Saccadic latency in hepatic encephalopathy: a pilot study

Hepatic encephalopathy is a common complication of cirrhosis. The degree of neuro-psychiatric impairment is highly variable and its clinical staging subjective. We investigated whether eye movement response times—saccadic latencies—could serve as an indicator of encephalopathy. We studied the association between saccadic latency, liver function and paper- and pencil tests in 70 patients with cirrhosis and 31 patients after liver transplantation. The tests included the porto-systemic encephalopathy (PSE-) test, critical flicker frequency, MELD score and ammonia concentration. A normal range for saccades was established in 31 control subjects. Clinical and biochemical parameters of liver, blood, and kidney function were also determined. Median saccadic latencies were significantly longer in patients with liver cirrhosis when compared to patients after liver transplantation (244 ms vs. 278 ms p < 0.001). Both patient groups had prolonged saccadic latency when compared to an age matched control group (175 ms). The reciprocal of median saccadic latency (μ) correlated with PSE tests, MELD score and critical flicker frequency. A significant correlation between the saccadic latency parameter early slope (σE) that represents the prevalence of early saccades and partial pressure of ammonia was also noted. Psychometric test performance, but not saccadic latency, correlated with blood urea and sodium concentrations. Saccadic latency represents an objective and quantitative parameter of hepatic encephalopathy. Unlike psychometric test performance, these ocular responses were unaffected by renal function and can be obtained clinically within a matter of minutes by non-trained personnel

On transmissible load formulations in topology optimization

Transmissible loads are external loads defined by their line of action, with actual points of load application chosen as part of the topology optimization process. Although for problems where the optimal structure is a funicular, transmissible loads can be viewed as surface loads, in other cases such loads are free to be applied to internal parts of the structure. There are two main transmissible load formulations described in the literature: a rigid bar (constrained displacement) formulation or, less commonly, a migrating load (equilibrium) formulation. Here, we employ a simple Mohr’s circle analysis to show that the rigid bar formulation will only produce correct structural forms in certain specific circumstances. Numerical examples are used to demonstrate (and explain) the incorrect topologies produced when the rigid bar formulation is applied in other situations. A new analytical solution is also presented for a uniformly loaded cantilever structure. Finally, we invoke duality principles to elucidate the source of the discrepancy between the two formulations, considering both discrete truss and continuum topology optimization formulations

Effect of maternally-derived antibodies on the performance and immunity of broilers induced by in ovo or post-hatching immunizations with a live vaccine against infectious bursal disease

The interference of low or high maternal antibodies titers on the attenuated infectious bursal disease (IBD) virus (IBDV) vaccine infection and its effects on the performance of broilers vaccinated at the 18th day of incubation (in ovo), at one day of age (subcutaneously-SC), or at 15 days of age (drinking water-DW) were investigated. After a series of three live vaccinations, breeders were given or not an IBD oil emulsion vaccine (IBD-OEV) prior to sexual maturity. At day 18 of incubation (in ovo), a commercial vaccine containing HVT and an intermediate IBDV strain or the single HVT vaccine was given. An intermediate IBDV vaccine was given SC at one day of age, or at 15 days of age via DW. The progeny of unvaccinated breeders presented higher neutralizing IBDVspecific antibody (IBDVab) titers at 25 and 40 days of age than those of the progeny of IBD-OEV breeders (p<0.05) at any broilers vaccination age and route. The lower IBDV RNA detection by RT-PCR in the bursa of Fabricius (BF) and the lower IBDV antibody titers in the serum of the groups vaccinated at one and 15 days of age derived from IBD-OEV breeders may indicate antibody-mediated IBDV neutralization. The inovo and one-day vaccinations did not interfere with performance, both in low and high antibody-titered progenies. The in-ovo vaccination against IBD is considered convenient and safe for industrial chickens, irrespective their maternal antibody levels