Needleless connectors:the way forward in the prevention of catheter-related infections?

Letter to the Editor

Full-field feed-forward equalizer with adaptive system optimization

We numerically investigate the combination of full-field detection and feed-forward equalizer (FFE) for adaptive chromatic dispersion compensation up to 2160 km in a 10 Gbit/s on-off keyed optical transmission system. The technique, with respect to earlier reports, incorporates several important implementation modules, including the algorithm for adaptive equalization of the gain imbalance between the two receiver chains, compensation of phase misalignment of the asymmetric Mach-Zehnder interferometer, and simplified implementation of field calculation. We also show that in addition to enabling fast adaptation and simplification of field calculation, full-field FFE exhibits enhanced tolerance to the sampling phase misalignment and reduced sampling rate when compared to the full-field implementation using a dispersive transmission line.

Low thermal sensitivity grating devices based on ex-45° tilting structure capable of forward-propagating cladding modes coupling

The authors describe a detailed investigation on tilted fiber Bragg grating (TFBG) structures with tilted angles exceeding 45°. In contrast to the backward mode coupling mechanism of Bragg gratings with normal and small tilting structures, the ex-45° TFBGs facilitate the light coupling to the forward-propagating cladding modes. The authors have also theoretically and experimentally examined the mode coupling transition of TFBGs with small, medium, and large tilt angles. In particular, experiments are conducted to investigate the spectra and far-field distribution, as well as temperature, strain, and refractive-index sensitivities of ex-45° devices. It has been revealed that these ex-45° gratings exhibit ultralow thermal sensitivity. As in-fiber devices, they may be superior to conventional Bragg and long-period gratings when the low thermal cross sensitivity is required. © 2006 IEEE.

Looking back or looking forward in corpus linguistics:what can the last 20 years suggest about the next?

Starting with a description of the software and hardware used for corpus linguistics in the late 1980s to early 1990s, this contribution discusses difficulties faced by the software designer when attempting to allow users to study text. Future human-machine interfaces may develop to be much more sophisticated, and certainly the aspects of text which can be studied will progress beyond plain text without images. Another area which will develop further is the study of patternings involving not just single words but word-relations across large stretches of text.

Sustainable energy systems for seawater reverse osmosis desalination

Desalination of seawater driven by solar and other sustainable energy sources could in principle fulfil the growing needs of the world's most water-stressed countries. Reverse osmosis (RO) has become the most efficient process for desalination, making it the technology of choice for use with solar energy, and photovoltaics (PV) has become the most successful technology for solar energy conversion. But despite recent gains in the efficiency of PV-RO, substantial improvements are still possible because of the numerous energy losses occurring between input of sunlight and output of freshwater. This chapter gives an overview of some of the research activities and recent advances that could ultimately result in solar-powered RO systems becoming more than 10 times efficient than today. It also describes advances in waste heat recovery for RO desalination that are yielding greatly improved performance over desalination processes based on distillation.

Outage-optimal relay strategy under outdated channel state information in decode-and-forward cooperative communication systems

In this study, the authors investigate the outage-optimal relay strategy under outdated channel state information (CSI) in a decode-and-forward cooperative communication system. They first confirm mathematically that minimising the outage probability under outdated CSI is equivalent to minimising the conditional outage probability on the outdated CSI of all the decodable relays' links. They then propose a multiple-relay strategy with optimised transmitting power allocation (MRS-OTPA) that minimises the conditional outage probability. It is shown that this MRS is a generalised relay approach to achieve the outage optimality under outdated CSI. To reduce the complexity, they also propose a MRS with equal transmitting power allocation (MRS-ETPA) that achieves near-optimal outage performance. It is proved that full spatial diversity, which has been achieved under ideal CSI, can still be achieved under outdated CSI through MRS-OTPA and MRS-ETPA. Finally, the outage performance and diversity order of MRS-OTPA and MRS-ETPA are evaluated by simulation.

Putting children forward for epilepsy surgery:a qualitative study of UK parents' and health professionals' decision-making experiences

Background Against a backdrop of recommendations for increasing access to and uptake of early surgical intervention for children with medically intractable epilepsy, it is important to understand how parents and professionals decide to put children forward for epilepsy surgery and what their decisional support needs are. Aim The aim of this study was to explore how parents and health professionals make decisions regarding putting children forward for pediatric epilepsy surgery. Methods Individual interviews were conducted with nine parents of children who had undergone pediatric epilepsy surgery at a specialist children's hospital and ten healthcare professionals who made up the children's epilepsy surgery service multidisciplinary healthcare team (MDT). Three MDT meetings were also observed. Data were analyzed thematically. Findings Four themes were generated from analysis of interviews with parents: presentation of surgery as a treatment option, decision-making, looking back, and interventions. Three themes were generated from analysis of interviews/observations with health professionals: triangulating information, team working, and patient and family perspectives. Discussion Parents wanted more information and support in deciding to put their child forward for epilepsy surgery. They attempted to balance the potential benefits of surgery against any risks of harm. For health professionals, a multidisciplinary approach was seen as crucial to the decision-making process. Advocating for the family was perceived to be the responsibility of nonmedical professionals. Conclusion Decision-making can be supported by incorporating families into discussions regarding epilepsy surgery as a potential treatment option earlier in the process and by providing families with additional information and access to other parents with similar experiences.

Kelet-közép-európai devizaárfolyamok előrejelzése határidős árfolyamok segítségével (Forecasting the exchange rates of three Central-Eastern European currencies with forward exchange rates)

Írásunkban azt vizsgáljuk, hogy a hosszú lejáratú határidős árfolyamok stacionaritását feltételező hibakorrekciós modellek, amelyeknek korábbi számítások szerint - a világ devizapiaci forgalmának mintegy 75 százalékát kitevő fejlett ipari országokra alkalmazva - kitűnő a mintán kívüli előrejelző erejük, hogyan képesek három keletközép- európai ország devizaárfolyamát előrejelezni. A három vizsgálat alá vont deviza (cseh, magyar, lengyel) esetében az eredmények relációnként nagyon eltérnek, és összességében kedvezőtlenebbek, mint a fejlett ipari országokra kapott eredmények, amit a nem teljesen rugalmas árfolyamrezsim, a rendelkezésre álló adatsor rövidsége, az eurózóna-csatlakozáshoz kapcsolódó bizonytalanságok, a devizakockázati és a határidős kamatprémium létezése, továbbá a Balassa-Samuelson-hatás együttes befolyásaként tudunk értelmezni. JEL kód: E43, F31, F47. /===/ This paper studies whether models that assume long-maturity forward exchange rates are stationary (which proved in earlier studies to provide superior forecasting ability when applied to exchange rates of major currencies) are capable of forecasting the Euro exchange rates of three Central-East European currencies (the Czech koruna, Hungarian forint and Polish zloty). The results for the three currencies differ from each other and are generally much worse than those obtained earlier for major currencies. These unfavourable results are attributed to the consequences of managed exchange-rate systems, to the short time series available, to uncertainties related to future Euro-zone entry, to the existence of a foreign exchange and term premium, and to the Balassa–Samuelson effect.

An ArcGIS Tool for Modeling the Climate Envelope with Feed-Forward ANN

This paper is about the development and the application of an ESRI ArcGIS tool which implements multi-layer, feed-forward artificial neural network (ANN) to study the climate envelope of species. The supervised learning is achieved by backpropagation algorithm. Based on the distribution and the grids of the climate (and edaphic data) of the reference and future periods the tool predicts the future potential distribution of the studied species. The trained network can be saved and loaded. A modeling result based on the distribution of European larch (Larix decidua Mill.) is presented as a case study.

Odüsszeuszi utazás – az előretekintő iránymutatás tapasztalatai = An Odysseian journey - experience with forward guidance

Az alsó kamatkorlát melletti előretekintő iránymutatás a kamatpolitika helyettesítője, a várakozások és a pénzpiaci hozamok befolyásolásának nem konvencionális monetáris politikai eszköze. A jegybank a piaci szereplők számára előre jelezheti az alacsony kamatkörnyezet tartós fennmaradását (delphoi típus), és kötelezettséget is vállalhat erre (odüsszeuszi típus). Ez utóbbi esetben megváltozik a jegybanki reakciófüggvény: a jegybanki kamatdöntésekben nem az inflációs kilátások és az inflációs cél közötti eltérés, illetve a kibocsátási rés jut kitüntetett szerephez, hanem valamilyen állapotváltozó alakulása vagy az időtényező. A reakciófüggvény változásának hitelessége esetén a hozamok csökkenésére lehet számítani. Ha a jegybank a kamatszint fenntartásának feltételéül az állapotváltozók olyan értékeit jelöli meg, amelyek teljesülése esetén az inflációs célkövetés szabályai szerint amúgy sem emelt volna kamatot, akkor az előretekintő iránymutatás „üres beszéd”, és a hozamokra gyakorolt hatás is elmaradhat. Egyelőre nem eldönthető, hogy az előretekintő iránymutatás a kamatpolitika átmeneti helyettesítőjéből annak tartós kiegészítő elemévé válik-e. _____ Forward guidance is a substitute for interest-rate policy where the zero lower boundary applies. It is an unconventional monetary policy instrument intended to influence market yields and expectations. The central bank may give signals (forecasts) to the market on lasting maintenance of a low interest-rate environment (Delphi type) or may commit itself to do so (Odysseus type). In the latter case the reaction function changes: instead of inflation prospects and output gap, the main role in central bank rate decisions becomes the evolution of given macroeconomic state variables or the time factor. If changes of the reaction function are credible, a drop in security yields are expected. Forward guidance is just cheap talk if such values in economic state variables are set as conditions for keeping interest rates unchanged, which based on the rules of inflation targeting would not trigger an interest rate increase, regardless. In that case, no impact on yields may occur. For the time being it cannot be decided whether forward guidance is transitory or a lasting instrument of monetary policy.

Detection of self-complementary inverted repeats by single forward primer driven PCR

Inverted repeat gene structures designed for silencing functional genes have been widely used both in academic and applied research. The correct orientations of such structures are usually validated with restriction analysis and/or sequencing. We speculated that the inverted repeat nature of such constructs can be shown by a simple PCR reaction with a single forward primer. To test this hypothesis five different constructs were established from grapevine sequences in a hairpin-intron style silencing system. We were able to amplify the appropriate products in each case. Thus a forward-primed PCR alone may be sufficient to prove the inverted repeat nature of the desired constructs.

A Look Back To Look Forward: New Patterns In The Supply/Demand Equation In The Lodging Industry

In his dialogue entitled - A Look Back to Look Forward: New Patterns In The Supply/Demand Equation In The Lodging Industry - by Albert J. Gomes, Senior Principal, Pannell Kerr Forster, Washington, D.C. What the author intends for you to know is the following: “Factors which influence the lodging industry in the United States are changing that industry as far as where hotels are being located, what clientele is being served, and what services are being provided at different facilities. The author charts these changes and makes predictions for the future.” Gomes initially alludes to the evolution of transportation – the human, animal, mechanical progression - and how those changes, in the last 100 years or so, have had a significant impact on the hotel industry. “A look back to look forward treats the past as prologue. American hoteliers are in for some startling changes in their business,” Gomes says. “The man who said that the three most important determinants for the success of a hotel were “location, location, location” did a lot of good only in the short run.” Gomes wants to make you aware of the existence of what he calls, “locational obsolescence.” “Locational obsolescence is a fact of life, and at least in the United States bears a direct correlation to evolutionary changes in transportation technology,” he says. “…the primary business of the hospitality industry is to serve travelers or people who are being transported,” Gomes expands the point. Tied to the transportation element, the author also points out an interesting distinction between hotels and motels. In addressing, “…what clientele is being served, and what services are being provided at different facilities,” Gomes suggests that the transportation factor influences these constituents as well. Also coupled with this discussion are oil prices and shifts in transportation habits, with reference to airline travel being an ever increasing method of travel; capturing much of the inter-city travel market. Gomes refers to airline deregulation as an impetus. The point being, it’s a fluid market rather than a static one, and [successful] hospitality properties need to be cognizant of market dynamics and be able to adjust to the variables in their marketplace. Gomes provides many facts and figures to bolster his assertions. Interestingly and perceptively, at the time of this writing, Gomes alludes to America’s deteriorating road and bridge network. As of right now, in 2009, this is a major issue. Gomes rounds out this study by comparing European hospitality trends to those in the U.S.

The Occupy Movement: Two Steps Forward, One Step Back

The op-ed evaluates the successes and limitations of the Occupy Movement in the United States. Ronald W. Cox argues that the Movement was inspirational in directing media focus to the trends of growing inequality and the privileges and power of the one percent. The critique of establishment parties and progressive organizations was a key part of the Occupiers efforts to rethink the meaning of social change. The limitations of the Movement became evident, however, in its extremely decentralized structures that emphasized consensus over majoritarian decision-making, and in its refusal to acknowledge and hold accountable its own leaders.