51,219 research outputs found
Correction: Differences between experimental and placebo arms in manual therapy trials: a methodological review (BMC Medical Research Methodology, (2022), 22, 1, (219), 10.1186/s12874-022-01704-8)
No full textFollowing publication of the original article [1], the authors reported an error in the presentation of author names. The given name and family name were swapped. The correct author names are as follows: Giandomenico D’Alessandro, Nuria Ruffini, Alessandro Aquino, Matteo Galli, Mattia Innocenti, Marco Tramontano, Francesco Cerritelli. The author group has been updated above and the original article [1] has been corrected
The diameter of cortical axons depends both on the area of origin and target
No full textIn primates, different cortical areas send axons of different diameters into comparable tracts, notably the corpus callosum (Tomasi S, Caminiti R, Innocenti GM. 2012. Areal differences in diameter and length of corticofugal projections. Cereb Cortex. 22:1463-1472). We now explored if an area also sends axons of different diameters to different targets. We find that the parietal area PEc sends thicker axons to area 4 and 6, and thinner ones to the cingulate region (area 24). Areas 4 and 9, each sends axons of different diameters to the nucleus caudatus, to different levels of the internal capsule, and to the thalamus. The internal capsule receives the thickest axon, followed by thalamus and nucleus caudatus. The 2 areas (4 and 9) differ in the diameter and length of axons to corresponding targets. We calculated how diameter determines conduction velocity of the axons and together with pathway length determines transmission delays between different brain sites. We propose that projections from and within the cerebral cortex consist of a complex system of lines of communication with different geometrical and time computing properties. © The Author 2013
Promises in Group Decision Making
No full textWe assess in the laboratory the impact of promises on group decision-making. The gift-exchange game provides the testing ground for our experiment. When played between groups, inter-group cooperation and reciprocity represent a condition for efficiency in overall decision making. We find that promises have a significant positive effect on aggregate profits. We interpret these findings as if promises act as a trigger of social conformity, according to which groups adopt socially more desirable behavior even without face-to-face communication or discussion
Design of Phasing Trajectories From a Low Lunar Orbit To a Near Rectilinear Halo Orbit
No full textThe paper presents three different approaches to the design of a phasing trajectory in a cislunar
environment, where the third body perturbation is considered non-negligible. The working
framework is the one proposed by the ESA’s Heracles mission in witch the passive target
spacecraft -LOP-G- is orbiting on a Near Rectilinear Halo Orbit and the Lunar Ascent Element
must reach that orbit from a Low Lunar Parking Orbit to start the rendezvous procedure.
In this scenario the authors propose three different ways to design such phasing manoeuvre
under the Circular Restricted Three Body Problem hypotheses: Lambert/Differential correction,
Hohmann/Differential correction and Optimization. The three approaches are compared
in therms ofV consumption, accuracy and time of flight. Finally, a selected solution is also
validated under the Restricted Elliptic Three Body Problem Hypotheses
Thrust Expenditure Feasibility Analysis for Rendezvous Operations in Cis-Lunar Space
No full textIn recent years, Moon exploration has become a primary objective within most space agencies worldwide. The Lunar Space Gateway program ARTEMIS (or LOP-G) is an example of mission proposal for technology feasibility in terms of autonomous (and later manned) operations of a space station orbiting the L2 Earth – Moon Lagrangian point. Rendezvous and docking (berthing) are tasks that are envisioned to be performed fully autonomously. The focus of the paper falls in this category, whereby an active module called Lunar Ascender Element (LAE), returning from the lunar surface, shall be able to operate an automatic rendezvous mission with the LOP-G station. The paper concentrates, in particular, with the feasibility analysis needed to assess the engines’ thrust capabilities to provide appropriate propulsion for open loop and closed loop control during rendezvous. The capability of providing the desired amount of thrust is not only linked to the actual guidance commands, but also to the nature of the motors. The rendezvous maneuver sequence, dynamics and hold points are first defined, and the thrust distribution and configuration detailed for the specific mission. The guidance logics are described, and the implementation of a passively safe trajectory outlined. Based on the dynamic model of the system, and the assumed actuator model, the main causes of unfeasibility are listed. The paper continues by analyzing the sensitivity of the thrust profile at each motor with respect to the control allocation algorithm, the duration of the maneuver, the duration of each impulse (assuming a two-impulse maneuver), and the location of the berthing port within a selected near rectilinear halo orbit around the Moon. The tests take into account how the parameters influence the Delta V required to perform the mission. The authors wish to remark that this analysis is critical to the design of rendezvous and berthing (docking) operations, since feasibility is necessary for the success of the mission, and it provides a structured computation of a realistic parameter space in the relative motion in the presence of a third body perturbation
Major scalp defect reconstruction with free flap: analysis of the results
No full textIntroduction: The purposes of this study were to report 10-years experiences in microsurgical reconstruction of major scalp defects, comparing outcomes, evaluating complications. Materials and methods: From November to July 2015, 10 consecutive patients underwent microsurgical procedures for severe scalp defects. Results: The average age was 55,1 years ranging from 6 to 87 years. The mean follow-up was 16.7 months ranging from 12 to 24 months. The size of the lesions ranged from 9x10 to 16x20cm. The average hospital stay was 20 days ranging from 8 to 43 days. Mean operative times was 5.3 h ranging from 5 to 6.45 h. Free flaps included 8 Latissimus Dorsi flaps (LD) and 2 anterolateral thigh flaps (ALT). The superficial temporal vessels were used as recipient vessels in 9 cases while the superior Thyroid artery was used in remain-ing case. Discussion: For large or complex lesions, the use of free flaps is mandatory. Nowadays LD and ALT flaps are among the most common reconstructive choices for scalp defects reconstructions. Older age does not contraindicate the operation procedure nevertheless in younger patients the size of vessels is proportionately larger and pristine. Conclusion: Microvascular free tissue transfer is the mainstay of scalp defects coverage. In our series early complications are less common and concerning than late complications and in fact reopera-tions are mainly required to manage these latter. Advanced age should be not consider a contraindication for free flap surgery and the procedure can be considered safe and reliable in both old and young population. (www.actabiomedica.it)
Recurrent digital fibromatosis of childhood
No full textThe Author report on a case of recurrent digital fibromatosis in a chil
Do collembola affect the competitive relationships among soil-borne plant pathogenic fungi?
No full textThe feeding preference of the collembolan Protaphorura armata in the presence of Fusarium culmorum and Gaeumannomyces graminis var. tritici, two soil-borne fungi pathogenic for winter cereals, was studied in a simplified experimental system including wheat seedlings. Analysis of gut content of all animals from microcosms containing inoculum of both fungi showed that F. culmorum was clearly preferred but that G. graminis var. tritici was also fed. At microscopic examination the majority of F. culmorum conidia present in the gut lacked cytoplasmic content, and only few conidial cells were intact. The feeding preference of P. armata favoured G. graminis var. tritici over F. culmorum in the competition for infection sites on wheat plants; in fact, the former resulted the prevalent cause of plant disease. The viability of fungal propagules after passage through the gut of P. armata was also studied. No colonies of G. graminis var. tritici and only a few colonies of F. culmorum developed from faecal pellets set on agar medium. Fungal propagules dispersed by springtails were not sufficient to induce disease, as demonstrated by introducing animals, previously fed on fungal cultures separately, into microcosms containing a sterile substrate where wheat kernels were seeded. & 2004 Elsevier GmbH. All rights reserved
External Quilting: New Technique to Avoid Haematoma in Gynaecomastia Surgery
No full textWe read with great interest the article titled: “External Quilting: New Technique to Avoid Haematoma in Gynaecomastia Surgery” by Murugesan et al. The authors presented their personal technique adopting external quilting suture in gynaecomastia correction, with the aim of preventing haematoma and avoiding drain placement. We completely agree with the authors that seroma, when liposuction is included in gynaecomastia, and haematoma remain the most common early complications which may necessitate a return to the theatre [1, 2]. According to the authors, we don’t retain the use of drains which is mandatory for this type of surgery, unless a valid haemostasis is performed directly. The use of drains should be suggested only in patients with large amounts of breast gland removal or in the presence of a coagulation disorder, although the final choice for their insertions should be made during the operation. Nevertheless, we have some elements to discuss. Although the effort to minimize the length of the surgical access is very important in aesthetic surgery, a small incision about 1.5–2 cm in length in the inferior part of the areola allows a direct view of the surgical field during glandular resection, ensures valid control of haemostasis and permits internal quilting, leaving inconspicuous scarring. Internal quilting is not visible and therefore allows more satisfaction with the result in the immediate post-op avoiding any patients’ displeasure due to track of the external marks. Internal quilting has no need to be removed, and maintaining, for a long time a firm connection of the adipocutaneous thoracic flap to the pectoralis fascia, they could guarantee a better recontouring of the extra skin onto the new pectoralis profile, especially in the most severe form of gynaecomastia. Moreover, since seroma represents a popular complication, internal quilting, avoiding dead space permanently, can reduce the incidence of this common disorder especially in overweight patients. Although extra-areolar scar could be particularly visible, especially in the presence of pathological scarring, since a stab incision was performed in the anterior axillary line, a temporary drain should be considered; the drain’s vacuum helps to avoid dead space as well as a compressive jersey medical dressing [3,4,5]. Moreover, although the incidence of breast cancer in males is very low, we retain that histological investigation is always recommendable even in the absence of clinical suspicion especially in young patients (Fig. 1)
DESIGN OF THE PHASING TRAJECTORY FROM A LOW LUNAR ORBIT TO NEAR RECTILINEAR HALO ORBIT
No full textThe paper describes the preliminary design of a phasing trajectory in a cislunar environment, where the third body perturbation is considered non-negligible. The working framework is the one proposed by the ESA’s Heracles mission in which a passive target station is in a Near Rectilinear Halo Orbit and an active vehicle must reach that orbit to start a rendezvous procedure. In this scenario the authors examine three different ways to design such phasing maneuver under the circular restricted three-body problem hypotheses: Lambert/differential correction, Hohmann/differential correction and optimization. The three approaches are compared in terms of ∆V consumption, accuracy and time of flight. The selected solution is also validated under the more accurate restricted elliptic three-body problem hypothesis
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