Calculation of dose coefficients for radionuclides produced in a spallation neutron source utilizing NUBASE and the evaluated nuclear structure data file databases

Based on a mercury spallation neutron source target, the UNLV Transmutation Research Program has identified 72 radionuclides with a half-life greater than or equal to a minute as lacking an appropriate reference for a published dose coefficient according to existing radiation safety dose coefficient databases. A method was developed to compare the nuclear data presented in the ENSDF and NUBASE databases for these 72 radionuclides. Due to conflicting or lacking nuclear data in one or more of the databases, internal and external dose coefficient values have been calculated for only 14 radionuclides, which are not currently presented in Federal Guidance Reports Nos. 11, 12, and 13 or Publications 68 and 72 of the International Commission on Radiological Protection. Internal dose coefficient values are reported for inhalation and ingestion of 1 microm and 5 microm AMAD particulates along with the f1 values and absorption types for the adult worker. Internal dose coefficient values are also reported for inhalation and ingestion of 1 microm AMAD particulates as well as the f1 values and absorption types for members of the public. Additionally, external dose coefficient values for air submersion, exposure to contaminated ground surface, and exposure to soil contaminated to an infinite depth are also presented.

Quality assurance methods and procedures used to verify consistency in calculating dose coefficients

The development of a spallation neutron source with a mercury target will lead to the production of rare radionuclides. The dose coefficients for many of these radionuclides have not yet been published. A collaboration of universities and national labs has taken on the task of calculating dose coefficients for the rare radionuclides using the software package DCAL. The working group developed a procedure for calculating dose coefficients and a quality assurance (QA) program to verify the calculations completed. The first portion of this QA program was to verify that each participating group could independently reproduce the dose coefficients for a known set of radionuclides. The second effort was to divide the group of rare radionuclides among the independent participants in a manner that assured that each radionuclide would be redundantly and independently calculated, and the results subsequently be submitted for publication in a separate manuscript. The final aspect of this program was to resolve any discrepancies arising among the participants as a group. The output of the various software programs for six QA radionuclides, 144Nd, 201Au, 50V, 61Co, 41Ar, and 38S were compared among all members of the working group. Initially, a few differences in outputs were identified. This exercise identified weaknesses in the procedure, which has since been revised. After the revisions, dose coefficients were calculated and compared to published dose coefficients with good agreement. The present efforts involve generating dose coefficients for the rare radionuclides anticipated to be produced from the spallation neutron source should a mercury target be employed.

Preimplantation genetic diagnosis

Preimplantation genetic diagnosis (PGD) has now been used in human fertility centers for a decade. To this end, diagnostic analysis is conducted on polar bodies or single blastomeres from biopsied embryos before the embryos are transferred, allowing the selection of normal embryos before a pregnancy has been established. Advances in technology available for PGD are described, including fluorescent in situ hybridization (FISH), interphase chromosome conversion, comparative genomic hybridization (CGH), fluorescent polymerase chain reaction (PCR), multiplex PCR, and whole genome amplification. These techniques support the diagnosis of a number of diseases at the single-cell level.

The effects of telencephalic lesions on visually mediated prey orienting behavior in the leopard frog (Rana pipiens). I. The effects of complete removal of one telencephalic lobe, with a comparison to the effects of unilateral tectal lobe lesions

In this paper, we report studies aimed at characterizing the relationship between forebrain and midbrain systems involved in the control of prey orienting behavior in the leopard frog. In frogs, unilateral forebrain lesions, like unilateral tectal lobe lesions, have their most prominent effects in the contralateral monocular visual field. Such lesions produce partial reductions in response frequency in the binocular visual field as well. Similar sequelae follow unilateral tectal lobe removal. These findings suggest that the effects of unilateral forebrain removal can be largely attributed to removal of a facilitating influence on the tectal lobe on the same side of the brain. In the case of both forebrain and midbrain lesions, behavior was assayed not only in terms of the frequency with which animals responded to stimuli at various locations in the visual field (as is usually done) but also in terms of the latency of whatever responses were observed. A striking inverse relationship between response frequency and response latency was found, both in lesioned and in normal frogs. This relationship has not previously been noticed, doesn't appear to be an obvious consequence of any existing models of the neuronal circuitry underlying anuran orienting behavior, and is difficult to account for in terms of the time scales associated with axonal conduction times and synaptic delays. It may be easier to account for in terms of the responses to perturbation of large interacting systems of neurons, and this possibility seems worthy of further exploration.

The effects of telencephalic lesions on visually mediated prey orienting behavior in the leopard frog (Rana pipiens). II. The effects of limited lesions to the telencephalon

Unilateral removal of the telencephalon in the leopard frog, Rana pipiens, produces a contralateral deficit in visual prey orienting behavior [Patton and Grobstein, 1997]. In mammals, such deficits are most commonly associated with damage to the isocortex, a pallial derived structure. In contrast, we here report that in leopard frogs, lesions that remove substantial areas of one telencephalic lobe, including virtually the entire pallium, have no discernible effect on visual orienting behavior. Restricted lesions to the ventrocaudal telencephalon, however, produce an effect that closely resembles that produced by the complete removal of one telencephalic lobe. The 'critical area' that is both included in all lesions that are effective in producing a severe deficit and excluded from all ineffective lesions includes a portion of the caudal striatum. The striatum is known to play a significant role in anuran vision. It thus seems likely that the deficit produced by unilateral removal of the telencephalon in the leopard frog is due specifically to the removal of the caudal striatum. Unilateral lesions to the striatum have previously been shown to produce a contralateral deficit in visual orienting behavior in cats, and a role for the striatonigral pathway in the production of the visual orienting deficit that follows visual cortex lesions has been proposed. The current findings call attention to the possible general importance of the striatum in the control of vertebrate visual orienting behaviors.

Literacy and self-reported educational levels in relation to Mini-mental State Examination scores

BACKGROUND AND OBJECTIVES

Because of its brevity and ease of use, the Mini-mental State Examination (MMSE) is commonly used to screen and follow patients with cognitive impairment. This pilot study attempted to determine the relationships between literacy, age, and self-reported educational level and the total MMSE score.

METHODS

Cross-sectional analysis of all patients was followed by a family practice group at five local nursing homes. The associations between the patients' MMSE scores; literacy, as measured by the Rapid Estimate of Adult Literacy in Medicine (REALM); self-reported educational level; and age were determined using Pearson's correlation coefficient and stepwise multivariate linear regression.

RESULTS

A total of 105 patients completed the study. Linear regression analysis showed that MMSE scores were significantly predicted by REALM score (P < .001) and the patient's age (P < .02). However, after accounting for REALM score and age, the self-reported educational level was not related to the MMSE score (P < .8). A significant relationship was seen between the REALM score and the subjects' self-reported educational levels (r = .44, P < .001) but not the subjects' ages (r = -.17, P < 0.09). A significant linear correlation was found between the MMSE and REALM scores (r = .71, P < .0001) and a significant inverse correlation was seen between MMSE scores and the patients' ages (r = -.28, P < .004). The correlation coefficient between the patients' MMSE scores and the self-reported educational levels was .33 (P < .0007).

CONCLUSIONS

Practitioners who rely on the MMSE should be aware that patients may score in the demented range because they cannot read well enough to accurately complete the test. Literacy testing with REALM or other instruments may help identify such patients.

Diagnosis of cornual obstruction by transcervical fallopian tube cannulation

Interstitial fallopian tube obstruction (IFTO) occurs in 15% of hysterosalpingograms (HSG) performed for infertility. Conventional HSG or laparoscopy may not differentiate cornual spasm or other temporary cause from true obstruction. We used transcervical cannulation of the proximal oviduct with a 3-F Teflon catheter and flexible guidewire 0.018 inch (0.043 cm) in diameter under hysteroscopic or fluoroscopic guidance to evaluate IFTO in 28 patients. Fluoroscopic catheterization techniques with selective salpingography demonstrated patency in 84% of obstructed tubes. Hysteroscopic cannulation with direct visualization by laparoscopy or laparotomy was successful in 92%. In one patient, perforation of the isthmus occurred without sequelae. Transcervical coaxial cannulation of the proximal oviduct is an effective method for evaluating cornual obstruction.