The queen is led? Bumblebee (Bombus spp.) nest-searching on sea wall banks may be influenced by cutting and sward height

2019 ◽  
Vol 70 (4) ◽  
pp. 249-257
Author(s):  
Kimberley Fargeaud ◽  
Tim Gardiner
Keyword(s):  
Soil Type ◽  
Tall Grass ◽  
Searching Behaviour ◽  
Sward Height ◽  
Mowing Regime ◽  
Under Construction ◽  
Sea Wall ◽  
Nest Searching ◽  
Previous Summer

English sea wall flood defences support an important grassland habitat for bumblebees (Bombus spp.). However, annual cutting in midsummer (July–August) could negatively affect them. The mowing regime on a sea wall at Goldhanger Creek in Essex was changed to a late cut (after 15 September) and nest-searching behaviour was compared with an adjacent sea wall cut in midsummer (normal cut in August). Sward height and the number of queens nest-searching were significantly higher on the normal cut sea wall than on the late cut one. Tall grass swards resulting from a cut early in the previous summer may be important for nest-searching compared to those mown late, although there is probably an interaction with sea wall aspect and soil type. The landward slope was also more attractive for nesting than the flat folding (berm) due to the longer vegetation where nests under construction were located (of Bombus humilis and B. terrestris).

Selective grazing by dairy cows in the presence of dung and the defoliation of tall grass dung patches

1998 ◽  
Vol 66 (1) ◽  
pp. 65-73 ◽  
Author(s):  
J. Bao ◽  
P. S. Giller ◽  
G. Stakelum
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Tall Grass ◽  
Late Season ◽  
Average Area ◽  
Sward Height ◽  
Selective Grazing ◽  
Biting Rate ◽  
Relative Utilization ◽  
Grazing Behaviour

AbstractTwo studies investigated the effect of contaminated pasture on selective grazing, overall grazing behaviour and the process of defoliation of dung patches through experiments targeted at four major questions: (a) how does relative utilization of tall and short grass change as the sward is grazed down? (b) what effect does herbage mass and sward height have on the relative utilization of short and tall grass? (c) how are tall grass patches actually utilized by cattle? and (d) how is overall grazing behaviour influenced by contamination of the sward?Experiments were conducted in mid to late season using Friesian dairy cattle. In experiment 1, two -pasture types (topped sward (T) v. grazed-only sward (G)) were used. The distribution of bites on tall grass from both pasture types indicated that the grazing animals tended initially to graze short grass when they met a new sward, and then select tall grass as the swards were progressively grazed down. This switch happened earlier in the defoliation process in the topped sward. In experiment 2 observations were conducted on previously grazed and previously ungrazed swards. The distribution of bites on tall grass showed a similar trend to that found in experiment 1 and as the sward was gradually grazed, biting rate significantly declined. There was also a significantly higher total grazing time on the previously ungrazed sward (no contamination by dung). Comparing data based on a consistent biting rate (calculated as the time for 20 consistent bites) and natural biting rate (calculated as the total time for 20 bites) suggested that the grazing animals had increased difficulty in handling tall grass which may explain the declining biting rate as the swards were being grazed down and more bites were directed at tall grass. The defoliation of tall grass dung patches appeared to be concentrated around the edges of the patch. The average area of sward affected by a single dung pat was 1·04 m2 measured at the pre-grazing stage and was markedly reduced to 0·51 m2 at the post-grazing stage. In conclusion, selective grazing is likely to exist due to the presence of dung and conditioned by dung distribution and sward type and this in turn modifies biting rate during grazing down of a sward.

Quinclorac and Aminocyclopyrachlor Movement in Sandy Soils

2015 ◽  
Vol 8 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Jason W. Adams ◽  
Rodney G. Lym
Keyword(s):  
Soil Type ◽  
Shallow Groundwater ◽  
Sandy Soils ◽  
Leafy Spurge ◽  
Soil Types ◽  
Heavy Rainfall Event ◽  
Tall Grass ◽  
Ecological Sites ◽  
Platanthera Praeclara ◽  
Simulated Field

AbstractThe Sheyenne National Grassland (SNG) is a native tall grass and mixed grass prairie located in southeastern North Dakota. Approximately half of the SNG has been invaded by leafy spurge (Euphorbia esulaL.) and control methods have been limited. Many herbicides cannot be utilized at the SNG due to sandy soils (> 80%) and shallow groundwater, nor can they be applied near the western prairie fringed orchid (Platanthera praeclaraSheviak and Bowles), a federally listed threatened plant found on the SNG. Quinclorac and aminocyclopyrachlor were considered for use on the SNG but potential to enter the groundwater was unclear. Movement of quinclorac and aminocyclopyrachlor was evaluated in 70 cm soil columns that simulated field conditions from five ecological sites. Quinclorac leached further following the heavy rainfall event of 15 cm in 48 h compared to the annual precipitation of 51 cm applied over 9 wk. Quinclorac leached approximately 45 cm into the soil profile averaged over all soil types and both precipitation events but never exceeded 65 cm regardless of soil type. Aminocyclopyrachlor leaching was greater than quinclorac and moved through all soil types into the leachate following both watering regimes. Desorption of both herbicides was incomplete. Approximately 10 and 32% of applied aminocyclopyrachlor and quinclorac, respectively, remained in the top 5 cm of soil regardless of soil type or watering regime. Quinclorac but not aminocyclopyrachlor was considered suitable for use at the SNG to control leafy spurge and has the added benefit of not harming the western prairie fringed orchid.

A Magnetic Spectrometer for a Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 436-437
Author(s):  
A. Kosiara ◽  
J. W. Wiggins ◽  
M. Beer
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Magnetic Spectrometer ◽  
Fringe Field ◽  
Curvature Radius ◽  
Magnetic Pole ◽  
Quadrupole Field ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Under Construction ◽  
Image Position

A magnetic spectrometer to be attached to the Johns Hopkins S. T. E. M. is under construction. Its main purpose will be to investigate electron interactions with biological molecules in the energy range of 40 KeV to 100 KeV. The spectrometer is of the type described by Kerwin and by Crewe Its magnetic pole boundary is given by the equationwhere R is the electron curvature radius. In our case, R = 15 cm. The electron beam will be deflected by an angle of 90°. The distance between the electron source and the pole boundary will be 30 cm. A linear fringe field will be generated by a quadrupole field arrangement. This is accomplished by a grounded mirror plate and a 45° taper of the magnetic pole.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

Description of a New High Resolution Scanning Transmission EM

1972 ◽  
Vol 30 ◽  
pp. 418-419
Author(s):  
Michael Beer ◽  
J. W. Wiggins ◽  
David Woodruff ◽  
Jon Zubin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Objective Lens ◽  
Condenser Lens ◽  
Transmission Electron ◽  
Pattern Size ◽  
Scanning Transmission ◽  
Under Construction

A high resolution scanning transmission electron microscope of the type developed by A. V. Crewe is under construction in this laboratory. The basic design is completed and construction is under way with completion expected by the end of this year.The optical column of the microscope will consist of a field emission electron source, an accelerating lens, condenser lens, objective lens, diffraction lens, an energy dispersive spectrometer, and three electron detectors. For any accelerating voltage the condenser lens function to provide a parallel beam at the entrance of the objective lens. The diffraction lens is weak and its current will be controlled by the objective lens current to give an electron diffraction pattern size which is independent of small changes in the objective lens current made to achieve focus at the specimen. The objective lens demagnifies the image of the field emission source so that its Gaussian size is small compared to the aberration limit.

Cochlea Under Construction

ASHA Leader ◽  
2011 ◽  
Vol 16 (9) ◽  
pp. 40-41
Author(s):  
Jessica J. Messersmith
Keyword(s):  
Under Construction

Effect of climatic conditions and soil type on antioxidant compounds in organic and conventional blueberries (Vaccinium corymbosum L.)

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
MD López ◽  
P Jara ◽  
S Fischer ◽  
R Wilckens ◽  
H Serri ◽  
...  
Keyword(s):  
Soil Type ◽  
Vaccinium Corymbosum ◽  
Climatic Conditions ◽  
Antioxidant Compounds

‘The well-known, old, but still unbeaten track’: Women Poets and Irish Periodical Culture in the Mid-Twentieth Century

2012 ◽  
Vol 42 (1) ◽  
pp. 32-52 ◽  
Author(s):  
Anne Mulhall
Keyword(s):  
Twentieth Century ◽  
Literary Culture ◽  
Woman Writer ◽  
Double Bind ◽  
Women Poets ◽  
Substantial Body ◽  
Growing Body ◽  
Critical Attention ◽  
Irish Women ◽  
Under Construction

While neglected Irish male poets of the mid century have seen some recuperation in recent decades, the work of Irish women poets still languishes in obscurity. A growing body of scholarship has identified the need to bring critical attention to bear on this substantial body of work. In this essay I explore the positioning of Irish women poets in mid-century periodical culture, to flesh out the ways in which the terms of this ‘forgetting’ are already established within the overwhelmingly masculinist homosocial suppositions and idioms that characterized contemporary debates about the proper lineage and aesthetic norms for the national literary culture that was then under construction. Within the terms set by those debates, the woman writer was caught in the double bind that afflicted any woman wishing to engage in a public, politicized forum in post-revolutionary Ireland. While women poets engage in sporadic or oblique terms with such literary and cultural debates, more often their voices are absent from these dominant discourses – the logic of this absence has continued in the occlusion of these women poets from the national poetic canon.

Sign in / Sign up

Export Citation Format

Share Document