246 research outputs found
Migdal effect and photon Bremsstrahlung: improving the sensitivity to light dark matter of liquid argon experiments
The search for dark matter weakly interacting massive particles with noble
liquids has probed masses down and below a GeV/c^2. The ultimate limit is
represented by the experimental threshold on the energy transfer to the nuclear
recoil. Currently, the experimental sensitivity has reached a threshold
equivalent to a few ionization electrons. In these conditions, the contribution
of a Bremsstrahlung photon or a so-called Migdal electron due to the sudden
acceleration of a nucleus after a collision might be sizable. In the present
work, we use a Bayesian approach to study how these effects can be exploited in
experiments based on liquid argon detectors. In particular, taking inspiration
from the DarkSide-50 public spectra, we develop a simulated experiment to show
how the Migdal electron and the Bremsstrahlung photon allow to push the
experimental sensitivity down to masses of 0.1 GeV/c^2, extending the search
region for dark matter particles of previous results. For these masses we
estimate the effect of the Earth shielding that, for strongly interacting dark
matter, makes any detector blind. Finally, we show how the sensitivity scales
for higher exposure.Comment: 30 pages, 13 figures, 2 table
Landslide susceptibility analysis exploiting Persistent Scatterers data in the northern coast of Malta
During the last decade a pressing need for more adequate tools to manage the considerable increasing number of hydrogeological emergencies arose among land planning and civil protection authorities. As a consequence, both development and testing of different qualitative and quantitative methods for landslide displacements detection become fundamental in order to provide the best analysis performance in terms of cost-benefit and scientific reliability. Lately quantitative methods to measure deformations of unstable slopes had great advances. In this context, remotely sensed radar techniques, such as PSI (Persistent Scatterers Interferometry), can assist traditional landslide investigations in assessing ground and infrastructure deformations caused by large landslides.
The main purpose of this study is exploiting the results of PSI analysis conducted over the Island of Malta to train a Bayesan model for evaluating active landslide susceptibility.
This approach has been applied in the NW coast of Malta, where outstanding coastal landslides, such as rock spreads and block slides, have been recognized and mapped.
The outcomes of the statistical analysis have been validated through specific field check and GNSS measurements. The results show that the developed susceptibility model predicts an acceptable percentage of landslides and can be considered reliable even if in areas without PSI data
Metronomic Capecitabine Effectively Blocks Leptomeningeal Carcinomatosis From Breast Cancer: A Case Report and Literature Review.
BACKGROUND Meningeal carcinomatosis is a rare complication in breast cancer patients. At present, there are no defined guidelines for its management. The efficacy of systemic treatment seems to depend on its ability to cross the blood-brain-barrier and its interaction with tumor vasculature. Metronomic chemotherapy is a known modality of drug administration able to inhibit tumor angiogenesis. CASE REPORT We present a case of symptomatic leptomeningeal carcinomatosis from breast cancer successfully treated with capecitabine. Based on the hypothesis that angiogenesis contributes to neoplastic meningitis, the patient was treated with a metronomic schedule that provided long-term clinical benefit with a very low toxicity profile. CONCLUSIONS To assess the real impact of metronomic chemotherapy in patients with meninges involvement, a phase II study will be starting soon in our institution. A review of the literature concerning the management of meningeal carcinomatosis is also presented
Effects of fiscal policy in the North and South of Italy
Abstract: This paper contributes to a growing body of work within ‘fiscal policy studies’, investigating for the recent role of fiscal policy on the Italian economy. Using annual data collected on regional basis, this study estimates and compares the (impact and cumulative) fiscal multipliers across the North and the South, the less developed area, of Italy. With recourse to a simultaneous equation model for the two macro-regions of Italy, it estimates the overall impact of the measures of budget consolidation policies in the period 2011-2013. Our analysis reveals that tax rises and spending cuts hit the South harder than the North
Effects of fiscal policy in the North and South of Italy
Abstract: This paper contributes to a growing body of work within ‘fiscal policy studies’, investigating for the recent role of fiscal policy on the Italian economy. Using annual data collected on regional basis, this study estimates and compares the (impact and cumulative) fiscal multipliers across the North and the South, the less developed area, of Italy. With recourse to a simultaneous equation model for the two macro-regions of Italy, it estimates the overall impact of the measures of budget consolidation policies in the period 2011-2013. Our analysis reveals that tax rises and spending cuts hit the South harder than the North
Neoadjuvant treatments in triple-negative breast cancer patients: where we are now and where we are going
Abstract: Triple-negative breast cancer (TNBC) remains the poorest-prognosis breast cancer
(BC) subtype. Gene expression profiling has identified at least six different triple-negative
subtypes with different biology and sensitivity to therapies. The heterogeneous nature of TN
tumors may justify the difficulty in treating this BC subtype. Several targeted agents have been
investigated in clinical trials without demonstrating a clear survival benefit. Therefore, systemic
chemotherapy remains the cornerstone of current clinical practice. Improving the knowledge of
tumor biology is mandatory for patient management. In stages II and III, neoadjuvant systemic
treatment is an effective option of care. The achievement of a pathological complete response
represents an optimal surrogate for survival outcome as well as a test for tumor drug sensitivity.
In this review, we provide a brief description of the main predictive biomarkers for tumor
response to systemic treatment. Moreover, we review the treatment strategies investigated for
TNBCs in neoadjuvant settings focusing on experimental drugs such as immunotherapy and
poly [ADP-ribose] polymerase inhibitors that hold promise in the treatment of this aggressive
disease. Therefore, the management of TNBC represents an urgent, current, unmet need in daily
clinical practice. A key recommendation is to design biology-driven clinical trials wherein TNBC
patients may be treated on the basis of tumor molecular profile
Impact of anaemia on tumor response to neoadjuvant chemotherapy in breast cancer patients .
BACKGROUND - Pathological complete response (pCR) to neoadjuvant systemic therapy (NST) in patients with breast cancer (BC) predicts long-term outcomes.
Anaemia is one of the most common side effects of cytotoxic drugs. Biologically, anaemia induces adaptive responses due to the low intra-tumoral oxygen levels that may be responsible for increase chemotherapy resistance. In literature, data regarding this issue are lacking.
AIM - To evaluate the influence of anaemia throughout treatment course on tumour shrinkage induced by NST. METHODS - Patients - 317 patients diagnosed with stage I-III BC treated with NST and with available blood tests were included. Patients and tumor characteristics and treatments information were collected. We focused on Haemoglobin (Hb) level (at baseline, at the end of NST, drop in Hb throughout treatment and duration of anaemia) and its correlation with pCR rate. Anaemia was defined as a drop of Hb under the local limit of normal in women (12 mg/dl).
Statistical analysis - Categorical variables were analyzed using chi-square test or Fisher's exact test, continuous variables using t test. Univariate and multivariate analyses were fit to determinate the association between anaemia and pCR rate. A p-value < 0.05 was considered statistically significant; hazard ratio was estimated with 95% of confidence limits. RESULTS- No difference in Hb levels was observed stratifying patients according to nuclear grade, tumor stage, cancer subtypes and chemotherapy regimens. Median baseline Hb was 13.3 g/dl while median Hb level at the end of NST was 10 g/dl. 31 patients had pre-treatment anaemia. 60% of patients developed anaemia during NST period. In the subgroup of anaemic patients, who had a decrease in Hb ≥ 2 g/dl from baseline or anaemia longer than two months, a lower rate of pCR was observed (16% vs 29%, p=0.03 and 16% vs 25%, p=0.01, respectively). Patients with both these characteristics had the lowest rate of pCR (10%, p=0.01). CONCLUSIONS - Anaemia is a negative predictive factor for tumor response in women treated with NST for BC. This evidence suggests that anaemia should be improved in order to improve response to NST
Geomorphological map of the NW Coast of the Island of Malta (Mediterranean Sea)
This paper presents the results of geomorphological investigations carried along the north-western coast of the Island of Malta. Field surveys, accompanied by aerial photo-intepretation, have led to the production of a geomorphological map at 1:7500 scale which outlines the main processes and related landforms. The latter are the result of the complex interplay of structural, gravitational, coastal and karst processes. Particular attention was devoted to the recognition, identification and mapping of landslides which affect large coastal sectors of the study area, locally giving rise to hazard conditions
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