Visual adjustments to temporal blur

After observers have adapted to an edge that is spatially blurred or sharpened, a focused edge appears too sharp or blurred, respectively. These adjustments to blur may play an important role in calibrating spatial sensitivity. We examined whether similar adjustments influence the perception of temporal edges, by measuring the appearance of a step change in the luminance of a uniform field after adapting to blurred or sharpened transitions. Stimuli were square-wave alternations (at 1 to 8 Hz) filtered by changing the slope of the amplitude spectrum. A two-alternative-forced-choice task was used to adjust the slope until it appeared as a step change, or until it matched the perceived transitions in a reference stimulus. Observers could accurately set the waveform to a square wave, but only at the slower alternation rates. However, these settings were strongly biased by prior adaptation to filtered stimuli, or when the stimuli were viewed within temporally filtered surrounds. Control experiments suggest that the latter induction effects result directly from the temporal blur and are not simply a consequence of brightness induction in the fields. These results suggest that adaptation and induction adjust visual coding so that images are focused not only in space but also in time.     

Metals in recycled polyethylene terephthalate and discrimination method for its use

Metals in recycled polyethylene terephthalate (PET) were analyzed by ICP-MS following microwave digestion with nitric acid. Physically and superclean-like recycled PET contained both Ge and Sb, and sometimes contained Co, P or Si. In contrast, the chemically recycled PET contained only Ge or Sb, and some samples contained Co. The recycled PETs did not contain Pb or Cd. Ge and Sb were catalysts of the polymerization, and the other metals also originated from the PET resin as additives. It was concluded that there is no safety concern about metals in recycled PET. It became clear that the presence of both Ge and Sb could identify products formed using physically or superclean-like recycled PET. According to this discrimination method, about half of the sheet molding products used recycled PET.     

Contrasting diurnal variations in fossil and nonfossil secondary organic aerosol in urban outflow, Japan

Diurnal variations of fossil secondary organic carbon (SOC) and nonfossil SOC were determined for the first time using a combination of several carbonaceous aerosol measurement techniques, including radiocarbon (1?C) determinations by accelerator mass spectrometry, and a receptor model (chemical mass balance, CMB) at a site downwind of Tokyo during the summer of 2007. Fossil SOC showed distinct diurnal variation with a maximum during daytime, whereas diurnal variation of nonfossil SOC was relatively small. This behavior was reproduced by a chemical transport model (CTM). However, the CTM underestimated the concentration of anthropogenic secondary organic aerosol (ASOA) by a factor of 4-7, suggesting that ASOA enhancement during daytime is not explained by production from volatile organic compounds that are traditionally considered major ASOA precursors. This result suggests that unidentified semivolatile organic compounds or multiphase chemistry may contribute largely to ASOA production. As our knowledge of production pathways of secondary organic aerosol (SOA) is still limited, diurnal variations of fossil and nonfossil SOC in our estimate give an important experimental constraint for future development of SOA models.     

Determination of substances in polylactic acid products for food-contact use and mutagenicity of their migration solutions

Specification tests defined in the Japanese Food Sanitation Law were conducted on 7 polylactic acid food-contact products. Moreover, the content and migration of other compounds were examined by means of ICP-AES, GC/MS and mutagenicity tests. All products met their specifications, and migration levels of heavy metals were negligible. No notable peak was observed in GC/MS analysis. Moreover, all products gave negative results in both rec-assay and the umu-test. An increase in the β-galactosidase activity in the umu-test observed with the migration solution of soup bowl was due not to polylactic acid, but to the polyurethane coating.     

Fabrication of single-wall carbon nanotubes within the channels of a mesoporous material by catalyst-supported chemical vapor deposition

Diameter-controlled single-wall carbon nanotubes (SWCNTs) have been synthesized using Co, Fe/Co and Rh/Pd alloy nanoparticles trapped within the one-dimensional channels of a mesoporous materials (Folded Sheets Mesoporous material: FSM-16) by catalyst-supported chemical vapor deposition (CCVD) using ethanol as carbon source at 973-1173 K. The SWCNTs synthesized are characterized by transmission electron microscopy, Raman spectroscopy and photoluminescence spectroscopy. The yield, diameter distribution and quality of the SWCNTs strongly depend on the reaction temperature during CCVD. The product synthesized at 1173 K contains only SWCNTs, in marked contrast to those synthesized at lower temperatures. As the reaction temperature decreases, the relative abundance of multi-wall carbon nanotubes against SWCNTs significantly increases, whereas the mean diameter of SWCNTs increases as reaction temperature increases. The results show that a careful control of the reaction temperature is crucial to fabricate diameter-controlled SWCNTs from the channels of FSM-16.     

Outstanding Toughness of Cherry Bark Achieved by Helical Spring Structure of Rigid Cellulose Fiber Combined with Flexible Layers of Lipid Polymers

Cellulose, a main component of cell walls, generally makes materials hard and brittle. However, an ultratough, cellulosic material is found in nature: cherry bark. Surprisingly, it elongates by more than twice of its initial length and behaves as a plastic film during stretching. This amazing mechanical property is achieved by a well‐designed cell wall structure; cellulose fibers are folded like helical springs, covered by multiple flexible layers of lipid polymers.     

Copper-Alkali Ion Exchange of Alkali Aluminosilicate Glasses in Molten CuCl—An Ion Exchange Controlled by the Cu+→Cu2+ Oxidation Reaction in Glass

The kinetics of copper-potassium ion exchange of potassium aluminosilicate glass have been investigated in molten CuCl at 550°C in air and nitrogen. The presence of oxygen dissolved in molten CuCl has a great effect on the Cu-K ion-exchange kinetics, i.e. ion exchange in nitrogen is controlled by the interdiffusion process of Cu⁺ and K⁺ in the glass, whereas ion exchange in air seems to be controlled by the Cu⁺→Cu²⁺ oxidation reaction.     

A case-control study of the association between urinary cadmium concentration and endometriosis in infertile Japanese women

Cadmium may act like an estrogen and be a potential risk factor for estrogen-related diseases such as breast cancer and endometriosis. Here, we tested the hypothesis that higher cadmium exposure is associated with endometriosis among infertile Japanese women in a hospital-based case-control study. We recruited consecutive female patients aged 20-45 years who had complained of infertility and presented to a university hospital in Tokyo. The subjects were interviewed and provided a urine sample prior to a laparoscopic diagnosis of endometriosis between January 2000 and December 2001. The severity of endometriosis was then dichotomized into controls (stage 0 and I) and cases (stage II-IV). We finally measured urinary total cadmium concentration in 54 cases and 74 controls as a biomarker of long-term cumulative exposure. Odds ratios were adjusted for average menstrual cycle length, body-mass index and smoking status using unconditional logistic regression. Results showed no association between endometriosis and urinary cadmium concentration. Medians (interquartile ranges) of urinary cadmium concentration in cases and controls were 0.53 (0.40-0.73) and 0.54 (0.34-0.76) microg/g creatinine, respectively (P for difference=0.88). Adjusted odds ratio (95% confidence interval) for the highest versus lowest tertile of urinary creatinine-adjusted cadmium concentration was 0.86 (0.30 to 2.49, P for trend=0.79). Our results do not support the hypothesis that higher urinary cadmium concentration is associated with the risk of endometriosis.     

Apple polyphenols influence cholesterol metabolism in healthy subjects with relatively high body mass index

We performed a randomized double-blind, placebo-controlled study on moderately obese male and female subjects (71 subjects) with a body mass index ranging from 23 to 30 to evaluate the efficacy of 12-week intake of polyphenols extracted from apples and hop bract (600 mg/day). We confirmed that 12-week ingestion of polyphenol-containing capsules significantly decreased total cholesterol and LDL-cholesterol levels. The effects of the apple polyphenol-containing capsules were more marked than those of the hop bract polyphenol-containing capsules. The visceral fat area and the level of adiponectin in the group administered apple polyphenols improved in comparison with the control group. Blood and physical examinations revealed on clinical problems, and no adverse reactions were observed during the ingestion period. These results demonstrate that apple polyphenols regulate fat metabolism in healthy subjects with relatively high body mass index.