Effects of crown release on basal area growth rates of some broad-leaved tree species with different shade-tolerance

We compare three or four years effects of crown release on stem growth rates among four deciduous broad-leaved tree species,Fagus crenata, Quercus crispula, Magnolia obovata andAcer mono, in an even-aged coppice forest, central Japan. The crown release significantly improved relative growth rates for basal-area (RGR_BA) of the four species. However the effects of neighboring gap area (GAPA) on the RGR_BA differed among the species. The effects were significant forQ. crispula andM. obovata, indicating that growth rates of these two species increase with intensity of the crown release. In contrast, the RGR_BA ofF. crenata andA. mono were not correlated with the GAPA, suggesting that their growth rates are unrelated to the intensity. We considered that such differences among species were closely related to their photosynthetic characteristics of light use; less-tolerant species (Q. crispula andM. obovata) exhibit greater growth rates relative to the intensity of crown release than tolerant species (F. crenata andA. mono). Based on these results, we proposed implications for thinning practices in mixed forests of species with different shade-tolerance.     

Estimating larval supply of Ezo abalone <Emphasis Type="Italic">Haliotis discus hannai</Emphasis> in a small bay using a coupled particle-tracking and hydrodynamic model: insights into the establishment of harvest refugia

Most juveniles of Haliotis discus hannai have been found to be descendants of wild individuals, although most adults were artificially produced (released) individuals as a result of restocking inside the refugium located near the head of Oshoro Bay, Hokkaido, Japan. To estimate the larval supply from released and wild individuals into the refugium and to compare the suitability of locations as larval sources, we simulated larval dispersal using a coupled hydrodynamic and particle-tracking model. The simulation results indicated that more larvae may be supplied from the wild adults inside the bay to the refugium than from the released adults. These results are consistent with the observed high abundance of wild juveniles in the refugium. Most larvae from the refugium were predicted to disperse out of the bay. We found that larval retention in the bay was at least one order of magnitude higher than that in the refugium. Thus, it may be more effective in terms of self-replenishment and reproduction if the refugium were to be expanded to the bay scale. There were only minor differences among the compared sites at the head of the bay in terms of their suitability as larval sources. Consequently, the establishment of new refugia in this area could be expected to provide an effectiveness equal to that of the current refugium.     

Changes in renin‐angiotensin‐aldosterone system during cardiac remodeling after mitral valvuloplasty in dogs

BackgroundInformation regarding changes in renin‐angiotensin‐aldosterone system (RAAS) during cardiac remodeling after mitral valvuloplasty (MVP) in dogs remains lacking.Hypothesis/ObjectivesTo assess the longitudinal effects of MVP on circulating RAAS activity.AnimalsEight client‐owned dogs receiving MVP for myxomatous mitral valve disease (MMVD).MethodsThis is a cohort study. Plasma renin activity (PRA), angiotensin II (AT2), aldosterone (PAC), blood urea nitrogen (BUN), and creatinine concentrations, were measured in these dogs before (baseline) and at 3 consecutive monthly follow‐ups (Post‐1M, Post‐2M, Post‐3M). Echocardiography was concomitantly used to assess the process of cardiac recovery after MVP.ResultsThe echocardiography revealed a significant decrease in LVIDDN, LA/Ao, FS, E velocity, E/A, E′ sep, S′ lat, E′ lat, and A′ lat after MVP compared with baseline (P < .05). There was a significant reduction in the PRA (2.45, 3.05, 2.74 vs 8.8 ng/mL/h; P = .002), AT2 (466, 315, 235 vs 1200 pg/mL; P = .009), and PAC (39.88, 47, 54.62 vs 179.5 pg/mL; P = .01), respectively at Post‐1M, Post‐2M, Post‐3M compared to the baseline. Additionally, BUN and creatinine concentrations decreased from Post‐1M. The RAAS variables showed significant, weak to moderate, relationship with selected echocardiographic variables.Conclusions and Clinical ImportanceMitral valvuloplasty contributes to decreased RAAS activity in MMVD dogs, which paralleled the process of cardiac reverse remodeling up to Post‐3M. This information facilitates formulating strategies to optimize clinical outcomes for dogs after MVP.     

Introduction: the coastal ecosystem complex as a unit of structure and function of biological productivity in coastal areas

Coastal seas are composed of relatively independent ecosystems, such as estuaries, rocky shores, mangroves, and coral reefs. Such individual ecosystems (IEs) are linked closely to each other by the dispersal and circulation of nutrients and organic matter and the movement of organisms, and form a coastal ecosystem complex (CEC). The CEC is understood as a unit of structure and function of coastal seas. It is characterized by a high degree of species diversity and it plays a large role in fishery and aquaculture production, as it provides important marine services for humans. This special volume compiles recent ecological studies of target species and IEs, to facilitate the conservation of coastal seas and the sustainability and production of their fisheries and aquaculture based on our understanding of the structure and function of the CEC in these environments.     

Gonadal development in early life stages of <Emphasis Type="Italic">Spratelloides gracilis</Emphasis>

ABSTRACT:   The gonad of Spratelloides gracilis was not sexually differentiated in the yolk-sac, preflexion, flexion and postflexion stages. Sexual differentiation and development of the ovary and testis started in the transition stage from larva to juvenile. In juveniles at the fin ray completion stage, the ovary and testis could be distinguished because the ovary contained germ cells initiating meiosis and the testis had blood vessels and a high density of somatic cells. The ovary further developed in larger juveniles to have oocytes of perinucleolus stage together with those of the chromatin nucleolus stage, and oogonium. However, in the testis of larger juveniles, primary spermatogonium began proliferation by meiosis. Sexual differentiation may be regarded as one of morphological and functional changes accompanying metamorphosis in S. gracilis . Some fish larger than the mature size of 60 mm standard length had advanced germ cells and functional gonads, others did not have functional gonads. The distal end of the immature gonads did not connect with a genital duct near the anus. These observations indicate that S. gracilis has large variability in size-at-maturity. The variability in size-at-maturity in S. gracilis , together with large variability in age-at-maturity, may constitute an ecological basis for an extended spawning season in S. gracilis .     

Shelter effects of coralline algal turfs: protection for Turbo cornutus juveniles from predation by a predatory gastropod and wrasse

Laboratory experiments were conducted to examine the shelter effects of turfs of articulated coralline algae (ACA) for the Japanese spiny turban snail Turbo cornutus. The muricid gastropod Ergalatax contractus and the cockerel wrasse Pteragogus flagellifer were used as predators. When the muricid snail was used as a predator, the existence of ACA fronds improved the survival rate of the turban snail juveniles compared with the experimental treatment without ACA fronds. Refuge provided by ACA fronds against predation by the muricid snail was more notable for smaller-sized turban snail juveniles (5.8 mm in shell height) than those of a larger size (8.6 mm in shell height). In the experiment using the wrasse as a predator, a shelter effect was demonstrated for turban snail juveniles of two size groups (4.3 and 10.2 mm in shell height). ACA turfs hindered foraging by the wrasse, so the survival rate of the juveniles was greatly increased. No clear difference was observed between the two size groups of the turban snail in terms of the shelter effect of ACA turf. The shelter effect of ACA turfs for turban snail juveniles is thought to derive from the physical characteristics of the algae, which form a visual and physical barrier.     

Correlation analysis of hypothalamic mRNA levels of appetite regulatory neuropeptides and several metabolic parameters in 28‐day‐old layer chickens

Various lines of evidence suggest that appetite‐related neuropeptides in the hypothalamus are regulated by adiposity signals such as leptin and insulin in mammals. In the present study, we examined age‐dependent changes in the weight of abdominal fat and hypothalamic mRNA levels of neuropeptide Y (NPY, an orexigenic neuropeptide) and proopiomelanocortin (POMC, a precursor of anorexigenic neuropeptides) in growing chickens at 7, 14, 21 and 28 days of age. Hypothalamic NPY mRNA levels were significantly (P < 0.05) decreased after 14 days of age, whereas hypothalamic POMC mRNA levels were significantly (P < 0.05) increased at 28 days of age. The percentage of abdominal fat was significantly increased after 14 days of age in chickens. We next examined the correlation of hypothalamic NPY and POMC mRNA levels and several parameters at 28 days of age. There were no significant correlations between hypothalamic mRNA levels of NPY or POMC and the percentage of abdominal fat. These findings suggest that the gene expressions of NPY and POMC do not depend on adiposity in chickens, at least in 28‐day‐old layer chickens.     

Nuclear and mitochondrial DNA polymorphisms suggest introgression contributed to garden beet (Beta vulgaris L.) domestication

Genetic Resources and Crop Evolution - Garden beet is the ancestor of fodder beets and sugar beets, but the origin of garden beet’s genetic potential to evolve novel beet types is debatable....     

Mitochondrial genome diversity in <Emphasis Type="Italic">Beta vulgaris</Emphasis> L. ssp. <Emphasis Type="Italic">vulgaris</Emphasis> (Leaf and Garden Beet Groups) and its implications concerning the dissemination of the crop

Four mitochondrial minisatellites were used to study cytoplasmic diversity in leaf and garden beet germplasm resources. Eleven multi-locus haplotypes were identified, of which one (named mitochondrial minisatellite haplotype 4, hereafter min04) was associated with male-sterile Owen cytoplasm and two others (min09 and min18), with a normal fertile cytoplasm. European leaf beet germplasm exhibited the greatest haplotype diversity, with min09 and min18 predominating. In North African leaf beet accessions, only these two haplotypes were observed, making it likely that North African accessions were descended from European genotypes. The prevalence of min18 was also noted in leaf beet from the Middle East and western Asia. Such a pattern contrasts with that found in east Asian leaf beet where the two haplotypes were extremely rare. The geographical structure of the mitochondrial haplotypes allowed us to infer possible dissemination pathways of leaf beet. Additionally, we showed that mitochondrial genome diversity was low in garden beet germplasm, with min18 being highly predominant. An explanation of this limited diversity may lie in the geographically restricted origin of as well as relatively short cultivation histories of garden beet.