The conservation status of the spectacled petrel Procellaria conspicillata

The spectacled petrel Procellaria conspicillata is listed as critically endangered due to its small population size and ongoing mortality on long-lines. Spectacled petrels were counted in 2004, repeating a census made in 1999 at their sole breeding locality, Inaccessible Island. The 2004 survey took place earlier in the breeding season than the previous count, allowing for more robust estimates of burrow occupancy. During early incubation, birds responded to call playback at 69% of burrow entrances, but birds in at least 8% of burrows remained silent. Birds in shallow burrows were less likely to respond to playback than were those in deep burrows. Two repeat trials at 100 marked nests showed that at least 61% of apparently ‘unoccupied’ burrows were occupied on subsequent checks, resulting in an overall occupancy estimate of 91%. Occupancy was equally high in peripheral colonies. The apparent spatial extent of colonies increased slightly from 1999, and the estimate of total burrow numbers increased by 50%, from 5900 burrows in 1999 to 8900 in 2004. Validation surveys indicated that burrow numbers were underestimated (84 ± 3%) to the same extent as that in 1999 (85 ± 4%), and repeat checks of one colony where all nests were marked showed that even careful counts underestimated actual numbers of burrows by up to 10%. This suggests there are some 11-12,000 burrows, and assuming 90% occupancy, the adult population is likely to be at least 20,000 birds. The population has increased over the last five years, continuing the apparent recovery from a very small population size in the early 20th century. Despite this increase, demographic models indicate that the population remains at risk from relatively small increases in mortality, if mortality is determined primarily by fishing effort. Mitigation of long-line mortality remains the key conservation goal for this species.     

A semi-purified test diet for Macrobrachium rosenbergii and the lack of need for supplemental lecithin

Post-larval Macrobrachium rosenbergii were reared for 12 weeks at 27°C in a recirculated aquatic system on semi-purified diet supplemented with between 0 and 10% lecithin. No significant differences were detected in either the weight gain or mortality rates of the prawn reared on the different test diets and no sign of ‘molt death syndrome’ was observed in any of the prawn. It was concluded that supplemental lecithin is not required in the semi-purified diet developed for Macrobrachium rosenbergii when cultured under the experimental conditions of this study. The semi-purified diet formulated in this study would appear to be an adequate test diet to determine many of the qualitative and quantitative nutrient requirements of Macrobrachium rosenbergii. However, the best weight gain of the prawn was on a practical-type diet indicating that further refinement of the test diet formulation may be required.     

Effects of thyroid hormone supplementation of canola meal-based diets on growth,and interrenal and thyroid gland physiology of rainbow trout (Salmo gairdneri)

Rainbow trout fed a 26% canola meal-based (CM) diet for 12 weeks at 15°C exhibited reduced growth, lower feed conversion, enlarged thyroid glands and lower plasma thyroid hormone (TH) levels than comparable fish fed equinitrogenous, equicaloric soybean meal-based (SB) diets. Supplementation of the SB diets with either T₄ (20 mg/kg) or T₃ (10 or 20 mg/kg) had no effect on the growth rate, feed conversion and thyroid histology of the trout. However, plasma T₄ levels weredepressed in trout fed the T₄- and high T₃-supplemented SB diets. In trout fed T₄- and T3-supplemented CM diets the growth rates and feed conversion were not significantly different from those of the SB-fed groups. Moreover, in the T₄-supplemented group, plasma T₄ levels were in the normal range. However, thyroid enlargement was evident in all the CM-fed fish, and plasma T₃ levels were markedly elevated in groups fed the T₃-supplemented CM diets. The data suggest that antithyroid components in the CM diets inhibited TH synthesis (but not their release), and impaired TH clearance from the circulation. There were no significant differences in plasma cortisol levels in the 8 treatment groups, nor were there differences in the histological appearance of the interrenal gland. However, when the data from SB- and CM-fed fish were pooled, plasma cortisol levels in the SB-fed fish were significantly lower than in the CM-fed animals. Glucosinolates at a level of 164 mg/kg diet were toxic to young trout, but the effect was ameliorated by dietary TH supplementation.     

Dietary carbohydrate and growth,body composition and heat increment in rainbow trout (Salmo gairdneri)

A study was conducted to determine growth, body composition and heat increment (HI) of rainbow trout reared on isonitrogenous high digestible carbohydrate (HC) and high fat (HL) diets at 15°C. Trout reared on the HC diet had a significantly lower final body weight and carcass lipid content and a significantly higher feed:gain ratio and carcass protein content than trout reared on the HL diet after 12 weeks on the test diets. The lower carcass lipid composition indicates that trout do not readily convert dietary carbohydrates into fat. HI of trout reared on the HC diet was significantly higher than that of fish reared on the HL diet. Considering the poor utilization of dietary carbohydrates as an energy source and the apparently low conversion of dietary glucose into fat, the cause of the higher HI associated with the HC diet is not completely understood. However, it is possible the elimination of excess dietary glucose is an energy dependent process resulting in an increased heat production which would partly account for the increased HI. Furthermore, if the HC diet is a low net energy diet, then the metabolism and utilization of dietary and tissue proteins (amino acids) for energy by the trout may also be partly responsible for the increased HI of the trout reared on the HC diet.     

Proteomic analysis of temperature-dependent changes in stored UHT milk

Molecular changes in milk proteins during storage of UHT-treated milk have been investigated using two-dimensional electrophoresis (2-DE) coupled to MALDI-TOF mass spectrometry. UHT-treated samples were stored at three different temperatures, 4 °C, 28 °C, and 40 °C, for two months. Three main changes could be observed on 2-DE gels following storage. They were (1) the appearance of diffuse staining regions above the position of the monomeric caseins caused by nondisulfide cross-linking of α and β-caseins; (2) the appearance of additional acidic forms of proteins, predominantly of α(S1)-casein, caused by deamidation; and (3) the appearance of "stacked spots" caused by lactosylation of whey proteins. The extent of the changes increased with increased storage temperature. Mass spectrometric analysis of in-gel tryptic digests showed that the cross-linked proteins were dominated by α(S1)-casein, but a heterogeneous population of cross-linked forms with α(S2)-casein and β-casein was also observed. Tandem MS analysis was used to confirm deamidation of N(129) in α(S1)-casein. MS analysis of the stacked spots revealed lactosylation of 9/15 lysines in β-lactoglobulin and 8/12 lysines in α-lactalbumin. More extensive analysis will be required to confirm the nature of the cross-links and additional deamidation sites in α(S1)-casein as the highly phosphorylated nature of the caseins makes them challenging prospects for MS analysis.     

Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby

The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter.     

The effect of post‐harvest storage conditions on the development of black dot (Colletotrichum coccodes) on potato in crops grown for different durations

The effects of post‐harvest curing and storage temperature on severity of black dot, caused by Colletotrichum coccodes, were investigated for potato crops grown for different crop durations (days from 50% emergence to harvest) in soils that posed a low, medium and high risk of disease. In field trials over four growing seasons (2005–8), black dot severity at harvest increased with increasing crop duration, within the range 103–146 days from 50% emergence to harvest (P < 0.05). In field trials over three growing seasons (2006–8), black dot severity on tubers at harvest increased significantly with increasing soil inoculum in each year, within the range 43–4787 pg C. coccodes DNA/g soil (P < 0.05). Storage trials were conducted to measure the influence of accumulated post‐harvest temperature on black dot. In 2005, no difference in black dot severity was observed on tubers stored for 20 weeks at 2.5 and 3.5 °C. In 2006 (but not 2007), increasing the duration of curing after harvest from 4 to 14 days increased black dot severity on tubers from 8.9 to 11.2% (P < 0.01) in long duration crops (>131 days after 50% emergence) grown under high (>1000 pg C. coccodes DNA/g soil) soil inoculum. The number of days of curing did not affect disease severity for shorter duration crops grown at high soil inoculum, or on crops grown at medium or low (100–1000 and <100 pg C. coccodes DNA/g soil, respectively) soil inoculum concentrations. Soil inoculum and crop duration together provided a reasonable prediction of black dot severity at harvest and after a 20‐week storage period.     

NONINVASIVE ESTIMATION OF CENTRAL VENOUS PRESSURE IN ANESTHETIZED DOGS BY MEASUREMENT OF HEPATIC VENOUS BLOOD FLOW VELOCITY AND ABDOMINAL VENOUS DIAMETER

Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B‐mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B‐mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a‐, S‐ and v‐wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v‐wave velocity (0.823), S‐wave velocity (?0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v‐wave velocity (r=0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.     

Bragg diffraction from crystallized ion plasmas

Single crystals of a one-component plasma were observed by optical Bragg diffraction. The plasmas contained 10(5) to 10(6) single-positive beryllium-9 ions (9Be+) at particle densities of 10(8) to 10(9) per cubic centimeter. In approximately spherical plasmas, single body-centered cubic (bcc) crystals or, in some cases, two or more bcc crystals having fixed orientations with respect to each other were observed. In some oblate plasmas, a mixture of bcc and face-centered cubic ordering was seen. Knowledge of the properties of one-component plasma crystals is required for models of white dwarfs and neutron stars, which are believed to contain matter in that form.     

Relationship between cultivar height and severity of Fusarium ear blight in wheat

A significant negative relationship between tiller height and resistance to Fusarium ear blight (FEB), following inoculation, was observed in 17 cultivars of winter wheat in the 1995/96 growing season. Tall cultivars such as Kraka and Spark showed fewer symptoms of FEB (6 and 4%) than the shorter cultivars Brigadier and Virtue (35 and 51%). To determine if this relationship was caused by a genetic association or an effect of the microclimate, height and disease were measured in segregating populations derived from tall × short cultivars and humidity was measured in near-isogenic lines with and without the Rht1 and Rht2 dwarfing genes. Among random F₃ populations there was a clear tendency for tall strawed lines to show less severe disease symptoms than shorter strawed lines following inoculation. The effect of the individual dwarfing genes Rht1 and Rht2 on the severity of FEB was also studied in an inoculation trial using a number of near-isogenic lines of Maris Huntsman and Maris Widgeon. Within isogenic lines of Maris Huntsman, there was a clear tendency for tall straw to be associated with fewer symptoms, but this was not apparent within lines of Maris Widgeon. Monitoring relative humidity at ear height in a short and tall isogenic line of Maris Huntsman revealed no significant differences between these genotypes from GS 65 to GS 85, suggesting that microclimate cannot explain differences in severity of FEB between these lines. It is suggested that there are independent genes affecting the severity of FEB that may allow plant breeders to select resistant cultivars of any height.