From humanitas to amicitia

The article aims to investigate Cicero’s epistle Fam. 15.21 (46 BC), which is addressed to Trebonius, a former colleague of him and now a lieutenant of Caesar, and deals with the oratory of Calvus, an Atticist (and Catullus’ best friend), to whom Cicero had given praise and rhetorical advice in a previous letter. Cicero shows affection to Trebonius, and care to Calvus, although they weren’t quite friends of him and belonged to different parties, both in politics and oratory. An examination of the text from the point of view of form and content shows here a double example of humanitas both as benevolence (philantrophia) and as an intellectual and didactic approach (paideia). It seems the prelude to a true friendship (which is also the theme of a future dialogue of Cicero), maybe with further effects (Trebonius will participate in the conspiracy against Caesar). Moreover, several allusions and some playful situations related to the letter (such as the gift of a book containing Cicero’s jokes) recalls Catullus’ poems to his friends (above all to Calvus), confirming the idea of ​​a literary contact between the poeta novus and the orator. The result is an intertwining of personal and cultural relationships between personalities who are traditionally believed to be on opposite sides, but are closer than one might think in Cicero’s correspondence.

Segmenting the Universe into dynamically coherent basins

ABSTRACT This paper explores in depth a watershed concept to partition the Universe, introduced in a previous Letter and applied to the Cosmicflows-3 observational data set. We present a series of tests conducted with cosmological dark matter simulations. In particular, we are interested in quantifying the evolution with redshift of large-scale structures when defined as segmented basins of attraction. This new dynamical definition in the field of measuring standard rulers demonstrates robustness since all basins show a density contrast δ above 1 (mean Universe density) independently of the simulation spatial resolution or the redshift. Another major finding is that density profiles of the basins show universality in slope. Consequently, there is a unique definition of what is a gravitational watershed at a large scale, which can be further used as a probe for cosmology studies.

An Evolutionary Scheme for Secondary Virtual Networks Mapping onto Cognitive Radio Substrate

The Fifth Generation (5G) of wireless communication is envisioned to comprise heterogeneous applications, different radio access technologies (RATs), and a large demand for mobile traffic. In this respect, Wireless Virtualization (WV) and Cognitive Radio (CR) are put forward as 5G enablers for providing additional spectrum resources through dynamic spectrum access (DSA) techniques, besides dealing with heterogeneity with no hardware modification. By empowering the synergy between CR and WV, we visualize an environment denoted as Cognitive Radio Virtual Networks Environment (CRVNE) that encompasses VWNs with different access priorities, called Primary Virtual Networks (PVNs) and Secondary Virtual Networks (SVNs) that may be deployed in an overlay manner. In this scenario, the SVNs users (SUs) access the resources opportunistically, which naturally raises challenges towards the SVN mapping. In this paper, we revisit our previous letter that models the interactions between PUs and SUs in a CRVNE and analyzes a proposed formulation for collision probability during the SVN mapping process. The current work is pioneer as it presents a comprehensive approach to the SVNs mapping problem; models, validates, and analyzes additional performance metrics such as SU blocking and SU dropping probabilities and joint utilization; formulates the SVNs mapping as a multiobjective problem; and proposes an evolutionary scheme based on Genetic Algorithms (GAs) to solve it. The results show that the proposed scheme outperforms the alternative method in terms of collision, SU dropping, SU blocking probabilities, and joint utilization under different primary and secondary loads.

Letter to Margaret Torrie

Letter from Winnicott to Margaret Torrie adding to the previous letter, quoting the analyst Thomas Main, and remembering Winnicott’s early career.

Letter to The Observer

Winnicott’s letter to The Observer in response to some readers who had understood his previous letter to The Observer to be implying that Winnicott appeared to blame parents for their child’s autism.

Paper retractions do not induce citation mutations

Dear Christian Specht,Thank you very much for your detailed response in The Scientist to our previous letter regarding citation mutations. You clarified several issues that were raised in your original study, ...

Construing Collective Concerns

The following article has been retracted by the Editor and publishers of Psychological Science at the request of the lead author, Lawrence J. Sanna: Sanna, L. J., Chang, E. C., Parks, C. D., & Kennedy, L. A. (2009). Construing collective concerns: Increasing cooperation by broadening construals in social dilemmas. Psychological Science, 20, 1319–1321. doi:10.1111/j.1467-9280.2009.02458.x In a letter to the Editor (Eric Eich), Dr. Sanna wrote: The data reported in this article are invalid and should not be considered part of the scientific literature. The responsibility for this problem rests solely with the first author, Lawrence J. Sanna. Coauthors Edward C. Chang, Craig D. Parks, and Lindsay A. Kennedy are in no way responsible for this problem. In response, the Editor noted that Psychological Science follows the retraction guidelines developed by the Committee on Publication Ethics (COPE). Dr. Sanna was urged to follow these guidelines carefully in drafting a retraction notice, particularly with respect to stating the reasons for the retraction, to distinguish misconduct from honest error. To assist Dr. Sanna with this task, the Editor provided Dr. Sanna with a copy of the COPE guidelines ( http://publicationethics.org/resources/guidelines ) and a link to a retraction notice that was published in Psychological Science last year. This notice was considered a "model" by Retraction Watch, and Dr. Sanna was advised that, in keeping with this notice, he "must specify clearly the reasons for the retraction in such language that all of your coauthors agree to it." While awaiting Dr. Sanna's reply, the Editor sought to contact Dr. Sanna's three coauthors. Although one coauthor was aware of Dr. Sanna's request to retract the 2009 Psychological Science article, the other two were not. All of the coauthors have agreed to retraction of the article, and each has received a copy of this notice. Dr. Sanna replied by noting with regret that "research errors" have made it necessary for him to request retraction. The letter concluded with the following: "At the direction of legal counsel, I am unable to say anything further than that contained in my previous letter at this time." Because it is unclear when, if ever, details on these research errors will be forthcoming, the Editor owes it to the journal's readership to retract the article now, even though this notice does not reflect COPE guidelines or journal policy.