Germination of Ascospores of Gibberella zeae after exposure to various levels of relative humidity and temperature.

Fusarium head blight (FHB) is one of the most important cereal diseases in the world and has caused major losses to the grain industry. The principal pathogen causing FHB in North America is Gibberella zeae (anamorph Fusarium graminearum). Information on survival and the conditions under which ascospores remain viable once released from perithecia may assist in refining disease forecasting models. This study measured germination of ascospores after exposure to different temperatures, 15, 20, and 30 degrees C, and levels of relative humidity (RH), 30, 60, and 90% for 4, 24, or 48 h periods. Viability was tested by germination on water agar. Germination rates fell with increasing temperatures at all observation times and at all humidity levels. At 15 and 20 degrees C after 48 h, germination ranged from 74 to 85%, and 52 to 72%, respectively. At 30 degrees C, germination ranged from 36 to 59% after 24 h and from 13 to 47% after 48 h. Germination was highest at 90% RH, except at 30 degrees C after 48 h, and lowest at 60% RH. Successful germination, even under extreme conditions, suggests that ascospores are sufficiently robust to constitute a source of inoculum under most environmental conditions encountered during the growing season.

Effect of Storage on Viability of Fusarium Head Blight-Affected Spring Wheat Seed.

The effects of storage temperature and duration on germination, emergence, and vigor of Fusarium head blight-affected seed were studied in the spring wheat cvs. Glenlea and Roblin. Seed was stored at -10, 2.5, 10, or 20°C. Germination was assessed at cold (5°C) and moderate 20/15°C for 16/8 h daily) temperatures following 0, 8, 16, and 24 weeks of storage. Emergence from a soilless mix was counted 10 days after planting. Vigor was assessed following germination by measuring root and shoot lengths and in emerged plants by determining dry shoot weights. Germination after storage at the three colder temperatures decreased with length of storage, but storage at 20°C did not affect germination. Overall, germination of Fusarium-affected seed at moderate temperatures was significantly lower than for healthy seed. Germination of infected seed at 5°C was better than at moderate temperatures, probably due to lack of fungal activity at low temperatures. Seed treatment with Vitaflo 280 improved germination, but not emergence, of infected seed. However, roots from treated infected seed were shorter than from untreated seed. Emergence of infected seeds was better after storage at 10 and 20°C than at -10 and 2.5°C. Storage temperature did not significantly affect vigor. Dry shoot weight at 14 days was lower after storage at -10 than at 20°C.

Effect of medicating ingredients and other additives on microflora present on swine and chicken feeds from a Manitoba mill.

The occurrence of microfloral components on medicated and non-medicated swine and chicken feed pellets and crumbles, produced in a Manitoba feed mill between June 1991 and October 1992, was determined. Addition of medicates to feeds generally decreased bacterial incidence and increased that of Eurotium spp. fungi. The effect was less pronounced when copper sulphate was added to medicated swine feeds.

Correlation of microcirculation architecture with ultrasound backscatter parameters of uveal melanoma.

Ultrasound tissue characterization parameters of size and acoustic concentration can be used to sub-classify uveal melanoma and estimate the patient's risk of death. Histologically determined microcirculation patterns have also been found to sub-classify uveal melanoma and predict patient's risk of death. This study examines the spatial relationship between tumor features detected by the two techniques. Three dimensional ultrasound images that depict the size and relative concentration of scattering elements in uveal melanoma within a range of approximately 50-120 microns were compared with PAS (without hematoxylin) stained histological sections graded and localized according to tumor microvascular patterns. Both ultrasound parameter imaging and histopathology were accomplished by workers masked to the other procedure. In three of five patients vascular networks were identified histopathologically. The predominant ultrasound feature seen in the regions of the histologically identified networks were clusters of scatterers in the range of approximately 50-80 microns. In the two cases without a network vascular pattern, lower range scatterers dominated the tumor volume. All the cases could be distinguished by the size and distribution of contiguous spatial clusters of acoustic scatterers. Scatterer size features detected in three dimensional ultrasound parameter images can identify tumor regions containing a specific microvascular pattern. Ultrasound tissue characterization features used to sub-classify uveal melanoma may have a biophysical basis related to patterns of tumor microcirculation.

The effect of transducer bandwidth on ultrasonic image characteristics.

PURPOSE: This study was conducted to determine the effect of transducer bandwidth on the characteristics of ophthalmic ultrasound images. METHODS: B-scan images produced using two transducers, one with a narrow bandwidth and the other with a broad bandwidth, both having nominal center frequencies of 10 MHz, were evaluated. Comparative scans were made of a tissue-mimicking phantom, an intraocular tumor, and a vitreous hemorrhage. RESULTS: Results showed that broadband transducers gave improved resolution and finer speckle texture, but had lower sensitivity. Broadband transducers were most suitable for situations in which resolution was more important than sensitivity, such as imaging of tumors. The greater sensitivity of the narrowband probe made it most useful for evaluation of vitreous complications, such as hemorrhage and membranes. CONCLUSION: In addition to transducer frequency, bandwidth should be taken into account when choosing a transducer for a specific ophthalmic imaging application. Both broad- and narrowband transducers have relative advantages in particular applications.

Litigation in residency training programs and suggested due process guidelines for "residents in trouble".

Litigation involving the dismissal of residents has increased in the past decades. A review of relevant court decisions and their implications for residency training programs is provided. To assure due process in such cases and to help programs deal fairly with situations involving problem residents that may never come to frank dismissal, a set of guidelines to assist training programs in dealing ivith residents "in trouble" is presented. The guidelines were developed collaboratively at University of California at Los Angeles (UCLA) and the University of Southern California (USC) and were reviewed and approved by the local hospital, university, and Veterans Affairs counsels to assure compliance with institutional policies and procedures regulating due process for employees and students. The guidelines were also reviewed and approved by an American Association of Directors of Psychiatric Residency Training (AADPRT) task force, but they were never published or widely distributed. Although modifications of these guidelines may be required to meet local educational or institutional variations, or to meet variations in state law or precedent, these suggestions provide a useful template with which to develop adequate and effective due process procedures.

Measurement of ocular tumor volumes from serial, cross-sectional ultrasound scans.

A system has been developed to determine intraocular tumor volume, a characteristic that has been estimated in previous studies from linear dimensions using a variety of models. Volume was determined by tracing tumor boundaries in sequential, parallel ultrasound scans, adding the areas and multiplying by the interslice interval. The in vitro accuracy of the technique was within +/- 2%. The mean difference between volumes determined from replicate in vivo scans of intraocular tumors was 4.3%. Serial scan volumes were, on average, 19% smaller than volumes computed from an ellipsoidal model and 13% smaller than area-rotational volumes. Differences of as much as 50% were observed between serial scan volumes and volumes computed with these models. The results indicate that methods based on either linear measurements or the tumor area in a single cross-section will tend to both systematically overestimate tumor volume and suffer from unpredictable, nonsystematic errors.

Cataract surgery in anticoagulated patients.

A prospective study was performed on 31 patients having planned extracapsular cataract extraction with posterior chamber intraocular lens implantation. The patients were considered to be anticoagulated because of the medications they were taking. The patients were instructed to continue their usual medications throughout the perioperative period including the day of surgery. All patients had routine narcoleptic sedation and retrobulbar anesthesia. The surgical technique was altered to use an inferior corneal traction suture and a single planed clear corneal incision. No intraoperative or postoperative anterior chamber bleeding was seen. The observed complications were increased awareness of corneal sutures, increased endothelial cell loss, delayed visual rehabilitation from with-the-rule astigmatism, and transient corneal edema. All patients achieved 20/40 or better visual acuity without corneal edema by three months post-surgery.

Chloroquine-resistant Plasmodium falciparum malaria at Nchelenge, northeastern Zambia. Follow-up on 515 hospital patients.

From 1986 until 1988 chloroquine sensitivity of Plasmodium falciparum malaria was monitored in 515 hospital patients in Nchelenge district, northeastern Zambia. After treatment with chloroquine 30 mg base/kg, bloodslides were examined on day 2, 4, 6 and 7. The overall resistance rate was 21.4%, of which 29% was R1-, 30% R2-, 18% R3- and 23% R2-3 resistance. Resistance rates were negatively correlated with age and positively with the initial parasitemia. It is suggested that in vivo tests of chloroquine sensitivity also reflect the host's immune status for malaria. In rural areas with chloroquine resistance in vivo testing should be performed on all malaria patients.

A national survey of resident assessment methods.

The authors distributed a questionnaire regarding the assessment of psychiatric residents to 130 directors of residency training programs. Formal examinations were required by 37% of the programs and were being considered by an additional 49%, suggesting that formal examinations may be an integral part of residency training programs within five years. The authors believe that this trend toward utilization of objective measures reflects a growing national concern with accountability in medicine.

Teaching dynamic psychotherapy by observation.

Experience with a seminar demonstrating psychotherapy, interviews with 12 of the treated patients, and a survey of 23 residents have shown the value of this teaching method and its effect on the participants. Generally the patients felt helped and residents were enthusiastic. The teaching format has many valuable features--most important being the inclusion of a faculty-observer.

Some dynamics of male chauvinism.

Male chauvinism was studied in the psychoanalytic therapy of 11 men. It refers to the maintenance of fixed beliefs and attitudes of male superiority, associated with overt or covert depreciation of women. Challenging chauvinist attitudes often results in anxiety or other symptoms. It is frequently not investigated in psychotherapy because it is ego-syntonic, parallels cultural attitudes, and because therapists often share similar bias or neurotic conflict. Chauvinism was found to represent an attempt to ward off anxiety and shame arising from one or more of four prime sources: unresolved infantile strivings and regressive wishes, hostile envy of women, oedipal anxiety, and power and dependency conflicts related to masculine self-esteem. Mothers were more important than fathers in the development of chauvinism, and resolution was sometimes associated with decompensation in wives.