Phosphorus release from forest harvesting on an upland blanket peat catchment     

Michael Rodgers  Mark O’Connor  Mark Gerard Healy  Connie O’Driscoll  Zaki-ul-Zaman Asam  Mika Nieminen  Russell Poole  Markus Müller  Liwen Xiao 《Forest Ecology and Management》2010

The aim of this study was to investigate the release of phosphorus (P) to receiving waters resulting from harvesting 34-year-old lodgepole pine trees in an upland peat catchment. The study site was within a 25.3-hectare (ha) area, and was drained by a stream that received flows from ploughed furrows, mainly, via collector drains, and discharged directly to the salmonid Shrahrevagh River, Burrishoole, Co. Mayo, Ireland. The study site was divided into two parts: the upstream part was left intact and the downstream part was harvested in early Autumn 2005 following implementation of forest guidelines. Good management practices such as proper use of brash mats and harvesting only in dry weather were implemented. Two instrumented stations were established – one just upstream (US) and the other just downstream (DS) of the clearfelled area. The measurement of P concentrations at the two stations commenced in May 2005, two months before the harvesting started. The daily mean P concentration at the DS station increased from about 6 μg L⁻¹ of total reactive phosphorus (TRP) during pre-clearfelling to 429 μg L⁻¹ in August 2006. By October 2009, four years after clearfelling, the P concentrations at the DS station had returned to pre-clearfelling levels. In the first three years after harvesting, up to 5.15 kg ha⁻¹ of TRP was released from the harvested catchment to the receiving water; in the second year alone, 2.3 kg ha⁻¹ of TRP was released. Linear regression can be used to describe the relationship between TRP load and water discharge. About 80% of the total phosphorus (TP) in the study stream was soluble and more than 70% of the P release occurred in storm events, indicating that traditional buffer strips with widths of 15–20 m might not be efficient for P immobilization. The P concentrations were affected by antecedent weather conditions and highest concentrations occurred during storm events following prolonged drought periods. The water extractable phosphorus (WEP) contents in the soil were significantly higher below windrow/brash material than in brash-free areas, and whole-tree harvesting should be studied as one of the means to decrease P export from blanket peats.  相似文献   

Comparison of effects of ultraviolet and<Superscript>60</Superscript>Co gamma ray irradiation on nylon 6 mono-filaments     

Mika?OhtsukaEmail author  Yoshino?Suzuki  Tetsuya?Sakai  Anil?N.?Netravali 《Fibers and Polymers》2004,5(3):225-229

The effect of UV and⁶⁰Co gamma radiations on the physical and mechanical properties of nylon 6 mono-filaments with different draw ratios has been studied. Specimens were exposed to either up to 25 Mrad of gamma or up to 168 hrs of intense UV irradiation. The results show that nylon mono-filaments exposed to gamma rays, with much higher quantum energy than UV, undergo a larger extent of molecular chain scission. Higher irradiation dose also results in the production of insoluble, macroscopic three-dimensional cross-linked network structure. The amorphous regions with a lower density of cohesive energy (lower molecular orientation) show a higher extent of cross linking reaction whereas amorphous regions with a higher density of cohesive energy (higher orientation) show higher extent of chain scission reaction, irrespective of UV ray or gamma ray irradiation.  相似文献   

Central injection of ketone body suppresses luteinizing hormone release via the catecholaminergic pathway in female rats     

Iwata K  Kinoshita M  Susaki N  Uenoyama Y  Tsukamura H  Maeda K 《The Journal of reproduction and development》2011,57(3):379-384

Ketosis is found in various pathophysiological conditions, including diabetes and starvation, that are accompanied by suppression of gonadal activity. The aim of the present study was to determine the role of ketone body in the brain in regulating pulsatile luteinizing hormone (LH) secretion in female rats. Injection of 3-hydroxybutyrate (3HB), a ketone body, into the fourth cerebroventricle (4V) induced suppression of pulsatile LH secretion in a dose-dependent manner in ovariectomized (OVX) rats with an estradiol (E2) implant producing diestrus plasma E2 levels. Plasma glucose and corticosterone levels increased immediately after the 4V 3HB injection, suggesting that the treatment caused a hunger response. The 3HB-induced suppression of LH pulses might be mediated by noradrenergic inputs to the hypothalamic paraventricular nucleus (PVN) because a local injection of α-methyl- p-tyrosine, a catecholamine synthesis inhibitor, into the PVN blocked 3HB-induced suppression of LH pulses and PVN noradrenaline release was increased by 4V 3HB injection in E2-primed OVX rats. These results suggest that ketone body sensed by a central energy sensor in the hindbrain may suppress gonadotropin release via noradrenergic inputs to the PVN under ketosis.  相似文献   

Development and validation of a sandwich ELISA for use in measuring concentrations of canine surfactant protein A in serum of dogs     

Sone K  Akiyoshi H  Aoki M  Sugii S  Ohashi F 《American journal of veterinary research》2011,72(6):833-837

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High levels of sugars and fructan in mature seed of sweet wheat lacking GBSSI and SSIIa enzymes     

Shimbata T  Inokuma T  Sunohara A  Vrinten P  Saito M  Takiya T  Nakamura T 《Journal of agricultural and food chemistry》2011,59(9):4794-4800

Sweet wheat (SW), which lacks functional granule-bound starch synthase I (GBSSI) and starch synthase IIa (SSIIa), accumulates high levels of free sugars in immature seeds. Here, we examined the effects of the lack of these two enzymes on mature kernel composition. Whole grain flour of SW had higher levels of sugars, particularly maltose, slightly higher ash and protein content, approximately two to three times higher lipid levels, and about twice as much total dietary fiber as parental or wild-type lines. Considerably higher levels of low-molecular-weight soluble dietary fiber (LMW-SDF), largely consisting of fructan, were also detected in SW. Although there were no differences in total amino acid levels, the free amino acid content of SW was approximately 4-fold higher than that of wild type, and the levels of certain free amino acids such as proline were particularly high. Thus, we were able to clearly demonstrate that the lack of GBSSI and SSIIa caused dramatic changes in mature seed composition in SW. These compositional changes suggest that SW flour may provide health benefits when used as a food ingredient.  相似文献   

Cloning and characterization of a NADP+-malic enzyme gene from Bradyrhizobium japonicum USDA110     

Suphawat Sinsuwongwat  Amane Kodera  Takakazu Kaneko  Satoshi Tabata  Mika Nomura  Shigeysuki Tajima 《Soil Science and Plant Nutrition》2013,59(5):711-717

Malic enzymes have been considered to play a key role in energy metabolism for nitrogenase reaction in bacteroids. To elucidate the physiological role of the malic enzymes in Bradyrhizobium japonicum bacteroids, a putative malic enzyme gene Bjtme1 was cloned by polymerase chain reaction (PCR) using degenerated primers from conserved regions of the protein sequences of bacterial malic enzymes and draft sequence data of the Bradyrhizobium japonicum USDA110 genome sequence project. To confirm the characteristics of the Bjtme1 gene, the protein encoded by this gene was over-expressed using a pET32a(+) system and it exhibited a NADP⁺-malic enzyme (EC 1.1.1.40) activity, indicating that Bjtme1 was the gene of the NADP⁺-malic enzyme. This is the first report on the cloning and characterization of the NADP⁺-malic enzyme gene from B. japonicum, and the gene structure was compared with that of NADP⁺-malic enzyme genes of other rhizobia.  相似文献   

Shear strength and perpendicular-to-grain tensile strength of defect-free Scots pine wood from mature stands in Finland and Sweden     

Mika Grekin  Thibaud Surini 《Wood Science and Technology》2008,42(1):75-91

Variations in parallel-to-grain static shear strength and perpendicular-to-grain tensile strength of Scots pine wood from mature stands in Finland and Sweden were studied by means of linear mixed model analyses. Approximately 35% of the total variation in shear strength could be described with readily available independent background variables; if the basic density was included, approximately two-thirds of the total variation could be controlled. In tensile strength perpendicular to grain, only approximately one-fourth of the total variation could be described with the respective background variables; the property was found to be independent on wood density, and the reasons for the absence of strength–density relationship are discussed.  相似文献   

Innovation Expectations and Patenting in Private and Public R&D Projects          下载免费PDF全文

Mika Haapanen  Helena Lenihan  Anu Tokila 《Growth and change》2017,48(4):744-768

In this paper, we investigate how the innovation expectations of public financiers are related to realized patents. The analysis is based on a novel data set of collaborative R&D projects subsidized by the Finnish Agency of Technology and Innovation (Tekes) and the European Regional Development Fund (ERDF) during the period 2000–2004. Innovation expectations are measured using reports submitted by Tekes experts during ex ante assessments of projects. Our probit model results reveal that Tekes' patent expectations are positively related to realized patents for projects led by private firms (but not by public organizations). For large organizations, Tekes' innovation expectations are better at predicting patenting.  相似文献   

Fluxes of nitrous oxide and nitric oxide from experimental excreta patches in boreal agricultural soil     

Marja Maljanen  Mika Martikkala  Perttu Virkajärvi 《Soil biology & biochemistry》2007,39(4):914-920

Nitric oxide (NO) and nitrous oxide (N₂O) emissions were measured from experimental dung and urine patches placed on boreal pasture soil during two growing seasons and one autumn period until soil freezing. N₂O emissions in situ were studied by a static chamber method. NO was measured with a dynamic chamber method using a NO analyser in situ. Mean emissions from the control plots were 47.6±4.5 μg N₂ON m⁻² h⁻¹ and 12.6±1.6 μg NON m⁻² h⁻¹. N₂O and NO emissions from urine plots (132±21.2 μg N₂ON m⁻² h⁻¹ and 51.9±7.6 μg NON m⁻² h⁻¹) were higher than those from dung plots (110.0±20.1 μg N₂ON m⁻² h⁻¹ and 14.7±2.1 μg NON m⁻² h⁻¹). There was a large temporal variation in N₂O and NO emissions. Maximum N₂O emissions were measured a few weeks after dung or urine application, whereas the maximum NO emissions were detected the following year. NO was responsible on average 14% (autumn) and 34% (summer) of total (NO+N₂O)N emissions from the pasture soil. NO emissions increased with increasing soil temperature and with decreasing soil moisture. N₂O emissions increased with increasing soil moisture, but did not correlate with soil temperature. Therefore we propose that N₂O and NO were produced mainly during different microbial processes, i.e., nitrification and denitrification, respectively. The results show that the overall conditions and mechanism especially for emissions of NO are still poorly understood but that there are differences in the mechanisms regulating N₂O and NO production.  相似文献   

The effect of sex hormones on total immunoglobulin level in the serum of moulting hens     

S Bobek  M Mika  J Niezgoda  K Pierzcha?a 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1985,32(8):633-635

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