Minimum size threshold of visiting bees of a buzz‐pollinated plant species: consequences for pollination efficiency

The use of growth curves to assess the crowding effect on procercoids of the tapeworm Triaenophorus crassus in the copepod host Cyclops bicuspidatus thomasi

Canadian Journal of Zoology ◽

10.1139/z85-347 ◽

1985 ◽

Vol 63 (10) ◽

pp. 2343-2351 ◽

Cited By ~ 10

Author(s):

Allen W. Shostak ◽

Ronald B. Rosen ◽

Terry A. Dick

Keyword(s):

Growth Rates ◽

Natural Variation ◽

Growth Curves ◽

Fixed Time ◽

Minimum Size ◽

Crowding Effect ◽

Average Volume ◽

Growth Initiation ◽

Accelerated Growth ◽

Size Threshold

Richards growth curves were fitted to data from procercoids of Triaenophorus crassus (Pseudophyllidea) in experimentally infected Cyclops bicuspidatus thomasi (Copepoda). Average volume per procercoid varied inversely with intensity, and procercoids in female copepods were correspondingly larger than procercoids in males. The simple inverse relationship, which usually characterizes the crowding effect on cestode size, held for average procercoid growth rates, but the growth rates of differentiated and undifferentiated procercoids diverged at higher intensities. Three apparently intrinsic features of procercoid growth (initiation of differentiation at a fixed time, a minimum size threshold for differentiation, and an accelerated growth rate in procercoids following differentiation) provided a mechanism whereby natural variation in procercoid growth rates could be amplified to produce a parasite infrapopulation comprising large, differentiated procercoids and stunted, undifferentiated procercoids. Calculations using parameters of the fitted growth curves indicated that the hosts were probably under nutritional stress in low intensity infections during rapid growth of the differentiating and differentiated procercoids.

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Identifying and mapping very small (<0.5 km2) mountain glaciers on coarse to high-resolution imagery

Journal of Glaciology ◽

10.1017/jog.2019.50 ◽

2019 ◽

Vol 65 (254) ◽

pp. 873-888 ◽

Cited By ~ 7

Author(s):

J. R. Leigh ◽

C. R. Stokes ◽

R. J. Carr ◽

I. S. Evans ◽

L. M. Andreassen ◽

...

Keyword(s):

Remote Sensing ◽

High Resolution ◽

Minimum Size ◽

Minimum Threshold ◽

Mountain Glaciers ◽

Seasonal Snow ◽

High Resolution Imagery ◽

Size Threshold ◽

Seasonal Snow Cover ◽

Consistent Approach

AbstractSmall mountain glaciers are an important part of the cryosphere and tend to respond rapidly to climate warming. Historically, mapping very small glaciers (generally considered to be <0.5 km2) using satellite imagery has often been subjective due to the difficulty in differentiating them from perennial snowpatches. For this reason, most scientists implement minimum size-thresholds (typically 0.01–0.05 km2). Here, we compare the ability of different remote-sensing approaches to identify and map very small glaciers on imagery of varying spatial resolutions (30–0.25 m) and investigate how operator subjectivity influences the results. Based on this analysis, we support the use of a minimum size-threshold of 0.01 km2 for imagery with coarse to medium spatial resolution (30–10 m). However, when mapping on high-resolution imagery (<1 m) with minimal seasonal snow cover, glaciers <0.05 km2 and even <0.01 km2 are readily identifiable and using a minimum threshold may be inappropriate. For these cases, we develop a set of criteria to enable the identification of very small glaciers and classify them as certain, probable or possible. This should facilitate a more consistent approach to identifying and mapping very small glaciers on high-resolution imagery, helping to produce more comprehensive and accurate glacier inventories.

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POPULASI DAN SERANGAN KUTU PUTIH PEPAYA, PARACOCCUS MARGINATUS (HEMIPTERA: PSEUDOCOCCIDAE) PADA TANAMAN PEPAYA DI DAERAH DATARAN RENDAH SUMATERA SELATAN

JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA ◽

10.23960/j.hptt.214136-141 ◽

2014 ◽

Vol 14 (2) ◽

pp. 136-141

Author(s):

Rosdah Thalib ◽

Rossi Fachrullah Rozi ◽

Triani Adam ◽

Khodijah Khodijah ◽

Siti Herlinda

Keyword(s):

Plant Species ◽

Rainy Season ◽

Host Plants ◽

Minimum Size ◽

Fruit And Vegetable ◽

Dicotyledonous Plant

Populations and damage by the papaya mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae) on papaya inlowland areas of South Sumatera. One of the main problems in papaya cultivation today is the presence of a newlyintroduced pest, the white papaya mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae). This study aimed toobserve the mealybug populations and its damage percentage in papaya plants and to identify its host plants in SouthSumatera. The study was carried out on the fruit and vegetable producing area in Indralaya, South Sumatera. The survey wasconducted on papaya plantation plots with a minimum size of 1000 m2. Data from the observation indicated that populationsof P. marginatus on papaya fruit were not significantly different to those on papaya leaves, except for the first observation inthe rainy season. In general, the percentages of mealybug damages were not affected by the season and the percentages ofdamage on the leaves were not different from those on the fruits of the papaya plants. Inventory of P. marginatus host plantson the area resulted in a total of 12 species of host plants dominated by dicotyledonous plant species. The host plants werefrom 11 families, i.e. Anacardiaceae, Caricaceae, Cucurbitaceae, Euphorbiaceae, Fabaceae, Myrtaceae, Rosaceae, Rutaceae,Sapindaceae, Sapotaceae, and Solanaceae.

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Reproductive size thresholds and seedling survival in Acacia harpophylla (Mimosaceae)

Australian Journal of Botany ◽

10.1071/bt17051 ◽

2017 ◽

Vol 65 (5) ◽

pp. 438

Author(s):

John M. Dwyer

Keyword(s):

Genetic Diversity ◽

Sexual Reproduction ◽

Population Genetic ◽

Seedling Recruitment ◽

Seedling Survival ◽

New South ◽

Minimum Size ◽

First Year ◽

South Wales ◽

Size Threshold

Acacia harpophylla F.Muell. ex Benth. (brigalow) forests and woodlands formerly occupied at least 8.7 M ha of Queensland and New South Wales, but less than 10% persists in isolated fragments and linear strips within a matrix of exotic beef pasture and dryland cropping. Given the relatively rapid and widespread clearing of brigalow forests, recent research has focussed on restoration via naturally resprouting vegetation. However, our understanding of A. harpophylla sexual reproduction and seedling recruitment remains poor. This study, undertaken following a widespread masting event in late 2007, aimed to (1) quantify initial densities of A. harpophylla germinants; (2) estimate subsequent seedling survival during the first year; and (3) determine minimum size thresholds for sexual reproduction in A. harpophylla. Initial densities averaged >46 000 seedlings ha–1, but only 438 seedlings ha–1 (<1%) were estimated to remain after a year. Although mortality was high, seedling recruitment is probably still sufficient to replace senescing stems and augment population genetic diversity to some extent. A reproductive size threshold of 10 cm diameter was identified, providing useful information to predict when naturally resprouting stands will begin to participate in masting events.

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Pollination efficiency of Apis mellifera Linnaeus, 1758 (Hymenoptera, Apidae) on the monoecious plants Jatropha mollissima (Pohl) Baill. and Jatropha mutabilis (Pohl) Baill. (Euphorbiaceae) in a semi-arid Caatinga area, northeastern Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842011000100016 ◽

2011 ◽

Vol 71 (1) ◽

pp. 107-113 ◽

Cited By ~ 6

Author(s):

EL. Neves ◽

BF. Viana

Keyword(s):

Apis Mellifera ◽

Plant Species ◽

High Efficiency ◽

The Body ◽

Northeastern Brazil ◽

Floral Resources ◽

Native Plant ◽

Pollination Efficiency ◽

Flower Visitation ◽

Low Efficiency

Previous studies have shown the superior competitive ability of honeybees compared with native bees in the exploitation of floral resources and nesting sites besides their low efficiency in pollinating native plant species. However, there is little evidence of the effect of this invading species on autochthonous plant populations in natural environments. Thus experiments were performed to test the pollination efficiency of honeybees in two species of Jatropha (Euphorbiaceae), J. mollissima (Pohl) Baill. and J. mutabilis (Pohl) Baill., after a single flower visitation. Samplings were carried out between March and April 2006 in a hyperxerophilous shrub-arboreal Caatinga at Estação Biológica de Canudos, Bahia (9º 56´ 34" S, 38º 59´ 17" W), the property of Fundação Biodiversitas. Apis mellifera was efficient at pollinating J. mollissima (100%) and J. mutabilis (85%). This high efficiency may be explained by 1) the simple floral characteristics of both plant species, which facilitate access to the sexual organs of the plant; and 2) the body size of A. mellifera that fits the flower's dimensions.

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Scaling of Program Fitness Spaces

Evolutionary Computation ◽

10.1162/evco.1999.7.4.399 ◽

1999 ◽

Vol 7 (4) ◽

pp. 399-428 ◽

Cited By ~ 19

Author(s):

William B. Langdon

Keyword(s):

Monte Carlo ◽

Side Effects ◽

Side Effect ◽

Building Blocks ◽

Monte Carlo Sampling ◽

Minimum Size ◽

Linear Programs ◽

Parse Trees ◽

Size Threshold ◽

Density Of Solutions

We investigate the distribution of fitness of programs concentrating on those represented as parse trees and, particularly, how such distributions scale with respect to changes in the size of the programs. By using a combination of enumeration and Monte Carlo sampling on a large number of problems from three very different areas, we suggest that, in general, once some minimum size threshold has been exceeded, the distribution of performance is approximately independent of program length. We proof this for both linear programs and simple side effect free parse trees. We give the density of solutions to the parity problems in program trees which are composed of XOR building blocks. Limited experiments with programs including side effects and iteration suggest a similar result may also hold for this wider class of programs.

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Preparation of integrated circuits for TEM electromigration in situ studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100145753 ◽

1986 ◽

Vol 44 ◽

pp. 882-883

Author(s):

J. V. Maskowitz ◽

W. E. Rhoden ◽

D. R. Kitchen ◽

R. E. Omlor ◽

P. F. Lloyd

Keyword(s):

Integrated Circuits ◽

Crystallographic Orientation ◽

Silicon Wafers ◽

Minimum Size ◽

Test Vehicle ◽

In Situ Studies ◽

Boron Doped ◽

Doped Silicon ◽

Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

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