Protocol Research Articles

Cooperative Rate Adaption Scheme for Wireless Networks with Improved Fairness, Delay and Transmission Reliabi

We propose a Cooperative Rate Adaptation(CRA) MAC protocol based on the standard CSMA/CA pro tocol used in IEEE 802.11 wireles s networks. The proposal provide s cooperative error recovery, namely cooperative packet retransmission,while using rate adaptation. The transmission rate is selected based on the transmission rate history of theneighbours. The cooperating partner is selectedbased on a fuzzy logic selection algorithm. Three inputs are consideredin the fuzzy system: the average transmission rate of a neighbour, the erroneous packet ratioand the acknowledgedpacket ratio of a neighbour. The output of the fuzzy system is the partnership probability of aneighbour. In this paper, the protocol is compared to the non-cooperative rate adaptation scheme RBAR (Receiver Based Auto Rate) and to the cooperative rate adaptation scheme CRBAR (Cooperati ve Relay Based Auto Rate). The simulation results show that the proposed protocol improves the delay and packet delivery ratio while contributing to the transmission o portunity fairness among the terminals , regardless of their channel conditions.

Probabilistic data collection protocols for energy harvesting wireless sensor networks

Energy harvesting from ambient energy sources including solar and vibration has been studied as a candidate for powering next generation wireless sensor networks. However, energy harvesting is unstable to supply a sensor node with energy, and a node cannot know whether its neighbouring nodes have enough energy to receive a data packet. In this paper, we propose two data collection protocols for energy harvesting wireless sensor networks called the Probabilistic ReTransmission protocol (PRT) and PRT with Collision Consideration (PRT-CC). The idea is to derive the appropriate number of times to retransmit a packet based on the reception probability and the active intervals computed by the receivers themselves while, in PRT-CC, each node computes the reception probability with packet collision consideration. The performance evaluation shows that the proposed protocols are able to achieve higher delivery ratio than the previous work, namely, Geographic Routing with Duplicate Detection (GR-DD) and GR-DD with Retransmission.

Design of Team Economic Accounting Management System in Petrochemical Industry

Team economic accounting is the basis of enterprise economic accounting, and it is the main way to further implement the internal economic responsibility, reduce costs, improve economic efficiency, and enhance t he v iability o f the ent erprise. P etrochemical i ndustry eco nomic acco unting system is i n accordance with the development requirements of syst em engi neering. I t mak es the full use of development t heroy of sophisticated systems to put forward the design ideas. T he system uses DNA-based th ree-tier archi tecture, the back-end database is Oracle 8i, and in termediate tem porary data is Access. Mean while, it chose Delphi as its development tools, and access data through ODAC and ADO technology. So it can collect, organize and transmit instrument data in time under different types of DCS communication prot ocol to meet the need s for t he i nquires of dynamic t eam cost accounting and dynamic cost information. Nowadays, the system has been formally launched and has good results in many aspects such as improve efficiency, reduce raw material waste and cost control, and so on.

Client-Based Network-Assisted Mobile IPv6

With the growing number of mobile nodes and projections that this number will far exceed that o f stationary nodes, mobility management becomes an important aspect of the next generation networks. Mobile operators are therefore looking to deploy a functional and optimized protocol that all ows management of mobility while offering additional functionaliti es, such as simultaneous multi-access and flow mobility (important for Fixed- Mobile Convergence (FMC) for instance). Two major protocols exist that offer mobility management for Internet P rotocol (IP) networks, Mobile IPv6 (MIPv6) and Proxy Mobile IPv6 (PMIPv6). However, both protocols have shortcomings that hinder their deployment on a massive scale. We therefore propose a new protocol, based on the current MIPv6 specifications , that addresses these shortcomings. It can be seen as a hybrid prot ocol offering simultaneously client and network mobility managements, which can be labeled client-based network-assisted. We compare it to the existing two protocols and show that it doesn't suffer from their drawbacks.

Real-Time PCR Reveals Endosymbiont Titer Fluctuations inMetaseiulus occidentalis(Acari: Phytoseiidae) Colonies Held at Different Temperatures

Real-time PCR (Polymerase Chain Reaction) can estimate Wolbachia endosymbiont population density in mosquitoes (Wiwatanaratanabutr & Kittayapong 2009). The COS (?arbaryl-OP-Sul fur resistant) colony of the phytoseiid Metaseiulus (=Typhlodromus or Gcdendromus) occidentalis (Nesbitt) harbors several endosymbionts, includ ing Cardinium, Wolbachia, Enterobacter, and Bacteroidetes in their gut and reproductive tis sues (Johanowicz & Hoy 1996; Hoy & Jeyaprakash 2005). Johanowicz & Hoy (1998) ob served mating incompatibility when females from a heat-treated (33?C) COS colony (a treatment presumed to eliminate Wolbachia) was crossed with males from a room-temperature (23?C) COS colony containing Wolbachia, resulting in the pro duction of shriveled eggs that did not hatch. It was not clear whether the Wolbachia population was reduced or completely eliminated from the heat-treated mites because a standard PCR pro tocol was used, which is relatively insensitive compared to high-fidelity PCR (Jeyaprakash & Hoy 2000). In this paper, we estimate the endo symbiont population density in COS colonies of M. occidentalis held under different tempera tures in the laboratory using real-time PCR. One colony of M. occidentalis was maintained at room-temperature (23-25?C) and 2 colonies ini tiated from this line were maintained at 32 and 34?C for More than 1 year in growth chambers prior to experiments. Female mites (100) were isolated from each colony and their genomic DNA extracted by Puregene and QIAGEN methods (Jeyaprakash & Hoy 2007), and resuspended in 50 pL of sterile water. Four different plasmids carrying endosymbiont 16S rRNA sequences; pAJ233 (Cardinium), pAJ234 (Bacteroidetes), pAJ235 (Wolbachia) and pAJ239 (Enterobacter), were extracted and their yield estimated with a BioPhotometer Plus (Eppendorf AG, Hamburg, Germany). Species-specific primers were de signed with Primer 3 software (http:// frodo.wi.mit.edu/primer3/) and a probe was de signed with Primer X software (Applied Biosys tems, Foster City, CA) from the variable regions for each species (Table 1). Real-time PCR was per formed in a 20-pL reaction volume containing ge nomic DNA from 2 females (1 pL) or serially-di luted plasmid DNA (100 pg to 1 fg) or a no DNA control (1 pL), forward and reverse primers (400 pM), probe (100 pM) and TaqMan master mix (10 pL). Two linked profiles: (1) one cycle of 50?C for 2 min and 95?C for 10 min, and (2) 60 cycles consist ing of denaturation at 95?C for 15 s, annealing at 59?C (Cardinium) or 57?C (Wolbachia or Entero bacter or Bacteroidetes) for 30 s and extension at 72?C for 30 s, were used. Each treatment was rep l cated 3 times. The starting copy number of all plasmid DNA dilutions used in the real-time PCR was obtained with an open-source software (http:/

Integrated Metric-Ad Hoc On-Demand Distance Vector: A Routing Protocol over Wireless Mesh Networks

Problem statement: Wireless Mesh Networks (WMNs) is an emerging technology for wireless environment. Since WMNs are permanent or semi-permanent network, an efficient and reliable path establishment is the core concern for such type of networks. Several performance metrics has been designed for WMNs such as Expected Transmission Count (ETX), Expected Transmission Time (ETT), interference Aware Routing Metric (iAWARE), Link Type Aware (LTA) Metric, Success Probability Product (SPP) and so on. However, each of these individual routing metric considered some selected features thus a single metric is inad equate for selecting the most reliable path. Consequently, it is necessary to integrate multiple performance metrics into a routing protocol to att ain optimal performance. Approach: In this study we proposed a technique of integrati ng multiple metrics to improve the performance of a WMN routing protocol. This technique was implemented in Ad hoc On-Demand Distance Vector (AODV) routing protocol thus leading to the development of Integrated Metrics AODV (IM-AODV) routing protocol. Results: The simulation results indicated that IM- AODV protocol significantly outperformed the tradit ional AODV in WMNs environment. In a lightly loaded network the performance of IM-AODV is almost similar to AODV, however, in moderate to highly loaded network the performance of IM-AODV was improved by 10% (on average) compared to AODV. Conclusion/Recommendations: Incorporating multiple metrics in a routing protoc ol proved an effective mechanism for selecting the best path in a multi-hop wireless network (e.g. WMN) with loop free routing and avoiding highly loaded and lo ssy links. The proposed integrated metric scheme can also be considered for other routing protocols with simple modifications.

Registering protocols for studies of test accuracy with BJOG

Last year BJOG set up facilities for clinical researchers to register their randomised controlled trial protocols for electronic publication early in the research process. The idea was to encourage good research practice and to make it more likely that the published results reflected the truth. We are now offering the same facility for studies of test accuracy. We believe that we are the first journal to offer this facility for primary research into test accuracy. Studies of test accuracy can go wrong in all sorts of ways. Authors may fail to define the population under investigation, the test, the cutoff values or their reference standard before they start data collection. Some patients may miss some tests, undergo different ones or not get the reference standard. Finally, the results may not be analysed and presented in ways that clinicians can understand and act on. If any of these things go wrong, or get changed halfway through, it makes it almost impossible to interpret the results. The requirements for reporting test accuracy studies are widely agreed but they are more likely to be met if they are considered and published before starting. Protocol registration makes the whole research process more transparent. If sample sizes, cutoff values or reference standard definitions are altered at any stage, referees can see what has happened and judge whether it may have affected the results. If protocols never get published because editors are biased towards selecting papers with positive results, this will also be clear. To register a test accuracy protocol (PT), visit our Web site at http://bjog.allentrack.net and follow instructions. On pages 847–848, and on the Web site, we publish suggested headings for such protocols which authors are free to follow, although we do not insist on this. Protocols will be sent to referees who will use these headings for evaluation. Accepted protocols will be published electronically on BJOG online and a summary printed in the journal. We hope that the main study publication would be submitted first to BJOG and we promise to send it to referees. If their reports are satisfactory, we would normally agree to publish the study, although we cannot guarantee this at the registration stage.

The key to curbing unintentional weight loss lies in identifying the problem

The study entitled ″Medical Nutrition Therapy (MNT) for the Prevention and Treatment of Unintentional Weight Loss (UWL) in Residential Health Care Facilities,” conducted by Patricia Splett, Lori Roth-Yousey, and Jody Vogelzang, examines unplanned weight loss and its treatment in newly admitted patients in the first 180 days upon arrival in residential health care facilities. One of the most important results of the study is the identification of UWL in newly admitted patients. ″Similar outcomes for usual care (UC) and MNT protocol (PC) groups when UWL was identified indicate that usual nutrition care was already a high standard of care for intervention.” If this is true, then great importance is placed on the standards in identifying UWL. If nutritional consultation to health care facilities is rare, the identification and, obviously, the treatment of UWL becomes a difficult task. The study concludes, ″nutrition care protocols with standardized weighing procedures can increase the identification of UWL in the residential health care environment.”

Inter-rater reliability of the STEP protocol.

An inter-rater reliability test of the Stepwise Comparative Status Analysis (STEP) is presented. The STEP is a protocol for the clinical examination of patients with dementia, within the scope of a neuropsychiatric investigation. It combines psychiatric and neurologic bedside examination methods. The analysis is made in three steps where primary, observable symptom variables are successively aggregated via compound variables to the final determination of one of seven possible dominant regional brain syndromes (global, frontal, subcortical, parietal, frontosubcortical, frontoparietal, other), here also called complex variables. In the present study, two senior physicians assessed 50 patients independently and simultaneously. None of the patients was known to both physicians. In 42 patients (84%), the same dominant brain syndrome was determined by the two clinicians. The probability (P value) of this (or better) agreement was calculated at 2.0 x 10(-12). Kappa coefficients were calculated as a measure of assessment agreement regarding the 50 STEP variables. For 20 variables, the coefficient was 0.75 or above, indicating excellent agreement; for 22 variables, the coefficient was below 0.75 and above 0.40, indicating moderate agreement; and for 4 variables, the value was 0.40 or below, indicating poor agreement. Kappa calculations regarding the assessments of four variables were either not possible or were considered inappropriate.

Performance Analysis of a Multicast Protocol for Wireless Environments

This paper presents a performance study, using both analytical modeling and simulation techniques, of a new end-to-end reliable multicast protocol for use in environments with wireless access. The proposed pro tocol, called the reliable mobile multicast protocol (RM2), divides a multicast tree into sub-trees where subcasting is applied within the relatively smaller regions using a hierarchical tree of retransmission servers (RSs). RM2 is receiver-oriented in that the transmitter does not need to know its receivers, hence offering better scalability. The Internet Group Management Protocol is used to manage group membership whereas the IETF's Mobile IP offers support to user mobility through a temporary IP address. Each RS has a retransmission subcast ad dress shared by its members which may be dynamically configured using allocation schemes such as the IETF's MADCAP. More important, RM2 uses a dynamic re transmission strategy to switch between multicast and unicast retransmission modes according to the amount of extra load generated in the network and in the wire less interfaces by packet retransmissions. It is shown through analytical modeling and simulation that RM2's dynamic adaptation is not only important but also necessary when considering mobile wireless access.

Individualized outcome feedback produces voluntary antiemetic prescribing practice changes

Study Objective: To determine the impact of individualized outcome feedback on antiemetic prescribing practices and compare outcomes of a cost-effective, standardized antiemetic protocol (PROT) to that of customized antiemetic therapy (NONPROT). Design: Prospective, observational study with randomized component. Setting: Postanesthesia care unit (PACU) of an academic medical center. Patients: 3027 consecutive ASA physical status I, II, and III patients receiving general anesthesia. Interventions: Patients were randomized to receive 0.625 mg droperidol or 4 mg ondansetron for postoperative nausea and/or vomiting (PONV) from a protocol, or received customized antiemetic therapy. Measurements and Main Results: Incidence of PACU PONV, selection of PROT versus NONPROT, patient satisfaction, and use of PONV prophylaxis were measured and indexed by an attending anesthesiologist in a monthly report for 4 months. Monthly expenditures for antiemetic therapy prior to, during, and after the study were collected. Literature on PONV outcomes, appropriate timing, and selection of PONV prophylaxis was distributed. The NONPROT group was slightly older than the PROT group; otherwise, demographics were similar between all groups. The incidence of PONV did not differ between the PROT and NONPROT groups (11% vs. 10%), and the incidence of PONV in patients receiving prophylaxis was higher in both groups (17% PROT vs. 15% NONPROT). Patients receiving ondansetron as a first-line drug required rescue therapy less often (5%) than those receiving droperidol (14%); however, patient satisfaction was indistinguishable among all groups. During the study, the use of prophylaxis decreased 47% without an increase in PONV, and PROT selection increased 54%. Conclusions: Individualized outcome feedback produced a 48% reduction in monthly expenditures for ondansetron and droperidol, which was sustained after the study. Patients satisfaction between ondansetron 4 mg and droperidol 0.625 mg given in the PACU did not differ in spite of a slightly greater efficacy of ondansetron as a first-line drug.

New Anticoagulants for the Cardiovascular Patient

Manuscript received May 9, 1994; accepted July 7, 1994. Address correspondence and reprint requests to Dr. Jeanine M. Walenga, Department of Pathology, Loyola University Med ical Center, 2160 South First Avenue, Maywood, IL 60153, U.S.A. Summary: Invasive cardiac procedures and cardiac sur gery, which have become a significant component of health care, provide a particular case scenario where there are special considerations given to control bleeding and to have available alternative anticoagulants for pa tients unable to tolerate heparin (e.g., heparin-induced thrombocytopenia). We describe a comprehensive proto col for blood preservation in cardiac surgery incorporat ing the patient's medical history, autologous transfusions, and intraoperative techniques of heparin and protamine titration and dosing. Furthermore, various new anticoag ulants under clinical development are discussed, particu larly hirudin, hirulog, iloprost, ancrod, Lomoparan, low- molecular-weight heparins, 1-deamino-8-D-arginine- vasopressin (DDAVP), and aprotinin. These approaches should benefit the patient with difficult to control periop erative bleeding, heparin-induced thrombocytopenia, al lergic reactions to protamine, platelet dysfunction, and poor response to heparin (e.g., due to antithrombin III deficiency).

Purification of Rickettsiales-like organisms associated with Pecten maximus (Mollusca Bivalvia): serological and biochemical characterization

Significant mortalities have been observed in populations of Saint-Jacques scallops Pecten maximus, in association with numerous intracellular colonies of Rickettsiales-like organisms (RLO) in the gills. Isolation of the procaryotes from infected tissues and their subsequent purification were achieved by a specifie proto col based on differential and isopycnic centrifugations on sucrose and renografin density gradients. The purity and integrity of purified procaryotes were verified by electron mieroscopy. Specifie polyclonal antibodies were prepared for serological characterization. Fifteen major constituent proteins were electrophoretieally identified, their molecular weights ranging between 148 and 16 kD. Ten enzyme activities were biochemically identified, including acid phosphatase and catalase, which could be related to procaryote pathogenicity.

Interacting Successfully in Corporate Culture

To assume their roles in corporate culture, business- and technical- communication students must understand the spoken and unspoken dis courses of corporate protocol and be aware of the intricacies of these discourses. Students must be knowledgeable about the correct corporate proto col for verbal as well as for nonverbal communication. Teachers can incorpo rate exercises into business- and technical-communication courses to increase students' awareness of and competence in navigating institutional politics. Learning how to interact successfully will enable students as new employees not only to survive institutional politics but to advance in their professions.

Complications of Laser-Assisted Angioplasty: Recognition, Classification and Treatment

No adequate reports from signifi cant patient populations exist on the nature and extent of complications from peripheral laser-assisted angio plasty. To define and enumerate these adverse reactions, data were col lected from 770 procedures per formed on 400 patients in a sixteen- month period. Arteries treated were: 133 iliac (17%), 418 femoral (54%), 121 popliteal (16%), 73 tibial/pero neal (9%), and 25 grafts (3%). Complications, similar to those of standard angioplasty, were identified and classified according to cause: la ser, access method, or the angioplasty procedure with its attendant equip ment (balloons, etc). The types of morbidity observed were: perfora tion/dissection (54 cases, 7%), acute thrombosis (38, 5%), spasm (5, 0.7%), false aneurysm at the punc ture site (15, 2%), embolism (1, 0.1%), and hematoma (115, 15%). Because perforation is the most significant intraoperative complica tion, a standardized system has been devised to bring uniformity to its doc umentation and reporting. The three-part classification is based on the arterial pathology producing the probe's deviation and on the ramifi cations of the aberrancy. In addition to recognition and classification, prudent treatment of an evolving complication can often salvage the procedure. Treatment modalities for the common complica tions and preventive measures to avert them have been identified and incorporated into the treatment pro tocol.

Expert vs novice decision making in accounting: A summary

Considerable effort is spent each year teaching students (novices) how to use accounting information, and how to make financial decisions. However, very little is object ively known about what differentiates exper t from novice decision making. This study compares the decision making processes of exper ts and novices in the context of a financial analysis task. It employs and extends a pro tocol analysis, or process tracing methodology, which has successfully been used in task domains such as physics and medicine The focus of the study is on detai led decision making behavior, thereby identifying the specific strategies and processes that are used by the exper t and the novice. The specific data collect ion approach used in the exper iment involved asking decision makers to verbalize during their financial analysis, and tape-recording their verbalizations. The resulting transcripts, called concurrent or thinking-aloud protocols, provide the data for the pro tocol analysis.