bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a Novel Liquid Desiccant Dehumidifier/Regenerator System
Authors: So’Brien G. C. , Satcunanathan S.
Published: November 2009

A novel liquid desiccant dehumidifier/regenerator system is described in this paper. The system involves continuous dehumidification of air and simultaneous desiccant regeneration without the use of mechanical circulation. During initial tests, the measured COP was of the order of 0.3 even with regenerator temperatures as low as 50° C. Overall considerations indicated that for the purposes of solar air conditioning, this system has several important advantages over other methods.
Comparison of Thermoelectric and Vapor Cycle Technologies for Groundwater Heat Pump Application
Authors: Mei V. C. , Chen F. C. , Mathiprakasam B.
Published: November 2009

The performance of a groundwater thermoelectric (TE) heat pump system, based on today’s state-of-the-art TE materials, was calculated and compared with that of a conventional groundwater heat pump under the same water inlet temperature and flow rate. It was found that the TE system was competitive for cooling, particularly for groundwater temperatures below 18° C (64° F). The TE system performed poorly for heating mode operation. A cooling coefficient of performance (COP) of 6.4 could be realized by a properly designed TE system at a groundwater temperature of 13° C (55° F), compared with a COP of 4.35 for a conventional heat pump. For heating mode operation at the same water temperature, the TE system achieved a COP of 1.72, while the conventional heat pump performed at a COP of 3.72. Use of TE systems should be considered in areas where year-round cooling load dominates.
A Modified Flip-Chip LED Packaging Design With Enhanced Light Coupling Efficiency for Plastic Optical Fiber Networks
Authors: Wang Chuen-Ching , Yang Wen-Ran , Chen Jin-Jia , Shi Wei-Wen
Published: November 2009

The explosive growth in the use of the Internet and multimedia applications in both the home and the office has fueled the requirement for high-bandwidth communication systems capable of processing huge volumes of data in a prompt and reliable manner. Plastic optical fiber (POF) has emerged as an ideal solution for meeting this requirement and is now specified by many architects as a simple, one-cable solution for home and office data communication networks. This study presents a modified flip-chip light emitting diode (LED) package for use in short-distance, POF-based communication systems. In contrast to the planar surface of the traditional design, the proposed LED package has a curved boundary surface between the underfill and the air. This boundary surface functions as a virtual lens, which focuses the light emitted by the LED into the acceptance cone of the optical fiber such that the amount of light coupled into the fiber core is maximized. The proposed design yields an average coupling efficiency of around 49.6% over an LED-optical core misalignment range of 0.4–3 mm. Furthermore, the curved boundary surface reduces the distance between the emitting source and the ambient environment; therefore, it improves the thermal dispersion efficiency of the LED package.
Thermal and Structural Analysis of a Suspended Physics Package for a Chip-Scale Atomic Clock
Authors: Laws A. D. , Borwick R. , Stupar P. , DeNatale J. , Lee Y. C.
Published: November 2009

The power dissipation for chip-scale atomic clocks (CSAC) is one of the major design considerations. 12 mW of the 30 mW power budget is for temperature control of the vertical-cavity-surface-emitting laser (VCSEL) and the alkali-metal vapor cell. Each of these must be maintained at 70+/−0.1°C even over large ambient temperature variations of 0–50°C. Thus the physics package of a CSAC device, which contains the vapor cell, VCSEL, and optical components, must have a very high thermal resistance, greater than 5.83°C/m W, to operate in 0°C ambient temperatures while dissipating less than 12 mW of power for heating. To create such a high level of insulation, the physics package is enclosed in a gold coated vacuum package and is suspended on a specially designed structure made from Cirlex, a type of polyimide. The thermal performance of the suspended physics package has been evaluated by measuring the total thermal resistance from a mockup package with and without an enclosure. Without an enclosure, the thermal resistance was found to be 1.07°C/m W. With the enclosure, the resistance increases to 1.71°C/m W. These two cases were modeled using finite element analysis (FEA), the results of which were found to match well with experimental measurements. A FEA model of the real design of the enclosed and suspended physics package was then modeled and was found to have a thermal resistance of 6.28°C/m W, which meets the project requirements of greater than 5.83°C/m W. The structural performance of the physics package was measured by shock-testing, a physics package mockup and recording the response with a high-speed video camera. The shock tests were modeled using dynamic FEA and were found to match well with the displacement measurements. A FEA model of the final design, not the mockup, of the physics package was created and was used to predict that the physics package will survive a 1800 g shock of any duration in any direction without exceeding the Cirlex yield stress of 49 MPa. In addition, the package will survive a 10,000 g shock of any duration in any direction without exceeding the Cirlex tensile stress of 229 MPa.
Novel Design of Thermal-Via Configurations for Collector-Up HBTs
Authors: Lee Pei-Hsuan , Tseng Hsien-Cheng , Chou Jung-Hua
Published: November 2009

We devise a finite-element model to analyze the thermal performance of collector-up (C-up) heterojunction bipolar transistors (HBTs) with a thermal-via configuration. A demonstration on the GaInP/GaAs C-up HBT is presented in this Brief, and the novelty of this work is that both 2D and 3D temperature-distribution analyses are performed. The 2D results indicate that the original thermal-via configuration can be reduced by 29%. Furthermore, the results show that the maximum temperature within the collector calculated from 3D analysis is lower than that from the 2D analysis. Based on the 3D analysis, it is revealed that the reported configuration can be reduced by 32%. Therefore, the C-up HBT with a compact thermal-via should be helpful for miniaturization of heat-dissipation packaging configurations within HBT-based high-power amplifiers.
Simulation study on the influences of the bonding parameters on the warpage of chip-on-glass module with nonconductive film
Authors: Zhang Jianhua , Yuan Fang , Zhang Jinsong
Published: November 2009

Nonconductive film (NCF) interconnection technology is now being used for the ultrafine pitch interconnections in chip-on-glass (COG) packaging. In comparison to traditional anisotropic conductive film (ACF) technology, NCF can reach less than 10μm ultrafine pitch interconnection, while ACF just reaches the limit of 30μm. For NCF interconnection technology used in COG bonding, it needs a higher bonding pressure and temperature than those in ACF bonding, so the warpage is very important for the reliability of the package. In this paper, an exploring study investigated the effects of the structure design and bonding process on the warpage in a COG module. The warpage increased linearly with the increase in bonding head temperature and bonding force, but it decreased with the increase in substrate temperature, substrate thickness, and chip thickness. The large temperature difference between the substrate and chip produced a high thermal stress, and the large bonding force generated a high mechanical stress. The thermal and mechanical stresses were the reasons for warpage in a COG module. For the high reliability, the design and bonding process to the COG module with NCF should adopt a thick substrate, an appropriate bonding force, and a low temperature difference.
How Telomeres Solve the End-Protection Problem
Authors: de Lange Titia
Published: November 2009

The ends of eukaryotic chromosomes have the potential to be mistaken for damaged or broken DNA and must therefore be protected from cellular DNA damage response pathways. Otherwise, cells might permanently arrest in the cell cycle, and attempts to “repair” the chromosome ends would have devastating consequences for genome integrity. This end-protection problem is solved by protein-DNA complexes called telomeres. Studies of mammalian cells have recently uncovered the mechanism by which telomeres disguise the chromosome ends. Comparison to unicellular eukaryotes reveals key differences in the DNA damage response systems that inadvertently threaten chromosome ends. Telomeres appear to be tailored to these variations, explaining their variable structure and composition.
Mutations in Two Independent Pathways Are Sufficient to Create Hermaphroditic Nematodes
Authors: Baldi Chris , Cho Soochin , Ellis Ronald E.
Published: November 2009

Life Histories to Suit

Nematode worms can profoundly manipulate their life histories in several ways. For example,
Caenorhabditis elegans
has two genders: males and hermaphrodites. Some clues for the evolution of this peculiar mating system have been revealed by

Baldi
et al.

(p.
1002
), who turned females of a related species,
Caenorhabditis remanei
, into hermaphrodites by modifying a gene involved in making sperm and another gene required for activating the spermatids. In most animals, the germ line is fully established during adulthood and a reproductive period is determined, at least in part, by aging of the germ line and the viability of oocytes. The reproductive longevity of hermaphrodite
C. elegans
can be increased at least 15-fold by starvation.
Angelo and Van Gilst
(p.
954
, published online 27 August; see the Perspective by

Ogawa and Sommer

) found that in starved worms, the germline component of the reproductive system is actively killed, with the exception of a small set of preserved stem cells. When the worms are able to feed again, these cells regenerate into an entirely new and functional germ line. But this is not all.

Kim
et al.

(p.
994
, published online 1 October; see the Perspective by

Ogawa and Sommer

) show that subsets of the complex mixture of structurally related molecules in dauer pheromone act via distinct G protein–coupled receptors either to initiate longterm effects on development and physiology by modulating the neuroendocrine axis, or to trigger short-term acute effects on behavior by altering neuronal responses.
Observation of the Role of Subcritical Nuclei in Crystallization of a Glassy Solid
Authors: Lee Bong-Sub , Burr Geoffrey W. , Shelby Robert M. , Raoux Simone , Rettner Charles T. , Bogle Stephanie N. , Darmawikarta Kristof , Bishop Stephen G. , Abelson John R.
Published: November 2009

Catching Glassy Crystallization

The initial steps for crystallization are difficult to study in atomic materials because they occur on very small length- and time scales. Measurements can be made on surfaces, or by using colloids as analogs, but ideally one would like to observe the ordering phenomena in atomic solids in bulk.

Lee
et al.

(p.
980
; see the Perspective by

Gibson

) use fluctuation transmission electron microscopy to explore the role of nucleation in propagating crystallization and discovered that formation of subcritical nuclei strongly influences the crystallization process.
Photosynthesis in the Open Ocean
Authors: Zehr Jonathan P. , Kudela Raphael M.
Published: November 2009

A little-understood electron flow pathway helps cyanobacteria to adapt to high-light, low-nutrient ocean environments.
Viewing the Seeds of Crystallization
Authors: Gibson J. Murray
Published: November 2009

Electron microscopy is providing glimpses of the complex structural processes that precede crystal nucleation.
Strategies to Get Arrested
Authors: Ogawa Akira , Sommer Ralf J.
Published: November 2009

Two gene families in the worm control survival strategies in response to stressful environmental conditions.
Europe Reconsiders H1N1 Flu Shots for Children
Authors: Enserink Martin
Published: November 2009

As the H1N1 flu outbreak gathers speed and more vaccine becomes available, some European countries are now telling families that healthy children—or at least infants—are candidates for vaccination after all. The change of mind did not reassure a jittery public.
Dangerous Liaison
Authors: Khidr Lily
Published: November 2009

HIV-1 sticks to sperm and facilitates transmission of the virus to immune cells.
Multiantigen Print Immunoassay for Comparison of Diagnostic Antigens for
Taenia solium
Cysticercosis and Taeniasis
Authors: Handali Sukwan , Klarman Molly , Gaspard Amanda N. , Noh John , Lee Yeuk-Mui , Rodriguez Silvia , Gonzalez Armando E. , Garcia Hector H. , Gilman Robert H. , Tsang Victor C. W. , Wilkins Patricia P.
Published: November 2009

One of the best-characterized tests for the diagnosis of neurocysticercosis is the enzyme-linked immunoelectrotransfer blot assay, developed at the CDC, which uses lentil lectin-purified glycoproteins (LLGPs) extracted from
Taenia solium
cysticerci. The purification of the LLGP antigens has been difficult to standardize, and the polyacrylamide gel system used for the immunoblot assay is not easily transferable to other laboratories. In this study, we developed a multiantigen printing immunoassay (MAPIA) to compare the performance of multiple recombinant
Taenia solium
proteins with the potential for the detection of cysticercosis and taeniasis. We prepared MAPIA strips using six cysticercosis and two taeniasis diagnostic proteins and compared the performance of the proteins with sera collected from defined cysticercosis and taeniasis cases. Of the six cysticercosis antigens, rT24H performed well in detecting cases with two or more viable cysts in the brain (sensitivity and specificity, 97% and 99.4%, respectively); the use of a combination of cysticercosis antigens did not improve the sensitivity of the test and decreased the specificity. None of the antigens could differentiate the different clinical presentations of cysticercosis. Both of the taeniasis antigens (rES33 and rES38) had the same sensitivity of 99.4% and specificities of 93.9% and 94.5%, respectively. Some cross-reactivity against rES33 and rES38 was found, especially with sera from cases infected with
Schistosoma mansoni
. We conclude that MAPIA is a simple and effective tool that may be used to compare antibody responses to different cysticercosis and taeniasis antigens and, in this case, may be useful for the rapid detection of
T. solium
cases.
Clinical and Immunological Insights on Severe, Adverse Neurotropic and Viscerotropic Disease following 17D Yellow Fever Vaccination
Authors: Silva Maria Luiza , Espírito-Santo Luçandra Ramos , Martins Marina Angela , Silveira-Lemos Denise , Peruhype-Magalhães Vanessa , Caminha Ricardo Carvalho , de Andrade Maranhão-Filho Péricles , Auxiliadora-Martins Maria , de Menezes Martins Reinaldo , Galler Ricardo , da Silva Freire Marcos , Marcovistz Rugimar , Homma Akira , Teuwen Dirk E. , Elói-Santos Silvana Maria , Andrade Mariléia Chaves , Teixeira-Carvalho Andréa , Martins-Filho Olindo Assis
Published: November 2009

Yellow fever (YF) vaccines (17D-204 and 17DD) are well tolerated and cause very low rates of severe adverse events (YEL-SAE), such as serious allergic reactions, neurotropic adverse diseases (YEL-AND), and viscerotropic diseases (YEL-AVD). Viral and host factors have been postulated to explain the basis of YEL-SAE. However, the mechanisms underlying the occurrence of YEL-SAE remain unknown. The present report provides a detailed immunological analysis of a 23-year-old female patient. The patient developed a suspected case of severe YEL-AVD with encephalitis, as well as with pancreatitis and myositis, following receipt of a 17D-204 YF vaccination. The patient exhibited a decreased level of expression of Fc-γR in monocytes (CD16, CD32, and CD64), along with increased levels of NK T cells (an increased CD3
+
CD16
+/−
CD56
+/−
/CD3
+
ratio), activated T cells (CD4
+
and CD8
+
cells), and B lymphocytes. Enhanced levels of plasmatic cytokines (interleukin-6 [IL-6], IL-17, IL-4, IL-5, and IL-10) as well as an exacerbated
ex vivo
intracytoplasmic cytokine pattern, mainly observed within NK cells (gamma interferon positive [IFN-γ
+
], tumor necrosis factor alpha positive [TNF-α
+
], and IL-4 positive [IL-4
+
]), CD8
+
T cells (IL-4
+
and IL-5
+
), and B lymphocytes (TNF-α
+
, IL-4
+
, and IL-10
+
). The analysis of CD4
+
T cells revealed a complex profile that consisted of an increased frequency of IL-12
+
and IFN-γ
+
cells and a decreased percentage of TNF-α
+
, IL-4
+
, and IL-5
+
cells. Depressed cytokine synthesis was observed in monocytes (TNF-α
+
) following the provision of antigenic stimuli
in vitro
. These results support the hypothesis that a strong adaptive response and abnormalities in the innate immune system may be involved in the establishment of YEL-AND and YEL-AVD.
Kinetics of Antibody Persistence following Administration of a Combination Meningococcal Serogroup C and
Haemophilus influenzae
Type b Conjugate Vaccine in Healthy Infants in the United Kingdom Primed with a Monovalent Meningococcal Serogroup C Vaccine
Authors: Borrow Ray , Andrews Nick , Findlow Helen , Waight Pauline , Southern Joanna , Crowley-Luke Annette , Stapley Lorraine , England Anna , Findlow Jamie , Miller Elizabeth
Published: November 2009

The kinetics of antibody persistence following the administration of a combination meningococcal serogroup C and
Haemophilus influenzae
type b (Hib) conjugate vaccine (Menitorix) in the second year of life in children primed with two doses of one of three monovalent meningococcal serogroup C (MCC) vaccines was investigated. The study subjects were administered either Menitorix at 12 to 15 months of age, followed by the seven-valent pneumococcal conjugate vaccine (PCV7) and the measles, mumps, and rubella vaccine 4 to 6 weeks later, or all three vaccines concomitantly at 12 to 15 months of age. Blood samples were collected before and 1, 2, 12, and 24 months after the boosting. Sera were analyzed for meningococcal serogroup C serum bactericidal antibody (SBA) and IgG as well as Hib-polyribosylribitol phosphate (PRP)-specific IgG. The antibody persistence data from this study were compared to those of a prior study of Southern et al. (Clin. Vaccine Immunol. 14:1328-1333, 2007) in which children were given three primary doses of a vaccine containing both the MCC and the Hib vaccines but were boosted only with a Hib conjugate vaccine. The magnitude of the meningococcal SBA geometric mean titer was higher for those subjects primed with the MCC vaccine conjugated to tetanus toxoid (NeisVac-C) than for those primed with one of two MCC vaccines conjugated to CRM
197
(Menjugate or Meningitec) up to 1 year following boosting. Two years after boosting, the percentages of subjects with putatively protective SBA titers of ≥8 for children primed with NeisVac-C, Menjugate, and Meningitec were 43%, 22%, and 23%, respectively. Additional booster doses of the MCC vaccine may be required in the future to maintain good antibody levels; however, there is no immediate need for a booster during adolescence, as mathematical modeling has shown that persisting herd immunity is likely to control disease for a number of years.
HIV-Selectest Enzyme Immunoassay and Rapid Test: Ability To Detect Seroconversion following HIV-1 Infection
Authors: Khurana Surender , Norris Philip J. , Busch Michael P. , Haynes Barton F. , Park Susan , Sasono Pretty , Mlisana Koleka , Salim Abdool Karim , Hecht Frederick M. , Mulenga Joseph , Chomba Elwyn , Hunter Eric , Allen Susan , Nemo George , Rodriguez-Chavez Isaac R. , Margolick Joseph B. , Golding Hana
Published: November 2009

HIV-Selectest is a serodiagnostic enzyme immunoassay (EIA), containing p6 and gp41 peptides, designed to differentiate between vaccine-induced antibodies and true infections. A rapid test version of the HIV-Selectest was developed. Both assays detected HIV antibodies in men and women within 2 to 4 weeks of infection, with sensitivity similar to third-generation EIAs.
GC Content-Based Pan-Pox Universal PCR Assays for Poxvirus Detection
Authors: Li Yu , Meyer Hermann , Zhao Hui , Damon Inger K.
Published: November 2009

Chordopoxviruses of the subfamily
Chordopoxvirinae
, family
Poxviridae
, infect vertebrates and consist of at least eight genera with broad host ranges. For most chordopoxviruses, the number of viral genes and their relative order are highly conserved in the central region. The GC content of chordopoxvirus genomes, however, evolved into two distinct types: those with genome GC content of more than 60% and those with a content of less than 40% GC. Two standard PCR assays were developed to identify chordopoxviruses based on whether the target virus has a low or high GC content. In design of the assays, the genus
Avipoxvirus
, which encodes major rearrangements of gene clusters, was excluded. These pan-pox assays amplify DNA from more than 150 different isolates and strains, including from primary clinical materials, from all seven targeted genera of chordopoxviruses and four unclassified new poxvirus species. The pan-pox assays represent an important advance for the screening and diagnosis of human and animal poxvirus infections, and the technology used is accessible to many laboratories worldwide.
Broadly Neutralizing Monoclonal Antibodies 2F5 and 4E10 Directed against the Human Immunodeficiency Virus Type 1 gp41 Membrane-Proximal External Region Protect against Mucosal Challenge by Simian-Human Immunodeficiency Virus SHIVBa-L
Authors: Hessell Ann J. , Rakasz Eva G. , Tehrani David M. , Huber Michael , Weisgrau Kimberly L. , Landucci Gary , Forthal Donald N. , Koff Wayne C. , Poignard Pascal , Watkins David I. , Burton Dennis R.
Published: November 2009

The membrane-proximal external region (MPER) of HIV-1, located at the C terminus of the gp41 ectodomain, is conserved and crucial for viral fusion. Three broadly neutralizing monoclonal antibodies (bnMAbs), 2F5, 4E10, and Z13e1, are directed against linear epitopes mapped to the MPER, making this conserved region an important potential vaccine target. However, no MPER antibodies have been definitively shown to provide protection against HIV challenge. Here, we show that both MAbs 2F5 and 4E10 can provide complete protection against mucosal simian-human immunodeficiency virus (SHIV) challenge in macaques. MAb 2F5 or 4E10 was administered intravenously at 50 mg/kg to groups of six male Indian rhesus macaques 1 day prior to and again 1 day following intrarectal challenge with SHIVBa-L. In both groups, five out of six animals showed complete protection and sterilizing immunity, while for one animal in each group a low level of viral replication following challenge could not be ruled out. The study confirms the protective potential of 2F5 and 4E10 and supports emphasis on HIV immunogen design based on the MPER region of gp41.
Structure of the Nucleoprotein Binding Domain of Mokola Virus Phosphoprotein
Authors: Assenberg René , Delmas Olivier , Ren Jingshan , Vidalain Pierre-Olivier , Verma Anil , Larrous Florence , Graham Stephen C. , Tangy Frédéric , Grimes Jonathan M. , Bourhy Hervé
Published: November 2009

Mokola virus (MOKV) is a nonsegmented, negative-sense RNA virus that belongs to the
Lyssavirus
genus and
Rhabdoviridae
family. MOKV phosphoprotein P is an essential component of the replication and transcription complex and acts as a cofactor for the viral RNA-dependent RNA polymerase. P recruits the viral polymerase to the nucleoprotein-bound viral RNA (N-RNA) via an interaction between its C-terminal domain and the N-RNA complex. Here we present a structure for this domain of MOKV P, obtained by expression of full-length P in
Escherichia coli
, which was subsequently truncated during crystallization. The structure has a high degree of homology with P of rabies virus, another member of
Lyssavirus
genus, and to a lesser degree with P of vesicular stomatitis virus (VSV), a member of the related
Vesiculovirus
genus. In addition, analysis of the crystal packing of this domain reveals a potential binding site for the nucleoprotein N. Using both site-directed mutagenesis and yeast two-hybrid experiments to measure P-N interaction, we have determined the relative roles of key amino acids involved in this interaction to map the region of P that binds N. This analysis also reveals a structural relationship between the N-RNA binding domain of the P proteins of the
Rhabdoviridae
and the
Paramyxoviridae
.
Nuclear Import and Assembly of Influenza A Virus RNA Polymerase Studied in Live Cells by Fluorescence Cross-Correlation Spectroscopy
Authors: Huet Sébastien , Avilov Sergiy V. , Ferbitz Lars , Daigle Nathalie , Cusack Stephen , Ellenberg Jan
Published: November 2009

Intracellular transport and assembly of the subunits of the heterotrimeric RNA-dependent RNA polymerase constitute a key component of the replication cycle of influenza virus. Recent results suggest that efficient polymerase assembly is a limiting factor in the viability of reassortant viruses. The mechanism of nuclear import and assembly of the three polymerase subunits, PB1, PB2, and PA, is still controversial, yet it is clearly of great significance in understanding the emergence of new strains with pandemic potential. In this study, we systematically investigated the interactions between the polymerase subunits and their localization in living cells by fluorescence cross-correlation spectroscopy (FCCS) and quantitative confocal microscopy. We could show that PB1 and PA form a dimer in the cytoplasm, which is imported into the nucleus separately from PB2. Once in the nucleus, the PB1/PA dimer associates with PB2 to form the trimeric polymerase. Photon-counting histogram analysis revealed that trimeric polymerase complexes can form higher-order oligomers in the nucleus. We furthermore demonstrate that impairing the nuclear import of PB2 by mutating its nuclear localization signal leads to abnormal formation of the trimeric polymerase in the cytoplasm. Taken together, our results demonstrate which of the previously discussed influenza virus polymerase transport models operates in live cells. Our study sheds light on the interplay between the nuclear import of the subunits and the assembly of the influenza virus polymerase and provides a methodological framework to analyze the effects of different host range mutations in the future.
Chimeric Feline Coronaviruses That Encode Type II Spike Protein on Type I Genetic Background Display Accelerated Viral Growth and Altered Receptor Usage
Authors: Tekes Gergely , Hofmann-Lehmann Regina , Bank-Wolf Barbara , Maier Reinhard , Thiel Heinz-Jürgen , Thiel Volker
Published: November 2009

Persistent infection of domestic cats with feline coronaviruses (FCoVs) can lead to a highly lethal, immunopathological disease termed feline infectious peritonitis (FIP). Interestingly, there are two serotypes, type I and type II FCoVs, that can cause both persistent infection and FIP, even though their main determinant of host cell tropism, the spike (S) protein, is of different phylogeny and displays limited sequence identity. In cell culture, however, there are apparent differences. Type II FCoVs can be propagated to high titers by employing feline aminopeptidase N (fAPN) as a cellular receptor, whereas the propagation of type I FCoVs is usually difficult, and the involvement of fAPN as a receptor is controversial. In this study we have analyzed the phenotypes of recombinant FCoVs that are based on the genetic background of type I FCoV strain Black but encode the type II FCoV strain 79-1146 S protein. Our data demonstrate that recombinant FCoVs expressing a type II FCoV S protein acquire the ability to efficiently use fAPN for host cell entry and corroborate the notion that type I FCoVs use another main host cell receptor. We also observed that recombinant FCoVs display a large-plaque phenotype and, unexpectedly, accelerated growth kinetics indistinguishable from that of type II FCoV strain 79-1146. Thus, the main phenotypic differences for type I and type II FCoVs in cell culture, namely, the growth kinetics and the efficient usage of fAPN as a cellular receptor, can be attributed solely to the FCoV S protein.
HIV Infection Is Associated with a Preferential Decline in Less-Differentiated CD56dimCD16+NK Cells
Authors: Hong Henoch S. , Eberhard Johanna M. , Keudel Phillip , Bollmann Benjamin A. , Ballmaier Matthias , Bhatnagar Nupur , Zielinska-Skowronek Margot , Schmidt Reinhold E. , Meyer-Olson Dirk
Published: November 2009

HIV-1 infection is characterized by loss of CD56dimCD16+NK cells and increased terminal differentiation on various lymphocyte subsets. We identified a decrease of CD57−and CD57dimcells but not of CD57brightcells on CD56dimCD16+NK cells in chronic HIV infection. Increasing CD57 expression was strongly associated with increasing frequencies of killer immunoglobulin-like receptors (KIRs) and granzyme B-expressing cells but decreasing percentages of cells expressing CD27+, HLA-DR+, Ki-67+, and CD107a. Our data indicate that HIV leads to a decline of less-differentiated cells and suggest that CD57 is a useful marker for terminal differentiation on NK cells.
Viral Mutagenesis as a Means for Generating Novel Proteins
Authors: Davis John N. , van den Pol Anthony N.
Published: November 2009

We demonstrate that a mutation-prone virus engineered to express a foreign gene is an expedient means for generating novel mutant nonviral proteins in mammalian cells. Using vesicular stomatitis virus to express a gene coding for a fluorescent DsRed protein, a number of green mutant variants including a new variant not previously described were rapidly isolated from infected cells, sequenced, and cloned. Similar methods may be useful in the development of physiologically sensitive fluorescent reporter proteins and directed evolution or mutagenesis of proteins in general.
Androgen Stimulates Transcription and Replication of Xenotropic Murine Leukemia Virus-Related Virus
Authors: Dong Beihua , Silverman Robert H.
Published: November 2009

Xenotropic murine leukemia virus-related virus (XMRV) is a gammaretrovirus originally identified in a subset of prostate cancer patients. Because androgens stimulate prostate tumors and some retroviruses, we investigated the effects of dihydrotestosterone (DHT) on XMRV transcription and replication. Transcription from the XMRV U3 region was stimulated up to 2-fold by DHT, but only in cells containing a functional androgen receptor. Mutations in the glucocorticoid response element (GRE) of XMRV impaired basal transcription and androgen responsiveness. Furthermore, DHT stimulated XMRV replication 3-fold, whereas androgen inhibitors (casodex and flutamide) suppressed viral growth up to 3-fold. Findings suggest that integration of the XMRV long terminal repeat (LTR) into host DNA could impart androgen stimulation on cellular genes.
A Single-Dose Influenza A (H5N1) Vaccine Safe and Immunogenic in Adult and Elderly Patients: an Approach to Pandemic Vaccine Development
Authors: Vajo Zoltan , Wood John , Kosa Lajos , Szilvasy Istvan , Paragh Gyorgy , Pauliny Zsuzsanna , Bartha Kálmán , Visontay Ildiko , Kis Agnes , Jankovics Istvan
Published: November 2009

With the ongoing pandemic of influenza A (H1N1) virus infection and the threat of high fatality rates for recent human cases of infection with highly pathogenic H5N1 strains, there has been considerable interest in developing pandemic vaccines. Here we report a randomized multicenter dose-finding clinical trial of a whole-virion, inactivated, adjuvanted H5N1 vaccine in adult and elderly volunteers. Four hundred eighty patients were randomly assigned to receive one or two doses of 3.5 μg of the vaccine or one dose of 6 or 12 μg. The subjects were monitored for safety analysis, and serum samples were obtained to assess immunogenicity by hemagglutination inhibition and microneutralization tests. The subjects developed antibody responses against the influenza A (H5N1) virus. Single doses of ≥6 μg fulfilled EU and U.S. licensing criteria for interpandemic and pandemic influenza vaccines. Except for occasional injection site pain, malaise, and fever, no adverse events were observed. We found that the present vaccine is safe and immunogenic in healthy adult and elderly subjects and requires low doses and, unlike any other H5N1 vaccines, only one injection to trigger immune responses which comply with licensing criteria. A vaccine using the same methods as those described in this report, but based on a wild-type swine-origin 2009 (H1N1) influenza A virus isolate from the United States (supplied by the CDC), has been developed and is currently being tested by our group.
Papillomavirus Prophylactic Vaccines: Established Successes, New Approaches
Authors: Campo M. Saveria , Roden Richard B. S.
Published: November 2009

Vaccines against the human papillomaviruses (HPVs) most frequently associated with cancer of the cervix are now available. These prophylactic vaccines, based on virus-like particles (VLPs), are extremely effective, providing protection from infection in almost 100% of cases. However, the vaccines present some limitations: they are effective primarily against the HPV type present in the vaccine, are expensive to produce, and need a cold chain. Vaccines based on the minor capsid protein L2 have been very successful in animal models and have been shown to provide a good level of protection against different papillomavirus types. The potential of L2-based vaccines to protect against many types of HPVs is discussed.
NS1′ of Flaviviruses in the Japanese Encephalitis Virus Serogroup Is a Product of Ribosomal Frameshifting and Plays a Role in Viral Neuroinvasiveness
Authors: Melian Ezequiel Balmori , Hinzman Edward , Nagasaki Tomoko , Firth Andrew E. , Wills Norma M. , Nouwens Amanda S. , Blitvich Bradley J. , Leung Jason , Funk Anneke , Atkins John F. , Hall Roy , Khromykh Alexander A.
Published: November 2009

Flavivirus NS1 is a nonstructural protein involved in virus replication and regulation of the innate immune response. Interestingly, a larger NS1-related protein, NS1′, is often detected during infection with the members of the Japanese encephalitis virus serogroup of flaviviruses. However, how NS1′ is made and what role it performs in the viral life cycle have not been determined. Here we provide experimental evidence that NS1′ is the product of a −1 ribosomal frameshift event that occurs at a conserved slippery heptanucleotide motif located near the beginning of the NS2A gene and is stimulated by a downstream RNA pseudoknot structure. Using site-directed mutagenesis of these sequence elements in an infectious clone of the Kunjin subtype of West Nile virus, we demonstrate that NS1′ plays a role in viral neuroinvasiveness.
Herpes Simplex Virus Tegument ICP0 Is Capsid Associated, and Its E3 Ubiquitin Ligase Domain Is Important for Incorporation into Virions
Authors: Delboy Mark G. , Siekavizza-Robles Carlos R. , Nicola Anthony V.
Published: November 2009

Herpes simplex virus (HSV) immediate-early (IE) protein ICP0 is a multifunctional regulator of HSV infection. ICP0 that is present in the tegument layer has not been well characterized. Protein compositions of wild-type and ICP0 null virions were similar, suggesting that the absence of ICP0 does not grossly impair virion assembly. ICP0 has a RING finger domain with E3 ubiquitin ligase activity that is necessary for IE functions. Virions with mutations in this domain contained greatly reduced levels of tegument ICP0, suggesting that the domain influences the incorporation of ICP0. Virion ICP0 was resistant to removal by detergent and salt and was associated with capsids, features common to inner tegument proteins.
Molecular Epidemiology of Simian Immunodeficiency Virus Infection in Wild-Living Gorillas
Authors: Neel Cécile , Etienne Lucie , Li Yingying , Takehisa Jun , Rudicell Rebecca S. , Ndong Bass Innocent , Moudindo Joseph , Mebenga Aimé , Esteban Amandine , Van Heuverswyn Fran , Liegeois Florian , Kranzusch Philip J. , Walsh Peter D. , Sanz Crickette M. , Morgan David B. , Ndjango Jean-Bosco N. , Plantier Jean-Christophe , Locatelli Sabrina , Gonder Mary K. , Leendertz Fabian H. , Boesch Christophe , Todd Angelique , Delaporte Eric , Mpoudi-Ngole Eitel , Hahn Beatrice H. , Peeters Martine
Published: November 2009

Chimpanzees and gorillas are the only nonhuman primates known to harbor viruses closely related to HIV-1. Phylogenetic analyses showed that gorillas acquired the simian immunodeficiency virus SIVgor from chimpanzees, and viruses from the SIVcpz/SIVgor lineage have been transmitted to humans on at least four occasions, leading to HIV-1 groups M, N, O, and P. To determine the geographic distribution, prevalence, and species association of SIVgor, we conducted a comprehensive molecular epidemiological survey of wild gorillas in Central Africa. Gorilla fecal samples were collected in the range of western lowland gorillas (
n
= 2,367) and eastern Grauer gorillas (
n
= 183) and tested for SIVgor antibodies and nucleic acids. SIVgor antibody-positive samples were identified at 2 sites in Cameroon, with no evidence of infection at 19 other sites, including 3 in the range of the Eastern gorillas. In Cameroon, based on DNA and microsatellite analyses of a subset of samples, we estimated the prevalence of SIVgor to be 1.6% (range, 0% to 4.6%), which is significantly lower than the prevalence of SIVcpz
Ptt
in chimpanzees (5.9%; range, 0% to 32%). All newly identified SIVgor strains formed a monophyletic lineage within the SIVcpz radiation, closely related to HIV-1 groups O and P, and clustered according to their field site of origin. At one site, there was evidence for intergroup transmission and a high intragroup prevalence. These isolated hot spots of SIVgor-infected gorilla communities could serve as a source for human infection. The overall low prevalence and sporadic distribution of SIVgor could suggest a decline of SIVgor in wild populations, but it cannot be excluded that SIVgor is still more prevalent in other parts of the geographical range of gorillas.
Relationship of DDE/ΣDDT in Marine Mammals to the Chronology of DDT Input into the Ecosystem
Authors: Aguilar Alex
Published: November 2009

The DDE/ΣDDT (ΣDDT = DDT + DDE + DDD) ratios in the blubber of North Atlantic pinnipeds and odontocete cetaceans, as determined by several scientists and surveys, are compiled to obtain a biannual mean series. Conversion of DDT to DDE is interpreted as being due not only to the marine mammals but also to the overall detoxifying activity of the North Atlantic marine biota. The change of these ratios during the period 1964–81 is examined and a strong correlation between these ratios and time is found in both groups, which demonstrates that such an index can be tentatively used when one assesses the chronology of pollutant input into the ecosystem. An equilibrium value may be reached at the beginning of the next century when the ratio reaches a value of approximately 0.60, provided that no new inputs of contaminant into North Atlantic waters exist.
Biochemical Population Genetics of Pacific Herring (Clupea pallasi)
Authors: Grant W. Stewart , Utter Fred M.
Published: November 2009

Studies of stock structure in Pacific herring (Clupea pallasi) using geographic variation in morphology and growth, and tagging methods, have shown that Pacific herring are subdivided into numerous more or less distinct populations or stocks having limited migration between stocks. Homing of adults to previous spawning areas and larval retention mechanisms may enhance reproductive isolation between spawning areas and have been postulated to produce genetic differences between stocks. In this study the geographic distributions of inherited biochemical markers were used to measure the genetic component of stock structure in Pacific herring. The gene products of 40 protein-coding loci were examined by starch–gel electrophoresis in 21 samples collected from locations extending over most of the range of Pacific herring in the North Pacific Ocean and Bering Sea. These results show that there is a very small genetic component to the stock structure described by nongenetic methods. No significant allele-frequency differences were detected among three samples of Asian herring. In the eastern Bering Sea, the northern populations were genetically distinct from southern populations on the Seward Peninsula and in Bristol Bay, but no genetic structure was detected within these areas. In the eastern North Pacific Ocean, the Gulf of Alaska populations were genetically distinct from the remaining southern populations. Some genetic structure was detected in the Gulf of Alaska but not among the remaining southern populations. Using the stepping-stone model of migration and the observed amount of genetic divergence among populations, we show that small-scale genetic differences would not be expected, given the amount of migration observed between spawning areas. Another important result of this study is the discovery of two genetic races, Asian–Bering Sea herring and eastern North Pacific herring, having an average Nei genetic distance (D) between samples of the two races of 0.039; D between populations within each race averaged 0.0009. We postulate that the two North Pacific races of herring arose as a result of repeated Pleistocene glaciation on the southern coast of Alaska, which created a barrier to gene flow and permitted the two oceanic groups to diverge genetically.
Uptake of Chlorinated Organics from Anthropogenically Contaminated Sediments by Oligochaete Worms
Authors: Oliver Barry G.
Published: November 2009

Oligochaete worms, mainly Limnodrilus hoffmeisteri and Tubifex tubifex, were exposed to "naturally" contaminated sediments from Lake Ontario for 110 d in laboratory aquariums. The worms accumulated many of the 24 chlorinated chemicals studied and for most compounds, concentration factors (CF's) continued to increase over the 110-d study period. The mixture of chemicals found in the worms differed considerably from that in the sediments because of large variations in CF's between chemicals. For instance, several individual PCB congeners were studied and found to have different CF's. Smaller differences in CF's for individual chemicals were due to different sediment types and to different worm sizes. The relationship between CF and octanol–water partition coefficient of the chemicals was complex.
Structural, Functional, and Recovery Responses of Stream Invertebrates to Fly Ash Effluent
Authors: Specht Winona L. , Cherry Donald S. , Lechleitner Richard A. , Cairns Jr. John
Published: November 2009

Small fly ash settling ponds (e.g. 2-yr life time) should not be used after they are ~87–90% full when effluents are released into lotic systems. When our pond was > 90% full, mayflies (Stenonema, Heptagenia, Paraleptophlebia), stoneflies (Acroneuria), and caddisflies (Cheumatopsyche) were significantly (α = 0.05) reduced in density, number of taxa, and diversity in the stream receiving system. Highly resistant coleopterans (e.g. Psephenus herricki) became the dominant species. Two to 10 mo were required for the insect community to recover after cessation of ash effluent. Potential lethal effects of fly ash may result from ash particles, heavy metal, and other elements (especially As and Se), and alkaline pH increases above 9.0. Which fraction of fly ash is most limiting to each insect group or species needs far more examination. Ash particle concentrations (total suspended solids, [Formula: see text]) were not acutely toxic in 96-h laboratory bioassays to sensitive mayflies (Stenonema pudicum) or resistant coleopterans (P. herricki), nor were heavy metals (Cd, Cu, Zn) at concentrations similar to those found in the fly ash effluent, although data are lacking to evaluate long-term (e.g. [Formula: see text]) effects. Alkaline pH exposures need more research, since the 96-h LC50 of 9.5 for S. pudicum was similar to pH values observed in the receiving stream during summer low-flow, high-temperature conditions when the ash pond was > 95% full.
A Biologically Meaningful Approach to Response Surface Analysis
Authors: Schnute Jon , McKinnell Skip
Published: November 2009

Response surface analysis is commonly used to summarize the results of a complex biological experiment. The technique produces a quadratic function that relates experimental conditions (factors) to biological response, where the quadratic behavior allows for a possible optimum. Typically, the variables in this function are transformed to give the model greater flexibility. In fisheries literature, exponential transformations (with exponents presumed unknown) have been widely applied. Although properties of the quadratic model are well documented, the surface features that result from exponential transformations are not. Frequently, the practitioner obtains parameter estimates with widely varying magnitudes and contour plots that exhibit strange and confusing distortions. The parameters may bear no apparent relationship to the surface and, consequently, may appear to be useless pieces of information. This paper defines new parameters for the quadratic model with exponential transformations and demonstrates precisely the role of each parameter in determining the shape of the surface. The parameters have the added advantage that numerical methods to estimate them perform efficiently, thus avoiding convergence problems sometimes encountered in the past. Statistical error is discussed, analytically and intuitively in terms of model parameters. Evidence is given that one of the transformations may be wrong in fisheries applications, and a reasonable alternative is proposed. Worked examples from historical literature illustrate all aspects of the new approach and show how both quantitative and qualitative errors can be avoided through biological understanding of the significance of every parameter.
Metal Toxicity to Algae: A Highly pH Dependent Phenomenon
Authors: Peterson Hans G. , Healey F. Patrick , Wagemann Rudolf
Published: November 2009

The inhibitory effect of Cd and of Cu on P uptake by the green alga Scenedesmus quadricauda is a highly pH dependent process. We used a simple inorganic medium to minimize the effects of variables other than pH so that changes in toxicity should reflect changes related only to H+concentration. The toxicity of Cd to P uptake increases strongly (almost 200-fold) with increasing pH over the range 5.5–8.5. Hydrated Cd2+dominates the dissolved Cd pool over this pH range. The logarithm of the Cd concentration causing 50% inhibition of P uptake is linearly related to pH. Total Cu toxicity increases 76-fold from pH 5.0 to 6.5, where hydrated Cu2+is the dominant dissolved Cu species, and then remains relatively constant at higher pH, where uncharged inorganic Cu complexes are dominant. The logarithm of the Cu2+concentration causing 50% inhibition of P uptake was also linearly related to pH, but total Cu was not. We explain this variation in metal toxicity with pH as a competition between H+and free metal cations for cellular binding sites. Possibly this is a general phenomenon for metals that form a significant amount of free cations relative to the total metal pool.