RNA Interference for Functional Genomics and Improvement of Cotton (Gossypium sp.).

RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium sp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function and biological roles of many key cotton genes involved in fiber development, fertility and somatic embryogenesis, resistance to important biotic and abiotic stresses, and oil and seed quality improvements as well as the key agronomic traits including yield and maturity. Here, we have comparatively reviewed seminal research efforts in previously used antisense approaches and currently applied breakthrough RNAi studies in cotton, analyzing developed RNAi methodologies, achievements, limitations, and future needs in functional characterizations of cotton genes. We also highlighted needed efforts in the development of RNAi-based cotton cultivars, and their safety and risk assessment, small and large-scale field trials, and commercialization.

Endoscopic plantar fasciotomy: a minimally traumatic procedure for chronic plantar fasciitis.

Endoscopic plantar fasciotomy (EPF) is a minimally invasive and minimally traumatic surgical treatment for the common problem of chronic plantar fasciitis. This procedure is indicated only for the release of the proximal medial aspect of the fascia in cases that do not respond to aggressive conservative, nonsurgical treatment. In the literature, an overall 87% success rate has been reported in 1228 procedures, in addition to an 83% success rate reported by Burke at the Northwest Podiatric Foundation Surgical Seminar in January 2000. The author's personal experience with 41 procedures over 5 years is consistent with an overall average success of 90%. EPF complications are reduced in comparison with traditional open procedures and can be avoided in many cases when identified early and treated properly. EPF is recommended as the procedure of choice when conservative treatment measures have been exhausted.

Osteonecrosis secondary to internal fixation.

Allergies to metals as a cause of failure of joint prostheses has historically been a controversial issue. Loosening of a prosthesis may be due to trauma, infection of the surrounding area, or a faulty implantation of the device. However, cases of loosening of the device do occur without any history of the above criteria. This leads one to consider other explanations for this phenomenon, such as sensitivity of the tissues to one of the metals in the implant. The following presentation demonstrates that metal allergies are a surgical concern when considering joint prostheses, or internal fixation.

Near fatal systemic toxicity from local injection of podophyllin for pedal verrucae treatment.

An extremely rare case of systemic podophyllin toxicity from local injection is presented with a review of the literature. There is only one other known similar case reported in the medical literature world wide. Clinical and pathologic findings will be discussed.

A comparative analysis of conservative versus surgical treatment of Morton's neuroma.

The authors present a study of the treatment of Morton's neuroma. Sixty patients, involving 65 feet treated, were studied. Conservative treatments were compared to surgical excision of the neuroma. As a result of the findings in this study, the authors recommend surgical excision as the initial treatment of choice.

A modified method for human bone marrow filtration prior to bone marrow transplantation.

A technique is described for filtering harvested bone marrow using disposable materials, namely a 4 x 4 inch piece of sterile gauze that is gently packed into the barrel of a 60-ml plastic disposable syringe, which is connected directly to a blood collection bag. The filtration of marrow directly into the collection bag eliminates additional filtration steps and therefore may potentially reduce the incidence of inadvertent microbial contamination. In this study we describe this filtering technique and compare it to the method described by Thomas and Storb. Numbers of granulopoietic progenitors (CFU-GM) and erythropoietic progenitors (BFU-E), total white cell counts, percentage of cells positive for the CD3 (OKT3) lymphocyte surface membrane marker, and volume changes were studied following filtration by each method. The two techniques were shown to be comparable in terms of these parameters. Furthermore, when compared with historical controls, this method resulted in a reduced incidence of microbial contamination compared to filtration using successive stainless steel screens.

Immunologic, morphologic and chromosomal characterization of a cell line (TC78) established from a child with acute lymphoblastic leukemia.

We characterized a cell line established from bone marrow cells from a child with acute lymphoblastic leukemia. This cell line, TC78, had lymphoblastic morphology and was cytoplasmic peroxidase and esterase negative. The cells did not have T- or B-cell properties such as E- or EAC-rosette forming ability, reactivity with monoclonal T-cell or B2 antibodies, or immunoglobulin synthesis. We concluded that TC78 was a pre-pre B-cell line based on the following monoclonal antibody staining pattern: BA-1+, BA-2+, cALLa+, Ia+, 2H7+ and OKB2+. Growth in 'Dickie' culture and reactivity with 1G10 myeloid antibody suggested coexpression of lymphoid and myeloid characteristics. However, 1G10 expression proved dependent on culture conditions, illustrating one caveat in application of monoclonal antibodies in lineage determination.

Stimulus control of schedule-induced activity in pigeons during multiple schedules.

Stimulus control of schedule-induced general activity was demonstrated with pigeons using multiple schedules of response-independent food delivery. In Experiment 1, the introduction of food during a multiple variable-time 30-second variable-time 30-second schedule produced a tenfold increase in activity above the no-food baseline. Each pigeon developed stable differential activity rates during the components (correlated with red and green lights) of a multiple variable-time 30-second extinction schedule. Lengthening the extinction component from 1 to 7 minutes increased the rate differences and produced a reliable pattern of responding during S- (the stimulus correlated with extinction): Activity rate was high immediately following the change from S+ (the stimulus correlated with variable-time 30-second) to S-, then decreased abruptly and remained low throughout the middle of the interval, and subsequently showed a positively accelerated increase until the stimulus changed to S+. In Experiment 2, three pigeons were exposed to a mixed variable-time extinction schedule prior to a multiple variable-time extinction schedule. Auditory rather than visual stimuli were used to determine the generality of Experiment 1 results. The multiple- versus mixed-schedule results indicated that stimulus control of activity occurred for two of the birds, but rate differences between S+ and S- were much less than those demonstrated with visual stimuli. A direct comparison of visual and auditory stimulus control in Experiment 3 supported this conclusion. These parallels between the stimulus control of reinforced responding and that of schedule-induced activity suggest that the stimulus control of induced activity may be a factor in operant stimulus control.

Fast acquisition of cooperation and trust: A two-stage view of trusting behavior.

Trustful behavior was defined in terms of the consecutive numbers of matching-to-sample problems worth money that each subject worked during sessions that ended in an equitable distribution. Two stages of acquisition are inherent in this definition; the first stage requires acquisition of an equitable method of distributing reinforcers (cooperation) to show that the within-session deviations (trust) from equity that develop during the second stage are temporary and are not part of an inequitable method of distributing reinforcers. Previous research has indicated that a contingency to trust is necessary to override the aversiveness of the inequity inherent in trusting and to produce consistent and maximal trust (half of the problems worked consecutively by each subject). The present experiment examined such a contingency. The trust contingency was an increased requirement for changing the direction of problem allocation. Only the subject who had been allocated a problem could change that allocation, by pulling a lever 45 or more times. On the other hand, no separate responses were required to allow the person who worked the last problem to also work the next one (passive trust). Hence, giving a problem was the only way to increase the distribution of problems to the other person and hence prevent oneself from receiving all of the reinforcers. All eight pairs of subjects cooperated from the outset. Trusting behavior developed for all four pairs exposed to the contingency to trust and expanded to maximal levels by the second session for three of the four pairs.

Analysis of discriminative control by social behavioral stimuli.

Visual discriminative control of the behavior of one rat by the behavior of another was studied in a two-compartment chamber. Each rat's compartment had a food cup and two response keys arranged vertically next to the clear partition that separated the two rats. Illumination of the leader's key lights signaled a "search" period when a response by the leader on the unsignaled and randomly selected correct key for that trial illuminated the follower's keys. Then, a response by the follower on the corresponding key was reinforced, or a response on the incorrect key terminated the trial without reinforcement. Accuracy of following the leader increased to 85% within 15 sessions. Blocking the view of the leader reduced accuracy but not to chance levels. Apparent control by visual behavioral stimuli was also affected by auditory stimuli and a correction procedure. When white noise eliminated auditory cues, social learning was not acquired as fast nor as completely. A reductionistic position holds that behavioral stimuli are the same as nonsocial stimuli; however, that does not mean that they do not require any separate treatment. Behavioral stimuli are usually more variable than nonsocial stimuli, and further study is required to disentangle behavioral and nonsocial contributions to the stimulus control of social interactions.

Toward a science of history.

The scientific status of History was compared to other sciences in the critical areas event selection, investigative operations, and theory construction. First, in terms of events studied, history is regarded as a quasi-scientific study of past events. However, viewed from the science of behavior's perspective of what historians actually do, history becomes a study of current records. As a study of currently existing records, not the non-existent past, history has potential to become a science. Second, like other scientists, historians may undertake manipulative investigations: they can locate the presence and absence of a condition in records and thereby determine its relation to other recorded phenomena. A limitation has been the lack of quantification that results from emphasis on the uniqueness of things rather than on their communality. Scientific training would facilitate viewing similar things as instances of a larger class that could be counted. Another limitation that cannot be easily overcome is the inability to produce raw data. This limitation has created problems in theoretical practices, the third area of comparison, because theoretical constructions have frequently been substituted for missing data. This problem too could be reduced through scientific training, particularly in other behavior sciences. An authentic science of history is possible.

Using miniature osmotic infusion pumps to maintain tritiated thymidine exposure to cells in culture.

To provide a constant level of tracer doses of tritiated thymidine to cultured cells during continuous infusion, miniature osmotic infusion pumps were used to provide replacement thymidine. By determining the loss of isotope from the media during nonreplacement, the rate of constant infusion replacement to maintain thymidine levels was calculated. The replacement rates were similar for the three cell lines examined and allowed a standard osmotic pump infusion.

The basic-applied continuum and the possible evolution of human operant social and verbal research.

Human operant research is typically viewed as fitting somewhere between the end points of a basic-to-applied continuum. Viewed in this way, the major role of human operant research is to determine the conditions under which principles discovered with animals also hold with humans. Relative to the basic and applied end points, which have defined the major journals and graduate training programs in Behavior Analysis, the human operant area has not been strong since the late 1950's when a scientifically based application was only an exciting possibility. However, application quickly became a reality and to some extent it replaced the major role of human operant research. After about 15 years of focusing on the basic and applied end points, an increasing number of behavior analysts are concerned about the large content of psychology (e.g., social and verbal behavior) between the end points and the continued growth of Behavior Analysis. Basic research in social and verbal behavior should ordinarily begin with the human instead of a lower animal, because the human is the most qualified and prepared subject in the sense that most complex social and verbal behaviors are more accessible in humans. This new role for basic human research of initiating rather than only replicating, could result in a rebuilding of the "bridge" between basic and applied, and contribute to the growth of Behavior Analysis in terms of extensions to new content areas, methods, and the followers it would reach in these areas.

Acquisition and maintenance of trusting behavior.

This study determined whether a two-person exchange situation contained natural contingencies for trusting behavior or whether external contingencies were necessary. Pairs of college students worked matching-to-sample problems for money. On each trial there was one problem and the subjects determined which of them would solve it. Trusting behavior was defined as an increase in the number of consecutive problems each subject allowed his partner to work during sessions that also ended with an equitable distribution. Simply, trust was a temporary deviation from equity. A subject could give the problem to the other person (cooperate), or not respond and let the other person take the problem (share). Other possibilities were for both subjects to try to take the problem (complete), or for neither subject to respond and thereby let the person who worked the last problem also work the next one (passive trust). When only four lever pulls were required to distribute a problem (no external contingencies to reach either equity or trust) subjects reached equity, but only minimal trust (strict alternation of single problems) developed in 18 sessions. When 30 or 60 lever pulls were required to distribute a problem (smaller response requirement for passive trust and therefore a contingency for trust), trusting behavior developed after a few sessions (fixed ratio 30) or after several trials of the first session (fixed ratio 60) and it ordinarily expanded gradually to 10 to 15 consecutive problems through passive trust. The aversiveness of the inequity involved in trusting appears to necessitate a contingency for acquisition. Once trust develops, however, this aversiveness is reduced as subjects learn the inequity is only temporary (e.g., once trust was acquired at fixed ratio 60 it was maintained at fixed ratio 4, which would not initially produce it), and the direction of the inequity appears to become of questionable importance (e.g., being behind was alternated over rather than within sessions and usually not in a systematic manner).

Some relations between classically conditioned aggression and conditioned suppression in squirrel monkeys.

During three experiments with squirrel monkeys, stimulus and shock pairings were given in the presence of a bite tube. Experiments 1 and 2 used a conditioned-suppression procedure in which bar pressing was reinforced with food. A transparent shield prevented biting of the bar. When the stimulus was paired with shock, bar pressing decreased (conditioned suppression) and tube biting increased during the stimulus (classically conditioned aggression). When the bite tube was removed on alternate sessions in Experiment 2, there was more suppression when the tube was present, thus suggesting that biting competed with bar pressing. However, this simple competing-response interpretation was complicated by the findings of Experiment 3 where, with naive monkeys, bar pressing was never reinforced with food, yet bar pressing was induced during the stimulus and was highest when the bite tube was absent. The fact that stimulus-induced bar pressing developed inciated that bar pressing in conditioned-suppression procedures, suppressed or not, may be maintained by two types of control--the food reinforcer and induced CS control. The higher rate of induced bar pressing during the stimulus with the bite tube absent confounds a simple competing response interpretation of conditioned suppression. It suggests that shock-induced responses during conditioned suppression could be both contributing to and competing with responding maintained by food, with the net effect depending on specific but ill-defined features of the situation.

Operant and nonoperant vocal responding in the mynah: Complex schedule control and deprivation-induced responding.

Several recent studies have been concerned with operant responses that are also affected by nonoperant factors, (e.g., biological constraints, innate behavior patterns, respondent processes). The major reason for studying mynah vocal responding concerned the special relation of avian vocalizations to nonoperant emotional and reflexive systems. The research strategy was to evaluate operant and nonoperant control by comparing the schedule control obtained with the vocal response to that characteristic of the motor responses of other animals. We selected single, multiple, and chain schedules that ordinarily produce disparate response rates at predictable times. In multiple schedules with one component where vocal responding ("Awk") was reinforced with food (fixed-ratio or fixed-interval schedule) and one where the absence of vocal responding was reinforced (differential reinforcement of other behavior), response rates never exceeded 15 responses per minute, but clear schedule differences developed in response rate and pause time. Nonoperant vocal responding was evident when responding endured across 50 extinction sessions at 25% to 40% of the rate during reinforcement. The "enduring extinction responding" was largely deprivation induced, because the operant-level of naive mynahs under food deprivation was comparable in magnitude, but without deprivation the operant level was much lower. Food deprivation can induce vocal responding, but the relatively precise schedule control indicated that operant contingencies predominate when they are introduced.

Gasoline conservation: a procedure for measuring and reducing the driving of college students.

The study sought to motivate college students to reduce the number of miles they drove each day and thus save gasoline. Students in two psychology classes were divided by class into two groups. The experimental group was offered various combinations of prizes such as cash, a tour of a mental-health facility, car servicing, and a university parking sticker for reducing driving. The value of the prize received was scaled in terms of per cent reduction in driving. The contrast group received no inducements. The condition in which the experimental group's mileage reduction was reinforced was counterbalanced by two baseline conditions. Several special recording procedures were used to reduce and detect the possibility of subjects altering their odometers, the source of the driving data. Experimental subjects reduced their average daily mileage by 20% relative to the initial baseline; the contrast group did not change. During the one-month reinforcement condition, the 12 experimental subjects saved some 170 gallons (worth $102) of gasoline.

Producing a change from competition to sharing: effects of large and adjusting response requirements.

Pairs of high-school students matched-to-sample for money. On each trial, the first pair member to complete a fixed ratio of knob-pulling responses could work the matching problem on that trial. Competition occurred when both pair members responded for the problem. Sharing occurred when only one pair member responded on each trial, and the subjects alternated trials. Hence, sharing requires less responding and still allows a moderate number of reinforcers for each subject. Recent research has shown that increasing the response requirement to the point that it may have aversive properties will produce a change from competition to sharing. A related variable is an adjusting schedule that adjusts the subjects' response requirements so that their abilities to take reinforcers are equal. In this way, subjects might learn that competition requires more responding but produces no more reinforcers. However, recent research also suggests that competition decreases over sessions without experimental manipulations. Because of this possibility of a time-related variable, ratio size and an adjusting schedule were studied in a group design. Competition did decrease for all groups over sessions, but the large-ratio groups switched from competition to sharing sooner than the low-ratio groups. The adjusting schedule had a similar but smaller effect.

Manipulation of the mitotic cycle in the treatment of acute myelogenous leukaemia.

A priming dose of cytosine arabinoside (Ara C) was given to 16 children and five adults with acute myelogenous leukaemia (AML) to synchronize leukaemia cells in the DNA synthesis (S) phase of the mitotic cycle. An infusion of this drug, which was continued for 12 h, was started at the time of partial synchronization and was repeated every 6-12 h until the bone marrow was very hypocellular. Complete remission was achieved in 12 of 16 children and in all adults. Two of the four children went into complete remission with the addition of two doses of daunorubicin or adriamycin. These results suggest that partial synchronization of cells in the S phase results in a therapeutic advanatage in the use of Ara C for induction of a remission of AML and that manipulation of the mitotic cycle, as monitored by kinetic studies, may be helpful in planning optimal schedules for drug administration.