Transport of subarctic large copepods from the Oyashio area to the mixed water region by the coastal Oyashio intrusion

The lateral transport of organic carbon in large grazing copepods ( Neocalanus cristatus, Neocalanus flemingeri, Neocalanus plumchrus and Eucalanus bungii ) from the Oyashio area to the mixed water region (MWR) by the coastal Oyashio intrusion was estimated using the data of VMPS (vertical multiple plankton sampler) and 1500 dbar-referred geostrophic transport from the CTD (conductivity temperature depth sensor) data of five cruises during June 2001 to April 2002 on a repeat observation section OICE (Oyashio Intensive observation line off Cape Erimo), which extends southeastward from Hokkaido Island, Japan. The transport to MWR by the coastal Oyashio intrusion was estimated to be 5.3 × 10¹¹ g C for the four species. Data from profiling floats also indicated that the copepods were advected from OICE to MWR by the coastal Oyashio intrusion within about 2 months. This transport is considered to be one of the significant sources of organic carbon in MWR as it is larger than the amount of large zooplankton consumed by Pacific saury ( Cololabis saira ) in MWR, one of the dominant copepod predators in this region.     

Follicular dynamics during the pre-ovulatory and subsequent first follicular wave stages affect the pregnancy outcome in Japanese Black cows

The diameters of the pre-ovulatory follicles (PF) and the largest follicle during the subsequent first follicular wave (W1LF), and plasma estradiol-17β (E₂) concentrations were monitored on Days 0, 1, 3, 5, and 7 (ovulation = Day 1). Pregnancy was diagnosed on Day 30. Cows were classified into two groups according to the location of the dominant follicle ipsilateral (IG) or contralateral (CG) to the corpus luteum on Day 7. From Days 3 to 7, some follicles that had been determined as the subordinate in the previous examination exceeded the W1LF located in the opposite ovary in terms of the diameter. These were defined as switching (SW), whereas others were defined as non-switching (NSW). The diameter of PF was significantly smaller in pregnant (P) animals than in non-pregnant (NP) animals. The plasma E₂ concentration on Day 0 was significantly higher in P animals than in NP animals and tended to be higher in NSW than in SW. In addition, plasma E₂ concentrations around Days 3 to 7 tended to be higher in P animals of NSW than in NP animals of SW. The conception rates did not differ between IG and CG but were significantly higher in NSW than in SW. In the IG group, the conception rate tended to be higher in NSW than in SW.     

Advanced maternal age induces fetal growth restriction through decreased placental inflammatory cytokine expression and immune cell accumulation in mice

Advanced maternal age is a risk factor for female infertility, and placental dysfunction is considered one of the causes of pregnancy complications. We investigated the effects of advanced maternal aging on pregnancy outcomes and placental senescence. Female pregnant mice were separated into three groups: young (3 months old), middle (8–9 months old), and aged (11–13 months old). Although the body weights of young and middle dams gradually increased during pregnancy, the body weight of aged dams only increased slightly. The placental weight and resorption rate were significantly higher, and live fetal weights were reduced in a maternal age-dependent manner. Although mRNA expression of senescence regulatory factors (p16 and p21) increased in the spleen of aged dams, mRNA expression of p16 did not change and that of p21 was reduced in the placenta of aged dams. Using a cytokine array of proteins extracted from placental tissues, the expression of various types of senescence-associated secretory phenotype (SASP) factors was decreased in aged dams compared with young and middle dams. The aged maternal placenta showed reduced immune cell accumulation compared with the young placenta. Our present results suggest that models using pregnant mice older than 8 months are more suitable for verifying older human pregnancies. These findings suggest that general cellular senescence programs may not be included in the placenta and that placental functions, including SASP production and immune cell accumulation, gradually decrease in a maternal age-dependent manner, resulting in a higher rate of pregnancy complications.     

Aluminum toxicity of synthetic aluminum–humus complexes derived from non-allophanic and allophanic Andosols and its amelioration with allophanic materials

Natural non-allophanic Andosols often show aluminum (Al) toxicity to Al-sensitive plant roots. The significance of Al–humus complexes to Al toxicity has been emphasized. Allophanic Andosols also possess Al–humus complexes, but they rarely show any toxicity. In the present study, using model substances, we tested the toxicity of Al–humus complexes and its amelioration with allophanic materials. We extracted humic substances from the A horizons of a non-allophanic Andosol and an allophanic Andosol using a NaOH solution, and reacted the humic substances and partially neutralized AlCl₃ solution at pH 4. Allophanic material was purified from commercial Kanuma pumice. Plant growth tests were conducted using a medium containing the Al–humus complexes (50 g kg⁻¹), the allophanic material (0, 90, 180 and 360 g kg⁻¹) and perlite. The root growth of barley ( Hordeum vulgare L.) and burdock ( Arctium lappa ) was reduced in the media containing the Al–humus complexes derived from both the non-allophanic and allophanic Andosols when the allophanic material was not added. With the addition of the allophanic materials, particularly in the 360 g kg⁻¹ treatment, the growth of the barley roots was improved markedly. Although the root growth of the burdock tended to improve with allophanic materials, the effect was weaker than that for barley. Monomeric Al in a solution of the medium was not detected (< 0.05 mg L⁻¹) following the addition of 360 g kg⁻¹ of allophanic materials, whereas 0.8–1.7 mg L⁻¹ Al was recorded without the allophanic material.     

Potential of near infrared spectroscopy to determine the lipid content of untreated garbage compost

The purpose of the present study was to evaluate the capability of near infrared spectroscopy (NIRS) as a simple method to monitor the lipid content of garbage compost, which is a potential inhibitor of plant growth. We conducted a cultivation experiment with vegetable mock pak choy ( Brassica rapa L. Parachinensis Group) using two application rates of four garbage composts that differed in lipid content. The input of lipid from the compost to the field showed a significant negative correlation with germination rate and plant height in the initial growth stage. Reflectance spectra of untreated and freeze-dried and milled compost samples were taken using a scanning monochromator. Second-derivative spectra and multiple regression analysis were used to develop calibration equations for lipid and moisture contents. The calibration was carried out with the short wavelength region ([SWR] 800–1100 nm) and the long wavelength region ([LWR] 1100–2500 nm) separately. The calibration equations with the LWR were more accurate than those with the SWR for lipid and moisture determinations. The accuracies of the calibration equations for untreated samples were comparable to those for freeze-dried and milled samples. In conclusion, we suggest that the application rate of garbage compost can be determined by measuring the lipid content of untreated samples by NIRS.     

CHARACTERIZATION OF CANINE FOCAL LIVER LESIONS WITH CONTRAST-ENHANCED ULTRASOUND USING A NOVEL CONTRAST AGENT—SONAZOID

Contrast-enhanced ultrasound using Sonazoid, a novel contrast medium with a liver-specific Kupffer phase, was evaluated in canine focal liver lesions Twenty-five dogs with a liver mass were given intravenous Sonazoid, and the enhancement pattern in the arterial, portal, and parenchymal phase was characterized. An enhancement defect in the lesion in the parenchymal phase was observed in all malignant lesions, whereas only one of nine benign lesions had a filling defect. The diagnostic value of the presence of a filling defect for malignancy was statistically significant (100% sensitivity, 88.9% specificity, 94.1% positive predictive value, 100% negative predictive value), and was equal to that of hypoenhancement in the portal or delayed phase. The defect pattern (clear or irregular defect) was dependent ( P <0.05) on the types of malignancy (i.e., hepatocellular carcinoma and other types of malignancies). In the arterial phase, five of the six hepatocellular carcinomas had hypervascularity, whereas no other lesion was characterized by hypervascularity. In some dogs, additional lesions that could not be observed with conventional B-mode ultrasonography were detected in the parenchymal phase. The enhancement pattern of Sonazoid, especially in the parenchymal phase, has potential as a diagnostic tool for canine focal liver lesions.     

Molecular changes associated with adaptation of equine influenza H3N8 virus in embryonated chicken eggs

Embryonated chicken eggs (ECEs) are routinely used to isolate equine influenza virus. Propagation of the virus in ECEs results in selection of variants. In the present study, we determined nucleotide sequences of entire coding regions of parent A/equine/Tottori/1/07 (H3N8) and its derivatives that have different passage histories in ECE. After 12 passages, nucleotide sequence analysis predicted 3 amino acid substitutions in hemagglutinin (HA; 2 in HA1 and 1 in HA2). The two amino acid substitutions in HA1 were located in the vicinity of the cell receptor-binding site. Three other amino acid substitutions were predicted in internal proteins, 1 in the M1, 1 in the NP and 1 in the PA. This is the first report showing mutations in the internal protein genes of equine influenza virus associated with adaptation to ECE.     

National-scale estimation of methane emission from paddy fields in Japan: Database construction and upscaling using a process-based biogeochemistry model

We have estimated methane (CH₄) emission from total rice (Oryza sativa L.) paddies in Japan by means of a process-based biogeochemistry model, DeNitrification-DeComposition(DNDC)-Rice, combined with a geographic information system (GIS) database of climate, soil and farming practices. In the GIS database, 2 million ha of rice paddies were divided into 17,408 units according to 136 climate areas, 16 soil types, four classes of drainage rate and two classes of groundwater level, to simulate CH₄ flux from each of the units applying the DNDC-Rice model. As a result, the national-scale CH₄ emission in 1990 was estimated to be 216 Gg carbon (C), 13% lower than a previous inventory estimated by the Tier 2 method. By our Tier 3 approach, a relatively higher CH₄ flux was estimated from eastern regions than from western regions of Japan, presumably due to the differences in climate and water management. Sensitivity analysis and uncertainty assessment indicated that it is important to account for the heterogeneity in soil properties such as field water capacity, iron (Fe) concentration and drainage rate, in order to reduce the uncertainty in regional estimates.