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151.
Modifications of Hermissenda's phototactic behavior by compound pairings of light, scallop extract, and rotation were assessed. In general, the scallop extract potentiated phototactic suppression. Potentiation was dependent on (a) conjunctive presentations of scallop and light, (b) number of conditioning trials, and (c) scallop extract concentration. In related experiments, no second-order conditioning or sensory preconditioning of phototactic suppression was observed, indicating that within-compound associations did not contribute appreciably to potentiation. These results represent the first detailed analysis of compound conditioning in a mollusk using discrete presentations of well-characterized conditioned stimuli from distinct sensory modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
152.
Heron Reva L.; Twomey Heather B.; Jacobs Diana P.; Kaslow Nadine J. 《Canadian Metallurgical Quarterly》1997,34(4):410
This article focuses on interventions with low-income, African American women who are survivors of domestic abuse and who have made one or more suicide attempts. The authors review the literature on domestic abuse and suicidal behavior in African American women, and discuss the association between abuse and suicide in this population. Next, they propose an integrated theoretical model for understanding suicidal behavior as one possible coping response to the stress of a domestic abuse situation. The model utilizes concepts from the literature on stress and coping as well as stages of change. A culturally sensitive group treatment intervention that is based on the theoretical model is presented. The intervention focuses on ensuring women's safety, increasing coping skills and resource mobilization, and promoting supportive relationships in a manner that is consistent with each woman's sociocultural context. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
153.
Balasubramani GK Wisniewski SR Zhang H Eng HF 《Computer methods and programs in biomedicine》2005,79(2):179-187
When underlying distributions are unknown and sample sizes are small, permutation tests may have superior features to parametric tests, such as smaller type I error and more accurate probability values when testing the null hypothesis. However, permutation tests are not widely used in clinical trials because of their computational complexity. We developed an efficient SAS macro to generate all possible permutations of the data and to run subsequent permutation tests of difference between means for two independent samples. The macro performs permutation tests and provides the exact probability of significance for a wide range of statistics, including geometric means, medians, mid-ranges, mean-ranks, proportions and variances to meet the needs of data analysis in clinical trials. 相似文献
154.
Although long-chain fatty acyl-coenzyme A (LCFA-CoA) thioesters are specific high-affinity ligands for hepatocyte nuclear
factor-4α (HNF-4α) and peroxisome proliferator-activated receptor-α (PPARα), X-ray crystals of the respective purified recombinant
ligand-binding domains (LBD) do not contain LCFA-CoA, but instead exhibit bound LCFA or have lost all ligands during the purification
process, respectively. As shown herein: (i) The acyl chain composition of LCFA bound to recombinant HNF-4α reflected that
of the bacterial LCFA-CoA pool, rather than the bacterial LCFA pool. (ii) Bacteria used to produce the respective HNF-4α and
PPARα contained nearly 100-fold less LCFA-CoA than LCFA. (iii) Under conditions used to crystallize LBD (at least 3 wk at
room temperature in aqueous buffer), 16∶1-CoA was very unstable in buffer alone. (iv) In the presence of the respective nuclear
receptor (i.e., HNF-4α and PPARα), LBD 70–75% of 16∶1-CoA was degraded after 1 d at room temperature in the crystallization
buffer, whereas as much as 94–97% of 16∶1-CoA was degraded by 3 wk. (v) Cytoplasmic LCFA-CoA binding proteins such as acyl-CoA
binding protein, sterol carrier protein-2, and liver-FA binding protein slowed the process of 16∶1-CoA degradation proportional
to their respective affinities for this ligand. Taken together, these data for the first time indicated that the absence of
LCFA-CoA in the crystallized HNF-4α and PPARα was due to the paucity of LCFA-CoA in bacteria as well as to the instability
of LCFA-CoA in aqueous buffers and the conditions used for LBD crystallization. Furthermore, instead of protecting bound LCFA-CoA
from autohydrolysis like several cytoplasmic LCFA-CoA binding proteins, these nuclear receptors facilitated LCFA-CoA degradation. 相似文献
155.
156.
Foran Heather M.; Slep Amy M. Smith; Heyman Richard E. 《Canadian Metallurgical Quarterly》2011,79(3):391
Objective: Intimate partner violence (IPV) is a serious health concern, but little is known about prevalence of IPV in the armed forces, as military members cope with the pressures of long-standing operations. Furthermore, previous prevalence studies have been plagued by definitional issues; most studies have focused on acts of aggression without consideration of impact (clinically significant [CS] IPV). This is the first large-scale study to examine prevalences of IPV, CS-IPV, and clinically significant emotional abuse (CS-EA) for men and women. Method: A United States Air Force-wide anonymous survey was administered across 82 bases in 2006 (N = 42,744) to assess IPV, CS-IPV, and CS-EA. Results: The adjusted prevalence of CS-IPV perpetration was 4.66% for men and 3.54% for women. Prevalences of IPV perpetration were 12.90% for men and 15.14% for women. CS-EA victimization was 6.00% for men and 8.50% for women. Sociodemographic differences in risk for violence were found for gender, race/ethnicity, pay grade, religious faith, marital status, and career type even after controlling for other demographic variables. Conclusions: Partner maltreatment is widespread in military (and civilian) samples. Men were more likely to perpetrate CS-IPV, whereas women were more likely to perpetrate IPV. Specific demographic risk factors were identified for different types of partner maltreatment (e.g., lower rank predicted higher risk for both perpetration and victimization across men and women). Other sociodemographic differences varied across severity (IPV vs. CS-IPV) and across gender. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
157.
Renewable and low carbon fuel standards being developed at federal and state levels require an estimation of the life cycle carbon intensity (LCCI) of candidate fuels that can substitute for gasoline, such as second generation bioethanol. Estimating the LCCI of such fuels with a high degree of confidence requires the use of probabilistic methods to account for known sources of uncertainty. We construct life cycle models for the bioconversion of agricultural residue (corn stover) and energy crops (switchgrass) and explicitly examine uncertainty using Monte Carlo simulation. Using statistical methods to identify significant model variables from public data sets and Aspen Plus chemical process models,we estimate stochastic life cycle greenhouse gas (GHG) emissions for the two feedstocks combined with two promising fuel conversion technologies. The approach can be generalized to other biofuel systems. Our results show potentially high and uncertain GHG emissions for switchgrass-ethanol due to uncertain CO? flux from land use change and N?O flux from N fertilizer. However, corn stover-ethanol,with its low-in-magnitude, tight-in-spread LCCI distribution, shows considerable promise for reducing life cycle GHG emissions relative to gasoline and corn-ethanol. Coproducts are important for reducing the LCCI of all ethanol fuels we examine. 相似文献
158.
Adam M Leventhal Susan E Ramsey Richard A Brown Heather R LaChance Christopher W Kahler 《Nicotine & tobacco research》2008,10(3):507-517
Because different psychopathologic components of depressive symptoms may have distinct etiologies, examining their differential effects on smoking cessation may elucidate mechanisms underlying the smoking-depression relationship. Negative affect (NA), somatic features (SF), low positive affect/anhedonia (PA), and interpersonal disturbance (IP) have been identified as unique dimensions of depression that can be measured using the Center for Epidemiologic Studies Depression Scale (CESD). This study examined common and unique associations between CESD subscales and baseline smoking characteristics, nicotine withdrawal, and relapse in 157 participants enrolled in a smoking cessation trial for heavy social drinkers. Each dimension was univariately associated with negative and positive reinforcement smoking motives. Only SF had unique relations with tolerance smoking motives and univariate associations with nicotine dependence severity. Only PA predicted cessation-related changes in withdrawal symptoms on quit day. Analyses predicting abstinence at 8, 16, and 26 weeks post quit date showed that NA, SF, and PA each univariately predicted relapse, ps< or =.0083. Only low PA predicted poorer outcomes incrementally to the other dimensions, even when controlling for level of nicotine dependence, smoking frequency, and history of major depression, p = .0018. Interventions targeting anhedonia and low positive affect may be useful for smokers trying to quit. 相似文献
159.
Stapleton HM Allen JG Kelly SM Konstantinov A Klosterhaus S Watkins D McClean MD Webster TF 《Environmental science & technology》2008,42(18):6910-6916
Due to the voluntary withdrawals and/or bans on the use of two polybrominated diphenyl ether (PBDE) commercial mixtures, an increasing number of alternate flame retardant chemicals are being introduced in commercial applications. To determine if these alternate BFRs are present in indoor environments, we analyzed dust samples collected from 19 homes in the greater Boston, MA area during 2006. Using pure and commercial standards we quantified the following brominated flame retardant chemicals using GC/ECNI-MS methods: hexabromocyclododecane (sigma HBCD), bis(2,4,6,-tribromphenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and the brominated components found in Firemaster 550 (FM 550): 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) and (2-ethylhexyl)tetrabromophthalate (TBPH), the latter compound being a brominated analogue of di(2-ethylhexyl)phthalate (DEHP). The concentrations of all compounds were log-normally distributed and the largest range in concentrations was observed for HBCD (sum of all isomers), with concentrations ranging from <4.5 ng/g to a maximum of 130,200 ng/g with a median value of 230 ng/g. BTBPE ranged from 1.6 to 789 ng/g with a median value of 30 ng/g and DBDPE ranged from <10.0 to 11,070 ng/g with a median value of 201 ng/g. Of the FM 550 components, TBB ranged from <6.6 to 15,030 ng/g with a median value of 133 ng/g; whereas TBPH ranged from 1.5 to 10,630 ng/g with a median value of 142 ng/g. Furthermore, the ratio of TBB/TBPH present in the dust samples ranged from 0.05 to 50 (average 4.4), varying considerably from the ratio observed in the FM 550 commercial mixture (4:1 by mass), suggesting different sources with different chemical compositions, and/or differential fate and transport within the home. Analysis of paired dust samples collected from different rooms in the same home suggests HBCD, TBB, and TBPH are higher in dust from the main living area compared to dust collected in bedrooms; however, BTBPE and DBDPE levels were comparable between rooms. This study highlights the fact that numerous types of brominated flame retardants are present in indoor environments, raising questions about exposure to mixtures of these contaminants. 相似文献
160.
Stuart C. Burgess David F. Moore David E. Newland Heather L. Klaubert 《Research in Engineering Design》1997,9(1):46-60
This paper shows that there are three main categories of factors that make the optimum mechanical design of micro-systems different from macro-systems: scale effects, a limited range of materials, and a limited range of production processes. The combined effect of these factors can make the optimum configuration of a micro-system potentially very different from that of the same system on a macro-scale. In particular, the use of flexible elements for hinges is much more feasible and desirable on a micro-scale.Notation
a
acceleration (m/s2)
-
A
cross-sectional area (m2)
-
B
magnetic flux [wb/m2]
-
b
width [m]
-
C
constant
-
d
depth [m]
-
D
drag [N]
-
E
Young's modulus [N/m2]
-
E*=
-
f
resonant frequency [Hz]
-
F
D
drive force [N]
-
F
E
electrostatic pulling force [N]
-
F
emmisivity function
-
F
G
geometric view factor
-
g
gravitational constant [m/s2]
-
h
c
convention heat transfer coefficient [W/m2K]
-
h
height [m]
-
i
current [A]
-
I
A
second moment of area [m4]
-
I
I
moment of inertia [kg m2]
-
J
polar second moment of area [m4]
-
k
stiffness [N/m]
-
K
thermal conductivity [W/m K]
-
l
length [m]
-
m
mass [kg]
-
M
moment [N m]
-
P
load [N]
-
P
H
Hertz contact pressure [N/m2]
-
P
C
cylinder pressure [N/m2]
-
q
heat transfer rate [W]
-
R, r
radius [m]
-
Re
Reynolds number
-
T, t
temperature [K]
-
T
A
atomic friction torque [N m]
-
T
D
drive torque [N m]
-
T
F
Coulomb friction torque [N m]
-
T
I
inertial resistive torque [N m]
-
u
velocity [m/s]
-
mean velocity [m/s]
-
V
volume [m3]
-
V
e
voltage [V]
-
x
distance between electrodes [m]
-
y
maximum distance to neutral axis [m]
-
angular acceleration [rad/s2]
-
d
thermal diffusivity [1/K]
-
rolling friction factor
- P
pressure difference [N/m2]
-
0
dialectric constant [F/m]
-
strain
-
dynamic viscosity [Pa s]
-
scale factor
-
S
coefficient of sliding friction
-
R
coefficient of rolling friction
-
1, 2
Poisson's ratio
-
density (kg/m3)
-
temperature rise [°C]
-
B
bending stress [N/m2]
-
y
yield strength [N/m2]
-
shear stress [N/m2]
-
reliability constant 相似文献