Leveraging probabilistic reasoning in deterministic planning for large-scale autonomous Search-and-Tracking

Search-And-Tracking (SaT) is the problem of searching for a mobile target and tracking it once it is found. Since SaT platforms face many sources of uncertainty and operational constraints, progress in the field has been restricted to simple and unrealistic scenarios. In this paper, we propose a new hybrid approach to SaT that allows us to successfully address large-scale and complex SaT missions. The probabilistic structure of SaT is compiled into a deterministic planning model and Bayesian inference is directly incorporated in the planning mechanism. Thanks to this tight integration between automated planning and probabilistic reasoning, we are able to exploit the power of both approaches. Planning provides the tools to efficiently explore big search spaces, while Bayesian inference, by readily combining prior knowledge with observable data, allows the planner to make more informed and effective decisions. We offer experimental evidence of the potential of our approach

Deterministic versus Probabilistic Methods for Searching for an Evasive Target

Several advanced applications of autonomous aerial vehicles in civilian and military contexts involve a searching agent with imperfect sensors that seeks to locate a mobile target in a given region. Effectively managing uncertainty is key to solving the related search problem, which is why all methods devised so far hinge on a probabilistic formulation of the problem and solve it through branch-and-bound algorithms, Bayesian filtering or POMDP solvers. In this paper, we consider a class of hard search tasks involving a target that exhibits an intentional evasive behaviour and moves over a large geographical area, i.e., a target that is particularly difficult to track down and uncertain to locate. We show that, even for such a complex problem, it is advantageous to compile its probabilistic structure into a deterministic model and use standard deterministic solvers to find solutions. In particular, we formulate the search problem for our uncooperative target both as a deterministic automated planning task and as a constraint programming task and show that in both cases our solution outperforms POMDPs methods

Boosting search guidance in problems with semantic attachments

Most applications of planning to real problems involve complex and often non-linear equations, including matrix operations. PDDL is ill-suited to express such calculations since it only allows basic operations between numeric fluents. To remedy this restriction, a generic PDDL planner can be connected to a specialised advisor, which equips the planner with the ability to carry out sophisticated mathematical operations. Unlike related techniques based on semantic attachment, our planner is able to exploit an approximation of the numeric information calculated by the advisor to compute informative heuristic estimators. Guided by both causal and numeric information, our planning framework outperforms traditional approaches, especially against problems with numeric goals. We provide evidence of the power of our solution by successfully solving four completely different problems

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

Bone Marrow Foot Oedema in Adolescents: The Role of Vitamin D

BACKGROUND: Bone marrow oedema (BMO) in children/adolescents is a rare clinical condition without an etiologic cause. It is associated with typical increased signal intensity on T2-weighted magnetic resonance images (MRI) and an increase in bone turnover in which vitamin D plays a pivotal role. No treatment guidelines for these young patients are to date available. METHODS: We performed a retrospective study in a pediatric setting of 13 patients with diagnosis of primary BMO of the foot on the basis of clinical and radiological findings. Data collection included sex, age, patient history, symptoms at presentation, clinical examination, laboratory bone turnover markers, vitamin D levels, MRI, treatment, and outcome. RESULTS: Vitamin D deficiency or insufficiency was found in 76.9% of cases. All patients were treated with adequate vitamin D daily intake, a short course of analgesic therapy, physical therapy, avoiding detrimental feet and ankle immobilization. All fully recovered in 3-month lag period. CONCLUSIONS: Our data highlight that environmental factors, such as underestimated articular or bone microtraumatisms, as well as joint hyper mobility, in a bone turnover milieu of vitamin D deficiency could be the cause of this clinical conditions. Adequate vitamin D supplementation, associated with physical and analgesic therapy, is crucial in the management of BMO

Altered expression of antioxidant enzymes and autophagic proteins in transglutaminase 2 knockout mice

""Background. Transglutaminases (TGs) are ubiquitous calcium-dependent acyl-transferases, catalysing post-translational protein modifications. Among the family members, TG2 (or "tissue" transglutaminase) acts as a multifunctional protein regulating cell processes, including autophagy [1,2]. . TG2 is highly expressed in the nervous tissue and reportedly involved in neurodegenerative disorders [3]. Indeed, the pathophysiology of these diseases includes insoluble aggregate formation, and covalent cross-linking of pathogenic proteins by TG2 has been suggested. Another hallmark of neurodegeneration is dysregulated autophagy, thus making the role played by TG2 in this cellular process especially relevant. Interestingly, conditions promoting TG2 activity, such as low GTP and high calcium levels, associated with oxidative stress, occur in neurodegeneration. . The present study aims to clarify the role of TG2 in redox balance and autophagy. To this purpose, the expression levels of antioxidant enzymes and pro-autophagic proteins were investigated in various brain regions and liver of TG2-\\\/- mice. . . Materials and methods. Expression of antioxidant enzymes, namely superoxide dismutase 1 and 2 (SOD1, SOD2), catalase (CAT) and glutathione peroxidase 1 (GPX1), and autophagic proteins (Beclin1, LC3 and AMBRA1) were evaluated by Western blotting (WB) and immunohistochemistry in selected brain areas (neocortex, hippocampus, brainstem, and cerebellum) and liver of 12-month-old TG2-\\\/- and wild-type mice.. . Results. WB and immunohistochemical data reveal altered expression patterns of antioxidant enzymes in both liver and brain tissues. Of particular interest is the statistically significant decrease of CAT and SOD2 in the cerebellum and hippocampus of TG2-\\\/- mice, while unchanged levels of these proteins are detected in the neocortex and brainstem. In the knockout liver, even more dramatic reduction of CAT and SOD2 expression is found, while SOD1 is intriguingly upregulated. Concerning the effect of TG2 deletion on autophagy, Beclin1 is down-regulated in the neocortex and hippocampus of knockout mice.. . Conclusions. Overall, our data on TG2-\\\/- mice support the involvement of the transamidating enzyme in controlling redox balance of different organs, and in regulating autophagic flux [1-3]. The specific decrease in the peroxisomal enzyme CAT and in the mitochondrial protein SOD2 emphasizes the role of these organelles in oxidative stress management and their interplay in cell metabolism. Moreover, region-based differences in the effect of TG2 deletion may reflect multiple functions related to the organ, tissue and cell type.. "

Validation of the American Joint Committee on Cancer new prognostic stage groups for HER2-positive breast cancer patients treated with adjuvant chemotherapy and trastuzumab in the prospective ShortHER trial

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Second-generation nitazoxanide derivatives: thiazolides are effective inhibitors of the influenza A virus

Aim: The only small molecule drugs currently available for treatment of influenza A virus (IAV) are M2 ion channel blockers and sialidase inhibitors. The prototype thiazolide, nitazoxanide, has successfully completed Phase III clinical trials against acute uncomplicated influenza. Results: We report the activity of seventeen thiazolide analogs against A/PuertoRico/8/1934(H1N1), a laboratory-adapted strain of the H1N1 subtype of IAV, in a cell culture-based assay. A total of eight analogs showed IC50s in the range of 0.14–5.0 μM. Additionally a quantitative structure–property relationship study showed high correlation between experimental and predicted activity based on a molecular descriptor set. Conclusion: A range of thiazolides show useful activity against an H1N1 strain of IAV. Further evaluation of these molecules as potential new small molecule therapies is justified