472 research outputs found
The Effect of Macro Information Environment Change on the Quality of Management Earnings Forecasts
The 1990s were characterized by substantial increases in the performance of and investor reliance on financial analysts. Because managers possess superior private information and issue forecasts to align investors’ expectations with their own, we predict that managers increased the quality of their earnings forecasts during the 1990s in order to keep pace with the improved forward-looking information provided by financial analysts, upon which investors increasingly relied. Using a sample of 2,437 management earnings forecasts, we document an increase in management earnings forecast precision, management earnings forecast accuracy, and managers’ tendency to explain earnings forecasts in 1993-1996 relative to 1983-1986. Given that these forecast characteristics are linked to greater informativeness and credibility, we also document that the information content of management earnings forecasts, as measured by the strength of share price responses to forecast news, increased in 1993 -1996 relative to 1983-1986. As expected, the increased information content of management forecasts primarily occurred for firms covered by financial analysts
The ExaVolt Antenna: A Large-Aperture, Balloon-embedded Antenna for Ultra-high Energy Particle Detection
We describe the scientific motivation, experimental basis, design
methodology, and simulated performance of the ExaVolt Antenna (EVA) mission,
and planned ultra-high energy (UHE) particle observatory under development for
NASA's suborbital super-pressure balloon program in Antarctica. EVA will
improve over ANITA's integrated totals - the current state-of-the-art in UHE
suborbital payloads - by 1-2 orders of magnitude in a single flight. The design
is based on a novel application of toroidal reflector optics which utilizes a
super-pressure balloon surface, along with a feed-array mounted on an inner
membrane, to create an ultra-large radio antenna system with a synoptic view of
the Antarctic ice sheet below it. Radio impulses arise via the Askaryan effect
when UHE neutrinos interact within the ice, or via geosynchrotron emission when
UHE cosmic rays interact in the atmosphere above the continent. EVA's
instantaneous antenna aperture is estimated to be several hundred square meters
for detection of these events within a 150-600 MHz band. For standard
cosmogenic UHE neutrino models, EVA should detect of order 30 events per flight
in the EeV energy regime. For UHE cosmic rays, of order 15,000 geosynchrotron
events would be detected in total, several hundred above 10 EeV, and of order
60 above the GZK cutoff energyComment: 20 pages, 14 figures; introductory section shortened; additional
horizontal polarization simulation results included. In final review for
Astroparticle Physic
The anatomical landmarks effective in the localisation of the median nerve during orthopaedic procedures
Background: The aim of this study was to create a safe zone for surgeons who perform procedures in the wrist to avoid iatrogenic damage to the median nerve (MN) by identifying anatomical landmarks using ultrasound (USG).Materials and methods: We measured the distances between the MN and two easily identifiable anatomical landmarks at the level of the proximal border of carpal ligament using USG.Results: A total of 57 volunteers (n = 114 upper limbs) were included in this study. Our main findings revealed that the distance from the flexor carpi radialis tendon to MN (FCR-MN) was 7.87 mm (95% confidence interval 7.37–8.37) and the distance from flexor carpi ulnaris tendon to MN (FCU-MN) was 19.09 mm (95% confidence interval 18.51–19.67).Conclusions: The tendons of FCR and FCU are easily identifiable landmarks that can be distinguished using simple palpation. Based on our USG findings, the area around FCR should be carefully navigated to avoid iatrogenic injury to the MN during surgical procedures around the carpal tunnel
An anatomical investigation of rare upper limb neuropathies due to the Struthers’ ligament or arcade: a meta-analysis
Background: The Struthers’ ligament (SL) is a fibrous band that originates fromthe supracondylar humeral process and inserts into the medial humeral epicondyle, potentially compressing both the median nerve and brachial artery. The controversial Struthers’ arcade (SA) is a musculotendinous band found in the distal end of the arm that might compress the ulnar nerve. This study aimed to evaluate the pooled prevalence estimate of the SL and SA, and their anatomical features. Materials and methods: A meticulous search of major electronic medical databases was carried out regarding both structures. Applicable articles (and all relevant references) were analysed. Data from the eligible articles was extracted and evaluated. The quality and the potential risk of bias in the included studies were assessed using the AQUA tool. Results: The arcade was reported in 13 studies (510 arms), whereas the ligament in 6 studies (513 arms). The overall pooled prevalence estimate of the ligament was 1.8%, and 52.6% for the arcade. Most frequently, the ulnar nerve was covered by a tendinous arcade (42.2%). In all cases, the ligament inserted into the medial humeral epicondyle, but had various origins. Only 1 study reported compression of the median nerve by the ligament, whilst another contradicted this view. Conclusions: Although the SL is rare, and the SA is a valid anatomical entity (though with a variable presentation), clinically meaningful neurovascular entrapments caused by these structures are infrequent. Nonetheless, a better understanding of each may be beneficial for the best patient outcomes
Log D<sub>7.4</sub> and plasma protein binding of synthetic cannabinoid receptor agonists and a comparison of experimental and predicted lipophilicity
The emergence of new synthetic cannabinoid receptor agonists (SCRAs) onto the illicit drugs market continues to cause harm, and the overall availability of physicochemical and pharmacokinetic data for new psychoactive substances is lacking. The lipophilicity of 23 SCRAs and the plasma protein binding (PPB) of 11 SCRAs was determined. Lipophilicity was determined using a validated chromatographic hydrophobicity index (CHI) log D method; tested SCRAs showed moderate to high lipophilicity, with experimental log D7.4 ranging from 2.48 (AB-FUBINACA) to 4.95 (4F-ABUTINACA). These results were also compared to in silico predictions generated using seven commercially available software packages and online tools (Canvas; ChemDraw; Gastroplus; MoKa; PreADMET; SwissADME; and XlogP). Licenced, dedicated software packages provided more accurate lipophilicity predictions than those which were free or had prediction as a secondary function; however, the latter still provided competitive estimates in most cases. PPB of tested SCRAs, as determined by equilibrium dialysis, was in the upper range of the lipophilicity scale, ranging from 90.8% (ADB-BUTINACA) to 99.9% (BZO-HEXOXIZID). The high PPB of these drugs may contribute to reduced rate of clearance and extended durations of pharmacological effects compared to lesser-bound SCRAs. The presented data improve understanding of the behaviour of these drugs in the body. Ultimately, similar data and predictions may be used in the prediction of the structure and properties of drugs yet to emerge on the illicit market
Structural basis of a redox-dependent conformational switch that regulates the stress kinase p38α
Many functional aspects of the protein kinase p38α have been illustrated by more than three hundred structures determined in the presence of reducing agents. These structures correspond to free forms and complexes with activators, substrates, and inhibitors. Here we report the conformation of an oxidized state with an intramolecular disulfide bond between Cys119 and Cys162 that is conserved in vertebrates. The structure of the oxidized state does not affect the conformation of the catalytic site, but alters the docking groove by partially unwinding and displacing the short αD helix due to the movement of Cys119 towards Cys162. The transition between oxidized and reduced conformations provides a mechanism for fine-tuning p38α activity as a function of redox conditions, beyond its activation loop phosphorylation. Moreover, the conformational equilibrium between these redox forms reveals an unexplored cleft for p38α inhibitor design that we describe in detail.© 2023. The Author(s)
Earnings Management: The Effect of Ex Ante Earnings Expectations
Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
A new upper bound for the cross number of finite Abelian groups
In this paper, building among others on earlier works by U. Krause and C.
Zahlten (dealing with the case of cyclic groups), we obtain a new upper bound
for the little cross number valid in the general case of arbitrary finite
Abelian groups. Given a finite Abelian group, this upper bound appears to
depend only on the rank and on the number of distinct prime divisors of the
exponent. The main theorem of this paper allows us, among other consequences,
to prove that a classical conjecture concerning the cross and little cross
numbers of finite Abelian groups holds asymptotically in at least two different
directions.Comment: 21 pages, to appear in Israel Journal of Mathematic
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The ability of analysts’ recommendations to predict optimistic and pessimistic forecasts
Previous researches show that buy (growth) companies conduct income increasing earnings management in order to meet forecasts and generate positive forecast Errors (FEs). This behavior however, is not inherent in sell (non-growth) companies. Using the aforementioned background, this research hypothesizes that since sell companies are pressured to avoid income increasing earnings management, they are capable, and in fact more inclined, to pursue income decreasing Forecast Management (FM) with the purpose of generating positive FEs. Using a sample of 6553 firm-years of companies that are listed in the NYSE between the years 2005–2010, the study determines that sell companies conduct income decreasing FM to generate positive FEs. However, the frequency of positive FEs of sell companies does not exceed that of buy companies. Using the efficiency perspective, the study suggests that even though buy and sell companies have immense motivation in avoiding negative FEs, they exploit different but efficient strategies, respectively, in order to meet forecasts. Furthermore, the findings illuminated the complexities behind informative and opportunistic forecasts that falls under the efficiency
versus opportunistic theories in literature
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