CiteULike: Tag cc

V3A Processes Contour Curvature as a Trackable Feature for the Perception of Rotational Motion

Caplovitz — 2007-04-14T11:51:26-00:00

Cerebral Cortex, Vol. 17, No. 5. (15 May 2007), pp. 1179-1189.

Crystallography of complexes

Skarzynski — 2006-12-13T13:09:09-00:00

Acta Crystallographica Section D: Biological Crystallography, Vol. 63, No. 1. (January 2007), pp. 0-0.

Inhibition of toll-like receptor and cytokine signaling--a unifying theme in ischemic tolerance.

K Karikó — 2007-10-20T19:00:32-00:00

J Cereb Blood Flow Metab, Vol. 24, No. 11. (November 2004), pp. 1288-1304.

Cerebral ischemia triggers acute inflammation, which exacerbates primary brain damage. Activation of the innate immune system is an important component of this inflammatory response. Inflammation occurs through the action of proinflammatory cytokines, such as TNF, IL-1 beta and IL-6, that alter blood flow and increase vascular permeability, thus leading to secondary ischemia and accumulation of immune cells in the brain. Production of these cytokines is initiated by signaling through Toll-like receptors (TLRs) that recognize host-derived molecules released from injured tissues and cells. Recently, great strides have been made in understanding the regulation of the innate immune system, particularly the signaling mechanisms of TLRs. Negative feedback inhibitors of TLRs and inflammatory cytokines have now been identified and characterized. It is also evident that lipid rafts exist in membranes and play a role in receptor-mediated inflammatory signaling events. In the present review, using this newly available large body of knowledge, we take a fresh look at studies of ischemic tolerance. Based on this analysis, we recognize a striking similarity between ischemic tolerance and endotoxin tolerance, an immune suppressive state characterized by hyporesponsiveness to lipopolysaccharide (LPS). In view of this analogy, and considering recent discoveries related to molecular mechanisms of endotoxin tolerance, we postulate that inhibition of TLR and proinflammatory cytokine signaling contributes critically to ischemic tolerance in the brain and other organs. Ischemic tolerance is a protective mechanism induced by a variety of preconditioning stimuli. Tolerance can be established with two temporal profiles: (i) a rapid form in which the trigger induces tolerance to ischemia within minutes and (ii) a delayed form in which development of protection takes several hours or days and requires de-novo protein synthesis. The rapid form of tolerance is achieved by direct interference with membrane fluidity, causing disruption of lipid rafts leading to inhibition of TLR/cytokine signaling pathways. In the delayed form of tolerance, the preconditioning stimulus first triggers the TLR/cytokine inflammatory pathways, leading not only to inflammation but also to simultaneous upregulation of feedback inhibitors of inflammation. These inhibitors, which include signaling inhibitors, decoy receptors, and anti-inflammatory cytokines, reduce the inflammatory response to a subsequent episode of ischemia. This novel interpretation of the molecular mechanism of ischemic tolerance highlights new avenues for future investigation into the prevention and treatment of stroke and related diseases.

Chemokines in ischemia and reperfusion.

NG Frangogiannis — 2007-10-20T18:55:49-00:00

Thromb Haemost, Vol. 97, No. 5. (May 2007), pp. 738-747.

Chemokine signaling plays an important role in the postischemic inflammatory response. Overlapping pathways involving reactive oxygen intermediates, Toll-like receptor (TLR) activation, the complement cascade and the nuclear factor (NF)-kappaB system induce both CXC and CC chemokines in ischemic tissues. Reperfusion accentuates chemokine expression promoting an intense inflammatory reaction. ELR-containing CXC chemokines regulate neutrophil infiltration in the ischemic area, whereas CXCR3 ligands may mediate recruitment of Th1 cells. CC chemokines, on the other hand, induce mononuclear cell infiltration and macrophage activation. Evidence suggests that chemokine signaling mediates actions beyond leukocyte chemotaxis and activation, regulating angiogenesis and fibrous tissue deposition. Effective repair of ischemic tissue is dependent on a well-orchestrated cellular response and on timely induction and suppression of chemokines in a locally restricted manner. This manuscript reviews the evidence suggesting a role for chemokine-mediated effects in ischemia/reperfusion and discusses the potential significance of these interactions in injury and repair of ischemic tissues.

Contextual cueing of visual attention

Marvin Chun — 2005-10-04T02:00:28-00:00

Trends in Cognitive Sciences, Vol. 4, No. 5. (1 May 2000), pp. 170-178.

Visual context information constrains what to expect and where to look, facilitating search for and recognition of objects embedded in complex displays. This article reviews a new paradigm called contextual cueing, which presents well-defined, novel visual contexts and aims to understand how contextual information is learned and how it guides the deployment of visual attention. In addition, the contextual cueing task is well suited to the study of the neural substrate of contextual learning. For example, amnesic patients with hippocampal damage are impaired in their learning of novel contextual information, even though learning in the contextual cueing task does not appear to rely on conscious retrieval of contextual memory traces. We argue that contextual information is important because it embodies invariant properties of the visual environment such as stable spatial layout information as well as object covariation information. Sensitivity to these statistical regularities allows us to interact more effectively with the visual world.

Full fat, semi-skimmed or no milk today creative commons licences and English folk music

Jones — 2006-05-18T16:20:21-00:00

International Review of Law, Computers & Technology, Vol. 19, No. 3. (November 2005), pp. 259-275.

Energy-efficient communication protocol for wireless microsensor networks

WR Heinzelman — 2006-08-24T09:04:49-00:00

System Sciences, 2000. Proceedings of the 33rd Annual Hawaii International Conference on (2000), 10 pp. vol.2.

Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military applications. In this paper, we look at communication protocols, which can have significant impact on the overall energy dissipation of these networks. Based on our findings that the conventional protocols of direct transmission, minimum-transmission-energy, multi-hop routing, and static clustering may not be optimal for sensor networks, we propose LEACH (Low-Energy Adaptive Clustering Hierarchy), a clustering-based protocol that utilizes randomized rotation of local cluster based station (cluster-heads) to evenly distribute the energy load among the sensors in the network. LEACH uses localized coordination to enable scalability and robustness for dynamic networks, and incorporates data fusion into the routing protocol to reduce the amount of information that must be transmitted to the base station. Simulations show the LEACH can achieve as much as a factor of 8 reduction in energy dissipation compared with conventional outing protocols. In addition, LEACH is able to distribute energy dissipation evenly throughout the sensors, doubling the useful system lifetime for the networks we simulated.

GPS-free-free positioning system for wireless sensor networks

F Benbadis — 2008-04-14T09:37:46-00:00

Wireless and Optical Communications Networks, 2005. WOCN 2005. Second IFIP International Conference on (2005), pp. 541-545.

Positioning systems are important components of many communication architectures. The traditional global positioning system (GPS) is impractical in many situations, which makes the need for relative measurement-based approaches. Existing relative solutions lead to good results but generally require that nodes are embedded with specific capabilities. in this paper, we propose GPS-free-free, a simple positioning system based on distances in number of hops between nodes. GPS-free-free make very loose assumptions (only neighborhood discovery) and does not require the computation of complex algorithms. We show through simulations that GPS-free-free leads to good placement results at very low signaling over-head.

Calculating with concepts: a technique for the development of business process support

R Dijkman — 2006-09-30T15:01:16-00:00

(2001)

This paper introduces the Calculating with Concepts (CC) technique, which has been developed to improve the precision of UML class diagrams and allows the formal reasoning based on these diagrams. This paper aims at showing the industrial benefits of using such a formal and rigorous approach to reason about business processes and software applications in the early phases of the software development process. The paper discusses how the CC technique can be used in the specification of business...

Accurate and Explicit Differentiation of Wireless and Congestion Losses

Vijay Arya — 2007-06-06T10:47:21-00:00

(2003)

In recent years mobile computing has experienced an explosive growth, mainly due to the integration of wireless networks with the wired Internet. To deploy bandwidthgreedy multimedia applications on such heterogeneous environments, efficient congestion control algorithms are required. When congestion control protocols such as TFRC are used to transmit multimedia flows, they need to differentiate between congestion losses and wireless losses to behave correctly and efficiently. Currently...

Implicit hop-by-hop congestion control in wireless multihop networks

Bjorn Scheuermann — 2007-04-27T08:24:07-00:00

Ad Hoc Networks, Vol. In Press, Corrected Proof

It has been shown that TCP and TCP-like congestion control are highly problematic in wireless multihop networks. In this paper we present a novel hop-by-hop congestion control protocol that has been tailored to the specific properties of the shared medium. In the proposed scheme, backpressure towards the source node is established implicitly, by passively observing the medium. A lightweight error detection and correction mechanism guarantees a fast reaction to changing medium conditions and low overhead. Our approach is equally applicable to TCP- and UDP-like data streams. We demonstrate the performance of our approach by an in-depth simulation study. These findings are underlined by testbed results obtained using an implementation of our protocol on real hardware.

Smooth and efficient real-time video transport in the presence of wireless errors

Guang Yang — 2007-06-06T11:16:49-00:00

ACM Trans. Multimedia Comput. Commun. Appl., Vol. 2, No. 2. (May 2006), pp. 109-126.

End-to-end differentiation of congestion and wireless Losses

S Cen — 2007-06-06T10:36:30-00:00

(2002)

In this paper, we explore end-to-end loss differentiation algorithms (LDAs) for use with congestion-sensitive video transport protocols for networks with either backbone or last-hop wireless links. As our basic video transport protocol, we use UDP in conjunction with a congestion control mechanism extended with an LDA. For congestion control, we use the TCP-Friendly Rate Control (TFRC) algorithm. We extend TFRC to use an LDA when a connection uses at least one wireless link in the path between...

Packet-pair flow control

Srinivasan Keshav — 2007-07-30T23:15:30-00:00

(1994)

This paper presents the packet-pair rate-based feedback flow control scheme. This scheme is designed for networks where individual connections do not reserve bandwidth and for the available bitrate (best-effort) component of integrated networks. We assume a round-robin-like queue service discipline in the output queues of the network's switches, and propose a linear stochastic model for a single conversation in a network of such switches. These model motivates the Packet-Pair rate probing...

LDA+: A TCP-Friendly Adaptation Scheme for Multimedia Communication

Dorgham Sisalem — 2007-03-13T21:52:30-00:00

(2000), pp. 1619-1622.

In this paper, we present an end-to-end adaptation scheme, called the enhanced loss-delay based adaptation algorithm (LDA+), for regulating the transmission behavior of multimedia senders in accordance with the network congestion state. LDA+ uses the real-time transport protocol (RTP) for collecting loss and delay statistics which are then used for adjusting the transmission behavior of the senders in a manner similar to TCP connections suffering from similar losses and delays. Performance...

A Control-Theoretic Approach to Flow Control

S Keshav — 2006-03-20T13:13:38-00:00

Proceedings of the conference on Communications architecture & protocols (1993), pp. 3-15.

This paper presents a control-theoretic approach to reactive flow control in networks that do not reserve bandwidth. We assume a round-robin-like queue service discipline in the output queues of the network's switches, and propose deterministic and stochastic models for a single conversation in a network of such switches. These models motivate the Packet-Pair rate probing technique, and a provably stable rate-based flow control scheme. A Kalman state estimator is derived from discrete-time...

Simulation of condylar growth in the cat with pulsating electromagnetic currents.

DW Haas — 2007-05-08T13:52:15-00:00

Am J Orthod Dentofacial Orthop, Vol. 108, No. 6. (December 1995), pp. 599-606.

Orthodontists have been, and are, interested in influencing facial growth, specifically, mandibular growth. The purpose of this investigation is to enhance condylar growth by means of electric stimulation. Eight growing cats were bilaterally condylotomized and unilaterally at random received electric stimulation. Before the condylotomy bonemarkers were implanted in the zygomatic process and above the condylotomy site. The condylotomy effectively separated the head of the condyle from the body of the mandible, thus unloading the head. After 5 weeks, implant separation indicated increased condylar growth on the treated side of all eight cats. Histologically, the treated condyles of six cats were different from the controls in that the hypertrophic zone was irregular and vascularization increased. The treated condyle showed significantly more bonemarker separation than the control condyle. On average, the treated condyle showed 1.24 mm more separation than the control (p = 0.001 by the paired sample t test).

Avian influenza virus and free-ranging wild birds.

LA Dierauf — 2006-10-31T17:15:50-00:00

J Am Vet Med Assoc, Vol. 228, No. 12. (15 June 2006), pp. 1877-1882.

Influenza pandemic periodicity, virus recycling, and the art of risk assessment.

WR Dowdle — 2006-10-31T17:13:02-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 34-39.

Influenza pandemic risk assessment is an uncertain art. The theory that influenza A virus pandemics occur every 10 to 11 years and seroarcheologic evidence of virus recycling set the stage in early 1976 for risk assessment and risk management of the Fort Dix, New Jersey, swine influenza outbreak. Additional data and passage of time proved the theory untenable. Much has been learned about influenza A virus and its natural history since 1976, but the exact conditions that lead to the emergence of a pandemic strain are still unknown. Current avian influenza events parallel those of swine influenza in 1976 but on a larger and more complex scale. Pre- and post-pandemic risk assessment and risk management are continuous but separate public health functions.

Avian influenza: preparing for a pandemic.

G Juckett — 2006-10-31T17:11:56-00:00

Am Fam Physician, Vol. 74, No. 5. (1 September 2006), pp. 783-790.

Avian influenza A (H5N1) first emerged as a global public health threat in 1997 when it caused a major human outbreak in Hong Kong. Endemic in waterfowl and highly virulent in poultry, H5N1 is capable of incidentally infecting humans and other mammals. Although H5N1 is not yet capable of efficient human-to-human transmission, the protean nature of its genome could transform it into the source of the next human influenza pandemic. In the spring of 2006, migrating birds spread the virus from Asia to Europe and Africa. Preparing for a new influenza pandemic involves increasing global influenza surveillance and developing practical strategies for containing outbreaks at the source. Prompt case recognition, isolation, and treatment will be crucial for disease control. Pharmacologic interventions will focus on streamlining the production of vaccine, extending vaccine supplies, stockpiling antiviral drugs such as oseltamivir, and distributing these agents in a timely manner to persons who have the most need. Nonpharmacologic measures will include the use of masks, social distancing, quarantine, travel restrictions, and increasing the emergency capacity of health care systems.

Vaccines and antiviral drugs in pandemic preparedness.

AS Monto — 2006-10-31T17:11:09-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 55-60.

While measures such as closing schools and social distancing may slow the effects of pandemic influenza, only vaccines and antiviral drugs are clearly efficacious in preventing infection or treating illness. Unless the pandemic strain closely resembles one already recognized, vaccine will not be available early. However, studies can be conducted beforehand to address questions concerning vaccine dose, frequency of inoculation, and need for adjuvants. In contrast, antiviral drugs, particularly the neuraminidase inhibitors, will be effective for treatment and available if stockpiling takes place. Special questions need to be answered if a highly lethal virus, such as influenza A (H5N1), produces the pandemic. Both vaccines and antiviral drugs will be required for a coordinated strategy.

Global patterns of influenza a virus in wild birds.

B Olsen — 2006-10-31T17:02:21-00:00

Science, Vol. 312, No. 5772. (21 April 2006), pp. 384-388.

The outbreak of highly pathogenic avian influenza of the H5N1 subtype in Asia, which has subsequently spread to Russia, the Middle East, Europe, and Africa, has put increased focus on the role of wild birds in the persistence of influenza viruses. The ecology, epidemiology, genetics, and evolution of pathogens cannot be fully understood without taking into account the ecology of their hosts. Here, we review our current knowledge on global patterns of influenza virus infections in wild birds, discuss these patterns in the context of host ecology and in particular birds' behavior, and identify some important gaps in our current knowledge.

Avian flu to human influenza.

DB Lewis — 2006-10-31T17:01:11-00:00

Annu Rev Med, Vol. 57 (2006), pp. 139-154.

Influenza A viral infection causes substantial annual morbidity and mortality worldwide, particularly for infants, the elderly, and the immunocompromised. The virus mainly replicates in the respiratory tract and is spread by respiratory secretions. A growing concern is the recent identification of H5N1 strains of avian influenza A in Asia that were previously thought to infect only wild birds and poultry, but have now infected humans, cats, pigs, and other mammals, often with fatal results, in an ongoing outbreak. A human pandemic with H5N1 virus could potentially be catastrophic because most human populations have negligible antibody-mediated immunity to the H5 surface protein and this viral subtype is highly virulent. Whether an H5N1 influenza pandemic will occur is likely to hinge on whether the viral strains involved in the current outbreak acquire additional mutations that facilitate efficient human-to-human transfer of infection. Although there is no historical precedent for an H5N1 avian strain causing widespread human-to-human transmission, some type of influenza A pandemic is very likely in the near future. The possibility of an H5N1 influenza pandemic has highlighted the many current limitations of treatment with antiviral agents and of vaccine production and immunogenicity. Future vaccine strategies that may include more robust induction of T-cell responses, such as cytotoxic T lymphocytes, may provide better protection than is offered by current vaccines, which rely solely or mainly on antibody neutralization of infection.

Cytotoxic therapy for severe avian influenza A (H5N1) infection.

JI Henter — 2006-10-31T17:00:26-00:00

Lancet, Vol. 367, No. 9513. (11 March 2006), pp. 870-873.

The mortality rate in documented avian influenza A virus subtype H5N1 infection is still high, which is currently reported by WHO at about 50%. Post-mortem analyses in affected patients have revealed haemophagocytosis similar to that found in patients with haemophagocytic lymphohistiocytosis (HLH); such haemophagocytosis could be a very prominent post-mortem feature in H5N1 infection. There are also clinical similarities between H5N1 infection and HLH, such as massive hypercytokinaemia, cytopenia, and acute encephalitis. Importantly, patients with another severe viral infection that may be complicated by secondary HLH, severe Epstein-Barr-virus-associated HLH, have significantly better survival if specific HLH therapy (including the cytotoxic and pro-apoptotic drug etoposide) is initiated early, with survival reported to rise from about 50% to 90%. With this notable improvement in survival, specific HLH treatment, including cytotoxic therapy, could be considered in patients with severe avian influenza A infection complicated by secondary HLH.

Influenza type A in humans, mammals and birds: determinants of virus virulence, host-range and interspecies transmission.

SJ Baigent — 2006-10-01T08:20:12-00:00

Bioessays, Vol. 25, No. 7. (July 2003), pp. 657-671.

The virulence of a virus is determined by its ability to adversely affect the host cell, host organism or population of host organisms. Influenza A viruses have been responsible for four pandemics of severe human respiratory disease this century. Avian species harbour a large reservoir of influenza virus strains, which can contribute genes to potential new pandemic human strains. The fundamental importance of understanding the role of each of these genes in determining virulence in birds and humans was dramatically emphasised by the recent direct transmission of avian influenza A viruses to humans, causing fatal infection but not community spread. An understanding of the factors involved in transmission between avian and mammalian species should assist in the development of better surveillance strategies for early recognition of influenza A virus strains having human pandemic potential, and possibly in the design of anti-viral strategies.

Avian influenza A (H5N1) infection in humans.

JH Beigel — 2006-03-14T17:23:54-00:00

N Engl J Med, Vol. 353, No. 13. (29 September 2005), pp. 1374-1385.

Avian influenza virus infections in humans.

SS Wong — 2006-10-01T07:52:50-00:00

Chest, Vol. 129, No. 1. (January 2006), pp. 156-168.

Seroepidemiologic and virologic studies since 1889 suggested that human influenza pandemics were caused by H1, H2, and H3 subtypes of influenza A viruses. If not for the 1997 avian A/H5N1 outbreak in Hong Kong of China, subtype H2 is the likely candidate for the next pandemic. However, unlike previous poultry outbreaks of highly pathogenic avian influenza due to H5 that were controlled by depopulation with or without vaccination, the presently circulating A/H5N1 genotype Z virus has since been spreading from Southern China to other parts of the world. Migratory birds and, less likely, bird trafficking are believed to be globalizing the avian influenza A/H5N1 epidemic in poultry. More than 200 human cases of avian influenza virus infection due to A/H5, A/H7, and A/H9 subtypes mainly as a result of poultry-to-human transmission have been reported with a > 50% case fatality rate for A/H5N1 infections. A mutant or reassortant virus capable of efficient human-to-human transmission could trigger another influenza pandemic. The recent isolation of this virus in extrapulmonary sites of human diseases suggests that the high fatality of this infection may be more than just the result of a cytokine storm triggered by the pulmonary disease. The emergence of resistance to adamantanes (amantadine and rimantadine) and recently oseltamivir while H5N1 vaccines are still at the developmental stage of phase I clinical trial are causes for grave concern. Moreover, the to-be pandemic strain may have little cross immunogenicity to the presently tested vaccine strain. The relative importance and usefulness of airborne, droplet, or contact precautions in infection control are still uncertain. Laboratory-acquired avian influenza H7N7 has been reported, and the laboratory strains of human influenza H2N2 could also be the cause of another pandemic. The control of this impending disaster requires more research in addition to national and international preparedness at various levels. The epidemiology, virology, clinical features, laboratory diagnosis, management, and hospital infection control measures are reviewed from a clinical perspective.

Avian influenza: an omnipresent pandemic threat.

DR Perez — 2006-03-14T17:04:44-00:00

Pediatr Infect Dis J, Vol. 24, No. 11 Suppl. (November 2005)

BACKGROUND: Humans have faced 3 major influenza pandemics in the 20th century. In recent years, it has become evident that domestic poultry play an important role in the generation of novel influenza strains with the capacity to cross the species barrier and infect and kill humans at an alarming rate. There is particular concern that avian influenza viruses of the H5N1 subtype could cause a pandemic. METHODS: A better understanding of the genetic factors that lead to interspecies transmission is essential to prevent the emergence of influenza pandemics. In addition, the stockpiling of antiviral drugs and development of vaccines against potentially pandemic viruses must be considered under the umbrella of pandemic plans. RESULTS: The world is ill-prepared to face an influenza pandemic. Only a handful of countries have developed influenza pandemic plans, and even fewer are developing vaccines or stockpiling antiinfluenza drugs to ameliorate the impact of a potential pandemic. Currently the major undertaking in several at risk nations is to implement effective control measures to stop the spread of the virus at its source, that is, avian species. These measures include the culling of domestic poultry to contain the virus, a practice that could eventually bring these countries to a financial and social breaking point. CONCLUSIONS: Avian influenza disease is preventable in humans and birds with the concerted effort of governments and poultry producers, large and small, to improve biosecurity and education programs. Pandemic plans can reduce the impact of the pandemic; however, preventing avian influenza in poultry can avert a pandemic altogether.

Vaccines in the pipeline.

MA Jackson — 2006-10-31T16:57:30-00:00

Pediatr Emerg Care, Vol. 21, No. 11. (November 2005)

Infectious Disease: Can We Avert a Lethal Flu Pandemic?

Robert May — 2005-11-22T21:20:07-00:00

Current Biology, Vol. 15, No. 22. (22 November 2005), pp. R922-R924.

If avian flu becomes directly transmissible among humans, could we prevent a pandemic by using prophylactic antivirals? Possibly, if the virus is not too transmissible, and we react fast and efficiently.

Public health risk from avian influenza viruses.

ML Perdue — 2006-10-31T16:57:14-00:00

Avian Dis, Vol. 49, No. 3. (September 2005), pp. 317-327.

Since 1997, avian influenza (AI) virus infections in poultry have taken on new significance, with increasing numbers of cases involving bird-to-human transmission and the resulting production of clinically severe and fatal human infections. Such human infections have been sporadic and are caused by H7N7 and H5N1 high-pathogenicity (HP) and H9N2 low-pathogenicity (LP) AI viruses in Europe and Asia. These infections have raised the level of concern by human health agencies for the potential reassortment of influenza virus genes and generation of the next human pandemic influenza A virus. The presence of endemic infections by H5N1 HPAI viruses in poultry in several Asian countries indicates that these viruses will continue to contaminate the environment and be an exposure risk with human transmission and infection. Furthermore, the reports of mammalian infections with H5N1 AI viruses and, in particular, mammal-to-mammal transmission in humans and tigers are unprecedented. However, the subsequent risk for generating a pandemic human strain is unknown. More international funding from both human and animal health agencies for diagnosis or detection and control of AI in Asia is needed. Additional funding for research is needed to understand why and how these AI viruses infect humans and what pandemic risks they pose.

The first confirmed human case of avian influenza A (H5N1) in Mainland China.

H Yu — 2006-10-01T07:38:10-00:00

Lancet, Vol. 367, No. 9504. (7 January 2006)

Avian influenza A (H5N1).

MD de Jong — 2006-10-01T07:31:38-00:00

J Clin Virol, Vol. 35, No. 1. (January 2006), pp. 2-13.

Since their reemergence in 2003, highly pathogenic avian influenza A (H5N1) viruses have reached endemic levels among poultry in several southeast Asian countries and have caused a still increasing number of more than 100 reported human infections with high mortality. These developments have ignited global fears of an imminent influenza pandemic. The current knowledge of the virology, clinical spectrum, diagnosis and treatment of human influenza H5N1 virus infections is reviewed herein.

H5N1 outbreaks and enzootic influenza.

RG Webster — 2006-10-31T16:54:43-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 3-8.

Ongoing outbreaks of H5N1 avian influenza in migratory waterfowl, domestic poultry, and humans in Asia during the summer of 2005 present a continuing, protean pandemic threat. We review the zoonotic source of highly pathogenic H5N1 viruses and their genesis from their natural reservoirs. The acquisition of novel traits, including lethality to waterfowl, ferrets, felids, and humans, indicates an expanding host range. The natural selection of nonpathogenic viruses from heterogeneous subpopulations co-circulating in ducks contributes to the spread of H5N1 in Asia. Transmission of highly pathogenic H5N1 from domestic poultry back to migratory waterfowl in western China has increased the geographic spread. The spread of H5N1 and its likely reintroduction to domestic poultry increase the need for good agricultural vaccines. In fact, the root cause of the continuing H5N1 pandemic threat may be the way the pathogenicity of H5N1 viruses is masked by co-circulating influenza viruses or bad agricultural vaccines.

Highly pathogenic avian influenza H5N1, Thailand, 2004.

T Tiensin — 2006-10-31T16:48:09-00:00

Emerg Infect Dis, Vol. 11, No. 11. (November 2005), pp. 1664-1672.

In January 2004, highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first confirmed in poultry and humans in Thailand. Control measures, e.g., culling poultry flocks, restricting poultry movement, and improving hygiene, were implemented. Poultry populations in 1,417 villages in 60 of 76 provinces were affected in 2004. A total of 83% of infected flocks confirmed by laboratories were backyard chickens (56%) or ducks (27%). Outbreaks were concentrated in the Central, the southern part of the Northern, and Eastern Regions of Thailand, which are wetlands, water reservoirs, and dense poultry areas. More than 62 million birds were either killed by HPAI viruses or culled. H5N1 virus from poultry caused 17 human cases and 12 deaths in Thailand; a number of domestic cats, captive tigers, and leopards also died of the H5N1 virus. In 2005, the epidemic is ongoing in Thailand.

Pandemic influenza threat and preparedness.

AS Fauci — 2006-10-31T16:45:54-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 73-77.

The threat of a human influenza pandemic has greatly increased over the past several years with the emergence of highly virulent avian influenza viruses, notably H5N1 viruses, which have infected humans in several Asian and European countries. Previous influenza pandemics have arrived with little or no warning, but the current widespread circulation of H5N1 viruses among avian populations and their potential for increased transmission to humans and other mammalian species may afford us an unprecedented opportunity to prepare for the next pandemic threat. The US Department of Health and Human Services is coordinating a national strategy to respond to an influenza pandemic that involves multiple agencies, including the Centers for Disease Control and Prevention, the Food and Drug Administration, and the National Institutes of Health (NIH). Within NIH, the National Institute of Allergy and Infectious Diseases (NIAID) conducts basic and clinical research to develop new vaccine technologies and antiviral drugs against influenza viruses. We describe recent research progress in preparing for pandemic influenza.

Vaccines for pandemic influenza.

CJ Luke — 2006-10-31T16:45:39-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 66-72.

Recent outbreaks of highly pathogenic avian influenza in Asia and associated human infections have led to a heightened level of awareness and preparation for a possible influenza pandemic. Vaccination is the best option by which spread of a pandemic virus could be prevented and severity of disease reduced. Production of live attenuated and inactivated vaccine seed viruses against avian influenza viruses, which have the potential to cause pandemics, and their testing in preclinical studies and clinical trials will establish the principles and ensure manufacturing experience that will be critical in the event of the emergence of such a virus into the human population. Studies of such vaccines will also add to our understanding of the biology of avian influenza viruses and their behavior in mammalian hosts.

Making better influenza virus vaccines?

P Palese — 2006-10-31T16:45:23-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 61-65.

Killed and live influenza virus vaccines are effective in preventing and curbing the spread of disease, but new technologies such as reverse genetics could be used to improve them and to shorten the lengthy process of preparing vaccine seed viruses. By taking advantage of these new technologies, we could develop live vaccines that would be safe, cross-protective against variant strains, and require less virus per dose than conventional vaccines. Furthermore, pandemic vaccines against highly virulent strains such as the H5N1 virus can only be generated by reverse genetics techniques. Other technologic breakthroughs should result in effective adjuvants for use with killed and live vaccines, increasing the number of available doses. Finally, universal influenza virus vaccines seem to be within reach. These new strategies will be successful if they are supported by regulatory agencies and if a robust market for influenza virus vaccines against inter-pandemic and pandemic threats is made and sustained.

Cell-mediated protection in influenza infection.

PG Thomas — 2006-10-31T16:45:04-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 48-54.

Current vaccine strategies against influenza focus on generating robust antibody responses. Because of the high degree of antigenic drift among circulating influenza strains over the course of a year, vaccine strains must be reformulated specifically for each influenza season. The time delay from isolating the pandemic strain to large-scale vaccine production would be detrimental in a pandemic situation. A vaccine approach based on cell-mediated immunity that avoids some of these drawbacks is discussed here. Specifically, cell-mediated responses typically focus on peptides from internal influenza proteins, which are far less susceptible to antigenic variation. We review the literature on the role of CD4+ and CD8+ T cell-mediated immunity in influenza infection and the available data on the role of these responses in protection from highly pathogenic influenza infection. We discuss the advantages of developing a vaccine based on cell-mediated immune responses toward highly pathogenic influenza virus and potential problems arising from immune pressure.

Antiviral response in pandemic influenza viruses.

A García-Sastre — 2006-10-31T16:44:48-00:00

Emerg Infect Dis, Vol. 12, No. 1. (January 2006), pp. 44-47.

The outcome of viral infections depends on a complex set of interactions between the viruses and their hosts. Particularly, viral infection triggers specific signaling programs within the infected cells that results in substantial changes in host gene expression. While some of these changes might be beneficial for viral replication, others represent the induction of a host antiviral response. In this respect, viruses have evolved genes that counteract this initial innate antiviral response. These viral-host interactions shape the subsequent phases of the disease and influence the adaptive immune response. In influenza viruses, the nonstructural protein 1 inhibits the interferon-mediated antiviral response. The regulatory activities of this viral protein play a major role in the pathogenicity of influenza virus and appear partially responsible for the ability of influenza viruses to infect multiple animal species, which likely contributes to the generation of new pandemic viruses in humans.

Host range restriction and pathogenicity in the context of influenza pandemic.

G Neumann — 2006-10-31T16:42:56-00:00

Emerg Infect Dis, Vol. 12, No. 6. (June 2006), pp. 881-886.

Influenza A viruses cause pandemics at random intervals. Pandemics are caused by viruses that contain a hemagglutinin (HA) surface glycoprotein to which human populations are immunologically naive. Such an HA can be introduced into the human population through reassortment between human and avian virus strains or through the direct transfer of an avian influenza virus to humans. The factors that determine the interspecies transmission and pathogenicity of influenza viruses are still poorly understood; however, the HA protein plays an important role in overcoming the interspecies barrier and in virulence in avian influenza viruses. Recently, the RNA polymerase (PB2) protein has also been recognized as a critical factor in host range restriction, while the nonstructural (NS1) protein affects the initial host immune responses. We summarize current knowledge of viral factors that determine host range restriction and pathogenicity of influenza A viruses.

The European Union and Global Climate Change: A Review of Five National Programmes - John Gummer and Robert Moreland, Pew Center on Global Climate change, June 2000. Review by Micheal Grubb

M Grubb — 2006-01-20T15:11:31-00:00

Climate Policy, Vol. 1, No. 3. (September 2001), pp. 426-429.

The evolution of body mass and relative brain size in fossil hominids

J Kappelman — 2006-11-09T20:37:39-00:00

(1996), pp. 243-276.

The observation that absolute brain size increased over the past 2 million years is one of the few uncontested facts of hominid evolution. There is, however, less agreement about how the size of the brain evolved relative to that of the body. Relative brain size has proven to be difficult to quantify because fossil hominid crania that offer the endocranial measurements, and postcrania that generally provide the body-mass estimates, can only rarely be attributed to the same individual. If it could be established that some aspect of the cranium is strongly correlated with body mass, then relative brain size could be calculated for each fossil hominid cranium that has a measured endocranial volume. This paper investigates one such cranial feature, the area of the orbital aperture, and its correlation with body mass in a large sample of extant primates. The results demonstrate that orbital area is correlated with body mass at r =0?987. Predictions of body mass on the basis of orbital area measured for fossil hominids suggest that body mass in Homo increased through time, and that body mass sexual dimorphism was possibly somewhat greater for some fossil hominid species than it is in living humans. Combining these body mass estimates with measures of endocranial volume demonstrates increased relative brain size for both Australopithecus and archaic Homo , with the values for Australopithecus exceeding those of the living hominoids, and archaic Homo exceeding those of Australopithecus . The step-like differences among these taxa stand in contrast to the observation that there appears to have been no or only a negligible increase in relative brain size through the subsequent nearly 2 million years of evolution in the genus Homo . The most dramatic changes occur with the appearance of modern Homo sapiens at about 100,000 years ago and include a decrease in body mass and an increase in relative brain size that appears to have been driven by selection for smaller body mass.

Subjects, Subjectivity, and Subjectification in Call Center Work: The Doings of Doings

Donald Winiecki — 2007-08-23T12:20:29-00:00

Journal of Contemporary Ethnography, Vol. 36, No. 4. (1 August 2007), pp. 351-377.

In postindustrial society, paid labor is increasingly characterized as tertiary labor rather than primary or secondary labor and commonly mediated by computer and telecommunication technologies. However, there are few ethnographic studies on the production of the subject and subjectivity in postindustrial workplaces. This article reports a poststructurally informed ethnographic research in four telephone call centers, focusing on how technological and managerial practices are deployed and continuously oriented to in subjectification processes. The result, although "rational" and "real," is shown to be a construction of concerted compliance and secondary adjustments through strategic processes named shadowboxing with data. Implications for the study of subjectivity and subjectification are discussed. 10.1177/0891241606293141

How Can I Help You? Call Centres, Classification Work and Coordination

David Martin — 2007-07-26T13:30:35-00:00

Computer Supported Cooperative Work (CSCW), Vol. 16, No. 3. (June 2007), pp. 231-264.

As a comparatively novel but increasingly pervasive organizational arrangement, call centres have been a focus for much recent research. This paper identifies lessons for organizational and technological design through an examination of call centres and `classification work' - explicating what Star [1992, Systems/Practice vol. 5, pp. 395-410] terms the `open black box'. Classification is a central means by which organizations standardize procedure, assess productivity, develop services and re-organize their business. Nevertheless, as Bowker and Star [1999, Sorting Things Out: Classification and Its Consequences. Cambridge MA: MIT Press] have pointed out, we know relatively little about the work that goes into making classification schema what they are. We will suggest that a focus on classification `work' in this context is a useful exemplar of the need for some kind of `meta-analysis' in ethnographic work also. If standardization is a major ambition for organizations under late capitalism, then comparison might be seen as a related but as-yet unrealized one for ethnographers. In this paper, we attempt an initial cut at a comparative approach, focusing on classification because it seemed to be the primary issue that emerged when we compared studies. Moreover, if technology is the principal means through which procedure and practice is implemented and if, as we believe, classifications are becoming ever more explicitly embedded within it (for instance with the development of so-called `semantic web' and associated approaches to ontology-based design), then there is clearly a case for identifying some themes which might underpin classification work in a given domain.

Gaining confidence in high-throughput protein interaction networks.

JS Bader — 2005-06-14T02:53:11-00:00

Nat Biotechnol, Vol. 22, No. 1. (January 2004), pp. 78-85.

Although genome-scale technologies have benefited from statistical measures of data quality, extracting biologically relevant pathways from high-throughput proteomics data remains a challenge. Here we develop a quantitative method for evaluating proteomics data. We present a logistic regression approach that uses statistical and topological descriptors to predict the biological relevance of protein-protein interactions obtained from high-throughput screens for yeast. Other sources of information, including mRNA expression, genetic interactions and database annotations, are subsequently used to validate the model predictions without bias or cross-pollution. Novel topological statistics show hierarchical organization of the network of high-confidence interactions: protein complex interactions extend one to two links, and genetic interactions represent an even finer scale of organization. Knowledge of the maximum number of links that indicates a significant correlation between protein pairs (correlation distance) enables the integrated analysis of proteomics data with data from genetics and gene expression. The type of analysis presented will be essential for analyzing the growing amount of genomic and proteomics data in model organisms and humans.

Enhancing Community Colleges Through Professional Development : New Directions for Community Colleges (J-B CC Single Issue Community Colleges)

Cc — 2006-01-17T20:34:15-00:00

(10 May 2003)

Community college professional development programs can be dynamic forces in helping community colleges address significant issues, create solutions for change, and create opportunities for renewal. This issue examines the challenges and rewards of creating an effective professional development program. Editor Gordon E. Watts, professor of higher education at the University of Arkansas at Little Rock, brings together the research and findings of scholars in the fields of higher education and economics as well as the perspectives of professionals in staff and organizational development at community colleges and community based organizations. Beginning with an overview of the ongoing need for professional development in the community college, its current status, its struggles to become institutionalized as a function in the community college, the issue offers a much needed perspective on professional development's expanding role and that challenges that it continues to face. Chapter authors illustrate how their institutions have addressed issues through professional development, created institutional change, developed new delivery systems for professional development, reached beyond development just for faculty, and found new uses for traditional development activities. Faculty development programs examined include orientation programs for new faculty members and programs that address the specific needs of part-time faculty. An analysis of an innovative online faculty development delivery system for both new and part-time faculty is presented along with positive outcomes of the program's implementation at two separate institutions. Another chapter explores the emergence of teaching and learning centers as catalysts for effective faculty development and institutional change. Addressing campus development needs beyond faculty, other chapters examine staff development programs that include administration and classified staff as well as comprehensive programs that address professional development across the campus. The highly successful "great teacher" model for faculty development is revisited with descriptions of how the Great Teachers Seminars model can be taken a step further and successfully applied to classified, administration, and organizational development initiatives. As senior staff and faculty move toward retirement in greater numbers, potential shortages in leadership create the need for effective professional development at leadership levels. Evolution of the Presidents Academy, an innovative professional development program for newly appointed presidents, is examined in detail. Also explored is the need and importance of a renewed focus on leadership development overall and how leadership development strategies can be strengthened to ensure a continuous supply of well-trained community college leaders.

Discovery of inhibitors of protein-protein interactions from combinatorial libraries.

MJ Vicent — 2008-01-07T11:28:48-00:00

Curr Top Med Chem, Vol. 7, No. 1. (2007), pp. 83-95.

Protein-protein interactions play a central role within numerous processes in the cell. The relevance of the processes in which this type of interactions are implicated make them responsible for many pathological situations. In the last decade protein-protein interfaces have shown their potential as new drug targets, and combinatorial chemistry has been defined as a useful tool in this line. This review gives a global vision of the actual situation of combinatorial chemistry, highlighting its applicability to high-throughput drug discovery and giving some crucial examples of its contribution to find modulators of protein-protein interactions.

Energy Technology Handbook

DM Considine — 2007-02-28T16:30:33-00:00

(01 June 1977)

Analysis of Cycle Configurations for the Modernization of Combined Heat and Power Plant by Fitting a Gas Turbine System

Tadeusz Chmielniak — 2007-03-07T18:33:02-00:00

Journal of Engineering for Gas Turbines and Power, Vol. 126, No. 4. (2004), pp. 816-822.

The application of a gas turbine generally allows to increase the number of possible configurations of cogenerated heat and electrical power systems, which became a significant substitute for classic, coal-fired power plants. They are characterized by better thermodynamical, economical, ecological, and operating indexes. Gas turbine units are also the best option for the modernization of existing power plants. This paper discusses the effectiveness of various technological configurations with gas turbines, which are to be applied during modernization projects of already existing conventional combined heat and power plants. In the analysis enthalpy and entropy methods were applied. Algorithms of the entropy method allow to determine the entropy generation in each section of a combined heat and power (CHP) plant. Several criteria were taken into consideration while analyzing the effectiveness of technological cycle configurations with gas turbines. These include the energy effectiveness, the efficiency of the HRSG and the steam cycle, the efficiency of the whole thermal electric power station, the exergetic efficiency of the HRSG and the steam cycle, and the fuel efficiency index. It was assumed that gas turbines operate under their nominal conditions. The composite curves were also taken into consideration while choosing the type of the turbine. The modernization project tends not to eliminate those existing power plant sections (machines and equipment), which are able to operate further. The project suggests that those units should remain in the system, which satisfy the applied durability criterion. The last phase of the optimization project focuses on the sensibility verification of several steam-gas CHP plant parameters and their influence on the whole system. ©2004 ASME