Orientational Correlations in Active and Passive Nematic Defects.

We investigate the emergence of orientational order among +1/2 disclinations in active nematic liquid crystals. Using a combination of theoretical and experimental methods, we show that +1/2 disclinations have short-range antiferromagnetic alignment, as a consequence of the elastic torques originating from their polar structure. The presence of intermediate -1/2 disclinations, however, turns this interaction from antialigning to aligning at scales that are smaller than the typical distance between like-sign defects. No long-range orientational order is observed. Strikingly, these effects are insensitive to material properties and qualitatively similar to what is found for defects in passive nematic liquid crystals.

Prevalence of Listeria monocytogenes in ready-to-eat foods sampled from the point of sale in Wales, United Kingdom.

A survey of Listeria in ready-to-eat food took place in Wales, United Kingdom, between February 2008 and January 2009. In total, 5,840 samples were taken and examined for the presence of Listeria species, including L. monocytogenes. Samples were tested using detection and enumeration methods, and the results were compared with current United Kingdom guidelines for the microbiological quality of ready-to-eat foods. The majority of samples were negative for Listeria by both direct plating and enriched culture. Seventeen samples (0.29%) had countable levels of Listeria species (other than L. monocytogenes), and another 11 samples (0.19%) had countable levels of L. monocytogenes. Nine samples (0.15%) were unsatisfactory or potentially hazardous when compared with United Kingdom guideline limits; six (0.10%) were in the unsatisfactory category (>100 CFU/g) for Listeria species (other than L. monocytogenes), and three (0.05%) were in the unacceptable or potentially hazardous category (>100 CFU/g) for L. monocytogenes. All three of these samples were from sandwiches (two chicken sandwiches and one ham-and-cheese sandwich). The most commonly isolated serotype of L. monocytogenes was 1/2a. This survey was used to determine the current prevalence of Listeria species and L. monocytogenes in ready-to-eat foods sampled from the point of sale in Wales.

Effect of heparin modeling on delivered hemodialysis therapy.

Heparin anticoagulation is standard practice in hemodialysis. To assess the effect of adequate heparinization on dialysis delivery, 28 chronic dialysis patients (mean age, 55 +/- 17 years; 18 men, 10 women) were selected for heparin modeling (HM). Polysulfone dialyzers were used. The dialysis prescription was kept unchanged, and an automated nonbleach reuse procedure was used. Measurements of time average concentration of urea (TACurea), KT/V delivered, normalized protein catabolic rate (nPCR), hematocrit, and dialyzer total blood compartment volumes [TBCVs] (fiber bundle volume [FBV] + header volume) were evaluated before and after heparin dosages were changed as indicated by HM. Heparin dosage increased from 2,400 +/- 841 IU to 4,398 +/- 3,112 IU (P < 0.002). While there was no significant change in nPCR (pre 0.84 +/- 0.34 v post 0.83 +/- 0.30), the effective clearance as measured by urea clearance improved from 212.8 +/- 37 to 240.1 +/- 49 mL/min (P < 0.05), KT/V remained unchanged, and TACurea decreased from 48.8 +/- 22.3 to 35.8 +/- 21.5 mg/dL (P < 0.05). Dialyzer TBCVs were unchanged (from 116 +/- 17 to 114 +/- 17 mL, NS). We conclude that the use of an appropriate dose of heparin during hemodialysis will improve polysulfone dialyzer clearance, increase the delivered KT/Vurea, and reduce TACurea. Heparin dosing should be given close attention because it does affect the dialysis dose delivered.

Comparison of two methods of kinetic modeling.

Kinetic modeling has been shown to be beneficial for a number of reasons in the dialysis population. It is useful as a quality control measure of dialysis, with a critical review of individual dialysis conditions; and it provides quantification for evaluation and change of treatment prescriptions allowing cost-saving reduction of treatment times. Kinetic modeling also provides objective patient and staff education with objective nutritional surveillance and improved patient compliance. A comparison of the results from UKM and DDQ for 40 simultaneously modeled patients showed statistically significant differences in pool volume, protein catabolic rate and dialyzer clearance with UKM yielding a higher mean in each case. Pool volumes obtained in DDQ compared more favorably to those obtained by separate calculations based on sex, age, height and weight, indicating greater accuracy in DDQ. This is partly because in DDQ solute removal is measured directly and rigid control of the dialysis process is not required. DDQ is a more accurate, flexible model which provides both an understanding of each individual's dialysis treatment and protein nutriture, thereby improving patient care.