Resummed propagators in multi-component cosmic fluids with the eikonal approximation

We introduce the eikonal approximation to study the effect of the large-scale motion of cosmic fluids on their small-scale evolution. This approach consists in collecting the impact of the long-wavelength displacement field into a single or finite number of random variables, whose statistical properties can be computed from the initial conditions. For a single dark matter fluid, we show that we can recover the nonlinear propagators of renormalized perturbation theory. These are obtained with no need to assume that the displacement field follows the linear theory. Then we extend the eikonal approximation to many fluids. In particular, we study the case of two non-relativistic components and we derive their resummed propagators in the presence of isodensity modes. Unlike the adiabatic case, where only the phase of small-scale modes is affected by the large-scale advection field, the isodensity modes change also the amplitude on small scales. We explicitly solve the case of cold dark matter-baryon mixing and find that the isodensity modes induce only very small corrections to the resummed propagators.Comment: 18 pages, 9 figures, matches published version as PR

Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant disease with rapid fatal prognosis. The onset is generally characterized by sudden bilateral latero-cervical lymphadenopathy. The Authors report patient of 58-year-old who referred for evaluation of rapidly aggravating bilateral latero-cervical lymphadenopathy. The US highlighted the presence of a hypoechoic nodular lesion characterized by peri and intra-nodular vascularization. Multilayer CT showed diffused involvement of mediastinal and bilateral latero-cervical lymph nodes, with no evidence of primary pulmonary neoplasia or elsewhere. The patient underwent total thyroidectomy. The peri-isthmic tissue was removed due to the presence of a small roundish formation, that was due to lymph node metastasis at histological examination. Histological diagnosis: PSCCT. The immunohistochemical panel of the thyroid lesion was indispensable for the differential diagnosis between PSCCT, medullary carcinoma, anaplastic carcinoma, and thyroid metastasis of neoplasia with unknown primitiveness. The patient underwent chemotherapeutic treatment with Carboplatin and Paclitaxel with modest improvement of dysphagia symptoms and reduction of 10-15% of the target lesions. The clinical course was characterized by loco-regional progression of the disease with exitus in 10 months after diagnosis. Survival and quality of life after surgical therapy and chemotherapy were like that of patients undergoing only chemotherapy. Due to the extreme rarity of the neoplasia, 60 cases described in Literature, no exclusive guidelines are reported for PSCCT. More extensive case studies are needed to evaluate the effects of total thyroidectomy with intent R0/R1 on improving survival and quality of life of patients with PSCCT

The Ferroelectric-Ferroelastic Debate about Metal Halide Perovskites

Metal halide perovskites (MHPs) are solution-processed materials with exceptional photoconversion efficiencies that have brought a paradigm shift in photovoltaics. The nature of the peculiar optoelectronic properties underlying such astounding performance is still controversial. The existence of ferroelectricity in MHPs and its alleged impact on photovoltaic activity have fueled an intense debate, in which unanimous consensus is still far from being reached. Here we critically review recent experimental and theoretical results with a two-fold objective: we argue that the occurrence of ferroelectric domains is incompatible with the A-site cation dynamics in MHPs and propose an alternative interpretation of the experiments based on the concept of ferroelasticity. We further underline that ferroic behavior in MHPs would not be relevant at room temperature or higher for the physics of photogenerated charge carriers, since it would be overshadowed by competing effects like polaron formation and ion migration

Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile)

The seismostratigraphic and structural analysis of the whole length of the Magellan Strait, from the Atlantic to the Pacific entrance is for first time illustrated on the basis of multichannel seismic (MCS) profiles. The Strait crosses a geologically complex region that includes different morphotectonic provinces, and has been subdivided into three distinct segments, eastern (Atlantic), central, and western (Pacific), being each segment characterized by peculiar sedimentary and tectonic architectures. The MCS profiles shed light on the subsurface of the region in particular on the Quaternary and Tertiary features. In the foreland basin province, the MCS profiles imaged an almost undeformed structural and stratigraphic frame with very thick Cretaceous to Tertiary package. Seismic evidence of deformation of the foreland units occurs in the fold-and-thrust belt province. Along the Cordillera province, the Magallanes-Fagnano transform fault exerts an important morpho-tectonic control that strongly conditions its bathymetric profile. The seismic profiles also highlighted a number of depositional features linked to the up to 150 m thick sedimentary record of the glacial cycles. Whereas the eastern segment (outer foreland province) is devoid of significant glacial-related deposits, the central segment (inner foreland and fold-and thrust belt provinces) shows evidence of repeated advances and retreats of the Magellan glacier. An important moraine ridge complex, probably corresponding to the glacial advance "D"of Clapperton et al., has been seismically imaged in the central segment, as well as an older, large bank of ice distal sediments that have been interpreted as proglacial lake deposits, which show evident signs of repeated glacial erosions. Ice-contact features in the form of frontal moraine complexes made up of dipping foreset strata are present in the fjord-like, western segment of the Strait (Cordillera province), along with their related ice-proximal and ice-distal facies. Eventually, the occurrence of preglacial sediments tectonized by the Magallanes-Fagnano transform fault has been reported in the same segment. This fact, which is supported by small outcrops reported in the updated geologic map, if substantiated by further investigations (i.e. advanced seismic reprocessing, sea bottom samplings), would prove the relatively young age (Late Miocene?) of the Magallanes-Fagnano transform fault

Study of the Fusion-Fission Process in the 35Cl+24Mg^{35}Cl+^{24}Mg Reaction

Fusion-fission and fully energy-damped binary processes of the $^{35}$Cl+$^{24}$Mg reaction were investigated using particle-particle coincidence techniques at a $^{35}$Cl bombarding energy of E$_{lab}$ $\approx$ 8 MeV/nucleon. Inclusive data were also taken in order to determine the partial wave distribution of the fusion process. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with a relatively large multiplicity of secondary light-charged particles emitted by the two primary excited fragments in the exit channel. No evidence is observed for ternary-breakup processes, as expected from the systematics recently established for incident energies below 15 MeV/nucleon and for a large number of reactions. The binary-process results are compared with predictions of statistical-model calculations. The calculations were performed using the Extended Hauser-Feshbach method, based on the available phase space at the scission point of the compound nucleus. This new method uses temperature-dependent level densities and its predictions are in good agreement with the presented experimental data, thus consistent with the fusion-fission origin of the binary fully-damped yields.Comment: 30 pages standard REVTeX file, 10 eps Figures; to be published at the European Physical Journal A - Hadrons and Nucle

Differential ripple propagation along the hippocampal longitudinal axis

Hippocampal ripples are highly synchronous neural events critical for memory consolidation and retrieval. A minority of strong ripples has been shown to be of particular importance in situations of increased memory demands. The propagation dynamics of strong ripples inside the hippocampal formation are, however, still opaque. We analyzed ripple propagation within the hippocampal formation in a large open access dataset comprising 267 Neuropixel recordings in 49 awake, head-fixed mice. Surprisingly, strong ripples (top 10% in ripple strength) propagate differentially depending on their generation point along the hippocampal longitudinal axis. The septal hippocampal pole is able to generate longer ripples that engage more neurons and elicit spiking activity for an extended time even at considerable distances. Accordingly, a substantial portion of the variance in strong ripple duration (R(2) = 0.463) is explained by the ripple generation location on the longitudinal axis. Our results are consistent with a possible distinctive role of the hippocampal septal pole in conditions of high memory demand

Acute pancreatitis secondary to non-functioning pancreatic neuroendocrine tumor: uncommon clinical presentation. Clinical case and review of literature

I tumori neuroendocrini del pancreas (PNET) sono rari, e rappresentano <5% di tutte le neoplasie pancreatiche, suddivisi in PNET funzionanti con secrezione ormonale responsabile di sintomi specifici e PNET non funzionanti (nf-PNET) generalmente di diagnosi tardiva per la comparsa di metastasi o manifestazioni cliniche per effetti compressivi. L’approccio chirurgico è il trattamento di scelta per PNETs funzionanti, non-funzionanti di diametro superiore a 2 cm o sintomatici per disturbi da compressione. Osservazione personale. Donna di 76 anni ricoverata presso la UOC-Università-Chirurgia Ospedale “A. Fiorini” di Terracina per nausea e dolore ai quadranti addominali superiori con irradiazione dorso-lombare, insorti dopo un pasto serale. Dopo gli esami ematochimici e le indagini strumentali, è stata fatta la diagnosi di pancreatite acuta severa. Gli US convenzionali, CCT, CE-MRI ed EUS hanno mostrato una lesione di 2,8 cm di diametro nella giunzione testa-corpo del pancreas. L’esame citologico FNA non ha rilevato la presenza di cellule pancreatiche atipiche. La scintigrafia total body con Octreoscan® ha documentato un’area di ipercaptazione patologica situata in corrispondenza della neoformazione. La paziente è stata sottoposta a spleno-pancreasectomia corpo-coda. L’esame istologico ha dimostrato un nf-PNET di grado intermedio (G2) stenosante il vena lienale e stenosante il dotto di Wirsung, con pancreatite perilesionale. L’immunoistochimica ha mostrato un immunofenotipo positivo per CAM5.2, sinaptofisina (> 95%) e cromogranina (60%), con espressione di somatostatina intratumorale negativa. CONCLUSIONE: Sebbene raramente un nf-PNETS può essere la causa di grave pancreatite acuta non biliare da compressione del sistema duttale pancreatico. Nei casi in cui la PET / CT68Ga non può essere eseguita, la scintigrafia total body con Octreoscan® rimane il metodo più utilizzato per la diagnosi dei PNET e l’identificazione delle eventuali lesioni extra-pancreatiche. La cromogranina e la sinaptofisina sono confermate come marcatori specifici del differenziamento neuroendocrino.BACKGROUND: Pancreatic neuroendocrine tumors (PNETs) are uncommon, representing <5% of all pancreatic neoplasms, divided into functioning PNETs with secreted hormone cause of specific symptoms, and non-functioning PNETs (nf- PNETs) characterized by delayed diagnosis with metastases and clinical manifestations of compressive effects. Surgical approach is recommended for functioning and nf-PNETs >2 cm in diameter. CASE REPORT: A 76-year-old woman was admitted to the UOC-University-Surgery Hospital "A. Fiorini" in Terracina for nausea and pain in the upper abdominal quadrants with dorso-lumbar irradiation, arising after the evening meal. After the haematochemistry tests and the instrumental investigations, the diagnosis of acute, severe halitiasic pancreatitis was made. Conventional US, CCT, CE-MRI and EUS showed a 2.8cm diameter lesion in the head-body junction of the pancreas. FNA-cytological examination did not found the presence of atypical pancreatic cells. Total-body scintigraphy with Octreoscan® documented a pathological hypercaptation area located in correspondence with the neoformation. The patient underwent a body-tail spleno-pancreatectomy. The histological examination showed an intermediate grade (G2) nf-PNET infiltrating the lienal vein and stenosing the Wirsung duct, with perilesional pancreatitis. Immunohistochemistry showed CAM 5.2, Synaptophysin (>95%) and Chromogranin (60%) positive immunophenotype, with negative intratumoral Somatostatin expression. CONCLUSION: Although rarely, nf-PNETS may be the cause of severe non-biliary acute pancreatitis from pancreatic ductal system compression. In cases where PET/CT68Ga cannot be performed, total-body scintigraphy with Octreoscan® remains the most widely used method for the diagnosis of PNETs and the identification of extra-pancreatic lesions. Chromogranin and Synaptophysin are confirmed as specific markers of neuroendocrine differentiation. KEY WORDS: Acute pancreatitis, Chromogranin, Pancreatic neuroendocrine tumor, Synaptophysin, Somatostatin

Feature- versus rule-based generalization in rats, pigeons and humans

Humans can spontaneously create rules that allow them to efficiently generalize what they have learned to novel situations. An enduring question is whether rule-based generalization is uniquely human or whether other animals can also abstract rules and apply them to novel situations. In recent years, there have been a number of high-profile claims that animals such as rats can learn rules. Most of those claims are quite weak because it is possible to demonstrate that simple associative systems (which do not learn rules) can account for the behavior in those tasks. Using a procedure that allows us to clearly distinguish feature-based from rule-based generalization (the Shanks-Darby procedure), we demonstrate that adult humans show rule-based generalization in this task, while generalization in rats and pigeons was based on featural overlap between stimuli. In brief, when learning that a stimulus made of two components ("AB") predicts a different outcome than its elements ("A" and "B"), people spontaneously abstract an opposites rule and apply it to new stimuli (e.g., knowing that "C" and "D" predict one outcome, they will predict that "CD" predicts the opposite outcome). Rats and pigeons show the reverse behavior-they generalize what they have learned, but on the basis of similarity (e.g., "CD" is similar to "C" and "D", so the same outcome is predicted for the compound stimulus as for the components). Genuinely rule-based behavior is observed in humans, but not in rats and pigeons, in the current procedure