708 research outputs found
On generating functions in additive number theory, II: Lower-order terms and applications to PDEs
We obtain asymptotics for sums of the form
involving lower order main terms. As an application, we show that for almost
all one has
and that in a suitable sense this is best possible. This allows us to improve
bounds for the fractal dimension of solutions to the Schr\"odinger and Airy
equations
Prospectus, September 24, 1980
RODNEY DANGERFIELD GETS SOME RESPECT FROM PC; PCF group greets newcomers; Parkland offers COSMOS telecourse; Clerks to be on campus to register voters; Women\u27s Program discusses importance of adequate diet; Breakdown of budget: Where does all your money go?; Women\u27s Program presents last of self-care series; Parkland College Board of Trustees meets; Members needed; A friend is someone who...; Family Life Program offers Living in Step ; Chimera Inc. offers workshop; PACT presents seminar for expectant parents; Steve Goodman: A talented performer; The Ducks have a good time; Rodney Dangerfield: I don\u27t get no respect; He will always get respect in Champaign-Urbana ; Francis named Outstanding Young Men of America ; Eisner to hold celebration; Classifieds; Showcase and workshop Oct. 8; PACT presents program: Early childhood; Volleyballers win two; Upsets spoil Fast Freddy; All you lost freshman-- pay attention to this story; Fast Freddy Contesthttps://spark.parkland.edu/prospectus_1980/1020/thumbnail.jp
Discovery and Orbital Determination of the Transient X-ray Pulsar GRO J1750-27
We report on the discovery and hard X-ray (20-70 keV) observations of the 4.45 s period transient X-ray pulsar GRO J1750-27 with the BATSE all-sky monitor on board CGRO. A relatively faint outburst (<30 mcrab peak) lasting at least 60 days was observed during which the spin-up rate peaked at
38 pHz s^(-1) and was correlated with the pulsed intensity. An orbit with a period of 29.8 days was found. The large spin-up rate, spin period, and orbital period together suggest that accretion is occurring from a disk and that the outburst is a "giant" outburst typical of a Be/X-ray transient system. No optical counterpart has yet been reported
Prospectus, October 1, 1980
HAVE YOU REGISTERED TO VOTE YET? REGISTER THE PAINLESS WAY--ON CAMPUS; Election \u2780: The man behind the woman; Handicrafts taught to senior citizens; Got a pet peeve, gripe, or opinion? Write PROSPECTUS\u27 editor!; MMWW gives calendar of topics; Make Christmas gift decorations now; Student Government will hold O.RG.I.I. in Lounge; Record Enrollment: Fall enrollment sets new record; Activities set for Society; Insurance offered; No overdubbing results in very, very good record; Letters to the editor: Student wants late breakfast; Our Mistake!; Urbana student wins PC faculty wives\u27 $200; Park district has youth fall classes; Give Blood Today; Science You Can See: The chemistry of photography; Parkland student reps needed for committees; New officers named for Parkland\u27s PATH; Children\u27s art exhibit to be Oct. 4, 9-9, Market Place Mall; Arts activities and events need co-sponsors; PLATO proves very popular; Peptic ulcers October 7 topic; PCF to hear Christian teachers; Need it? Financial aid still available; CPA Accounting Careers Conference to be Nov. 15; Classifieds; Football/tennis intermurals begin; Champaign Park District organizes basketball league; PC Datebook; Jeff Dodson places second in LT gold invitational; Women\u27s V-ball record upped; PC baseball player wins; Gal Friday tries predicting; Fast Freddy Contesthttps://spark.parkland.edu/prospectus_1980/1019/thumbnail.jp
Torque Reversal and Spin-Down of the Accretion-Powered Pulsar 4U 1626-67
Over 5 yr of hard X-ray (20-60 keV) monitoring of the 7.66 s accretion-powered pulsar 4U 1626-67 with the Compton Gamma Ray Observatory/BATSE large-area detectors has revealed that the neutron star is now steadily spinning down, in marked contrast to the steady spin-up observed during 1977-1989. This is the second accreting pulsar (the other is GX 1+4) that has shown extended, steady intervals of both spin-up and spin-down. Remarkably, the magnitudes of the spin-up and spin-down torques differ by only 15%, with the neutron star spin changing on a timescale |ν/dot ν| ≈ 5000 yr in both states. The current spin-down rate is itself decreasing on a timescale |dot ν/bar ν| ≈ 26 yr. The long-term timing history shows small-amplitude variations on a 4000 day timescale, which are probably due to variations in the mass transfer rate. The pulsed 20-60 keV emission from 4U 1626-67 is well-fitted by a power-law spectrum with photon index γ = 4.9 and a typical pulsed intensity of 1.5 × 10^(-10) ergs cm^(-2) s^(-1). The low count rates with BATSE prohibited us from constraining the reported 42 minute binary orbit, but we can rule out long-period orbits in the range 2 days lesssim Porb lesssim 900 days.
We compare the long-term torque behavior of 4U 1626-67 to other disk-fed accreting pulsars and discuss the implications of our results for the various theories of magnetic accretion torques. The abrupt change in the sign of the torque is difficult to reconcile with the extremely smooth spin-down now observed. The strength of the torque noise in 4U 1626-67, ~10^(-22) Hz^2 s^(-2) Hz^(-1), is the smallest ever measured for an accreting X-ray pulsar, and it is comparable to the timing noise seen in young radio pulsars. We close by pointing out that the core temperature and external torque (the two parameters potentially relevant to internal sources of timing noise) of an accreting neutron star are also comparable to those of young radio pulsars
Manipulation of an Innate Escape Response in Drosophila: Photoexcitation of acj6 Neurons Induces the Escape Response
Background: The genetic analysis of behavior in Drosophila melanogaster has linked genes controlling neuronal connectivity and physiology to specific neuronal circuits underlying a variety of innate behaviors. We investigated the circuitry underlying the adult startle response, using photoexcitation of neurons that produce the abnormal chemosensory jump 6 (acj6) transcription factor. This transcription factor has previously been shown to play a role in neuronal pathfinding and neurotransmitter modality, but the role of acj6 neurons in the adult startle response was largely unknown. Principal Findings: We show that the activity of these neurons is necessary for a wild-type startle response and that excitation is sufficient to generate a synthetic escape response. Further, we show that this synthetic response is still sensitive to the dose of acj6 suggesting that that acj6 mutation alters neuronal activity as well as connectivity and neurotransmitter production. Results/Significance: These results extend the understanding of the role of acj6 and of the adult startle response in general. They also demonstrate the usefulness of activity-dependent characterization of neuronal circuits underlying innat
The European Transdisciplinary Assessment of Climate Engineering (EuTRACE): Removing Greenhouse Gases from the Atmosphere and Reflecting Sunlight away from Earth
The European Transdisciplinary Assessment of Climate Engineering (EuTRACE): Removing Greenhouse Gases from the Atmosphere and Reflecting Sunlight away from Eart
The influence of allogenic blood transfusion in patients having free-flap primary surgery for oral and oropharyngeal squamous cell carcinoma
The influence of perioperative blood transfusion in oral and oropharyngeal squamous cell carcinoma remains uncertain. It is believed that blood transfusion downregulates the immune system and may have an influence on cancer recurrence and survival. In all, 559 consecutive patients undergoing primary surgery for oral and oropharyngeal squamous cell carcinoma between 1992 and 2002 were included in this study. Known prognostic variables along with transfusion details were obtained from head and neck cancer and blood transfusion service databases, respectively. Adjusting for relevant prognostic factors in Cox regression, the hazard ratio for patients having 3 or more transfused units relative to those not transfused was 1.52 (95% confidence interval (CI) 0.93–2.47) for disease-specific and 1.52 (95% CI 1.05–2.22) for overall mortality. Blood transfusion of 3 or more units might confer a worse prognosis in patients undergoing primary surgery for oral and oropharyngeal squamous cell carcinoma. Therefore, every effort should be made to limit the amount of blood transfused to the minimum requirement
Tourism as connectedness.
Late modernity in developed nations is characterized by changing social and psychological conditions, including individualization, processes of competition and loneliness. Remaining socially connected is becoming increasingly important. In this situation, travel provides meaning through physical encounters, inclusion in traveller Gemeinschaft based on shared norms, beliefs and interests, and social status in societies increasingly defined by mobilities. As relationships are forged and found in mobility, travel is no longer an option, rather a necessity for sociality, identity construction, affirmation or alteration. Social contexts and the underlying motivations for tourism have changed fundamentally in late modernity: non-tourism has become a threat to self-conceptions. By integrating social and psychological perspectives, this paper expands and deepens existing travel and mobilities discussions to advance the understanding of tourism as a mechanism of social connectedness, and points to implications for future tourism research
Molecular epidemiology of pneumococci obtained from Gambian children aged 2–29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine
BACKGROUND: The study describes the molecular epidemiology of Streptococcus pneumoniae causing invasive disease in Gambian children METHODS: One hundred and thirty-two S. pneumoniae isolates were recovered from children aged 2-29 months during the course of a pneumococcal conjugate vaccine trial conducted in The Gambia of which 131 were characterized by serotyping, antibiotic susceptibility, BOX-PCR and MLST. RESULTS: Twenty-nine different serotypes were identified; serotypes 14, 19A, 12F, 5, 23F, and 1 were common and accounted for 58.3% of all serotypes overall. MLST analysis showed 72 sequence types (STs) of which 46 are novel. eBURST analysis using the stringent 6/7 identical loci definition, grouped the isolates into 17 clonal complexes and 32 singletons. The population structure of the 8 serotype 1 isolates obtained from 4 vaccinated and 2 unvaccinated children were the same (ST 618) except that one (ST3336) of the isolates from an unvaccinated child had a novel ST which is a single locus variant of ST 618. CONCLUSION: We provide the first background data on the genetic structure of S. pneumoniae causing IPD prior to PC7V use in The Gambia. This data will be important for assessing the impact of PC7V in post-vaccine surveillance from The Gambia
- …