In My Mother\u27s Room

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What memory binding functions is the hippocampus responsible for?

The role of the hippocampus in binding information in working memory (WM) is little understood. When complex experiences comprise associations between different pieces of information such as objects and locations (relational binding), the function of the hippocampus is required to hold them in WM (Mitchell et al., 2000; 2006; Piekema, 2006). However, recent evidence suggests that if the to-be-associated information leads to the formation of integrated objects such as coloured shapes (conjunctive binding), the hippocampus is less involved in holding temporary representations of these complex events in WM (Baddeley et al., 2010; Piekema, 2006). We investigated the relational and conjunctive binding hypotheses of the hippocampal functions in a patient with right hippocampal damage. The patient and controls were asked to study visual arrays of stimuli which consisted of shape-colour relations (shape-colour pairs) or shape-colour conjunctions (coloured shapes). After the study array, they were presented with a new screen consisting of one set of shapes (line drawings) and one set of colours. They were asked to reconstruct the bindings by selecting the shapes and their corresponding colours. As compared to healthy controls, the patient was impaired in holding relations of shapes and colours in WM whereas he could retain the conjunctions similarly to controls. These results lend support to the role of the hippocampus in supporting memory for inter-item associations but not memory for conjunctions of features which define objects' identity

Non-extensive entropy from incomplete knowledge of Shannon entropy?

In this paper we give an interpretation of Tsallis' nonextensive statistical mechanics based upon the information-theoretic point of view of Luzzi et al. [cond-mat/0306217; cond-mat/0306247; cond-mat/0307325], suggesting Tsallis' entropy to be not a fundamental concept but rather a derived one, stemming from an incomplete knowledge of the system, not taking properly into account its interaction with the environment. This interpretation seems to avoid some problems occurring with the original interpretation of Tsallis statistics.Comment: v.4. 11 pages. Title changed. Content substantially changed: added discussion of several points raised by various referees and readers; Also reference made to work by Luzzi, Vasconcellos, Galvao Ramos. Physica Scripta, to appea

Fine-Structure Map of the Histidine Transport Genes in \u3cem\u3eSalmonella typhimurium\u3c/em\u3e

Afine-structure genetic map of the histidine transport region of the Salmonella typhimurium chromosome was constructed. Twenty-five deletion mutants were isolated and used for dividing the hisJ and hisP genes into 8 and 13 regions respectively. A total of 308 mutations, spontaneous and mutagen induced, have been placed in these regions by deletion mapping. The histidine transport operon is presumed to be constituted of genes dhuA, hisJ, and hisP, and the regulation of the hosP and hisJ genes by dhuA is discussed. The orientation of this operon relative to purF has been established by three-point crosses as being: purF duhA hisJ hisP

Paraclinoid aneurysms: Outcome analysis and technical remarks of a microsurgical series

Abstract Introduction A critical appraisal of the surgical results of paraclinoid aneurysms is essential in the flow diverters era. This study overviews the data of a three-decade surgical series of paraclinoid aneurysms while focusing on their technical remarks. Methods Overall data of a surgical consecutive series of paraclinoid aneurysms treated between 1993 and 2021 were retrospectively reviewed. Aneurysms were classified according to size and projection. Indications for surgery were different based on the availability of endovascular techniques, especially flow diverter, at the time of treatment. A statistical comparison between ruptured and unruptured aneurysms was accomplished. Results 58 patients were operated upon. Ophthalmic aneurysms were 68%, giant aneurysms 20%, and ruptured aneurysms 45%. Clipping and bypass were executed in 91% and 9% of cases, respectively. An mRS of 0–2 was achieved in 77% of patients, independently by the clinical onset. The mortality rate was 5%. Visual field was improved or unchanged in 71% of elective patients, whereas the incidence of de novo third and sixth cranial nerves deficit was 8% and 5%, respectively. On an average follow-up of 53.3 ± 38 months, a complete and durable aneurysm exclusion was achieved in 91.3% of patients with a single surgery. Conclusions Microneurosurgery is still a valuable treatment option for selected ruptured and unruptured paraclinoid aneurysms. In our experience, it has proven to be definitive and durable, with acceptable morbidity and mortality. Clipping is the treatment of choice in most surgical cases, achieving a good visual outcome in symptomatic patients

Cranio-Orbito-Zygomatic Approach: Core Techniques for Tailoring Target Exposure and Surgical Freedom

The cranio-orbito-zygomatic (COZ) approach is a workhorse of skull base surgery, and each of its steps has a precise effect on target exposure and surgical freedom. The present study overviews the key techniques for execution and tailoring of the COZ approach, focusing on the quantitative effects resulting from removal of the orbitozygomatic (OZ) bar, orbital rim, and zygomatic arch