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Objectives As the commercial cannabis industry grows, there is an increased need to characterize potentially hazardous workplace exposures and provide training to workers to mitigate these exposures with the goal of reducing accidents and injuries from cannabis cultivation, processing, and manufacturing. Public health and safety stakeholders in Colorado developed a worker-focused training designed to improve hazard awareness, recognition, and controls related to commercial cannabis cultivation. This paper describes the evaluation of this training. Methods The training was a full day, in-person educational experience directed to workers in the cannabis cultivation industry. Training topics included an overview of occupational safety and health hazards, chemical exposures, slip, trips, and falls, repetitive motion, the application of the hierarchy of control including lockout/tagout, machine guarding, personal protective equipment, among others. Evaluation surveys assessed attendee demographics, perceived job hazards, confidence to change workplace practices, knowledge, training relevancy and quality, intent to change behavior, as well as barriers and resources. Results A total of 208 people attended the safety trainings. One hundred and thirty-four participants (64%) completed the pre-training survey and 107 (51%) completed the post-training survey. Respondents provided high ratings for the quality and relevance of the training, with 91.3% of respondents rating the training very good or excellent. Before the training, the attendees listed their most concerning safety and health issues as exposure to pesticides and other chemicals (65.7%), absorbing chemicals through the skin (56.7%), slips, trips, and falls (52.2%), and respiratory hazards (50.7%). After the training, they reported the most concerning hazards to be slips, trips, and fall hazards (65.4%), ergonomic problems (64.5%), and respiratory issues (61.7%). There was a statistically non-significant increase in knowledge scores from 67.1% correct to 76.0% correct. Finally, 88.5% of respondents felt extremely or very confident that they could change their own health and safety practices at work. Conclusions The training successfully reached cannabis employees in cultivation, compliance, and management. Survey respondents felt that the training was of high quality and addressed gaps in their knowledge related to safety and health hazards in the cannabis industry. The workplace safety and health concerns shifted from pre- to post-training. There was a statistically non-significant increase in knowledge. Additional follow-up of training attendees would be beneficial to measure sustained impact of training. [ABSTRACT FROM AUTHOR]

The effects of marijuana use on workplace safety are of concern for public health and workplace safety professionals. Twenty-nine states and the District of Columbia have enacted laws legalizing marijuana at the state level for recreational and/or medical purposes. Employers and safety professionals in states where marijuana use is legal have expressed concerns about potential increases in occupational injuries, such as on-the-job motor vehicle crashes, related to employee impairment. Data published in 2017 by the Colorado Department of Public Health and Environment (CDPHE) showed that more than one in eight adult state residents aged ≥18 years currently used marijuana in 2014 (13.6%) and 2015 (13.4%) (1). To examine current marijuana use by working adults and the industries and occupations in which they are employed, CDPHE analyzed data from the state's Behavioral Risk Factor Surveillance System (BRFSS) regarding current marijuana use (at least 1 day during the preceding 30 days) among 10,169 persons who responded to the current marijuana use question. During 2014 and 2015, 14.6% of these 10,169 Colorado workers reported current marijuana use, with the highest reported prevalence among workers in the Accommodation and Food Services industry (30.1%) and Food Preparation and Serving (32.2%) occupations. Understanding the industries and occupations of adults with reported marijuana use can help direct and maximize impact of public health messaging and potential safety interventions for adults. [ABSTRACT FROM AUTHOR]

Subcutaneous Sweet's syndrome (SS) is a rare variant of classic SS characterized by a neutrophilic infiltrate exclusively or predominantly in the subcutaneous tissue, with minimal or absent dermal involvement. We report the case of a patient with a history of chronic myelogenous leukemia who developed subcutaneous SS. Although it has been described in patients with myelodysplastic syndromes and acute myeloid leukemia, this is the first report, to our knowledge, of this rare entity occurring in the setting of a myeloproliferative disorder. [ABSTRACT FROM AUTHOR]

Laser microdissection is an invaluable tool in medical research that facilitates collecting specific cell populations for molecular analysis. Diversity of research targets (e.g., cancerous and precancerous lesions in clinical and animal research, cell pellets, rodent embryos, etc.) and varied scientific objectives, however, present challenges toward establishing standard laser microdissection protocols. Sample preparation is crucial for quality RNA, DNA and protein retrieval, where it often determines the feasibility of a laser microdissection project. The majority of microdissection studies in clinical and animal model research are conducted on frozen tissues containing native nucleic acids, unmodified by fixation. However, the variable morphological quality of frozen sections from tissues containing fat, collagen or delicate cell structures can limit or prevent successful harvest of the desired cell population via laser dissection. The CryoJane Tape-Transfer System®, a commercial device that improves cryosectioning outcomes on glass slides has been reported superior for slide preparation and isolation of high quality osteocyte RNA (frozen bone) during laser dissection. Considering the reported advantages of CryoJane for laser dissection on glass slides, we asked whether the system could also work with the plastic membrane slides used by UV laser based microdissection instruments, as these are better suited for collection of larger target areas. In an attempt to optimize laser microdissection slide preparation for tissues of different RNA stability and cryosectioning difficulty, we evaluated the CryoJane system for use with both glass (laser capture microdissection) and membrane (laser cutting microdissection) slides. We have established a sample preparation protocol for glass and membrane slides including manual coating of membrane slides with CryoJane solutions, cryosectioning, slide staining and dissection procedure, lysis and RNA extraction that facilitated efficient dissection and high quality RNA retrieval from CryoJane preparations. CryoJane technology therefore has the potential to facilitate standardization of laser microdissection slide preparation from frozen tissues. [ABSTRACT FROM AUTHOR]

American energy policy in the Black Sea region is centered on encouraging the safe and reliable transportation of energy supplies westward from Central Asia and the Caspian Sea. Establishing this east-west corridor will reduce traffic through vulnerable energy chokepoints and break Russia's near-monopolistic control of oil and gas transit routes in the region. Not only will this strategy improve European and Eurasian energy security, it will also reduce Moscow's ability to interfere with the states of the Black and Caspian Sea regions. Greater freedom from Russia will allow these states to move closer to the West, opening the door for political and economic reforms. [ABSTRACT FROM AUTHOR]

Here we demonstrate that fruit from tomato (Lycopersicon esculentum) plants expressing Arabidopsis (Arabidopsis thaliana) H+/cation exchangers (CAX) have more calcium (Ca2+) and prolonged shelf life when compared to controls. Previously, using the prototypical CAX1, it has been demonstrated that, in yeast (Saccharomyces cerevisiae) cells, CAX transporters are activated when the N-terminal autoinhibitory region is deleted, to give an N-terminally truncated CAX (sCAX), or altered through specific manipulations. To continue to understand the diversity of CAX function, we used yeast assays to characterize the putative transport properties of CAX4 and N-terminal variants of CAX4. CAX4 variants can suppress the Ca2+ hypersensitive yeast phenotypes and also appear to be more specific Ca2+ transporters than sCAX1. We then compared the phenotypes of sCAX1- and CAX4-expressing tomato lines. The sCAX1-expressing tomato lines demonstrate increased vacuolar H+/Ca2+ transport, when measured in root tissue, elevated fruit Ca2+ level, and prolonged shelf life but have severe alterations m plant development and morphology, including increased incidence of blossom-end rot. The CAX4-expressing plants demonstrate more modest increases in Ca2+ levels and shelf life but no deleterious effects on plant growth. These findings suggest that CAX expression may fortify plants with Ca2+ and may serve as an alternative to the application of CaCl2 used to extend the shelf life of numerous agriculturally important commodities. However, judicious regulation of CAX transport is required to assure optimal plant growth. [ABSTRACT FROM AUTHOR]

We demonstrate that carrots expressing the Arabidopsis H+/Ca2+ transporter CAX1 (Cation Exchanger 1) contained up to 50% more calcium (Ca) than plants transformed with control vectors. The GAX/-expressing carrots were fertile, and robust plant growth was seen in the majority of the transgenic plants. GAX1-expressing carrots were crossed to a commercial carrot variety to confirm that the increased Ca accumulation was mediated by GAX1-expression, and the increased Ca content was clearly correlated with the transgene. This study suggests that modulation of ion transporters could he an important means of increasing the Ca content of agriculturally important crops. To our knowledge, this study represents the first attempts to use biotechnology to increase the Ca content of an agriculturally important crop. [ABSTRACT FROM AUTHOR]

In the past decade, 49 states have adopted rigorous curriculum standards. This has resulted in a significant impact on special education policy and practice. A research team consisting of 12 doctoral students and a faculty advisor at the College of William and Mary in Williamsburg, Virginia, reviewed published state standards, primary assessment procedures, and provisions related to participation by students with disabilities, to determine answers to six questions: (a) Have states adopted standards assessment criteria? (b) Are states using performance rewards and sanctions to motivate educators and students? (c) Do states require all students with disabilities to participate in the state assessment process? (d) Have states developed policies regarding testing accommodations for students with disabilities? (e) Do states link assessment performance to high school graduation? (f) How are states approaching alternate assessments? Research across states found differences in the ways in which assessment issues are being addressed and the potential impact that these policies will have on educational opportunities for students with disabilities. [ABSTRACT FROM PUBLISHER]

Data from four studies of adults are used to address the relationship between expectancies for control of one's health (an outcome) and preference for control of health care (a process). The former is operationalized by the use of the Multidimensional Health Locus of Control (MHLC) Scales; the latter by the B and I subscales of the Krantz Health Opinion Survey (KHOS). Descriptive data from the four studies are presented. Significant correlations exist between the B subscale and the PHLC and IHLC scales. Factor analysis of datafrom three of the studies reveals that, along with selected items from other scales, all of the items from both the PHLC scale and the B subscale load on the first factor. Both theoretical and methodological reasons for these findings are discussed. [ABSTRACT FROM PUBLISHER]

Proteins obtained from seedling shoots and floral meristems of Sorghum bicolor (L.) Moench cv. NK 1210 induced mycelial growth in the smut fungus, Sporisorium reilianum in vitro. Proteins precipitated with trichloroacetic acid and ammonium sulfate were equally effective as inducers, although there were minor variations in the pattern of mycelial growth. Hydrolysis of the protein fraction with the proteolytic enzyme pronase E resulted in considerable reduction in the proteins' ability to induce mycelial growth. Digestion of the protein fraction with driselase, resulted in a slight enhancement of biological activity. The results suggest that amino sugar moieties in glycoproteins may act as inducers of mycelial growth in Sporisorium reilianum. [ABSTRACT FROM AUTHOR]

Sporisorium reilianum, the fungus that causes sorghum head smut, was grown with sucrose, lactose, trehalose or raffinose in liquid suspension or on a solid medium. Liquid culture media were analyzed for hydrolysis products of these carbohydrates to determine extracellular enzyme activity of the fungus. Increased amounts of glucose and fructose in the culture medium of S. reilianum grown with sucrose or raffinose indicated that invertase (β-fructofuranosidase, 3.2.1.26) activity was present. No evidence of extracellular galactosidase or trehalase activity was found. Enhanced sporidial colony formation on carbohydrates that can be hydrolyzed to hexoses, and specific forms of mycelial growth on lactose, trehalose or on a carbohydrate-deficient medium might suggest that mycelial growth is a way of foraging for food sources. However, the rapid and profuse mycelial growth on the host cell wall glycoprotein appears to be in response to abundant food supply (probably of a different type). Therefore availability of different kinds of carbon sources in the environment of the growing fungus might determine dimorphism and associated pathogenesis by S. reilianum. [ABSTRACT FROM AUTHOR]

Three monoclonal antibodies (MAb)-were prepared against a cell surface antigen which cross-react between Streptotycoccus muatans (serotypes c, e and f) and Streptococcus sobrinus (serotypes d and g). Two of the MAb also recognise a determinant on the surface of Streptotycoccus muatans(serotype a). The common antigen shared between S. mutans and S. sobrinus was demonstrated by Western blotting to be about 200 kD in size. This antigen is shared not only by the cell surfaces of serotypes a, c, d, e, f and g, but also by the major cell surface antigen of S. mutans of 185 kD. These MAb identify all but one mutans type of streptococci and can be utilised as analytical reagents. [ABSTRACT FROM AUTHOR]

This paper establishes that the isolated shoot meristem of monocotyledons can be infected and transformed using Agrobacterium. Since this explant from nearly any cereal cultivar can rapidly regenerate into a plant, using this explant effectively eliminates the genotype regeneration restrictions to cereal crop transformation allowing direct transformation of elite germplasm. Shoot apices of Oryza sativa L. Tropical Japonica, cv. Maybelle were explants used for cocultivation, and gene transfer was accomplished using Agrobacterium containing plasmids for the bar gene expression driven by the CaMV 35S promoter or by the rice actin 1 promoter. Experiments to determine the survival rates of isolated shoot apices on media containing the herbicide, glufosinate-ammonium (PPT), established that no shoot apices survived on 0.5 or 1.0 mg/l PPT. After shoot apices were cocultivated with Agrobacterium, 2.8% (overall 20 out of 721 shoot apices) survived on 0.5 mg/l PPT. Results demonstrated that the use of the actin 1 promoter-based expression vector and an extra-wounding treatment of the meristematic cells appeared to be most effective in promoting transformation. Integration, expression and transmission of the transferred foreign genes in primary, R1 and R2 generation plants were confirmed by molecular analyses and herbicide application tests. A germination test of R2 progeny from one of the transgenic plants (R1) established a phenotype segregation ratio showing a non-Mendelian inheritance pattern. Inactivation of the transferred foreign gene in R2 progeny appeared to result from transgene methylation. [ABSTRACT FROM AUTHOR]

No abstract available for this article. [ABSTRACT FROM PUBLISHER]

No abstract available for this article. [ABSTRACT FROM PUBLISHER]

Selectable marker genes play an important role in plant transformation. The level of selection pressure is generally established by generating a kill curve for the selectable marker. In most cases, the lowest concentration which kills all explants is used. This study examined two selectable marker genes, phosphinothricin acetyl transferase (PAT) and hygromycin phosphotransferase (HPT), in transformation of tobacco leaf disks. Experiments to determine the lethal level of the herbicide, glufosinate-ammonium (phosphinothricin) (PPT) using a leaf-disk regeneration assay established that no shoots regenerated at 2 to 4 mg PPT per 1. Likewise with the antibiotic, hygromycin (HYG), no plants regenerated at 50 mg hygromycin per 1. In contrast, after cocultivation of the leaf disks with Agrobacterium tumefaciens containing either the PAT or HPT gene in combination with a Bt gene for insect resistance, plants were successfully regenerated from leaf disks at 2 to 4 mg PPT per 1 and 50 mg hygromycin per 1. However, most plants regenerated at 2 and 3 mg PPT per 1 were found to be nontransformed (95–100% escapes) by i) Southern-blot analysis, ii) herbicide application test, and iii) insect feeding bioassay. On the other hand, plants that regenerated on 50 mg hygromycin per 1 and 4 mg PPT per 1 were transgenic as determined by Southern analysis, leaf assay for PPT or HYG resistance, and death of tobacco budworms feeding on these leaves. This study showed a significant level of cross-protection and/or transient expression of the PAT selectable marker gene allowing escapes (95–100%) at selection levels of 2 and 3 mg PPT per 1 which completely kill controls. On the other hand, the HPT gene at 50 mg is efficient in selecting for T-DNA integration. [ABSTRACT FROM AUTHOR]

Arachis hypogaea L. peanut, has been a difficult species to manipulate in tissue culture. Lack of a reliable and quick regeneration method for peanuts has proven to be one of the hindrances in the application of transformation protocols to the crop. A protocol to initiate shoot apex elongation and rooting of these shoots is described. This protocol was successful with two peanut cultivars. Shoot apices were isolated from germinated seedlings and placed on Murashige and Skoog salts containing N-benzyladenine for shoot initiation. Once shoot elongation occurred, the explant was transferred to a rooting medium containing Murashige and Skoog salts and only one plant growth regulator, α-naphthalene acetic acid. In as few as 3 weeks, the explants began to root and could be transferred to soil. Forty-five percent of explants isolated from germinating peanut seeds would root on this medium. Elongation and rooting of the shoot apices were not hindered by the addition of an antibiotic to the medium, indicating that the regeneration method could be useful in Agrobacterium tume-faciens-mediated transformation protocols. [ABSTRACT FROM AUTHOR]

A tissue culture method was developed for the eradication of three important potato viruses, PVX, PVY, and PVS, from the Russet Norkotah variety and two of its strains (TXNS 112 and TXNS 278). The method combined the use of liquid medium, thermotherapy, and chemotherapy. Initially, virus-free plants were inoculated with PVX, PVY, and PVS and, after 10 d, tested quantitatively for virus titer by ELISA to determine the initial virus concentration. The apical tip and the roots were removed from the inoculated plants, and only stem sections from inoculated plants were cultured in liquid medium containing MS inorganic salts, vitamins, and ribavirin (40 µ M or 80 µ M). After 5 d, half of the plants were subjected to thermotherapy and half were kept at room temperature. At 6 wk, the uppermost node (5-7 mm) was removed and recultured, and plants were tested then and again after 6 wk using ELISA to identify the virus-free plants. Ribavirin alone eradicated the viruses from some plants; however, more virus-free plants were obtained when the treatments included heat. Additionally, the in vitro culture technique using liquid medium promoted rapid lateral shoot elongation and resulted in significantly faster plant production. Also this approach, which required less skilled labor, produced more plants than the meristem culture method for virus eradication. A detailed procedure for elimination of multiple viruses is described. This procedure resulted in production of more than 10% virus-free plants. [ABSTRACT FROM AUTHOR]

A solid-phase radioimmunoassay was developed to treasure serum IgG antibodies to a purified protein antigen I/II prepared from Streptococcus mutans. The assay was specific to this antigen and significant binding of 125I-radiolabelled antiserum was found only in sera from rhesus monkeys immunized with the antigen I/II but not in sham-immunized monkeys or those immunized with streptococcal antigen III. A very significant correlation was found in serum IgG antibodies tested by the radioimmunoassay and an immunofluorescent technique ( r = 0.88, P < 0001), The sensitivity of the double-layer radioimmunoassay was increased 10 times by the addition of a third antibody layer and this enabled gingival crevicular fluid antibodies to be measured. Comparison of paired samples of serum and crevicular fluid revealed a very significant correlation between IgG antibodies to streptococcal antigen I/II in the two fluids (P <0.001). These findings suggest that serum antibodies can reach the tooth surface via gingival crevicular fluid. [ABSTRACT FROM AUTHOR]

Histologic examination of shoot-tip explants, 1 wk after culture initiation on Murashige and Skoog medium with 2.5 mg/liter 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.05 mg/liter kinetin, reveals active meristematic centers inside cultured tissue. Clusters of cells in these meristematic centers exhibit remarkable resemblance to the initial three divisions in the zygotic embryo. Several such meristematic groups of cells are observed in the cultured explant at this stage. Embryogenesis is obviously initiated very early in this tissue in the presence of 2,4-D. A well-defined, white globular embryogenic callus develops in culture in about 4 wk, and it consists of clusters of embryoids with large cells characterized by thick cell walls, numerous lipoidal vesicles, and localized areas of carbohydrate storage. These cells resemble the scutellar tissue of the embryo. However, there are cells within this tissue that themselves appear embryogenic. They undergo cell division giving rise to small clusters of cells. As long as 2,4-D is present in the medium, the cells apparently retain the capacity to proliferate and to produce more cells capable of embryogenesis. Embryogenesis seems to occur via two processes, initiation of somatic embryos early in culture and secondary embryogensis from the scutellar tissue that forms in vitro. [ABSTRACT FROM AUTHOR]

Shoot tip cultures from 2- to 3-d-old seedlings of Sorghum bicolor (L.) Moench cv. IS3620C develop highly embryogenic callus from which plants can be regenerated when transferred to plant growth regulator-free medium. Isolated shoot tips were cultured on Murashige and Skoog medium supplemented with 2.5 mg/liter 2,4-dichloro-phenoxyacetic acid and 0.05 mg/liter kinetin. Purple pigmentation characteristic of sorghum cultures on growth regulator-free medium is virtually eliminated with the shoot tip culture. Embryogenic callus is white and hard with an undulating appearance but can be separated into multiple bipolar structures by application of gentle pressure. The well-developed embryos have a cup-shaped scutellum. These germinate like zygotic embryos and develop root-shoot axis. Lack of vascular connections to the parent tissue and the synchronous development of the plumule and radicle suggest that these embryos may be of unicellular origin. In contrast, when the entire seedling serves as the explant, all meristematic centers in the shoot, including the coleoptile sheath close to the apical meristem respond to plant growth regulators in the medium by callus formation. Upon subsequent reculture onto growth regulator-free medium several modes of development occur. The differential response of these tissues to identical culture conditions indicate the presence of different population of cells that respond differently to exogenous plant growth regulators. [ABSTRACT FROM AUTHOR]

Maintainable, highly embryogenic suspension cultures of a wild relative of cotton ( Gossypium klotzschianum Anderss.) have been obtained. Callus with no apparent organization was used to establish the liquid culture. Callus growth conditions as well as suspension medium composition were optimized. A visual selection scheme was beneficial for the maintenance of the embryogenic suspension. These liquid cultures have been maintained for over 10 mo. with no loss in embryogenic capacity. The somatic embryos developed after transfer of the embryogenic tissues to a hormone-free liquid medium. [ABSTRACT FROM AUTHOR]

A method of clonal propagation via somatic embryogenesis of date palm, cultivar Barhee, which has potential for large scale commercial application as well as for developmental studies on embryos is described. Cultures were initiated from shoot tip and immature inflorescence explants, both of which were capable of development into embryogenic callus. When the embryogenic callus was cultured in liquid suspension on a rotary shaker, hundreds of embryos developed from milligram quantities of callus in a fairly synchronous manner. Scanning electron microscopy showed globular, heart-shaped and torpedo-shaped embryos. Green leaves emerged from a white cotyledonary sheath. [ABSTRACT FROM AUTHOR]

A method of regenerating cotton plants from the shoot apical meristem of seedlings was developed for use with particle gun and Agrobacterium-mediated transformation. This method was developed to circumvent the problems of genotype restriction and chromosomal damage frequently encountered in cotton regeneration in tissue culture through somatic embryogenesis. In this procedure, the cells of the shoot meristem are targeted for transformation. Normal and fertile plants of Gossypium barbadense Pima S-6, and 19 cultivars of G. hirsutum were regenerated using this method. Shoot regeneration from these tissues was direct and relatively rapid. A MS based, hormone-free medium could be used with all the varieties tested. [ABSTRACT FROM AUTHOR]

Embryogenesis and plant regeneration of Texas and international rice, Oryza saliva (L.), varieties (both indica and japonica types) were induced in culture on a regime consisting of the use of ABA or BAP in the subculture medium and small (10 mg) callus pieces on the regeneration medium. Ten 10 mg callus pieces on regeneration medium resulted in a 2- to 10-fold increase in plant regeneration over single 100 mg pieces. Plant regeneration of Texas rice cultivars (Lemont, Rico I, Rexmont and Skybonnet) and Taipei 309 was enhanced by the use of ABA in the subculture medium with a 2-fold and a 3- to 10-fold increase in plant regeneration with 2.6 mgL and 26 mgL ABA in the subculture media, respectively. Regeneration of plants from callus of IR36 and IR64 was not enhanced by ABA but by the use of BAP and Trp in the subculture medium or by 2,4-D alone. The subculture medium containing BAP and Trp produced a 5-fold increase in plant regeneration rate from IR64 callus and was equal to subculture medium containing only 2,4-D for IR36 callus. Both Lemont and IR36 were previously reported to be difficult to regenerate or non-regenerative, however, the use of ABA or BAP in the subculture medium, small callus pieces and visual selection of embryogenic callus allowed the regeneration of up to 20 and 22 plants from 100 mg of Lemont and IR36 callus, respectively. [ABSTRACT FROM AUTHOR]

Presents commentaries on several case studies of the response of well- and poorly-adjusted families to the mother's chronic illness. Factors that affect adjustment to chronic illness; Comparison on the responses of the families; Limitations of the study.

Deals with a study which examined whether allowing cancer chemotherapy patients to choose their antiemetic regimen would reduce both physical and emotional distress and whether the provision of choice affected patients differently depending on their degree of desire for control (DFC). Measures of perceived control which were administered; Levels of DFC; Implications for practitioners; Commentaries on the research.

Comments on several articles presented in the 1982 WCHEN symposium concerning the use of data in testing multivariate theoretical models. Application of causal modeling methodology in testing theoretical models; Issues in the professional socialization of nurses; Benefits of using the techniques of causal modeling.

We have utilized the antigen-binding function of a subset of T8+ cells to remove these cells in vitro from human peripheral blood mononuclear cells. This was carried out by treating the cells with streptococcal antigen (SA), monoclonal anti-SA antibody and complement. The concentration of SA binding to T8+ cells differs with the HLA-DR type of the cells; 1 ng SA binds to DRw6+ cells and elicits T helper activity, whereas 1000 ng SA elicits T suppressor activity, in an assay for antibody-forming cells. After depletion of the antigen-binding cells by the SA-specific complement-dependent killing technique. the helper function of the DRw6+ cells was lost but suppression was elicited not only by 1000 ng but also by 1 ng SA. Similarly, DRw+ cells which bind 1000 ng SA to elicit helper activity and 1 ng to elicit suppression, when depleted of the SA-binding cells, resulted in loss of helper activity but again, suppression could be elicited by both 1000 and 1 ng SA. We suggest that treatment of mononuclear cells with antigen. the specific antibody and complement removes the T8+ antigen-binding cells which present antigen to I helper cells and results in the loss of helper function. Suppressor function is however, not only retained with the original concentration of SA but also expressed with that required to elicit helper function in the untreated cells. These findings are consistent with our hypothesis that the antigen-binding and presenting T8+ cells also function as contrasuppressor cells. Thus, the T8+ subset of cells have a dual function, to present antigen and to activate T helper cell function, and to prevent suppressor cells from inhibiting the helper cells. [ABSTRACT FROM AUTHOR]

β-glucuronidase (GUS) can be assayed in the spent media of plant tissues transformed with some GUS gene fusions (Jefferson, 1988). This approach is based on the presence of GUS in the media of transformed plant tissues expressing the gene and can be used to monitor the progress of transformation without destruction of the tissue under study. [ABSTRACT FROM AUTHOR]

Presents a reaction to the article "Hispanic Adolescent Farmworkers' Perceptions Associated With Pesticide Exposure," by Mary K. Salazar et al. Evaluation of the research methods employed; Steps nurses must do in the wake of the authors' research findings; Political of nurses' associations.

Somatic embryoids differentiated in suspension cultures of G. klotzschianum after 3-4 weeks of culture in a liquid medium containing glutamine (optimally, 10-15 mM). Embryogenesis occurred after a preculture of callus on a medium containing 10 mg/l of the cytokinin, 2iP. The embryoids had meristematic regions, a well formed epidermis, and formed roots and vestigial leaves. Asparagine was much less effective than glutamine in promoting embryoid differentiation. The presence of 2,4-D in the medium resulted in increased vigor of the suspension cultures and subsequently in the formation of many embryoids, but does not seem to be necessary for somatic embryogenesis in cotton. [ABSTRACT FROM AUTHOR]

Stem and petiole sections from a diploid species of cotton ( Gossypium klotzschianum Anderss.) were longitudinally sliced and placed on a callus induction medium. Explants with the cut surface in contact with the medium either browned or produced a slow growing red callus which could not be subcultured. Explants oriented with the epidermis in contact with the medium produced a rapidly growing, friable, green callus which could be subcultured biweekly and has been maintained for 12 months. Globular and torpedo embryos were obtained 2 weeks after transfer of the callus to a liquid medium containing the auxin, 2,4-dichlorophenoxyacetic acid. Following subculture to an auxin-free medium, the embryos underwent additional development but plantlets were not obtained. Attempts to consistently regenerate plants from embryos are currently under way. [ABSTRACT FROM AUTHOR]

Conventional propagation of amaryllis, Hippeastrum Herbert sp. hybrids by bulb offsets is slow, seasonal, and variable; additionally, some amaryllis hybrids do not produce many offsets. From seed, it takes approximately 2 yr to flower. Micropropagation of Zephyranthes L. sp. bulbs has challenges related to contamination of stage I cultures as well as genotype differences in culture media requirements. There are literature reports on in vitro propagation of both genera; however, the application of these reports to new cultivars leaves unanswered questions regarding surface disinfestation, explant, nutrient media, and multiplication rates. Surface disinfestation of container-grown Hippeastrum spp. hybrid cv. San Antonio Rose bulbs resulted in contamination rates of 20 to 100% in spite of various treatments, some of which killed the explant. Twin scale explants of San Antonio Rose bulbs responded on a Murashige and Skoog salt medium with 2 mg naphthalene acetic acid per 1, and transfer to soil was not a problem. In contrast, aseptically germinated seed of Zephyranthes sp. served as a suitable source of clean bulb tissue. [ABSTRACT FROM AUTHOR]

Two cross-sectional studies explored the relationship between age and individuals' desire for control both on a general day-to-day level and as patients in health care situations. The relationship between age and expectancies for control over health also was examined. In Study 1, questionnaire surveys completed by 246 community adults ranging in age from 19 to 77 indicated that for health-specific measures at older ages, belief in internal control and desire for control are lower, and belief in control by powerful others is higher. In contrast, no significant differences in general desires for control were found across age groups. In Study 2, expectancies and desire for control in relation to the health of 350 patients about to undergo barium enemas, chemotherapy, or surgery were measured. Older adults reported a lower desire for control of their health care and a greater belief in the ability of powerful others to control their health than did younger adults. The replication of these age differences across samples differing in several respects, including education and health status, suggests that this is a highly reliable finding [ABSTRACT FROM PUBLISHER]