GKW representation theorem and linear BSDEs under restricted information. An application to risk-minimization

In this paper we provide Galtchouk-Kunita-Watanabe representation results in the case where there are restrictions on the available information. This allows to prove existence and uniqueness for linear backward stochastic differential equations driven by a general c\`adl\`ag martingale under partial information. Furthermore, we discuss an application to risk-minimization where we extend the results of F\"ollmer and Sondermann (1986) to the partial information framework and we show how our result fits in the approach of Schweizer (1994).Comment: 22 page

A stochastic control approach to public debt management

We discuss a class of debt management problems in a stochastic environment model. We propose a model for the debt-to-GDP (Gross Domestic Product) ratio where the government interventions via fiscal policies affect the public debt and the GDP growth rate at the same time.We allow for stochastic interest rate and possible correlation with the GDP growth rate through the dependence of both the processes (interest rate and GDP growth rate) on a stochastic factor which may represent any relevant macroeconomic variable, such as the state of economy. We tackle the problem of a government whose goal is to determine the fiscal policy in order to minimize a general functional cost. We prove that the value function is a viscosity solution to the Hamilton-Jacobi-Bellman equation and provide a Verification Theorem based on classical solutions. We investigate the form of the candidate optimal fiscal policy in many cases of interest, providing interesting policy insights. Finally, we discuss two applications to the debt reduction problem and debt smoothing, providing explicit expressions of the value function and the optimal policy in some special cases

A genome walking strategy for the identification of eukaryotic nucleotide sequences adjacent to known regions

Determination of nucleotide sequences adjacent to a known region is a recurring need in many genome scale studies. Various methods have been developed based on PCR techniques in order to fulfill th..

Up for Grabs: The State of Fossils Protection in (Recently) Unprotected National Monuments

On December 4, 2017, President Trump removed 2 million acres of land from the Bears Ears and Grand Staircase-Escalante national monuments. President Trump justified the reductions in part by claiming that many of the objects contained in the original monuments were already protected by other federal laws, and that the protections previously afforded to sixty-three percent of the land in the two original monuments were “unnecessary for the care and management of the objects to be protected within the monument[s].” This article explains why, contrary to the President’s assertions, plant and invertebrate fossils on the more than two million acres of land that were excluded from the monuments now receive less protection than when they were included in the monuments

PLATELET CONCENTRATE AND TISSUE REGENERATION: DOES IT WORK? A PRE-CLINICAL STUDY

During the last decades, the combination of cellular and molecular biology and mechanical engineering, has stimulated the development of new multidisciplinary fields in biomedical sciences, such as tissue engineering and regenerative medicine. The primary goal of these approaches is to provide an alternative to organ and tissue transplantation, by creating viable substitutes for damaged or diseased organs and tissues. Tissue healing is a complex process that involves a cascade of cellular and molecular events, that are mostly shared by the different tissues of the body. Interestingly, the tissue repair process initiates immediately after a traumatic injury and is mediated and controlled by a wide range of cytokines, proteins and growth factors released from platelets upon activation. Consequently, many growth factors have being considered as therapeutic molecules for the repair or regeneration of a wide range of tissues. Although their role has been only partially elucidated, the potential benefit of most growth factors has been demonstrated. In the last few years, the development of platelet-rich preparations has revolutionized the field of regenerative medicine, due to the repair capacities of the platelet-released growth factors, that stimulate and accelerate both soft and hard tissue healing and regeneration. Today, platelet concentrates are used in a wide range of disciplines such as dentistry, oral surgery, orthopedics, sport medicine, dermatology, and plastic and reconstructive surgery. Currently, different techniques to obtain these hemocomponents are available, each leading to preparations that may differ in platelet concentration, leukocyte and fibrin content. Among them, there is Plasma Rich in Growth Factors (PRGF), a preparation rich in platelets, easily obtained from a small volume of patient\u2019s blood, which, being autologous, does not promote any immune reaction and infectious disease transmission. Additionally, leukocytes are excluded from PRGF, so as to avoid any pro-inflammatory effects. Despite the growing craze for platelet concentrates technology, the scientific literature reported controversial results regarding the beneficial effect of these preparations on tissue healing, especially for bone regeneration. Considering all this information, the aim of our research was to developed a study model in order to gain more information about the biological effect of a platelet concentrate on both soft and hard tissue regeneration. For this purpose, human adipose-derived stem cells (hASCs), human osteoblasts (hObs) and human dermal fibroblasts (hDFs) cultured in the presence of PRGF, were studied. Usually, cells used for human therapy are expanded in fetal bovine serum (FBS), but this way carries the risk of potential immunogenic residual bovine proteins exposure and possible contamination with infectious agents, likely generating immune responses in patients. Therefore, in this study, FBS was completely substituted by the platelet concentrate for the cells culture. Interestingly, PRGF never affected cell viability and, after a short adaptation period, both hASCs and hDFs grown in the presence of PRGF, increased their proliferation rate compared to standard culture condition, while hObs growth was evident only without any cell\u2019s detachment. Furthermore, neither donor nor cell population effect on both cell viability and proliferation was observed. Regarding osteo-differentiation, alkaline phoshatase (ALP) activity was induced in both hASCs and hObs, with a peak at day 7 and 14, respectively. In parallel, in order to elucidate the clinical benefit of platelet concentrates in hard tissue repair, the combination of a bone graft substitute with PRGF in enhancing a bone defect regeneration performed in a preclinical animal model, was also investigated. In particular, bilateral circular critical lesions were created in the proximal tibia of six New Zealand rabbits, for a total of 12 defects, filled with the bone substitute alone or in association with PRGF. Untreated defects were also included as control. No side-effects have been observed during the 8 weeks follow-up. Both histological and histomorphometric analysis showed a non-significant difference between treatment groups in terms of bone density, even if the addition of PRGF to the bone substitute seemed to induce a higher percentage of newly formed bone. In conclusion, this in vitro and in vivo study provided the evidence of the beneficial effect of platelet concentrates in both soft and hard tissue regeneration, thus supporting the application of this technology in clinical regenerative therapies

JKarma: A Highly-Modular Framework for Pattern-Based Change Detection on Evolving Data

Pattern-based change detection (PBCD) describes a class of change detection algorithms for evolving data. Contrary to conventional solutions, PBCD seeks changes exhibited by the patterns over time and therefore works on an abstract form of the data, which prevents the search for changes on the raw data. Moreover, PBCD provides arguments on the validity of the results because patterns mirror changes occurred with any form of evidence. However, the existing solutions differ on data representation, mining algorithm and change identification strategy, which we can deem as main modules of a general architecture, so that any PBCD task could be designed by accommodating custom implementations for those modules. This is what we propose in this paper through jKarma, a highly-modular framework for designing and performing PBCD

Targeting tumor-associated macrophages to increase the efficacy of immune checkpoint inhibitors: a glimpse into novel therapeutic approaches for metastatic melanoma

Immune checkpoint inhibitors (ICIs) represent a promising therapeutic intervention for a variety of advanced/metastatic solid tumors, including melanoma, but in a large number of cases, patients fail to establish a sustained anti-tumor immunity and to achieve a long-lasting clinical benefit. Cells of the tumor micro-environment such as tumor-associated M2 macrophages (M2-TAMs) have been reported to limit the efficacy of immunotherapy, promoting tumor immune evasion and progression. Thus, strategies targeting M2-TAMs have been suggested to synergize with immune checkpoint blockade. This review recapitulates the molecular mechanisms by which M2-TAMs promote cancer immune evasion, with focus on the potential cross-talk between pharmacological interventions targeting M2-TAMs and ICIs for melanoma treatment