Showing papers by "University of Massachusetts Boston published in 1998"

Genetic Inhibition by Double-Stranded RNA

Abstract: A process is provided of introducing an RNA into a living cell to inhibit gene expression of a target gene in that cell. The process may be practiced ex vivo or in vivo. The RNA has a region with double-stranded structure. Inhibition is sequence-specific in that the nucleotide sequences of the duplex region of the RNA and of a portion of the target gene are identical. The present invention is distinguished from prior art interference in gene expression by antisense or triple-strand methods.

Natural Forest Management and Conservation of Biodiversity in Tropical Forests

Abstract: As a reaction to the continued dwindling of tropical forest resources, many research and develop- ment organizations have turned to the idea of natural forest management in the hope of making tropical for- est lands more profitable while maintaining biodiversity. Assertions of sustainability in logging practices have been inadequately supported, however. We begin with a review of the present knowledge of the effects of logging operations on various organisms. Post-harvest surveys of a spectrum of tropical forests indicate a range of logging effects from local extirpation to substantial increases in local densities of some species. The state of our knowledge does not permit quantitative predictions, but logging at any level appears to have sim- plifying and homogenizing effects on tropical forest diversity when examined at community or regional scales. Furthermore, the social and economic problems presented by natural forest management systems have not yet been adequately addressed. We present alternatives to the strong emphasis on "sustainable natural forest management" as a means of retaining the diversity of tropical forest communities. These alternatives include increased support for management of secondary forests, restoration of degraded lands, plantation forestry, nontimber uses for some forests, changes in accounting procedures to reflect the true value of natu- ral forests, and support for forestry agencies charged with protecting forest reserves. Manejo de Bosques Naturales y Conservacion de la Biodiversidad en Bosques Tropicales Resumen: Como una reaccion a la constante reduccion de los recursos en bosques tropicales, muchos inves- tigadores y organizaciones de desarrolo se han enfocado en la idea del manejo de bosques naturales, con la esperanza de que las tierras con bosques tropicales sean mas rentables, al mismo tiempo que se pretende mantener la biodiversidad. Sin embargo, algunas aseveraciones de sustentabilidad en practicas de tala han sido inadecuadamente soportadas. Iniciamos con una revision del conocimiento actual de los efectos de opera- ciones de tala en varios organismos. Estudios posteriores a las cosechas en un espectro de bosques tropicales indican que el rango de efectos de la tal varian desde la extriparcion local hasta el incremento sustancial en la densidad local de algunas especies. El estado actual de nuestro conocimiento no nos pemite realizar predic- ciones cuantitativas, pero la tala a cualquier nivel aparenta tener efectos de simplificacion y homogeneiza- cion en la diversidad de los bosques tropicales cuando se examina a nivel de escala regional. Mas aun, los problemas sociales y economicos en sistemas de manejo de bosques naturales no han sido abordados adecua- damente. Presentamos alternativas para el enfatizado "manejo sustentable de bosques naturales" como una medida para retener la diversidad de las comunidades de bosques tropicales. Estas alternativas incluyen un soporte mayor en el manejo de bosques secundarios, la restauracion de tierras degradadas, plantaciones forestales, usos diferentes a la tala en algunos bosques, cambios en los procediminetos de contabilidad para reflejar el valor verdadero de los bosques naturales y soporte en las agencias forestales encargadas de la pro- teccion de las reservas forestales.

Three-dimensional object recognition is viewpoint dependent

Abstract: The human visual system is faced with the computationally difficult problem of achieving object constancy: identifying three-dimensional (3D) objects via two-dimensional (2D) retinal images that may be altered when the same object is seen from different viewpoints1 A widely accepted class of theories holds that we first reconstruct a description of the object's 3D structure from the retinal image, then match this representation to a remembered structural description If the same structural description is reconstructed from every possible view of an object, object constancy will be obtained For example, in Biederman's2 oft-cited recognition-by-components (RBC) theory, structural descriptions are composed of sets of simple 3D volumes called geons (Fig 1), along with the spatial relations in which the geons are placed Thus a mug is represented in RBC as a noodle attached to the side of a cylinder, and a suitcase as a noodle attached to the top of a brick The attraction of geons is that, unlike more complex objects, they possess a small set of defining properties that appear in their 2D projections when viewed from almost any position (eg, all three views of the brick in Fig 1 include a straight main axis, parallel edges, and a straight cross section) According to the RBC theory, a complex object can therefore be recognized from its constituent geons, which can themselves be recognized from any viewpoint

Does Human Facial Attractiveness Honestly Advertise Health? Longitudinal Data on an Evolutionary Question

Abstract: Inspired by the evolutionary conjecture that sexually selected traits function as indicators of pathogen resistance in animals and humans, we examined the notion that human facial attractiveness provides evidence of health. Using photos of 164 males and 169 females in late adolescence and health data on these individuals in adolescence, middle adulthood, and later adulthood, we found that adolescent facial attractiveness was unrelated to adolescent health for either males or females, and was not predictive of health at the later times. We also asked raters to guess the health of each stimulus person from his or her photo. Relatively attractive stimulus persons were mistakenly rated as healthier than their peers. The correlation between perceived health and medically assessed health increased when attractiveness was statistically controlled, which implies that attractiveness suppressed the accurate recognition of health. These findings may have important implications for evolutionary models.

The Cultural Production of the Educated Person: Critical Ethnographies of Schooling and Local Practice

Abstract: The Cultural Production of the Educated Person: Critical Ethnographies of Schooling and Local Practice. Bradley Levinson. Douglas Foley, and Dorothy Holland, eds. Albany: State University of New York Press, 1996. 299 pp.

Closing the Gate: Race, Politics, and the Chinese Exclusion Act

Abstract: The Chinese Exclusion Act of 1882, which barred practically all Chinese from American shores for ten years, was the first federal law that banned a group of immigrants solely on the basis of race or nationality. By changing America's traditional policy of open immigration, this landmark legislation set a precedent for future restrictions against Asian immigrants in the early 1900s and against Europeans in the 1920s. Tracing the origins of the Chinese Exclusion Act, Andrew Gyory presents a bold new interpretation of American politics during Reconstruction and the Gilded Age. Rather than directly confront such divisive problems as class conflict, economic depression, and rising unemployment, he contends, politicians sought a safe, nonideological solution to the nation's industrial crisis--and latched onto Chinese exclusion. Ignoring workers' demands for an end simply to imported contract labor, they claimed instead that working people would be better off if there were no Chinese immigrants. By playing the race card, Gyory argues, national politicians--not California, not organized labor, and not a general racist atmosphere--provided the motive force behind the era's most racist legislation. |Analyzes the Chinese Exclusion Act of 1882 from a national perspective. By playing the race card, national politicians--not California, not organized labor, and not a general racist atmosphere--were responsible for this law.

Multicast with proactive forward error correction

Abstract: Apparatus and methods for multicasting blocks of data to a plurality of receivers, the blocks including a first block and a second block, the first block comprising k1≧1 data packets, the transmission of the first block comprising an initial transmission of the k1 data packets and h1≧repair packets and one or more subsequent transmissions of additional repair packets in response to repair requests, wherein any k1 of the data packets and repair packets provide sufficient information to recover the k1 data packets; and multicasting a second block comprising k2≧1 data packets, the transmission of the second block comprising an initial transmission of the k2 data packets and h2≧repair packets, wherein any k2 of the data packets and the repair packets of the second block provide sufficient information to recover the k2 data packets of the second block and either or both k2 and h2 differ from k1 and h1, respectively. The invention provides multicast data transmission with adaptive proactive forward error correction (FEC) in combination with automatic repair requesting (ARQ), and reduces response feedback implosion in multicast over digital packet networks.

Adaptive media control

Abstract: A media control approach that supports transmission of data streams with QoS requirements, such as minimum throughput or maximum delay, while adapting to the changing characteristics of the transmission medium. The media control approach includes use of a polling manager (324) and a resource manager (322). The resource manager (322) provides an admission control procedure that prevents admission of sessions that cannot be supported by the system and allocates network resources needed to support admitted sessions. The polling manager (324) uses an efficient 'just in time' polling of stations based on their allocated bandwidth or communication rates. Stations that do not use their allocated rates are polled less often than those which use their allocation, thereby increasing the total throughput of the system and providing proper quality of service support for real-time application.

Reading the Windows to the Soul: Evidence of Domain-Specific Sparing in Williams Syndrome

Abstract: This study tested the hypothesis that Williams syndrome, a rare genetic neurodevelopmental disorder with an unusual cognitive phenotype, involves spared abilities in the domain of understanding other minds. A group of retarded adults with Williams syndrome was compared to an age-,IQ-,and languagematched group of adults with Prader-Willi syndrome, another genetic disorder without the cognitive characteristics of Williams syndrome, and a group of age-matched normal adults, on a task that taps mentalizing ability. The task involved selecting the correct labels to match photographs of complex mental state expressions in the eye region of the face. The adults with Williams syndrome performed significantly better than the adults with Prader-Willi on this task, and about half the group performed in the same range as the normal adults. These findings are consistent with anecdotal evidence about Williams syndrome and provide evidence that mentalizing is a distinct cognitive domain.This spared cognitive capacity may be linked to the relative sparing of limbic-cerebellar neural substrate in Williams syndrome, which is also connected to cortico-frontal regions that are known to be involved in understanding complex mental states.

The Crisis of Minorities in Ethnic States: The Case of Palestinian Citizens in Israel

Abstract: The vast majority of states in the international system, democratic and non-democratic, are multi-ethnic (Gurr 1993). A liberal-democratic multi-ethnic state serves the collective needs of all its citizens regardless of their ethnic affiliation, and citizenship—legally recognized membership in the political structure called a state—is the single criterion for belonging to the state and for granting equal opportunity to all members of the system. Whether a multi-ethnic democratic state should provide group rights above and beyond individual legal equality is an ongoing debate (Gurr & Harff 1994).

Anabolic Steroid Use by Male and Female Middle School Students

Abstract: Background . The prevalence of anabolic steroid use by high school and college students has been reported in the literature. However, rumors persist regarding the use of steroids by younger populations. Objective . To assess the extent of steroid use by male and female middle school students and to explore their attitudes and perceptions about these drugs. Methods . A confidential self-report questionnaire was administered to 466 male and 499 female students between 9 and 13 years of age (mean ± SD, 11.4 ± 0.9 years) in 5th, 6th, and 7th grades from four public middle schools in Massachusetts. The number of students reporting steroid use and differences between users9 and nonusers9 underlying attitudes and perceptions about these drugs were evaluated. Results . The response rate was 82% (965/1175 eligible). Results indicated that 2.7% of all middle school students reported using steroids; 2.6% were males and 2.8% were females. When steroid users were compared with nonusers, 47% versus 43% thought that steroids make muscles bigger; 58% versus 31% thought that steroids make muscles stronger; 31% versus 11% thought that steroids improve athletic performance; 23% versus 13% thought that steroids make one look better; 23% versus 9% knew someone their own age who currently took steroids; 38% versus 4% were asked by someone to take steroids; 54% versus 91% thought that steroids were bad for them; and 35% versus 2% indicated that they would take steroids in the future. Additional analyses determined steroid user involvement in sports and activities. Conclusion . The results of this study suggest that the problem of illicit steroid use extends to children and young adolescents and that a segment of this population is mindful of the potential physiologic effects of steroids. This information will be useful to pediatricians, sport authorities, and school teachers whose guidance will become increasingly more important as steroid educational interventions for male and female middle school students are developed.

Why are sicker patients less satisfied with their medical care ? tests of two explanatory models

Abstract: Two explanations were tested for why patients who are less healthy tend to be less satisfied with their medical care than healthier patients. The explanations were (a) that poor health produces dissatisfaction directly and (b) that poor health produces dissatisfaction through the mediating effect of physicians' behavior. Two studies are presented that measured patients' health status, patients' satisfaction with care, and their physicians' communication as recorded on audiotape. In Study 1, 114 patients had first visits with rheumatologists; in Study 2, 649 patients had continuing-care visits with physicians in internal and family medicine. Causal modeling revealed that the first study supported the direct explanation. The second study also supported the direct explanation, as well as the mediation explanation with respect to the physician's use of social conversation.

The Cultural Production of the Educated Person: Critical Ethnographies of Schooling and Local Practice

Abstract: The Cultural Production of the Educated Person: Critical Ethnographies of Schooling and Local Practice. Bradley A. Levinson, Douglas E. Foley, and Dorothy C. Holland, eds. Albany: State University of New York Press, 1996. 338 pp.

High efficiency alkaline protein extraction

Abstract: A process for isolating edible protein from animal muscle by solubilizing the protein in an alkaline aqueous solution is disclosed.

Social Value Orientations and Decisions to Take Proenvironmental Action1

Abstract: This study assessed whether social value orientations influence decisions to actively support a proposal for a transportation pollution reduction program. Participants with prosocial or proself orientations were given the opportunity to send letters of support or opposition to the program director. Proself participants were more likely to send letters opposing the program, whereas prosocial participants were more likely to send letters of support. Although proself and prosocial participants reported equivalent support for the program and equivalent perceptions of the program's environmental benefits, proself participants reported higher perceptions of personal costs associated with the program. Social value orientations may lead to differences in environmental behaviors, primarily because of differences in perceptions of the personal costs incurred from engaging in these behaviors.

Bathymetric patterns of body size: implications for deep-sea biodiversity

Abstract: The evolution of body size is a problem of fundamental interest, and one that has an important bearing on community structure and conservation of biodiversity. The most obvious and pervasive characteristic of the deep-sea benthos is the small size of most species. The numerous attempts to document and explain geographic patterns of body size in the deep-sea benthos have focused on variation among species or whole faunal components, and have led to conflicting and contradictory results. It is important to recognize that studying size as an adaptation to the deep-sea environment should include analyses within species using measures of size that are standardized to common growth stages. An analysis within eight species of deep-sea benthic gastropods presented here reveals a clear trend for size to increase with depth in both larval and adult shells. An ANCOVA with multiple comparison tests showed that, in general, size–depth relationships for both adult and larval shells are more pronounced in the bathyal region than in the abyss. This result reinforces the notion that steepness of the bathymetric selective gradient decreases with depth, and that the bathyal region is an evolutionary hotspot that promotes diversification. Bathymetric size clines in gastropods support neither the predictions of optimality models nor earlier arguments based on tradeoffs among scaling factors. As in other environments, body size is inversely related to both abundance and species density. We suggest that the decrease in nutrient input with depth may select for larger size because of its metabolic or competitive advantages, and that larger size plays a role in limiting diversity. Adaptation is an important evolutionary driving force of biological diversity, and geographic patterns of body size could help unify ecological and historical theories of deep-sea biodiversity.

Reactions of adult and teenaged smokers to the Massachusetts tobacco tax.

Abstract: OBJECTIVES: This study assessed smokers' reactions to a 25 cents cigarette tax imposed in Massachusetts. METHODS: A statewide telephone survey of 1783 adult smokers and 216 teenaged smokers was conducted. RESULTS: Among adult smokers, 3.5% reported that they had stopped smoking, owing in part to the price increase; 35% had considered quitting and 19% had attempted to cut the cost of smoking by switching to cheaper brands or cutting down. Among teenagers, 21% had considered quitting and 26% had cut costs. Low-income smokers were more responsive to the price increase than more affluent smokers. CONCLUSIONS: A modest and temporary price increase promoted quitting among adult smokers and reduced cigarette consumption among low-income teenagers.

The mouse gene encoding the testis-specific isoform of Poly(A) binding protein (Pabp2) is an expressed retroposon: intimations that gene expression in spermatogenic cells facilitates the creation of new genes.

Abstract: The gene encoding the testis-specific isoform of mouse poly(A) binding protein (Pabp2) has been isolated and sequenced. Unexpectedly, comparison of the sequence of genomic and cDNAs demonstrated that the Pabp2 gene lacks introns, whereas all other functional Pabp genes in plants, amphibians, and mammals contain introns. Thus, the mouse Pabp2 gene is a retroposon, created by synthesizing a reverse transcriptase copy of a processed mRNA and inserting the copy into the genome. The Pabp2 retroposon is unusual because it is functional: previous work demonstrates that its promoter drives the accumulation of Pabp2 mRNA in meiotic and early haploid spermatogenic cells, and the Pabp2 mRNA encodes a protein whose size and RNA-binding specificities are characteristic of PABP in plants, yeast, and mammals (Kleene et al. 1994). Two novel factors can be implicated in the retention of function of the Pabp2 retroposon. First, the promoter of the Pabp2 gene is not derived from its intron-containing progenitor, Pabp1. Second, mRNAs encoding somatic PABP isoform, PABP1, are present at high levels in meiotic and haploid spermatogenic cells. Both features contrast with the phosphoglycerate kinase 2 retroposon, which is believed to compensate for the depletion of the somatic isoform due to X-chromosome inactivation in meiotic spermatogenic cells. We also document that more functional retroposons are expressed in meiotic and haploid spermatogenic cells than in any other tissue and speculate that transcriptional derepression in spermatogenic cells favors the creation of expressed retroposons.

A longitudinal analysis of nursing home outcomes.

Abstract: OBJECTIVE: To investigate resident and facility attributes associated with long-term care health outcomes in nursing homes. DATA SOURCES: Quarterly Management Minutes Questionnaire (MMQ) survey data for Medicaid case-mix reimbursement of nursing homes in Massachusetts from 1991 to 1994, for specification of outcomes and resident attributes. Facility attributes are specified from cost report data. STUDY DESIGN: Multivariate logistic and "state-dependence" regression models are estimated for survival, ADL functional status, incontinence status, and mental status outcomes from longitudinal residence histories of Medicaid residents spanning 3 to 36 months in length. Outcomes are specified to be a function of resident demographic and diagnostic attributes and facility-level operating and nurse staffing attributes. PRINCIPAL FINDINGS: The estimated parameters for resident demographic and diagnostic attributes showed a great deal of construct validity with respect to clinical expectations regarding risk factors for adverse outcomes. Few facility attributes were associated with outcomes generally, and none was significantly associated with all four outcomes. CONCLUSIONS: The absence of uniform associations between facility attributes and the various long-term care health outcomes studied suggests that strong facility performance on one health outcome may coexist with much weaker performance on other outcomes. This has implications for the aggregation of individual facility performance measures on multiple outcomes and the development of overall outcome performance measures.

Students with learning problems at risk in middle school: stress, social support, and adjustment

Abstract: This study compared the stress, social support, and adjustment of 40 students with learning problems due to learning disabilities or mild mental retardation, and 396 general education students with...

Word Recall in Schizophrenia: A Connectionist Model

Abstract: Objective:The authors examined word recall of patients with schizophrenia by using an experimental paradigm generated from connectionist models of memory.Method:Schizophrenic patients and normal comparison subjects first studied and then recalled a list of 32 words of equal difficulty. Both the connectivity (associative strength) and the network size (number of associates) of the words varied in such a way that the list contained equal proportions of four types of words: 1) high connectivity-small network size, 2) low connectivity-small network size, 3) high connectivity-large network size, and 4) low connectivity-large network size. Results:The schizophrenic patients recalled fewer words and showed a particularly pronounced effect of the connectivity of the to-be-remembered words. For the patients, regardless of network size, recall improved substantially for words of high connectivity and declined dramatically for words of low connectivity. By contrast, the comparison subjects showed the expected effect...

Global Climate Change and Tropical Forest Genetic Resources

Abstract: Global climate change may have a serious impact on genetic resources in tropical forest trees. Genetic diversity plays a critical role in the survival of populations in rapidly changing environments. Furthermore, most tropical plant species are known to have unique ecological niches, and therefore changes in climate may directly affect the distribution of biomes, ecosystems, and constituent species. Climate change may also indirectly affect plant genetic resources through effects on phenology, breeding systems, and plant-pollinator and plant seed disperser interactions, and may reduce genetic diversity and reproductive output. As a consequence, population densities may be reduced leading to reduction in genetic diversity through genetic drift and inbreeding. Tropical forest plants may respond to climate change through phenotypic plasticity, adaptive evolution, migration to suitable site, or extinction. However, the potential to respond is limited by a rapid pace of change and the non-availability of alternate habitats due to past and present trends of deforestation. Thus climate change may result in extinction of many populations and species. Our ability to estimate the precise response of tropical forest ecosystems to climate change is limited by lack of long-term data on parameters that might be affected by climate change. Collection of correlative data from long-term monitoring of climate as well as population and community responses at selected sites offer the most cost-effective way to understand the effects of climate change on tropical tree populations. However, mitigation strategies need to be implemented immediately. Because many effects of climate change may be similar to the effects of habitat alteration and fragmentation, protected areas and buffer zones should be enlarged, with an emphasis on connectivity among conserved landscapes. Taxa that are likely to become extinct should be identified and protected through ex situ conservation programs.

Effects of conditioning on physical fitness and club head speed in mature golfers

Abstract: The purpose of this study was to evaluate the effects of an 8-wk. conditioning program on selected measures of physical fitness and golf performance for 12 male and 5 female recreational golfers (M age = 52.4 yr., SD = 6.7 yr.). Measurements were made at baseline and following the intervention. The twice-per-week program consisted of strength training, flexibility, and plyometric exercises. Analysis of the pre- and posttest scores showed that conditioning was associated with significant increases in muscular strength, flexibility, and club head speed. Without a control group, the data suggest conditioning may be a worthwhile activity for mature golfers.

Extraction and Amplification of Mitochondrial DNA from Formalin-Fixed Deep-Sea Mollusks

Abstract: This work was supported by the Arthritis Foundation post doctoral fellowship (to K.S.V.), a GAANN training grant (to B.M.J.) and National Institutes of Health Grant No. R29 CA58947 (David Skalnik). We would like to thank Drs. David Skalnik, Diana Carlone and Diana Catt for helpful discussions. Address correspondence to Kui Shin Voo, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 W. Walnut Street, Cancer Research Building, Indianapolis, IN 46202-5225, USA. Internet: kvoo@iupui.edu