Nanofibrillated Bacterial Cellulose Modified with (3-Aminopropyl)trimethoxysilane under Aqueous Conditions: Applications to Poly(methyl methacrylate) Fiber-Reinforced Nanocomposites.

The development of eco-friendly fiber-reinforced composite resins is an important objective from an environmental perspective, and nanofibrillated bacterial cellulose (NFBC), with extremely long high-aspect-ratio fibers, is a filler material with high potential for use in such composite resins. In this study, we investigated chemical modification of the surfaces of NFBC fibers by coupling with (3-aminopropyl)trimethoxysilane and fabricated nanocomposite materials using the prepared surface-modified NFBC. The product prepared by the one-pot reaction of (3-aminopropyl)trimethoxysilane with NFBC microfibrils dispersed in aqueous acid retained the same nanofibril structure as the intact NFBC. The degree of molar substitution and the silicon states on the surface of the product depended on the NFBC/(3-aminopropyl)trimethoxysilane ratio. The thermal analysis revealed that the thermal degradation temperature of the products increases with an increase of degree of molar substitution. Highly transparent (78-89% at 600 nm) poly(methyl methacrylate)-based nanocomposites were prepared by solvent casting; the nanocomposite containing 1.0 wt % (3-aminopropyl)trimethoxysilylated NFBC was only 8% less transparent than neat poly(methyl methacrylate) at 600 nm. In addition, the tensile strength of the nanocomposite was more than twice that of neat poly(methyl methacrylate) when 1 wt % of the surface-modified NFBC was added. The surface-modified NFBC is expected to be a reinforcing nanofiber material that imparts excellent physical properties to fiber-reinforced resins.

Concentrations of 137Cs radiocaesium in the organs and tissues of low-dose-exposed wild Japanese monkeys.

OBJECTIVES: Following the massive earthquake that struck eastern Japan on March 11, 2011, a large amount of radioactive material was released into the environment from the damaged reactor of the Fukushima Daiichi Nuclear Power Plant (FDNPP). After the FDNPP accident, radiocaesium was first detected in muscle samples from wild Japanese monkeys exposed to radioactive materials, and haematologic effects, changes in head size, and delayed body weight gain were also reported, but little is known about the distribution of 137Cs in the organs and tissues of wild Japanese monkeys. RESULTS: We detected the 137Cs in various organ and tissue samples of 10 wild Japanese monkeys inhabiting the forested areas of Fukushima City that were captured between July and August 2012. Among muscle, brain, heart, kidney, liver, lung, and spleen, muscle exhibited the highest and the brain the lowest 137Cs concentration. The concentration (mean ± SD) of 137Cs in muscle, brain, heart, kidney, liver, lung, and spleen was 77 ± 66, 26 ± 22, 41 ± 35, 49 ± 41, 41 ± 38, 53 ± 41, and 53 ± 51 Bq/kg, respectively. These results can help us understand the biological effects of long-term internal radiation exposure in non-human primates.

The Number of Louse Eggs on Wild Japanese Macaques (Macaca fuscata) Varies with Age, but Not with Sex or Season.

During grooming, primates remove harmful ectoparasites, such as ticks and lice, and there is direct evidence for a health benefit of tick removal. Grooming behaviors differ among primates with respect to age and sex. Moreover, the number of ectoparasite may exhibit seasonal variation. Therefore the number of ectoparasites on a host may vary with effects, host age and sex, and season. However, these effects have not been a focus of louse infestation studies of primates. Grooming in Japanese macaques is related to sex and age, with developmental changes in behavior corresponding to the timing of tooth eruption. Moreover, behavioral data for Japanese macaques suggest that lice load may differ with the season. Thus, we examined whether the number of louse eggs varies according to host macaque sex, age, and season, and whether it changes in response to tooth eruption. We counted unhatched and hatched eggs attached to the hair on six 1-cm2 areas on the left wrist skin of culled macaques, using a stereoscopic microscope. We sampled five winter coats and three summer coats for each age class: infant, juvenile, adolescent, and adult. The number of unhatched and hatched eggs was related to age, but not to sex and season. There were significant differences in the number of unhatched eggs between infants and adults, juveniles and adults, and adolescents and adults. There were also significant differences in the number of hatched eggs between infants and adults, juveniles and adults, adolescents and adults. Tooth eruption did not influence the number of louse eggs. These results suggest that researchers should consider the age of host animals when assessing the relationship between grooming and ectoparasites.

Methods of evaluating the spermatogenic ability of male raccoons (Procyon lotor).

Feral raccoons (Procyon lotor) have been growing in number in Japan, and they are becoming a problematic invasive species. Consequently, they are commonly captured and killed in pest control programs. For effective population control of feral raccoons, it is necessary to understand their reproductive physiology and ecology. Although the reproductive traits of female raccoons are well known, those of the males are not well understood because specialized knowledge and facilities are required to study them. In this study, we first used a simple evaluation method to assess spermatogenesis and presence of spermatozoa in the tail of the epididymis of feral male raccoons by histologically examining the testis and epididymis. We then evaluated the possibility of using 7 variables-body weight, body length, body mass index, testicular weight, epididymal weight, testicular size and gonadosomatic index (GSI)-to estimate spermatogenesis and presence of spermatozoa in the tail of the epididymis. GSI and body weight were chosen as criteria for spermatogenesis, and GSI was chosen as the criterion for presence of spermatozoa in the tail of the epididymis. Because GSI is calculated from body weight and testicular weight, this model should be able to be used to estimate the reproductive state of male raccoons regardless of season and age when just these two parameters are known. In this study, GSI was demonstrated to be an index of reproductive state in male raccoons. To our knowledge, this is the first report of such a use for GSI in a member of the Carnivora.

Low blood cell counts in wild Japanese monkeys after the Fukushima Daiichi nuclear disaster.

In April 2012 we carried out a 1-year hematological study on a population of wild Japanese monkeys inhabiting the forest area of Fukushima City. This area is located 70 km from the Fukushima Daiichi Nuclear Power Plant (NPP), which released a large amount of radioactive material into the environment following the Great East Japan Earthquake of 2011. For comparison, we examined monkeys inhabiting the Shimokita Peninsula in Aomori Prefecture, located approximately 400 km from the NPP. Total muscle cesium concentration in Fukushima monkeys was in the range of 78-1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.

Concentration of radiocesium in the wild Japanese monkey (Macaca fuscata) over the first 15 months after the Fukushima Daiichi nuclear disaster.

Following the massive earthquake that struck eastern Japan on March 11, 2011, a nuclear reactor core meltdown occurred at the Fukushima Daiichi Nuclear Power Plant, operated by Tokyo Electric Power Company, and was followed by the release of large amounts of radioactive materials. The objective of this study was to measure the concentration of radiocesium (134)Cs and (137)Cs in the muscle of Japanese monkeys (Macaca fuscata) inhabiting the forest area of Fukushima City and to determine the change in concentration over time as well as the relationship with the level of soil contamination. Cesium concentrations in the muscle of monkeys captured at locations with 100,000-300,000 Bq/m(2) were 6,000-25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000-3,000 Bq/kg in some animals during and after December 2011 before returning to 1,000 Bq/kg in April 2012, after which it remained relatively constant. This pattern of change in muscle radiocesium concentration was similar to that of the change in radiocesium concentration in atmospheric fallout. Moreover, the monkeys feed on winter buds and the cambium layer of tree bark potentially containing higher concentrations of radiocesium than that in the diet during the rest of the year. The muscle radiocesium concentration in the monkeys related significantly with the level of soil contamination at the capture locations.

Indices using external measurements for assessing fat deposition of adult feral raccoons (Procyon lotor) in Kanagawa Prefecture, Japan.

We examined the use of external measurements and relative fat deposition of adult feral raccoons (Procyon lotor) to develop relative indices of body fat deposition in post-growth feral raccoons. From March 2006 to March 2010, 288 adult raccoon carcasses (110 males, 178 females) collected in Kanagawa Prefecture, Japan, which were determined to be 24 months old, were subjected to external measurements of body weight (BW), girth measurement (GM), and body mass index (BMI). To assess relative body fat deposition, we visually classified abdominal subcutaneous fat into three grades (Visible Fat Index [VFI]: I-III). Significant differences in the means of BW (both sexes:P<0.01), GM (females: P<0.05, males: P<0.01), and BMI (both sexes: P<0.01) were detected between seasons. Notably, the means of BW, GM, and BMI (all, both sexes: P<0.01) differed significantly between VFI grades. However, by discriminant analysis with BW, GM, and BMI as independent variables, we obtained a significant discriminant function (both sexes: P<0.01) for distinguishing VFI I from higher VFI grades, but no significant equation was obtained for distinguishing between VFI II and VFI III. Based on the obtained structure matrix of discriminant analysis, BMI was the most valuable component for the discrimination of VFI grades. Thus, we conclude that BMI is a suitable complementary index for assessing relative body fat deposition of adult feral raccoons in Kanagawa Prefecture and may be generalizable to populations in other areas.

Difference in age at first conception between early and late litters of feral raccoon (Procyon lotor) in Kanagawa prefecture.

Due to the long parturition period of raccoons, we assumed that age at first conception of late born females was later than that of early born females. From March 2005 to September 2008, 201 females estimated to be younger than 24 months were separated into early- and late-born groups on the basis of their estimated birth month (to the nearest 2 months), and parous status and body mass index (BMI) were examined. Age at first conception of late-born females (over 18 months old) was estimated to be later than that of early-born females (over 12 months old). The average BMI in early-born individuals at 12 months old might have affected their ability to conceive because of body fat deposition.