Virtual reconstruction and morphological analysis of the cranium of an ancient Egyptian mummy

A mummy of an Egyptian priestess dating from the 22nd dynasty (c. 770 BC), completely enclosed in an anthropoid (human shaped) coffin, was scanned on a CT scanner. An accurate reconstruction of the cranium was generated from 115 x 2 mm CT images using AVS/Express on a SGI computer. Linear measurements were obtained from six orthogonal cranial views and used in a morphometric analysis software package (CRANID). The analyses carried out were both linear and nearest neighbour discriminant analysis. The results show that there is a 52.9% probability that the mummy is an Egyptian female, with a 24.5% probability that the mummy is an African female. Thus the technique confirms that the coffin contains an Egyptian female, which is consistent with the inscription on the coffin and the shape of the pelvic bones as revealed by plain X-rays. These results show that this technique has potential for analysing forensic cases where the bones are obscured by soft tissue and clothing. This technique may have an application in virtual autopsies.

Mathematical modeling of phosphorus losses from land application of hog and cattle manure

Mathematical models may provide a means to estimate phosphorus (P) losses from land application of manure. Phosphorus losses typically occur during brief episodes of runoff and erosion. Models must be able to simulate P losses during these episodes by representing the basic chemical, physical, and biological processes by which these losses occur. The mathematical model ecosys combines dynamic distributed flow of solutes and nonsolutes through runoff and erosion with convective-dispersive transport of solutes, and both biologically and thermodynamically driven transformations between solutes and nonsolutes. This model was tested against P lost in runoff, erosion, and leachate measured during 90 min of controlled rainfall at 65 mm h(-1) on soils from six sites at which different rates of manure had been applied over the previous 3 to 6 yr. Transport and transformation kinetics in the model enabled it to simulate changes of dissolved inorganic phosphorus (DIP) in runoff from >1.0 to <0.05 mg L(-1) and changes of total phosphorus (TP) in sediment from 15 to 3 mg L(-1) measured during controlled rainfall on soils with diverse P contents. Results from 60-yr model runs using these kinetics with different application rates of cattle manure indicated that (i) a positive interaction exists between annual rainfall and application rate on P losses and (ii) rates greater than 30 Mg ha(-1) yr(-1) would cause TP concentrations in water leaving the site to rise above acceptable limits. The interaction between rainfall and rate suggests that P losses from manure application at any site should be assessed under the upper range of likely rainfall intensities.

Test-retest reliability of cortical evoked potentials using naturally produced speech sounds

OBJECTIVE

To determine if naturally produced speech stimuli evoke distinct neural response patterns that can be reliably recorded in individuals.

DESIGN

Auditory cortical evoked potentials were obtained from seven normal-hearing young adults in response to four naturally produced speech tokens (/bi/, /pi/, /[U0283]i/, and /si/). Stimuli were tokens from the standardized UCLA version of the Nonsense Syllable Test (NST) ( Dubno & Schaefer, 1992). Using a repeated measures design, subjects were tested and then retested within an 8-day period.

RESULTS

Auditory cortical evoked potentials elicited by naturally produced speech sounds were reliably recorded in individuals. Also, naturally produced speech tokens, representing different acoustic cues, evoked distinct neural response patterns.

CONCLUSIONS

1) Cortical evoked potentials elicited by naturally produced speech sounds can be reliably recorded in individuals. 2) Naturally produced speech tokens, representing different acoustic cues, evoke distinct neural response patterns. 3) Given the reliability of the response, this work has potential application to the study of neural processing of speech in individuals with communication disorders as well as changes over time after various types of auditory rehabilitation.

When immigrants are not migrants: counting arrivals of the foreign born using the U.S. census

"This paper compares characteristics of recent immigrant arrivals in the United States using two measures from the decennial U.S. census: the came-to-stay question and the migration question.... Among recent arrivals, defined as those who reported they came to stay in the quinquennium preceding the census, a large number were resident in the United States five years before the census date. Furthermore, the proportion of recent arrivals present in the United States five years before the census increased between 1975-1980 and 1985-1990.... Generally, in both the 1975-1980 and 1985-1990 cohorts, those resident in the United States five years before the census have significantly less schooling and lower incomes than those who were abroad."

Esthetic considerations in removable prosthodontics

Patients requiring extensive replacement of teeth with removable prostheses are indeed esthetic orphans in many contemporary dental practices. Although the advent of successful osseointegration has dramatically reduced the need for removable prostheses, there are still many patients who for health, anatomic, psychological, or financial reasons are not candidates for implants. These patients deserve the same level of esthetic restorative dentistry as those who are restored with fixed prostheses. Clearly, the restorative dentist has the greatest flexibility from an esthetic standpoint with complete dentures. Soft and hard tissues can be replaced with contemporary characterized denture-base materials, and a truly infinite variety of tooth forms, shades, and arrangements can be used to meet the expectations of the most demanding patient. For partially edentulous patients, the major problem is designing a removable partial denture that avoids the unsightly display associated with conventional clasp assemblies. There are strategies available to accomplish this effectively while establishing an environment for optimal periodontal health, and to minimize destructive stresses on the abutment teeth.

CLINICAL SIGNIFICANCE

This article discusses the procedures essential for providing an upscale, quality esthetic service with removable prostheses. Effective strategies to eliminate unsightly clasp assemblies with removable partial dentures are described.

Perceptual "vowel spaces" of cochlear implant users: implications for the study of auditory adaptation to spectral shift

Cochlear implant (CI) users differ in their ability to perceive and recognize speech sounds. Two possible reasons for such individual differences may lie in their ability to discriminate formant frequencies or to adapt to the spectrally shifted information presented by cochlear implants, a basalward shift related to the implant's depth of insertion in the cochlea. In the present study, we examined these two alternatives using a method-of-adjustment (MOA) procedure with 330 synthetic vowel stimuli varying in F1 and F2 that were arranged in a two-dimensional grid. Subjects were asked to label the synthetic stimuli that matched ten monophthongal vowels in visually presented words. Subjects then provided goodness ratings for the stimuli they had chosen. The subjects' responses to all ten vowels were used to construct individual perceptual "vowel spaces." If CI users fail to adapt completely to the basalward spectral shift, then the formant frequencies of their vowel categories should be shifted lower in both F1 and F2. However, with one exception, no systematic shifts were observed in the vowel spaces of CI users. Instead, the vowel spaces differed from one another in the relative size of their vowel categories. The results suggest that differences in formant frequency discrimination may account for the individual differences in vowel perception observed in cochlear implant users.

Conjoint recognition and phantom recollection

A new methodology for measuring illusory conscious experience of the "presentation" of unstudied material (phantom recollection) is evaluated that extracts measurements directly from recognition responses, rather than indirectly from introspective reports. Application of this methodology in the Deese-Roediger-McDermott (DRM) paradigm (Experiments 1 and 2) and in a more conventional paradigm (Experiment 3) showed that 2 processes (phantom recollection and familiarity) contribute to false recognition of semantically related distractors. Phantom recollection was the larger contributor to false recognition of critical distractors in the DRM paradigm, but surprisingly, it was also the larger contributor to false recognition of other types of distractors. Variability in false recognition was tied to variability in phantom recollection. Experimental control of phantom recollection was achieved with manipulations that were motivated by fuzzy-trace theory's hypothesis that the phenomenon is gist-based.

Conjoint recognition and phantom recollection

A new methodology for measuring illusory conscious experience of the "presentation" of unstudied material (phantom recollection) is evaluated that extracts measurements directly from recognition responses, rather than indirectly from introspective reports. Application of this methodology in the Deese-Roediger-McDermott (DRM) paradigm (Experiments 1 and 2) and in a more conventional paradigm (Experiment 3) showed that 2 processes (phantom recollection and familiarity) contribute to false recognition of semantically related distractors. Phantom recollection was the larger contributor to false recognition of critical distractors in the DRM paradigm, but surprisingly, it was also the larger contributor to false recognition of other types of distractors. Variability in false recognition was tied to variability in phantom recollection. Experimental control of phantom recollection was achieved with manipulations that were motivated by fuzzy-trace theory's hypothesis that the phenomenon is gist-based.

[Sickness, Healing, and Health Services: social representations, practices, and demands among the Baníwa]

The research for this paper was conducted in São Gabriel da Cachoeira, in the northwestern Amazon, with the Baníwa indigenous people, in partnership with indigenous organizations, seeking to understand the relations among the group's cosmology, their system of representations of sickness and healing practices, and their transformation through inter-ethnic contact. The recording of myths showed the origin of the diseases and demonstrated the existence of several traditional categories of sickness, guiding traditional healing practices and the incorporation of biomedical knowledge. The Baníwa's cosmology operates like a reception system for biomedical information, which the people grasp according to the logic of mythical thought. Similar cognitive strategies are used to generate the demands that indigenous leaders submit to the Health Councils and Health Services.

Transmission electron microscopy of yeast

The challenges of sample preparation can limit a researcher's selection of transmission electron microcopy (TEM) for analysis of yeast. However, with the exception of thin sectioning, preparation of well-fixed and infiltrated samples of yeast cells is achievable by any reasonably equipped laboratory. This review presents a general overview of TEM sample preparation methods and detailed protocols for chemical fixation of yeast for ultrastructural analysis and immunolabeling. For ultrastructural analysis, the most commonly used chemical fixation involves treatment with glutaraldehyde followed by either potassium permanganate or osmium. Prior to osmium postfixation, the cell wall must be enzymatically digested to allow optimal fixation and embedding. Freeze substitution methods continue to provide the highest quality of fixation, but equipment needed for these protocols is not generally available to many labs. The low viscosity of Spurr's resin makes it the resin of choice for ultrastructure studies. Immunoelectron microscopy has enjoyed great success in analysis of yeast molecular organization. For immunoelectron microscopy, glutaraldehyde/formaldehyde-fixed cells are embedded in LR White resin. The thin sections are then treated in much the same way as an immunoblot: following blocking, they are incubated in primary antiserum, washed, and then incubated in gold-labeled secondary antiserum.

Needs and opportunities for improving the health, safety, and productivity of medical research facilities

Medical research facilities, indeed all the nation's constructed facilities, must be designed, operated, and maintained in a manner that supports the health, safety, and productivity of the occupants. The National Construction Goals, established by the National Science and Technology Council, envision substantial improvements in occupant health and worker productivity. The existing research and best practices case studies support this conclusion, but too frequently building industry professionals lack the knowledge to design, construct, operate, and maintain facilities at these optimum levels. There is a need for more research and more collaborative efforts between medical and facilities engineering researchers and practitioners in order to attain the National Construction Goals. Such collaborative efforts will simultaneously support attainment of the National Health Goals. This article is the summary report of the Healthy Buildings Committee for the Leadership Conference: Biomedical Facilities and the Environment sponsored by the National Institutes of Health, the National Association of Physicians for the Environment, and the Association of Higher Education Facilities Officers on 1--2 November 1999 in Bethesda, Maryland, USA.

Comparison of three a priori methods and one empirical method in predicting lithium dosage requirements

The precision and bias of three a priori methods and an empirical method for predicting lithium dosage requirements were studied. Data on serum lithium concentrations were collected from inpatient medical records at a state psychiatric hospital. Predicted daily lithium doses were calculated by using a priori methods proposed by Zetin et al., Jermain et al. and Pepin et al., and an empirical method and compared with the patients' actual dosages. Similar comparisons were made with respect to serum lithium concentrations at steady state. Absolute mean error and mean error were calculated to assess the precision and bias of each a priori method. The records of 47 patients were used in the study. Average mean error for dosage predictions was -130.41, -187.69, 170.80, and -357.23 mg/day for the Jermain, Pepin, Zetin, and empirical methods, respectively. Average mean error for serum lithium concentration predictions was 0.11, -0.09, and 0.37 meq/L for the Jermain, Pepin, and empirical methods, respectively. The Jermain and empirical methods significantly overpredicted concentration and underpredicted dosage. The Zetin method overpredicted dosage. The Pepin method underpredicted dosage but not concentration. The average difference in dosage error among the methods was only 73.3 mg/day. Three a priori dosing methods were similar to an empirical method in their ability to predict lithium dosages. All methods were biased. Although all a priori methods were more precise than the empirical method, the clinical significance is unclear.

The Brucella abortus CcrM DNA methyltransferase is essential for viability, and its overexpression attenuates intracellular replication in murine macrophages

The CcrM DNA methyltransferase of the alpha-proteobacteria catalyzes the methylation of the adenine in the sequence GAnTC. Like Dam in the enterobacteria, CcrM plays a regulatory role in Caulobacter crescentus and Rhizobium meliloti. CcrM is essential for viability in both of these organisms, and we show here that it is also essential in Brucella abortus. Further, increased copy number of the ccrM gene results in striking changes in B. abortus morphology, DNA replication, and growth in murine macrophages. We generated strains that carry ccrM either on a low-copy-number plasmid (strain GR131) or on a moderate-copy-number plasmid (strain GR132). Strain GR131 has wild-type morphology and chromosome number, as assessed by flow cytometry. In contrast, strain GR132 has abnormal branched morphology, suggesting aberrant cell division, and increased chromosome number. Although these strains exhibit different morphologies and DNA content, the replication of both strains in macrophages is attenuated. These data imply that the reduction in survival in host cells is not due solely to a cell division defect but is due to additional functions of CcrM. Because CcrM is essential in B. abortus and increased ccrM copy number attenuates survival in host cells, we propose that CcrM is an appropriate target for new antibiotics.

Race, region and the territorial politics of immigration in the US

Zelinsky and Lee recently unveiled a model of the sociospatial process of immigrant settlement designed to augment and possibly supplant the well-known theories of assimilation and pluralism. Although in some ways new, their work continues a tradition in social science that treats the settlement geography of immigrants as a measure of their more general fit into American society. The authors question the prevailing assumption that immigrant settlement patterns represent a barometer of their adaptation, or lack thereof, to a host society. This critique of the concepts of assimilation, pluralism and Zelinsky and Lee's alternative "heterolocal" model of immigrant settlement pivots around the issues of spatial scale and race. The authors argue that the contestations over immigration and how well immigrants fit into society are increasingly constructed at the regional scale. The authors also assert that questions race infuse almost all aspects of these debates. The transformation of America's largest city-regions into places of non-White immigrants, and the shifting political balance of power to states like California through immigration-driven reapportionment, are touchstones for anti-immigration initiatives and associated local and national debate. Fear of racial regional changes underpins an increasingly powerful response to immigration. The reactions elicited by these settlement geographies fall under the heading the authors call the "territorial politics of immigration".