Self-primed Research Articles

Study Circumstellar Disks Through NIR Interferometry

Thanks to the development of long baseline facilities, near infrared interferometry is becoming an important tool to study the innermost regions of circumstellar proto-planetary disks around close-by pre-main sequence stars. Providing a milli arcsecond spatial resolution and spectroscopic capabilities, the existing interferometers can, for the first time, spatially resolve and separate the gas and dust emission arising form the disk regions where planets are supposed to form, namely inside few Astronomical Units from the central star. The observational limitations and the complexity of the resulting data require however to perform the data analysis in the Fourier space by the comparison with theoretical disk models. To this purpose a number of self consistent radiative transfer models have been recently developed. In this chapter I will first review some of the most recent observational and theoretical results and then, discuss some important future challenges.

Seed abortion in the sexual counterpart of Brachiaria brizantha apomicts (Poaceae)

Gametophytic organization, fertilization and reproductive success are described for the fertile diploid Brachiaria brizantha accession BRA-002747 which is being raised for use in Brachiaria breeding programs, as well as to understand and control of apomixis in this genus. The current paper reports on reproductive biology and analysis of seed set in field experiments during three consecutive years. Unsuccessful seed production in this plant is believed to correlate with early inbreeding depression, based on the reproductive features analyzed. Caryopsis development was observed using differential interference contrast microscopy with seed set determined by the number of self- and open-pollinated pistils that fully developed into viable seeds. Developing and mature female and male gametophytes were observed in the context of flower phenology, morphology and anthesis patterns. Pollen viability was determined by acetocarmine staining and by observation of germination in vivo, which was also used to observe pollen tube/pistil interaction. Although normal development was observed in floral structures, anthesis and gametophytes, seed set was low, with 2 and 6% in self- and open-pollination, respectively, producing seed. Variations observed in the female organs, such as the presence of a hermaphrodite flower in 50% of the inferior floscules and the presence of multiple embryo sacs of the Polygonum type within the same ovule in 15% of the pistils, are not related to low fertility. The majority of pollen grains are viable, in spite of the reduced number of pollen tubes within the style and ovary carpel, and a developing caryopsis was observed in 70% of self-pollinated pistils, indicating successful double fertilization from 2 days after anthesis (DAA). Nevertheless, abortion gradually increased from 2 until 7 DAA and remains elevated until 12 DAA, when caryopsis maturity is achieved. These data confirm low seed set in this accession and indicate that low fertility is not a consequence of abnormalities, either in the floral or gamete structures, or pollen tube rejection, but most likely a consequence of inbreeding depression.

Cognitive Responses to Idealized Media Images of Women: The Relationship of Social Comparison and Critical Processing to Body Image Disturbance in College Women

This study explored college women’s cognitive processing of print advertisements featuring images of highly attractive female models. The relationship of counterarguing (critical processing) and social comparison in response to these images with a number of body image–related variables was examined. Participants were 202 undergraduate females. Research was conducted in two phases. In one phase, participants wrote their thoughts in response to three advertisements taken from recent women’s magazines. In the second phase, women completed a number of self–report measures focusing on body image, along with a number of distracter measures. Results suggest that making negative outcome, upward social comparisons in response to such images is significantly associated with greater internalization of the thin ideal and decreased satisfaction with one’s own appearance. Despite predictions that counterarguing might act as a protective factor, the tendency to generate counterarguments in response to these images was not related to appearance–related dissatisfaction, internalization of the media ideal, or importance of appearance.

Use of the SF-8 to assess health-related quality of life for a chronically ill, low-income population participating in the Central Louisiana Medication Access Program (CMAP)

The utility of the SF-8 for assessing health-related quality of life (HRQL) is demonstrated. Race and gender differences in physical component (PCS) and mental component (MCS) summary scores among participants in the CENLA Medication Access Program (CMAP), along with comparisons to the United States population are made. Age-adjusted multiple linear regression analyses were used to compare 1687 CMAP participants to the US population. Internal race and gender comparisons, adjusting for age and the number of self reported diagnoses, were also obtained. The paired t-test was used to assess 6-month change in PCS and MCS scores for a subset of 342 participants. CMAP participants have PCS and MCS scores that are significantly 10-12 points lower than the US population, indicating lower self-reported HRQL. Females have significantly higher PCS and significantly lower MCS than males. African-Americans have significantly higher MCS than Caucasians. Significant increases in both PCS and MCS were observed for the subset of participants after 6 months of intervention. The expected lower baseline PCS and MCS measures and the expected associations with age and number of diagnoses indicate that the SF-8 survey is an effective tool for measuring the HRQL of participants in this program. Preliminary results indicate significant increases in both PCS and MCS 6 months after intervention.

The Multiplicity of Selves and Selves Management: A Leadership Challenge for the 21st Century

As we move through the stages of our lives, most of us continuously add personal and professional ‘selves’ to a growing list of identities. From infancy to adolescence to adulthood, new selves with various role requirements are added, including friend, lover, co-worker, boss, spouse, and parent. While this rising number of selves impacts every aspect of our existence, few among us plan for their growth in a strategic way. An additional complication is that the mixing of personal and professional roles throughout the day, rather than assigning them to discrete blocks of time, has become increasingly acceptable. Therefore, a primary challenge for leaders is to look beyond the typical boundaries of our public lives and help sub-ordinates develop appropriate synergies among selves that lead to personal and professional success.

Psychopathology and Two Kinds of Narrative Accounts of the Self

The self plays an important role in psycho pathology. Conditions such as dementia raise the question of how much loss of memory and awareness there can be before there is, if ever, also a loss of the self. Syndromes such as Dissociative Identity Disorder (DID) or Multiple Personality Disorder (MPD) raise the possibility of a fragmentation of one self into a number of selves. Depersonalization disorder suggests a kind of diminution both of the sense of self and the reality of the world. Symptoms such as thought insertion suggest a different kind of fragmentation of the coherence of thought within a self.

Statistical Mechanics of Many Interacting Point Masses in Spherical Geometry

The long terms dynamics of point masses in a trapping potential interacting gravitationally cannot be derived from the usual ergodic assumption. The microcanonical partition function diverges for more than two particles because of the large volume allowed in momentum space when the potential energy of a close pair becomes very large negative. In the long term the trajectories explore by diffusion a phase space of infinite volume. This does not say what happens for a large number of self gravitating masses, like the globular clusters or even the galaxies perhaps. I reexamine below this question and try to point out the various difficulties faced by a rational approach. There is a small parameter, the inverse number of masses. At the lowest order in this parameter, the dynamics is given by solutions of the mean field Newton–Vlasov (N–V) kinetic equation. This yields well defined predictions for the steady state under given initial conditions, at least without initial angular momentum, because, besides the usual mechanical invariants, the N–V equation has as an invariant function, the histogram of the probability distribution in phase space. The next step is far more difficult: it requires to take into account the irreversible effects due to ‘collisions’. Actually, these irreversible effects are mostly coming from the resonant interactions between orbits of commensurate or close to commensurate period, not from close pair encounters as usually assumed. The evolution there is the one of slow changes of the steady states of N–V. I discuss briefly the possible solutions on the long time scale linked to the ‘collisions’.

Comparison of the frequency of peptide-specific cytotoxic T lymphocytes restricted by self- and allo-MHC following in vitro T cell priming.

T cell recognition of antigenic peptides is thought to occur preferentially in the context of self-MHC. Here, we have tested the ability of four different K(b)-peptide combinations to stimulate self- and allo-restricted CTL responses in three different mouse stains. Responder T cells were primed in vitro with peptide-loaded stimulator cells, followed by limiting dilution assays to measure the number of peptide-specific cytotoxic T lymphocytes (CTL). For three peptides the number of CTL restricted by self-MHC was higher than for allo-MHC-restricted responses, although the difference was surprisingly small (3- to 5-fold). For the fourth peptide there was no detectable difference in the number of self- and allo-restricted CTL. Peptide titration experiments revealed that high avidity CTL were present in both the self- and allo-restricted setting. These data showed that the bias for preferred peptide recognition in the context of self-MHC imposed by positive thymic selection seems marginal. This raised the possibility that the TCR repertoire is inherently biased towards MHC restriction, independent of MHC-guided thymic selection. This was supported by the analysis of mature T cells generated from the thymus of MHC-deficient mice by lectin stimulation. K(b)-restricted CTL were found amongst these T cells at numbers similar to those of allo-restricted CTL. In summary, the data suggest that MHC-restricted peptide recognition is an inherent feature of the TCR repertoire and does not require thymic selection by MHC molecules.

Glycolipid targets of CD1-mediated T-cell responses.

Members of the CD1 family of antigen-presenting molecules bind and present a variety of mammalian and microbial glycolipids for specific recognition by T cells. CD1 proteins accomplish their antigen-presenting function by binding the alkyl chains of the antigens within a deep, hydrophobic groove on the membrane distal surface of CD1, making the hydrophilic elements of the antigen available for contact with the variable regions of antigen-specific T-cell receptors. Most models of CD1-restricted T cells function in infectious, neoplastic, or autoimmune diseases and are based on the premise that CD1-restricted T-cell responses are initiated by alterations in cellular glycolipid content. Although a growing number of self, altered self and foreign glycolipid antigens have been identified, the cellular mechanisms that could lead to the generation of antigenic glycolipids within cells, or control the presentation of particular classes of altered self or microbial glycolipids in disease states have only recently come under investigation. Here we review the structures of known glycolipid antigens for T cells and discuss how the chemical nature of these antigens, which is quite different from that of peptides, influences their recognition by T cells.

Links between kropotkin' theory of ‘mutual aid’ and the values and practices of action research

The purpose of this article is to outline some of the key ideas of Peter Kropotkin on Mutual Aid, which can be seen to have a resonance and relevance to the value base and practices of action research. Written in 1902 as a refutation of the appropriation of Darwin's theories by social philosophers, Kropotkin's work stresses the importance of cooperation, rather than competition amongst humans as the basis for a creative, supportive and developmental human community (society). His ideas can be seen to have a particular importance or relationship to the growing body of action research in the community health and social care fields, where Kropotkin's theory can also be seen to support and explain the activity of the growing numbers of self help/mutual aid groups in both condition specific groups and in social/community concerns more generally.

Herding cats: modelling Quality of Service for Internet applications

The art and science of tele–traffic modelling is quite mature. On the other hand, Internet traffic seems to defy all attempts to capture its essence in simple models. This is not so surprising when we consider that the Internet consists of a large number of self–organizing systems, each evolved almost independently, which is quite a different way to construct a network than the ground-up design associated with telecommunications. IP routing, TCP congestion control, Relative Transport Protocol playout and loss adaption, Web caching and load balancing, and user behaviour are all involved in a system of massive complexity. In this paper, we survey some of these mechanisms and some of the attempts to bring this unruly bunch of schemes into a more coherent whole. We argue that these attempts are misguided, and that the strength of the Internet design is in the loose organization of these components. As the commercial investors turn their eyes on the Internet with a view to pricing, we argue that they should take extreme care not to propose mechanisms that kill the goose that lays the golden egg. See http://www-mash.cs.berkeley.edu/ns/ for details about the network simulator. National Laboratory for Applied Network Research at http://www.nlanr.net. VBNS Network Topology at http://www.vbns.net/logical.html.

Validity of self reported utilisation of primary health care services in an urban population in Spain

STUDY OBJECTIVETo assess the validity and factors related with the validity of self reported numbers of visits to a primary health care centre, in comparison with the recorded number.DESIGNCross sectional...

Patients’ perception of visual impairment in glaucoma: a pilot study

BACKGROUND/AIMSThere is a paucity of useful information on the level of visual disability suffered by glaucoma patients. The aims of this study were to determine and rank the frequency of...

Evaluation of Dyspnea During Physical and Speech Activities in Patients With Pulmonary Diseases

Dyspnea is most commonly assessed by questioning patients about their subjective perception of shortness of breath during physical exertion. Although speech production is altered by pulmonary disease, it has not been included in current dyspnea assessment tools. A questionnaire was developed to address reports of dyspnea during (1) physical activity, (2) speech activity, and (3) simultaneous speech and physical activity. An equal number of self- and experimenter-administered 30-item questionnaires was given to 203 patients with restrictive and obstructive pulmonary diseases. Their responses were analyzed statistically. The questionnaire had high internal consistency for individual items within each of the three sections. The sections were highly correlated but provided separate and distinct information. Factors extracted from each section were related to severity of dyspnea. Pairwise t tests demonstrated highly significant differences in subject responses to the three sections. The least dyspnea was experienced during speech activities, more during physical activities, and the most when speech and physical activities were combined. The questionnaire proved to be a quickly administered tool for providing information about the effect of dyspnea on activities of daily living. Because of the emphasis on dyspnea during speech production, it may be particularly useful for assessing patients who rely extensively on speaking ability for their livelihood.

Deficits in Source Monitoring in Subjects with Auditory Hallucinations May be Due to Differences in Verbal Intelligence and Verbal Memory

Previous research has proposed that the experience of auditory hallucinations in schizophrenia represents a failure to monitor self-generated verbal mental imagery. However, recent neuropsychological investigations into this matter have provided inconclusive and even contradictory findings with respect to the proposed relationship. This study compared the performance of three groups of adult males, schizophrenic inpatients (hallucinators and nonhallucinators), and normal controls, matched for age, education, and medication, on a source monitoring task. Initial analysis indicated that performance on a Verbal IQ and Verbal Memory test were significantly related to performance on the source monitoring task. Comparisons between groups were made on the basis of state and trait group characteristics with respect to hallucinations. After controlling for the influence of Verbal IQ and Verbal Memory on task performance, no between-group differences were found for overall accuracy in attribution of self-generated items or in the number of self to experimenter misattribution errors. This finding suggests that the inconsistent findings previously noted in this field may be due to a failure to identify and control for these important covariates. The implications of these findings for theoretical models of hallucination are discussed.

No Evidence for Selective Fruit Abortion in the Australian Shrub Grevillea barklyana (Proteaceae)

Plants may increase the average quality of their seed crops by selectively aborting less vigorous progeny when resources are limited. Selective fruit abortion was examined in selfing and outcrossing populations of the Australian proteaceous shrub Grevillea barklyana. Inflorescences were pollinated with cross pollen, self pollen, or a combination of the two pollination types on different flowers. Fruit initiation and maturation were similar on self- and cross-pollinated inflorescences. Self-incompatibility indices indicated that all plants were fully self-compatible. When self and cross fruits competed for limited maternal resources on the same inflorescences, numbers of self and cross fruits did not deviate from a 50:50 ratio. This indicates that differences in the vigor of self and cross progeny were minimal, which may be a consequence of populations having a history of inbreeding. Most fruits aborted early in development, before substantial investment of resources. Results in the selfing and outcrossing populations were similar, indicating that neither selective abortion nor inbreeding depression can account for differences in mating patterns.

Current status of immunologic recurrent pregnancy loss

Normal mammalian pregnancy is confronted with a great number of self (autoimmune) and foreign (alloimmune) antigens that modulate the immune system of the mother. When maternal immune response is affected, recurrent pregnancy loss can result. Recurrent pregnancy loss affects 2% to 5% of reproducing couples. Half of these failures can be explained by genetic, hormonal, infectious, and anatomic factors. Eighty percent of the unexplained failures are proposed to have an immunologic cause. HLA typing, mixed lymphocytotoxic antibody tests, mixed lymphocyte culture reactions, lupus anticoagulant tests, and antiphospholipid antibody determination are methods used to study and differentiate between auto- and alloimmune response. Experimental therapies, including leukocyte immunization, seminal plasma suppositories, intravenous immunoglobulin, aspirin and prednisone, and heparin, have been tried to manage this condition. Results of randomized placebo-controlled clinical trials will aid in the choice of treatment for recurrent pregnancy loss. New assays to diagnose auto- and alloimmune factors in recurrent pregnancy loss are being investigated.

Effects of occupational exposure to mercury vapour on the central nervous system.

Possible effects of mercury on the central nervous system (CNS) were examined in a group of chloralkali workers exposed to mercury (n = 89) and compared with a control group (n = 75), by registration of subjective symptoms, personality changes, forearm tremor, and performance on six computerised psychometric tests in the two groups. The groups were similar in age, education, verbal comprehension, and work tasks. In the chloralkali group, median blood mercury concentration (B-Hg) was 55 nmol/l, serum mercury concentration (S-Hg) 45 nmol/l, and urine mercury concentration (U-Hg) 14.3 nmol/mmol creatinine (25.4 micrograms/g creatinine). Corresponding concentrations in the control group were 15 nmol/l, 4 nmol/l, and 1.1 nmol/mmol creatinine (1.9 micrograms/g creatinine) respectively. The number of self reported symptoms, the scores for tiredness and confusion in the profile of mood states (POMS), and the degree of neuroticism in the Eysenck personality inventory (EPI), were significantly higher in the mercury exposed group compared with the controls. Performance on the psychometric tests and tremor frequency spectra did not differ significantly between the two groups. Dose-response calculations showed weak but statistically significant relations between symptom prevalence and current mercury concentrations in both blood and urine. The performance on three of the psychometric tests was negatively correlated with earlier peak exposures. The findings indicate a slight mercury induced effect on the CNS among the chloralkali workers.

Polyclonal cell activity of a repeat peptide derived from the sequence of an 85-kilodalton surface protein of Trypanosoma cruzi trypomastigotes

Some in vitro and in vivo biological activities of an octadecapeptide derived from an 85-kDa surface protein of Trypanosoma cruzi trypomastigote were studied. The peptide coupled to a carrier protein induced the proliferative response of lymph node cells from mice immunized with various antigens. Moreover, sera from mice immunized with the coupled peptide were found to contain antibodies against a number of self and nonself antigens: fibronectin, bovine serum albumin, myosin, tetanus toxoid, ovalbumin, keyhole limpet hemocyanin, and DNA. These results are discussed in the context of Chagas' disease immunopathology.

Using standardized achievement and oral proficiency tests for self-assessment purposes: the DLIFLC study

While there seems to be enough empirical evidence to substantiate the claim that language learners have the ability to evaluate their own performance, many researchers still feel that self-assessments are rarely as reliable or valid as standard test results or teachers' estimates of their students' linguistic com petence. This skepticism may well be justified, because a large number of self- assessments are based almost entirely on appraisal questionnaires and the use of such instruments without extensive training or preparation is bound to pro duce incorrect evaluations. In the DLIFLC study, however, the experimenter used 'conventional' examinations both for testing purposes and for self- assessment purposes. This method yielded interesting results. It also had limitations, but it generally looked promising.