HONEY BEES, APIS MELLIFERA (HYMENOPTERA: APIDAE), AS POLLINATORS OF LOWBUSH BLUEBERRY, VACCINIUM ANGUSTIFOLIUM, ON NEWFOUNDLAND COASTAL BARRENS

1983 ◽  
Vol 115 (12) ◽  
pp. 1647-1651 ◽  
Author(s):  
Derek Lomond ◽  
David J. Larson
Keyword(s):  
Honey Bees ◽  
Fruit Set ◽  
Test Field ◽  
Control Field ◽  
Lowbush Blueberry ◽  
Short Period ◽  
Native Pollinator ◽  
The Difference ◽  
Avalon Peninsula ◽  
Pollinator Populations

AbstractFlower production, fruit set, and pollinator activity were measured in two 1-year postburn blueberry fields on the coastal barrens of the Avalon Peninsula, Newfoundland. Honey bees were stocked at a density of 1.7 colonies/ha in one field while the control field lacked honey bees. Bloom production was similar in the two fields but fruit set was 54% in the test compared with 39% in the control field. Native pollinator (bee) populations were similar between fields but total pollinator populations were much higher in the test field with the difference contributed by honey bees. On the coastal barrens, where native pollinator populations are low and bloom exists in abundance for a short period of time, under-pollination may limit fruit set under some conditions and thus honey bees may have value in increasing fruit yield.

Grower perceptions of native pollinators and pollination strategies in the lowbush blueberry industry

2013 ◽  
Vol 30 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Samuel P. Hanes ◽  
Kourtney K. Collum ◽  
Aaron K. Hoshide ◽  
Eric Asare
Keyword(s):  
Honey Bees ◽  
Fruit Set ◽  
Social Science Research ◽  
Science Research ◽  
Vegetable Crops ◽  
Factors Affecting ◽  
Lowbush Blueberry ◽  
Northeast Us ◽  
Important Form ◽  
Security Study

AbstractPollinator declines and dependence on insect pollination, particularly in fruit and vegetable crops, creates a pressing need to understand growers' interactions with pollinators and factors affecting pollination strategies. At present, many growers are dependent on commercial honey bees (Apis mellifera), but diversified strategies may be necessary to secure adequate crop pollination in the future. As of yet, little social science research exists on pollination practices. This article presents the results of a survey of lowbush blueberry growers in Maine. The survey was part of a five-year pollination security study focusing on four fruit and vegetables crops in the Northeast US. The survey assesses grower perceptions of native pollinators' effectiveness and their perceptions of native pollinators' contribution to fruit set. Results indicate a widespread perception among growers of native pollinators' importance. While native pollinators are not effective enough to replace rented honey bees for three-quarters of the industry, they are broadly seen as an important form of insurance in poor weather when honey bees' effectiveness is reduced. The main obstacle to greater utilization of native pollinators found in this study was uncertainty over native pollinators' contribution to yield and the associated difficulty monitoring native pollinators' population size. Scientists and extension experts must work to reduce these obstacles before more widespread use of native pollinators will occur.

THE INFLUENCE OF HONEYBEE POLLINATION ON FRUIT SET OF THE LOWBUSH BLUEBERRY

1961 ◽  
Vol 41 (2) ◽  
pp. 332-335 ◽  
Author(s):  
G. W. Wood
Keyword(s):  
Fruit Set ◽  
Weather Conditions ◽  
Adverse Weather Conditions ◽  
Lowbush Blueberry ◽  
Short Period ◽  
Adverse Weather ◽  
Plant Stand

Inconsistent results were obtained when the fruit set was determined in blueberry fields with and without the service of honeybees. Adverse weather conditions curtailed pollinator activity and this was reflected in poor fruit set. The advantage of using honeybees was more evident in the season which had a short period of bloom. No significant increase in percentage fruit set was obtained when the number of colonies of honeybees per acre was increased. There was also no correlation between percentage fruit set and composition of plant stand.

Comparison of two asynchronous QCT methods

2020 ◽  
Vol 24 (4) ◽  
pp. 108-118
Author(s):  
A. V. Petraikin ◽  
A. K. Smorchkova ◽  
N. D. Kudryavtsev ◽  
K. A. Sergunova ◽  
Z. R. Artyukova ◽  
...  
Keyword(s):  
Bone Densitometry ◽  
Pearson Correlation ◽  
Calibration Data ◽  
Mineral Density ◽  
Quantitative Ct ◽  
Short Period ◽  
Potassium Hydrogen ◽  
Patients At Risk ◽  
Ray Density ◽  
The Difference

Rationale. Quantitative CT (QCT) bone densitometry with asynchronous calibration not require a phantom during the scan procedure. Based on calibration data it converts X-ray density in HU to bone mineral density (BMD). Given the large number of CT studies performed on patients at risk of osteoporosis, there is a need for a hands-on method capable of assessing BMD in a short period of time without tailored software or protocols.Goal. To develop a method for QCT bone densitometry using an PHK (PHantom Kalium), to compare the volume BMD measurements with the QCT data with asynchronous calibration provided by software from a reputable developer.Methods. The studies were performed at 64-slice CT unit with body scanning parameters. The BMD was measured using two techniques: 1) QCT with asynchronous calibration using software from a reputable developer; 2) QCT using a PHK phantom (QCT-PHK). For convert the HU to BMD values, we scanned the PHK phantom and calculate correction factor. Phantom contains “vertebrae” filled with potassium hydrogen phosphate in different concentrations. In both methods, the BMD values measured for LI–II, and sometimes for ThXII, LIII.Results. The study enrolled 65 subjects (11 male and 54 female patients); median age 69.0 years. A comparison of the vertebrae BMD measured by QCT and QCT-PHK revealed a significant linear Pearson correlation r = 0.977 (p < 0.05). The Bland–Altman analysis demonstrated a lack of relationship between the difference in measurements and the average BMD and a systematic BMD; bias of +4.50 mg/ml in QCT vs. QCT-PHK. Differences in the division into groups osteoporosis / osteopenia / norm according to the ACR criteria for the two methods were not significant.Conclusion. The developed asynchronous QCT-PHK method measure BMD comparable to the widely used QCT with asynchronous calibration. This method can be used for opportunistic screening for osteoporosis.

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

scholarly journals THE ELIMINATION OF IRON AND ITS DISTRIBUTION IN THE LIVER AND SPLEEN IN EXPERIMENTAL ANEMIA

1917 ◽  
Vol 25 (5) ◽  
pp. 675-691 ◽  
Author(s):  
Harry Dubin ◽  
Richard M. Pearce
Keyword(s):  
Sodium Oleate ◽  
Immune Serum ◽  
The Body ◽  
Bile Pigment ◽  
Striking Increase ◽  
Short Period ◽  
The Difference ◽  
Ultimate Fate ◽  
Cell Fragments ◽  
Severe Type

Blood destruction due to a single injury, as by sodium oleate, or acting through a short period of time, as by toluylenediamine or hemolytic immune serum, is not characterized, in the absence of hemoglobinuria, by an increased elimination of iron in the urine. This holds, not only for the evanescent injury caused by sodium oleate, but also for the severe type caused by hemolytic immune serum, in which a progressive destruction of the blood may persist for 2 weeks or more with constant evidence of the disintegration of erythrocytes as shown by bile pigment in the urine. This finding is in accord with previous investigations of anemia in both man and animals. Likewise, no striking increase is evident, under such circumstances, in the percentage of iron excreted in the feces. The total amount of iron in the feces has been notably increased in two experiments with hemolytic serum, but as the percentage was not appreciably altered, the difference depends presumably on variations in the bulk of feces rather than upon increased elimination. This evidence of the power of the body to conserve the iron rephagocytosis is negligible, is to be fragmented one by one, while still circulating, to a fine, hemoglobin-containing dust. The cell fragments are rapidly removed from the blood, but their ultimate fate remains to be determined. The facts indicate that they are removed from the blood by the spleen, and under exceptional conditions, by the bone marrow.

ALSIKE CLOVER POLLINATION BY HONEY BEES IN THE PEACE RIVER REGION

1959 ◽  
Vol 39 (4) ◽  
pp. 505-511 ◽  
Author(s):  
P. Pankiw ◽  
C. R. Elliott
Keyword(s):  
Honey Bee ◽  
Plant Species ◽  
Honey Bees ◽  
Climatic Conditions ◽  
Bumble Bees ◽  
Flowering Period ◽  
Peace River ◽  
River Region ◽  
Native Pollinator ◽  
Seed Yields

Pollination studies involving zero, one and three colonies of honey bees per acre, on commercial alsike clover fields ranging in size from 15 to 75 acres, were conducted in 1954, 1955, and 1957 in the Hinton Trail district of the Peace River Region of Alberta. These studies indicated that in large fields one colony of honey bees per acre is sufficient to pollinate alsike clover, consideration being given to competition of other crops and to the climatic conditions. The influence of competing crops was such that 65- to 75-acre fields, with one colony per acre, were similar in honey bee populations and seed production to 15- to 20-acre fields with three colonies per acre. Competing plant species accounted for 15 to 36 per cent of the pollen collected by honey bees. Fields with the higher populations of pollinators matured earlier than fields deficient in pollinators. A population of 3400 honey bees per acre (0.7 bee per sq. yd.) throughout the flowering period resulted in seed sets up to 82 per cent and seed yields to 375 lb. per acre. Check fields, where no honey bees were supplied, ranged in production from 29 lb. per acre, with a low native pollinator count, to 293 lb. where a pollinator equivalent of 1300 bumble bees per acre was observed. Bumble bees worked alsike clover at the rate of 28.6 florets per minute, as compared to 20.0 for leaf-cutter bees and 18.7 for honey bees.

scholarly journals Case AD, AR, and AS binary evolution and their possible connections with W UMa binaries

2019 ◽  
Vol 492 (2) ◽  
pp. 2731-2738 ◽  
Author(s):  
Dengkai Jiang
Keyword(s):  
Parameter Spaces ◽  
Short Period ◽  
Contact Binaries ◽  
Low Mass ◽  
Orbital Periods ◽  
The Difference ◽  
Binary Evolution ◽  
Detached Binaries ◽  
Period Limit ◽  
The Moment

ABSTRACT Close detached binaries were theoretically predicted to evolve into contact by three subtypes of case A binary evolution, cases AD, AR, and AS, which correspond to the formation of contact during dynamic-, thermal-, and nuclear-time-scale mass transfer phases, respectively. It is unclear, however, what is the difference between contact binaries in these subtypes, and whether all of these subtypes can account for the formation of observed W Ursae Majoris (W UMa) binaries. Using Eggleton’s stellar evolution code with the non-conservative assumption, I obtained the low-mass contact binaries produced by cases AD, AR, and AS at the moment of contact and their parameter spaces. The results support that the progenitors of low-mass contact binaries are detached binaries with orbital periods shorter than $\sim 2\!-\!5\,$ d, and their borderlines depend strongly on the primary mass. In addition, the period–colour relations for cases AR and AS can be in better agreement with that for observed W UMa candidates, but case AD shows a significantly worse agreement. Moreover, cases AR and AS can produce a short-period limit (corresponding to a low-mass limit) at almost any age, e.g. from young age ($\sim 0.2\,$ Gyr) to old age ($\sim 13\,$ Gyr), agreeing with observed W UMa binaries in star clusters, but no such limit occurs for case AD at any age. These results support that cases AR and AS, as opposed to case AD, can lead to W UMa binaries (including young W UMa binaries).

Spring frost damage to placental tissues in lowbush blueberry flower buds

2001 ◽  
Vol 81 (4) ◽  
pp. 779-781 ◽  
Author(s):  
A. Randall ◽  
Olson and Leonard J. Eaton
Keyword(s):  
Key Words ◽  
Fruit Set ◽  
Frost Damage ◽  
Full Bloom ◽  
Flower Buds ◽  
Vaccinium Angustifolium ◽  
Spring Frost ◽  
Lowbush Blueberry ◽  
Commercial Yield ◽  
Spring Frosts

Closed flower buds and flowers at full bloom of Vaccinium angustifolium Ait. were collected from the field and histologically examined after severe spring frosts. Prior to anthesis, blackened ovarian placentae in closed buds were the only damaged tissues evident; placental damage may interfere with both seed and fruit set. Undetected frost damaged placentae may contribute to losses in commercial yield. Key words: Vaccinium, frost damage, placenta

Pollinator Insects and their Impact on Crop Yield of Mustard in Kusma, Parbat, Nepal

2019 ◽  
Vol 24 (2) ◽  
pp. 68-75
Author(s):  
Narayan Subedi ◽  
Indra Prasad Subedi
Keyword(s):  
Crop Yield ◽  
Fruit Set ◽  
Apis Cerana ◽  
Qualitative And Quantitative ◽  
Significant Difference ◽  
The Difference ◽  
Four Blocks ◽  
And Control ◽  
The Impact ◽  
Pod Length

The diversity of insect pollinators and their impact on crop yield of mustard were studied in Kusma, Parbat, Nepal from December 2018 to April 2019 in four blocks with each having 12 m2 areas. Two plots; treatment and control, were established in each block. Insect diversity was observed from 8 to 16 hrs, with the interval of an hour for three consecutive months (Jan-Feb). Eighty mustard plants were randomly selected, 40 from each plot just before flowering to find the impact of insect pollination on crop yield and these selected plants were examined for various qualitative and quantitative parameters. Altogether 16 species of pollinator insects belonging to five orders and nine families were recorded. Hymenoptera (36 %) was the most abundant order visiting mustard flowers followed by Diptera (34 %), Coleoptera (17 %), Lepidoptera (12 %) and Heteroptera (1 %). The most abundant family was Apidae (35.64 %), followed by Syrphidae (31.84 %). Apis cerana and Eristalis sp. were the most important pollinator insects of mustard. Seven species were found foraging both on pollen and nectar, four species foraging only on nectar and remaining five as casual visitors. The peak foraging activities of majority of the insects were observed between 12 hr to 14 hr. A significant difference was observed in the number of pods (59.80 ± 1.967 and 70.47 ± 2.431), fruit set (70.55 ± 1.362 and 80.94 ± 0.638), number of seeds per pods (16.70 ± 0.248 and 19.30 ± 0.330), diameter of seed (0.133 ± 0.2547 and 0.275 ± 0.0051) and weight of 100 dry seeds (0.33 ± 0.058 and 0.48 ± 0.023) in control and treatment plots whereas, the difference was non-significant in case of pod length between control and treatment plots (P=0.163).

Constellation design for responsive visiting based on ground track adjustment

2017 ◽  
Vol 232 (12) ◽  
pp. 2300-2316
Author(s):  
Xiang Yu ◽  
Kun Liu ◽  
Qifeng Chen
Keyword(s):  
Search Algorithm ◽  
Design Methods ◽  
Pattern Search ◽  
User Requirements ◽  
Ground Track ◽  
Constellation Design ◽  
Short Period ◽  
The Difference ◽  
Orbit Period ◽  
Global Reach

Many responsive civilian or military space missions require that a certain ground site of interest be visited in a fairly short period (e.g., 12 h or less). To this end, a constellation must be utilized, since a single satellite is usually unable to fulfill such a task if the ground site is selected on the whole terrestrial surface responding to random user requirements. In this paper, the design approaches of such a constellation for responsive visiting based on ground track adjustment are investigated. By using the difference in orbit period between the maneuvered satellite and the reference satellite to make the ground track shift, reachable domain belts are generated. In terms of orbit maneuvering, two- and one-impulse maneuvers are analyzed and compared. Based on the reachable domain belts of a single satellite, two constellation design methods are proposed. The first one is an analytical method which is presented to achieve global reach and implemented by uniformly splicing together the widest belts of all satellites within the range of [0°, 180°]. The second one is an optimized method proposed to further reduce the number of satellites, by splicing together all the reachable domain belts rather than only the widest belts in the equator. A hybrid algorithm that consists of the genetic algorithm and the pattern search algorithm is proposed to minimize the number of satellites. Numerical examples are provided to illustrate the two proposed constellation design methods and validate the global reach performance.

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