Resolution of ranking hierarchies in directed networks

Identifying hierarchies and rankings of nodes in directed graphs is fundamental in many applications such as social network analysis, biology, economics, and finance. A recently proposed method identifies the hierarchy by finding the ordered partition of nodes which minimises a score function, termed agony. This function penalises the links violating the hierarchy in a way depending on the strength of the violation. To investigate the resolution of ranking hierarchies we introduce an ensemble of random graphs, the Ranked Stochastic Block Model. We find that agony may fail to identify hierarchies when the structure is not strong enough and the size of the classes is small with respect to the whole network. We analytically characterise the resolution threshold and we show that an iterated version of agony can partly overcome this resolution limit.Comment: 27 pages, 9 figure

Adrenomedullin in pancreatic carcinoma. a case-control study of 22 patients

Pancreatic carcinoma is a leading cause of cancer-related death. Reduction of the diagnostic delay is mandatory. Adrenomedullin (AM) is overexpressed in pancreatic cancer. A case-control study including 12 patients with pathological diagnosis of pancreatic carcinoma and 10 healthy controls was conducted at our Institution. Blood samples were obtained at the time of hospitalization and post-operatively for cases. Controls’ samples were obtained from healthy volunteers. AM was measured by using enzyme immunoassay method. AM showed significant increase in pancreatic carcinoma patients vs controls (4.51 ng/ml vs 1.91 ng/ml, p value = 0.04) regardless of tumor stage, differentiation, resecability/unresecability, diabetes. A cut-off of 1.75 ng/ml reaches a sensibility of 83% and a specificity of 70% (p value = 0.0147; CL 95%; AUC 0.767). The increase of AM didn’t correlate with the increase of other common tumor markers (CA 19-9 and CEA), nor direct bilirubin. These data confirm the utility of studying the role of AM in pancreatic cancer, in order to achieve an early diagnosis in high risk populations

Whole-brain vasculature reconstruction at the single capillary level

The distinct organization of the brain’s vascular network ensures that it is adequately supplied with oxygen and nutrients. However, despite this fundamental role, a detailed reconstruction of the brain-wide vasculature at the capillary level remains elusive, due to insufficient image quality using the best available techniques. Here, we demonstrate a novel approach that improves vascular demarcation by combining CLARITY with a vascular staining approach that can fill the entire blood vessel lumen and imaging with light-sheet fluorescence microscopy. This method significantly improves image contrast, particularly in depth, thereby allowing reliable application of automatic segmentation algorithms, which play an increasingly important role in high-throughput imaging of the terabyte-sized datasets now routinely produced. Furthermore, our novel method is compatible with endogenous fluorescence, thus allowing simultaneous investigations of vasculature and genetically targeted neurons. We believe our new method will be valuable for future brain-wide investigations of the capillary network

The biological properties of OGI surfaces positively act on osteogenic and angiogenic commitment of mesenchymal stem cells

Osteogenesis process displays a fundamental role during dental implant osteointegration. In the present work, we studied the influence of Osteon Growth Induction (OGI) surface properties on the angiogenic and osteogenic behaviors of Mesenchymal Stem cells (MSC). MSC derived from dental pulp and HUVEC (Human Umbilical Vein Endothelial Cells) were grown in on OGI titanium surfaces, and cell proliferation and DNA synthesis were evaluated by MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] test and DNA quantification. Gene expression has been performed in order to evaluate the presence of mRNA related to endothelial and osteogenesis markers. Moreover, morphological and biochemical analyses of osteogenesis commitments has been performed. On OGI surfaces, MSC and HUVEC are able to proliferate. Gene expression profiler confirms that MSC on OGI surfaces are able to express endothelial and osteogenic markers, and that these expression are higher compared the expression on control surfaces. In conclusion On OGI surfaces proliferation, expression and morphological analyses of angiogenesis-associated markers in MSC are promoted. This process induces an increasing on their osteogenesis commitmen

Unconditional adoption rules out the need for parent–offspring recognition in a single‐brooded colonial seabird

Parent–offspring recognition (POR) is fundamental in colonial birds when the potential intermingling of chicks is higher due to the large number and proximity of nests. In species with isolated nests, where chick presence in the nest is strong contextual evidence of kinship, there might be circumstances when the parent might doubt the identity of the chick, but not enough to reject it. Olfactory-based recognition of conspecifics and nest sites in birds has gained strong evidence suggesting a potential role of olfaction in POR. Despite that, there are no studies testing it. We used Scopoli's shearwater (Calonectris diomedea) as model colonial single-brooded species with a developed olfactory sense, usually breeding in well-spaced nests with low probability of chicks mixing. We tested the parent's ability to selectively respond to their own chick as opposed to a simpler rule of feeding any chick found in the nest by means of chick-fostering experiments. We designed two cross-fostering experiments using chicks of different ages to test whether the ability of parents to recognize a related chick develops over time, possibly after acquiring an own distinctive odour. Finally, we also manipulated nests’ odour to disentangle the confounding effect of nest site recognition from POR when parents return at night. All experimental chicks were adopted by parents as the weight and bill growth of cross-fostered chicks did not differ significantly from the control group. We recorded a small difference in weight when foster chicks were inside an odour-manipulated nest; although we did not record weight loss in experimental chicks, only a steeper increase in weight was observed in control chicks. In conclusion, adoption in Scopoli's shearwater seems to follow the rule "if the young is in my nest, accept it" proposed by Beecher (1991) for species with spatially separated nests and low chick mobility.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/acceptedVersio

Editorial Disease of Adrenal Glands

International audienceThe adrenal gland has been historically an object of interest and scientific curiosity. This is also due to its very heterogeneous structure, number of hormones, complex neural innervation, and multiple and different physiological functions. The adrenal gland also entails an outstanding example of paracrine interactions occurring between histogenetically different tissues as the cortex and the medulla. This special issue is a great opportunity for the reader to learn the latest and emerging findings on the pathophysiol-ogy, diagnosis, and treatment of the adrenal glands disorders. The issue provides a variety of excellent articles covering a broad and contemporary spectrum of aspects of the diseases of the adrenal gland. Of particular interest and novelty is the interplay between hormones of the adrenal glands and other organs, such as the adipose tissue, the endothelium, the bone, and even the brain. In addition to the well-established effects on lipid and glucose metabolism, the hormones of the adrenal glands display a fascinating cross talk with the adipose tissue [1– 3]. The interaction between the adrenals and adipokines is extensively discussed by A. Y. Kargi and G. Iacobellis in a comprehensive and updated review paper. The potential of the fat depot surrounding the adrenal tumors to act like a brown adipose tissue (BAT) is a rapidly emerging topic that will certainly deserve further attention and investigation [4]. Interestingly the authors provided a theoretical basis for potential future pharmacological interventions aimed at adrenal hormone targets in the adipose tissue. Primary aldosteronism is the most common endocrine cause of arterial hypertension. It can cause excess damage to the organs that are target of hypertension and higher cardiometabolic risk [5]. This contention was supported by previous experimental data obtained by Karl Weber's group in rats infused with aldosterone, which exhibited hypercalciuria and raised parathyroid hormone (PTH) levels [6], and, more importantly, by findings in patients with aldosterone-producing adenoma who also showed elevated serum PTH levels that were then normalized by adrenalectomy [7]. The effect of the adrenal hormones on bone metabolism in patients with primary aldosteronism is nicely addressed by L. Petramala et al. The authors sought to test the hypothesis that hyperaldosteronism may influence mineral homeostasis through higher urinary calcium excretion leading eventually to secondary hyperparathyroidism. Of further interest, G. Mazzocchi et al. showed that PTH stimulates aldosterone secretion in a concentration-dependent manner [8], a finding that was complemented by the demonstration of the miner-alocorticoid receptor in the human parathyroid cells [9]. It is well established that a substantial amount of sodium is bound to proteoglycans of bone, connective tissue, and cartilage and that the osmotic force created by the high sodium concentration maintains the high water content in the latter tissue, allowing it to withstand high pressures during exercise [10]. In this special issue P. Alonso et al. further expand on the relationships between the adrenal gland and the skeleton by showing a reduction in the bone mineral densit

A case of acute aortic dissection type b associated with cushing's syndrome

We report a case of a 63-year-old man, with a previous history of hypertension and glucose intolerance associated troncular obesity that was emergently admitted to our Institution for evaluation of a severe, constant posterior chest pain which radiated anteriorly and dyspnoea with a suspected diagnosis of acute aortic dissection. A CT scan of thorax and abdomen demonstrated a dissection starting just below left succlavian artery and extending downward to the left renal artery, involving the celiac tripod and superior mesenteric artery. The dissection was classified as Stanford B, De Bakey III. Moreover, CT scan of abdomen revealed incidentally a left adrenal tumor of 25 mm of diameter. An emergent prosthetic graft was placed just below the origin of the left succlavian artery up-to the diaphragmatic hiatus. Furthermore, a diagnostic evaluation of the mass revealed an increase of cortisol production, and a diagnosis of Cushing's syndrome was done and the patient underwent an adrenalectomy via laparotomic approach. We report an association of acute aortic dissection of acute aortic dissection type B associated to Cushing's syndrome. Cushing's syndrome; Adrenocortical adenoma; Aortic dissection type B

A Paradigm Shift: Supply Chain Collaboration and Competition in and between Europe’s Chemical Clusters

With the attention of the chemical industry focused on exploiting the low cost feedstocks in the Middle East and the growth markets of Brazil, Russia, India, China and South East Asia, this report provides a timely reminder to policy makers, chemical companies and logistics service providers of the significant opportunities for improving business potential in Europe’s chemical clusters. Europe is still the largest, most sophisticated global market for chemical products, with a well developed, efficient, highly productive asset base, sound infrastructure, leading edge research and development and significant purchasing power. Provided these advantages are sustained, including continued attention to asset maintenance and operational and supply chain improvements, Europe can remain a competitive force in the global market place, despite what the doom-mongers may say to the contrary. ..