Nitrogen use by <Emphasis Type="Italic">Pinus densiflora</Emphasis> trees growing on a Mt. Fuji lava flow

To quantify the nitrogen (N) use by Pinus densiflora trees growing on an infertile lava surface, N pools, N requirement and N uptake through fine roots and N deposition from the atmosphere were estimated. The N requirement and the N uptake of fine roots were 55.5kgNha^–1year^–1 and 39.7kgNha^–1, respectively. Thus, the ratio of N uptake to N requirement of the fine roots was 71.5%. Including fine-root contribution, the total N requirement of the P. densiflora trees was 98.6kgNha^–1year^–1, and the total N uptake was 64.2kgNha^–1year^–1. Thus, the N uptake of the P. densiflora trees was 64.1% of the N requirement, indicating that P. densiflora trees growing on an infertile lava surface obtain some of their N from below-ground organic material layers every year and the contribution of N storage in trees for their growth is not any higher than indicated in previous reports that excluded fine-roots contribution. The wet N deposition of our research forest was only 5.8% of the N requirement of the P. densiflora trees and only 8.9% of the N uptake. Movement of the below-ground organic material layer N concentrations in the F- and L-layers coincides with needle development and fine-root growth, suggesting the possibility that P. densiflora trees extract N from the organic N of those layers for growth.     

Effects of oral administration of furosemide and torsemide in healthy dogs

OBJECTIVE: To investigate the diuretic effects, tolerability, and adverse effects of furosemide and torsemide after short- and long-term administration in healthy dogs. ANIMALS: 8 mixed-breed dogs. PROCEDURES: In a crossover study, furosemide (2 mg/kg), torsemide (0.2 mg/kg), or placebo (bifidobacterium [1 mg/kg]) was administered orally to each dog every 12 hours for 14 days. Blood and urine samples were collected before the study (baseline data) and at intervals on the 1st (short-term administration) and 14th day (long-term administration) of treatment for assessment of urine volume and specific gravity and selected clinicopathologic variables including BUN, creatinine, and aldosterone concentrations, and creatinine clearance. RESULTS: Compared with the baseline value, short-term administration of furosemide or torsemide immediately increased urine volume significantly; after long-term administration of either drug, urine specific gravity decreased significantly. Compared with the effect of placebo, the 24-hour urine volume was significantly increased after short-term administra-tion of furosemide or torsemide. In addition, it was significantly increased after long-term administration of torsemide, compared with that of short-term administration. Long-term administration of furosemide or torsemide increased the BUN and plasma creatinine con-centrations, compared with the baseline value. Compared with the baseline value, plasma aldosterone concentration was significantly increased after long-term administration of either drug and was significantly higher after torsemide treatment than after furosemide treatment. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, diuretic resistance developed after 14 days of furosemide, but not torsemide, administration; however, both loop diuretics were associated with increased BUN and plasma creatinine concentrations, compared with values before treatment.     

Evaluation of gas diffusivity models for no-tilled and tilled volcanic ash soils

Accurate quantification of soil gas diffusion is essential to understand the gas transport mechanism in soils, especially for soil greenhouse gas emissions. To date, the performance of soil gas diffusivity (D_p/D₀, where D_p is the soil gas diffusion coefficient and D₀ is the diffusion coefficient in free air) models has seldom been evaluated for no-tilled and tilled volcanic ash soils. In the present study, six commonly used models were evaluated for volcanic ash soils under two treatments by comparing the predicted and measured soil gas diffusivities at water potentials of pF 1.3–3. The Buckingham-Burdine-Campbell (BBC), soil-water-characteristic-dependent (SWC-dependent), and two-region extended Archie’s Law (2EAL) models showed better performance for both no-tilled and tilled volcanic ash soils, which is likely because porosity and pore size parameters of bimodal soils were taken into consideration in these models. Since the BBC model showed better accuracy than the SWC-dependent and 2EAL models and required fewer, more easily measurable parameters, this study recommends the BBC model for predicting soil gas diffusivity of volcanic ash soil under different tillage managements. In future studies, the BBC model should be further tested at water potentials of pF > 3, and may be improved by including the parameters of pore continuity and saturation.     

Dynamic left ventricular outflow tract obstruction secondary to hypovolemia in a German Shepard dog with splenic hemangiosarcoma

Dynamic left ventricular outflow tract obstruction (DLVOTO) is a common condition in cats and humans. In this case report, a dog is described with DLVOTO secondary to severe intra-abdominal hemorrhage caused by a hemangiosarcoma. The dog was a 9-year-old, 35.7-kg, spayed female German Shepard dog that presented with a history of tachypnea and collapse. A Levine II/VI systolic murmur was present at the heart base. Abdominal ultrasonography revealed a splenic mass and a large amount of ascites. Echocardiography showed a reduced left ventricular diameter and an increased aortic velocity caused by systolic anterior motion (SAM) of the mitral valve apparatus. The heart murmur and the SAM were resolved after treatment including a splenectomy and a blood transfusion.     

Successful blastocyst production by intracytoplasmic injection of sperm after in vitro maturation of follicular oocytes obtained from immature female squirrel monkeys (Saimiri boliviensis)

Advanced reproductive technologies are being applied for the propagation of squirrel monkeys, to ensure their preservation as a genetic resource and the effective use of their gametes in the future. In the present study, oocytes and spermatozoa were collected from live squirrel monkeys, following which piezo intracytoplasmic sperm injection (ICSI) was performed using these gametes. Follicular development was induced by administering equine chorionic gonadotropin (eCG) containing inhibin antiserum to an immature squirrel monkey female. The unilateral ovary was excised after the administration of human chorionic gonadotropin (hCG), to induce ovulation, following which the larger developed follicular oocytes were collected. Follicular oocytes were prepared for ICSI using sperm from the epididymal tail of a unilateral testis extracted from a mature male. The embryos were continuously incubated in CMRL 1066 medium supplemented with 10% (v/v) fetal bovine serum. Embryo culture was performed with cumulus cells. Two experiments of ICSI carried out with three females resulted in 14 mature oocytes from the 49 cumulus-oocyte complexes collected and five embryos, three of which developed into blastocysts. These blastocysts were vitrified, thawed, and transferred to recipient monkeys, but no pregnancies resulted. In conclusion, the present study is the first to successfully produce ICSI-derived blastocysts from MII oocytes obtained by means of hormone administration (a combination of eCG+inhibin antiserum and hCG) and in vitro maturation in immature squirrel monkeys.     

Practical Application of Miyazaki Jitokko Chickens Selected for a Superior Allele at a Single Nucleotide Polymorphism Site in the Cholecystokinin Type A Receptor Gene

This study aimed to examine 1) whether selection for a superior allele at a single nucleotide polymorphism site (SNP; {"type":"entrez-nucleotide","attrs":{"text":"AB604331","term_id":"315258605","term_text":"AB604331"}}AB604331, g.420 C>A) of the chicken cholecystokinin type A receptor (CCKAR) gene in Miyazaki Jitokko chickens is detectable in commercial poultry farms, and 2) whether the reproductive traits of the Kyushu Rhode hens, as a maternal stock line of the Miyazaki Jitokko chickens, are affected by SNP selection. Conventional and A-allele fixed (improved) Miyazaki Jitokko chicks were hatched on the same day and raised in a battery cage until 7 days of age. The chicks were then deposited at two commercial poultry farms and reared until slaughter at 126 and 163 days for cockerels and pullets, respectively. Body weight on the day of hatching (day 0), at 5 days of age, and at slaughter were measured. The differences in the body weights of the farm and test groups at slaughter were analyzed using the generalized linear model. A-allele fixation increased the body weight at slaughter by approximately +123.5 g and +131.9 g in cockerels and pullets, respectively. No significant differences between the conventional and improved hens were detected in terms of egg-laying rate, fertilization rate, and hatchability in the Kyushu Rhode hens. The data suggest that fattening chicks can be supplied as usual, even if Kyushu Rhode hens are switched from the conventional to improved type. In conclusion, genetic improvements using the CCKAR SNP site as a marker were effectively established in terms of the growth of the Miyazaki Jitokko chickens in commercial farms and the reproductive traits of the Kyushu Rhode hens.     

Factors affecting the dynamics of the population of Fagus crenata in the Takakuma Mountains, the southern limit of its distribution area

The refugee population of Fagus crenata in the Takakuma Mountains, Kyushu, Japan, represents the southern limit of this species' distribution area. Because this population is the most exposed to the global warming effect, records of this population are likely to provide useful information on the response of this species to global warming. The aim of this study was to record the present status of this valuable population, enabling judgment of its sustainability. The density of successive F. crenata trees and saplings was low regardless of the coverage of dwarf bamboo. Moreover, the proportion of empty nuts observed was considerably high, suggesting to be the likely major factor limiting recruitment of saplings or successors in this population. Radial growth of F. crenata was shown to have been decreasing for the past 50 years, and there was a significantly negative correlation with the warmth index. The decreasing growth rate and poor regenerative ability caused by the high proportion of empty nuts suggest the possibility that this population will degrade further in the future, possibly being replaced by shrubs and small tree species.