"Horizontal" gene transfer from a transgenic potato line to a bacterial pathogen (Erwinia chrysanthemi) occurs--if at all--at an extremely low frequency

The frequency of possible "horizontal" gene transfer between a plant and a tightly associated bacterial pathogen was studied in a model system consisting of transgenic Solanum tuberosum, containing a beta-lactamase gene linked to a pBR322 origin of replication, and Erwinia chrysanthemi. This experimental system offers optimal conditions for the detection of possible horizontal gene transfer events, even when they occur at very low frequency. Horizontal gene transfer was not detected under conditions mimicking a "natural" infection. The gradual, stepwise alteration of artificial, positive control conditions to idealized natural conditions, however, allowed the characterization of factors that affected gene transfer, and revealed a gradual decrease of the gene transfer frequency from 6.3 x 10(-2) under optimal control conditions to a calculated 2.0 x 10(-17) under idealized natural conditions. These data, in combination with other published studies, argue that horizontal gene transfer is so rare as to be essentially irrelevant to any realistic assessment of the risk involved in release experiments involving transgenic plants.     

Electric-spark alloying of steel with tungsten-free hard metals

Conclusions A study was made of the ESA of steel with tungsten and tungsten-free TN type hard metals in different units and under different conditions, with and without anode dressing. It has been established that in alloying under finishing conditions the erosion of a dressed TN-20 alloy anode is greater than that of an undressed one; this is due to the formation of stable oxide films on the electrode surfaces. In contrast to this, in treatment under rough conditions the erosion of an undressed anode is greater because the oxide films cannot withstand the higher thermal stress generated during alloying. In ESA with tungsten alloys maximum erosion under both finishing and rough conditions is observed with undressed specimens. This is attributable to the formation of a defective zone promoting periodic brittle disintegration in the course of treatment. Removing the defective zone decreases the erosion of the material. The most favorable conditions for the formation of a reinforced layer are created in the alloying of a dressed cathode surface, and consequently it is best to perform ESA with a specific time of not more than 1 min/cm². Use of treatment conditions with large thermal loads increases the thickness and hardness of the reinforced layer. Reinforcement with TK type alloys sets up a stress which is greater on the specimen surface and extends to a greater depth than the stress generated in alloying with TN type hard metals. Electrodes made of the tungsten-free TN-20 hard metal can be used instead of tungsten alloy electrodes for the ESA of processes V and VI. The resultant reinforced layer is sufficiently thick and continuous.Translated from Poroshkovaya Metallurgiya, No. 11(239), pp. 64–69, November, 1982.     

Mechanical properties of unsintered pressing. i. phenomenological relations for unsintered pressing strength

Theoretical and experimental relationships are considered for the strength of green compacts in relation to various properties of the powder (particle material strength, particle size and shape, and apparent powder density), together with the formation conditions (pressure) and test conditions. The effects of the powder properties, in particular the apparent density, may be examined from simple relationships of the form strength - pressing density with the use of a correction coefficient. One needs to use ideas from the mechanics of compressible media in considering the state of strain in the pressing and the test conditions.     

生产间苯二酚的核心设备锆水解釜的设计制作与应用

根据间苯二酚合成的工艺参数及锆材的耐蚀机理,分析锆材用作间苯二酚水解釜的可行性,参照JB/T4745—2001钛制焊接容器标准设计制作了锆钢复合材水解釜。并根据锆材的特性及合成间苯二酚的工况条件,对设备的环焊缝和接管处均做特殊处理。锆材环焊缝采用Ω型覆板焊接,接管处采用骑坐式结构。该设备在现场使用了1年多时间,证明用锆材制作合成间苯二酚设备,虽然接近锆材使用的临界值,但是仍能通过优化选材、合理设计和制作来满足使用要求。     

Lack of permanent nigrostriatal dopamine deficit following 6-hydroxydopamine injection into the rat striatum. Short communication

OBJECTIVE: Understanding the contributors to physical disability in older adults is an important component of the national health objective of expanding disability-free life by the year 2000. The purpose of this study was to determine the frequency with which older adults attribute their difficulty performing a number of common daily tasks to "old age" and to identify specific conditions and diseases associated with this attribution. Finally we sought to determine the characteristics that might differentiate persons able to attribute their disability to specific conditions from those who cite old age as the etiology of their disability. DESIGN: A cross-sectional, observational, study. SETTING: The Johns Hopkins Functional Status Laboratory. PARTICIPANTS: Two hundred thirty community-dwelling volunteers 60 years of age and older who could stand unassisted for > or = 1 minute and who were without cognitive impairment. MEASUREMENTS: A 1-day evaluation included physical performance evaluations, both performance-based and self-reported function for 27 tasks, and self-report of physician-diagnosed diseases. Those with difficulty in a task and those who denied difficulty but had changed the method of task performance (modification) because of an underlying health or physical condition were identified and asked to name the cause of their difficulty or task modification; options were specific diseases/medical conditions or "old age." The prevalence of "old age" citation as a cause of functional limitation, as well as its associated characteristics and medical conditions, was determined. MAIN RESULTS: Twenty percent of the 230 participants cited "old age" as the cause of their disability in two or more tasks. Tasks for which difficulty was most frequently attributed to "old age" were dressing oneself (31%), walking around the home (25%), walking 1/2 mile (5-6 blocks) (25%), cutting toenails (16%), getting in or out of a bed or chair or out a car (14% each), and ascending/descending stairs (13%). Significantly higher levels of arthritis, heart disease, and hearing loss were reported in persons attributing their disability to "old age" than in those not reporting "old age" as the cause of their disability. We found no differences in age, gender, race, education, or cognitive status for the two groups. However, individuals citing "old age" as the cause of functional decrements walked more slowly than those who cited a specific disease. CONCLUSIONS: These data suggest that a significant proportion of functional decline attributed to "aging" in older adults may be associated with specific conditions. Identifying and reducing the impact of these conditions may prove to be a useful approach to preventing or minimizing functional loss.     

The mismatch negativity to frequency deviant stimuli during natural sleep

Eight subjects spent a single night in the sleep laboratory. Event-related potentials (ERPs) were recorded during the presentation of two auditory "oddball' stimulus conditions in which tonal frequency was manipulated. In the first condition, 1000 Hz "standard' and 2000 Hz "deviant' tones were presented. In the second condition, the deviant tone was reduced to 1050 Hz. In both conditions, deviant probability was 0.2. Stimuli were presented every 600 ms during wakefulness and stages 2, 4, and REM of sleep. A distinctive N1 wave was visible in both stimulus conditions when the subject was awake. The deviant stimuli elicited a "mismatch negativity' (MMN) that inverted in polarity at the mastoid. In REM sleep, an N1 and a MMN were also elicited in both conditions. In the large deviance condition, the MMN had a slightly attenuated amplitude and was shorter in duration while in the small deviant condition, its peak latency was unusually early. Neither the N1 nor the MMN could be recorded in non-REM sleep.     

Effects of noise level and difficulty of task in performing division.

Ss worked division problems for 20 min. in the presence of 98 db.-108 db. of noise while Ss of comparable mean ability in arithmetic worked the problems under conditions of room noise. Under each condition 1 group of Ss worked "easy" problems and another group worked "difficult" problems. Intense noise produced no effect on mean number of problems correctly solved. Variability of performance was significantly greater with easy problems under intense noise conditions than under room-noise conditions, although there was no difference with difficult problems. There was no evidence of a decrement in performance within the 20-min. session attributable to noise level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of the Preparation of Reduced Low-Carbon Iron Powder from Hematite Using the “Frozen Furnace” Experiment

As a rule, the reduction kinetics for hematite in industrial units differs markedly from the process under laboratory conditions. A study is made of the reduction kinetics of hematite concentrate under conditions most closely approximating industrial conditions (in a pilot furnace for annealing powder raw material developed at the Gas Institute of the National Academy of Sciences of Ukraine, and constructed at the Advanced Research Center for Powder Metallurgy and New Materials (Hyderabad, India). The essence of the experiment, called the frozen furnace by us, consists of the fact that at a prescribed instant of time the reducing atmosphere in the furnace is replaced by an inert atmosphere stopping the reduction process and fixing its current state. The kinetic reduction curve is obtained for a freely poured flat dispersed layer of hematatite concentrate. Reduction is separated into three clearly defined periods: quasihomogeneous, diffusion-autocatalytic, and diffusion. The similarity of reduction of a dispersed layer of material and an individual particle is confirmed, and the difference only consists in the geometric and time scales. These studies make it possible to evaluate the role of the scale factor in predicting the reduction of a dispersed layer of material under industrial conditions.     

A record-linkage study on risk factors for cause-specific infant mortality

Infant death certificates were linked with birth certificates for infants born to residents of Tohoku, Tokai and Kyushu regions in 1989 (n = 409, 679, or about one-third of all births in Japan), to examine the effects of variables, as reported on birth certificates, on cause-specific infant mortality. "Certain conditions originating in the perinatal period" and "congenital anomalies" accounted for nearly 90 percent of neonatal deaths, while "congenital anomalies", "injuries and poisoning" and "sudden infant death" were responsible for about 65 percent of postneonatal deaths. Mortality rates for almost all causes of infant deaths, except injuries and poisonings, increased as birth weight decreased not only in the neonatal period but also in the postneonatal period. This suggests that low birth weight places some infants at higher risk of death, and conditions that lead to low birth weight independently contribute to the risk of infant death. Cox's proportional hazards linear model was used to assess the effects of variables on infant mortalities by causes of death. An extremely strong birth weight effect was noted for "certain conditions originating in the perinatal period" and "congenital anomalies". Being a male infant and late order of birth in multiparity were other risk factors for deaths from "congenital anomalies", while being a male infant, resident of Tohoku region and maternal stillbirth experience related to deaths from "certain conditions originating in the perinatal period". Elevated risks of sudden infant death syndrome (SIDS), of which mortality rate in Japan was considerably lower than those in most developed Western countries, i.e. 0.23 per 1,000 live births in 1989, were associated with low birth weight, being a male infant, low maternal age, late order of birth in multiparity and illegitimacy. Low maternal age, late order of birth in multiparity and illegitimacy, also, related significantly to increased risk of infant deaths for "injuries and poisoning". These results suggest the independent contributions of socioeconomic factors to infant mortality, especially postneonatal mortality, from SIDS, "injuries and poisonings".     

A strategic response to the occupational health establishment

The experiences of occupational health and safety "activists" in Canada reveal the limits of achieving reform in working conditions by technical efforts in combination with rank-and-file activation. The author argues that the way union "activists" approach occupational health and safety limits workers in dealing with their actual experiences and understanding about workplace hazards and risks, then discusses the condition for the awakening of their critical consciousness as a basis of acting on hazardous working conditions. The first movement in the way the worker apprehends the work environment is a movement of negation and is the prior condition to a critical and disclosive discourse about workplace hazards. It is the positive side of "No!" and the taking seriously of workers' rights. It is this negation of the negative that holds out the greatest hope for solidarity and a liberatory community in workplaces, since legislated workers' rights as the basis of protection have become a facade. Workers can respond with the power of saying "No!" in solidarity with suffering workers, and then work through appropriate principles, ends, or strategies avoiding entrapment by a "telos" in the first instance. By laying out these "ends" or a strategic paradigm, one introduces a "conversation stopper" for workers and atrophies their activation.     

Determination of the kinetics of size variation of a single pore in a mass of a viscous material with allowance for absorption and desorption

Conclusions The law of pore radius variation r=r() cannot be found without taking into account the functions of concentration distribution of two gases over the thickness of the matrix Ci=C₁(, ) and C₂ = C₂(, ). Because of this, it is proposed that the unknown functions of r, C₁, and C₂ be found by solving the system of three differential equations (3), (A), and (26) at the three initial conditions (8)–(10) and four boundary conditions (19), (20), (27), and (29). Depending on the nature of the matrix material and dissolving gases, the boundary conditions (27) and (29) may become transformed into the conditions (28) and (30). In dealing with a fuller model, including three or more gases dissolving in a matrix, it is necessary to solve a system of four or more equations in accordance with Eqs. (1) and (2). The necessary initial and boundary conditions can always be formulated by analogy with Eqs. (8)–(10), (19), (20), and (27)–(30).Translated from Poroshkovaya Metallurgiya, No. 7(271), pp. 32–36, July, 1985.     

The adaptiveness of self-control: Simulation of foraging mice.

Tobin and Logue (1994) have proposed that interspecific differences in rates of delay discounting are driven by differences in metabolic rates. This "metabolic hypothesis" argues that under conditions of deprivation impulsive animals will out-compete self-controlled animals. The authors report here a series of modeling experiments testing the predictions of Tobin and Logue (1994) using a simulated population of "mice" in which the average meal size, the standard deviation of the meal size, collection risk and maximum delay were parametrically manipulated. The authors found that for all meal size averages and standard deviations self-controlled "mice" out-competed impulsive "mice" and that this advantage was most marked under conditions of deprivation. Conversely, increasing collection risk or maximum delay promoted the dominance of impulsive strategies. These results call into question the "metabolic hypothesis" and suggest that interspecific differences in collection risk may drive differences in rates of delay discounting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of density and test conditions on measured compression and shear strength of cancellous bone from the lumbar vertebrae of ewes

An animal model (the ewe) was used to study mechanical parameters of cancellous bone specimens. Compression and shear tests were conducted on ewe vertebral trabecular bone (L1-L5) from old ewes (mean age: 9 years) under two different conditions: first, at room temperature in air ("standard" test conditions); and secondly, in a physiological saline bath regulated at 37 degrees C. The parameters obtained under "standard" test conditions with a uniaxial compression test were the mean value of the maximum strength (sigma max = 22.3 (7.06) MPa), Young's modulus (E = 1510 (784) MPa), the strain at maximum strength (epsilon sigma max = 3.21 (0.8) percent) and the energy absorbed during the test (W = 0.3 (0.12) MJ.m-3). No significant change was found when the test was carried out in a saline bath at 37 degrees C (p < 0.0005). An original shear test was performed to evaluate the shear strength which was found to vary from 7.5 (4.7) to 14.6 (8.53) MPa under "standard" test conditions depending on the method of calculation. Testing of the specimens in a 37 degrees C physiological saline bath induced a decrease in the shear strength from 32.5 percent (p < 0.0005) to 37.3 percent (p < 0.0001) of those measured under "standard" test conditions. The non-destructive measurement of the Bone Mineral Density (BMD) accounted for up to 73.3 percent of the maximum compressive strength sigma max and 61.5 percent of the maximum shear strength tau max determined in saline solution at 37 degrees C. These results showed that other parameters influencing the mechanical properties of trabecular bone and its structure appeared to be essential.     

Aand B subject-therapists' responses to videotaped schizoid and intropunitive-neurotic prototypes.

Notes the suggestion from research that individuals classified as a's on the whitehorn-betz a-b scale have been more "effective" with schizoid or schizophrenic patient types, while b's have been more "effective" with intropunitive-neurotic patient types. An analogue experiment was conducted testing whether these compatibility conditions involved varying levels of the "therapist-offered conditions" deemed central by client-centered therapists. 20 a and 20 b volunteer undergraduate males responded "helpfully" and "naturally" at 4 points of interruption to videotaped enactments of intropunitive neurotic and schizoid patient prototypes. As hypothesized, the communication of respect and empathic understanding and the response duration of s-therapists was a joint function of their a-b status and the patient with whom they interacted. Alternative explanations of the more "compatible" dyads are discussed. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counselor power base, influence attempt, and behavior change in counseling.

Gave a 30-min individual interview to 48 college males, all of whom described themselves as "procrastinators." The interview explored current and historical difficulties stemming from Ss' procrastination, and ended with an interviewer attempt to influence Ss to take some specific action on the procrastination issue of greatest current concern. 8 experimental conditions were defined by (a) the 2 interviews, (b) "expert" or "referent" roles, and (c) delivery of influence attempt in a manner congruent with the "expert" or "referent" power base. Results show that (a) Ss perceived interviewers as intended, (b) Ss were induced to perform important behaviors outside the interview situation, (c) the expert and referent power bases were not differentially effective in inducing S compliance, and (d) the frequency of differential conformity in the power-congruent vs power-incongruent conditions approached statistical significance. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To what relevance is research relevant?

Considers the distinction between "applicable" and "relevant" research, suggesting that most psychological research is "relevant" in that it is directed only toward issues in which behavior can be described as a function of specifiable (and created or manipulated) conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interpersonal attraction in aversive environments: A problem for the classical conditioning paradigm?

Several studies have found decreased attraction for a stranger rated under aversive conditions, and these studies have been used to support a model that views attraction as a function of generalization of affect. A number of studies, however, have failed to support such a model, not only failing to show decreases in attraction as a function of negative circumstances but often showing the reverse, that is, enhanced attraction under aversive conditions. It is suggested that studies that have supported the affective generalization model may be limited in ecological validity as a function of their use of a "simulated stranger" paradigm and that results from studies in which "real" strangers are rated can be understood within a negative reinforcement model. Original data from a study in which 60 undergraduate females rated both a fellow S and a bogus stranger under conditions of either aversive noise or low-level noise are presented to support such a resolution. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approach and avoidance responses of the hysterical personality to sexual stimuli.

Administered a paired-associates learning task and a visual recognition task to 32 female hysterical personalities and 32 nonhysterical personalities. Both tasks included neutral and sexual material. 1/2 the Ss in each group performed under sexually "seductive" conditions, the other 1/2 under neutral conditions. Results showed that (1) hysterics learned sexual material quickly under neutral conditions but relatively slowly under sexual conditions; (2) hysterics had a relatively low visual recognition threshold for sexual words under neutral conditions and a relatively high threshold under sexual conditions; and (3) these threshold differences were maximized when sexual stimuli referred to the self. It was concluded that the characteristic behavior of the hysteric was consistent with an approach-avoidance conflict involving sexual motives and behavior. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of deviations from temporal expectations on tempo discrimination of isochronous tone sequences

The effect of deviations from temporal expectations on tempo discrimination was studied in 3 experiments using isochronous auditory sequences. Temporal deviations consisted of advancing or delaying the onset of a comparison pattern relative to an "expected" onset, defined by an extension of the periodicity of a preceding standard pattern. An effect of onset condition was most apparent when responses to faster and slower comparison patterns were analyzed separately and onset conditions were mixed. Under these conditions, early onsets produced more "faster" judgments and lower thresholds for tempo increases, and late onsets produced more "slower" judgments and lower thresholds for tempo decreases. In another experiment, pattern tempo had a similar effect: Fast tempos led to lower thresholds for tempo increases and slow tempos led to lower thresholds for tempo decreases. Findings support oscillator-based approaches to time discrimination.     

Two time-dependent responses of chicks to imprinting stimuli.

Analyzed in detail the conditions eliciting approach behavior to the imprinting stimulus in White Leghorn, New Hampshire, and hybrid White Leghorn-New Hampshire chicks. It was found that the approach response to a relatively weak imprinting stimulus could arise by 2 different mechanisms. Some Ss approached the stimulus object within a few min.; others needed a considerably longer stimulation, essentially a conditioning, to elicit the approach response. The 2 mechanisms, which were termed "prompt approach" and "conditioned approach," were distinguished on the basis of the different conditions required for eliciting them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)