Nonrepetitive Colourings of Planar Graphs with O(log⁡n)O(\log n) Colours

A vertex colouring of a graph is \emph{nonrepetitive} if there is no path for which the first half of the path is assigned the same sequence of colours as the second half. The \emph{nonrepetitive chromatic number} of a graph $G$ is the minimum integer $k$ such that $G$ has a nonrepetitive $k$-colouring. Whether planar graphs have bounded nonrepetitive chromatic number is one of the most important open problems in the field. Despite this, the best known upper bound is $O(\sqrt{n})$ for $n$-vertex planar graphs. We prove a $O(\log n)$ upper bound

The beginning of senior career in team sport is affected by relative age effect

Many previous studies in national team sports did not report evidence about relative age effect (RAE) in senior categories. This study aimed for the first time to determine if the RAE may specifically affect the early, but not the late, phase of senior career in elite team sports. A total of 3,319 birthdates (basketball: n = 642; rugby: n = 572; soccer: n = 1318; volleyball: n = 337; water polo: n = 450) of elite senior players were analyzed. Senior players with an age lower or equal to the 25 percentile of age were considered as early phase players while the others as late phase players. Separate Poisson regression models were applied to investigate the RAE in each sport (overall, and for early phase and late phase subgroups). Considering the overall sample, players born close to the beginning of the year were 1.57, 1.34, 2.69, 1.48, and 1.45 times more likely to reach first and second Italian division of basketball, rugby, soccer, volleyball, and water polo respectively, than those born in the last part of the year. RAE was present in all early phase subgroups. Differently, in the late phase subgroups the RAE was present only in soccer. Data highlighted a bias in the selection of senior teams, which may limit the chance to identify talented players born late in the second part of the year. Italian sport federations should promote the talent development of relatively younger players by equally promoting the joining of young players to senior teams

Post-mortem diagnosis of intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare (<1%), typically aggressive extranodal variant of mature non-Hodgkin B-cell lymphoma. IVLBCL is characterized by malignant lymphoid cells lodged within blood vessels, particularly capillary channels. Herein, we present a case of a 50-year-old man with a history of myeloradiculitis (∼1 year) and paraparesis requiring hospitalization. During the course of his hospital stay, computed tomography (CT), magnetic resonance imaging, CT-positron emission tomography, and biopsy failed to establish a diagnosis. The patient died 2 months later from bilateral pneumonia. Postmortem examination was undertaken to determine the cause of death. Histologic sections of the patient’s brain, heart, lung, and liver showed aggregates of highly atypical cells bearing enlarged, pleomorphic, and hyperchromatic nuclei. Strong intravascular positivity for CD45 and CD20 markers indicated the cells were of B-cell origin, supporting a diagnosis of IVLBCL

First-in-man craniectomy and asportation of solitary cerebellar metastasis in COVID-19 patient: A case report

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has an impact on the delivery of neurosurgical care, and it is changing the perioperative practice worldwide. We present the first case in the literature of craniectomy procedure and asportation of a solitary cerebellar metastasis of the oesophagus squamous carcinoma in a 77 years old woman COVID-19 positive. In these particular circumstances, we show that adequate healthcare resources and risk assessments are essential in the management of COVID-19 patients referred to emergency surgery. Presentation of case: The case here presented was treated in 2019 for squamous carcinoma of the oesophagus. In April 2020, she presented a deterioration of her clinical picture consisting of dysphagia, abdominal pain, hyposthenia and ataxia. A Head CT scan was performed, which showed the presence of a solitary cerebellar metastasis. Her associated SARS-CoV-2 positivity status represented the principal clinical concern throughout her hospitalisation. Discussion: The patient underwent a suboccipital craniectomy procedure with metastasis asportation. She tested positive for SARS-CoV-2 in the pre- and post-operative phases, but she was not admitted to the intensive care unit because she did not present any respiratory complications. Her vital parameters and inflammation indexes fell within the reference ranges, and she was kept in isolation for 16 days in our neurosurgical unit following strict COVID-19 measures. She was asymptomatic and not treated for any of the specific and non-specific symptoms of COVID-19. Conclusion: This is the first case reported of solitary cerebellar metastasis of oesophagus carcinoma operated on a COVID-19 positive patient. It shows that asymptomatic COVID-19 positive patients can undergo major emergency surgeries without the risk of infecting the operating team if adequate Personal Protection Equipment (PPE) is used. The patient remained asymptomatic and did not develop the disease's active phase despite undergoing a stressful event such as a major emergency neurosurgical procedure. In the current crisis, a prophylactic COVID-19 screening test can identify asymptomatic patients undergoing major emergency surgery and adequate resource planning and Personal Protective Equipment (PPE) for healthcare workers can minimise the effect of the COVID-19 pandemic

SARS-CoV-2 and COVID-19. Facing the pandemic together as citizens and cardiovascular practitioners

Despite their highbrow name, coronarvirus have proved eminently disruptive in recent years. Since the epidemic of severe respiratory distress syndrome (SARS) due to the SARS-related coronavirus (SARS-CoV) infection and the Middle East respiratory syndrome (MER S) due to the MER S-related coronavirus (MER S-CoV), several experts could expect the advent of additional epidemics due to coronaviruses. Yet, the ongoing pandemic of coronavirus-associated disease 2019 (COVID -2019) due to the infection from SARS-CoV-2 (also known as 2019-nCoV) has wreaked havoc worldwide (Figure 1). As Italian citizens and cardiovascular practitioners, we are now facing this storm, with a mix of incredulity, fear, boldness, and sense of duty

A case report of osteochondroma of the frontotemporosphenoidal suture.

Osteochondroma, also known as osteocartilaginous exostosis, is the most frequent benign bone tumour of the skeletal system. Despite its preference for long bones (tibia and femur), osteochondroma may occur in some short bones developing endochondral ossification. Seventy-five percent of the patients present only with a single lesion, whereas 25% have multiple lesions; this last clinical condition, defined as osteochondromatosis (disorder of autosomal dominant inheritance) shows a high risk of malignant transformation (about 11%). In the craniofacial area this tumour is very rare. The sites of predilection are the coronoid process and mandibular condyle, even though osteochondromas arising from the base of the skull, maxillary sinus and zygomatic arch have been previously described. However, an osteochondroma originating from the frontotemporosphenoidal suture has not been reported before in the literature. We present a unique case of osteochondroma of the frontotemporosphenoidal suture. Moreover, the relevant international literature has been reviewed and all diagnostic and surgical matters have been discussed

Extracting Nuclear Transparency from p-A Cross sections

We study nuclear structure effects on the transparency in high transverse momentum $(p,2p)$ and $(e,e'p)$ reactions. We show that in the DWIA-eikonal approximation, even when correlations are included, one can get a factorized expression for the transparency. This depends only on the average nucleon density $\rho(r)$ and a correlation function. We develop a technique to include correlations in a Monte-Carlo Glauber type calculation. We compare calculations of $T$ using the eikonal formalism and a continuous density, with a Monte Carlo method based on discrete nucleons.Comment: 22 pages, 9 postscript figures. LaTeX with epsf styl

Economic evaluation of sublingual immunotherapy vs. symptomatic treatment in allergic asthma

The worldwide increased prevalence of allergic diseases, and especially of respiratory allergy, is paralleled by increased health costs. This requires consideration of the cost to efficacy ratio of the available treatment to identify the optimal choice