scholarly journals Relationships between four Neotropical species of galling insects and shoot vigor

1999 ◽  
Vol 28 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Silmary J. Gonçalves-Alvim ◽  
Maurício L. Faria ◽  
Geraldo W. Fernandes
Keyword(s):  
Positive Relationship ◽  
Unit Length ◽  
Shoot Length ◽  
Response Patterns ◽  
Offspring Performance ◽  
Neotropical Species ◽  
Attack Pattern ◽  
Galling Insects ◽  
Vigorous Plant ◽  
Plant Vigor Hypothesis

The plant-vigor hypothesis (PVH) predicts that females of galling insects preferentially oviposit on the most vigorous plant or plant modules, where their offspring performance is highest. We tested the PVH on Neopelma baccharidis Buckhardt (Homoptera: Psyllidae) and Rhoasphondylia friburgensis Tavares (Diptera: Cecidomyiidae) which induce galls on Baccharis dracunculifolia D.C. (Asteraceae), and on two different Cecidomyiidae (Diptera) species that induce galls on Maytenus salicifolia Reiss. (Celastraceae) and Vernonia polyanthes Less (Asteraceae), respectively. The abundance of galls induced by the four galling species increased with increasing shoot length, as predicted by the PVH. However, when we considered the rate of attack per shoot unit length (cm), which includes in the analyses the effect of availability of resource per unit length, the response patterns of the four gallers disappeared. R. friburgensis and Cecidomyiidae species which cause galls on M. salicifolia did not respond to shoot vigor (P > 0.05) while the other species responded differentially. The abundance of N. baccharidis galls correlated negatively with shoot length (y = 0.185 - 0.007x, r² = 0.21, F = 6.013, P < 0.05) while the number of galls caused by Cecidomyiidae on V. polyanthes showed a positive relationship with shoot vigor (y = 0.09 + 0.002x, r² = 0.34, F = 6.157, P < 0.05). Hence, only the attack pattern of the cecidomyiid galler on V. polyanthes corroborated the PVH.

Student Thoughts during Tennis Instruction

1992 ◽  
Vol 11 (3) ◽  
pp. 256-267 ◽  
Author(s):  
Amelia M. Lee ◽  
Dennis K. Landin ◽  
Jo A. Carter
Keyword(s):  
Positive Relationship ◽  
Student Response ◽  
Response Patterns ◽  
Practice Session ◽  
Successful Performance ◽  
Significant Positive Relationship ◽  
Stimulated Recall ◽  
Fourth Grade Students ◽  
Recall Procedure ◽  
Practice Trials

Thirty fourth-grade students were provided two 30-min lessons on the tennis forehand ground stroke. The students and the teacher were videotaped, and, following each lesson, the students were interviewed using a stimulated-recall procedure. Frequency measures of successful practice trials were also coded for each student during each practice session. Analysis revealed a significant positive relationship between skill-related thoughts and successful performance during class. The findings support the notion that student thoughts are important mediators between instruction and student response patterns.

scholarly journals Galling insects on neotropical species ofBaccharis(Asteraceae)

1996 ◽  
Vol 9 (2) ◽  
pp. 315-332 ◽  
Author(s):  
G. W. Fernandes ◽  
M. A.A. Carneiro ◽  
A. C.F. Lara ◽  
L. R. Allain ◽  
G. I. Andrade ◽  
...  
Keyword(s):  
Neotropical Species ◽  
Galling Insects

Variation in shoot growth components among western larch families

1993 ◽  
Vol 23 (8) ◽  
pp. 1520-1527 ◽  
Author(s):  
Jian-Wei Zhang ◽  
Lauren Fins
Keyword(s):  
Shoot Growth ◽  
Unit Length ◽  
Tree Height ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Western Larch ◽  
Growing Seasons ◽  
Free Growth ◽  
Terminal Shoot ◽  
Highly Correlated

Shoot growth components, including predetermined growth, free growth, number of stem units, and mean stem unit length, were evaluated over two growing seasons (8th and 9th) for their contribution to variation in lateral shoot length of 14 families of western larch (Larixoccidentalis Nutt.). All families produced some free growth stem units in both years, averaging 21 and 20% of the total number of stem units in years 8 and 9, respectively. Significant variation was detected among families in total number of stem units and predetermined growth stem units in both years, in mean stem unit length and terminal shoot length at age 8, and in lateral shoot length and tree height at age 9. Lateral shoot length and terminal shoot length were highly correlated with each other, as well as with the total number of stem units and predetermined growth stem units in the lateral shoot. Free growth stem units in the lateral shoot at ages 8 and 9 were not significantly correlated with 8- and 9-year terminal shoot growth or height at age 9. However, the total number of stem units in lateral shoots was well correlated with 8- and 9-year terminal shoot length and with 9-year height. The implications of these results for early selection for increased height growth are discussed.

Age-related changes in shoot growth components of Great Basin bristlecone pine

1989 ◽  
Vol 19 (7) ◽  
pp. 933-935 ◽  
Author(s):  
Kristina F. Connor ◽  
Ronald M. Lanner
Keyword(s):  
Great Basin ◽  
Shoot Growth ◽  
Unit Length ◽  
Shoot Length ◽  
Tree Age ◽  
White Mountains ◽  
Age Related ◽  
Bristlecone Pine ◽  
Pine Trees ◽  
Age Related Changes

Shoots were collected from various-aged Great Basin bristlecone pine trees (Pinuslongaeva D.K. Bailey) at three locations to determine whether shoot growth, stem unit production, and stem unit length decreased with increasing tree age. Trees from a southern Utah site were 14–2052 years old, whereas those from two White Mountains, California, locations were 824–4712 years old. Variation in shoot length, stem unit production, and stem unit length were not significant when regressed on tree age (r2 = 0.010–0.237). The fact that shoots from older trees showed no sign of reduced growth when compared with those from younger trees suggests that diminishment of annual shoot increment is not a definitive sign of aging in Great Basin bristlecone pine.

scholarly journals Where host plant goes, galls go too: new records of the Neotropical galling Cecidomyiidae (Diptera) associated with Calophyllum brasiliense Cambess. (Calophyllaceae)

Check List ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1924
Author(s):  
Ígor Abba Arriola ◽  
João Carlos Ferreira de Melo Júnior ◽  
Denise Monique Dubet da Silva Mouga ◽  
Rosy Mary Dos Santos Isaias ◽  
Elaine Cotrim Costa
Keyword(s):  
Host Plant ◽  
New Records ◽  
Field Sampling ◽  
Neotropical Species ◽  
Calophyllum Brasiliense ◽  
Galling Insects

Calophyllum brasiliense, a Neotropical species, hosts seven galling Cecidomyiidae reported only for Brazil. Our hypothesis is the distribution of the galling insects associated with C. brasiliense is similar to that of the host plant. We checked gall occurrence by field sampling and by searching data in literature and herbaria. Current results indicate that the occurrence of galling Cecidomyiidae associated with C. brasiliense extends to 13 Brazilian states, as well as to 11 countries of Neotropical America.

Relationships between shoot length and shoot length components in Douglas-fir and blue spruce

1986 ◽  
Vol 16 (2) ◽  
pp. 373-380 ◽  
Author(s):  
Bruce Bongarten
Keyword(s):  
Unit Length ◽  
Tree Height ◽  
Douglas Fir ◽  
Shoot Length ◽  
Environmental Data ◽  
Lateral Shoot ◽  
Growth Physiology ◽  
Blue Spruce ◽  
Provenance Test ◽  
Sources Of Variation

Number of stem units (NSU) and mean stem unit length (MSUL) were examined for their influence on first-order lateral shoot length in a 14-year-old, range-wide provenance test of interior Douglas-fir and an 8-year-old, range-wide provenance–progeny test of blue spruce. The degree to which each component influenced variation in shoot length depended on (i) the population, (ii) the level of population structure (between and within provenances), and (iii) whether phenotypic, genotypic, or environmental data were considered. In Douglas-fir, northern and southern trees were consistently different in MSUL. However, in northern and southern Douglas-fir considered separately and in blue spruce, provenance differences in shoot length were primarily due to variation in NSU. Within provenances, phenotypic variation in shoot length was caused equally by MSUL and NSU in both Douglas-fir and blue spruce. However, in blue spruce, genetic variation was mostly due to the MSUL component, while environmental variation was caused primarily by the NSU component. As a result, MSUL had a higher heritability than NSU. MSUL was also well correlated with tree height (within provenances) while NSU was not. MSUL and NSU were negatively correlated among provenance means, within provenances, on a phenotypic, genetic, or environmental basis. This limits the usefulness of these components as selection criteria and emphasizes the need for better understanding of shoot growth physiology to identify independent sources of variation in growth rate.

scholarly journals Plant Vigor Hypothesis refuted: preference-performance linkage of a gall-inducing weevil on small-sized host plant resources

2011 ◽  
Vol 71 (1) ◽  
pp. 65-69 ◽  
Author(s):  
JC. Santos ◽  
CB. Tavares ◽  
JS. Almeida-Cortez
Keyword(s):  
Host Plant ◽  
Oviposition Preference ◽  
Leaf Size ◽  
Leaf Length ◽  
Larval Performance ◽  
Top Down ◽  
Plant Resources ◽  
Offspring Performance ◽  
Plant Vigor ◽  
Plant Vigor Hypothesis

The Plant Vigor Hypothesis (PVH) predicts an oviposition preference of females and higher offspring performance for insect herbivores on longer and fast-growing plant modules. We tested the PVH predictions by investigating the effects of leaf size of Miconia prasina (Sw.) DC. (Melastomataceae) on the oviposition preference and on the offspring survival of the gall-inducing weevil Prospoliata bicolorata (Coleoptera: Curculionidae). Additionally, we analysed the effects of top-down mortality force on this system. Approximately 83% of the developed galls resulted in adults of P. bicolorata, whereas 17% of the galls successfully induced were killed by natural enemies (top-down effect). Leaves of intermediate size were more abundant while smaller and longer leaves were rare. Nevertheless, the percentage of P. bicolorata galls was higher on the smallest leaves of M. prasina, refuting the preference prediction of the PVH. Our results also refuted the performance prediction: the ratio of survival per leaf was negatively related to the leaf length. Thus, we found a link between female preference and larval performance of P. bicolorata on small-sized leaves of M. prasina. The next goal is to understand the mechanisms involved in the selection of gall-inducing weevil on short leaves of its host plant.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

Stimulus Ratio Effects on Speech Discrimination by Children and Adults

1991 ◽  
Vol 34 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Joan E. Sussman
Keyword(s):  
Discrimination Task ◽  
Response Pattern ◽  
Response Patterns ◽  
Speech Discrimination ◽  
Adult Group ◽  
Discrimination Accuracy ◽  
Formant Frequency ◽  
Response Strategies ◽  
Place Of Articulation ◽  
Adults And Children

This investigation examined the response strategies and discrimination accuracy of adults and children aged 5–10 as the ratio of same to different trials was varied across three conditions of a “change/no-change” discrimination task. The conditions varied as follows: (a) a ratio of one-third same to two-thirds different trials (33% same), (b) an equal ratio of same to different trials (50% same), and (c) a ratio of two-thirds same to one-third different trials (67% same). Stimuli were synthetic consonant-vowel syllables that changed along a place of articulation dimension by formant frequency transition. Results showed that all subjects changed their response strategies depending on the ratio of same-to-different trials. The most lax response pattern was observed for the 50% same condition, and the most conservative pattern was observed for the 67% same condition. Adult response patterns were most conservative across condition. Differences in discrimination accuracy as measured by P(C) were found, with the largest difference in the 5- to 6-year-old group and the smallest change in the adult group. These findings suggest that children’s response strategies, like those of adults, can be manipulated by changing the ratio of same-to-different trials. Furthermore, interpretation of sensitivity measures must be referenced to task variables such as the ratio of same-to-different trials.

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