Follicular bisection in hair transplantation surgery: an in vitro model

The aim of this study was to evaluate, in an in vitro model, the survival and growth rates of transversely sectioned human hair follicles to assess experimentally the soundness of this approach as a future possible method for "duplicating" available donor hair grafts in hair transplantation procedures. A total of 300 human anagen hair follicles was obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 100 follicles), cultured intact as dissected, and group B (experimental; n = 200 follicles), transversely transected, parallel to the epidermal surface and immediately below the bulge area, to obtain 200 lower-half follicles and 200 upper-half follicles. Isolated hair follicles from both groups were maintained in culture for 10 days. The length of each follicle was measured immediately following isolation and at the end of the 10-day culture period. No statistically significant differences were found between the growth rate of intact follicles (mean 10-day growth rate = 2.71 mm) and of lower-half follicles (mean 10-day growth-rate = 2.64 mm), whereas a statistically significant difference was found between the growth rate of follicles from the two above-mentioned groups and the growth rate of the "upper-half" follicles (mean 10-day growth rate = 1.07 mm). Histologic analysis demonstrated that both intact and lower-half follicles maintained a normal histologic appearance, whereas in upper-half follicle sections we invariably detected a region of intense cell proliferation, reminiscent of a regenerated follicular papilla, surrounding the lowermost part of the follicle. In our opinion, the reported in vitro survival rate of transected human hair follicles might represent an interesting starting point in striving to augment the number of donor hairs available during a hair transplantation procedure.     

An ellipsoidal off-line MPC scheme for uncertain polytopic discrete-time systems

An off-line Model Predictive Control (MPC) method based on ellipsoidal calculus and viability theory is described in order to address control problems in the presence of state and input constraints for uncertain polytopic linear plants subject to persistent disturbances. In order to reduce the computational burdens and conservativeness of traditional polytopic MPC schemes, the present approach carries out off-line most of the computations and it makes use of closed-loop predictions to improve the control performance. This is done by recursively pre-computing suitable ellipsoidal inner approximations of the exact controllable sets and solving on-line a simple and numerically low-demanding optimization problem subject to a set-membership constraint. Comparisons with three other recent off-line MPC approaches are also provided in the final example.     

Clustering heteroskedastic time series by model-based procedures

Financial time series are often characterized by similar volatility structures. The detection of clusters of series displaying similar behavior could be important in understanding the differences in the estimated processes, without having to study and compare the estimated parameters across all the series. This is particularly relevant when dealing with many series, as in financial applications. The volatility of a time series can be characterized in terms of the underlying GARCH process. Using Wald tests and the Autoregressive metrics to measure the distance between GARCH processes, it is shown that it is possible to develop a clustering algorithm, which can provide three classifications (with increasing degree of deepness) based on the heteroskedastic patterns of the time series. The number of clusters is detected automatically and it is not fixed a priori or a posteriori. The procedure is evaluated by simulations and applied to the sector indices of the Italian market.     

Runtime Techniques to Enable a Highly-Scalable Global Address Space Model for Petascale Computing

Over the past decade, the trajectory to the petascale has been built on increased complexity and scale of the underlying parallel architectures. Meanwhile, software developers have struggled to provide tools that maintain the productivity of computational science teams using these new systems. In this regard, Global Address Space (GAS) programming models provide a straightforward and easy to use addressing model, which can lead to improved productivity. However, the scalability of GAS depends directly on the design and implementation of the runtime system on the target petascale distributed-memory architecture. In this paper, we describe the design, implementation, and optimization of the Aggregate Remote Memory Copy Interface (ARMCI) runtime library on the Cray XT5 2.3 PetaFLOPs computer at Oak Ridge National Laboratory. We optimized our implementation with the flow intimation technique that we have introduced in this paper. Our optimized ARMCI implementation improves scalability of both the Global Arrays programming model and a real-world chemistry application—NWChem—from small jobs up through 180,000 cores.     

Lung Microbiome in Idiopathic Pulmonary Fibrosis and Other Interstitial Lung Diseases

Interstitial lung diseases represent a heterogeneous and wide group of diseases in which factors leading to disease initiation and progression are not fully understood. Recent evidence suggests that the lung microbiome might influence the pathogenesis and progression of interstitial lung diseases. In recent years, the utilization of culture-independent methodologies has allowed the identification of complex and dynamic communities of microbes, in patients with interstitial lung diseases. However, the potential mechanisms by which these changes may drive disease pathogenesis and progression are largely unknown. The aim of this review is to discuss the role of the altered lung microbiome in several interstitial lung diseases. Untangling the host–microbiome interaction in the lung and airway of interstitial lung disease patients is a research priority. Thus, lung dysbiosis is a potentially treatable trait across several interstitial lung diseases, and its proper characterization and treatment might be crucial to change the natural history of these diseases and improve outcomes.     

意大利遗址公园规划设计探究——以罗马图拉真考古遗址公园为例

遗址公园作为遗址保护、展示教育与考古研究的有效途径，在世界范围内得以广泛推广与发展。意大利在文化遗产保护领域走在世界前列，其完备的法律保护制度、成熟的遗产保护理念和文物保护技术都有一定的借鉴意义。以罗马图拉真遗址公园为例，通过对其历史沿革的梳理，从遗址的空间结构和历史时序性上解读遗址时空特性，探讨其在坚持遗址原真性的基础上，如何从遗址保护理念、规划设计策略和实施技术路径3个层面对遗址进行保护与阐释，旨在解析意大利在遗址公园规划设计中的理念与方法，探讨其对于遗址公园建设实践的价值。     

Preferential CO oxidation over Pt/3A zeolite catalysts in H2-rich gas for fuel cell application

Even traces of CO in the hydrogen-rich gas fed to proton exchange membrane fuel cells (PEMFC) poison the platinum anode electrode and dramatically decrease the cell power output. In this work, several 1%Pt catalysts, all on 3A-type zeolite support, were prepared starting from different precursors and employing different methods: cation exchange (CE), wet impregnation (WI) and incipient wetness impregnation (IWI). The catalysts were characterised in terms of platinum dispersion and tested under realistic conditions in the quest of a catalyst for the removal of CO via the CO preferential oxidation (CO-PROX) reaction. The best catalytic performance was shown by the 1%Pt–3A catalyst prepared by IWI starting from Pt(NH₃)₄Cl₂ as a precursor, thanks to its highest platinum dispersion.     

Energy savings and better performances through variable speed drive application in desalination plant brine blowdown pump service

Brine blowdown represents an essential service for thermal desalination (both MSF and MED) and its operation is linked to the overall process reliability and availability.

Even if the brine blowdown pump represents a relatively minor utility in MSF plants, this utility is often the object of a service of very delicate nature. Different options are available in the market to design the blowdown pumping system, reducing EPC and operating costs and increasing reliability.

In this paper, the use of variable speed drive has been analysed for a centrifugal pump brine blowdown service in a desalination plant application. Today, the price of variable speed drive up to 250 kW is lower than 10 years ago, allowing the application of these devices in industrial applications with no price increase for the customer.

Due to the particular nature of the service (level regulation inside evaporator), the combination of low head and large capacity imposes the selection of high Nq hydraulics with consequently a flat performance curve. Under these conditions, regulation by throttling is awkward because a small variation in the system losses results in a large variation of pumped quantity. Moreover, high Nq hydraulics show a relatively narrower operating range that increases the regulation problem.

Therefore, the centrifugal pump selection is difficult because the machine works badly when too far away from the design point and, thus, the use of an inverter associated to the pump’s electric motor could allow to regulate the pump speed according to the pump requested performances. This solution improves performance because it allows the machine to work not too far away from the best efficiency point thus reducing power absorption. In addition, the pump works at BEP with less vibration and requires less maintenance over time.

Briefly, the main characteristics of the most used pump in this kind of service have been analysed and a simple type of control logic has been proposed. Furthermore, the present paper aims at overviewing the different project options, comparing costs and taking corrective actions on the factors causing operational troubles.     

H∞ generalized minimum sensitivity control design

This paper presents a two-stage approach to the H_∞ generalized sensitivity minimization problem (H_∞-GSM) for SISO, continuous-time plants. Besides some possible advantages in the control law evaluation with respect to alternative polynomial methods, the proposed approach provides a direct link with the solution of an underlying generalized minimum variance (H₂-GMV) problem and allows one to identify the class of the joint H₂/H_∞-GMV (equalizing H₂-GMV) optimal controllers.     

Comparison and optimization of different methods of evaluation of displacements in cracked reinforced concrete beams

The evaluation of deflections of reinforced concrete beams is strongly affected by the cracking of concrete; in order to develop a correct calculation of deflections, it is necessary to define an adequate tension stiffening model and exact, prediction of the values of cracking moment and of Young's modulus of elasticity. In this paper, the different models of tension stiffening and the semi-empirical correlations for evaluating the modulus of rupture and the Young's modulus are synthetically described and compared with each other. The analytical deflections computed by means of different models are compared with the experimental results obtained by different authors, and an optimization analysis is developed in order to improve the CEB and ACI models.