1,664 research outputs found
Effect of nucleon exchange on projectile multifragmentation in the reactions of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon
Multifragmentation of quasiprojectiles was studied in reactions of 28Si beam
with 112Sn and 124Sn targets at projectile energies 30 and 50 MeV/nucleon. The
quasiprojectile observables were reconstructed using isotopically identified
charged particles with Z_f <= 5 detected at forward angles. The nucleon
exchange between projectile and target was investigated using isospin and
excitation energy of reconstructed quasiprojectile. For events with total
reconstructed charge equal to the charge of the beam (Z_tot = 14) the influence
of beam energy and target isospin on neutron transfer was studied in detail.
Simulations employing subsequently model of deep inelastic transfer,
statistical model of multifragmentation and software replica of FAUST detector
array were carried out. A concept of deep inelastic transfer provides good
description of production of highly excited quasiprojectiles. The isospin and
excitation energy of quasiprojectile were described with good overall
agreement. The fragment multiplicity, charge and isospin were reproduced
satisfactorily. The range of contributing impact parameters was determined
using backtracing procedure.Comment: 11 pages, 8 Postscript figures, LaTeX, to appear in Phys. Rev. C (
Dec 2000
Adaptive Markets and the New World Order
In the adaptive markets hypothesis (AMH) intelligent but fallible investors learn from and adapt to changing economic environments. This implies that markets are not always efficient but are usually competitive and adaptive, varying in their degree of efficiency as the environment and investor population change over time. The AMH has several implications, including the possibility of negative risk premiums, alpha converging to beta, and the importance of macro factors and risk budgeting in asset allocation policies
A Three-Dimensional Atlas of the Honeybee Neck
Three-dimensional digital atlases are rapidly becoming indispensible in modern biology. We used serial sectioning combined with manual registration and segmentation of images to develop a comprehensive and detailed three-dimensional atlas of the honeybee head-neck system. This interactive atlas includes skeletal structures of the head and prothorax, the neck musculature, and the nervous system. The scope and resolution of the model exceeds atlases previously developed on similar sized animals, and the interactive nature of the model provides a far more accessible means of interpreting and comprehending insect anatomy and neuroanatomy
Cluster Interpretation of Properties of Alternating Parity Bands in Heavy Nuclei
The properties of the states of the alternating parity bands in actinides,
Ba, Ce and Nd isotopes are analyzed within a cluster model. The model is based
on the assumption that cluster type shapes are produced by the collective
motion of the nuclear system in the mass asymmetry coordinate. The calculated
spin dependences of the parity splitting and of the electric multipole
transition moments are in agreement with the experimental data.Comment: 29 pages, 10 figure
Inhomogeneous isospin distribution in the reactions of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon
We have created quasiprojectiles of varying isospin via peripheral reactions
of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon. The quasiprojectiles have
been reconstructed from completely isotopically identified fragments. The
difference in N/Z of the reconstructed quasiprojectiles allows the
investigation of the disassembly as a function of the isospin of the
fragmenting system. The isobaric yield ratio 3H/3He depends strongly on N/Z
ratio of quasiprojectiles. The dependences of mean fragment multiplicity and
mean N/Z ratio of the fragments on N/Z ratio of the quasiprojectile are
different for light charged particles and intermediate mass fragments.
Observation of a different N/Z ratio of light charged particles and
intermediate mass fragments is consistent with an inhomogeneous distribution of
isospin in the fragmenting system.Comment: 5 pages, 4 Postscript figures, RevTe
Inhibitory Control Predicts Grammatical Ability
We present evidence that individual variation in grammatical ability can be predicted by individual variation in inhibitory control. We tested 81 5-year-olds using two classic tests from linguistics and psychology (Past Tense and the Stroop). Inhibitory control was a better predicator of grammatical ability than either vocabulary or age. Our explanation is that giving the correct response in both tests requires using a common cognitive capacity to inhibit unwanted competition. The implications are that understanding the developmental trajectory of language acquisition can benefit from integrating the developmental trajectory of non-linguistic faculties, such as executive control
Patient and physician satisfaction in an observational study with methyl aminolevulinate daylight-photodynamic therapy in the treatment of multiple actinic keratoses of the face and scalp in 6 European countries
BACKGROUND
Guidelines recommend treating actinic keratoses (AKs) as they are recognized as precursors of invasive squamous cell carcinoma.
OBJECTIVE
The objective of this study was to collect real-world clinical data on the use of methyl aminolevulinate daylight photodynamic therapy (MAL DL-PDT) for the treatment of face and scalp AK in Europe.
METHODS
A prospective, multicenter, non-interventional study was conducted in six European countries in patients receiving a single treatment of MAL DL-PDT for face and/or scalp AK. Patient-reported outcomes were assessed by patient questionnaires at baseline and at 3 months after treatment, efficacy was assessed at 3 months using a 6-point global improvement scale, and adverse events (AE) were recorded at each visit.
RESULTS
Overall, 325 patients were enrolled from 52 investigational centres, 314 of whom attended the 3-month visit. Most patients had multiple lesions (58.4% had >10 lesions) with lesions mainly located on the scalp (60.0%) and/or forehead (54.2%). AKs were predominantly grade I (39.4%) or grade II (33.2%), and 10.5% of patients had grade III lesions. The proportions of patients and physicians that were overall satisfied to very satisfied with the MAL DL-PDT treatment were 80.4% and 90.3%, respectively. The vast majority of patients (90.0%) would consider using MAL DL-PDT again if needed. Physician-assessed efficacy at 3 months was at least much improved in 83.5% of patients, with 45.9% of patients requiring no retreatment. Related AEs were reported in 15% of patients.
CONCLUSION
Use of MAL DL-PDT for multiple face and/or scalp AKs resulted in high levels of patient and physician satisfaction in clinical practice in Europe, reflecting the good efficacy and high tolerability of this convenient procedure
The changing role of pre-admission work experience (clinical visits) in Therapeutic Radiography, Diagnostic Radiography and Operating Department Practice: Student perspectives (Part 1)
Introduction
Clinical visits (work experience opportunities) are a recommended part of admissions processes for many diagnostic and therapeutic radiography courses but not for operating department practice (ODP) where observational visits are challenging for applicants to obtain. The Covid-19 pandemic interrupted access to visits for all prospective students; this study presents a review of the value of clinical visits and alternatives.
Methods
This article reports the initial qualitative phase of a three-phase mixed methods study. Using a critical realist approach, focus groups explored first year student experiences of the ‘ideal’ pre-admission clinical visit and alternative resources. A structured review of Online Prospectus (OLP) entries was undertaken by two student researchers to ascertain the requirements for clinical visits for the three professions.
Results
Four focus groups included 25 first year students interviewed prior to their first clinical placement (14 therapeutic radiography, 5 diagnostic radiography and 6 ODP students). Three themes were constructed, namely: informing career choices, the clinical visit experience, and the value of clinical visits. Clinical visits affirmed rather than inspired career choices. The best timing for a visit was before admission interviews and optimal duration was a full day. Interacting with current students was the most valued aspect. Videos and simulations provided in-depth information about the professional role and allowed replay, but some participants found the videos uninspiring. OLP entries present a confusing picture for applicants who may be researching several Universities and professions.
Conclusion
Clinical visits were deemed ‘vital’ to radiography student career choices, yet ODPs who could not access visits were comfortable with videos. Simulated visits are a safe option amidst the pandemic but must capture the dynamic and patient-centred nature of practice to accurately inform career choices
The price of rapid exit in venture capital-backed IPOs
This paper proposes an explanation for two empirical puzzles surrounding initial public offerings (IPOs). Firstly, it is well documented that IPO underpricing increases during “hot issue” periods. Secondly, venture capital (VC) backed IPOs are less underpriced than non-venture capital backed IPOs during normal periods of activity, but the reverse is true during hot issue periods: VC backed IPOs are more underpriced than non-VC backed ones. This paper shows that when IPOs are driven by the initial investor’s desire to exit from an existing investment in order to finance a new venture, both the value of the new venture and the value of the existing firm to be sold in the IPO drive the investor’s choice of price and fraction of shares sold in the IPO. When this is the case, the availability of attractive new ventures increases equilibrium underpricing, which is what we observe during hot issue periods. Moreover, I show that underpricing is affected by the severity of the moral hazard problem between an investor and the firm’s manager. In the presence of a moral hazard problem the degree of equilibrium underpricing is more sensitive to changes in the value of the new venture. This can explain why venture capitalists, who often finance firms with more severe moral hazard problems, underprice IPOs less in normal periods, but underprice more strongly during hot issue periods. Further empirical implications relating the fraction of shares sold and the degree of underpricing are presented
Neurology
Contains reports on six research projects.U. S. Public Health Service (B-3055-4, B-3090-4, MH-06175-02)U. S. Air Force (AF49(638)-1313)U.S. Navy. Office of Naval Research (Nonr-1841(70)
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