Work schedule differences in sleep problems of nursing home caregivers

Nursing home caregivers (n=775; 604 women; mean age 33.6 years) were studied to examine how work schedules affect their sleep. The shift group (n=536) worked under a rotating two-shift system (n=365), a rotating three-shift system (n=66), or other types of shifts (n=78). The non-shift group included 222 caregivers. Participants completed a questionnaire about working conditions, sleep problems, health, lifestyle, and demographic factors. The two-shift caregivers reported the highest levels of difficulty initiating sleep (DIS, 37.6%), insomnia symptoms (43.0%), and poor quality of sleep (24.9%) among the groups. Adjusted odds ratios for these problems were significantly greater for the two-shift caregivers than for non-shift counterparts: DIS (odds ratio 2.86, 95% confidence interval 1.57-5.20), insomnia symptoms (2.33, 1.36-4.02), and poor sleep quality (2.15, 1.09-4.22). Our data suggest that working under a rotating two-shift system, which has a longer night shift, is associated with an elevated risk of sleep problems for nursing home caregivers.     

Adaptive immunity based reinforcement learning

Recently much attention has been paid to intelligent systems which can adapt themselves to dynamic and/or unknown environments by the use of learning methods. However, traditional learning methods have a disadvantage that learning requires enormously long amounts of time with the degree of complexity of systems and environments to be considered. We thus propose a novel reinforcement learning method based on adaptive immunity. Our proposed method can provide a near-optimal solution with less learning time by self-learning using the concept of adaptive immunity. The validity of our method is demonstrated through some simulations with Sutton’s maze problem. This work was present in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Oxygen potentials of (U,Gd)O2 ± x solid solutions in the temperature range 1000–1500°C

Oxygen potentials of U_0.86Gd_0.14O_{2 ± x} and U_0.73Gd_0.27O_{2 ± x} solid solutions, together with UO_{2 ± x}, have been measured at 1000, 1300 and 1500°C by using a thermogravimetric technique. The results at 1000°C show good agreement with the results of a previous solid electrolyte galvanic cell measurement. The oxygen potentials for the solid solutions increase positively with increasing Gd content. Stable hypostoichiometric phases are seen at the oxygen potentials below ?65 and ?50 kcal/mol between 1000 and 1500°C for U_0.86Gd_0.14O₂ and U_0.73Gd_0.27O₂, respectively. From the oxygen partial pressure dependence of x, models for the defect structure in hyper- and hypostoichiometric solid solutions are suggested.     

Deep MAnTra: deep learning-based multi-animal tracking for Japanese macaques

Artificial Life and Robotics - Multi-instance object tracking is an active research problem in computer vision, where most novel methods analyze and locate targets on videos taken from static...     

Hepatocyte growth factor enhances the invasion activity of human hepatocellular carcinoma cell lines

The mouse recessive deafness mutation, shaker-2(sh-2), represents a plausible model for an autosomal recessive form of human non-syndromic genetic deafness, DFNB3. Here we report the use of a positional cloning approach to show that the gene mutated in sh-2 mice encodes a novel type of unconventional myosin. A G-to-A transition changing cysteine to tyrosine in the conserved actin binding domain is detected in sh-2 but absent in laboratory strains and wild mice belonging to different mouse subspecies and species. This suggests that the novel myosin gene is a strong candidate for DFNB3.     

Geometrical properties of nu support vector machines with different norms

By employing the L1 or Linfinity norms in maximizing margins, support vector machines (SVMs) result in a linear programming problem that requires a lower computational load compared to SVMs with the L2 norm. However, how the change of norm affects the generalization ability of SVMs has not been clarified so far except for numerical experiments. In this letter, the geometrical meaning of SVMs with the Lp norm is investigated, and the SVM solutions are shown to have rather little dependency on p.     

Dynamics of iron-ascorbate-induced lipid peroxidation in charged and uncharged phospholipid vesicles

Peroxidation of egg yolk phosphatidylcholine (egg PC) liposomes was induced by addition of ascorbic acid (AsA) and Fe(II) in the presence of a trace of autoxidized egg PC (PC−OOH), but not in the absence of PC−OOH. PC−OOH was degraded upon addition of AsA and Fe(II) but not of either one alone. The results suggest that PC−OOH is necessary to initiate lipid peroxidation by AsA/Fe(II). AsA oxidation in the bulk water phase was also associated with an increase in lipid peroxidation by AsA/Fe(II) in the presence of PC−OOH, but not in the absence of PC−OOH. Furthermore, the spin probe 12-NS [12-(N-oxyl-4,4′-dimethyloxazolidin-2-yl)stearic acid], which labels the hydrophobic region of dimyristoyl phosphatidylcholine (DMPC) liposomal membranes, was degraded upon addition of AsA and Fe(II) in the presence of PC−OOH, but not in the absence of PC−OOH. These results indicate that the “induction message” that is associated with decreases of PC−OOH and AsA in the initiation step of lipid peroxidation must be transferred from the membrane surface to the inner hydrophobic membrane region. AsA in the bulk phase was oxidized faster and more extensively upon its addition together with Fe(II) to egg PC liposomes than to DMPC liposomes, though the initial content of PC−OOH in the former was 5–10 times lower than in the latter. This suggests that, in egg PC liposomes, the OOH-groups of new PC−OOH generated in the inner membrane regions must become accessible from the surface, enabling reaction with AsA/Fe(II) which in turn would result in an extensive decrease in AsA. By contrast, in DMPC liposomes, that do not generate PC−OOH, AsA is only oxidized slightly in connection with the degradation of the PC−OOH initially present. The effect of surface charges on the membrane surface was also studied to obtain further information on the initiation step of lipid peroxidation. The rate of lipid peroxidation by AsA/Fe(II) or Fe(III) decreased in the order, egg PC liposomes ≫negatively charged egg PC liposomes containing dicetylphosphate>positively charge egg PC liposomes containing stearylamine. The rate of associated AsA oxidation was in the order, egg PC liposomes≫egg PC/stearylamine liposomes>egg PC/dicetylphosphate liposomes. However, in DMPC liposomes that do not generate PC−OOH, the rates of AsA oxidation associated with the reductive cleavage of PC−OOH by AsA/Fe(II) and coupled with the reduction of Fe(III) to Fe(II) were in the order, DMPC liposomes =DMPC/stearylamine liposomes≫DMPC/dicetylphosphate liposomes. These differences in the rates of lipid peroxidation, depending on differences in membrane charge, are discussed in relation to two properties of AsA: (i) its antioxidant property through trapping of lipid radicals and (ii) its prooxidant properties (a) by being an effective iron chelator thus altering the reactivity of iron with oxygen and peroxides and (b) by being an iron reductant and providing a source of Fe(II).