11,043 research outputs found
Relationship between water quality, watermilfoil frequency, and weevil distribution in the State of Washington
During the summer of 1997, we surveyed 50 waterbodies
in Washington State to determine the distribution of the
aquatic weevil
Euhrychiopsis lecontei
Dietz. We collected data
on water quality and the frequency of occurrence of watermilfoil
species within selected watermilfoil beds to compare
the waterbodies and determine if they were related to the
distribution
E. lecontei
. We found
E. lecontei
in 14 waterbodies,
most of which were in eastern Washington. Only one lake
with weevils was located in western Washington. Weevils were
associated with both Eurasian (
Myriophyllum spicatum
L.) and
northern watermilfoil (
M. sibiricum
K.). Waterbodies with
E.
lecontei
had significantly higher (
P
< 0.05) pH (8.7
±
0.2)
(mean
±
2SE), specific conductance (0.3
±
0.08 mS cm
-1
) and
total alkalinity (132.4
±
30.8 mg CaCO
3
L
-1
). We also found
that weevil presence was related to surface water temperature
and waterbody location ( = 24.3,
P
≤
0.001) and of all
the models tested, this model provided the best fit (Hosmer-
Lemeshow goodness-of-fit = 4.0,
P
= 0.9). Our results suggest
that in Washington State
E. lecontei
occurs primarily in
eastern Washington in waterbodies with pH
≥
8.2 and specific
conductance
≥
0.2 mS cm
-1
. Furthermore, weevil distribution
appears to be correlated with waterbody location (eastern
versus western Washington) and surface water temperature
Alien Registration- Hamel, Pierre E. (Sanford, York County)
https://digitalmaine.com/alien_docs/3427/thumbnail.jp
Science starts early: A literature review examining the influence of early childhood teachers’ perceptions of gender on teaching practices
Women are underrepresented in science fields as compared to men and although much research has been dedicated to understanding this disparity, most has been conducted on older aged children. However, this excludes the youngest and arguably most impressionable group of students: preschoolers. This study reviewed the literature to investigate how early childhood teachers’ perceptions of gender influence their teaching practices. Qualitative analysis and coding of 31 articles resulted in five main categories: Teacher Perception, Curriculum, Teacher Interactions, Gender Identity, and Social Standing. Results are discussed in the context of early childhood science teaching practices to better understand the role of the teacher and gender bias in young children’s preschool science experiences and how it may impact their future science interests
To what extent do the Classical Equations of Motion Determine the Quantization Scheme?
A simple example of one particle moving in a (1+1) space-time is considered.
As an example we take the harmonic oscillator. We confirm the statement that
the classical Equations of Motion do not determine at all the quantization
scheme. To this aim we use two inequivalent Lagrange functions, yielding
Euler-Lagrange Equations, having the same set of solutions. We present in
detail the calculations of both cases to emphasize the differences occuring
between them.Comment: LaTeX 20 page
Causal Modeling of Organizational Commitment
This research was designed to develop a model of organizational commitment by establishing a causal network among three individual characteristics--tenure, work motivation, and job satisfaction--two organizational/structural variables--decentralization and formalization,--and two job facets--the job characteristic model and job stress--as determinants of commitment.
The proposed model was tested on male and female samples represented by five occupational groups ranging from blue collar to professional workers. Successive iterations of a path analytic technique indicated that across the five occupational categories, job satisfaction was the single most important determinant of organizational commitment. However, if the facets of job satisfaction were examined more closely, important differences became apparent. Both blue collar and professional women reported that satisfaction with supervision determined, in part, their identification with organizational goals. Blue collar and white collar female employees, on the other hand, indicated that pay/promotion satisfaction was most important to them. Finally, the two male samples shared satisfaction with supervision and pay.
Among the remaining individual determinants of organizational commitment, tenure demonstrated a significant correlation with commitment among professional men and women as well as white collar men. Work motivation made significant contributions to commitment in blue and white collar women as well as white collar men but was negatively correlated with commitment in male professional. Of the two organizational/structural variables, decentralization did not attain significance in any of the female samples but affected commitment in white collar males whereas formalization had a significant impact on both the professional and white collar male sample. Predictions regarding the job characteristic model were, by and large, not supported while several of the job stress variables accounted for variance in organizational commitment. Overall, the proposed model provided the best fit for the male samples and identified important differences between male and female employees as well as among members of different occupational classes. Taken together, the results suggested the need for a further conceptual development and refinement of the commitment construct as well as a re-examination of the job characteristic model for female employees
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