Genetic analysis of body condition score in first-parity Danish Holstein cows

The aim of this study was to test whether genetic components for body condition score (BCS) changed during lactation in first-parity Danish Holsteins. Data were extracted from the national conformation scoring system and consisted of 28,948 records from 3894 herds. Cows were scored once during lactation for BCS on a scale from 1 to 9 with increments of 1. The majority of records were made from d 30 to 150 of lactation. Mean BCS was 4.28 +/- 0.98. Body condition score was lowest in wk 8 to 10 from calving. A multivariate sire model with BCS recordings in six lactation stages treated as different traits was used to analyze the data. In addition, a random regression sire model was used to evaluate the changes in BCS as continuous functions of lactation stage. Estimates of heritability from the multivariate approach ranged from 0.14 to 0.29, and the estimated genetic correlations between BCS at different lactation stages were all higher than 0.82. The random regression model was based on Legendre polynomials (LP) specified on days in milk at scoring. To evaluate the change in mean BCS during lactation, the fixed part of the model included a fifth-order LP on the effect of days in milk at scoring. The highest order of fit used for the sire effect was a third-order LP, but based on likelihood ratio tests this could be reduced to a 0 order, i.e., a model with only the intercept term for the sire effect. This means that the genetic variation is constant over the investigated part of the lactation. Therefore, BCS can be considered the same trait during lactation, and a simple sire model can be used for prediction of breeding values.     

Mobility of solutes in frozen pork studied by electron spin resonance spectroscopy evidence for two phase transition temperatures

The mobility of solutes in frozen pork (longissimus dorsi) was studied by X band electron spin resonance spectroscopy (ESR) using the three water soluble spin probes TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl), CAT 1 (4-trimethylammonium-2,2,6,6-tetramethylpiperidine-1-oxyl) and TEMPO choline (4-(N,N-dimethyl-N-(2-hydroxyethyl))ammonium-2,2,6,6-tetramethylpiperidine-1-oxyl). The mobility was quantified as the observed hyperfine coupling constant A'(zz). The three spin probes, of which only the neutral TEMPOL may penetrate membranes, gave very similar values of A'(zz) as a function of the temperature. A'(zz) was constant at temperatures below -55?°C, whereas A'(zz) decreased as the temperature was increased above -55?°C. This behavior has been interpreted as an increase in the amplitude of the rotational oscillations of the spin probes (and other solutes) with temperature. Above -13?°C the spin probes gave isotropic ESR spectra indicating free rotational mobility in a molten liquid phase. These results are discussed in relation to glass transitions in frozen pork.     

Expression of CA-125 by progestational bovine endometrium: prospective regulation and function

Cancer antigen 125 (CA-125) is expressed by malignant human ovarian surface epithelial cells and derivatives of the Müllerian duct system. This study explored the expression, regulation, and function of CA-125 in the bovine uterus. CA-125 was localized by immunohistochemistry to the apical surfaces of epithelial cells lining the endometrium and proximal glands of the late luteal phase and early pregnancy; antigen was not detected during oestrus or the postpartum period. Production of CA-125 by bovine endometrial cells in vitro was upregulated by progesterone and interferon-tau. Immunopurified CA-125 from uterine flushes of dioestrous or pregnant cows was similar in biochemical composition (as determined by gel electrophoresis and amino acid content) to the human antigen isolated from incubation medium conditioned by the ovarian cancer cell line OVCAR-3. Bovine CA-125 inhibited complement-induced lysis of antibody-sensitized sheep erythrocytes. It is suggested that endometrial CA-125 exerts a progestational role in part by protecting maternal and embryonic cells from immune targeting and lysis.     

Genetic divergence in cellular resistance to heat shock in cattle: differences between breeds developed in temperate versus hot climates in responses of preimplantation embryos,reproductive tract tissues and lymphocytes to increased culture temperatures

The detrimental effects of heat stress on fertility in cattle are less pronounced in heat-tolerant breeds. Although these genetic differences reflect differences in thermoregulation, cells from heat-tolerant breeds are less adversely compromised by increased temperature (that is, heat shock) than cells from heat-sensitive breeds. Experiments were performed to test the hypothesis that cells and tissues from two thermotolerant breeds (Brahman and Senepol) are better able to survive and function after exposure to increased temperature than cells and tissues from two thermosensitive breeds (Holstein and Angus). Exposure of embryos at>eight-cell stage at day 5 after insemination to heat shock of 41.0 degrees C for 6 h decreased development to the blastocyst stage and the number of cells per embryo. However, the deleterious effect of heat shock on blastocyst formation and the number of cells per embryo was less pronounced for Brahman than for Holstein and Angus breeds. Embryos from Senepol cows had very low development and it was not possible to determine heat shock effects in this breed. In contrast to the sensitivity of embryos to heat shock, there was no effect of a 41.0 degrees C heat shock on [(3)H]leucine incorporation into proteins secreted by oviductal or endometrial explants. Lymphocytes from Brahman and Senepol cows were more resistant to heat-induced apoptosis than lymphocytes from other breeds. Heat shock reduced lymphocyte glutathione content but the magnitude of the decrease was not affected by breed. In conclusion, embryos from Brahman cows are more resistant to heat shock than embryos from Holstein or Angus cows. Genetic differences are also present in thermotolerance for apoptosis response in lymphocytes, with Brahman and Senepol cattle being more resistant to heat shock than Angus and Holstein breeds. It is likely that the evolutionary forces that led to the Brahman and Senepol breeds being adapted to hot climates resulted in the selection of genes controlling resistance to cellular heat shock.     

Reconstruction and visualization of planetary nebulae

From our terrestrially confined viewpoint, the actual three-dimensional shape of distant astronomical objects is, in general, very challenging to determine. For one class of astronomical objects, however, spatial structure can be recovered from conventional 2D images alone. So-called planetary nebulae (PNe) exhibit pronounced symmetry characteristics that come about due to fundamental physical processes. Making use of this symmetry constraint, we present a technique to automatically recover the axisymmetric structure of many planetary nebulae from photographs. With GPU-based volume rendering driving a nonlinear optimization, we estimate the nebula's local emission density as a function of its radial and axial coordinates and we recover the orientation of the nebula relative to Earth. The optimization refines the nebula model and its orientation by minimizing the differences between the rendered image and the original astronomical image. The resulting model allows creating realistic 3D visualizations of these nebulae, for example, for planetarium shows and other educational purposes. In addition, the recovered spatial distribution of the emissive gas can help astrophysicists gain deeper insight into the formation processes of planetary nebulae.     

Universal approach for selective trace metal determinations via sequential injection-bead injection-lab-on-valve using renewable hydrophobic bead surfaces as reagent carriers

A new concept is presented for selective and sensitive determination of trace metals via electrothermal atomic absorption spectrometry based on the principle of bead injection (BI) with renewable reversed-phase surfaces in a sequential injection-lab-on-valve (SI-LOV) mode. The methodology involves the use of poly(styrene-divinylbenzene) beads containing pendant octadecyl moieties (C18-PS/DVB), which are preimpregnated with a selective organic metal chelating agent prior to the automatic manipulation of the beads in the microbore conduits of the LOV unit. By adapting this approach, the immobilization of the most suitable chelating agent can be effected irrespective of the kinetics involved, optimal reaction conditions can be used for implementing the chelating reaction of the target metal analyte with the immobilized re-agent, and an added degree of freedom is offered in selecting the most favorable elution mode in order to attain the highest sensitivity. The potential of the SI-BI-LOV scheme is demonstrated by taking Cr(VI) as a model analyte, using a 1,5-diphenylcarbazide (DPC)-loaded bead column as the active microzone. As this reaction requires the use of high acidity, it is also shown that the bead material exhibits excellent chemical stability at low pH values. On-line pH sample adjustment prevents alteration of the original distribution of chromium species while ensuring fast rates for the DPC-Cr(VI) reaction. The proposed procedure was successfully applied to the determination of trace levels of Cr(VI) in natural waters containing high levels of dissolved salts (such as seawater and hard tap water) without requiring any dilution step. Method validation was performed by determination of total chromium in an NIST standard reference material (NIST 1640, natural water) after Cr(III) oxidation, and the results were in good agreement with the certified value.     

Electrodialytic remediation of copper mine tailings

Mining activities in Chile have generated large amounts of solid waste, which have been deposited in mine tailing impoundments. These impoundments cause concern to the communities due to dam failures or natural leaching to groundwater and rivers. This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2 V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4, and the copper by this reason was released in the solution. Furthermore, with acidic tailing the potential gradient was less than 2 V/cm. The maximum copper removal reached in the anode side was 53% with addition of sulphuric acid in 21 days experiment at 20 V using approximately 1.8 kg mine tailing on dry basis. In addition, experiments with acidic tailing show that the copper removal is proportional with time.     

Comparison of methods for assessing reverse osmosis membrane treatment of shrimp process water

Interest in reuse of process water from the food industry has reinforced the importance of controlling and monitoring the effectiveness and reliability of treatment systems regarding removal of organic matter and microorganisms. The ability of adenosine triphosphate bioluminescence, conductivity, turbidometry, absorbance, and multichannel fluorescence spectroscopy for indirectly monitoring the integrity of a reverse osmosis membrane when treating process water recovered from peeling in a shrimp processing line was evaluated. This study demonstrated that reverse osmosis was capable of removing bacteria (ca. 7 log CFU ml(-1)) to the levels required by the regulatory authorities for water recycling within the same food unit operation. Adenosine triphosphate and turbidometry showed a higher sensitivity for detecting compromising conditions at the treatment system (0.1% concentration of feed in permeate) and a better correlation with the aerobic count at lower levels than the other methods investigated. The sensitivity for assessing membrane integrity of conductivity and multichannel fluorescence was 1% of feed in permeate. Impact of feed variations was best leveled out in the permeates for turbidity measurements. Multichannel fluorescence spectroscopy may require laborious calibration procedures and expertise regarding data analysis and interpretation of results, which are not always available in food industries. Absorbance did not respond to changes in membrane integrity and was not well correlated to the aerobic count because of the poor sensitivity of this method for these purposes.     

GAP1, a novel selection and counter-selection marker for multiple gene disruptions in Saccharomyces cerevisiae

We report on the use of a new homologous marker for use in multiple gene deletions in S. cerevisiae, the general amino acid permease gene (GAP1). A GAP1 strain can utilize L-citrulline as the sole nitrogen source but cannot grow in the presence of the toxic amino acid D-histidine. L-citrulline as well as D-histidine uptake is mediated solely by the general amino acid permease, and a gap1 strain is therefore able to grow in the presence of D-histidine but cannot utilize L-citrulline. Gene disruption is effected by transforming a gap1 strain with a gene cassette generated by PCR, containing GAP1 flanked by short (60 bp) stretches of the gene in question. Through homologous recombination, the cassette will integrate into the target gene, which is thus replaced by GAP1, and mutants are selected for on minimal L-citrulline medium. When propagated under non-selective conditions, some cells will lose the GAP1 gene. This is caused by recombination between two Ashbya gossypii AgLEU2 [corrected] direct repeats embracing GAP1, and will result in a sub-population of gap1 cells. Such cells are selected on a medium containing D-histidine, and may subsequently be used for a second gene disruption. Hence, multiple gene disruptions can be made fast, cheaply and easily in a gap1 strain, with two positive selection steps for each disruption.