Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequency     

W Kaczmarek‐Derda  L strem  M Myromslien  L O Brandster  J Netland 《Weed Research》2019,59(1):67-76

Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost‐effective means to control rushes. In a field experiment in western Norway, we investigated development of above‐ and below‐ground fractions of rush from seedlings to three‐year‐old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above‐ground:below‐ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below‐ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.  相似文献   

Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice     

Pedro Soler-Lloréns  Yolanda Gil-Ramírez  Ana Zabalza-Baranguá  Maite Iriarte  Raquel Conde-álvarez  Amaia Zú?iga-Ripa  Beatriz San Román  Michel S Zygmunt  Nieves Vizcaíno  Axel Cloeckaert  María-Jesús Grilló  Ignacio Moriyón  Ignacio López-Go?i 《Veterinary research》2014,45(1):72

Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.  相似文献   

Purification of chinook salmon (Oncorhynchus tshawytscha) GH for receptor study     

Pierre-Yves Le Bail  Geneviève Boulard  Bruno Barenton  Michel Zygmunt 《Fish physiology and biochemistry》1989,7(1-6):243-251

A method for the purification of chinook Salmon (Oncorhynchus tshawytscha) GH, which retains its biological activity, is described. The biological activity was investigated with an established radioreceptor assay using liver membranes from pregnant rabbits and bovine GH as standard and labelled hormone. The enrichment of the preparation was checked with electrophoresis (SDS-PAGE). Extraction and further steps were carried out using low molarity alkaline buffer (pH 8–10, M = 100 mM). Three chromatography steps were performed (Concanavalin-A sepharose, Bio-gel P60, DEAE). Ion exchange chromatography was performed under isocratic conditions (using a 50 cm column). Two isoforms (sGH1 and sGH2) were isolated. The purification yield is 0.7% compared to lyophilized pituitaries. The molecule is homogeneous in SDS-PAGE. Contamination by prolactin, gonadotrophin and corticotrophin is negligible (< 0.5%). It could be demonstrated that the biological activity of the preparation is maintained since this preparation stimulates the growth of juvenile trout (Salmo gairdneri) and binds specifically (35%) to trout liver membranes.  相似文献   

The involvement of the anterior cingulate cortex in remote contextual fear memory   总被引：1，自引：0，他引：1  

Frankland PW  Bontempi B  Talton LE  Kaczmarek L  Silva AJ 《Science (New York, N.Y.)》2004,304(5672):881-883

Although the molecular, cellular, and systems mechanisms required for initial memory processing have been intensively investigated, those underlying permanent memory storage remain elusive. We present neuroanatomical, pharmacological, and genetic results demonstrating that the anterior cingulate cortex plays a critical role in remote memory for contextual fear conditioning. Imaging of activity-dependent genes shows that the anterior cingulate is activated by remote memory and that this activation is impaired by a null alpha-CaMKII mutation that blocks remote memory. Accordingly, reversible inactivation of this structure in normal mice disrupts remote memory without affecting recent memory.  相似文献   

Retraction     

Flavell RA  Kaczmarek LK  Badou A  Boulpaep EL  Desai R  Basavappa S  Matza D  Peng YQ  Mehal WZ 《Science (New York, N.Y.)》2005,310(5756):1903

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Protection of Groundwater from Migration of Infiltrates from a Chromic Waste Storage Site and Methods of Treating these Infiltrates     

Kowalski  Zygmunt  Kozak  Adam 《Water, air, and soil pollution》2001,128(1-2):115-137

This work presents the results ofinvestigations to develop and implement methods toeffectively collect and purify infiltrates from heaps,situated in the region of Alwernia near Cracow, wheremore than 3 million tonnes of waste material resultingfrom the production of chromium compounds have beenstored. It describes a system for the protection ofgroundwater from these infiltrates which contain 50–400 g m^-3 Cr⁶⁺, as well as the effectivenessof cheap and simple chemical methods to purify thesechromic wastewaters. The infiltrate collection systemand the most effective method to decrease theconcentration of Cr⁶⁺ to a level below 0.1 ppm,as required by Polish and European Union regulations,were implemented in the Alwernia Chemical Works S.A.in the years 1998–1999.  相似文献   

Population dynamics of the potato cyst nematode,Globodera pallida,in relation to temperature,potato cultivar and nematicide application     

A. M. Kaczmarek  M. Back  V. C. Blok 《Plant pathology》2019,68(5):962-976

The impact of increasing temperatures on the population dynamics of the soil-dwelling nematode Globodera pallida, a persistent and economically important pest of potatoes, was investigated. The reproductive factor (final population⁄initial population) and length of life cycle were found to be temperature sensitive. Pot experiments performed over 4 months allowed comparison of the effect on development of G. pallida of two temperature regimes: an average temperature comparable to current field conditions (14.3 °C) and an average temperature above current field conditions (17.3 °C). A larger second generation of juveniles was observed at 17.3 °C compared to 14.3 °C. Multiplication of G. pallida at field sites in Shropshire and East Lothian (average soil temperatures of 15.5 and 14.1 °C, respectively, during potato cropping) was also examined. A quantitative PCR assay and visual examination of roots were used to monitor the dynamics of the G. pallida populations in both field sites at 4-weekly intervals. Four cultivars, Desirée, Cara, Maris Piper and Estima, were grown with and without nematicide treatments. Nematicide treatments suppressed population increases at both sites. Females were observed on the roots of cvs Cara and Desirée at the end of the growing season in Shropshire, but not at East Lothian, and are likely to represent a second generation.  相似文献   

Tulathromycin enhances humoral but not cellular immune response in pigs vaccinated against swine influenza     

Ma&#x;gorzata Pomorska‐Ml  Krzysztof Kwit  Ewelina Czyewska‐Dors  Zygmunt Pejsak 《Journal of veterinary pharmacology and therapeutics》2019,42(3):318-323

The effect of a standard, single dose therapy with tulathromycin was investigated on the postvaccinal humoral and cellular immune response in pigs vaccinated against swine influenza. Forty‐five pigs, divided into 3 groups, were used (control not vaccinated (C, n = 15), control vaccinated (CV, n = 15), and experimentally received tulathromycin (TUL, n = 15)). For vaccination of pigs, an inactivated, commercial vaccine was used. Pigs from TUL group received single dose of tulathromycin intramuscularly, at the recommended dose (2.5 mg/kg body weight). Pigs from TUL and CV groups were vaccinated at 8 and 10 weeks of age. The specific humoral and cellular immune response against swine influenza virus (SIV) was evaluated. The results of present study showed that humoral postvaccinal response after vaccination against SIV can be modulated by treatment with tulathromycin. In pigs from TUL group, the significantly higher titers of anti‐SIV‐specific antibodies were observed 4 and 6 weeks after booster dose of vaccine. Simultaneously, T‐cell‐mediated immune response against SIV was not affected by tulathromycin. Our recent study confirmed the importance of defining the modulatory activity of tulathromycin because of its influence on the immune response to vaccines. Since the antibodies against hemagglutinin are crucial for the protection against SIV, the present observations should prompt further studies on the practical significance of recent results in terms of clinical implications (postvaccinal protection) in the field conditions.  相似文献   

Wear of spring tine cultivator points in sandy loam and light clay soils in southern Poland     

Zygmunt Owsiak 《Soil & Tillage Research》1999,50(3-4)

Correct evaluation and forecasting of durability of soil cutting parts are the decisive factors for proper operation of agricultural machinery. During operation of cultivators, over two-fold difference in wear of cultivator points is observed, which makes establishing of their exchange periods extremely difficult. So, there is a need to conduct some research aimed for determination of relationship between arrangement of the points in individual cultivator rows and their wear. The presented experiments were performed under authentic farm conditions during spring soil loosening and levelling operations before sowing and planting, in sandy loam and light clay soils. Changes in length and thickness of the spring tine points, wear patterns and weight loss were measured. Loss in length of spring tine points was described by a complex function of the distance travelled or by an exponential function of the distance from the measuring point to the symmetry axis of a spring tine point; loss in thickness was described by a linear function. It was found that soil type, as well as arrangement of the points in individual cultivator rows and their position in relation to the tractor wheel track, significantly influenced their wear. It was also observed that wear of spring tine points was 40–100% higher in the sandy loam soil than in the light clay soil, and that wear within a tractor wheel track was 17–40% higher than outside the track. Moreover, wear of points positioned in the first row on the cultivator frame was 26–100% higher than wear of those in the third row. The research results emphasise the need for field experiments at compare wear of spring tine points made of different materials or of different designs to take into account differences in wear due to positioning of the points on cultivator frames.  相似文献   

Characterisation of Ramularia collo‐cygni laboratory mutants resistant to succinate dehydrogenase inhibitors          下载免费PDF全文

Marta J Piotrowska  James M Fountaine  Richard A Ennos  Maciej Kaczmarek  Fiona J Burnett 《Pest management science》2017,73(6):1187-1196

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