4.6) are 17.5 ± 4, 35.2 ± 3, and 54.2 ± 8 wt %, respectively. Based on the results obtained, developed litholysis methods of residual concrements are proposed. Urolithiasis is a widespread disorder all over the world, affecting no less than 5–10% of population. More than 70% of calculi are made of calcium oxalate and calcium phosphate or their mixtures [1–3]. In this connection, no wonder that a wide circle of researches are interested in understanding mecha� nisms of stone formation, inhibiting stone deposition, and determining the conditions for spontaneous dis� charge of concrements [3–7]. In particular, citrate and ethylenediaminetetraacetate anions were shown [6, 7] to be inhibitors of deposition due to formation of complexes with Ca 2+ ion [8]. Citrate ions excreted in urine are precisely the species, which play this role in organism [4, 5]. In the present work, we studied in vitro interaction of aqueous solutions of chelating agents with phos� phate–oxalate calculi in order to develop a quantita� tive experimental base for chelation therapy. EXPERIMENTAL Reagents Na2H2EDTA (more than 99%, Che� mapol) and Na 3 Cit (more than 99%, Panreac) were used without additional purification. The reagents were dried in vacuum at 80°C to constant weight. The weighed salt samples were dissolved in appropriate vol� umes of bidistilled water. A citrate buffer (pH 6.4) was prepared by a standard procedure [9]. Phosphate– oxalate stones were obtained after surgical procedures (pyelolithotomy or ureterolithotomy) at Ivanovo State

Regulation of retinol binding protein 4 production in primary human adipocytes by adiponectin, troglitazone and TNF-α

To the Editor: Adipose tissue has an important endocrine function, producing a variety of bioactive proteins that may regulate energy metabolism and insulin sensitivity. It releases a variety of the so-called adipokines, including retinol binding protein 4 (RBP4), which has recently been described as a link between obesity and insulin resistance [1] in addition to its primary function as a specific carrier of vitamin A in the blood. In diabetic patients, RBP4 levels are correlated with the degree of insulin resistance [2] and with components of the metabolic syndrome, such as BMI, triacylglycerol levels and blood pressure. Conversely, exercise and weight loss have been reported to decrease both RBP4 levels and insulin resistance [2]. However, the link between RBP4 and obesity is controversial, as several other studies have not found RBP4 to be associated with overall obesity or insulin resistance [3, 4]. In addition, one study reported no difference in circulating RBP4 levels between lean and obese women [5], a finding confirmed very recently [6]. Furthermore, subcutaneous adipose tissue from obese women was characterised by lower RBP4 production compared with lean controls [5]. In these adipose tissue biopsies, GLUT4 levels correlated with RBP4 concentration, making it more likely that RBP4 levels positively correlate with insulin sensitivity in this study. Data on RBP4 production and regulation in human adipocytes are not available, and so the contribution of adipocytes to adipose tissue RBP4 output is difficult to evaluate. In the present study, primary human preadipocytes were isolated from mammary adipose tissue samples of normal or moderately overweight women (age 40.5±3.8 years, BMI 24.2±2.7 kg/m, n=4 in each group) undergoing surgical mammary reduction. All subjects were healthy, free of medication and had no evidence of diabetes according to routine laboratory tests. Adipose tissue samples were dissected from other tissues, pieces of ∼10 mg in weight were minced and preadipocytes were isolated by collagenase digestion as previously described [7]. Isolated preadipocytes were seeded in DMEM/Hams F12 medium supplemented with 10% fetal calf serum and kept in culture overnight. Adipocytes were differentiated over 15 days in a differentiation medium (DMEM/F12, 33 μmol/l biotin, 17 μmol/l D-pantothenic acid, 66 nmol/l insulin, 1 nmol/l triiodo-L-thyronine, 100 nmol/l cortisol, 10 μg/ml apotransferrin, 50 μg/μl gentamicin, 15 mmol/l HEPES, 14 mmol/l NaHCO3, pH 7.4). After 15 days of culture, 60–80% of cells were differentiated as defined by cytoplasm filled with small or large lipid droplets. Differentiated adipocytes were treated with recombinant human adiponectin (Tebu, Offenbach, Germany), troglitazone and recombiDiabetologia (2007) 50:2221–2223 DOI 10.1007/s00125-007-0764-3

A novel in vitro hydroponic culture system for potato (Solanum tuberosum L.) microtuber production

An innovative in vitro hydroponic culture system used in potato (Solanum tuberosum L.) microtuber production is described in this paper. In vitro potato plantlets, 6–8 cm in height, derived from meristems of potato tubers cultured on 1/2 Murashige and Skoog (MS) nutrient medium after 30 days culture were cut into 1.5 cm stem node segments and used as explants. These stem nodes were cultured in a novel system called in vitro hydroponic culture system containing 1/2 MS medium supplemented with 0.5 μM naphthaleneacetic acid (NAA), 0.3 μM gibberellic acid (GA3), 3.7 μM adenine sulfate, 10% coconut water, 0.5 g/l activated charcoal, 80 g/l sucrose with or without 8 g l−1 agar. Liquid medium was distributed to the carrier substrates in each storey of the system with the aid of capillary robes. In the present paper, the effects of porous material used as substrate carrier and the number of storeys involved in the culture system on microtuber formation and their morphological characteristics are reported. Cotton layer substrate is more stable for organogenesis of potato microtubers. Microtubers, 3.19 mm in diameter and 49.82 mg in weight, could be harvested from a one-storey in vitro hydroponic culture system containing filter paper as substrate. However, microtubers cropped from three-storey in vitro hydroponic culture system with cotton layer were bigger and weightier than those from three-storey system containing filter paper. The above results of the in vitro hydroponic system examined in this study might open up a new approach in producing potato and other hygrophilous microtuber.

Differential Expression Profiling of the Hepatic Proteome in a Rat Model of Dioxin Resistance

One characteristic feature of acute 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity is dramatic interspecies and interstrain variability in sensitivity. This complicates dioxin risk assessment for humans. However, this variability also provides a means of characterizing mechanisms of dioxin toxicity. Long-Evans (Turku/AB) rats are orders of magnitude more susceptible to TCDD lethality than Han/Wistar (Kuopio) rats, and this difference constitutes a very useful model for identifying mechanisms of dioxin toxicity. We adopted a proteomic approach to identify the differential effects of TCDD exposure on liver protein expression in Han/Wistar rats as compared with Long-Evans rats. This allows determination of which, if any, protein markers are indicative of differences in dioxin susceptibility and/or responsible for conferring resistance. Differential protein expression in total liver protein was assessed using two-dimensional gel electrophoresis, computerized gel image analysis, in-gel digestion, and mass spectrometry. We observed significant changes in the abundance of several proteins, which fall into three general classes: (i) TCDD-independent and exclusively strain-specific (e.g. isoforms of the protein-disulfide isomerase A3, regucalcin, and agmatine ureohydrolase); (ii) strain-independent and only dependent on TCDD exposure (e.g. aldehyde dehydrogenase 3A1 and rat selenium-binding protein 2); (iii) dependent on both TCDD exposure and strain (e.g. oxidative stress-related proteins, apoptosis-inducing factor, and MAWD-binding protein). By integrating transcriptomic (microarray) data and genomic data (computational search of regulatory elements), we found that protein expression levels were mainly controlled at the level of transcription. These results reveal, for the first time, a subset of hepatic proteins that are differentially regulated in response to TCDD in a strain-specific manner. Some of these differential responses may play a role in establishing the major differences in TCDD response between these two strains of rats. As such, our work is expected to lead to new insights into the mechanism of TCDD toxicity and resistance.

C305 蝶の飛翔時の翅まわりに形成される渦流れ

Recently, a few studies on development of Micro-Air-Vehicle and micro flight robot have been attracting attentions. However, these robots have not been applied yet because flight mechanisms of butterfly and bird have not been understood sufficiently. In this study, in order to clarify a vortex flow structure on a butterfly wing, we have carried out flow visualization on a butterfly wing using the particle and a high-speed camera. The test butterfly is cynthia cardui and its diameter is 25 mm in wing chord length, 30 mm in wing span length, 254 mm2 in wing area and 160 mg in weight. Especially, we have discussed about the vortex flow developed on wing chord and span lengths.

Effect of pink pineapple mealybug hosts on Anagyrus ananatis Gahan size and progeny production

Abstract Studies were conducted to improve the colony production of Anagyrus ananatis Gahan (Hymenoptera: Encyrtidae) when reared on the pink pineapple mealybug (PPM), Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae). Parasitization of large PPM (>0.85 mm length) by A. ananatis resulted in an almost 3:1 ratio of female:male offspring. A strong positive correlation (r2 = 0.8935) was found between PPM weight and parasitoid size (i.e., length). Male parasitoids were not as food limited as females when the mealybug host was small. Despite the ability of A. ananatis to parasitize all host stages except crawlers, gravid adult female PPM produced larger parasitoids with higher fecundity. Allowing PPM to continue feeding on squash following parasitization produced larger parasitoids. However, for A. ananatis propagation it is more efficient to remove PPM from squash hosts and size them (via sieving) before exposing them to the parasitoid. Mealybugs >0.6 mg in weight and >0.5 mm in size can be used for parasitoid rearing to produce female A. ananatis (>1.4 mm length) that exhibit fecundities similar to those for A. ananatis that developed on PPM that fed on squash following parasitization (∼28 progeny per female). Furthermore, to maintain an A. ananatis female-biased sex ratio, PPM hosts >0.6 mm (medium size) would be preferable for use in parasitoid colony production. The length and width of PPM mummies were good predictors of the sex and body size of the parasitoid contained within, and may be potentially used as important indicators of parasitoid quality and fitness in a mass production system.

D314 蝶の飛翔における翅の挙動

In order to clarify the flight mechanism of butterfly, we have observed the butterfly flight using high-speed camera. The Test butterfly is Cynthia cardui and its diameter is 25mm in wing chord length, 30mm in wing span length, 254mm2 in wing area and 160mg in weight. Especially, we have discussed the dynamic behavior of butterfly wing in flight motion, such as the elastic deformation of wing, the trajectory of wing tip and the flapping angle of wing. In flight motion of butterfly, the wing carried out elastic deformation not only in the wing span direction but also in the wing chord direction. The flapping angle shows the periodic triangular waveform and the ratio of between the up stroke and down stroke of flapping motion is about 1:1.25.

The productivity of irrigated legumes in northern Victoria. 3. Frequency and intensity of defoliation of subterranean clover

An experiment was undertaken to consider the effects of a range of defoliation treatments on aspects of the productivity of a subterranean clover (Trifolium subterraneum L.) sward (predominantly cv. Trikkala), with particular emphasis on flowering and seed production. There were 2 heights of defoliation, 2.8 and 7.0 cm (rising plate meter) above ground level, and at each height of defoliation, there were 4 intervals of harvest, 4, 6, 9 and 12 weeks. Treatments were arranged randomly within blocks, and there were 4 replicates. Harvests were conducted between autumn (6 April) and spring (13 November). The total production of herbage varied from 5.7 to 8.7 t DM/ha of harvested material, with variations in response due to both height and frequency of defoliation. Harvested yield increased from 6.2 to 7.4 t DM/ha (P&lt;0.05) as interval between harvests was extended, and plots harvested to 2.8 cm above ground level yielded more (7.7 t DM/ha; P&lt;0.05) harvested herbage than those harvested to 7.0 cm (6.0 t DM/ha). While there were differences in production due to defoliation management, nutritive characteristics (DM digestibility, crude protein, neutral detergent fibre) of harvested herbage were similar in all treatments throughout the year. Production of above and below ground seed increased (P&lt;0.05) as interval between harvest increased, and was greater (P&lt;0.05) at the higher defoliation height. Defoliating at 4- and 6-week intervals interrupted the reproductive development of Trikkala; late September–early October harvests substantially reduced both subsequent petiole extension and flower production. This resulted in Trikkala seeds of lower weight in the above ground seed pool (P&lt;0.05). This may have impacted on regenerating ability in the next autumn because Trikkala seeds that were less than about 4 mg in weight were less likely to germinate than heavier seed. In conclusion, the highest dry matter production occurred with intensive, infrequent defoliation whereas highest seed yields were produced with lax, infrequent defoliation.

Significance of point of no return in therapeutic strategy for treatment of renal osteodystrophy; from histopathological findings

Point of no return implies a stage at irreversible to medical treatment of secondary hyperparathyroidism, clinically equivalent to intact PTH levels are more than 500 pg/mL in Japan. Most of glands resected by parathyroidectomy indicate nodular hyperplasia, increased parathyroid cell proliferation. Down-regulation of calcium sensing receptors and vitamin D receptors in nodular parathyroid cells become a cause of resistance to medical treatment. Most of nodular glands are more than 500 mg in weight, predictable to existence at estimated volume and gland color signals by ultrasonographic method. New options both parathyroid injection therapy using ethanol and active vitamin D, and calcimimetic agent have a potential to change point of no return in therapeutic strategy for secondary hyperparathyroidism.

Seasonal and Geographic Variation in Juvenile Pink Salmon Diets in the Northern Gulf of Alaska and Prince William Sound

AbstractFish survival is often determined early in life and can be affected by diet and prey availability. To understand how climate changes affect food web dynamics and salmon survival, it is important to know the types of prey that salmon consume. We describe geographic and seasonal differences in the diets of juvenile pink salmon Oncorhynchus gorbuscha during 3 months of early ocean residence in Prince William Sound (PWS) and the Gulf of Alaska (GOA). Fish were sampled in PWS in July and in the GOA in July, August, and October. The diets and standard lengths of pink salmon varied significantly among stations within each sampling period. There was no discernable geographic pattern in fish length variability. Pink salmon in PWS (July) generally consumed small prey items, such as gastropods, cladocerans, small calanoid copepods, and bivalves, along with some large prey items, such as large calanoid copepods and larvaceans. In August, juvenile pink salmon sampled in the GOA consumed fewer small prey items, and most of their prey biomass consisted of pteropods Limacina spp., larvaceans, hyperiid amphipods, and euphausiids. Prey items consumed by fish sampled in October in the GOA were larger. The prey items that comprised the largest biomass were large pteropods Clio spp., large hyperiid amphipods, euphausiids, crab megalopae, and fish. Prey size increased over the three sampling periods. Fish shorter than 150 mm consumed prey smaller than 3 mg in weight, whereas larger fish tended to consume larger prey weighing up to 16 mg. Pink salmon diets differed among stations as little as 20 km apart.

Detection of Bone Fragments in Chicken Meat using X-ray Backscatter

X-ray backscatter was used to detect near-surface fragments of chicken clavicle, 2 cm long and 20–60 mg in weight, in polystyrene phantoms and in samples of breast meat. The densities of clavicle fragments and pieces of breast meat were measured by Archimedes’ method, and were respectively 1·32±0·05 and 1·07±0·007 g cm −3. Samples were prepared consisting of blocks of polystyrene, or of chicken breast, into which fragments of clavicle were inserted, approximately 0·1 cm below the surface. The samples were scanned in front of a 140 kVp X-ray source, and the backscattered X-rays were counted by a detector collimated at 135° to the beam. The spatial resolution was 0·1 by 0·1 cm in the source–sample–detector plane, and 2 cm in the perpendicular direction. The scattered spectra were collected, and for each spectrum, three quantities were plotted against sample position: the counts in a 10–40 keV energy window; the counts in a 40–95 keV energy window; and the mean spectral energy over the range 10–95 keV. The contrasts from these measurements were compared with those obtained in transmission images. The detected counts in the 10–40 keV energy window showed little positive contrast, but strong negative contrasts due to attenuation. The contrasts ranged from −13 to −25·8%, and the signal-to-noise ratios (normalised for a 30 mA source at 1 s sampling time) were 5·8–11·7. The detected counts in the 40–95 keV energy window showed peaks in the backscatter when the scan passed across a bone fragment. The contrasts ranged from 4·2 to 14·7%, and the signal-to-noise ratios from 1·6 to 5·6. The mean spectral energy gave results intermediate between the two, with contrasts in the range 1·7–6·7% and signal-to-noise ratios from 3·0 to 11·0. The 10–40 keV energy window gave contrasts which were larger than those in the transmission images, and the 40–95 keV energy window gave contrasts similar to the transmission images.