Case-control study to detect protective factors on pig farms with low Salmonella prevalence

The prevalence of Salmonella in UK pigs is amongst the highest in Europe, highlighting the risk to public health and the need to investigate on-farm controls. The objective of this study was to identify factors currently in operation on pig farms that had maintained a low Salmonella seroprevalence. For this purpose a case-control study was designed and pig farms with a low (\u3c10%) seroprevalence were compared against two randomly selected control farms, sharing the same geographical region and production type. A total of 11,452 samples, including pooled and individual floor faeces and environmental samples from pigs and their vicinity were tested and prevalence examined. In addition, detailed questionnaires were completed during the farm visits to collect descriptive data for risk factor analysis. It was shown that control farms had significantly higher prevalence compared to the case farms (19.4% and 4.3% for pooled and 6.7% and 0.1% for individual samples, respectively). The two risk factor analyses identified multiple variables associated with Salmonella prevalence including variables related to feed, effectiveness of cleaning and disinfection, biosecurity and batch production

Description of selected landslides from southern Poland activated after intensive rainfall in 2010

W artykule przedstawiono wyniki badań, które przeprowadzono na 74 osuwiskach z terenu południowej Polski, które powstały lub uaktywniły się po okresie intensywnych opadów w 2010 roku. W większości były to osuwiska, które spowodowały znaczne straty w budynkach mieszkalnych i infrastrukturze i których dalszy rozwój, w przypadku braku odpowiednich przeciwdziałań, może być źródłem poważnych problemów dla gospodarki. Prace obejmowały m.in. pomiar parametrów geometrycznych osuwiska (długość, szerokość, kąt nachylenia niszy oraz stoku, wysokość zerwy itp.), ocenę warunków geomorfologicznych i geologicznych, ustalenie rodzaju występujących gruntów i sposobu ich zalegania, typu osuwiska, występowania wód powierzchniowych i podziemnych, ekspozycji zbocza. Uwagę zwrócono również na geologiczno-inżynierskie warunki powstania osuwisk, powstałe szkody i zagrożenia oraz wykonane prace zabezpieczające. Wyniki badań wykazały, iż analizowane osuwiska to w większości obszary o powierzchni przekraczającej 1 tys. m2 i kącie nachylenia stoku ponad 20°. W 52% przypadków stwierdzono wpływ czynników antropogenicznych. Były to głównie: dodatkowe obciążenie skarp nasypem lub obiektem budowlanym, podcięcie zbocza przez wykop drogowy oraz błędy w projektowaniu. Naturalne przyczyny związane są natomiast głównie z oddziaływaniem wód opadowych w postaci zmian stanów wód powierzchniowych i podziemnych.The article presents the results of the research which was carried out on 74 landslides in southern Poland. The landslides generated or reactivated after a rainfall in 2010. Most landslides caused signifi cant losses in residential buildings and infrastructure, which in case of further development and no appropriate countermeasures, may cause serious problems for the economy. The investigations on each landslide included: measurements of geometric parameters (length, width, angle of inclination of the slope and the niche, etc.), assessment of geomorphological and geological conditions, determination of the soil type, the arragement of soil layers, the type of the landslide, the presence of surface water and groundwater, and slope exposure. An attention was paid also to the engineering-geological conditions of landslides formation, damages caused by the mass movement and threats. The protection works were also described. The results showed that most of analyzed landslides has an area exceeding one thousand m2 and the angle of inclination over 20°. In 52% of cases the impact of anthropogenic factors was noticed. These were mainly: additional loading of slope by an embankment or other construction, undercutting by road excavation and errors in design. Natural causes are mainly associated with the impact of the rainwater, which has caused changes in surface water and groundwater conditions

Charakterystyka wybranych osuwisk z terenu Polski południowej uaktywnionych po okresie intensywnych opadów w 2010 r.

W artykule przedstawiono wyniki badań przeprowadzonych na 74 osuwiskach z terenu Polski południowej, które powstały lub uaktywniły się po okresie intensywnych opadów w 2010 r. W większości spowodowały one znaczne straty w budynkach mieszkalnych i infrastrukturze. Bez podjęcia działań zaradczych mogą być źródłem poważnych problemów gospodarczych

Effects of temperature on the development of Thrips nigropilosus Uzel (Thysanoptera: Thripidae) on Mentha x piperita L. and the impact of pest on the host plant

Thrips nigropilosus Uzel is a polyphagous species occurring mainly in temperate climates. Its life cycle depends on photoperiodic and temperature conditions. T. nigropilosus feeds on different plant species, but it is considered one of the most serious pests of pyrethrum plants causing serious economic problems. However, several additional agricultural host plants have been affected by T. nigropilosus, including spearmint, cucumber, and lettuce, indicating that this insect can significantly widen its habitats and occurs especially frequently in greenhouses. We report that T. nigropilosus massively attacked Mentha × piperita L. cultivated in greenhouses in central Poland and destroyed the entire mint crops within a short time. The study provided insight into the harmful effect of the thrips and showed that the length of the thrips developmental cycle was reduced with temperature increases from 18 to 26.6°C. The lower threshold temperatures were 13.7, 10.2, 5.0, and 10.1 for eggs, larvae, pupae, and total development, respectively, and the thermal constant for the same developmental stages was 65.9, 90, 132.5, and 284.9-degree days. Both parameters were estimated by linear regression analysis. During our experiment, T. nigropilosus developed by thelytokous parthenogenesis. The morphological and anatomical changes in damaged plants were associated with the fact that the insect began feeding on the lower lamina surface close to the leaf midribs, but no damage to vascular bundles and glandular cells was observed