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The objective of this study was to present nationally representative findings on sociodemographic and psychopathologic predictors of first incidence of Diagnostic and Statistical Manual of Mental Disorders, 4th edn (DSM-IV) substance, mood and anxiety disorders using the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. One-year incidence rates of DSM-IV substance, mood and anxiety disorders were highest for alcohol abuse (1.02), alcohol dependence (1.70), major depressive disorder (MDD; 1.51) and generalized anxiety disorder (GAD; 1.12). Incidence rates were significantly greater (P<0.01) among men for substance use disorders and greater among women for mood and anxiety disorders except bipolar disorders and social phobia. Age was inversely related to all disorders. Black individuals were at decreased risk of incident alcohol abuse and Hispanic individuals were at decreased risk of GAD. Anxiety disorders at baseline more often predicted incidence of other anxiety disorders than mood disorders. Reciprocal temporal relationships were found between alcohol abuse and dependence, MDD and GAD, and GAD and panic disorder. Borderline and schizotypal personality disorders predicted most incident disorders. Incidence rates of substance, mood and anxiety disorders were comparable to or greater than rates of lung cancer, stroke and cardiovascular disease. The greater incidence of all disorders in the youngest cohort underscores the need for increased vigilance in identifying and treating these disorders among young adults. Strong common factors and unique factors appear to underlie associations between alcohol abuse and dependence, MDD and GAD, and GAD and panic disorder. The major results of this study are discussed with regard to prevention and treatment implications. [ABSTRACT FROM AUTHOR]

Abstract  The effects of superimposed, low-frequency modulation on contact conditions at the tool–chip interface and mechanics of machining are analyzed. It is shown that modulation can disrupt the severity of the tool–chip contact, enabling enhanced lubrication of this contact; and discretize chip formation to small dimensions with controlled size and shape. The deformation strain in the chip is also reduced, suggesting a 40% reduction in energy of machining due to the modulation. Conditions of frequency and amplitude for achieving these effects are presented and confirmed using a compact modulation device that can be retro-fitted onto conventional machine platforms. Implications for enhancing efficiency of industrial machining processes are briefly discussed. [ABSTRACT FROM AUTHOR]

Nanostructured materials, composed of sub-micron sized grains (crystals), show novel attributes not commonly found in their microcrystalline counterparts. Furthermore, these attributes can be varied by changing the grain size. Nanostructured solids have high hardness, strength and ductility; and interesting electrical and magnetic properties. Superplasticity has been observed at relatively low temperatures in some of these materials [1]. Many new and exciting applications of these materials have been sought; however, the cost of creating these materials, frequently quoted in excess of three hundred euros per kilogram [2], and an inability to make these on a large-scale with reproducible properties have restricted their broad application. We describe new machining-based manufacturing processes for making nanostructured alloys that are likely to be much less expensive. These processes are structured around chip formation by large-strain machining. It has been found that chips of a variety of metals and alloys produced during normal machining operations are composed entirely of nanocrystalline and/or ultrafine grained (UFG) structures of high hardness and strength [3-5]. Furthermore, by imposing a constraint to the chip at the point of its formation, it is feasible to produce nanostructured metals and alloys directly in bulk forms (e.g., sheet, bar, foil); the constrained chip formation process is called large-strain extrusion machining [6]. [ABSTRACT FROM AUTHOR]

Plane-strain machining can be used to impart large plastic strains in alloys that are difficult to deform by other severe plastic deformation (SPD) processes. By cutting at low speeds, the heating caused by friction with the tool can be reduced to insignificant levels. The utility of this approach for characterizing microstructure development in SPD is demonstrated using a variety of commercial alloys that exhibit different deformation behaviors and strengthening mechanisms, including CP-titanium, aluminum alloy 6061-T6, nickel-base superalloy IN-718, and pearlitic plain-carbon steel. [ABSTRACT FROM AUTHOR]

Large plastic strains between 1 and 15 can be imposed in chips formed by plane-strain (2-D) machining of metals and alloys. This approach has been used to examine microstructure changes induced by large strain deformation in model systems—copper and its alloys, precipitation-hardenable aluminum alloys, high-strength materials such as titanium, Inconel 718 and 52100 steel, and an amorphous alloy. It is shown that materials with average grain sizes in the range of 60 nm–1 μm can be created by varying the parameters of machining, which in turn affects the deformation processes. Furthermore, a switch-over from an elongated subgrain microstructure to an equi-axed nanocrystalline microstructure, with a preponderance of large-angle grain boundaries, has been demonstrated at the higher levels of strain in several of these materials. This switch-over can be readily controlled by varying the deformation conditions. Dynamic recrystallization has been demonstrated in select material systems under particular conditions of strain and temperature. This study may be seen as providing an important bridge between furthering the understanding of microstructural refinement by large strain deformation and the practical utilization of nanostructured materials in structural and mechanical applications. Conventional plane-strain machining has been shown to be a viable SPD method for examining the underlying processes of very large strain deformation. [ABSTRACT FROM AUTHOR]

Measurement of strain field in the primary deformation zone is of major interest for development of machining as an experimental technique for studying phenomena associated with large strain deformation. A study has been made of the primary deformation zone and tool-chip interface in planestrain (two-dimensional) machining of metals. The use of a high-speed, charge-coupled device (CCD) imaging system in conjunction with an optically transparent, sapphire cutting tool has enabled characteristics of the deformation field such as velocity, strain, and material flow, to be obtained at high spatial and temporal resolution. The velocity distributions in the primary deformation zone and along the tool rake face have been obtained by applying a particle image velocimetry (PIV) technique to sequences of high-speed images of the chip-tool interface taken through the transparent tool, and of the primary deformation zone recorded from a side of the workpiece. A procedure is presented and demonstrated for determining the strain and strain rate distributions in the primary deformation zone. The measurements have provided data about the variations of velocity, strain rate, and strain, in and around the cutting edge and primary deformation zone: confirmed the existence of a region of retarded sliding in the region of intimate contact between tool and chip; and highlighted the occurrence of a region of dead metal ahead of the cutting edge when cutting with a negative rake angle tool. [ABSTRACT FROM AUTHOR]

Little is known about gambling rates of drug users recruited from drug treatment compared with those recruited from the community. We use the Diagnostic Interview Schedule (DIS) to provide lifetime prevalence estimates of problem gambling (i.e., at least one gambling problem) and DSM-III-R pathological gambling (i.e., at least four gambling problems) and describe the association between gambling and psychiatric disorders for drug users recruited from drug treatment settings (n = 512) and from the community (n = 478). We also report the relative risk of being a recreational and problem gambler in this sample. The sample was first interviewed in 1989–90 as a partof two NIDA-funded St. Louis-based studies. The prevalence of problem gambling in the overall sample was 22% and the prevalence of pathological gambling was 11%. There were no statistically significant differences in problem and pathological gambling rates for subjects recruited from drug treatment and those recruited from the community. The conditional prevalence rates, that is, the rate of problem and pathological gambling only among gamblers were 27% and 13.5%, respectively. Major findings indicate that problem gambling was associated with Antisocial Personality Disorder (ASPD), even after controlling for recruitment source and socio-demographic characteristics. In fact, when examining the temporal order of these disorders, we found that pathological gambling was always secondary to ASPD, occurring on average 11.4 years after the onset of ASPD. Problem gamblers, compared with everyone else, were more likely to be male, African-American, recruited from drug treatment, have ASPD and be dependent on illicit drugs. Multinomial logistic regression analysis predicted the relative risk of being a recreational and problem gambler (compared with a nongambler) in this sample according to socio-demographics, ASPD, and dependence on illicit drugs. Results imply that screening for gambling problems will need to be broad-based among drug users. [ABSTRACT FROM AUTHOR]

To identify reasons for discrepancies between parent and child reports of child/adolescents's psychiatric symptoms, parents and adolescents (51 pairs) were asked to guess what the other would answer to questions from the PC-DISC about the adolescent's psychiatric symptoms, and to explain why they expected disagreement when the answer they provided for the other was different from their own. Adolescents' explanations for expecting (1) parental denial of symptoms the adolescent reported were: the parent was unaware of, forgot about, assumed the adolescent could not have, or trivialized the symptom; and (2) parental report of symptoms the adolescent denied were: the parent misread or exaggerated the adolescent's symptom, had too high expectations for the adolescent's behavior, put a negative label on or did not trust the adolescent. Parents' reasons for expecting their children to (1) deny symptoms the parents reported were: the adolescent did not remember how s/he felt, lied, did not recognize or minimized the importance or frequency of the symptom; and (2) report symptoms the parents denied were: the adolescent lied, exaggerated the importance of or interpreted the symptom differently. [ABSTRACT FROM AUTHOR]

Four experimental single-cross hybrids were evaluated for intergenotypic competition in a split-plot design with 7 replicates and a stand density of 51,700 plants/hectar in 1970, 1971 and 1972 at Lincoln, Nebraska. The arrangement of rows used in this study allowed the measurement of effects of different levels of competition on the traits grain yield, plant height and a selection index. There were some definite inter-genotypic competitive effects for all three traits among the pairs of hybrids studied. Variation in types of intergenotypic interaction was found. A two-step process was suggested to take advantage of favorable competitive interactions for increasing grain yield. Failure of mixtures in corn to take advantage of favorable competitive situations was discussed. [ABSTRACT FROM AUTHOR]

Design II progenies from an exotic population of corn ( Zea mays L.) were evaluated in a randomized incomplete block design with two replications at two plant-population densities (17,222 plants/ha and 68,888 plants/ha) in 1970 and 1971, at Lincoln, Nebraska. Five traits were studied, i.e., grain weight, number of ears, days to flower, plant height, and ear height. It was suggested that a trait such as grain weight should be expressed on a unit area basis in the following situations: The estimates of genetic parameters were used to compute the expected direct and indirect genetic changes in grain weight and other traits from selection for grain weight. Three selection schemes were compared, i.e. mass selection (M.S.), full-sib (F.S.) selection, and half-sib (H.S.) selection in which S seeds from the selected male parents are used for recombination. A ten year selection program was considered. F.S. selection appears to be the most promising of the three, if there are no practical limitations and if costs are disregarded. A high-density selection environment appears to be a little better than a low density one for family selection. Mass selection at low density may result in good gains when measured at higher densities. From a long term point of view, it is possible that selection at low densities could allow response to continue for a longer period of time and perhaps reach a higher selection limit than selection at higher densities. Long term selection studies are necessary to compare response to high and low density-selection. [ABSTRACT FROM AUTHOR]

Variation in recombination rate is important to plant breeders since a major objective is to obtain favorable recombinants of linked genes. The ability to increase recombination (R) in circumstances in which favorable and unvavorable genes are linked (Corn Belt x exotic populations) and to decrease recombination when many favorable genes are linked (narrow-based, elite populations) would be of immense value. However, the concept of variation in recombination frequencies between linked genes has received limited attention despite its implications in breeding and genetic linkage studies. Molecular techniques have allowed better estimations of this variation. In this study, attempts were made to characterize: (1) the R values in the Pgm1-Adh1 and Adh1-Phi1 adjacent regions of chromosome 1 and the Idh2-Mdh2 region of chromosome 6 in F families of three maize ( Zea mays L.) populations; (2) the environmental effect on R values of Fs from two populations. One population, NSO, was a Corn Belt synthetic, and the other two populations, CBMEX3 and CBCAR5, were composites from crosses between Corn Belt and exotic germ-plams. Wide ranges of estimated recombination ( $$\hat R$$ ) values were observed among families in each population for all three chromsomal regions. The distribution of $$\hat R$$ values for the Pgm1-Adh1 region showed that the F families of each population fell into two broad categories: 0.30-0.50 and 0.02-0.20. No intermediates (0.21-0.29) were found. The distributions were almost normal for the Adh1-Phi1 and the Idh2-Mdh2 regions. It would appear that the major dispersion in the Pgm1-Adh1 region was controlled by the effects of a single gene, while the Adh1-Phi1 and Idh2-Mdh2 regions were only affected by polygenes. No correlation was found between recombination values of the two adjacent regions, indicating that the genes affecting recombination for the Pgm1-Adh1 region may be specific for that region. For the Pgm1-Adh1 region, no differences in $$\hat R$$ values were found among the three populations. For the Adh1-Phi1 region, $$\hat R$$ frequencies of CBMEX3 and NSO were not significantly different, but both had significantly greater $$\hat R$$ values than CBCAR5. For the Idh2-Mdh2 region, CBMEX3 was significantly different from NSO. There were significant differences between some paired F families within each population for each chromosome region. No significant differences in response to the two environments were detected in CBMEX3 and NSO for either region in chromosome 1. [ABSTRACT FROM AUTHOR]

The use of several S individuals to represent an S individual permits the use of a Design II mating scheme for plants with only one pistillate flower per plant. Estimates of additive (V) and dominance (V) variance from this mating scheme will be biased upwards, when a small number (10) of individuals of each S line are used. This bias can be computed, and the additive and dominance estimates can be corrected. Of particular interest is the observation that the additive genetic variance contributes to bias in estimates of V. When S plants are non inbred and their selfedprogeny (S lines) are used to represent them in developing families for use in the Design II, $$\hat VA = \hat VA\left( {1 + 1/2m_1 } \right){\text{ and V}}_{\text{D}} {\text{ = V}}_{\text{D}} \left( {{\text{1 + }}\frac{{\text{5}}}{{{\text{4m}}_{\text{2}} }}} \right) + \left( {\frac{1}{{m_2 }} - \frac{1}{{m_1 }}} \right)V_A $$ where m is the number of individuals used to represent an S line in developing half sib-families and m is the number of individuals used to represent the S line in making up full sib-families. For example, in a 3×3 Design II, with about 10 individuals used to represent each S line in each cross, m = 10 and m = 30. When m = m = 1, $$\hat V_A = \left( {1 + 1/2} \right)V_A = \left( {1 + F} \right)V_A $$ and $$\hat V_D = V_D + \frac{5}{4}V_D = \left( {1 + F} \right)^2 V_D $$ [ABSTRACT FROM AUTHOR]

Full and half-sib reciprocal recurrent selection (RRS) were compared algebraically and with computer simulation. The relative performance of the two schemes depended on the selection intensity and the environmental variance. Full-sib RRS was favoured at less intense selection and when the environmental variance was large relative to the total genetic variation. As selection intensity increased its advantage declined. Full-sib RRS enables a breeder to combine the efficient development of new hybrids with population improvement and should be a valuable technique in plant breeding. [ABSTRACT FROM AUTHOR]

Large strain extrusion machining (LSEM) is presented as a method of severe plastic deformation for the creation of bulk nanostructured materials. This method combines inherent advantages afforded by large strain deformation in chip formation by machining, with simultaneous dimensional control of extrusion in a single step of deformation. Bulk nanostructured materials in the form of foils, plates, and bars of controlled dimensions are shown to result by appropriately controlling the geometric parameters of the deformation in large strain extrusion machining. [ABSTRACT FROM AUTHOR]