An Algorithm for Network and Data-aware Placement of Multi-Tier Applications in Cloud Data Centers

Today's Cloud applications are dominated by composite applications comprising multiple computing and data components with strong communication correlations among them. Although Cloud providers are deploying large number of computing and storage devices to address the ever increasing demand for computing and storage resources, network resource demands are emerging as one of the key areas of performance bottleneck. This paper addresses network-aware placement of virtual components (computing and data) of multi-tier applications in data centers and formally defines the placement as an optimization problem. The simultaneous placement of Virtual Machines and data blocks aims at reducing the network overhead of the data center network infrastructure. A greedy heuristic is proposed for the on-demand application components placement that localizes network traffic in the data center interconnect. Such optimization helps reducing communication overhead in upper layer network switches that will eventually reduce the overall traffic volume across the data center. This, in turn, will help reducing packet transmission delay, increasing network performance, and minimizing the energy consumption of network components. Experimental results demonstrate performance superiority of the proposed algorithm over other approaches where it outperforms the state-of-the-art network-aware application placement algorithm across all performance metrics by reducing the average network cost up to 67% and network usage at core switches up to 84%, as well as increasing the average number of application deployments up to 18%.Comment: Submitted for publication consideration for the Journal of Network and Computer Applications (JNCA). Total page: 28. Number of figures: 15 figure

Free vibrations of simply-supported beam bridges under moving loads: Maximum resonance, cancellation and resonant vertical acceleration

The advent of high-speed railways has raised many concerns regarding the behaviour of bridges. Particularly, the analysis of the free vibrations generated by each load is of great interest because they can possibly accumulate and create resonance phenomena. Regarding simply supported beams, earlier contributions showed that the free vibrations created by a single moving force are of maximum or zero amplitude (cancellation) for certain speeds. In the present paper new closed-form expressions are given for the cancellation speeds of a generic mode, as well as for the most representative points of maximum amplitude. Similar new results are provided for elastically supported beams as well. A simpler, closed-form approximate expression of the cancellation condition for an elastically supported beam is also derived from the analysis of a single passing load; this approximate formula is in good agreement with the exact results. Knowing a priori the speeds of maximum free vibrations or cancellation is of great interest for experimental tests on bridges, particularly as regards the evaluation of amplitude-dependent magnitudes such as structural damping. Regarding the resonance phenomena, if the resonance speeds coincide with either a maximum free vibration or a cancellation speed, then a maximum resonance or a cancellation of resonance will occur. The most relevant cases thereof have been investigated, and new expressions which allow predicting them for a generic mode are given. Finally, a new approximate formula is proposed for estimating the maximum acceleration of simply supported bridges caused by resonances of the fundamental mode. After extensive numerical testing, the formula has proved to be a useful tool for a first assessment of simply supported bridges according to building codes such as Eurocodes. (C) 2012 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support of the State Secretariat for Research of the Spanish Ministry of Science and Innovation (Secretaria de Estado de Investigacion, Ministerio de Ciencia e Innovacion, MICINN) in the framework of the Research Project BIA2008-04111.Museros Romero, P.; Moliner, E.; Martinez-Rodrigo, M. (2013). Free vibrations of simply-supported beam bridges under moving loads: Maximum resonance, cancellation and resonant vertical acceleration. Journal of Sound and Vibration. 332(2):326-345. https://doi.org/10.1016/j.jsv.2012.08.008326345332

Secretion rates and protein composition of extracellular vesicles released by cancer-associated fibroblasts after radiation

Reciprocal communication between the malignant and non-malignant cellular elements in tumors is essential for cancer sustainability and plays an important role in the response of cancers to treatments. Some of this cellular crosstalk takes place via secretion of vesicles that are actively released into the extracellular space by most cell types in tumors. Recent studies have demonstrated radiation-induced changes in the secretion rate and composition of extracellular vesicles (EVs), with impact on radiation-related cellular communication. However, little is known about the effects of different radiation regimens on the release of EVs by cells of the tumor microenvironment. In this study, we provide a comprehensive molecular characterization of EVs released by cultured primary lung tumor fibroblasts. We explore the quantitative and morphological changes triggered by ionizing radiation (IR), delivered as a single dose of 18 Gy or three consecutive daily medium-doses of 6 Gy. Cancer-associated fibroblasts (CAFs) secrete EVs with sizes ranging from 80 to 200 nm, expressing some of the classical exosome markers. Exposing CAFs to a single-high radiation dose (1 × 18 Gy) or fractionated medium-dose did not alter the release of CAF-EVs. The protein composition of CAF-EVs was analyzed by LC-MS/MS proteomics and revealed that CAF-EVs are enriched with heat shock proteins, integrins, tetraspanins, proteinases, collagens, growth factors and an array of molecules involved in the regulation of cell migration and the immune system. Quantitative proteomic analyses revealed minor changes in the protein composition of CAF-EVs after radiation exposure. Taken together, this study presents original data on lung tumor CAF-EV composition and reveals that release and protein cargo of CAF-EVs are largely unaltered after exposing CAFs to IR

Immunobiology of cancer-associated fibroblasts in the context of radiotherapy

Radiotherapy (RT) still represents a mainstay of treatment in clinical oncology. Traditionally, the effectiveness of radiotherapy has been attributed to the killing potential of ionizing radiation (IR) over malignant cells, however, it has become clear that therapeutic efficacy of RT also involves activation of innate and adaptive anti-tumor immune responses. Therapeutic irradiation of the tumor microenvironment (TME) provokes profound cellular and biological reconfigurations which ultimately may influence immune recognition. As one of the major constituents of the TME, cancer-associated fibroblasts (CAFs) play central roles in cancer development at all stages and are recognized contributors of tumor immune evasion. While some studies argue that RT affects CAFs negatively through growth arrest and impaired motility, others claim that exposure of fibroblasts to RT promotes their conversion into a more activated phenotype. Nevertheless, despite the well-described immunoregulatory functions assigned to CAFs, little is known about the interplay between CAFs and immune cells in the context of RT. In this review, we go over current literature on the effects of radiation on CAFs and the influence that CAFs have on radiotherapy outcomes, and we summarize present knowledge on the transformed cellular crosstalk between CAFs and immune cells after radiation

Accurate Loss Prediction of Realistic Hollow-core Anti-resonant Fibers Using Machine Learning

Hollow-core anti-resonant fibers (HC-ARFs) have proven to be an indispensable platform for various emerging applications due to their unique and extraordinary optical properties. However, accurately estimating the propagation loss of nested HC-ARFs remains a challenging task due to their complex structure and the lack of precise analytical and theoretical models. To address this challenge, we propose a supervised machine-learning framework that presents an effective solution to accurately predict the propagation loss of a 5-tube nested HC-ARF. Multiple supervised learning models, including random forest, logistic regression, quadratic discriminant analysis, tree-based methods, extreme gradient boosting, and K-nearest neighbors are implemented and compared using a simulated dataset. Among these methods, the random forest algorithm is identified as the most effective, delivering accurate predictions. Notably, this study considers the impact of random structural perturbations on fiber geometry, encompassing random variations in tube wall thicknesses and tube gap separations. In particular, these perturbations involve randomly varying outer and nested tube wall thicknesses, tube angle offsets, and randomly distributed non-circular, anisotropic shapes within the cladding structure. It is worth noting that these specific perturbations have not been previously investigated. Each tube exhibits its unique set of random values, leading to longer simulation times for combinations of these values compared to regular random variables in HC-ARFs with similar tube characteristics. The comprehensive consideration of these factors allows for precise predictions, significantly contributing to the advancement of HC-ARFs for many emerging applications

Multi-stage generation of extreme ultraviolet dispersive waves by tapering gas-filled hollow-core anti-resonant fibers

In this work, we numerically investigate an experimentally feasible design of a tapered Ne-filled hollow-core anti-resonant fiber and we report the generation of multiple dispersive waves (DWs) in the range 90-120 nm, well into the extreme ultraviolet (UV) region. The simulations assume an 800 nm pump pulse with 30 fs 10 $\mu$J pulse energy, launched into a 9 bar Ne-filled fiber with $34~\mu$m initial core diameter that is then tapered to a $10~\mu$m core diameter. The simulations were performed using a new model that provides a realistic description of both loss and dispersion of the resonant and anti-resonant spectral bands of the fiber, and also importantly includes the material loss of silica in the UV. We show that by first generating solitons that emit DWs in the far-UV region in the pre-taper section, optimization of the following taper structure can allow re-collision with the solitons and further up-conversion of the far-UV DWs to the extreme-UV with energies up to 190 nJ in the 90-120 nm range. This process provides a new way to generate light in the extreme-UV spectral range using relatively low gas pressure

Robotic Resection of Intraductal Neoplasm of the Pancreas

Abstract Background: Minimally invasive techniques have been revolutionary and provide clinical evidence of decreased morbidity and comparable efficacy to traditional open surgery. Computer-assisted surgical devices have recently been approved for general surgical use. Aim: The aim of this study was to report the first known case of pancreatic resection with the use of a computerassisted, or robotic, surgical device in Latin America. Patient and Methods: A 37-year-old female with a previous history of radical mastectomy for bilateral breast cancer due to a BRCA2 mutation presented with an acute pancreatitis episode. Radiologic investigation disclosed an intraductal pancreatic neoplasm located in the neck of the pancreas with atrophy of the body and tail. The main pancreatic duct was enlarged. The surgical decision was to perform a laparoscopic subtotal pancreatectomy, using the da Vinci Ò robotic system (Intuitive Surgical, Sunnyvale, CA). Five trocars were used. Pancreatic transection was achieved with vascular endoscopic stapler. The surgical specimen was removed without an additional incision. Results: Operative time was 240 minutes. Blood loss was minimal, and the patient did not receive a transfusion. The recovery was uneventful, and the patient was discharged on postoperative day 4. Conclusions: The subtotal laparoscopic pancreatic resection can safely be performed. The da Vinci robotic system allowed for technical refinements of laparoscopic pancreatic resection. Robotic assistance improved the dissection and control of major blood vessels due to three-dimensional visualization of the operative field and instruments with wrist-type end-effectors

ALPPS Procedure with the Use of Pneumoperitoneum

ABSTRACT Background. A new method for liver hypertrophy was recently introduced, the so-called associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure. We present a video of an ALPPS procedure with the use of pneumoperitoneum. Methods. A 29-year-old woman with colon cancer and synchronous liver metastasis underwent a two-stage liver resection by the ALPPS technique because of an extremely small future liver remnant. Results. The first operation began with 30 min pneumoperitoneum. Anatomical resection of segment 2 was performed, followed by multiple enucleations on the left liver. The right portal vein was ligated and the liver partitioned. The abdominal cavity was partially closed, and a 10 mm trocar was left to create a pneumoperitoneum for additional 30 min. The patient had an adequate future liver remnant volume after 7 days, but she was not clinically fit for the second stage of therapy, so it was postponed. She was discharged on day 7 after surgery. The second stage took place 3 weeks later and consisted of an en-bloc right trisectionectomy extended to segment 1. The patient recovered and was discharged 9 days after second-stage surgery. Postoperative CT scan revealed an enlarged remnant liver. Conclusions. The ALPPS procedure is a new revolutionary technique that permits R0 resection even in patients with massive liver metastasis. The use of pneumoperitoneum during the first stage is an easy tool that may prevent hard adhesions, allowing an easier second stage. This video may help oncological surgeons to perform and standardize this challenging procedure. Surgical resection is the only curative modality of treatment in patients with colorectal liver metastases. Although multiple and bilobar metastases are correlated with the worst prognosis, this condition should not be considered a contraindication to hepatic resection, because even in this situation, surgery is still the only curative treatment. 1-3 The most common strategy for these patients is to perform neoadjuvant therapy followed by two-stage hepatectomy with minor resections on the left lateral liver (future liver remnant, FLR) combined with right portal vein occlusion as the first stage, followed by right trisectionectomy. 2 However, insufficient FLR volume may preclude liver resection even after portal vein occlusion. To overcome this problem, a new method to increase liver hypertrophy before extended hepatectomy was recently described by a German multicenter study and validated by the group of de Santibañes and Clavien

Multi-wavelength high energy gas-filled fiber Raman laser spanning from 1.53 um to 2.4 um

In this work, we present a high pulse energy multi-wavelength Raman laser spanning from 1.53 um up to 2.4 um by employing the cascaded rotational stimulated Raman scattering (SRS) effect in a 5-m hydrogen (H2) -filled nested anti-resonant fiber (NARF), pumped by a linearly polarized Er/Yb fiber laser with a peak power of ~13 kW and pulse duration of ~7 ns in the C-band. The developed Raman laser has distinct lines at 1683 nm, 1868 nm, 2100 nm, and 2400 nm, with pulse energies as high as 18.25 uJ, 14.4 uJ, 14.1 uJ, and 8.2 uJ, respectively. We demonstrate how the energy in the Raman lines can be controlled by tuning the H2 pressure from 1 bar to 20 ba