837 resultados para Fertilization Success
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Recently considerable research has focused on the causes of evolution of multiple-queen (polygynous) colonies. In order to better understand the factors which may have led to these polygynous associations it is vital to compare the reproductive success of queens in monogynous (one queen per colony) and polygynous colonies as well as the relative fitness of queens in polygynous colonies. This paper addresses the difficulties arising from such comparisons and their implications with regard to the methods commonly used to assess reproductive success in queens. The relative reproductive success of queens in monogynous and polygynous colonies is commonly assessed by comparing the relative number of reproductives they produce during a single reproductive season. However, shift in queen number seems to be only one aspect of a profound shift in social structure and reproductive strategy that constitutes, in effect, a ''polygyny syndrome''. For example, female reproductives produced in polygynous colonies frequently use a different mode of colony founding, which in turn affects the probability of their survival. Furthermore, queens from monogynous and polygynous colonies frequently differ in their life-span and the number of sexual broods they produce. As a result, the reproductive success of queens in monogynous and polygynous colonies may not be directly related to the relative number of sexuals they produce during a single reproductive season.
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Background Dugesia sicula is the only species of its genus not presenting an endemic or restricted distribution within the Mediterranean area. It mostly comprises fissiparous populations (asexual reproduction by body division and regeneration), most likely sexually sterile, and characterized by an extremely low genetic diversity interpreted as the consequence of a recent anthropic expansion. However, its fissiparous reproduction can result in an apparent lack of diversity within the species, since genetic variation within individuals can be as large as between them because most individuals within a population are clones. We have estimated haplotype and nucleotide diversity of cytochrome oxidase I within and among individuals along the species distribution of a broad sample of D. sicula, including asexual and the two only sexual populations known today; and predicted its potential distribution based on climatic variables. Our aim was to determine the centre of colonisation origin, whether the populations are recent, and whether the species is expanding. Results The species presents 3 most frequent haplotypes, differing in a maximum of 11 base pairs. As expected from their fissiparous mode of reproduction, in half of all the analysed localities many individuals have multiple heteroplasmic haplotypes. The distribution of haplotypes is not geographically structured; however, the distribution of haplotypes and heteroplasmic populations shows higher diversity in the central Mediterranean region. The potential distribution predicted by climatic variables based modelling shows a preference for coastal areas and fits well with the observed data. Conclusions The distribution and frequency of the most frequent haplotypes and the presence of heteroplasmic individuals allow us to gain an understanding of the recent history of the species, together with previous knowledge on its phylogenetic relationships and age: The species most probably originated in Africa and dispersed through the central Mediterranean. After one or multiple populations became triploid and fissiparous, the species colonized the Mediterranean basin, likely both by its own means and helped by human activities. Its present distribution practically fulfils its potential distribution as modelled with climatic variables. Its prevalence in coastal regions with higher water temperatures predicts a likely future expansion to northern and more interior areas following the increase in temperatures due to climate change.
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Abstract
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The objective of this work was to evaluate the effect on forage yield of sowing winter forage species before and after soybean harvest, at different nitrogen application levels. The experiment was set out in a randomized block design with a strip-split plot arrangement, and three replicates. Sowing methods (18 days before soybean harvest and six days after soybean harvest) were allocated in the main plots, and the combination among forage species (Avena strigosa cv. IAPAR 61 + Lolium multiflorum; A. strigosa cv. Comum + L. multiflorum; A. strigosa cv. Comum + L. multiflorum + Vicia villosa; A. strigosa cv. Comum + L. multiflorum + Raphanus sativus; and L. multiflorum) and nitrogen levels (0, 140, 280 and 420 kg ha-1) in the plots and subplots, respectively. Forage sowing before the soybean harvest made it possible to anticipate first grazing by 14 days, with satisfactory establishment of forage species without affecting forage production. This method permitted a longer grazing period, preventing the need for soil disking, besides allowing the use of no-tillage system. The mixture of forage species enables higher forage yield for pasture in relation to single species pastures, with response to nitrogen fertilization up to 360 kg ha-1.
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Abstract Objective: The objective of this retrospective study over a 5-year period was to assess the success rate of airway management by residents. Criteria of successful airway management were both the adherence to a standardized protocol of pre-hospital airway.
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The objective of this work was to assess the effect of poultry litter fertilization levels on corn and black oat yield using different grazing intensities, poultry litter levels (mixture of manure and bedding material) and a chemical fertilization level. The experimental design was a randomized complete block in a split-plot arrangement with four replicates. Black oat + ryegrass grazing intensities, characterized by different pasture sward management, with animal entrance at 25, 30 and 35-cm heights and exit at 5.0, 10 and 15-cm heights, were established at the main plots. After the grazing period, corn was grown at the subplots with four levels of poultry litter (0, 4,953, 9,907 and 14,860 kg ha-1), aiming to supply 0, 100, 200 and 300 kg ha-1 of nitrogen, and a treatment with chemical fertilizer, according to soil analysis. Grazing intensities had no effect on corn yield. Corn yield was 7,493, 8,458, 9,188, 10,247 and 11,028 kg ha-1, respectively, for the treatments without and with 4,953, 9,907 and 14,860 kg ha-1 of poultry litter, and the treatment with chemical fertilization. Poultry litter levels have a residual effect on the production of black oat grown in succession to corn.
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PURPOSE: Acute limb ischemia after thrombosis of a popliteal aneurysm is a distinct and limb-threatening entity. Preoperative intra-arterial thrombolysis may improve the outcome in this challenging situation. This study retrospectively analyzed a consecutive series of patients treated with preoperative thrombolysis and subsequent revascularization. METHODS: Thirteen patients with acute limb ischemia caused by thrombosis of a popliteal aneurysm underwent catheter-directed intra-arterial thrombolysis with urokinase and subsequent vascular reconstruction. The angiographic and clinical outcome was analyzed and compared with that in the literature. RESULTS: Complete aneurysm thrombosis with absence of runoff was documented in 12 cases. Thrombolysis restored perfusion with patency of the popliteal artery and a one- or two-vessel runoff in 77% of cases (10/13). Early cumulative graft patency and limb salvage rates were 68% and 83%, respectively, with an ankle/brachial index of 0.8 +/- 0.2. Lytic failure followed by attempts at bypass grafting was present in three patients (23%) and resulted in above-knee amputation. Severe rhabdomyolysis and fatal pulmonary embolism were responsible for a 15% early mortality rate. CONCLUSION: Preoperative thrombolysis followed by bypass grafting is a valid treatment option for patients who can withstand an additional period of ischemia that does not require immediate revascularization and intraoperative lysis. Lytic failure identifies patients with a highly compromised runoff who are probably best treated by means of subsequent amputation, without any attempts at bypass grafting.
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The objective of this work was to evaluate the agroindustrial production of sugarcane (millable stalks and sucrose yield) after successive nitrogen fertilizations of plant cane and ratoons in a reduced tillage system. The experiment was carried out at Jaboticabal, SP, Brazil, on a Rhodic Eutrustox soil, during four consecutive crop cycles (March 2005 to July 2009). Plant cane treatments consisted of N-urea levels (control, 40, 80, and 120 kg ha-1 N + 120 kg ha-1 P2O5 and K2O in furrow application). In the first and second ratoons, the plant cane plots were subdivided in N-ammonium nitrate treatments (control, 50, 100, and 150 kg ha-1 N + 150 kg ha-1 K2O as top dressing over rows). In the third ratoon, N fertilization was leveled to 100 kg ha-1 in all plots, including controls, to detect residual effects of previous fertilizations on the last crop's cycle. Sugarcane ratoon was mechanically harvested. A weighing truck was used to evaluate stalk yield (TCH), and samples were collected in the field for analysis of sugar content (TSH). Increasing N doses and meteorological conditions promote significant responses in TCH and TSH in cane plant and ratoons, in the average and accumulated yield of the consecutive crop cycles.
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The objective of this work was to measure the fluxes of N2O‑N and NH3‑N throughout the growing season of irrigated common‑bean (Phaseolus vulgaris), as affected by mulching and mineral fertilization. Fluxes of N2O‑N and NH3‑N were evaluated in areas with or without Congo signal grass mulching (Urochloa ruziziensis) or mineral fertilization. Fluxes of N were also measured in a native Cerrado area, which served as reference. Total N2O‑N and NH3‑N emissions were positively related to the increasing concentrations of moisture, ammonium, and nitrate in the crop system, within 0.5 m soil depth. Carbon content in the substrate and microbial biomass within 0.1 m soil depth were favoured by Congo signal grass and related to higher emissions of N2O‑N, regardless of N fertilization. Emission factors (N losses from the applied mineral nitrogen) for N2O‑N (0.01-0.02%) and NH3‑N (0.3-0.6%) were lower than the default value recognized by the Intergovernmental Panel on Climate Change. Mulch of Congo signal grass benefits N2O‑N emission regardless of N fertilization.
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The objective of this work was to evaluate the microbiological and chemical attributes of a soil with a seven‑year history of urea and swine manure application. In the period from October 2008 to October 2009, soil samples were collected in the 0-10 cm layer and were subjected to the treatments: control, without application of urea or manure; and with the application of urea, pig slurry, and deep pig litter in two doses, in order to supply one or two times the recommended N doses for the maize (Zea mays)/black oat (Avena strigosa) crop succession. The carbon of the microbial biomass (MB‑C) and the basal respiration (C‑CO2) were analyzed, and the metabolic (qCO2) and microbial quotient (qmic) were calculated with the obtained data. Organic matter, pH in water, available P and K, and exchangeable Ca and Mg were also determined. The application of twice the dose of deep pig litter increases the MB‑C and C‑CO2 values. The qmic and qCO2 are little affected by the application of swine manure. The application of twice the dose of deep pig litter increases the values of pH in water and the contents of available P and of exchangeable Ca and Mg in the soil.
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Yritykset ovat pakotettuja erilaisiin yhteistyömuotoihin pärjätäkseen kiristyvässä kilpailussa. Yhteistyösuhteet kulkevat eri nimillä riippuen teollisuuden alasta ja siitä, missä kohtaa toimitusketjua ne toteutuvat, mutta periaatteessa kaikki pohjautuvat samaan ideaan kuin Vendor Managed Inventory (VMI); varastoon jakysyntään liittyvä tieto jaetaan toimitusketjun eri osapuolien kesken, jotta tuotanto, jakelu ja varastonhallinta olisi mahdollista optimoida. Vendor Managed Inventory on ideana yksinkertainen, mutta vaatii onnistuakseen paljon. Perusolettamus on, että toimittajan on kyettävä hallinnoimaan asiakkaan varastoa paremmin kuin asiakas itse. Tämä ei kuitenkaan ole mahdollista ilman riittävää yhteistyötä, oikeanlaista informaatiota tai sopivia tuoteominaisuuksia. Tämän työn tarkoitus on esitellä kriittiset menestystekijät valmistajan kannalta, kun näkyvyys todelliseen kysyntään on heikko ja kyseessäolevat tuotteet ovat ominaisuuksiltaan toimintamalliin huonosti soveltuvia. VMItoimintamallin soveltuvuus matkapuhelimia valmistavan yrityksen liiketoimintaan, sekä sen vaikutus asiakasyhteistyöhön, kannattavuuteen ja toiminnan tehostamiseen on myös tutkittu.
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Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems.
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Hyperglycosylated human chorionic gonadotropin (H-hCG) is secreted by the placenta in early pregnancy. Decreased H-hCG levels have been associated with abortion in spontaneous pregnancy. We retrospectively measured H-hCG and dimeric hCG in the sera of 87 in vitro fertilization patients obtained in the 3 weeks following embryo transfer and set the results in relation to pregnancy outcome. H-hCG and dimeric hCG were correlated (r(2) = 0.89), and were significantly decreased in biochemical pregnancy (2 microg/l and 18 IU/l, respectively) compared to early pregnancy loss (22 microg/l and 331 IU/l) and ongoing pregnancy (32 microg/l and 353 IU/l). Only H-hCG tended to discriminate between these last two groups.
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Abstract:The objective of this work was to evaluate the effect of nitrogen fertilization on the growth and yield of arracacha (Arracacia xanthorrhiza), as well as on the plant's nutrient uptake, distribution, and removal. The experiment was carried out in a typical Oxisol, with sandy texture. A randomized complete block design was used, with four replicates. The treatments consisted of five N rates: 0, 50, 100, 200, and 400 kg ha-1. The plots were composed of three 8-m-length rows, spaced at 0.60 m between rows and 0.40 m between plants. The plants were harvested after an 8-month cycle. Nitrogen fertilization significantly increased the proportion of N and S accumulated in stems, and of Ca, Mg, Fe, and Mn in leaves. N supply increased Zn distribution to stems and leaves, whereas high N rates increased Cu allocation to stems more than to the rootstock. High N rates increase plant dry matter (DM) production and nutrient uptake and removal, but do not result in the greatest yield due to the greater development of leaves and stems, and to the lower allocation of DM in storage roots.
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Tässä työssä käsitellään niitä motiiveja, haasteita ja menestystekijöitä, jotka vaikuttavat lisäarvoatuottavassa liiketoimintaverkostossa. Työssä on selvitetty sitä, miten partneriverkostot syntyvät sekä mitkä seikat vaikuttavat siihen jatkuuko yhteistyö vai ei. Motiiveja partneruuteen on tutkittu kirjallisuudesta sekä analysoimalla työssä esitettyä tapausta. Tässä työssä käydään keskustelua myös partneruuden elinkaaresta, jota ei ole käsitellyssä kirjallisuudessa tuotu esille. Työssä esitettyä tapausta arvioitiin lähettämällä siihen liittyneille henkilöille kysely. Kyselyiden lähettämisen jälkeen järjestettiin haastattelu kyselyyn vastanneiden kanssa. Lopputulokset perustuvat pitkälti haastateltujen henkilöiden kanssa käytyihin keskusteluihin. Kävi ilmi, että arvoa tuottavan partneriverkoston yksi tärkeimpiä tavoitteita on saavuttaa jatkuvuutta liiketoiminnallaan. Ainoastaan pitkäaikaisella partneruudella voidaan saavuttaa merkittäviä etuja markkinoilla. Siksi on tärkeätä, jo partnerin valinnassa, kiinnittää huomiota partneruuden jatkuvuuteen pitkällä tähtäimellä. Liiketoimintaverkostossa partneruudesta syntyvät tuotot ja niiden jakaminen on tärkein yksittäinen osaalue. Oleellista partneruuden jatkuvuudelle pitkällä tähtäimellä on jo partneria valittaessa se, että kyetään arvioimaan miten partneruudesta syntyvät tuotot jaetaan tasapuolisesti ja onko partneruudesta syntyvälle liiketoiminnalle jatkuvuutta. Jotta partneriverkostolle asetetut tavoitteet voitaisiin saavuttaa, on tärkeää suunnitella partneriverkoston hallintaa myös operatiivisella tasolla. Lisäksi tärkeää on jakaa verkostolle asetetut yhteiset tavoitteet organisaatioiden sisällä. Jos ylemmänja operatiivisen tason johdon yhteistyö on riittämätöntä, se vaikeuttaa oleellisesti asetettujen tavoitteiden saavuttamista. Tiedon jakaminen aikaisessa vaiheessa sitouttaa eri sidosryhmät paremmin yhteisiin tavoitteisiin.