Geografie di oggi. Metodi e strategie tra ricerca e didattica

Questo volume è l’esito del confronto e delle riflessioni sviluppate durante il II Workshop “AIIG Giovani” organizzato a Roma nell’aprile del 2013. Nasce da un desiderio, quello di presentare l’importanza della combinazione tra metodi d’indagine tradizionali e nuovi per costruire sapere geografico, e da una passione, sostenuta dall’intreccio di relazioni umane che si evolvono nel tempo. Per chiarire quale possa essere il contributo della geografia alla comprensione del mondo contemporaneo, sempre più complesso, gli autori presentano le principali metodologie geografiche in quattro sezioni: “Territori della tecnologia”, “Identità, spazi, luoghi”, “Nodi della rete” e “Approcci sperimentali nella scuola che cambia”. Emerge dal lavoro un quadro multifocale che rispecchia la poliedricità e la trasversalità della geografia contemporanea, ancorato al comune bisogno di sviluppare strumenti interpretativi e d’azione. Ci si muove nell’ambito di una geografia critica e della complessità in grado di fornire ai cittadini globali differenti strumenti di interpretazione e comprensione del mondo, nuove metafore a partire dalle quali costruire e sperimentare forme alternative di cittadinanza consapevole ed attiva. Qui la geografia ritrova lo slancio di una disciplina fertile capace non solo di descrivere la Terra, ma anche di immaginare e creare nuovi mondi possibili. L’approdo naturale di questo percorso è la realtà scolastica dove è possibile sperimentare nuove forme di sapere e azione per rispondere alla sfida educativa contemporanea

Operative Management of Symptomatic, Metachronous Carotid Body Tumors Involving the Skull Base and Its Neurological Sequelae

A 44-year-old morbidly obese woman with a history of right carotid body tumor (CBT) resection presented with a symptomatic, nonfunctional, left Shamblin-III CBT. Abutment of the skull base precluded distal internal carotid artery control for arterial reconstruction, favoring parent vessel sacrifice after an asymptomatic provocative test. She underwent CBT resection with anticipated sacrifice of cranial nerves X and XII and the common carotid artery and its branches, developing baroreceptor failure syndrome and sequelae of cranial nerve sacrifice. When facing a symptomatic, metachronous CBT abutting the skull base, upfront operative intervention with adjuvant radiation for residual tumor optimizes curative resection

The Expanding Universe of Prion Diseases

Prions cause fatal and transmissible neurodegenerative disease. These etiological infectious agents are formed in greater part from a misfolded cell-surface protein called PrP(C). Several mammalian species are affected by the diseases, and in the case of “mad cow disease” (BSE) the agent has a tropism for humans, with negative consequences for agribusiness and public health. Unfortunately, the known universe of prion diseases is expanding. At least four novel prion diseases—including human diseases variant Creutzfeldt-Jakob disease (vCJD) and sporadic fatal insomnia (sFI), bovine amyloidotic spongiform encephalopathy (BASE), and Nor98 of sheep—have been identified in the last ten years, and chronic wasting disease (CWD) of North American deer (Odocoileus Specis) and Rocky Mountain elk (Cervus elaphus nelsoni) is undergoing a dramatic spread across North America. While amplification (BSE) and dissemination (CWD, commercial sourcing of cervids from the wild and movement of farmed elk) can be attributed to human activity, the origins of emergent prion diseases cannot always be laid at the door of humankind. Instead, the continued appearance of new outbreaks in the form of “sporadic” disease may be an inevitable outcome in a situation where the replicating pathogen is host-encoded

Operational approach to open dynamics and quantifying initial correlations

A central aim of physics is to describe the dynamics of physical systems. Schrodinger's equation does this for isolated quantum systems. Describing the time evolution of a quantum system that interacts with its environment, in its most general form, has proved to be difficult because the dynamics is dependent on the state of the environment and the correlations with it. For discrete processes, such as quantum gates or chemical reactions, quantum process tomography provides the complete description of the dynamics, provided that the initial states of the system and the environment are independent of each other. However, many physical systems are correlated with the environment at the beginning of the experiment. Here, we give a prescription of quantum process tomography that yields the complete description of the dynamics of the system even when the initial correlations are present. Surprisingly, our method also gives quantitative expressions for the initial correlation.Comment: Completely re-written for clarity of presentation. 15 pages and 2 figure

Dienogest alone or dienogest combined with estrogens in the treatment of ovarian endometriomas, that is the question. A retrospective cohort study

Purpose: to compare the effects of Dienogest 2 mg (D) alone or combined with estrogens (D + ethinylestradiol 0.03 mg, D + EE; D + estradiol valerate 1-3 mg, D + EV) in terms of symptoms and endometriotic lesions variations. Methods: This retrospective study included symptomatic patients in reproductive age with ultrasound diagnosis of ovarian endometriomas. Medical therapy for at least 12 months with D, D + EE or D + EV was required. Women were evaluated at baseline visit (V1) and after 6 (V2) and 12 months (V3) of therapy. Results: 297 patients were enrolled (156 in the D group, 58 in the D + EE group, 83 in the D + EV group). Medical treatment leaded to a significant reduction in size of endometriomas after 12 months, with no differences between the three groups. When comparing D and D + EE/D + EV groups, a significant decrease of dysmenorrhea was detected in the D group than in D + EE/D + EV group. Conversely, the reduction of dysuria was more significative in the D + EE/D + EV groups rather than in the D group. Regarding tolerability, treatment associated side effects were reported by 16.2% patients. The most frequent one was uterine bleeding/spotting, significantly higher in the D + EV group. Conclusion: Dienogest alone or associated with estrogens (EE/EV) seems to be equally effective in reducing endometriotic lesions mean diameter. The reduction of dysmenorrhea was more significative when D was administered alone, while dysuria seems to improve more when D is associated with estrogens

Application of deep learning model in the sonographic diagnosis of uterine adenomyosis

Background: This study aims to evaluate the diagnostic performance of Deep Learning (DL) machine for the detection of adenomyosis on uterine ultrasonographic images and compare it to intermediate ultrasound skilled trainees. Methods: Prospective observational study were conducted between 1 and 30 April 2022. Transvaginal ultrasound (TVUS) diagnosis of adenomyosis was investigated by an experienced sonographer on 100 fertile-age patients. Videoclips of the uterine corpus were recorded and sequential ultrasound images were extracted. Intermediate ultrasound-skilled trainees and DL machine were asked to make a diagnosis reviewing uterine images. We evaluated and compared the accuracy, sensitivity, positive predictive value, F1-score, specificity and negative predictive value of the DL model and the trainees for adenomyosis diagnosis. Results: Accuracy of DL and intermediate ultrasound-skilled trainees for the diagnosis of adenomyosis were 0.51 (95% CI, 0.48–0.54) and 0.70 (95% CI, 0.60–0.79), respectively. Sensitivity, specificity and F1-score of DL were 0.43 (95% CI, 0.38–0.48), 0.82 (95% CI, 0.79–0.85) and 0.46 (0.42–0.50), respectively, whereas intermediate ultrasound-skilled trainees had sensitivity of 0.72 (95% CI, 0.52–0.86), specificity of 0.69 (95% CI, 0.58–0.79) and F1-score of 0.55 (95% CI, 0.43–0.66). Conclusions: In this preliminary study DL model showed a lower accuracy but a higher specificity in diagnosing adenomyosis on ultrasonographic images compared to intermediate-skilled trainees

Kaleidoscope of irradiated disks: MUSE observations of proplyds in the Orion Nebula Cluster: I. Sample presentation and ionization front sizes

In the Orion Nebula Cluster (ONC), protoplanetary disks exhibit ionized gas clouds in the form of a striking teardrop shape as massive stars irradiate the disk material. We present the first spatially and spectrally resolved observations of 12 such objects, known as proplyds, using integral field spectroscopy observations performed with the Multi-Unit Spectroscopic Explorer (MUSE) instrument in Narrow Field Mode (NFM) on the Very Large Telescope (VLT). We present the morphology of the proplyds in seven emission lines and measure the radius of the ionization front (I-front) of the targets in four tracers, covering transitions of different ionization states for the same element. We also derive stellar masses for the targets. The measurements follow a consistent trend of increasing I-front radius for a decreasing strength of the far-UV radiation as expected from photoevaporation models. By analyzing the ratios of the I-front radii as measured in the emission lines of Hα, [O I] 6300 A, [O II] 7330 A, and [O III] 5007 A, we observe the ionization stratification, that is, the most ionized part of the flow being the furthest from the disk (and closest to the UV source). The ratios of ionization front radii scale in the same way for all proplyds in our sample regardless of the incident radiation. We show that the stratification can help constrain the densities near the I-front by using a 1D photoionization model. We derive the upper limits of photoevaporative mass-loss rates (Ṁloss) by assuming ionization equilibrium, and estimate values in the range 1.07–94.5 × 10−7 M⊙ yr−1, with Ṁloss values decreasing towards lower impinging radiation. We do not find a correlation between the mass-loss rate and stellar mass. The highest mass-loss rate is for the giant proplyd 244–440. These values of Ṁloss, combined with recent estimates of the disk mass with ALMA, confirm previous estimates of the short lifetime of these proplyds. This work demonstrates the potential of this MUSE dataset and offers a new set of observables to be used to test current and future models of external photoevaporation

The black hole X-ray transient Swift J1357.2-0933 as seen with Swift and NuSTAR during its 2017 outburst

We report on observations of black hole Swift J1357.2–0933, a member of the modest population of very faint X-ray transients. This source has previously shown intense dips in the optical light curve, a phenomena that has been linked to the existence of a ‘unique toroidal structure’ in the inner region of the disc, seen at a high inclination. Our observations, carried out by the Neil Gehrels Swift and NuSTAR X-ray observatories, do not show the presence of intense dips in the optical light curves. We find that the X-ray light curves do not show any features that would straightforwardly support an edge-on configuration or high inclination configuration of the orbit. This is similar to what was seen in the X-ray observations of the source during its 2011 outburst. Moreover, the broad-band spectra were well described with an absorbed power-law model without any signatures of cut-off at energies above 10 keV, or any reflection from the disc or the putative torus. Thus, the X-ray data do not support the unique ‘obscuring torus’ scenario proposed for J1357. We also performed a multiwavelength study using the data of X-ray telescope and Ultraviolet/Optical Telescope aboard Swift, taken during the ∼4.5 months duration of the 2017 outburst. This is consistent with what was previously inferred for this source. We found a correlation between the simultaneous X-ray and ultraviolet/optical data and our study suggests that most of the reprocessed flux must be coming out in the ultraviolet.Publisher PDFPeer reviewe

Dissipative and Non-dissipative Single-Qubit Channels: Dynamics and Geometry

Single-qubit channels are studied under two broad classes: amplitude damping channels and generalized depolarizing channels. A canonical derivation of the Kraus representation of the former, via the Choi isomorphism is presented for the general case of a system's interaction with a squeezed thermal bath. This isomorphism is also used to characterize the difference in the geometry and rank of these channel classes. Under the isomorphism, the degree of decoherence is quantified according to the mixedness or separability of the Choi matrix. Whereas the latter channels form a 3-simplex, the former channels do not form a convex set as seen from an ab initio perspective. Further, where the rank of generalized depolarizing channels can be any positive integer upto 4, that of amplitude damping ones is either 2 or 4. Various channel performance parameters are used to bring out the different influences of temperature and squeezing in dissipative channels. In particular, a noise range is identified where the distinguishability of states improves inspite of increasing decoherence due to environmental squeezing.Comment: 12 pages, 4 figure