Search results for "bee"

A new automated single ring infiltrometer for Beerkan infiltration experiments

2014

A new automated compact device was developed to collect data from single ring infiltration experiment. The infiltrometer consists of a containment ring in which a small quasi-constant head of water (i.e. a few mm) is maintained by a Mariotte reservoir and a very inexpensive data acquisition system, based on the open source microcontroller platform Arduino, and a differential pressure transducer. The design can easily be reproduced and operated. The infiltrometer was tested in a citrus orchard on a sandy loam soil. A simple methodology was applied for an accurate data acquisition from the initial stage of the process and to minimize the disturbance of the soil surface. A new approach to proc…

Evaluation of yeasts from Ecuadorian chicha by their performance as starters for alcoholic fermentations in the food industry

2020

Yeasts involved in the spontaneous fermentation of traditional beverages like chicha (indigenous Andean beer) may have the potential to be used as starter cultures to improve the quality and microbiological safety of these products, but also as non-conventional alternatives to other food alcoholic fermentations. In this research, we isolated, identified and characterised yeast strains from four Ecuadorian chichas made by using four different raw materials: rice (RC), oat (OC), grape (GC) and a mixture of seven corn varieties (yamor, YC). Finally, 254 yeast isolates were obtained and identified by molecular methods. Eleven yeast genera and 16 yeast species were identified with relatively few…

A cost of maternal care in the dung beetle Onthophagus taurus?

2002

Parental care theory assumes that investment in current offspring will trade against future investment. A number of field studies on birds have used clutch size manipulations to demonstrate a survival cost to chick rearing. However, such studies do not account for costs accrued during earlier stages of reproduction because not all aspects of reproductive effort are manipulated by varying the number of nestlings. In this study, we investigate the effect of reproductive effort on female survival in the dung beetle, Onthophagus taurus. By experimentally manipulating mating status and dung availability, we demonstrate that virgin females survive longer than mated females and that the survival o…

Testing a Simplified Approach to Determine Field Saturated Soil Hydraulic Conductivity

2013

Abstract Interpreting and simulating hydrological processes need a large number of field saturated soil hydraulic conductivity, Kfs , data that should be collected with simple and rapid field experiments. A Simplified method based on a Beerkan Infiltration run (SBI method) was recently developed and tested successfully on Burundian soils. With the SBI method, a cylinder is inserted to a short depth into the soil and the infiltration time of a few small volumes of water repeatedly applied at the surface of the confined soil is measured. Calculating Kfs needs the slope of the linearized cumulative infiltration vs. time relationship and an estimate of the so called α* parameter. In this invest…

Host-range expansion of Spodoptera exigua multiple nucleopolyhedrovirus to Agrotis segetum larvae when the midgut is bypassed.

2010

Given the high similarity in genome content and organization between Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and Agrotis segetum nucleopolyhedrovirus (AgseNPV), as well as the high percentages of similarity found between their 30 core genes, the specificity of these NPVs was analysed for the respective insect hosts, S. exigua and A. segetum. The LD(50) for AgseNPV in second-instar A. segetum larvae was 83 occlusion bodies per larva and the LT(50) was 8.1 days. AgseNPV was orally infectious for S. exigua, but the LD(50) was 10 000-fold higher than for SeMNPV. SeMNPV was not infectious for A. segetum larvae when administered orally, but an infection was established by injecti…

Women’s empowerment and child mortality: the case of Bangladesh

2018

Effects of forest restoration treatments on the abundance of bark beetles in Norway spruce forests of southern Finland

2009

Abstract Restoration of protected areas in boreal forests frequently includes creating substantial volumes of dead wood. While this benefits a wide range of dead wood dependent invertebrate species, some of these are regarded as forest pests. Therefore, the risk of elevated levels of tree mortality in surrounding commercial forests must be considered. In a large-scale field experiment in southern Finland, we studied the effects of restoration treatments on the abundance of bark beetles within and in the vicinity of restored areas, in particular focusing on Ips typographus and Pityogenes chalcographus . The treatments applied to managed Norway spruce forests were controlled burning and parti…

Experimental observations of upstream overdeepening

2005

The issue of morphodynamic influence in meandering streams is investigated through a series of laboratory experiments on curved and straight flumes. Both qualitative and quantitative observations confirm the suitability of the recent theoretical developments (Zolezzi & Seminara 2001) that indicate the occurrence of two distinct regimes of morphodynamic influence, depending on the value of the width ratio of the channel β. The threshold value βR separating the upstream from the downstream influence regimes coincides with the resonant value discovered by Blondeaux & Seminara (1985). Indeed it is observed that upstream influence may occur only in relatively wide channels, while narrower stream…

Diachronic Analysis of Beech Forest in the Nebrodi Park (Northern Sicily)

2017

A comparison between the current surface of Beech forest in the Nebrodi Park (Northern Sicily) with the measurements performed in the past is here reported. 12.854 hectares of Beech forest were recognized against 10.336 hectares of 1959 with a percentage increase of 24.37%. The increase of forest is mainly due at the change of land use through a better forest management and grazing.

Syntaxonomical analysis of the beech forests from Sicily

1999

The results of a phytosociological investigation on the beech forests occurring in Sicily are given. On the basis of literature and unpublished data, four well differentiated associations have been identified and classified within the Doronico-Fagion, alliance of Querco-Fagetea. All the surveyed woodlands are localized in the mountain belt of North and North-Eastern Sicily. The associations have been examined from the floristical, ecological, chorological and nomenclatural point of view. Besides, a numerical analysis applied to the phytosociological relevés emphasizes the differences among the associations.