Thus far but no further: predatory mites do not migrate effectively into strawberry plantations

Enhancing the performance of predatory mites is often regarded as the best biological control approach towards the spider mite Tetranychus urticae, the main pest of strawberry plantations. Optimizing the colonization of plantations by predators from adjacent areas such as field margins is seen as an important component of conservation biocontrol. We have investigated the factors contributing to enhancing the numbers of predatory mites (Acari: Phytoseidae), such as management of the field margins, vegetation composition and the effect of the presence of woody species. We also tested the penetration of the phy-toseiids from the field margins into the crop. In a study carried out in 14 open-field exten-sively managed strawberry plantations in Poland we found phytoseiids to be abundant in field margins; 14 taxa were discovered. However, only two species Amblyseius andersoniand Euseius finlandicus dispersed a modest distance into the crop. We found that the diver-sity and densities of the predatory mites were enhanced somewhat by the management type of the field margins; especially the spontaneous vegetation favoured the presence of phyto-seiids. However, despite the predatory mites being rather retained in the field margins also significant reduction in numbers of their prey T. urticae was recorded over the course of the year. The low penetration of predatory mites into the main part of the field, indicates that conservation biological control measures in the field margin might not be sufficient on their own to enhance the impact of predatory mites within the main part of the fields

Regularizing cosmological singularities by varying physical constants

Varying physical constant cosmologies were claimed to solve standard cosmological problems such as the horizon, the flatness and the $\Lambda$-problem. In this paper, we suggest yet another possible application of these theories: solving the singularity problem. By specifying some examples we show that various cosmological singularities may be regularized provided the physical constants evolve in time in an appropriate way.Comment: 9 pages, 6 figures, Revtex4-1, an improved version to appear in JCA

Centrifugal melt spinning of polyvinylpyrrolidone (PVP)/triacontene copolymer fibres

Polyvinylpyrrolidone/1-triacontene (PVP/TA) copolymer fibre webs produced by centrifugal melt spinning were studied to determine the influence of jet rotation speed on morphology and internal structure as well as their potential utility as adsorbent capture media for disperse dye effluents. Fibres were produced at 72 C with jet head rotation speeds from 7000 to 15,000 r min-1. The fibres were characterised by means of SEM, XRD and DSC. Adsorption behaviour was investigated by means of an isothermal bottle point adsorption study using a commercial disperse dye, Dianix AC-E. Through centrifugal spinning nanofibers and microfibers could be produced with individual fibres as fine as 200–300 nm and mean fibre diameters of ca. 1–2 lm. The PVP/TA fibres were mechanically brittle with characteristic brittle tensile fracture regions observed at the fibre ends. DSC and XRD analyses suggested that this brittleness was linked to the graft chain crystallisation where the PVP/TA was in the form of a radial brush copolymer. In this structure, the triacontene branches interlock and form small lateral crystals around an amorphous backbone. As an adsorbent, the PVP/TA fibres were found to adsorb 35.4 mg g-1 compared to a benchmark figure of 30.0 mg g-1 for a granular-activated carbon adsorbent under the same application conditions. PVP/TA is highly hydrophobic and adsorbs disperse dyes through the strong ‘‘hydrophobic bonding’’ interaction. Such fibrous assemblies may have applications in the targeted adsorption and separation of non-polar species from aqueous or polar environments

The luminosity-redshift relation in brane-worlds: II. Confrontation with experimental data

The luminosity distance - redshift relation for a wide class of generalized Randall-Sundrum type II brane-world models with Weyl fluid is compared to the presently available supernova data. We find that there is a class of spacially flat models with different amounts of matter $\Omega_{\rho}$ and Weyl fluid $\Omega_{d}$, which have a very similar fitting quality. The best-fit models are equally likely and can be regarded as extensions of the $\Lambda$CDM model, which is also included. We examine three models with different evolutionary history of the Weyl fluid, characterized by a parameter $\alpha =0,~2$ and$~3$. The first model describes a brane which had radiated energy into the bulk some time ago, but in recent times this energy exchange has ceased and only a dark radiation ($\alpha =0$) is left. In the other two models the Weyl-fluid describes a radiating brane throughout the cosmological evolution, up to our days. We find that the trought of the fitting surface extends over a wider $\Omega_{d}$-range with increasing $\alpha$, but the linear correlation of $\Omega_{d}$ and $\Omega_{\rho}$ holds all over the examined $\Omega_{d}$ range.Comment: Comparison with observations enhanced as compared to v1 of astro-ph/0606698. Discussion based on Gold2006 data set included, preferred values of cosmological parameters given. Argument supporting a relatively high value of the dark radiation developed. v2: Tests of radiating brane models included, published version (15 pages, 10 figures

Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress

Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress. Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing. Results: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P =.038) and 11% lower concentration of UA (P =.005). TOS was 20% lower (P =.014). The activity of SOD was up to 5% higher (P =.037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity. Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes

Genetically modified plants - from the laboratory to practical application in European agriculture. Part II

Wprowadzanie roślin GM do środowiska jest nie tylko przedmiotem regulacji prawnych, ale również istotną kwestią podlegającą dyskusji naukowej i społecznej. W artykule przedstawiono zasady leżące u podstaw oceny ryzyka związanego ze stosowaniem GMO. Przytoczono wyniki licznych badań nad oddziaływaniem odmian GM dopuszczonych do uprawy na gatunki niedocelowe, obejmujące m.in. różne grupy stawonogów żyjących na uprawach GM i w ich otoczeniu. Dokładniej wyjaśniono przypadek oddziaływania kukurydzy GM na motyla monarcha w USA czy też odmian kukurydzy, buraka i rzepaku tolerujących herbicydy na populacje chwastów i żerujących na nich stawonogach i ptakach. Podkreślono konieczność prowadzenia badań opartych o poprawne metodyki. Podano wyniki pierwszych badań polowych prowadzonych w Polsce nad oddziaływaniem kukurydzy MON 810 na środowisko. Przedstawiono działania Europejskiego Urzędu ds. Bezpieczeństwa Żywności (EFSA) obejmujące: (a) budowanie wzajemnego zrozumienia zasad leżących u podstaw przeprowadzania analizy ryzyka dla nowych GMO i (b) zwiększenie przejrzystości w bieżących pracach pomiędzy państwami członkowskimi UE a urzędem i jego komisjami. Powołanie Naukowej Sieci krajowych ekspertów (EFSA Scientific Network) ma tę współpracę zapewnić. Podsumowano podstawy wykrywania i kontroli GMO w laboratoriach referencyjnych w Europie.The release of genetically modified plants into the environment is not only a subject of legal regulations, but also an important subject matter of the scientific and social debate. The article presents rules forming the basis of the risk assessment related to use of GMOs. It quotes the results of numerous studies concerning the impact of GMO varieties approved for cultivation on the nontarget species, including i.a. various groups of arthropods living in the area of GMO crops and in their vicinity. It also offers more precise explanations regarding the cases of the impact of genetically modified corn on the Monarch butterfly in the USA and the impact of herbicide-tolerant varieties of corn, beet and rapeseed on the populations of weeds as well as arthropods and birds feeding on them. Moreover, it underlines the necessity of conducting research based on correct methodologies and provides results of the first farm scale research conducted in Poland regarding the impact of MON 810 corn on the environment. Furthermore, it presents actions of the European Food Safety Authority (EFSA) encompassing: (a) building up mutual understanding of the rules forming the basis of risk assessment for new GMOs and (b) increasing transparency in current works among the EU Member States and EFSA and its committees. Setting up the EFSA Scientific Network is supposed to ensure that cooperation. Finally, the article summarizes the basics of GMO detection and control in the reference laboratories in Europe

Genetically modified plants - from the laboratory to practical use in European agriculture. Part I

Techniki biotechnologiczne umożliwiają hodowcy połączenie korzystnych cech z różnych organizmów. Roślina genetycznie zmodyfikowana zawiera gen lub geny, które zostały zmienione w wyniku działania człowieka metodami inżynierii genetycznej. Od 1996 r. obserwuje się stały wzrost areału upraw roślin zmodyfikowanych genetycznie na świecie, który w 2011 r. osiągnął powierzchnię 160 mln ha. Prawdopodobnie w przyszłości transgeniczność wielokrotna (ang. stacked events) będzie dominowała w nowych odmianach GM, łącząc cechy odporności na szkodniki, tolerancję na herbicydy i niekorzystne warunki środowiska, jak też cechy dotyczące składu związków roślinnych. W Unii Europejskiej i na świecie obowiązują uregulowania prawne kompleksowo obejmujące kwestie GMO. Unia Europejska ma jeden z bardziej restrykcyjnych systemów prawnych dotyczących GMO. Przepisy zapewniają ochronę środowiska, zdrowia zwierząt i człowieka oraz informację dla konsumenta. Wymagają też szczegółowego badania każdego GMO na poszczególnych etapach uzyskiwania zgody na użycie takich organizmów. Współistnienie różnych typów produkcji ma zapewnić rolnikom i konsumentom europejskim możliwość wyboru. Prawo UE stanowi podstawę dla uregulowań prawnych związanych z GMO, obowiązujących w Polsce.Biotechnological techniques enable the breeder to combine a number of favourable properties of different organisms. A genetically modified plant contains gene or genes that have been modified by humans using genetic engineering. Since 1996 a constant expansion of the area of genetically modified crops is observed throughout the world, reaching 160 million has. in 2011. It is likely that in the future stacked events will dominate in new GM varieties, combining properties such as resistance to pests and tolerance to herbicides and adverse environmental conditions, as well as various quality properties. The European Union and other countries have implemented comprehensive legal regulations on matters related to GMO. The EU has one of the more restrictive legal systems on GMO. Those regulations ensure the protection of the environment, human and animal health, and proper information for the consumer. The regulations also stipulate detailed analysis of each GMO at every stage of the process of approval for the use of such organisms. Coexistence of different types of crops is aimed at providing European farmers and consumers with choice options. The EU law is the basis for the legal regulations on GMO applicable in Poland

The Determination Of Diffusive Tortuosity In Concrete Specimens Using X-Ray Microtomography

The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens