322 resultados para tiller


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Se examina la descentralización del sistema educativo noruego. Con la descentralización las escuelas reciben un mandato de desarrollo más amplio que exige el aumento y la autoimposición de una evaluación y un control cualitativos. Se exponen las condiciones básicas para que la escuela pueda gestionar satisfactoriamente esas tareas y algunos consejos para profesores y autoridades escolares. Se examinan la utilidad y las ventajas de esta descentralización en relación con el carácter y los objetivos peculiares de la escuela noruega.

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Investigations were conducted during the 2003, 2004 and 2005 growing seasons in northern Greece to evaluate effects of tillage regime (mouldboard plough, chisel plough and rotary tiller), cropping sequence (continuous cotton, cotton-sugar beet rotation and continuous tobacco) and herbicide treatment on weed seedbank dynamics. Amaranthus spp. and Portulaca oleracea were the most abundant species, ranging from 76% to 89% of total weed seeds found in 0-15 and 15-30 cm soil depths during the 3 years. With the mouldboard plough, 48% and 52% of the weed seedbank was found in the 0-15 and 15-30 cm soil horizons, while approximately 60% was concentrated in the upper 15 cm soil horizon for chisel plough and rotary tillage. Mouldboard ploughing significantly buried more Echinochloa crus-galli seeds in the 15-30 cm soil horizon compared with the other tillage regimes. Total seedbank (0-30 cm) of P. oleracea was significantly reduced in cotton-sugar beet rotation compared with cotton and tobacco monocultures, while the opposite occurred for E. crus-galli. Total seed densities of most annual broad-leaved weed species (Amaranthus spp., P. oleracea, Solanum nigrum) and E. crus-galli were lower in herbicide treated than in untreated plots. The results suggest that in light textured soils, conventional tillage with herbicide use gradually reduces seed density of small seeded weed species in the top 15 cm over several years. In contrast, crop rotation with the early established sugar beet favours spring-germinating grass weed species, but also prevents establishment of summer-germinating weed species by the early developing crop canopy.

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The impact of parasitoids on pests varies between conventional and low-intensity agricultural systems. Although the impacts on parasitoid natural enemies of many practices within these agricultural systems are well understood, the role of fertilisers has been less well studied. The effects of organic-based and conventional fertilisers on Hordeum vulgare L. (Poaceae), the aphid Metopolophium dirhodum Walker (Hemiptera: Aphididae), and its parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) was investigated using cage release experiments and measures of aphid and parasitoid fitness were taken. Barley tiller number and aphid weight were increased by fertilisers, particularly under conventional treatments. Adult parasitoid size correlated positively with that of the host, M. dirhodum, whereas percentage parasitism was not affected by fertiliser treatment or host size. The results suggest that the increased parasitoid impact observed in some low-intensity or organic systems is not a direct result of fertiliser treatment. Our results indicate that fertiliser treatments that improve cereal-aphid fitness will improve parasitoid fitness as measured by parasitoid size but may not influence percentage parasitism.

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Genetic modification of shoot and root morphology has potential to improve water and nutrient 19 uptake of wheat crops in rainfed environments. Near-isogenic lines (NILs) varying for a tillering 20 inhibition (tin) gene and representing multiple genetic backgrounds were investigated in contrasting 21 controlled environments for shoot and root growth. Leaf area, shoot and root biomass were similar 22 until tillering whereupon reduced tillering in tin-containing NILs produced reductions of up to 60% in 23 total leaf area and biomass, and increases in total root length of up to 120% and root biomass to 24 145%. Together, root-to-shoot ratio increased two-fold with the tin gene. The influence of tin on shoot 25 and root growth was greatest in the cv. Banks genetic background, particularly in the biculm-selected 26 NIL, and was typically strongest in cooler environments. A separate de-tillering study confirmed 27 greater root-to-shoot ratios with regular tiller removal in non-tin containing genotypes. In validating 28 these observations in a rainfed field study, the tin allele had a negligible effect on seedling growth but 29 was associated with significantly (P<0.05) reduced tiller number (-37%), leaf area index (-26%) and 30 spike number (-35%) to reduce plant biomass (-19%) at anthesis. Root biomass, root-to-shoot ratio at 31 early stem elongation and root depth at maturity were increased in tin-containing NILs. Soil water use 32 was slowed in tin-containing NILs resulting in greater water availability, greater stomatal 33 conductance, cooler canopy temperatures and maintenance of green leaf area during grain-filling. 34 Together these effects contributed to increases in harvest index and grain yield. In both the controlled 35 and field environments, the tin gene was commonly associated with increased root length and biomass 36 but the significant influence of genetic background and environment suggests careful assessment of 37 tin-containing progeny in selection for genotypic increases in root growth.

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In addition to their expected effects on lipid profile, lipid-lowering agents may reduce cardiovascular events because of effects on nonclassic risk factors such as insulin resistance and inflammation. Ezetimibe specifically blocks the absorption of dietary and biliary cholesterol as well as plant sterols. Although it is known that an additional reduction of low-density lipoprotein cholesterol (LDL-C) levels can be induced by the combination of ezetimibe with statins, it is not known if this can enhance some pleiotropic effects, which may be useful in slowing the atherosclerotic process. This study assessed the effects of simvastatin and ezetimibe, in monotherapy or in combination, on markers of endothelial function and insulin sensitivity. Fifty prediabetic subjects with normo- or mild-to-moderate hypercholesterolemia were randomly allocated to 2 groups receiving either ezetimibe (10 mg/d) or simvastatin (20 mg/d) for 12 weeks, after which the drugs were combined for both groups for an additional 12-week period. Clinical and laboratory parameters were measured at baseline and after 12 and 24 weeks of therapy. Homeostasis model assessment of insulin resistance index and the area under the curve of insulin were calculated. As expected, both groups receiving drugs in isolation significantly reduced total cholesterol, LDL-C, apolipoprotein B, and triglyceride levels; and additional reductions were found after the combination period (P <.05). After 12 weeks of monotherapy, plasminogen activator inhibitor-1 levels and urinary albumin excretion were lower in the simvastatin than in the ezetimibe group. No change in homeostasis model assessment of insulin resistance index, area under the curve of insulin, and adiponectin levels was observed tiller either the monotherapies or the combined therapy. However, simvastatin combined with ezetimibe provoked significant reductions in E-selectin and intravascular cellular adhesion molecule-1 levels that were independent of LDL-C changes. Our findings support claims that simvastatin may be beneficial in preserving endothelial function in prediabetic subjects with normo- or mild-to-moderate hypercholesterolemia. Alternatively, a deleterious effect of ezetimibe on the endothelial function is suggested, considering the increase in intravascular cellular adhesion molecule I and E-selectin levels. Simvastatin and ezetimibe, in isolation or in combination, do not interfere with insulin sensitivity. (C) 2010 Elsevier Inc. All rights reserved.

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När samhället blir mera komplext ställs generellt sett allt större krav på enskilda individer och organisationer. Detta innebär också att t ex kraven på skolan som organisation ökar i motsva-rande grad. Om förändringar i skolan skall lyckas måste lärarna involveras (Hargreaves, 1998). Förändringen måste helt enkelt utgå från lärarna själva. “It is teachers who, in the end, will change the world of the school by understanding it“ (Lawrence Stenhouse, citerad i Egerbladh & Tiller, 1998). För många lärare är kärnpunkten när verksamheten skall förändras om den går att genomföra i praktiken. På det sätt som lärare förstår hur skolan fungerar kan även antas ha betydelse för hur de utför sina arbetsuppgifter. Det är mot en sådan bakgrund som s k forskningscirklar, som ett forum för ett möte mellan lärare och forskare, blir av intresse. Kan då också s k lärande organisationer innehålla forskningscirklar som en möjlig arbetsform för att både förstå och att utveckla skolans verksamhet i praktiken? Med utgångspunkt från den bakgrund som skisserats upp är syftet med detta paper sålunda att diskutera: a) Under vilka förutsättningar är det möjligt att tala om skolan som en lärande organisa-tion?b) Är det möjligt att betrakta forskningscirkeln som ett, av flera tänkbara, medel för att utveckla skolan mot en lärande organisation?Jag utgår från två av Senges (1995) huvudkriterier, personlig utveckling (Personal Mastery) och team-lärande, för att diskutera några aspekter av de frågeställningar som anges i syftet. För att ge en mer fullständig bild skulle det självfallet ha varit att föredra att de tre övriga kriterierna som Senge använder hade kunnat behandlas på ett motsvarande sätt. Jag väljer dock bort dessa då det inte finns möjlighet att klara av en sådan uppgift inom den begränsade ram som ett paper av den här typen ger utrymme för.

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We screened seaweed species from Atlantic Canada for antidiabetic activity by testing extracts for α-glucosidase inhibitory effect and glucose uptake stimulatory activity. An aqueous ethanolic extract of Ascophyllum nodosum was found to be active in both assays, inhibiting rat intestinal α-glucosidase (IC50 = 77 μg/mL) and stimulating basal glucose uptake into 3T3-L1 adipocytes during a 20-minute incubation by about 3-fold (at 400 μg/mL extract). Bioassay-guided fractionation of the A. nodosum extract showed that α-glucosidase inhibition was associated with polyphenolic components in the extract. These polyphenolics, along with other constituents appeared to be responsible for the stimulatory activity on glucose uptake. However, attempts to further concentrate this activity through fractionation techniques were unsuccessful. A crude polyphenol extract (PPE), an enriched polyphenolic fraction (PPE-F1) and a polysaccharide extract (PSE) were prepared from commercial A. nodosum powder and administered to streptozotocin-diabetic mice for up to 4-weeks by daily gavage at 200 mg/kg body mass. PPE and PPE-F1 improved fasting serum glucose level in diabetic mice; however, the effect was only statistically significant at day 14. In addition, PPE-F1 was shown to blunt the rise in blood glucose after an oral sucrose tolerance test in diabetic mice. Mice treated with PPE and PPE-F1 had decreased blood total cholesterol and glycated serum protein levels compared with untreated diabetic mice, whereas PPE also normalized the reduction in liver glycogen level that occurred in diabetic animals. All 3 A. nodosum preparations improved blood antioxidant capacity.

On a établit une recherche d’un produit anti-diabétique, parmi les algues locales de la région Atlantique du Canada, en examinant la capacité d’un effet inhibiteur de l’enzyme α-glucosidase et une stimulation de l’incorporation cellulaire du glucose. Un extrait éthanol-aqueux de Ascophyllum nodosum nous a donné une activité positive chez les deux essais, une inhibition de l’α-glucosidase provenant de l’intestin du rat (IC50 = 77 μg/mL) et puis une stimulation triple, à une concentration de 400 μg/mL, de l’incorporation du glucose dans les adipocytes 3T3-L1 durant une période de 20 minutes. L’extrait de A. nodosum a été divisé, guidé par les résultats biologiques, et a ainsi démontré la présence d’éléments polyphénoliques associé à l’inhibition de l’α-glucosidase. Ces éléments polyphénoliques ainsi que d’autres semblent être responsables de l’incorporation stimulée du glucose. Il a été impossible de raffiner cette activité lors d’une division des composants. Un extrait brut polyphénolique (PPE), un extrait enrichi polyphénolique (PPE-F1) et puis un extrait polysaccharide (PSE) furent préparés d’une poudre commerciale de A. nodosum et utilisés dans une étude utilisant des souris, rendues diabétiques par injections de streptozotocin, traitées par un gavage journalier de l’extrait 200 mg/kg du poids corporel durant une période de 4 semaines. Le taux du glucose sanguin à jeun des souris fut moins élevé en présence des extraits qu’en leurs absence. Cependant, l’effet était seulement significatif au jour 14. Les résultats étant toutefois variables. En plus, lors d’un essai oral de la tolérance au sucrose chez la souris diabétique, l’extrait PPE-F1 a empêché l’augmentation du taux du glucose sanguin. Les extraits PPE et PPE-F1 ont réduit le taux de cholestérol sanguin et les niveaux de glycation des protéines en comparaison de ces niveaux en absence des extraits tandis que l’extrait PPE a présenté une réduction du niveau de glycogène du foie chez les souris diabétiques. Les trois extraits de A. nodosum ont tous amélioré la capacité antioxidante du sang.

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A salmon protein hydrolysate (SPH) was developed containing several angiotensin I-converting enzyme (ACE) inhibitory tripeptides the most abundant of which were Val-Leu-Trp, Val-Phe-Tyr, and Leu-Ala-Phe. Simulated digestion experiments showed that active constituents of SPH would survive in the digestive tract and be available for absorption into the bloodstream. In fact, ACE inhibitory activity was improved following simulated digestion suggesting that there were larger peptides in SPH that might contribute to bioactivity in vivo. A single oral dose (1,500 mg/kg body mass) of SPH significantly lowered blood pressure in spontaneously hypertensive rats (SHR). The treatment of SHR with either SPH fraction (<3,000 Da) or SPH fraction (>3,000 Da) reduced blood pressure. We conclude that the ability of SPH to lower blood pressure is due to a combination of ACE inhibitory tripeptides as identified, as well as additional unknown, peptide species that are generated during digestion of SPH in the gastrointestinal tract.

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Though prevalent in both genders, specific consideration needs to be given when treating a woman suffering from bipolar disorder over her lifetime. Bipolar disorder is a serious and incapacitating illness affecting an estimated 5% of women. The first episode of illness in women is usually a depressive episode. Female gender has been associated with greater axis-one comorbidity, more depressive episodes, rapid cycling and mixed affective states. Special consideration is required for the treatment of bipolar disorder during reproductive events. More studies are required to better understand the course, outcome and gender-specific treatment strategies of this disorder.

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The red alga, Furcellaria lumbricalis from the coast of the Prince Edward Island (PEI) in Atlantic Canada, was extracted with hot water and fractionated with 0.125. M KCl to obtain a carrageenan-like polysaccharide. The polysaccharide was further purified on ion-exchange and gel-permeation chromatography to yield a fraction (FB1) of uniform size and charge, with an average molecular weight of 428. kD. Oligosaccharides generated with acid hydrolysis of FB1 were sequenced using the electrospray ionisation collision induced dissociation tandem mass spectrometry (ES-CID-MS/MS) technique. On the basis of chemical and spectroscopic analysis, FB1 was characterised to be composed of 1,4-linked 3,6-anhydro-galactose (40%), 1,3-linked 4-sulphated-galactose (30%), 1,3-linked galactose (20%), 1,4-linked galactose (8%) and 1,4-linked 3-O-methyl-galactose (2%), which makes it be a novel sulphated galactan hybrid. The β-secretase (BACE) inhibition and immunomodulation activities of FB1-derived oligosaccharides were evaluated in vitro.

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Objective: This paper aims to present an overview of screening and safety considerations for the treatment of clinical depressive disorders and make recommendations for safety monitoring.
Method: Data were sourced by a literature search using MEDLINE and a manual search of scientific journals to identify relevant articles. Draft guidelines were prepared and serially revised in an iterative manner until all co-authors gave final approval of content.
Results: Screening and monitoring can detect medical causes of depression. Specific adverse effects associated with antidepressant treatments may be reduced or identified earlier by baseline screening and agent-specific monitoring after commencing treatment.
Conclusion: The adoption of safety monitoring guidelines when treating clinical depression is likely to improve overall physical health status and treatment outcome. It is important to implement these guidelines in the routine management of clinical depression.

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Background: Since the mid-1990s, early dialysis initiation has dramatically increased in many countries. The Initiating Dialysis Early and Late (IDEAL) study demonstrated that, compared with late initiation, planned early initiation of dialysis was associated with comparable clinical outcomes and increased health care costs. Because residual renal function is a key determinant of outcome and is better preserved with peritoneal dialysis (PD), the present pre-specified subgroup analysis of the IDEAL trial examined the effects of early-compared with late-start dialysis on clinical outcomes in patients whose planned therapy at the time of randomization was PD.

Methods: Adults with an estimated glomerular filtration rate (eGFR) of 10 - 15 mL/min/1.73 m2 who planned to be treated with PD were randomly allocated to commence dialysis at an eGFR of 10 - 14 mL/min/1.73 m2 (early start) or 5 - 7 mL/min/1.73 m2 (late start). The primary outcome was all-cause mortality.

Results: Of the 828 IDEAL trial participants, 466 (56%) planned to commence PD and were randomized to early start (n = 233) or late start (n = 233). The median times from randomization to dialysis initiation were, respectively, 2.03 months [interquartile range (IQR):1.67 - 2.30 months] and 7.83 months (IQR: 5.83 - 8.83 months). Death occurred in 102 early-start patients and 96 late-start patients [hazard ratio: 1.04; 95% confidence interval (CI): 0.79 - 1.37]. No differences in composite cardiovascular events, composite infectious deaths, or dialysis-associated complications were observed between the groups. Peritonitis rates were 0.73 episodes (95% CI: 0.65 - 0.82 episodes) per patient-year in the early-start group and 0.69 episodes (95% CI: 0.61 - 0.78 episodes) per patient-year in the late-start group (incidence rate ratio: 1.19; 95% CI: 0.86 - 1.65; p = 0.29). The proportion of patients planning to commence PD who actually initiated dialysis with PD was higher in the early-start group (80% vs 70%, p = 0.01).

Conclusion: Early initiation of dialysis in patients with stage 5 chronic kidney disease who planned to be treated with PD was associated with clinical outcomes comparable to those seen with late dialysis initiation. Compared with early-start patients, late-start patients who had chosen PD as their planned dialysis modality were less likely to commence on PD.

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OBJECTIVE: Depression is the predominant psychosocial and suicide burden in bipolar disorder, yet there is a paucity of evidence-based treatments for bipolar depression. METHODS: This post hoc subgroup analysis of data pooled from two 3-week, randomized, placebo- and olanzapine-controlled trials (December 2004-April 2006, N = 489 and November 2004-April 2006, N = 488) examined a subgroup of patients meeting criteria for moderate-to-severe mixed major depressive episodes, defined using DSM-IV-TR criteria for mixed episodes (mania and major depression simultaneously) with a baseline Montgomery-Asberg Depression Rating Scale (MADRS) total score ≥ 20. RESULTS: Decreases in MADRS scores (least squares mean [SE]), the a priori primary outcome, were significantly greater in the asenapine group than in the placebo group from baseline to day 7 (-11.02 [1.82] vs -4.78 [1.89]; P = .0195), day 21 (-14.03 [2.01] vs -7.43 [2.09]; P = .0264), and endpoint (-10.71 [1.76] vs -5.19 [1.98]; P = .039). Decreases in MADRS scores with asenapine were significantly greater than with olanzapine from baseline to day 7 (-6.26 [1.47]; P = .0436). Decreases in Young Mania Rating Scale mean total score were greater with asenapine than with placebo or olanzapine at all time points assessed. A significantly greater reduction from baseline to day 21 in the Short Form-36 mental component summary score was observed with asenapine, but not olanzapine, compared with placebo (16.57 vs 5.97; P = .0093). Asenapine was generally well tolerated. CONCLUSIONS: These data provide support for the potential efficacy of asenapine in mixed major depressive episodes; however, these data cannot be linearly extrapolated to nonmixed major depression.