Colour of fat,and colour,fatty acid composition and sensory characteristics of muscle from heifers offered alternative forages to grass silage in a finishing ration

The effect of type of silage offered to beef heifers during the finishing period on aspects of beef quality was determined. In two experiments, a diet based on grass silage (GS) was compared with a diet based on maize silage (MS) or whole-crop wheat silage (WCW). Compared to the GS-based diet, increasing the amount of MS linearly increased fat whiteness while the increase in fat whiteness due to WCW was dependent on the stage of crop maturity at harvesting. There was no effect of diet on muscle colour or on muscle pH measured at 48 h post-mortem, drip loss, taste panel traits after 14 days ageing or shear force values at 2, 7 or 14 days ageing. The alternative silages decreased the n − 3 polyunsaturated fatty acid proportion and increased the linoleic:linolenic acid ratio in intramuscular lipid. It is concluded that type of silage affects fat colour and fatty acid composition of muscle but not the other muscle characteristics examined.     

The GIF Quantum,a next generation post-column imaging energy filter

We describe a new post-column imaging energy filter for (scanning) transmission electron microscopy from 60 to 300 kV operating voltage. The completely redesigned GIF quantum has a gradient magnetic prism, dodecapole optics, a 10-times faster 40 Mpixel/sec CCD camera, a 1 μs electrostatic shutter, and new user interface, control, and auto-alignment software. An 8 dodecapole lens system, performs full 2nd and 3rd, and partial 4th and 5th order aberration correction. The improved aberration correction has allowed the size of the entrance aperture to be nearly doubled to 9.0 mm compared to current generation post-column designs. The electrostatic shutter provides exposure control down to 1 μs, extending the exposure time range to over 7 orders of magnitude. Spectroscopy operation has been improved with a larger 2 keV field of view at 200 kV, and a maximum acquisition rate of 1000 spectra per second. A high-speed DualEELS mode simultaneously acquires core- and low-loss spectra up to 2 keV apart. A more intuitive user interface includes new capabilities such as automated exposure control and optimized full spectrum acquisition. The auto-alignment software has been significantly enhanced to use the full flexibility of the dodecapole lens system.     

A 3.6-Gb/s point-to-point heterogeneous-voltage-capable DRAM interface for capacity-scalable memory subsystems

We describe a DRAM interface operating at 3.6 Gb/s/pin implemented in 130-nm CMOS logic and 110-nm DRAM process technologies. It utilizes simultaneous bidirectional (SBD) signaling in a daisy-chained (repeated), point-to-point configuration to enable high performance scalable memory subsystems; and also provides direct attach capability for DRAMs to memory controllers or other logic devices. Source-synchronous strobes are used for data capture, minimizing strobe-to-data jitter. A low-jitter differential clock retimes the data at each DRAM on a per DIMM basis preventing jitter from accumulating in repeated data. The phase of this clock is adjusted on each DRAM to minimize the latency of the repeaters. 80 mW of total power is dissipated per DRAM I/O at 3.6 Gb/s. We present results from a system using both memory controller and DRAM repeater test chips.     

Uptake by rat liver and intracellular fate of plasmid DNA complexed with poly-L-lysine or poly-D-lysine

Adding normal saline (NS) separately before 99Tcm-sodium pertechnetate to MDP cold kits has been shown to reduce substantially the radiation dose to the hand. A similar dose reduction will probably prove to be valid with the preparation of most other 99Tcm-labelled radiopharmaceuticals. However, it is unknown how this altered reconstitution procedure may affect the labelling efficiency and in vitro stability of the 99Tcm-labelled radiopharmaceuticals. We have evaluated the effects on the labelling efficiency and in vitro stability of 99Tcm-labelled MDP, mertiatide and sestamibi reconstituted with three different methods: adding normal saline before 99Tcm activity (NS/Tc); adding 99Tcm activity before normal saline (Tc/NS); and the standard reconstitution method of adding both 99Tcm activity and normal saline together. The labelling efficiency and in vitro stability were evaluated by measuring the radiochemical purity of each radiopharmaceutical tested at 0, 1, 3, 6, 12 (except 99Tcm-MDP) and 24 h after reconstitution. For 99Tc-mertiatide, there was a very slight difference in the labelling efficiency, mostly due to the Tc/NS method being approximately 0.29% lower across time post-reconstitution than the standard method. For 99Tcm-labelled MDP and sestamibi, there were no differences between the three methods in terms of labelling efficiency and in vitro stability. In conclusion, both alternative methods (i.e. NS/Tc and Tc/NS) appear not to have any detrimental effect on the labelling efficiency and in vitro stability of the 99Tcm-labelled radiopharmaceuticals that we tested. However, of the two alternative kit reconstitution methods, we recommend the NS/Tc method, since it may reduce the hand radiation dose.     

The importance of coulombic end effects: experimental characterization of the effects of oligonucleotide flanking charges on the strength and salt dependence of oligocation (L8+) binding to single-stranded DNA oligomers

Binding constants Kobs, expressed per site and evaluated in the limit of zero binding density, are quantified as functions of salt (sodium acetate) concentration for the interactions of the oligopeptide ligand KWK6NH2 (designated L8+, with ZL = 8 charges) with three single-stranded DNA oligomers (ss dT-mers, with |ZD| = 15, 39, and 69 charges). These results provide the first systematic experimental information about the effect of changing |ZD| on the strength and salt dependence of oligocation-oligonucleotide binding interactions. In a comparative study of L8+ binding to poly dT and to a short dT oligomer (|ZD| = 10),. Proc. Natl. Acad. Sci. USA. 93:2511-2516) demonstrated the profound thermodynamic effects of phosphate charges that flank isolated nonspecific L8+ binding sites on DNA. Here we find that both Kobs and the magnitude of its power dependence on salt activity (|SaKobs|) increase monotonically with increasing |ZD|. The dependences of Kobs and SaKobs on |ZD| are interpreted by introducing a simple two-state thermodynamic model for Coulombic end effects, which accounts for our finding that when L8+ binds to sufficiently long dT-mers, both DeltaGobso = -RT ln Kobs and SaKobs approach the values characteristic of binding to poly-dT as linear functions of the reciprocal of the number of potential oligocation binding sites on the DNA lattice. Analysis of our L8+-dT-mer binding data in terms of this model indicates that the axial range of the Coulombic end effect for ss DNA extends over approximately 10 phosphate charges. We conclude that Coulombic interactions cause an oligocation (with ZL < |ZD|) to bind preferentially to interior rather than terminal binding sites on oligoanionic or polyanionic DNA, and we quantify the strong increase of this preference with decreasing salt concentration. Coulombic end effects must be considered when oligonucleotides are used as models for polyanionic DNA in thermodynamic studies of the binding of charged ligands, including proteins.     

Testicular suture: a significant risk factor for infertility among formerly cryptorchid men

BACKGROUND/PURPOSE: Although fertility is decreased after cryptorchidism, the importance of risk factors, including parenchymal testicular suture, is unknown. The aim of this study was to examine the relationship between parenchymal testicular suture and failure to conceive a child for 1 year or longer among formerly cryptorchid men. METHODS: Men who underwent orchidopexy between 1955 and 1972 at the Children's Hospital of Pittsburgh (n = 619) were surveyed by questionnaire and their medical records reviewed. Only the men who attempted to conceive a child (n = 387) are included. RESULTS: Logistic regression analysis determined significant risk factors for infertility. Testicular suture was strongly related to infertility (RR, 7.56; 95% CI, 1.66, 34.39) as were bilateral cryptorchidism (RR, 5.51; 95% CI, 1.58, 19.24), varicocele (RR, 4.72; 95% CI, 1.42, 15.75), hormone treatment before surgery (RR, 3.69; 95% CI, 1.22, 11.11), and partner conception problem (RR, 3.32; 95% CI, 1.11, 9.90). CONCLUSIONS: Testicular suture was a potent independent determinant of infertility among formerly cryptorchid men who have orchidopexy. Bilateral cryptorchidism, hormone treatment, varicocele, and partner conception problems also were associated with increased infertility.     

Cancer chemoprevention. A new way to treat cancer before it happens

Cancer chemoprevention uses noncytotoxic drugs or nutrients to prevent, retard, or delay carcinogenesis. The future of cancer chemoprevention depends on understanding key cellular growth and proliferation-controlling events, developing markers of molecular carcinogenesis, surrogate endpoint biomarkers, and targeted chemopreventive approaches.     

Chromosomal fragile sites and DNA amplification in drug-resistant cells

Halogenated aromatic hydrocarbons (HAHs), such as polychlorinated biphenyls (PCBs) and dibenzo-p-dioxins (PCDDs), alter cognitive function and learning. The cellular basis of HAH-induced alteration of brain function is not well-understood. The hippocampus is a likely site of toxic action because of its well-known roles in learning and memory, as well as its propensity to accumulate environmental neurotoxicants. A hippocampal function that can be measured readily is evoked excitatory postsynaptic potentials (EPSPs), which are an index of excitatory synaptic function. In this study, effects of HAHs on EPSPs were characterized in hippocampal slices from adolescent to adult male Sprague-Dawley rats. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and 1,2,3,4-TCDD were used because these HAHs are prototypical potent and weak aryl hydrocarbon (Ah) receptor agonists, respectively. 2,2',5,5'-Tetrachlorobiphenyl (TCB) was used as a prototypical ortho-substituted PCB, which acts through Ah receptor-independent pathways. For each hippocampal slice, peak amplitudes of EPSPs during a 15-min recording period (1 recording/min) were averaged and used as baseline (100%). Subsequent EPSPs were expressed as percentage of baseline. TCDD and 1,2,3,4-TCDD did not alter EPSPs in slices from the middle third of the hippocampus. However, in ventral slices, TCDD significantly decreased EPSPs, whereas 1,2,3,4-TCDD was inactive. TCB decreased EPSPs in both middle and ventral slices at half-maximal stimulation. An unexpected reversal of inhibition was observed within 30 min of continuous application of TCDD or TCB. In ventral slices, L-type calcium channel blocker nifedipine blocked inhibition of EPSPs induced by TCDD but not EPSPs inhibited by TCB. These results suggest that, while TCB-induced inhibition of EPSPs occurs through an unknown mechanism, TCDD-induced inhibition of EPSPs was mediated by L-type calcium channel activity in a congener-specific manner.     

Three-dimensional reconstruction techniques applied to intracoronary images

In recent years, systems for the three-dimensional (3-D) reconstruction of intravascular ultrasound (IVUS) images have been developed. As a major advantage over conventional two-dimensional IVUS, 3-D IVUS offers longitudinal views of the reconstructed segments and provide more comprehensive insight into the spatial distribution of vascular structures. The present article is an overview of current 3-D reconstruction techniques. In particular, we discuss the sequence of basic steps required to obtain a 3-D reconstruction: IVUS image acquisition, digitization, segmentation and reconstruction. We also illustrate the different systems of 3-D reconstruction that are currently available. Some of them can be used on-line during surgical procedures, while others are more suited for off-line applications and are useful research tools.