Decomposition theorems and extension principles for hesitant fuzzy sets

We prove a decomposition theorem for hesitant fuzzy sets, which states that every typical hesitant fuzzy set on a set can be represented by a well-structured family of fuzzy sets on that set. This decomposition is expressed by the novel concept of hesitant fuzzy set associated with a family of hesitant fuzzy sets, in terms of newly defined families of their cuts. Our result supposes the first representation theorem of hesitant fuzzy sets in the literature. Other related representation results are proven. We also define two novel extension principles that extend crisp functions to functions that map hesitant fuzzy sets into hesitant fuzzy sets

Oncosurgical approach to colorectal liver metastases

Spitalul Universitar Vall d'Hebron, Departamentul Chirurgie HBP şi Transplantologie, Barcelona, Spania, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Rezumat: Pacienţii cu metastaze hepatice din cancerul colorectal (CCR) reprezintă o provocare majoră în sănătatea publică cu aproximativ 1,2 milioane cazuri de CCR anual în lume. Rezecţia metastazelor hepatice de origine colorectală (MHCR) este singurul tratament care oferă posibilitatea de vindecare şi a prezentat beneficii clare de supravieţuire. Totuşi, doar 10-20% din pacienţii cu MHCR sunt eligibili de această procedură în avans. Pe parcursul ultimii decade, au avut loc progrese esențiale în managementul MHCR care vizează trei domenii: oncologia, radiologia şi chirurgia. Aceste progrese au condus la creşterea ratei de rezecţie până la 20-30% din cazuri cu o supravieţuire de 35-50% la 5 ani. Tratamentul neoadjuvant cu aşa preparate chemoterapeutice ca irinotecanul şi oxaliplatina şi preparate biologice (bevacizumab, cetuximab, panitumumab) are un rol important în creşterea numărului de pacienţi eligibili pentru rezecţie secundară. Numărul sau dimensiunea metastazelor sau chiar prezenţa bolii rezecabile extrahepatice nu trebuie să mai fie o contraindicaţie absolută, iar durata chimioterapiei trebuie să fie cât mai scurtă pentru a ajunge la rezecţie imediat, ce este posibil din punct de vedere tehnic în absenţa progresului tumorii. În această situaţie, cel puţin patru cure de chimioterapie de primă linie trebuie administrate, cu verificarea răspunsului tumorii la fiecare 2 luni. Creşterea interesului în aşa marcheri moleculari ca KRAS şi BRAF, de asemenea va ajuta în stratificarea populaţiei cu identificarea de pacienţi pentru terapia ţintă. În această revistă a literaturii, noi descriem strategiile oncochirurgicale curente utilizate la pacienţii cu MHCR rezecabile şi non-rezecabile pentru a facilita atingerea rezecţiei R0 care include embolizarea venei porte, hepatectomia pe etape şi hepatectomia prin ablaţie cu radiofrecvenţă, beneficiile acestora, cât şi strategiile viitoare de tratament. În concluzie, participarea unei echipe multidisciplinare în tratamentul MHCR este esenţială pentru îmbunătăţirea rezultatelor clinice şi de supravieţuire.Summary: Patients with liver metastases from colorectal cancer (CRC) present a major public health challenge with approximately, 1.2 million cases of CRC occur yearly worldwide. Resection of colorectal liver metastases (CRLM) is the only treatment offering the possibility of cure and has been shown to provide clear survival benefits. However, only 10 to 20% of patients with CRLM are eligible for this procedure upfront. During the last decade, major advances in the management of CRLM have taken place involving three fields: oncology, radiology and surgery. These advances have increased the resectability rate to 20-30% of cases with a 5-year survival of 35-50%. Neoadjuvant treatment with chemotherapeutic agents such as irinotecan and oxaliplatin, and biologic agents (bevacizumab, cetuximab, panitumumab) play an important role in increasing the number of patients eligible to secondary resection. The number or size of metastases or even the presence of resectable extrahepatic disease should not be longer an absolute contraindication, and the duration of chemotherapy should be as short as possible to achieve the resection as soon as technically possible in the absence tumour progression. In this situation, at least four courses of first-line chemotherapy should be given, with assessment of tumour response every 2 months. Increasing interest in predictive molecular markers, such as KRAS and BRAF, will also help stratify patient populations to targeted therapy. In this review, we have described the current oncosurgical strategies employed in patients with resectable and non resectable CRLM to help achieve R0 resection including portal vein embolization, staged hepatectomies, and hepatectomies with radiofrequency ablation, their benefits, and future treatment strategies. In conclusion, multidisciplinary team for the treatment of CRLM is essential for improving clinical and survival outcomes

The spatial distribution of O-B5 stars in the solar neighborhood as measured by Hipparcos

We have developed a method to calculate the fundamental parameters of the vertical structure of the Galaxy in the solar neighborhood from trigonometric parallaxes alone. The method takes into account Lutz-Kelker-type biases in a self-consistent way and has been applied to a sample of O-B5 stars obtained from the Hipparcos catalog. We find that the Sun is located 24.2 +/- 1.7 (random) +/- 0.4 (systematic) pc above the galactic plane and that the disk O-B5 stellar population is distributed with a scale height of 34.2 +/- 0.8 (random) +/- 2.5 (systematic) pc and an integrated surface density of (1.62 +/- 0.04 (random) +/- 0.14 (systematic)) 10^{-3} stars pc^{-2}. A halo component is also detected in the distribution and constitutes at least ~5% of the total O-B5 population. The O-B5 stellar population within ~100 pc of the Sun has an anomalous spatial distribution, with a less-than-average number density. This local disturbance is probably associated with the expansion of Gould's belt.Comment: 14 pages, 3 figures, to appear in the May 2001 issue of the Astronomical Journa

A new Wolf-Rayet star in Cygnus

We report the discovery of a new Wolf-Rayet star in the direction of Cygnus. The star is strongly reddened but quite bright in the infrared, with J = 9.22, H = 8.08 and K = 7.09 (2MASS). On the basis of its H + K spectrum, we have classified WR 142a a WC8 star. We have estimated its properties using as a reference those of other WC8 stars in the solar neighbourhood as well as those of WR 135, whose near-infrared spectrum is remarkably similar. We thus obtain a foreground reddening of A(V) = 8.1 mag, M(J) = -4.3, log(L/Lo) = 5.0 - 5.2, R = 0.8 Ro, T = 125,000 K, M = 7.9 - 9.7 Mo, and a mass loss of (1.4 - 2.3)e-05 Mo/yr. The derived distance modulus, DM = 11.2 +/- 0.7 mag, places it in a region occupied by several OB associations in the Cygnus arm, and particularly in the outskirts of both Cygnus OB2 and Cygnus OB9. The position in the sky alone does not allow us to unambiguously assign the star to either association, but based on the much richer massive star content of Cygnus OB2 membership in this latter association appears to be more likely

Spatial and temporal stability of weed patches in cereal fields under direct drilling and harrow tillage

The adoption of conservation agriculture (CA) techniques by farmers is changing the dynamics of weed communities in cereal fields and so potentially their spatial distribution. These changes can challenge the use of site-specific weed control, which is based on the accurate location of weed patches for spraying. We studied the effect of two types of CA (direct drilling and harrow-tilled to 20 cm) on weed patches in a three-year survey in four direct-drilled and three harrow-tilled commercial fields in Catalonia (North-eastern Spain). The area of the ground covered by weeds (hereafter called “weed cover”) was estimated at 96 to 122 points measured in each year in each field, in 50 cm × 50 cm quadrats placed in a 10 m × 10 m grid in spring. Bromus diandrus, Lolium rigidum, and Papaver rhoeas were the main weed species. The weed cover and degree of aggregation for all species varied both between and within fields, regardless of the kind of tillage. Under both forms of soil management all three were aggregated in elongated patterns in the direction of traffic. Bromus was generally more aggregated than Lolium, and both were more aggregated than Papaver. Patches were stable over time for only two harrow-tilled fields with Lolium and one direct-drilled field with Bromus, but not in the other fields. Spatial stability of the weeds was more pronounced in the direction of traffic. Herbicide applications, crop rotation, and traffic seem to affect weed populations strongly within fields, regardless of the soil management. We conclude that site-specific herbicides can be applied to control these species because they are aggregated, although the patches would have to be identified afresh in each season.This research was funded by the Spanish National Program (project: AGL2010-22084-C02-0). A.E.M. was funded by the Institute Strategic Programme (ISP) grants, “Soils to Nutrition” (S2N) grant number BBS/E/C/000I0330, and the joint Natural Environment Research Council (NERC) and Biotechnology and Biological Sciences Research Council (BBSRC) ISP grant “Achieving Sustainable Agricultural Systems” (ASSIST) grant number BBS/E/C/000I0100, using facilities funded by the BBSRC

Can ketogenic dietary interventions slow disease progression in ADPKD : what we know and what we don't

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease leading to kidney failure. To date there is no cure for the disease although there is one approved disease modifying therapy, tolvaptan. In this context, a common question that ADPKD patients ask in clinical practice is whether there is anything they can do to slow their disease by modifying their diet or lifestyle. Recent evidence from experimental PKD models has shown the potential benefits of caloric restriction, high water intake and especially ketogenic diets in preserving kidney function. Whether these benefits are translatable to humans remains unknown

Disrupted Lipid Metabolism in Multiple Sclerosis: A Role for Liver X Receptors?

Multiple sclerosis (MS) is a chronic neurological disease driven by autoimmune, inflammatory and neurodegenerative processes leading to neuronal demyelination and subsequent degeneration. Systemic lipid metabolism is disturbed in people with MS, and lipid metabolic pathways are crucial to the protective process of remyelination. The lipid-activated transcription factors liver X receptors (LXRs) are important integrators of lipid metabolism and immunity. Consequently, there is a strong interest in targeting these receptors in a number of metabolic and inflammatory diseases, including MS. We have reviewed the evidence for involvement of LXR-driven lipid metabolism in the dysfunction of peripheral and brain-resident immune cells in MS, focusing on human studies, both the relapsing remitting and progressive phases of the disease are discussed. Finally, we discuss the therapeutic potential of modulating the activity of these receptors with existing pharmacological agents and highlight important areas of future research

A New Nearby Candidate Star Cluster in Ophiuchus at d = 170 pc

The recent discoveries of nearby star clusters and associations within a few hundred pc of the Sun, as well as the order of magnitude difference in the formation rates of the embedded and open cluster populations, suggests that additional poor stellar groups are likely to be found at surprisingly close distances to the Sun. Here I describe a new nearby stellar aggregate found by virtue of the parallel proper motions, similar trigonometric parallaxes, and consistent color-magnitude distribution of its early-type members. The 120 Myr-old group lies in Ophiuchus at $d$ $\simeq$ 170 pc, with its most massive member being the 4th-magnitude post-MS B8II-III star $\mu$ Oph. The group may have escaped previous notice due to its non-negligible extinction ($A_V$ $\simeq$ 0.9 mag). If the group was born with a normal initial mass function, and the nine B- and A-type systems represent a complete system of intermediate-mass stars, then the original population was probably of order $\sim$200 systems. The age and space motion of the new cluster are very similar to those of the Pleiades, $\alpha$ Per cluster, and AB Dor Moving Group, suggesting that these aggregates may have formed in the same star-forming complex some $\sim10^8$ yr ago.Comment: 23 pages, 3 figs., to appear in Nov. 2006 A