Sentences with phrase «many safe sites»

Various dorm rooms at Boston College in Chestnut Hill, Massachusetts, have a «Safe Site» symbol on their door.

I love that it is an easy directory for my 7 year old to find safe sites on the internet.

In June 1947, Windscale on the Cumbrian coast was named as a safe site for the production of plutonium.

The risk of overdose or arrest does not stop addicts, so providing safe sites staffed by naloxone - equipped medics does not encourage them.

Safe sites also work best in places where drug use is centralized, such as in specific urban neighborhoods rather than rural areas.

That way, the safest sites for each cache of emergency equipment can be established.

To be on the safe site — ungroomed spots on the bee's body and their importance for pollination.

These findings suggest that these «safe sites» for pollen on bees» bodies play an important role in pollination.

The area of each of the safe sites (areas with residual pollen) on the animals» body as well as the area of the whole insect body (exoskeleton including projecting bristles of caput = head, thorax and abdomen) was measured from the photos with the image processing software Fiji [44], calculating from the scale paper.

The identification of safe sites is restricted to the description of patches of pollen grains remaining after the bees» grooming behaviour following pollen deposition by pollen - sacs during flower visits.

Also in Borago officinalis the pigment was transferred from the stigma into the safe sites of the head and the ventral abdomen of A. mellifera, whereas pollen was deposited allover the ventral side (Fig 4G — 4I).

Contrary, the pollen accumulations within the safe sites were more clearly visible because of strong autofluorescence.

In the safe sites, in all cases, the area contaminated with luminous pigment from the pollen - sacs overlapped with that contaminated with pigment from the stigmas.

The amount of pollen grains was significantly larger in the safe sites of B. terrestris (11208 ± 5779) than in those of A. mellifera (6240 ± 3135)(Mann - Whitney U-test: p < 0.007, Z = -2.74).

Moreover, the importance of safe sites could be evaluated by measuring the proportion of safe site pollen delivered onto a conspecific stigma of one or more flowers as compared to the amount of pollen from outside the safe sites.

Additionally, as bees and bumble bees are said to usually groom during flight between flowers [16,41], it should be examined whether grooming behaviour — and thus pollen distribution in safe sites — differs when bees groom during flight as our study is mainly limited to grooming during perching.

Future research will demonstrate the importance of safe sites for plant pollination under field conditions.

There was no significant difference between the number of pollen grains of the head and thorax safe sites (caput: p > 0.2, Z = -1.1, thorax: p > 0.4, Z = -0.9)(Fig 2B, S2 Table).

This could either be caused by less effective or shorter grooming behaviour in B. terrestris, or, alternatively by the different accessibility of the relevant safe sites due to differences in the hairiness and mobility of legs and body.

In this way, the pollen (or most of it) might be deposited on spots of the bees» body, so - called «safe sites», where the bees can not see, taste or feel it, or where they are less capable to groom it off, [10,26 — 29].

The larger the congruence between the area contaminated with pollen by the pollen - sacs or that has been contacted by the stigma and the respective safe site of the corresponding pollinator, the lower is the probability of losing pollen according to the bees» grooming activity.

With the combination of experimental contamination of bees with pollen and subsequent grooming by the bees we have been able to precisely characterise safe sites on the bees» body.

The safe sites comprised 24.5 % of the dorsal projection of the body in B. terrestris (caput: 13.4 %, thorax: 20.8 %, abdomen: 30.2 %) and 23.5 % in A. mellifera (caput: 9.7 %, thorax: 41.0 %, abdomen: 21.1 %)(S1 Table).

Thus, the study of safe sites on the bees» bodies and the pollen grains» ride in space and time and their role in pollination still remains a challenge.

Some of the safe sites in B. terrestris and A. mellifera only slightly differ in shape or size.

To our knowledge, there is no published experimental evidence for safe sites on bees.

B. terrestris: overall view with arrow - shaped safe site on the thorax (A), safe site above the insertion of antennae on the head (B), dorsal thorax (triangular)(C, D), waist (E), abdomen (F, G), and ventral abdomen (H), A. mellifera: overall view with broad safe site on the thorax and narrow safe site on the abdomen (I), safe site between the eyes (J), dorsal thorax (K), waist (L), and abdomen (M), as well as ventral abdomen (N), dorsal thorax and abdominal safe site under full spectrum illumination (O) and UV - illumination (P).

Only those safe sites were measured whose outlines where clearly visible.

The dynamics of pollen turnover in safe sites due to subsequent flower visits, causing both pollen export to stigmata and pollen import onto the bees» body [29,60], might affect the outcrossing distance [28, 61].

46 % of the head safe site area in B. terrestris is covered by pigment from S. officinalis pollen - sacs and 37 % with pigment from stigmas.

The number of pollen grains left in the safe sites significantly differed within the bee species (ANOVA, B. terrestris: F = 13.96, p < 0.0001; A. mellifera: F = 12.16, p < 0.0001).

In order to determine the safe sites on the insects» body, the following procedure was carried out in the laboratory.

For the first time, we experimentally demonstrated the position, area and pollen amount of safe sites at the examples of Apis mellifera and Bombus terrestris by combining artificial contamination of the bees» body with pine or sunflower pollen and the subsequent bees» incomplete grooming.

It has been hypothesised that specific body areas, bees can not groom, serve as «safe sites» for pollen transfer between flowers.

The grooming behaviour and the resulting position of the safe sites on B. terrestris and A. mellifera were very similar and also independently from the pollen type (Pinus, Sunflower).

These patches are restricted to the spots being dusted with pollen by the flowers of the specific species and do not necessarily include all possible safe sites.

The ability of flowers to manoeuvre the bees into specific positions on the flower for precise pollen transfer might play a key role for the precision of pollen transfer within safe sites.

In S. pratensis, 20 % of the safe site area on the bumblebees» thorax was contaminated by the pollen - sacs and 9 % by the stigmas.

Additionally, the shape, stiffness and position of the style and stigma could determine whether outer (distal) pollen, probably deposited recently, or pollen from lower (proximal) layers, probably deposited earlier, of the safe sites gets transferred [29,62].

In order to investigate whether plants use the bees» safe sites to ensure pollen transfer, the following experiments were carried out in an indoor flight cage at the example of Salvia pratensis L. and Salvia officinalis L. with laboratory B. terrestris as well as with Borago officinalis L. (Boraginaceae) and managed A. mellifera caught in the Botanical Garden (HHU Düsseldorf).

The safe sites of A. mellifera identified in our study are similar to those on the dorsal and ventral midline of honeybees pollinating different Pedicularis L. species (Orobanchaceae) in China [38](S6 Table), indicating the safe sites» relevance in a natural context.

The area of each safe site on the animals» body was measured from the photos with the image processing software Fiji [44], calculating from the scale paper.

With the complex staminal lever mechanism of thespecialised bee - flowers S. pratensis and S. officinalis, pollen would be deposited rather precisely onto the safe sites of B. terrestris.

Similar safe sites have been observed on Xylocopa sp. (dorsal thorax)[26], Megachile ericetorum (dorsal thorax)[48] and Euglossa imperialis (anterior face and between thorax and abdomen)[42](S6 Table).

The concept of safe sites for pollen transfer on bees» bodies does not put the major role of bees as pollinators into question, but might focus future research to guidance of bees on flowers to take favorable positions for safe pollen transport by means of floral filtering of suitable pollinators [26], morphological match between pollinators and flowers [54] and floral guides [55] as well as potential strategies of flower visitors to bypass the flowers» restrictions (e.g. bees with specialised hairs for pollen collection from specialised bee - flowers)[26] or strategies of plants via shifting to non-pollen collecting pollinators (e.g. birds)[56 — 57,64 — 66].

The discrepancies between these areas and the safe sites found in our study might be due to different grooming behaviour / capabilities in the different bee species.

To confirm the safe sites found, the autofluorescence of sunflower pollen was used.

The average safe site contained all areas formed by overlapping of at least five animals.

Dorsal safe site areas (A) and amount of pollen grains in safe sites (B) of Bombus terrestris and Apis mellifera.

The pollen amount of the dorsal waist, dorsal abdomen and ventral safe site was significantly larger in B. terrestris than in A. mellifera (waist: p < 0.03, Z = -2.3, dorsal abdomen: p < 0.0001, Z = -4.1, ventral abdomen: p < 0.002, Z = -3.1).