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In this paper, we study some connections between the polynomial ring
and the differential polynomial ring
. In particular, we answer a question posed by Smoktunowicz, which asks whether
is nil when
is nil, provided that
is an algebra over a field of positive characteristic and
is a locally nilpotent derivation.
OBJECTIVES/SPECIFIC AIMS: To establish an effective team of researchers working towards developing and validating prognostic models employing use of image analyses and other numerical metadata to better understand pediatric undernutrition, and to learn how different approaches can be brought together collaboratively and efficiently. METHODS/STUDY POPULATION: Over the past 18 months we have established a transdisciplinary team spanning three countries and the Schools of Medicine, Engineering, Data Science and Global Health. We first identified two team leaders specifically a pediatric physician scientist (SS) and a data scientist/engineer (DB). The leaders worked together to recruit team members, with the understanding that different ideas are encouraged and will be used collaboratively to tackle the problem of pediatric undernutrition. The final data analytic and interpretative core team consisted of four data science students, two PhD students, an undergraduate biology major, a recent medical graduate, and a PhD research scientist. Additional collaborative members included faculty from Biomedical Engineering, the School of Medicine (Pediatrics and Pathology) along with international Global Health faculty from Pakistan and Zambia. We learned early on that it was important to understand what each of the member’s motivation for contributing to the project was along with aligning that motivation with the overall goals of the team. This made us help prioritize team member tasks and streamline ideas. We also incorporated a mechanism of weekly (monthly/bimonthly for global partners) meetings with informal oral presentations which consisted of each member’s current progress, thoughts and concerns, and next experimental goals. This method enabled team leaders to have a 3600 mechanism of feedback. Overall, we assessed the effectiveness of our team by two mechanisms: 1) ongoing team member feedback, including team leaders, and 2) progress of the research project. RESULTS/ANTICIPATED RESULTS: Our feedback has shown that on initial development of the team there was hesitance in communication due to the background diversity of our various member along with different cultural/social expectations. We used ice-breaking methods such as dedicated time for brief introductions, career directions, and life goals for each team member. We subsequently found that with the exception of one, all other team members noted our working environment professional and conducive to productivity. We also learnt from our method of ongoing constant feedback that at times, due to the complexity of different disciplines, some information was lost due to the difference in educational backgrounds. We have now employed new methods to relay information more effectively, with the use of not just sharing literature but also by explaining the content. The progress of our research project has varied over the past 4-6 months. There was a steep learning curve for almost every member, for example all the data science students had never studied anything related to medicine during their education, including minimal if none exposure to the ethics of medical research. Conversely, team members with medical/biology backgrounds had minimal prior exposure to computational modeling, computer engineering and the verbage of communicating mathematical algorithms. While this may have slowed our progress we learned that by asking questions and engaging every member it was easier to delegate tasks effectively. Once our team reached an overall understanding of each member’s goals there was a steady progress in the project, with new results and new methods of analysis being tested every week. DISCUSSION/SIGNIFICANCE OF IMPACT: We expect that our on-going collaboration will result in the development of new and novel modalities to understand and diagnose pediatric undernutrition, and can be used as a model to tackle several other problems. As with many team science projects, credit and authorship are challenges that we are outlining creative strategies for as suggested by International Committee of Medical Journal Editors (ICMJE) and other literature.
Newborn adiposity, a nutritional measure of the maternal–fetal intra-uterine environment, is representative of future metabolic health. An anthropometric model using weight, length and flank skinfold to estimate neonatal fat mass has been used in numerous epidemiological studies. Air displacement plethysmography (ADP), a non-invasive technology to measure body composition, is impractical for large epidemiological studies. The study objective was to determine the consistency of the original anthropometric fat mass estimation equation with ADP. Full-term neonates were studied at 12–72 h of life with weight, length, head circumference, flank skinfold thickness and ADP measurements. Statistical analyses evaluated three models to predict neonatal fat mass. Lin’s concordance correlation coefficient, mean prediction error and root mean squared error between the predicted and observed ADP fat mass values were used to evaluate the models, where ADP was considered the gold standard. A multi-ethnic cohort of 468 neonates were studied. Models (M) for predicting fat mass were developed using 349 neonates from site 1, then independently evaluated in 119 neonates from site 2. M0 was the original anthropometric model, M1 used the same variables as M0 but with updated parameters and M2 additionally included head circumference. In the independent validation cohort, Lin’s concordance correlation estimates demonstrated reasonable accuracy (model 0: 0·843, 1: 0·732, 2: 0·747). Mean prediction error and root mean squared error in the independent validation was much smaller for M0 compared with M1 and M2. The original anthropometric model to estimate neonatal fat mass is reasonable for predicting ADP, thus we advocate its continued use in epidemiological studies.
The ‘DOHaD’ literature argues that stressors encountered at age t ‘program’ individual health at age t+n, and that this programming appears strongest when t defines critical developmental periods including gestation. Accordingly, children of ill-nourished pregnant women suffer greater later life morbidity than do offspring of well-nourished mothers. The possibility that circumstances other than access to nutritious food drive both a mother’s diet and fetal development remains, however, a threat to the inference of programming in utero. Attempts to rule out this threat include tests of the hypothesis that birth cohorts in gestation during famines exhibit shorter life spans than other cohorts. The tests produce conflicting results attributed to confounding by autocorrelation, selective migration and introduction of modern medicine. We offer a test in which neither medicine nor migration nor autocorrelation could obscure the presumed effect. We apply time-series regression methods to the life span of Swedes born between 1751 and 1800 to test the hypothesis that cohorts exposed in utero to the Swedish Famine of 1773 lived shorter lives than expected from trends and other forms of autocorrelation. We use these 50 birth cohorts not only because they included those exposed to severe famine but also because they may well be the only human birth cohorts that completed life unaffected by selective migration and unaided by modern medicine and for which we know life span. We find that the cohort born in 1773 live 4.2 years longer than expected from trends over the last half of the 18th century.
Hydatigera (Cestoda: Taeniidae) is a recently resurrected genus including species seldom investigated in sub-Saharan Africa. We surveyed wild small mammal populations in the areas of Richard Toll and Lake Guiers, Senegal, with the objective to evaluate their potential role as intermediate hosts of larval taeniid stages (i.e. metacestodes). Based on genetic sequences of a segment of the mitochondrial DNA gene cytochrome c oxidase subunit 1 (COI), we identified Hydatigera parva metacestodes in 19 out of 172 (11.0%) Hubert's multimammate mice (Mastomys huberti) and one out of six (16.7%) gerbils (Taterillus sp.) and Hydatigera taeniaeformis sensu stricto metacestodes in one out of 215 (0.5%) Nile rats (Arvicanthis niloticus). This study reports epidemiological and molecular information on H. parva and H. taeniaeformis in West African rodents, further supporting the phylogeographic hypothesis on the African origin of H. parva. Our findings may indicate significant trophic interactions contributing to the local transmission of Hydatigera spp. and other parasites with similar life-cycle mechanisms. We therefore propose that further field investigations of rodent population dynamics and rodent-borne infectious organisms are necessary to improve our understanding of host–parasite associations driving the transmission risks of rodent parasites in West Africa.
We report on the first successful coordinated observations of stellar flares carried out on March 28, 1984 simultaneously over a wide range of wavelengths, from UV to microwaves, using the IUE satellite, three ESO telescopes at La Silla (Chile) and the VLA at Socorro (NM, USA).
We here propose a new kinematic picture of central Sicily based on the results of detailed field mapping of the region, combined with structural analyses and the interpretation of the available literature subsurface data. Our study focused on the tectonic boundary of a structural depression, the Caltanissetta Trough, which is now filled with allochthonous terrains resting on the deep-seated inverted African palaeomargin units. Our data refer to the tectonosedimentary evolution of the thrust-top basins, from Late Tortonian to Quaternary times. The study points out the occurrence of regional E–W-oriented dextral shear zones, cutting the NE-oriented trends of the thrust belt. This new evidence would confirm the major role of the E–W trend in the tectonic inversion of the external portions of the Africa palaeomargin in Sicily. Our results could contribute to a better understanding of the location in Sicily of the tectonic lineaments accommodating the hundreds of kilometres of lateral displacement, caused by the Late Miocene–Quaternary Tyrrhenian Basin opening to the north of the island.
The Peloritani Mountains, in the southern part of the Calabrian Terranes, southern Italy, have been classically interpreted as the product of the Paleogene brittle deformation of the European continental back-stop of the Neotethyan subduction complex. This reconstruction conflicts with the occurrence of an Alpine metamorphic overprint that affected portions of both the Variscan metamorphic units and part of the Mesozoic sedimentary covers of the mountain belt. New field data, integrated with petrographic, micro- and meso-structural analyses and stratigraphic investigation of the syn-tectonic terrigenous covers, well constrain a Paleogene collision event along the Africa–Nubia convergent margin that caused the exhumation of the Alpine metamorphic units of the Peloritani Mountains. The syn-collisional exhumation was associated with shearing along two major Africa-verging crustal thrusts arising from the positive tectonic inversion of the former European palaeomargin. Early tectonic motions occurred within the mountain belts and produced the exhumation of the external portions of the edifice. Later tectonic motions occurred along the sole-thrust of the entire edifice and caused the definitive exhumation of the entire mountain belt. The whole crustal thrusting lasted for a period of c. 10 Ma, during the entire Oligocene. The definitive southwestward emplacement of the Peloritani Mountain Belt onto the Neotethyan accretionary wedge was followed by two Late Oligocene – Early Miocene NW–SE-oriented right lateral shear zones, replacing the previous crustal thrust. These two strike-slip belts are interpreted as the surface expression of the deep-seated suture zone between the colliding Africa and Europe continental crusts.
I prophylaxis is the most effective strategy to eradicate I deficiency disorders, but it has been shown to affect the thyroid disease pattern. In this study, we assessed the frequency of thyroid disorders in an adult population living in two areas of southern Italy after implementing I prophylaxis. To this aim, a cross-sectional, population-based study including 489 subjects from an I-deficient rural and an I-sufficient urban area of southern Italy was conducted. Thyroid ultrasound was performed on all participants, and urine and blood samples were collected from each subject. The levels of thyroid-stimulating hormone (TSH), thyroglobulin (TgAb) and thyroperoxidase antibodies (TPOAb), urinary I excretion (UIE), and thyroid volume and echogenicity were evaluated. We found that the median UIE was higher in the urban than in the rural area (P=0·004), whereas the prevalence of subjects affected by goitre was higher in the rural compared with the urban area (P=0·003). Positive TgAb rather than TPOAb were more frequent in subjects from the urban area compared with the rural area (P=0·009). The hypoechoic pattern at thyroid ultrasound (HT-US) was similar between the two areas, but TgAb were significantly higher (P=0·01) in HT-US subjects from the urban area. The frequency of elevated TSH did not differ between the two screened populations, and no changes were found for TgAb positivity in subjects with high TSH in the urban compared with the rural area. Our findings support that the small risks of I supplementation are far outweighed by the substantial benefits of correcting I deficiency, although continued monitoring of populations is necessary.
Emerging theory and empirical work suggest that the ‘Bruce Effect’, or the increase in spontaneous abortion observed in non-human species when environments become threatening to offspring survival, may also appear in humans. We argue that, if it does, the effect would appear in the odds of twins among male and female live births. We test the hypothesis, implied by our argument, that the odds of a twin among male infants in Norway fell below, while those among females rose above, expected levels among birth cohorts in gestation in July 2011 when a deranged man murdered 77 Norwegians, including many youths. Results support the hypothesis and imply that the Bruce Effect operates in women to autonomically raise the standard of fetal fitness necessary to extend the gestation of twins. This circumstance has implications for using twins to estimate the relative contributions of genes and environment to human responses to exogenous stimuli.
This study examines the interplay between individual and social–developmental factors in the development of positive functioning, substance use problems, and mental health problems. This interplay is nested within positive and negative developmental cascades that span childhood, adolescence, the transition to adulthood, and adulthood. Data are drawn from the Seattle Social Development Project, a gender-balanced, ethnically diverse community sample of 808 participants interviewed 12 times from ages 10 to 33. Path modeling showed short- and long-term cascading effects of positive social environments, family history of depression, and substance-using social environments throughout development. Positive family social environments set a template for future partner social environment interaction and had positive influences on proximal individual functioning, both in the next developmental period and long term. Family history of depression adversely affected mental health functioning throughout adulthood. Family substance use began a cascade of substance-specific social environments across development, which was the pathway through which increasing severity of substance use problems flowed. The model also indicated that adolescent, but not adult, individual functioning influenced selection into positive social environments, and significant cross-domain effects were found in which substance-using social environments affected subsequent mental health.
Studies have demonstrated that the effects of two well-known predictors of adolescent substance use, family monitoring and antisocial peers, are not static but change over the course of adolescence. Moreover, these effects may differ for different groups of youth. The current study uses time-varying effect modeling to examine the changes in the association between family monitoring and antisocial peers and marijuana use from ages 11 to 19, and to compare these associations by gender and levels of behavioral disinhibition. Data are drawn from the Raising Healthy Children study, a longitudinal panel of 1,040 youth. The strength of association between family monitoring and antisocial peers and marijuana use was mostly steady over adolescence, and was greater for girls than for boys. Differences in the strength of the association were also evident by levels of behavioral disinhibition: youth with lower levels of disinhibition were more susceptible to the influence of parents and peers. Stronger influence of family monitoring on girls and less disinhibited youth was most evident in middle adolescence, whereas the stronger effect of antisocial peers was significant during middle and late adolescence. Implications for the timing and targeting of marijuana preventive interventions are discussed.
Systematic photometric monitoring of active RS CVn binaries carried out at Catania with the automatic telescope APT-80, is being complemented with Hα low- and high-resolution spectroscopy. The relationship between photospheric and chromospheric activity is investigated in order to shed light into the complex three-dimensional structure of surface activity. Preliminary results on the photometric and Hα monitoring of the active binaries, UX Ari, RS CVn, BM CVn, HK Lac, IM Peg, V 711 Tau, and EI Eri, are here reported.
We report the discovery of the first low–mass pre–main sequence eclipsing binary among a sample of double-lined spectroscopic binaries in the Orion star forming region found in a previous high-resolution spectroscopic investigation on ROSAT–discovered weak-T Tauri stars. Here we present the preliminary results from the combined analysis of the spectroscopic orbit and B and V light–curves, using data available till spring 2000. We then compare the fundamental stellar parameters derived from the orbital solution with those inferred from some widely used theoretical evolutionary models.