On the oldest asteroid families in the main belt

Asteroid families are groups of minor bodies produced by high-velocity collisions. After the initial dispersions of the parent bodies fragments, their orbits evolve because of several gravitational and non-gravitational effects,such as diffusion in mean-motion resonances, Yarkovsky and YORP effects, close encounters of collisions, etc. The subsequent dynamical evolution of asteroid family members may cause some of the original fragments to travel beyond the conventional limits of the asteroid family. Eventually, the whole family will dynamically disperse and no longer be recognizable. A natural question that may arise concerns the timescales for dispersion of large families. In particular, what is the oldest still recognizable family in the main belt? Are there any families that may date from the late stages of the Late Heavy Bombardment and that could provide clues on our understanding of the primitive Solar System? In this work, we investigate the dynamical stability of seven of the allegedly oldest families in the asteroid main belt. Our results show that none of the seven studied families has a nominally mean estimated age older than 2.7 Gyr, assuming standard values for the parameters describing the strength of the Yarkovsky force. Most "paleo-families" that formed between 2.7 and 3.8 Gyr would be characterized by a very shallow size-frequency distribution, and could be recognizable only if located in a dynamically less active region (such as that of the Koronis family). V-type asteroids in the central main belt could be compatible with a formation from a paleo-Eunomia family.Comment: 9 pages, 5 figures, 5 tables. Accepted for publication in MNRA

Limb amputation secondary to pseudoamniotic band syndrome after selective fetoscopic laser photocoagulation: case report

Pseudoamniotic band syndrome (PABS) is a rare iatrogenic complication that occurs after invasive procedures in monochorionic twins for treatment of twin-twin transfusion syndrome (TTTS). Selective fetoscopic laser photocoagulation (SFLP) is a commonly performed procedure for the treatment of severe TTTS that may lead to complications such as preterm labor, preterm rupture of membranes, cerebral lesions and fetal death. PABS has been reported to occur in up to 3% of cases of TTTS treated with laser, leading to limb abnormalities. There are no identifiable risk factors and antenatal detection of PABS is rare, but possible.  Thus, obstetricians should be aware of this possibility in pregnancies treated by laser therapy for TTTS.  The authors report a case of a monochorionic biamniotic twin pregnancy submitted to SFLP for TTTS at 19 weeks of gestation with postnatal diagnosis of PABS, presenting with amputation of a fetal limb.

Decrease in pulmonary function and oxygenation after lung resection

Respiratory deficits are common following curative intent lung cancer surgery and may reduce the patient's ability to be physically active. We evaluated the influence of surgery on pulmonary function, respiratory muscle strength and physical performance after lung resection. Pulmonary function, respiratory muscle strength (maximal inspiratory/expiratory pressure) and 6-min walk test (6MWT) were assessed pre-operatively, 2 weeks post-operatively and 6 months post-operatively in 80 patients (age 68±9 years). Video-assisted thoracoscopic surgery was performed in 58% of cases. Two weeks post-operatively, we found a significant decline in pulmonary function (forced vital capacity −0.6±0.6 L and forced expiratory volume in 1 s −0.43±0.4 L; both p<0.0001), 6MWT (−37.6±74.8 m; p<0.0001) and oxygenation (−2.9±4.7 units; p<0.001), while maximal inspiratory and maximal expiratory pressure were unaffected. At 6 months post-operatively, pulmonary function and oxygenation remained significantly decreased (p<0.001), whereas 6MWT was recovered. We conclude that lung resection has a significant short- and long-term impact on pulmonary function and oxygenation, but not on respiratory muscle strength. Future research should focus on mechanisms negatively influencing post-operative pulmonary function other than impaired respiratory muscle strength

Preparo da veia safena na cirurgia de revascularização miocárdica: uma nova técnica -no touch- que mantém a parede da veia íntegra e proporciona uma alta perviabilidade imediata

BACKGROUND: The technique of harvesting the saphenous vein (SV) for coronary artery bypass grafting (CABG) influences the fate of vein grafts. A new no touch (NT) technique of SV preparation was developed where the vein is harvested with a pedicle of surrounding tissue, which protects the vein from spasms therefore obviating the need for distension. METHOD: A prospective randomized study in 156 patients who underwent CABG was performed comparing three SV harvesting techniques. The techniques were conventional (c) (adventitial stripping of the vein, manual distention and storing in saline solution); Intermediate (I) (after adventitial stripping, the vein was left in situ, covered with a papaverine-soaked compress, and stored in heparinized blood); and no touch (SV dissected with its surrounding tissue was left in situ, covered with a saline-soaked compress and stored in heparinized blood). A morphological study of the endothelium was preformed using scanning electronic microscopy and an angiographic assessment of the vein graft patency was performed at 18 months mean follow-up time. Also an immunohistochemistry assessment was performed to identify the enzyme, nitric oxide synthase (NOS) in the vein wall. RESULTS: The preservation of the endothelial cell integrity was greater with the no touch technique than with the other procedures. At angiographic follow up, the patency for NT was 95.4%, 88.9% for grafts in group C and 86.2% for grafts in group I. The immunohistochemistry assessment revealed NOS in all three layers of the vein wall that was prepared by the no touch technique. However, a great reduction of this enzyme in veins treated by the conventional technique was observed. CONCLUSION: The endothelial integrity and NOS activity were better preserved when using the no touch technique for vein graft harvesting. The vasorelaxation and thrombo-resistant activities of nitric oxide (NO) may be responsible for the reduced of vasospasms and improved patency rate. Furthermore, the mechanical properties provided by the cushion of surrounding tissue in graft harvested by NT technique may contribute to the observed high patency rate.OBJETIVO: O objetivo deste trabalho é apresentar uma nova técnica no touch de preparo da veia safena e sua importância clínica. Esta nova técnica consiste na retirada da veia safena do seu leito, juntamente com um pedículo de tecido adiposo, protegendo a veia contra espasmos e, conseqüentemente, da necessidade de distendê-la durante a operação. MÉTODO: O estudo foi realizado em dois tempos: 1) Inicialmente, foi realizado um estudo prospectivo e randomizado, envolvendo 156 pacientes que foram submetidos à operação de revascularização miocárdica. Neste estudo nós comparamos a técnica no touch (NT) com duas outras: a convencional (C) e a intermediária (I). Foi feita uma avaliação detalhada da morfologia endotelial, utilizando a microscopia eletrônica, enquanto que a perviabilidade das pontes foi determinada com um exame angiográfico executado num período médio de 18 meses após a operação. 2) Finalmente, a enzima óxido nítrico síntase (NOS) foi identificada com ajuda do estudo imunohistoquímico e também pela localização auto-radiográfica de (3H)-L- Nitro-Arginina (NOARG). RESULTADOS: A avaliação morfológica mostrou integridade endotelial de 97% nas veias que foram tratadas pela técnica NT; enquanto quase metade da superfície endotelial das veias tratadas pelas outras duas técnicas exibiu ausência de células endoteliais. O exame angiográfico revelou perviabilidade de 95,4% para as pontes do grupo NT, 88,9% para as pontes do grupo (C) e 86,2% para as pontes do grupo (I). O estudo imunohistoquímico revelou a presença de NOS nas três camadas que compõem a parede da veia quando, as mesmas, foram tratadas pela técnica NT. Por outro lado, foi observada uma elevada redução desta enzima nas veias que foram tratadas pela técnica (C). A análise auto-radiográfica confirmou os resultados imunohistoquímicos. CONCLUSÃO: A integridade endotelial e a atividade da enzima óxido nítrico síntase foram melhor mantidas com o uso da técnica NT no preparo da veia safena. A atividade vasodilatadora e bloqueadora da agregação plaquetária causada pelo óxido nítrico (NO) pode ser a responsável pela proteção da veia contra o espasmo, como também pela alta perviabilidade imediata da mesma. Além disso, as propriedades mecânicas providas pelo tecido gorduroso em volta da veia, contribuíram para o melhor resultado desta nova técnica.University Hospital of Örebro Cardiothoracic Surgery DivisionUniversity Hospital Royal Free College Medical School Molecular Pathology and Biochemical DivisionHospital do Servidor Público EstadualUNIFESP Paulista Medical School Cardiothoracic Surgery DivisionHospital Oswaldo Cruz Cardiothoracic Surgery DivisionUNIFESP, Paulista Medical School Cardiothoracic Surgery DivisionSciEL

\u3cem\u3eTithonia diversifolia\u3c/em\u3e for Ruminant Nutrition

India and Brazil lead the world ranking of livestock enteric methane emissions (FAO 2006). According to FAO (2006), Brazil (9.6 Tg of CH4/year) is the highest emitter of methane from cattle, followed by India (8.6 Tg of CH4/year) and the USA (5.1 Tg of CH4/year). In livestock, methane (CH4) formed from enteric fermentation of carbohydrates is primarily responsible for the emissions in the sector. Regarding livestock methane emission, Delgado et al. (2012) evaluated 20 tree and shrub species using in vitro technique and demonstrated a reducing effect on the amount of methane when Tithonia diversifolia was compared with, for example, Cynodon nlemfuensis grass. Tithonia diversifolia belongs to the division - Sphermatophyta; class - Eudicotiledoneae; sub-class - Metaclamídeas; Order - Campanulate; Family - Asteraceae; Genre - Tithonia, and Species - Tithonia diversifolia (Hemsl.), Gray (Souza 2008). Tithonia diversifolia can be very useful in animal nutrition (Fig. 1) by increasing the protein content of animal diet at low cost (Murgueitio et al. 2010) as well as in the recovery of degraded soils for it grows in areas with low levels of fertility and has high ability to absorb phosphorus, even if it is unavailable to other forage species (Kwabiah et al. 2003). The objective of this study was to assess the nutritional qualities, including quantification of enteric methane generated during in vitro ruminal fermentation, of Tithonia diversifolia as an alternative forage for ruminant nutrition in the tropics

Effects of graphene oxide on aquatic macrophyte under the influence of humic substances.

The behavior of nanostructured graphene oxide (GO) in the environment is complex and must be completely understood to evaluate the risk involved. Studies show that humic acid (HA) can stabilize nanomaterials in water and change its behavior. The aquatic macrophyte duckweed (Lemna minor) is a good plant model for adverse effects evaluation of many test-materials due to its fast growth and small size. This study assessed the effect of GO, with and without HA, on the growth of L. minor on fronds number and biomass changes. The plants were exposed during 7 days to the nominal concentrations of GO equals to 0.0 (control), 0.1, 1.0, 10.0 and 100.0 mg L-1, in the absence or in the presence of 20 mg L-1 of HA. Tests were conducted in multiwell polystyreneplates where each well contained two fronds at the start of the experiment. The number of replicates for each test?concentration was 24 wells. The plants were exposed to a constant photoperiod (24:0, light:dark cycle) supplied by white fluorescent lamps (~700 lux) at the temperature of 20± 2 ºC. The fronds number was counted daily and the wet weight was assessed at the end of the experiment. The concentration that promoted 50% of inhibition in the growth rate in terms of fronds number (EC50-7d growth) and the concentration that promoted 50% of wet weight reduction (EC50-7d biomass) were calculated. The reduction of the growth rate by GO at the concentration of 100 mg L-1 was remarkable detected (P 100 mg L-1. This value attributes a practically non-toxicity for the test-material in terms of fronds production. On the other hand, the calculated EC50-7d biomass for the GO in the presence of HA or not was 2.8 and 2.4 mg L-1 respectively. These results indicate that the adverse effects of GO in L. minor are more pronounced on the biomass production since it was clearly observed that reductions in the fronds sizes were greater than in the fronds number. The EC50-7d biomass values assigns a moderate toxicity of GO to L. minor and these data may be useful for the establishment of maximum concentrations limits of this material in water bodies

Knowledge is at the Edge! How to Search in Distributed Machine Learning Models

With the advent of the Internet of Things and Industry 4.0 an enormous amount of data is produced at the edge of the network. Due to a lack of computing power, this data is currently send to the cloud where centralized machine learning models are trained to derive higher level knowledge. With the recent development of specialized machine learning hardware for mobile devices, a new era of distributed learning is about to begin that raises a new research question: How can we search in distributed machine learning models? Machine learning at the edge of the network has many benefits, such as low-latency inference and increased privacy. Such distributed machine learning models can also learn personalized for a human user, a specific context, or application scenario. As training data stays on the devices, control over possibly sensitive data is preserved as it is not shared with a third party. This new form of distributed learning leads to the partitioning of knowledge between many devices which makes access difficult. In this paper we tackle the problem of finding specific knowledge by forwarding a search request (query) to a device that can answer it best. To that end, we use a entropy based quality metric that takes the context of a query and the learning quality of a device into account. We show that our forwarding strategy can achieve over 95% accuracy in a urban mobility scenario where we use data from 30 000 people commuting in the city of Trento, Italy.Comment: Published in CoopIS 201

Local Salmonella immunostimulation recruits vaccine-specific CD8 T cells and increases regression of bladder tumor.

The efficacy of antitumoral responses can be increased using combinatorial vaccine strategies. We recently showed that vaccination could be optimized by local administration of diverse molecular or bacterial agents to target and augment antitumoral CD8 T cells in the genital mucosa (GM) and increase regression of cervical cancer in an animal model. Non muscle-invasive bladder cancer is another disease that is easily amenable to local therapies. In contrast to data obtained in the GM, in this study we show that intravesical (IVES) instillation of synthetic toll-like receptor (TLR) agonists only modestly induced recruitment of CD8 T cells to the bladder. However, IVES administration of Ty21a, a live bacterial vaccine against typhoid fever, was much more effective and increased the number of total and vaccine-specific CD8 T cells in the bladder approximately 10 fold. Comparison of chemokines induced in the bladder by either CpG (a TLR-9 agonist) or Ty21a highlighted the preferential increase in complement component 5a, CXCL5, CXCL2, CCL8, and CCL5 by Ty21a, suggesting their involvement in the attraction of T cells to the bladder. IVES treatment with Ty21a after vaccination also significantly increased tumor regression compared to vaccination alone, resulting in 90% survival in an orthotopic murine model of bladder cancer expressing a prototype tumor antigen. Our data demonstrate that combining vaccination with local immunostimulation may be an effective treatment strategy for different types of cancer and also highlight the great potential of the Ty21a vaccine, which is routinely used worldwide, in such combinatorial therapies